{"id":1362,"date":"2008-12-29T00:44:46","date_gmt":"2008-12-29T00:44:46","guid":{"rendered":"http:\/\/127.0.0.1\/blog2\/?p=1362"},"modified":"2008-12-29T00:44:46","modified_gmt":"2008-12-29T00:44:46","slug":"java-%e7%ac%94%e8%af%95%e9%a2%98%e5%a4%a7%e5%85%a81","status":"publish","type":"post","link":"https:\/\/opgogo.com\/blog2\/?p=1362","title":{"rendered":"java \u7b14\u8bd5\u9898\u5927\u51681"},"content":{"rendered":"

java \u7b14\u8bd5\u9898\u5927\u5168<\/p>\n

Java\u57fa\u7840\u65b9\u9762:<\/p>\n

0\u3001\u4f5c\u7528\u57dfpublic,private,protected,\u4ee5\u53ca\u4e0d\u5199\u65f6\u7684\u533a\u522b
\n\u7b54\uff1a\u533a\u522b\u5982\u4e0b\uff1a
\n\u4f5c\u7528\u57df \u5f53\u524d\u7c7b \u540c\u4e00package \u5b50\u5b59\u7c7b \u5176\u4ed6package
\npublic \u221a \u221a \u221a \u221a
\nprotected \u221a \u221a \u221a \u00d7
\nfriendly \u221a \u221a \u00d7 \u00d7
\nprivate \u221a \u00d7 \u00d7 \u00d7
\n\u4e0d\u5199\u65f6\u9ed8\u8ba4\u4e3afriendly<\/p>\n

1\u3002
\njava.lang.String\u7c7b\u662ffinal\u7c7b\u578b\u7684\uff0c\u56e0\u6b64\u4e0d\u53ef\u4ee5\u7ee7\u627f\u8fd9\u4e2a\u7c7b\u3001\u4e0d\u80fd\u4fee\u6539\u8fd9\u4e2a\u7c7b\u3002\u4e3a\u4e86\u63d0\u9ad8\u6548\u7387\u8282\u7701\u7a7a\u95f4\uff0c\u6211\u4eec\u5e94\u8be5\u7528StringBuffer\u7c7b<\/p>\n

3\u3001int \u548c Integer \u6709\u4ec0\u4e48\u533a\u522b
\nJava \u63d0\u4f9b\u4e24\u79cd\u4e0d\u540c\u7684\u7c7b\u578b\uff1a\u5f15\u7528\u7c7b\u578b\u548c\u539f\u59cb\u7c7b\u578b\uff08\u6216\u5185\u7f6e\u7c7b\u578b\uff09\u3002Int\u662fjava\u7684\u539f\u59cb\u6570\u636e\u7c7b\u578b\uff0cInteger\u662fjava\u4e3aint\u63d0\u4f9b\u7684\u5c01\u88c5\u7c7b\u3002Java\u4e3a\u6bcf\u4e2a\u539f\u59cb\u7c7b\u578b\u63d0\u4f9b\u4e86\u5c01\u88c5\u7c7b\u3002
\n\u539f\u59cb\u7c7b\u578b\u5c01\u88c5\u7c7b
\nbooleanBoolean
\ncharCharacter
\nbyteByte
\nshortShort
\nintInteger
\nlongLong
\nfloatFloat
\ndoubleDouble
\n\u5f15 \u7528\u7c7b\u578b\u548c\u539f\u59cb\u7c7b\u578b\u7684\u884c\u4e3a\u5b8c\u5168\u4e0d\u540c\uff0c\u5e76\u4e14\u5b83\u4eec\u5177\u6709\u4e0d\u540c\u7684\u8bed\u4e49\u3002\u5f15\u7528\u7c7b\u578b\u548c\u539f\u59cb\u7c7b\u578b\u5177\u6709\u4e0d\u540c\u7684\u7279\u5f81\u548c\u7528\u6cd5\uff0c\u5b83\u4eec\u5305\u62ec\uff1a\u5927\u5c0f\u548c\u901f\u5ea6\u95ee\u9898\uff0c\u8fd9\u79cd\u7c7b\u578b\u4ee5\u54ea\u79cd\u7c7b\u578b\u7684\u6570 \u636e\u7ed3\u6784\u5b58\u50a8\uff0c\u5f53\u5f15\u7528\u7c7b\u578b\u548c\u539f\u59cb\u7c7b\u578b\u7528\u4f5c\u67d0\u4e2a\u7c7b\u7684\u5b9e\u4f8b\u6570\u636e\u65f6\u6240\u6307\u5b9a\u7684\u7f3a\u7701\u503c\u3002\u5bf9\u8c61\u5f15\u7528\u5b9e\u4f8b\u53d8\u91cf\u7684\u7f3a\u7701\u503c\u4e3a null\uff0c\u800c\u539f\u59cb\u7c7b\u578b\u5b9e\u4f8b\u53d8\u91cf\u7684\u7f3a\u7701\u503c\u4e0e\u5b83\u4eec\u7684\u7c7b\u578b\u6709\u5173\u3002<\/p>\n

4\u3001String \u548cStringBuffer\u7684\u533a\u522b
\nJAVA \u5e73\u53f0\u63d0\u4f9b\u4e86\u4e24\u4e2a\u7c7b\uff1aString\u548cStringBuffer\uff0c\u5b83\u4eec\u53ef\u4ee5\u50a8\u5b58\u548c\u64cd\u4f5c\u5b57\u7b26\u4e32\uff0c\u5373\u5305\u542b\u591a\u4e2a\u5b57\u7b26\u7684\u5b57\u7b26\u6570\u636e\u3002\u8fd9\u4e2aString\u7c7b\u63d0\u4f9b\u4e86\u6570\u503c\u4e0d\u53ef\u6539 \u53d8\u7684\u5b57\u7b26\u4e32\u3002\u800c\u8fd9\u4e2aStringBuffer\u7c7b\u63d0\u4f9b\u7684\u5b57\u7b26\u4e32\u8fdb\u884c\u4fee\u6539\u3002\u5f53\u4f60\u77e5\u9053\u5b57\u7b26\u6570\u636e\u8981\u6539\u53d8\u7684\u65f6\u5019\u4f60\u5c31\u53ef\u4ee5\u4f7f\u7528StringBuffer\u3002\u5178\u578b\u5730\uff0c\u4f60\u53ef \u4ee5\u4f7f\u7528StringBuffers\u6765\u52a8\u6001\u6784\u9020\u5b57\u7b26\u6570\u636e\u3002<\/p>\n

5\u3001\u8fd0\u884c\u65f6\u5f02\u5e38\u4e0e\u4e00\u822c\u5f02\u5e38\u6709\u4f55\u5f02\u540c\uff1f
\n\u5f02\u5e38\u8868\u793a\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\u53ef\u80fd\u51fa\u73b0\u7684\u975e\u6b63\u5e38\u72b6\u6001\uff0c\u8fd0\u884c\u65f6\u5f02\u5e38\u8868\u793a\u865a\u62df\u673a\u7684\u901a\u5e38\u64cd\u4f5c\u4e2d\u53ef\u80fd\u9047\u5230\u7684\u5f02\u5e38\uff0c\u662f\u4e00\u79cd\u5e38\u89c1\u8fd0\u884c\u9519\u8bef\u3002java\u7f16\u8bd1\u5668\u8981\u6c42\u65b9\u6cd5\u5fc5\u987b\u58f0\u660e\u629b\u51fa\u53ef\u80fd\u53d1\u751f\u7684\u975e\u8fd0\u884c\u65f6\u5f02\u5e38\uff0c\u4f46\u662f\u5e76\u4e0d\u8981\u6c42\u5fc5\u987b\u58f0\u660e\u629b\u51fa\u672a\u88ab\u6355\u83b7\u7684\u8fd0\u884c\u65f6\u5f02\u5e38\u3002<\/p>\n

6\u3001\u8bf4\u51faServlet\u7684\u751f\u547d\u5468\u671f\uff0c\u5e76\u8bf4\u51faServlet\u548cCGI\u7684\u533a\u522b\u3002
\nServlet\u88ab\u670d\u52a1\u5668\u5b9e\u4f8b\u5316\u540e\uff0c\u5bb9\u5668\u8fd0\u884c\u5176init\u65b9\u6cd5\uff0c\u8bf7\u6c42\u5230\u8fbe\u65f6\u8fd0\u884c\u5176service\u65b9\u6cd5\uff0cservice\u65b9\u6cd5\u81ea\u52a8\u6d3e\u9063\u8fd0\u884c\u4e0e\u8bf7\u6c42\u5bf9\u5e94\u7684doXXX\u65b9\u6cd5\uff08doGet\uff0cdoPost\uff09\u7b49\uff0c\u5f53\u670d\u52a1\u5668\u51b3\u5b9a\u5c06\u5b9e\u4f8b\u9500\u6bc1\u7684\u65f6\u5019\u8c03\u7528\u5176destroy\u65b9\u6cd5\u3002
\n\u4e0ecgi\u7684\u533a\u522b\u5728\u4e8eservlet\u5904\u4e8e\u670d\u52a1\u5668\u8fdb\u7a0b\u4e2d\uff0c\u5b83\u901a\u8fc7\u591a\u7ebf\u7a0b\u65b9\u5f0f\u8fd0\u884c\u5176service\u65b9\u6cd5\uff0c\u4e00\u4e2a\u5b9e\u4f8b\u53ef\u4ee5\u670d\u52a1\u4e8e\u591a\u4e2a\u8bf7\u6c42\uff0c\u5e76\u4e14\u5176\u5b9e\u4f8b\u4e00\u822c\u4e0d\u4f1a\u9500\u6bc1\uff0c\u800cCGI\u5bf9\u6bcf\u4e2a\u8bf7\u6c42\u90fd\u4ea7\u751f\u65b0\u7684\u8fdb\u7a0b\uff0c\u670d\u52a1\u5b8c\u6210\u540e\u5c31\u9500\u6bc1\uff0c\u6240\u4ee5\u6548\u7387\u4e0a\u4f4e\u4e8eservlet\u3002<\/p>\n

