{"id":2419,"date":"2020-10-25T10:38:28","date_gmt":"2020-10-25T02:38:28","guid":{"rendered":"http:\/\/admin.evshou.com\/?p=2419"},"modified":"2020-10-26T14:31:36","modified_gmt":"2020-10-26T06:31:36","slug":"2020javaweb%e6%95%99%e7%a8%8b%ef%bc%9aservlet%e7%8a%b6%e6%80%81%e7%ae%a1%e7%90%86","status":"publish","type":"post","link":"https:\/\/www.9713job.com\/?p=2419","title":{"rendered":"2020Javaweb\u6559\u7a0b\uff1aservlet\u72b6\u6001\u7ba1\u7406"},"content":{"rendered":"

Javaweb\u6559\u7a0b\uff1aservlet\u72b6\u6001\u7ba1\u7406<\/h3>\n

servlet\u72b6\u6001\u7ba1\u7406<\/span><\/strong><\/p>\n

servlet\u751f\u547d\u5468\u671f<\/span><\/strong><\/p>\n

\u9636\u6bb5\u4e00\uff1a\u5b9e\u4f8b\u5316(\u8c03\u7528\u6784\u9020\u65b9\u6cd5)<\/span>
\n\u5b9e\u4f8b\u5316\u9636\u6bb5\u662fservlet\u751f\u547d\u5468\u671f\u4e2d\u7684\u7b2c\u4e00\u6