7\u3001\u8bf4\u51faArrayList,Vector, LinkedList\u7684\u5b58\u50a8\u6027\u80fd\u548c\u7279\u6027
\nArrayList \u548cVector\u90fd\u662f\u4f7f\u7528\u6570\u7ec4\u65b9\u5f0f\u5b58\u50a8\u6570\u636e\uff0c\u6b64\u6570\u7ec4\u5143\u7d20\u6570\u5927\u4e8e\u5b9e\u9645\u5b58\u50a8\u7684\u6570\u636e\u4ee5\u4fbf\u589e\u52a0\u548c\u63d2\u5165\u5143\u7d20\uff0c\u5b83\u4eec\u90fd\u5141\u8bb8\u76f4\u63a5\u6309\u5e8f\u53f7\u7d22\u5f15\u5143\u7d20\uff0c\u4f46\u662f\u63d2\u5165\u5143\u7d20\u8981\u6d89\u53ca\u6570\u7ec4\u5143 \u7d20\u79fb\u52a8\u7b49\u5185\u5b58\u64cd\u4f5c\uff0c\u6240\u4ee5\u7d22\u5f15\u6570\u636e\u5feb\u800c\u63d2\u5165\u6570\u636e\u6162\uff0cVector\u7531\u4e8e\u4f7f\u7528\u4e86synchronized\u65b9\u6cd5\uff08\u7ebf\u7a0b\u5b89\u5168\uff09\uff0c\u901a\u5e38\u6027\u80fd\u4e0a\u8f83ArrayList\u5dee\uff0c \u800cLinkedList\u4f7f\u7528\u53cc\u5411\u94fe\u8868\u5b9e\u73b0\u5b58\u50a8\uff0c\u6309\u5e8f\u53f7\u7d22\u5f15\u6570\u636e\u9700\u8981\u8fdb\u884c\u524d\u5411\u6216\u540e\u5411\u904d\u5386\uff0c\u4f46\u662f\u63d2\u5165\u6570\u636e\u65f6\u53ea\u9700\u8981\u8bb0\u5f55\u672c\u9879\u7684\u524d\u540e\u9879\u5373\u53ef\uff0c\u6240\u4ee5\u63d2\u5165\u901f\u5ea6\u8f83\u5feb\u3002<\/p>\n

8\u3001EJB\u662f\u57fa\u4e8e\u54ea\u4e9b\u6280\u672f\u5b9e\u73b0\u7684\uff1f\u5e76\u8bf4\u51faSessionBean\u548cEntityBean\u7684\u533a\u522b\uff0cStatefulBean\u548cStatelessBean\u7684\u533a\u522b\u3002
\nEJB\u5305\u62ecSession Bean\u3001Entity Bean\u3001Message Driven Bean\uff0c\u57fa\u4e8eJNDI\u3001RMI\u3001JAT\u7b49\u6280\u672f\u5b9e\u73b0\u3002
\nSessionBean\u5728J2EE\u5e94\u7528\u7a0b\u5e8f\u4e2d\u88ab\u7528\u6765\u5b8c\u6210\u4e00\u4e9b\u670d\u52a1\u5668\u7aef\u7684\u4e1a\u52a1\u64cd\u4f5c\uff0c\u4f8b\u5982\u8bbf\u95ee\u6570\u636e\u5e93\u3001\u8c03\u7528\u5176\u4ed6EJB\u7ec4\u4ef6\u3002EntityBean\u88ab\u7528\u6765\u4ee3\u8868\u5e94\u7528\u7cfb\u7edf\u4e2d\u7528\u5230\u7684\u6570\u636e\u3002
\n\u5bf9\u4e8e\u5ba2\u6237\u673a\uff0cSessionBean\u662f\u4e00\u79cd\u975e\u6301\u4e45\u6027\u5bf9\u8c61\uff0c\u5b83\u5b9e\u73b0\u67d0\u4e9b\u5728\u670d\u52a1\u5668\u4e0a\u8fd0\u884c\u7684\u4e1a\u52a1\u903b\u8f91\u3002
\n\u5bf9\u4e8e\u5ba2\u6237\u673a\uff0cEntityBean\u662f\u4e00\u79cd\u6301\u4e45\u6027\u5bf9\u8c61\uff0c\u5b83\u4ee3\u8868\u4e00\u4e2a\u5b58\u50a8\u5728\u6301\u4e45\u6027\u5b58\u50a8\u5668\u4e2d\u7684\u5b9e\u4f53\u7684\u5bf9\u8c61\u89c6\u56fe\uff0c\u6216\u662f\u4e00\u4e2a\u7531\u73b0\u6709\u4f01\u4e1a\u5e94\u7528\u7a0b\u5e8f\u5b9e\u73b0\u7684\u5b9e\u4f53\u3002
\nSession Bean \u8fd8\u53ef\u4ee5\u518d\u7ec6\u5206\u4e3a Stateful Session Bean \u4e0e Stateless Session Bean \uff0c\u8fd9\u4e24\u79cd\u7684 Session Bean\u90fd\u53ef\u4ee5\u5c06\u7cfb\u7edf\u903b\u8f91\u653e\u5728 method\u4e4b\u4e2d\u6267\u884c\uff0c\u4e0d\u540c\u7684\u662f Stateful Session Bean \u53ef\u4ee5\u8bb0\u5f55\u547c\u53eb\u8005\u7684\u72b6\u6001\uff0c\u56e0\u6b64\u901a\u5e38\u6765\u8bf4\uff0c\u4e00\u4e2a\u4f7f\u7528\u8005\u4f1a\u6709\u4e00\u4e2a\u76f8\u5bf9\u5e94\u7684 Stateful Session Bean \u7684\u5b9e\u4f53\u3002Stateless Session Bean \u867d\u7136\u4e5f\u662f\u903b\u8f91\u7ec4\u4ef6\uff0c\u4f46\u662f\u4ed6\u5374\u4e0d\u8d1f\u8d23\u8bb0\u5f55\u4f7f\u7528\u8005\u72b6\u6001\uff0c\u4e5f\u5c31\u662f\u8bf4\u5f53\u4f7f\u7528\u8005\u547c\u53eb Stateless Session Bean \u7684\u65f6\u5019\uff0cEJB Container \u5e76\u4e0d\u4f1a\u627e\u5bfb\u7279\u5b9a\u7684 Stateless Session Bean \u7684\u5b9e\u4f53\u6765\u6267\u884c\u8fd9\u4e2a method\u3002\u6362\u8a00\u4e4b\uff0c\u5f88\u53ef\u80fd\u6570\u4e2a\u4f7f\u7528\u8005\u5728\u6267\u884c\u67d0\u4e2a Stateless Session Bean \u7684 methods \u65f6\uff0c\u4f1a\u662f\u540c\u4e00\u4e2a Bean \u7684 Instance \u5728\u6267\u884c\u3002\u4ece\u5185\u5b58\u65b9\u9762\u6765\u770b\uff0c Stateful Session Bean \u4e0e Stateless Session Bean \u6bd4\u8f83\uff0c Stateful Session Bean \u4f1a\u6d88\u8017 J2EE Server \u8f83\u591a\u7684\u5185\u5b58\uff0c\u7136\u800c Stateful Session Bean \u7684\u4f18\u52bf\u5374\u5728\u4e8e\u4ed6\u53ef\u4ee5\u7ef4\u6301\u4f7f\u7528\u8005\u7684\u72b6\u6001\u3002<\/p>\n

9\u3001Collection \u548c Collections\u7684\u533a\u522b\u3002
\n\u3000\u3000Collection\u662f\u96c6\u5408\u7c7b\u7684\u4e0a\u7ea7\u63a5\u53e3\uff0c\u7ee7\u627f\u4e0e\u4ed6\u7684\u63a5\u53e3\u4e3b\u8981\u6709Set \u548cList.
\nCollections\u662f\u9488\u5bf9\u96c6\u5408\u7c7b\u7684\u4e00\u4e2a\u5e2e\u52a9\u7c7b\uff0c\u4ed6\u63d0\u4f9b\u4e00\u7cfb\u5217\u9759\u6001\u65b9\u6cd5\u5b9e\u73b0\u5bf9\u5404\u79cd\u96c6\u5408\u7684\u641c\u7d22\u3001\u6392\u5e8f\u3001\u7ebf\u7a0b\u5b89\u5168\u5316\u7b49\u64cd\u4f5c\u3002<\/p>\n

10\u3001&\u548c&&\u7684\u533a\u522b\u3002
\n&\u662f\u4f4d\u8fd0\u7b97\u7b26\uff0c\u8868\u793a\u6309\u4f4d\u4e0e\u8fd0\u7b97\uff0c&&\u662f\u903b\u8f91\u8fd0\u7b97\u7b26\uff0c\u8868\u793a\u903b\u8f91\u4e0e\uff08and\uff09\u3002<\/p>\n

11\u3001HashMap\u548cHashtable\u7684\u533a\u522b\u3002
\nHashMap\u662fHashtable\u7684\u8f7b\u91cf\u7ea7\u5b9e\u73b0\uff08\u975e\u7ebf\u7a0b\u5b89\u5168\u7684\u5b9e\u73b0\uff09\uff0c\u4ed6\u4eec\u90fd\u5b8c\u6210\u4e86Map\u63a5\u53e3\uff0c\u4e3b\u8981\u533a\u522b\u5728\u4e8eHashMap\u5141\u8bb8\u7a7a\uff08null\uff09\u952e\u503c\uff08key\uff09,\u7531\u4e8e\u975e\u7ebf\u7a0b\u5b89\u5168\uff0c\u6548\u7387\u4e0a\u53ef\u80fd\u9ad8\u4e8eHashtable\u3002
\nHashMap\u5141\u8bb8\u5c06null\u4f5c\u4e3a\u4e00\u4e2aentry\u7684key\u6216\u8005value\uff0c\u800cHashtable\u4e0d\u5141\u8bb8\u3002
\nHashMap\u628aHashtable\u7684contains\u65b9\u6cd5\u53bb\u6389\u4e86\uff0c\u6539\u6210containsvalue\u548ccontainsKey\u3002\u56e0\u4e3acontains\u65b9\u6cd5\u5bb9\u6613\u8ba9\u4eba\u5f15\u8d77\u8bef\u89e3\u3002
\nHashtable\u7ee7\u627f\u81eaDictionary\u7c7b\uff0c\u800cHashMap\u662fJava1.2\u5f15\u8fdb\u7684Map interface\u7684\u4e00\u4e2a\u5b9e\u73b0\u3002
\n\u6700\u5927\u7684\u4e0d\u540c\u662f\uff0cHashtable\u7684\u65b9\u6cd5\u662fSynchronize\u7684\uff0c\u800cHashMap\u4e0d\u662f\uff0c\u5728\u591a\u4e2a\u7ebf\u7a0b\u8bbf\u95eeHashtable\u65f6\uff0c\u4e0d\u9700\u8981\u81ea\u5df1\u4e3a\u5b83\u7684\u65b9\u6cd5\u5b9e\u73b0\u540c\u6b65\uff0c\u800cHashMap \u5c31\u5fc5\u987b\u4e3a\u4e4b\u63d0\u4f9b\u5916\u540c\u6b65\u3002
\nHashtable\u548cHashMap\u91c7\u7528\u7684hash\/rehash\u7b97\u6cd5\u90fd\u5927\u6982\u4e00\u6837\uff0c\u6240\u4ee5\u6027\u80fd\u4e0d\u4f1a\u6709\u5f88\u5927\u7684\u5dee\u5f02\u3002<\/p>\n

12\u3001final, finally, finalize\u7684\u533a\u522b\u3002
\n\u3000\u3000final \u7528\u4e8e\u58f0\u660e\u5c5e\u6027\uff0c\u65b9\u6cd5\u548c\u7c7b\uff0c\u5206\u522b\u8868\u793a\u5c5e\u6027\u4e0d\u53ef\u53d8\uff0c\u65b9\u6cd5\u4e0d\u53ef\u8986\u76d6\uff0c\u7c7b\u4e0d\u53ef\u7ee7\u627f\u3002
\nfinally\u662f\u5f02\u5e38\u5904\u7406\u8bed\u53e5\u7ed3\u6784\u7684\u4e00\u90e8\u5206\uff0c\u8868\u793a\u603b\u662f\u6267\u884c\u3002
\nfinalize\u662fObject\u7c7b\u7684\u4e00\u4e2a\u65b9\u6cd5\uff0c\u5728\u5783\u573e\u6536\u96c6\u5668\u6267\u884c\u7684\u65f6\u5019\u4f1a\u8c03\u7528\u88ab\u56de\u6536\u5bf9\u8c61\u7684\u6b64\u65b9\u6cd5\uff0c\u53ef\u4ee5\u8986\u76d6\u6b64\u65b9\u6cd5\u63d0\u4f9b\u5783\u573e\u6536\u96c6\u65f6\u7684\u5176\u4ed6\u8d44\u6e90\u56de\u6536\uff0c\u4f8b\u5982\u5173\u95ed\u6587\u4ef6\u7b49\u3002<\/p>\n

13\u3001sleep() \u548c wait() \u6709\u4ec0\u4e48\u533a\u522b?
\nsleep\u662f\u7ebf\u7a0b\u7c7b\uff08Thread\uff09\u7684\u65b9\u6cd5\uff0c\u5bfc\u81f4\u6b64\u7ebf\u7a0b\u6682\u505c\u6267\u884c\u6307\u5b9a\u65f6\u95f4\uff0c\u7ed9\u6267\u884c\u673a\u4f1a\u7ed9\u5176\u4ed6\u7ebf\u7a0b\uff0c\u4f46\u662f\u76d1\u63a7\u72b6\u6001\u4f9d\u7136\u4fdd\u6301\uff0c\u5230\u65f6\u540e\u4f1a\u81ea\u52a8\u6062\u590d\u3002\u8c03\u7528sleep\u4e0d\u4f1a\u91ca\u653e\u5bf9\u8c61\u9501\u3002
\nwait\u662fObject\u7c7b\u7684\u65b9\u6cd5\uff0c\u5bf9\u6b64\u5bf9\u8c61\u8c03\u7528wait\u65b9\u6cd5\u5bfc\u81f4\u672c\u7ebf\u7a0b\u653e\u5f03\u5bf9\u8c61\u9501\uff0c\u8fdb\u5165\u7b49\u5f85\u6b64\u5bf9\u8c61\u7684\u7b49\u5f85\u9501\u5b9a\u6c60\uff0c\u53ea\u6709\u9488\u5bf9\u6b64\u5bf9\u8c61\u53d1\u51fanotify\u65b9\u6cd5\uff08\u6216notifyAll\uff09\u540e\u672c\u7ebf\u7a0b\u624d\u8fdb\u5165\u5bf9\u8c61\u9501\u5b9a\u6c60\u51c6\u5907\u83b7\u5f97\u5bf9\u8c61\u9501\u8fdb\u5165\u8fd0\u884c\u72b6\u6001\u3002<\/p>\n

14\u3001Overload\u548cOverride\u7684\u533a\u522b\u3002Overloaded\u7684\u65b9\u6cd5\u662f\u5426\u53ef\u4ee5\u6539\u53d8\u8fd4\u56de\u503c\u7684\u7c7b\u578b?
\n\u65b9 \u6cd5\u7684\u91cd\u5199Overriding\u548c\u91cd\u8f7dOverloading\u662fJava\u591a\u6001\u6027\u7684\u4e0d\u540c\u8868\u73b0\u3002\u91cd\u5199Overriding\u662f\u7236\u7c7b\u4e0e\u5b50\u7c7b\u4e4b\u95f4\u591a\u6001\u6027\u7684\u4e00\u79cd\u8868\u73b0\uff0c\u91cd \u8f7dOverloading\u662f\u4e00\u4e2a\u7c7b\u4e2d\u591a\u6001\u6027\u7684\u4e00\u79cd\u8868\u73b0\u3002\u5982\u679c\u5728\u5b50\u7c7b\u4e2d\u5b9a\u4e49\u67d0\u65b9\u6cd5\u4e0e\u5176\u7236\u7c7b\u6709\u76f8\u540c\u7684\u540d\u79f0\u548c\u53c2\u6570\uff0c\u6211\u4eec\u8bf4\u8be5\u65b9\u6cd5\u88ab\u91cd\u5199 (Overriding)\u3002\u5b50\u7c7b\u7684\u5bf9\u8c61\u4f7f\u7528\u8fd9\u4e2a\u65b9\u6cd5\u65f6\uff0c\u5c06\u8c03\u7528\u5b50\u7c7b\u4e2d\u7684\u5b9a\u4e49\uff0c\u5bf9\u5b83\u800c\u8a00\uff0c\u7236\u7c7b\u4e2d\u7684\u5b9a\u4e49\u5982\u540c\u88ab"\u5c4f\u853d"\u4e86\u3002\u5982\u679c\u5728\u4e00\u4e2a\u7c7b\u4e2d\u5b9a\u4e49\u4e86\u591a\u4e2a\u540c\u540d\u7684\u65b9 \u6cd5\uff0c\u5b83\u4eec\u6216\u6709\u4e0d\u540c\u7684\u53c2\u6570\u4e2a\u6570\u6216\u6709\u4e0d\u540c\u7684\u53c2\u6570\u7c7b\u578b\uff0c\u5219\u79f0\u4e3a\u65b9\u6cd5\u7684\u91cd\u8f7d(Overloading)\u3002Overloaded\u7684\u65b9\u6cd5\u662f\u53ef\u4ee5\u6539\u53d8\u8fd4\u56de\u503c\u7684\u7c7b\u578b\u3002<\/p>\n

15\u3001error\u548cexception\u6709\u4ec0\u4e48\u533a\u522b?
\nerror \u8868\u793a\u6062\u590d\u4e0d\u662f\u4e0d\u53ef\u80fd\u4f46\u5f88\u56f0\u96be\u7684\u60c5\u51b5\u4e0b\u7684\u4e00\u79cd\u4e25\u91cd\u95ee\u9898\u3002\u6bd4\u5982\u8bf4\u5185\u5b58\u6ea2\u51fa\u3002\u4e0d\u53ef\u80fd\u6307\u671b\u7a0b\u5e8f\u80fd\u5904\u7406\u8fd9\u6837\u7684\u60c5\u51b5\u3002
\nexception \u8868\u793a\u4e00\u79cd\u8bbe\u8ba1\u6216\u5b9e\u73b0\u95ee\u9898\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5b83\u8868\u793a\u5982\u679c\u7a0b\u5e8f\u8fd0\u884c\u6b63\u5e38\uff0c\u4ece\u4e0d\u4f1a\u53d1\u751f\u7684\u60c5\u51b5\u3002<\/p>\n

16\u3001\u540c\u6b65\u548c\u5f02\u6b65\u6709\u4f55\u5f02\u540c\uff0c\u5728\u4ec0\u4e48\u60c5\u51b5\u4e0b\u5206\u522b\u4f7f\u7528\u4ed6\u4eec\uff1f\u4e3e\u4f8b\u8bf4\u660e\u3002
\n\u5982\u679c\u6570\u636e\u5c06\u5728\u7ebf\u7a0b\u95f4\u5171\u4eab\u3002\u4f8b\u5982\u6b63\u5728\u5199\u7684\u6570\u636e\u4ee5\u540e\u53ef\u80fd\u88ab\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u8bfb\u5230\uff0c\u6216\u8005\u6b63\u5728\u8bfb\u7684\u6570\u636e\u53ef\u80fd\u5df2\u7ecf\u88ab\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u5199\u8fc7\u4e86\uff0c\u90a3\u4e48\u8fd9\u4e9b\u6570\u636e\u5c31\u662f\u5171\u4eab\u6570\u636e\uff0c\u5fc5\u987b\u8fdb\u884c\u540c\u6b65\u5b58\u53d6\u3002
\n\u5f53\u5e94\u7528\u7a0b\u5e8f\u5728\u5bf9\u8c61\u4e0a\u8c03\u7528\u4e86\u4e00\u4e2a\u9700\u8981\u82b1\u8d39\u5f88\u957f\u65f6\u95f4\u6765\u6267\u884c\u7684\u65b9\u6cd5\uff0c\u5e76\u4e14\u4e0d\u5e0c\u671b\u8ba9\u7a0b\u5e8f\u7b49\u5f85\u65b9\u6cd5\u7684\u8fd4\u56de\u65f6\uff0c\u5c31\u5e94\u8be5\u4f7f\u7528\u5f02\u6b65\u7f16\u7a0b\uff0c\u5728\u5f88\u591a\u60c5\u51b5\u4e0b\u91c7\u7528\u5f02\u6b65\u9014\u5f84\u5f80\u5f80\u66f4\u6709\u6548\u7387\u3002<\/p>\n

17\u3001abstract class\u548cinterface\u6709\u4ec0\u4e48\u533a\u522b?
\n\u58f0 \u660e\u65b9\u6cd5\u7684\u5b58\u5728\u800c\u4e0d\u53bb\u5b9e\u73b0\u5b83\u7684\u7c7b\u88ab\u53eb\u505a\u62bd\u8c61\u7c7b\uff08abstract class\uff09\uff0c\u5b83\u7528\u4e8e\u8981\u521b\u5efa\u4e00\u4e2a\u4f53\u73b0\u67d0\u4e9b\u57fa\u672c\u884c\u4e3a\u7684\u7c7b\uff0c\u5e76\u4e3a\u8be5\u7c7b\u58f0\u660e\u65b9\u6cd5\uff0c\u4f46\u4e0d\u80fd\u5728\u8be5\u7c7b\u4e2d\u5b9e\u73b0\u8be5\u7c7b\u7684\u60c5\u51b5\u3002\u4e0d\u80fd\u521b\u5efaabstract \u7c7b\u7684\u5b9e\u4f8b\u3002\u7136\u800c\u53ef\u4ee5\u521b\u5efa\u4e00\u4e2a\u53d8\u91cf\uff0c\u5176\u7c7b\u578b\u662f\u4e00\u4e2a\u62bd\u8c61\u7c7b\uff0c\u5e76\u8ba9\u5b83\u6307\u5411\u5177\u4f53\u5b50\u7c7b\u7684\u4e00\u4e2a\u5b9e\u4f8b\u3002\u4e0d\u80fd\u6709\u62bd\u8c61\u6784\u9020\u51fd\u6570\u6216\u62bd\u8c61\u9759\u6001\u65b9\u6cd5\u3002Abstract \u7c7b\u7684\u5b50\u7c7b\u4e3a\u5b83\u4eec\u7236\u7c7b\u4e2d\u7684\u6240\u6709\u62bd\u8c61\u65b9\u6cd5\u63d0\u4f9b\u5b9e\u73b0\uff0c\u5426\u5219\u5b83\u4eec\u4e5f\u662f\u62bd\u8c61\u7c7b\u4e3a\u3002\u53d6\u800c\u4ee3\u4e4b\uff0c\u5728\u5b50\u7c7b\u4e2d\u5b9e\u73b0\u8be5\u65b9\u6cd5\u3002\u77e5\u9053\u5176\u884c\u4e3a\u7684\u5176\u5b83\u7c7b\u53ef\u4ee5\u5728\u7c7b\u4e2d\u5b9e\u73b0\u8fd9\u4e9b\u65b9\u6cd5\u3002
\n\u63a5 \u53e3\uff08interface\uff09\u662f\u62bd\u8c61\u7c7b\u7684\u53d8\u4f53\u3002\u5728\u63a5\u53e3\u4e2d\uff0c\u6240\u6709\u65b9\u6cd5\u90fd\u662f\u62bd\u8c61\u7684\u3002\u591a\u7ee7\u627f\u6027\u53ef\u901a\u8fc7\u5b9e\u73b0\u8fd9\u6837\u7684\u63a5\u53e3\u800c\u83b7\u5f97\u3002\u63a5\u53e3\u4e2d\u7684\u6240\u6709\u65b9\u6cd5\u90fd\u662f\u62bd\u8c61\u7684\uff0c\u6ca1\u6709\u4e00\u4e2a\u6709 \u7a0b\u5e8f\u4f53\u3002\u63a5\u53e3\u53ea\u53ef\u4ee5\u5b9a\u4e49static final\u6210\u5458\u53d8\u91cf\u3002\u63a5\u53e3\u7684\u5b9e\u73b0\u4e0e\u5b50\u7c7b\u76f8\u4f3c\uff0c\u9664\u4e86\u8be5\u5b9e\u73b0\u7c7b\u4e0d\u80fd\u4ece\u63a5\u53e3\u5b9a\u4e49\u4e2d\u7ee7\u627f\u884c\u4e3a\u3002\u5f53\u7c7b\u5b9e\u73b0\u7279\u6b8a\u63a5\u53e3\u65f6\uff0c\u5b83\u5b9a\u4e49\uff08\u5373\u5c06\u7a0b\u5e8f\u4f53\u7ed9\u4e88\uff09\u6240\u6709\u8fd9\u79cd\u63a5\u53e3\u7684\u65b9\u6cd5\u3002 \u7136\u540e\uff0c\u5b83\u53ef\u4ee5\u5728\u5b9e\u73b0\u4e86\u8be5\u63a5\u53e3\u7684\u7c7b\u7684\u4efb\u4f55\u5bf9\u8c61\u4e0a\u8c03\u7528\u63a5\u53e3\u7684\u65b9\u6cd5\u3002\u7531\u4e8e\u6709\u62bd\u8c61\u7c7b\uff0c\u5b83\u5141\u8bb8\u4f7f\u7528\u63a5\u53e3\u540d\u4f5c\u4e3a\u5f15\u7528\u53d8\u91cf\u7684\u7c7b\u578b\u3002\u901a\u5e38\u7684\u52a8\u6001\u8054\u7f16\u5c06\u751f\u6548\u3002\u5f15\u7528\u53ef\u4ee5\u8f6c\u6362\u5230 \u63a5\u53e3\u7c7b\u578b\u6216\u4ece\u63a5\u53e3\u7c7b\u578b\u8f6c\u6362\uff0cinstanceof \u8fd0\u7b97\u7b26\u53ef\u4ee5\u7528\u6765\u51b3\u5b9a\u67d0\u5bf9\u8c61\u7684\u7c7b\u662f\u5426\u5b9e\u73b0\u4e86\u63a5\u53e3\u3002<\/p>\n

18\u3001heap\u548cstack\u6709\u4ec0\u4e48\u533a\u522b\u3002
\n\u6808\u662f\u4e00\u79cd\u7ebf\u5f62\u96c6\u5408\uff0c\u5176\u6dfb\u52a0\u548c\u5220\u9664\u5143\u7d20\u7684\u64cd\u4f5c\u5e94\u5728\u540c\u4e00\u6bb5\u5b8c\u6210\u3002\u6808\u6309\u7167\u540e\u8fdb\u5148\u51fa\u7684\u65b9\u5f0f\u8fdb\u884c\u5904\u7406\u3002
\n\u5806\u662f\u6808\u7684\u4e00\u4e2a\u7ec4\u6210\u5143\u7d20<\/p>\n

19\u3001forward \u548credirect\u7684\u533a\u522b
\nforward\u662f\u670d\u52a1\u5668\u8bf7\u6c42\u8d44\u6e90\uff0c\u670d\u52a1\u5668\u76f4\u63a5\u8bbf\u95ee\u76ee\u6807\u5730\u5740\u7684URL\uff0c\u628a\u90a3\u4e2aURL\u7684\u54cd\u5e94\u5185\u5bb9\u8bfb\u53d6\u8fc7\u6765\uff0c\u7136\u540e\u628a\u8fd9\u4e9b\u5185\u5bb9\u518d\u53d1\u7ed9\u6d4f\u89c8\u5668\uff0c\u6d4f\u89c8\u5668\u6839\u672c\u4e0d\u77e5\u9053\u670d\u52a1\u5668\u53d1\u9001\u7684\u5185\u5bb9\u662f\u4ece\u54ea\u513f\u6765\u7684\uff0c\u6240\u4ee5\u5b83\u7684\u5730\u5740\u680f\u4e2d\u8fd8\u662f\u539f\u6765\u7684\u5730\u5740\u3002
\nredirect\u5c31\u662f\u670d\u52a1\u7aef\u6839\u636e\u903b\u8f91,\u53d1\u9001\u4e00\u4e2a\u72b6\u6001\u7801,\u544a\u8bc9\u6d4f\u89c8\u5668\u91cd\u65b0\u53bb\u8bf7\u6c42\u90a3\u4e2a\u5730\u5740\uff0c\u4e00\u822c\u6765\u8bf4\u6d4f\u89c8\u5668\u4f1a\u7528\u521a\u624d\u8bf7\u6c42\u7684\u6240\u6709\u53c2\u6570\u91cd\u65b0\u8bf7\u6c42\uff0c\u6240\u4ee5session,request\u53c2\u6570\u90fd\u53ef\u4ee5\u83b7\u53d6\u3002<\/p>\n

20\u3001EJB\u4e0eJAVA BEAN\u7684\u533a\u522b\uff1f
\nJava Bean \u662f\u53ef\u590d\u7528\u7684\u7ec4\u4ef6\uff0c\u5bf9Java Bean\u5e76\u6ca1\u6709\u4e25\u683c\u7684\u89c4\u8303\uff0c\u7406\u8bba\u4e0a\u8bb2\uff0c\u4efb\u4f55\u4e00\u4e2aJava\u7c7b\u90fd\u53ef\u4ee5\u662f\u4e00\u4e2aBean\u3002\u4f46\u901a\u5e38\u60c5\u51b5\u4e0b\uff0c\u7531\u4e8eJava Bean\u662f\u88ab\u5bb9\u5668\u6240\u521b\u5efa\uff08\u5982Tomcat\uff09\u7684\uff0c\u6240\u4ee5Java Bean\u5e94\u5177\u6709\u4e00\u4e2a\u65e0\u53c2\u7684\u6784\u9020\u5668\uff0c\u53e6\u5916\uff0c\u901a\u5e38Java Bean\u8fd8\u8981\u5b9e\u73b0Serializable\u63a5\u53e3\u7528\u4e8e\u5b9e\u73b0Bean\u7684\u6301\u4e45\u6027\u3002Java Bean\u5b9e\u9645\u4e0a\u76f8\u5f53\u4e8e\u5fae\u8f6fCOM\u6a21\u578b\u4e2d\u7684\u672c\u5730\u8fdb\u7a0b\u5185COM\u7ec4\u4ef6\uff0c\u5b83\u662f\u4e0d\u80fd\u88ab\u8de8\u8fdb\u7a0b\u8bbf\u95ee\u7684\u3002Enterprise Java Bean \u76f8\u5f53\u4e8eDCOM\uff0c\u5373\u5206\u5e03\u5f0f\u7ec4\u4ef6\u3002\u5b83\u662f\u57fa\u4e8eJava\u7684\u8fdc\u7a0b\u65b9\u6cd5\u8c03\u7528\uff08RMI\uff09\u6280\u672f\u7684\uff0c\u6240\u4ee5EJB\u53ef\u4ee5\u88ab\u8fdc\u7a0b\u8bbf\u95ee\uff08\u8de8\u8fdb\u7a0b\u3001\u8de8\u8ba1\u7b97\u673a\uff09\u3002\u4f46EJB\u5fc5\u987b\u88ab\u5e03\u7f72\u5728 \u8bf8\u5982Webspere\u3001WebLogic\u8fd9\u6837\u7684\u5bb9\u5668\u4e2d\uff0cEJB\u5ba2\u6237\u4ece\u4e0d\u76f4\u63a5\u8bbf\u95ee\u771f\u6b63\u7684EJB\u7ec4\u4ef6\uff0c\u800c\u662f\u901a\u8fc7\u5176\u5bb9\u5668\u8bbf\u95ee\u3002EJB\u5bb9\u5668\u662fEJB\u7ec4\u4ef6\u7684\u4ee3\u7406\uff0c EJB\u7ec4\u4ef6\u7531\u5bb9\u5668\u6240\u521b\u5efa\u548c\u7ba1\u7406\u3002\u5ba2\u6237\u901a\u8fc7\u5bb9\u5668\u6765\u8bbf\u95ee\u771f\u6b63\u7684EJB\u7ec4\u4ef6\u3002<\/p>\n

21\u3001Static Nested Class \u548c Inner Class\u7684\u4e0d\u540c\u3002
\nStatic Nested Class\u662f\u88ab\u58f0\u660e\u4e3a\u9759\u6001\uff08static\uff09\u7684\u5185\u90e8\u7c7b\uff0c\u5b83\u53ef\u4ee5\u4e0d\u4f9d\u8d56\u4e8e\u5916\u90e8\u7c7b\u5b9e\u4f8b\u88ab\u5b9e\u4f8b\u5316\u3002\u800c\u901a\u5e38\u7684\u5185\u90e8\u7c7b\u9700\u8981\u5728\u5916\u90e8\u7c7b\u5b9e\u4f8b\u5316\u540e\u624d\u80fd\u5b9e\u4f8b\u5316\u3002
\n22\u3001JSP\u4e2d\u52a8\u6001INCLUDE\u4e0e\u9759\u6001INCLUDE\u7684\u533a\u522b\uff1f
\n\u52a8\u6001INCLUDE\u7528jsp:include\u52a8\u4f5c\u5b9e\u73b0 \u5b83\u603b\u662f\u4f1a\u68c0\u67e5\u6240\u542b\u6587\u4ef6\u4e2d\u7684\u53d8\u5316\uff0c\u9002\u5408\u7528\u4e8e\u5305\u542b\u52a8\u6001\u9875\u9762\uff0c\u5e76\u4e14\u53ef\u4ee5\u5e26\u53c2\u6570\u3002
\n\u9759\u6001INCLUDE\u7528include\u4f2a\u7801\u5b9e\u73b0,\u5b9a\u4e0d\u4f1a\u68c0\u67e5\u6240\u542b\u6587\u4ef6\u7684\u53d8\u5316\uff0c\u9002\u7528\u4e8e\u5305\u542b\u9759\u6001\u9875\u9762<\/p>\n

23\u3001\u4ec0\u4e48\u65f6\u5019\u7528assert\u3002
\nassertion (\u65ad\u8a00)\u5728\u8f6f\u4ef6\u5f00\u53d1\u4e2d\u662f\u4e00\u79cd\u5e38\u7528\u7684\u8c03\u8bd5\u65b9\u5f0f\uff0c\u5f88\u591a\u5f00\u53d1\u8bed\u8a00\u4e2d\u90fd\u652f\u6301\u8fd9\u79cd\u673a\u5236\u3002\u5728\u5b9e\u73b0\u4e2d\uff0cassertion\u5c31\u662f\u5728\u7a0b\u5e8f\u4e2d\u7684\u4e00\u6761\u8bed\u53e5\uff0c\u5b83\u5bf9\u4e00\u4e2a boolean\u8868\u8fbe\u5f0f\u8fdb\u884c\u68c0\u67e5\uff0c\u4e00\u4e2a\u6b63\u786e\u7a0b\u5e8f\u5fc5\u987b\u4fdd\u8bc1\u8fd9\u4e2aboolean\u8868\u8fbe\u5f0f\u7684\u503c\u4e3atrue\uff1b\u5982\u679c\u8be5\u503c\u4e3afalse\uff0c\u8bf4\u660e\u7a0b\u5e8f\u5df2\u7ecf\u5904\u4e8e\u4e0d\u6b63\u786e\u7684\u72b6\u6001\u4e0b\uff0c \u7cfb\u7edf\u5c06\u7ed9\u51fa\u8b66\u544a\u6216\u9000\u51fa\u3002\u4e00\u822c\u6765\u8bf4\uff0cassertion\u7528\u4e8e\u4fdd\u8bc1\u7a0b\u5e8f\u6700\u57fa\u672c\u3001\u5173\u952e\u7684\u6b63\u786e\u6027\u3002assertion\u68c0\u67e5\u901a\u5e38\u5728\u5f00\u53d1\u548c\u6d4b\u8bd5\u65f6\u5f00\u542f\u3002\u4e3a\u4e86\u63d0\u9ad8\u6027\u80fd\uff0c \u5728\u8f6f\u4ef6\u53d1\u5e03\u540e\uff0cassertion\u68c0\u67e5\u901a\u5e38\u662f\u5173\u95ed\u7684\u3002<\/p>\n

24\u3001GC\u662f\u4ec0\u4e48? \u4e3a\u4ec0\u4e48\u8981\u6709GC?
\n\u3000 \u3000GC\u662f\u5783\u573e\u6536\u96c6\u7684\u610f\u601d\uff08Gabage Collection\uff09,\u5185\u5b58\u5904\u7406\u662f\u7f16\u7a0b\u4eba\u5458\u5bb9\u6613\u51fa\u73b0\u95ee\u9898\u7684\u5730\u65b9\uff0c\u5fd8\u8bb0\u6216\u8005\u9519\u8bef\u7684\u5185\u5b58\u56de\u6536\u4f1a\u5bfc\u81f4\u7a0b\u5e8f\u6216\u7cfb\u7edf\u7684\u4e0d\u7a33\u5b9a\u751a\u81f3\u5d29\u6e83\uff0cJava\u63d0\u4f9b\u7684GC\u529f\u80fd\u53ef\u4ee5 \u81ea\u52a8\u76d1\u6d4b\u5bf9\u8c61\u662f\u5426\u8d85\u8fc7\u4f5c\u7528\u57df\u4ece\u800c\u8fbe\u5230\u81ea\u52a8\u56de\u6536\u5185\u5b58\u7684\u76ee\u7684\uff0cJava\u8bed\u8a00\u6ca1\u6709\u63d0\u4f9b\u91ca\u653e\u5df2\u5206\u914d\u5185\u5b58\u7684\u663e\u793a\u64cd\u4f5c\u65b9\u6cd5\u3002<\/p>\n

25\u3001short s1 = 1; s1 = s1 + 1;\u6709\u4ec0\u4e48\u9519? short s1 = 1; s1 += 1;\u6709\u4ec0\u4e48\u9519?
\nshort s1 = 1; s1 = s1 + 1; \uff08s1+1\u8fd0\u7b97\u7ed3\u679c\u662fint\u578b\uff0c\u9700\u8981\u5f3a\u5236\u8f6c\u6362\u7c7b\u578b\uff09
\nshort s1 = 1; s1 += 1;\uff08\u53ef\u4ee5\u6b63\u786e\u7f16\u8bd1\uff09<\/p>\n

26\u3001Math.round(11.5)\u7b49\u65bc\u591a\u5c11? Math.round(-11.5)\u7b49\u65bc\u591a\u5c11?
\nMath.round(11.5)==12
\nMath.round(-11.5)==-11
\nround\u65b9\u6cd5\u8fd4\u56de\u4e0e\u53c2\u6570\u6700\u63a5\u8fd1\u7684\u957f\u6574\u6570\uff0c\u53c2\u6570\u52a01\/2\u540e\u6c42\u5176floor.<\/p>\n

27\u3001String s = new String("xyz");\u521b\u5efa\u4e86\u51e0\u4e2aString Object?
\n\u4e24\u4e2a<\/p>\n

28\u3001\u8bbe\u8ba14\u4e2a\u7ebf\u7a0b\uff0c\u5176\u4e2d\u4e24\u4e2a\u7ebf\u7a0b\u6bcf\u6b21\u5bf9j\u589e\u52a01\uff0c\u53e6\u5916\u4e24\u4e2a\u7ebf\u7a0b\u5bf9j\u6bcf\u6b21\u51cf\u5c111\u3002\u5199\u51fa\u7a0b\u5e8f\u3002
\n\u4ee5\u4e0b\u7a0b\u5e8f\u4f7f\u7528\u5185\u90e8\u7c7b\u5b9e\u73b0\u7ebf\u7a0b\uff0c\u5bf9j\u589e\u51cf\u7684\u65f6\u5019\u6ca1\u6709\u8003\u8651\u987a\u5e8f\u95ee\u9898\u3002
\npublic class ThreadTest1{
\nprivate int j;
\npublic static void main(String args[]){
\nThreadTest1 tt=new ThreadTest1();
\nInc inc=tt.new Inc();
\nDec dec=tt.new Dec();
\nfor(int i=0;i<2;i++){\nThread t=new Thread(inc);\nt.start();\nt=new Thread(dec);\nt.start();\n}\n}\nprivate synchronized void inc(){\nj++;\nSystem.out.println(Thread.currentThread().getName()+"-inc:"+j);\n}\nprivate synchronized void dec(){\nj--;\nSystem.out.println(Thread.currentThread().getName()+"-dec:"+j);\n}\nclass Inc implements Runnable{\npublic void run(){\nfor(int i=0;i<100;i++){\ninc();\n}\n}\n}\nclass Dec implements Runnable{\npublic void run(){\nfor(int i=0;i<100;i++){\ndec();\n}\n}\n}\n}\n\n29\u3001Java\u6709\u6ca1\u6709goto?\njava\u4e2d\u7684\u4fdd\u7559\u5b57\uff0c\u73b0\u5728\u6ca1\u6709\u5728java\u4e2d\u4f7f\u7528\u3002\n\n30\u3001\u542f\u52a8\u4e00\u4e2a\u7ebf\u7a0b\u662f\u7528run()\u8fd8\u662fstart()?\n\u542f\u52a8\u4e00\u4e2a\u7ebf\u7a0b\u662f\u8c03\u7528start()\u65b9\u6cd5\uff0c\u4f7f\u7ebf\u7a0b\u6240\u4ee3\u8868\u7684\u865a\u62df\u5904\u7406\u673a\u5904\u4e8e\u53ef\u8fd0\u884c\u72b6\u6001\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u53ef\u4ee5\u7531JVM\u8c03\u5ea6\u5e76\u6267\u884c\u3002\u8fd9\u5e76\u4e0d\u610f\u5473\u7740\u7ebf\u7a0b\u5c31\u4f1a\u7acb\u5373\u8fd0\u884c\u3002run()\u65b9\u6cd5\u53ef\u4ee5\u4ea7\u751f\u5fc5\u987b\u9000\u51fa\u7684\u6807\u5fd7\u6765\u505c\u6b62\u4e00\u4e2a\u7ebf\u7a0b\u3002\n\n31\u3001EJB\u5305\u62ec\uff08SessionBean,EntityBean\uff09\u8bf4\u51fa\u4ed6\u4eec\u7684\u751f\u547d\u5468\u671f\uff0c\u53ca\u5982\u4f55\u7ba1\u7406\u4e8b\u52a1\u7684\uff1f\nSessionBean\uff1a Stateless Session Bean \u7684\u751f\u547d\u5468\u671f\u662f\u7531\u5bb9\u5668\u51b3\u5b9a\u7684\uff0c\u5f53\u5ba2\u6237\u673a\u53d1\u51fa\u8bf7\u6c42\u8981\u5efa\u7acb\u4e00\u4e2aBean\u7684\u5b9e\u4f8b\u65f6\uff0cEJB\u5bb9\u5668\u4e0d\u4e00\u5b9a\u8981\u521b\u5efa\u4e00\u4e2a\u65b0\u7684Bean\u7684\u5b9e\u4f8b\u4f9b\u5ba2\u6237\u673a\u8c03\u7528\uff0c\u800c\u662f\u968f\u4fbf\u627e\u4e00\u4e2a\u73b0 \u6709\u7684\u5b9e\u4f8b\u63d0\u4f9b\u7ed9\u5ba2\u6237\u673a\u3002\u5f53\u5ba2\u6237\u673a\u7b2c\u4e00\u6b21\u8c03\u7528\u4e00\u4e2aStateful Session Bean \u65f6\uff0c\u5bb9\u5668\u5fc5\u987b\u7acb\u5373\u5728\u670d\u52a1\u5668\u4e2d\u521b\u5efa\u4e00\u4e2a\u65b0\u7684Bean\u5b9e\u4f8b\uff0c\u5e76\u5173\u8054\u5230\u5ba2\u6237\u673a\u4e0a\uff0c\u4ee5\u540e\u6b64\u5ba2\u6237\u673a\u8c03\u7528Stateful Session Bean \u7684\u65b9\u6cd5\u65f6\u5bb9\u5668\u4f1a\u628a\u8c03\u7528\u5206\u6d3e\u5230\u4e0e\u6b64\u5ba2\u6237\u673a\u76f8\u5173\u8054\u7684Bean\u5b9e\u4f8b\u3002\nEntityBean\uff1aEntity Beans\u80fd\u5b58\u6d3b\u76f8\u5bf9\u8f83\u957f\u7684\u65f6\u95f4\uff0c\u5e76\u4e14\u72b6\u6001\u662f\u6301\u7eed\u7684\u3002\u53ea\u8981\u6570\u636e\u5e93\u4e2d\u7684\u6570\u636e\u5b58\u5728\uff0cEntity beans\u5c31\u4e00\u76f4\u5b58\u6d3b\u3002\u800c\u4e0d\u662f\u6309\u7167\u5e94\u7528\u7a0b\u5e8f\u6216\u8005\u670d\u52a1\u8fdb\u7a0b\u6765\u8bf4\u7684\u3002\u5373\u4f7fEJB\u5bb9\u5668\u5d29\u6e83\u4e86\uff0cEntity beans\u4e5f\u662f\u5b58\u6d3b\u7684\u3002Entity Beans\u751f\u547d\u5468\u671f\u80fd\u591f\u88ab\u5bb9\u5668\u6216\u8005 Beans\u81ea\u5df1\u7ba1\u7406\u3002\nEJB\u901a\u8fc7\u4ee5\u4e0b\u6280\u672f\u7ba1\u7406\u5b9e\u52a1\uff1a\u5bf9\u8c61\u7ba1\u7406\u7ec4\u7ec7\uff08OMG\uff09\u7684\u5bf9\u8c61\u5b9e\u52a1\u670d\u52a1\uff08OTS\uff09\uff0cSun Microsystems\u7684Transaction Service\uff08JTS\uff09\u3001Java Transaction API\uff08JTA\uff09\uff0c\u5f00\u53d1\u7ec4\uff08X\/Open\uff09\u7684XA\u63a5\u53e3\u3002\n\n32\u3001\u5e94\u7528\u670d\u52a1\u5668\u6709\u90a3\u4e9b\uff1f\nBEA WebLogic Server\uff0cIBM WebSphere Application Server\uff0cOracle9i Application Server\uff0cjBoss\uff0cTomcat\n\n33\u3001\u7ed9\u6211\u4e00\u4e2a\u4f60\u6700\u5e38\u89c1\u5230\u7684runtime exception\u3002\nArithmeticException, ArrayStoreException, BufferOverflowException, BufferUnderflowException, CannotRedoException, CannotUndoException, ClassCastException, CMMException, ConcurrentModificationException, DOMException, EmptyStackException, IllegalArgumentException, IllegalMonitorStateException, IllegalPathStateException, IllegalStateException, ImagingOpException, IndexOutOfBoundsException, MissingResourceException, NegativeArraySizeException, NoSuchElementException, NullPointerException, ProfileDataException, ProviderException, RasterFormatException, SecurityException, SystemException, UndeclaredThrowableException, UnmodifiableSetException, UnsupportedOperationException\n\n34\u3001\u63a5\u53e3\u662f\u5426\u53ef\u7ee7\u627f\u63a5\u53e3? \u62bd\u8c61\u7c7b\u662f\u5426\u53ef\u5b9e\u73b0(implements)\u63a5\u53e3? \u62bd\u8c61\u7c7b\u662f\u5426\u53ef\u7ee7\u627f\u5b9e\u4f53\u7c7b(concrete class)?\n\u63a5\u53e3\u53ef\u4ee5\u7ee7\u627f\u63a5\u53e3\u3002\u62bd\u8c61\u7c7b\u53ef\u4ee5\u5b9e\u73b0(implements)\u63a5\u53e3\uff0c\u62bd\u8c61\u7c7b\u662f\u5426\u53ef\u7ee7\u627f\u5b9e\u4f53\u7c7b\uff0c\u4f46\u524d\u63d0\u662f\u5b9e\u4f53\u7c7b\u5fc5\u987b\u6709\u660e\u786e\u7684\u6784\u9020\u51fd\u6570\u3002\n\n35\u3001List, Set, Map\u662f\u5426\u7ee7\u627f\u81eaCollection\u63a5\u53e3?\nList\uff0cSet\u662f\uff0cMap\u4e0d\u662f\n\n36\u3001\u8bf4\u51fa\u6570\u636e\u8fde\u63a5\u6c60\u7684\u5de5\u4f5c\u673a\u5236\u662f\u4ec0\u4e48?\nJ2EE \u670d\u52a1\u5668\u542f\u52a8\u65f6\u4f1a\u5efa\u7acb\u4e00\u5b9a\u6570\u91cf\u7684\u6c60\u8fde\u63a5\uff0c\u5e76\u4e00\u76f4\u7ef4\u6301\u4e0d\u5c11\u4e8e\u6b64\u6570\u76ee\u7684\u6c60\u8fde\u63a5\u3002\u5ba2\u6237\u7aef\u7a0b\u5e8f\u9700\u8981\u8fde\u63a5\u65f6\uff0c\u6c60\u9a71\u52a8\u7a0b\u5e8f\u4f1a\u8fd4\u56de\u4e00\u4e2a\u672a\u4f7f\u7528\u7684\u6c60\u8fde\u63a5\u5e76\u5c06\u5176\u8868\u8bb0\u4e3a\u5fd9\u3002\u5982\u679c \u5f53\u524d\u6ca1\u6709\u7a7a\u95f2\u8fde\u63a5\uff0c\u6c60\u9a71\u52a8\u7a0b\u5e8f\u5c31\u65b0\u5efa\u4e00\u5b9a\u6570\u91cf\u7684\u8fde\u63a5\uff0c\u65b0\u5efa\u8fde\u63a5\u7684\u6570\u91cf\u6709\u914d\u7f6e\u53c2\u6570\u51b3\u5b9a\u3002\u5f53\u4f7f\u7528\u7684\u6c60\u8fde\u63a5\u8c03\u7528\u5b8c\u6210\u540e\uff0c\u6c60\u9a71\u52a8\u7a0b\u5e8f\u5c06\u6b64\u8fde\u63a5\u8868\u8bb0\u4e3a\u7a7a\u95f2\uff0c\u5176\u4ed6\u8c03\u7528 \u5c31\u53ef\u4ee5\u4f7f\u7528\u8fd9\u4e2a\u8fde\u63a5\u3002\n\n37\u3001abstract\u7684method\u662f\u5426\u53ef\u540c\u65f6\u662fstatic,\u662f\u5426\u53ef\u540c\u65f6\u662fnative\uff0c\u662f\u5426\u53ef\u540c\u65f6\u662fsynchronized?\n\u90fd\u4e0d\u80fd\n\n38\u3001\u6570\u7ec4\u6709\u6ca1\u6709length()\u8fd9\u4e2a\u65b9\u6cd5? String\u6709\u6ca1\u6709length()\u8fd9\u4e2a\u65b9\u6cd5\uff1f\n\u6570\u7ec4\u6ca1\u6709length()\u8fd9\u4e2a\u65b9\u6cd5\uff0c\u6709length\u7684\u5c5e\u6027\u3002String\u6709\u6709length()\u8fd9\u4e2a\u65b9\u6cd5\u3002\n\n39\u3001Set\u91cc\u7684\u5143\u7d20\u662f\u4e0d\u80fd\u91cd\u590d\u7684\uff0c\u90a3\u4e48\u7528\u4ec0\u4e48\u65b9\u6cd5\u6765\u533a\u5206\u91cd\u590d\u4e0e\u5426\u5462? \u662f\u7528==\u8fd8\u662fequals()? \u5b83\u4eec\u6709\u4f55\u533a\u522b?\nSet\u91cc\u7684\u5143\u7d20\u662f\u4e0d\u80fd\u91cd\u590d\u7684\uff0c\u90a3\u4e48\u7528iterator()\u65b9\u6cd5\u6765\u533a\u5206\u91cd\u590d\u4e0e\u5426\u3002equals()\u662f\u5224\u8bfb\u4e24\u4e2aSet\u662f\u5426\u76f8\u7b49\u3002\nequals()\u548c==\u65b9\u6cd5\u51b3\u5b9a\u5f15\u7528\u503c\u662f\u5426\u6307\u5411\u540c\u4e00\u5bf9\u8c61equals()\u5728\u7c7b\u4e2d\u88ab\u8986\u76d6\uff0c\u4e3a\u7684\u662f\u5f53\u4e24\u4e2a\u5206\u79bb\u7684\u5bf9\u8c61\u7684\u5185\u5bb9\u548c\u7c7b\u578b\u76f8\u914d\u7684\u8bdd\uff0c\u8fd4\u56de\u771f\u503c\u3002\n\n40\u3001\u6784\u9020\u5668Constructor\u662f\u5426\u53ef\u88aboverride?\n\u6784\u9020\u5668Constructor\u4e0d\u80fd\u88ab\u7ee7\u627f\uff0c\u56e0\u6b64\u4e0d\u80fd\u91cd\u5199Overriding\uff0c\u4f46\u53ef\u4ee5\u88ab\u91cd\u8f7dOverloading\u3002\n\n41\u3001\u662f\u5426\u53ef\u4ee5\u7ee7\u627fString\u7c7b?\nString\u7c7b\u662ffinal\u7c7b\u6545\u4e0d\u53ef\u4ee5\u7ee7\u627f\u3002\n\n42\u3001swtich\u662f\u5426\u80fd\u4f5c\u7528\u5728byte\u4e0a\uff0c\u662f\u5426\u80fd\u4f5c\u7528\u5728long\u4e0a\uff0c\u662f\u5426\u80fd\u4f5c\u7528\u5728String\u4e0a?\nswitch\uff08expr1\uff09\u4e2d\uff0cexpr1\u662f\u4e00\u4e2a\u6574\u6570\u8868\u8fbe\u5f0f\u3002\u56e0\u6b64\u4f20\u9012\u7ed9 switch \u548c case \u8bed\u53e5\u7684\u53c2\u6570\u5e94\u8be5\u662f int\u3001 short\u3001 char \u6216\u8005 byte\u3002long,string \u90fd\u4e0d\u80fd\u4f5c\u7528\u4e8eswtich\u3002\n\n43\u3001try {}\u91cc\u6709\u4e00\u4e2areturn\u8bed\u53e5\uff0c\u90a3\u4e48\u7d27\u8ddf\u5728\u8fd9\u4e2atry\u540e\u7684finally {}\u91cc\u7684code\u4f1a\u4e0d\u4f1a\u88ab\u6267\u884c\uff0c\u4ec0\u4e48\u65f6\u5019\u88ab\u6267\u884c\uff0c\u5728return\u524d\u8fd8\u662f\u540e?\n\u4f1a\u6267\u884c\uff0c\u5728return\u524d\u6267\u884c\u3002\n\n44\u3001\u7f16\u7a0b\u9898: \u7528\u6700\u6709\u6548\u7387\u7684\u65b9\u6cd5\u7b97\u51fa2\u4e58\u4ee58\u7b49\u65bc\u51e0?\n2 << 3\n\n45\u3001\u4e24\u4e2a\u5bf9\u8c61\u503c\u76f8\u540c(x.equals(y) == true)\uff0c\u4f46\u5374\u53ef\u6709\u4e0d\u540c\u7684hash code\uff0c\u8fd9\u53e5\u8bdd\u5bf9\u4e0d\u5bf9?\n\u4e0d\u5bf9\uff0c\u6709\u76f8\u540c\u7684hash code\u3002\n\n46\u3001\u5f53\u4e00\u4e2a\u5bf9\u8c61\u88ab\u5f53\u4f5c\u53c2\u6570\u4f20\u9012\u5230\u4e00\u4e2a\u65b9\u6cd5\u540e\uff0c\u6b64\u65b9\u6cd5\u53ef\u6539\u53d8\u8fd9\u4e2a\u5bf9\u8c61\u7684\u5c5e\u6027\uff0c\u5e76\u53ef\u8fd4\u56de\u53d8\u5316\u540e\u7684\u7ed3\u679c\uff0c\u90a3\u4e48\u8fd9\u91cc\u5230\u5e95\u662f\u503c\u4f20\u9012\u8fd8\u662f\u5f15\u7528\u4f20\u9012?\n\u662f\u503c\u4f20\u9012\u3002Java \u7f16\u7a0b\u8bed\u8a00\u53ea\u6709\u503c\u4f20\u9012\u53c2\u6570\u3002\u5f53\u4e00\u4e2a\u5bf9\u8c61\u5b9e\u4f8b\u4f5c\u4e3a\u4e00\u4e2a\u53c2\u6570\u88ab\u4f20\u9012\u5230\u65b9\u6cd5\u4e2d\u65f6\uff0c\u53c2\u6570\u7684\u503c\u5c31\u662f\u5bf9\u8be5\u5bf9\u8c61\u7684\u5f15\u7528\u3002\u5bf9\u8c61\u7684\u5185\u5bb9\u53ef\u4ee5\u5728\u88ab\u8c03\u7528\u7684\u65b9\u6cd5\u4e2d\u6539\u53d8\uff0c\u4f46\u5bf9\u8c61\u7684\u5f15\u7528\u662f\u6c38\u8fdc\u4e0d\u4f1a\u6539\u53d8\u7684\u3002\n\n47\u3001\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u8fdb\u5165\u4e00\u4e2a\u5bf9\u8c61\u7684\u4e00\u4e2asynchronized\u65b9\u6cd5\u540e\uff0c\u5176\u5b83\u7ebf\u7a0b\u662f\u5426\u53ef\u8fdb\u5165\u6b64\u5bf9\u8c61\u7684\u5176\u5b83\u65b9\u6cd5?\n\u4e0d\u80fd\uff0c\u4e00\u4e2a\u5bf9\u8c61\u7684\u4e00\u4e2asynchronized\u65b9\u6cd5\u53ea\u80fd\u7531\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95ee\u3002\n\n48\u3001\u7f16\u7a0b\u9898: \u5199\u4e00\u4e2aSingleton\u51fa\u6765\u3002\nSingleton\u6a21\u5f0f\u4e3b\u8981\u4f5c\u7528\u662f\u4fdd\u8bc1\u5728Java\u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0c\u4e00\u4e2a\u7c7bClass\u53ea\u6709\u4e00\u4e2a\u5b9e\u4f8b\u5b58\u5728\u3002\n\u4e00\u822cSingleton\u6a21\u5f0f\u901a\u5e38\u6709\u51e0\u79cd\u79cd\u5f62\u5f0f:\n\u7b2c\u4e00\u79cd\u5f62\u5f0f: \u5b9a\u4e49\u4e00\u4e2a\u7c7b\uff0c\u5b83\u7684\u6784\u9020\u51fd\u6570\u4e3aprivate\u7684\uff0c\u5b83\u6709\u4e00\u4e2astatic\u7684private\u7684\u8be5\u7c7b\u53d8\u91cf\uff0c\u5728\u7c7b\u521d\u59cb\u5316\u65f6\u5b9e\u4f8b\u8bdd\uff0c\u901a\u8fc7\u4e00\u4e2apublic\u7684getInstance\u65b9\u6cd5\u83b7\u53d6\u5bf9\u5b83\u7684\u5f15\u7528,\u7ee7\u800c\u8c03\u7528\u5176\u4e2d\u7684\u65b9\u6cd5\u3002\npublic class Singleton {\nprivate Singleton(){}\n\u3000\u3000 \/\/\u5728\u81ea\u5df1\u5185\u90e8\u5b9a\u4e49\u81ea\u5df1\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u662f\u4e0d\u662f\u5f88\u5947\u602a\uff1f\n\u3000\u3000 \/\/\u6ce8\u610f\u8fd9\u662fprivate \u53ea\u4f9b\u5185\u90e8\u8c03\u7528\n\u3000\u3000 private static Singleton instance = new Singleton();\n\u3000\u3000 \/\/\u8fd9\u91cc\u63d0\u4f9b\u4e86\u4e00\u4e2a\u4f9b\u5916\u90e8\u8bbf\u95ee\u672cclass\u7684\u9759\u6001\u65b9\u6cd5\uff0c\u53ef\u4ee5\u76f4\u63a5\u8bbf\u95ee\u3000\u3000\n\u3000\u3000 public static Singleton getInstance() {\n\u3000\u3000\u3000\u3000 return instance; \u3000\u3000\n\u3000\u3000 }\n}\n\u7b2c\u4e8c\u79cd\u5f62\u5f0f:\npublic class Singleton {\n\u3000\u3000private static Singleton instance = null;\n\u3000\u3000public static synchronized Singleton getInstance() {\n\u3000\u3000\/\/\u8fd9\u4e2a\u65b9\u6cd5\u6bd4\u4e0a\u9762\u6709\u6240\u6539\u8fdb\uff0c\u4e0d\u7528\u6bcf\u6b21\u90fd\u8fdb\u884c\u751f\u6210\u5bf9\u8c61\uff0c\u53ea\u662f\u7b2c\u4e00\u6b21\u3000\u3000\u3000 \u3000\n\u3000\u3000\/\/\u4f7f\u7528\u65f6\u751f\u6210\u5b9e\u4f8b\uff0c\u63d0\u9ad8\u4e86\u6548\u7387\uff01\n\u3000\u3000if (instance==null)\n\u3000\u3000\u3000\u3000instance\uff1dnew Singleton();\nreturn instance; \u3000\u3000}\n}\n\u5176\u4ed6\u5f62\u5f0f:\n\u5b9a\u4e49\u4e00\u4e2a\u7c7b\uff0c\u5b83\u7684\u6784\u9020\u51fd\u6570\u4e3aprivate\u7684\uff0c\u6240\u6709\u65b9\u6cd5\u4e3astatic\u7684\u3002\n\u4e00\u822c\u8ba4\u4e3a\u7b2c\u4e00\u79cd\u5f62\u5f0f\u8981\u66f4\u52a0\u5b89\u5168\u4e9b\n\n49\u3001Java\u7684\u63a5\u53e3\u548cC++\u7684\u865a\u7c7b\u7684\u76f8\u540c\u548c\u4e0d\u540c\u5904\u3002\n\u7531 \u4e8eJava\u4e0d\u652f\u6301\u591a\u7ee7\u627f\uff0c\u800c\u6709\u53ef\u80fd\u67d0\u4e2a\u7c7b\u6216\u5bf9\u8c61\u8981\u4f7f\u7528\u5206\u522b\u5728\u51e0\u4e2a\u7c7b\u6216\u5bf9\u8c61\u91cc\u9762\u7684\u65b9\u6cd5\u6216\u5c5e\u6027\uff0c\u73b0\u6709\u7684\u5355\u7ee7\u627f\u673a\u5236\u5c31\u4e0d\u80fd\u6ee1\u8db3\u8981\u6c42\u3002\u4e0e\u7ee7\u627f\u76f8\u6bd4\uff0c\u63a5\u53e3\u6709\u66f4\u9ad8\u7684\u7075 \u6d3b\u6027\uff0c\u56e0\u4e3a\u63a5\u53e3\u4e2d\u6ca1\u6709\u4efb\u4f55\u5b9e\u73b0\u4ee3\u7801\u3002\u5f53\u4e00\u4e2a\u7c7b\u5b9e\u73b0\u4e86\u63a5\u53e3\u4ee5\u540e\uff0c\u8be5\u7c7b\u8981\u5b9e\u73b0\u63a5\u53e3\u91cc\u9762\u6240\u6709\u7684\u65b9\u6cd5\u548c\u5c5e\u6027\uff0c\u5e76\u4e14\u63a5\u53e3\u91cc\u9762\u7684\u5c5e\u6027\u5728\u9ed8\u8ba4\u72b6\u6001\u4e0b\u9762\u90fd\u662fpublic static,\u6240\u6709\u65b9\u6cd5\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u662fpublic.\u4e00\u4e2a\u7c7b\u53ef\u4ee5\u5b9e\u73b0\u591a\u4e2a\u63a5\u53e3\u3002\n\n50\u3001Java\u4e2d\u7684\u5f02\u5e38\u5904\u7406\u673a\u5236\u7684\u7b80\u5355\u539f\u7406\u548c\u5e94\u7528\u3002\n\u5f53JAVA \u7a0b\u5e8f\u8fdd\u53cd\u4e86JAVA\u7684\u8bed\u4e49\u89c4\u5219\u65f6\uff0cJAVA\u865a\u62df\u673a\u5c31\u4f1a\u5c06\u53d1\u751f\u7684\u9519\u8bef\u8868\u793a\u4e3a\u4e00\u4e2a\u5f02\u5e38\u3002\u8fdd\u53cd\u8bed\u4e49\u89c4\u5219\u5305\u62ec2\u79cd\u60c5\u51b5\u3002\u4e00\u79cd\u662fJAVA\u7c7b\u5e93\u5185\u7f6e\u7684\u8bed\u4e49\u68c0\u67e5\u3002\u4f8b\u5982\u6570 \u7ec4\u4e0b\u6807\u8d8a\u754c,\u4f1a\u5f15\u53d1IndexOutOfBoundsException;\u8bbf\u95eenull\u7684\u5bf9\u8c61\u65f6\u4f1a\u5f15\u53d1NullPointerException\u3002\u53e6\u4e00\u79cd \u60c5\u51b5\u5c31\u662fJAVA\u5141\u8bb8\u7a0b\u5e8f\u5458\u6269\u5c55\u8fd9\u79cd\u8bed\u4e49\u68c0\u67e5\uff0c\u7a0b\u5e8f\u5458\u53ef\u4ee5\u521b\u5efa\u81ea\u5df1\u7684\u5f02\u5e38\uff0c\u5e76\u81ea\u7531\u9009\u62e9\u5728\u4f55\u65f6\u7528throw\u5173\u952e\u5b57\u5f15\u53d1\u5f02\u5e38\u3002\u6240\u6709\u7684\u5f02\u5e38\u90fd\u662f java.lang.Thowable\u7684\u5b50\u7c7b\u3002\n\n51\u3001\u5783\u573e\u56de\u6536\u7684\u4f18\u70b9\u548c\u539f\u7406\u3002\u5e76\u8003\u86512\u79cd\u56de\u6536\u673a\u5236\u3002\nJava \u8bed\u8a00\u4e2d\u4e00\u4e2a\u663e\u8457\u7684\u7279\u70b9\u5c31\u662f\u5f15\u5165\u4e86\u5783\u573e\u56de\u6536\u673a\u5236\uff0c\u4f7fc++\u7a0b\u5e8f\u5458\u6700\u5934\u75bc\u7684\u5185\u5b58\u7ba1\u7406\u7684\u95ee\u9898\u8fce\u5203\u800c\u89e3\uff0c\u5b83\u4f7f\u5f97Java\u7a0b\u5e8f\u5458\u5728\u7f16\u5199\u7a0b\u5e8f\u7684\u65f6\u5019\u4e0d\u518d\u9700\u8981\u8003\u8651\u5185\u5b58\u7ba1 \u7406\u3002\u7531\u4e8e\u6709\u4e2a\u5783\u573e\u56de\u6536\u673a\u5236\uff0cJava\u4e2d\u7684\u5bf9\u8c61\u4e0d\u518d\u6709"\u4f5c\u7528\u57df"\u7684\u6982\u5ff5\uff0c\u53ea\u6709\u5bf9\u8c61\u7684\u5f15\u7528\u624d\u6709"\u4f5c\u7528\u57df"\u3002\u5783\u573e\u56de\u6536\u53ef\u4ee5\u6709\u6548\u7684\u9632\u6b62\u5185\u5b58\u6cc4\u9732\uff0c\u6709\u6548\u7684\u4f7f\u7528\u53ef\u4ee5\u4f7f \u7528\u7684\u5185\u5b58\u3002\u5783\u573e\u56de\u6536\u5668\u901a\u5e38\u662f\u4f5c\u4e3a\u4e00\u4e2a\u5355\u72ec\u7684\u4f4e\u7ea7\u522b\u7684\u7ebf\u7a0b\u8fd0\u884c\uff0c\u4e0d\u53ef\u9884\u77e5\u7684\u60c5\u51b5\u4e0b\u5bf9\u5185\u5b58\u5806\u4e2d\u5df2\u7ecf\u6b7b\u4ea1\u7684\u6216\u8005\u957f\u65f6\u95f4\u6ca1\u6709\u4f7f\u7528\u7684\u5bf9\u8c61\u8fdb\u884c\u6e05\u695a\u548c\u56de\u6536\uff0c\u7a0b\u5e8f\u5458\u4e0d\u80fd \u5b9e\u65f6\u7684\u8c03\u7528\u5783\u573e\u56de\u6536\u5668\u5bf9\u67d0\u4e2a\u5bf9\u8c61\u6216\u6240\u6709\u5bf9\u8c61\u8fdb\u884c\u5783\u573e\u56de\u6536\u3002\u56de\u6536\u673a\u5236\u6709\u5206\u4ee3\u590d\u5236\u5783\u573e\u56de\u6536\u548c\u6807\u8bb0\u5783\u573e\u56de\u6536\uff0c\u589e\u91cf\u5783\u573e\u56de\u6536\u3002\n\n52\u3001\u8bf7\u8bf4\u51fa\u4f60\u6240\u77e5\u9053\u7684\u7ebf\u7a0b\u540c\u6b65\u7684\u65b9\u6cd5\u3002\nwait():\u4f7f\u4e00\u4e2a\u7ebf\u7a0b\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\uff0c\u5e76\u4e14\u91ca\u653e\u6240\u6301\u6709\u7684\u5bf9\u8c61\u7684lock\u3002\nsleep():\u4f7f\u4e00\u4e2a\u6b63\u5728\u8fd0\u884c\u7684\u7ebf\u7a0b\u5904\u4e8e\u7761\u7720\u72b6\u6001\uff0c\u662f\u4e00\u4e2a\u9759\u6001\u65b9\u6cd5\uff0c\u8c03\u7528\u6b64\u65b9\u6cd5\u8981\u6355\u6349InterruptedException\u5f02\u5e38\u3002\nnotify():\u5524\u9192\u4e00\u4e2a\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\u7684\u7ebf\u7a0b\uff0c\u6ce8\u610f\u7684\u662f\u5728\u8c03\u7528\u6b64\u65b9\u6cd5\u7684\u65f6\u5019\uff0c\u5e76\u4e0d\u80fd\u786e\u5207\u7684\u5524\u9192\u67d0\u4e00\u4e2a\u7b49\u5f85\u72b6\u6001\u7684\u7ebf\u7a0b\uff0c\u800c\u662f\u7531JVM\u786e\u5b9a\u5524\u9192\u54ea\u4e2a\u7ebf\u7a0b\uff0c\u800c\u4e14\u4e0d\u662f\u6309\u4f18\u5148\u7ea7\u3002\nAllnotity():\u5524\u9192\u6240\u6709\u5904\u5165\u7b49\u5f85\u72b6\u6001\u7684\u7ebf\u7a0b\uff0c\u6ce8\u610f\u5e76\u4e0d\u662f\u7ed9\u6240\u6709\u5524\u9192\u7ebf\u7a0b\u4e00\u4e2a\u5bf9\u8c61\u7684\u9501\uff0c\u800c\u662f\u8ba9\u5b83\u4eec\u7ade\u4e89\u3002\n\n53\u3001\u4f60\u6240\u77e5\u9053\u7684\u96c6\u5408\u7c7b\u90fd\u6709\u54ea\u4e9b\uff1f\u4e3b\u8981\u65b9\u6cd5\uff1f\n\u6700\u5e38\u7528\u7684\u96c6\u5408\u7c7b\u662f List \u548c Map\u3002 List \u7684\u5177\u4f53\u5b9e\u73b0\u5305\u62ec ArrayList \u548c Vector\uff0c\u5b83\u4eec\u662f\u53ef\u53d8\u5927\u5c0f\u7684\u5217\u8868\uff0c\u6bd4\u8f83\u9002\u5408\u6784\u5efa\u3001\u5b58\u50a8\u548c\u64cd\u4f5c\u4efb\u4f55\u7c7b\u578b\u5bf9\u8c61\u7684\u5143\u7d20\u5217\u8868\u3002 List \u9002\u7528\u4e8e\u6309\u6570\u503c\u7d22\u5f15\u8bbf\u95ee\u5143\u7d20\u7684\u60c5\u5f62\u3002\nMap \u63d0\u4f9b\u4e86\u4e00\u4e2a\u66f4\u901a\u7528\u7684\u5143\u7d20\u5b58\u50a8\u65b9\u6cd5\u3002 Map \u96c6\u5408\u7c7b\u7528\u4e8e\u5b58\u50a8\u5143\u7d20\u5bf9\uff08\u79f0\u4f5c"\u952e"\u548c"\u503c"\uff09\uff0c\u5176\u4e2d\u6bcf\u4e2a\u952e\u6620\u5c04\u5230\u4e00\u4e2a\u503c\u3002\n\n54\u3001\u63cf\u8ff0\u4e00\u4e0bJVM\u52a0\u8f7dclass\u6587\u4ef6\u7684\u539f\u7406\u673a\u5236?\nJVM\u4e2d\u7c7b\u7684\u88c5\u8f7d\u662f\u7531ClassLoader\u548c\u5b83\u7684\u5b50\u7c7b\u6765\u5b9e\u73b0\u7684,Java ClassLoader \u662f\u4e00\u4e2a\u91cd\u8981\u7684Java\u8fd0\u884c\u65f6\u7cfb\u7edf\u7ec4\u4ef6\u3002\u5b83\u8d1f\u8d23\u5728\u8fd0\u884c\u65f6\u67e5\u627e\u548c\u88c5\u5165\u7c7b\u6587\u4ef6\u7684\u7c7b\u3002\n\n55\u3001char\u578b\u53d8\u91cf\u4e2d\u80fd\u4e0d\u80fd\u5b58\u8d2e\u4e00\u4e2a\u4e2d\u6587\u6c49\u5b57?\u4e3a\u4ec0\u4e48?\n\u80fd\u591f\u5b9a\u4e49\u6210\u4e3a\u4e00\u4e2a\u4e2d\u6587\u7684\uff0c\u56e0\u4e3ajava\u4e2d\u4ee5unicode\u7f16\u7801\uff0c\u4e00\u4e2achar\u536016\u4e2a\u5b57\u8282\uff0c\u6240\u4ee5\u653e\u4e00\u4e2a\u4e2d\u6587\u662f\u6ca1\u95ee\u9898\u7684\n\n56\u3001\u591a\u7ebf\u7a0b\u6709\u51e0\u79cd\u5b9e\u73b0\u65b9\u6cd5,\u90fd\u662f\u4ec0\u4e48?\u540c\u6b65\u6709\u51e0\u79cd\u5b9e\u73b0\u65b9\u6cd5,\u90fd\u662f\u4ec0\u4e48?\n\u591a\u7ebf\u7a0b\u6709\u4e24\u79cd\u5b9e\u73b0\u65b9\u6cd5\uff0c\u5206\u522b\u662f\u7ee7\u627fThread\u7c7b\u4e0e\u5b9e\u73b0Runnable\u63a5\u53e3\n\u540c\u6b65\u7684\u5b9e\u73b0\u65b9\u9762\u6709\u4e24\u79cd\uff0c\u5206\u522b\u662fsynchronized,wait\u4e0enotify\n\n57\u3001JSP\u7684\u5185\u7f6e\u5bf9\u8c61\u53ca\u65b9\u6cd5\u3002\nrequest\u8868\u793aHttpServletRequest\u5bf9\u8c61\u3002\u5b83\u5305\u542b\u4e86\u6709\u5173\u6d4f\u89c8\u5668\u8bf7\u6c42\u7684\u4fe1\u606f\uff0c\u5e76\u4e14\u63d0\u4f9b\u4e86\u51e0\u4e2a\u7528\u4e8e\u83b7\u53d6cookie, 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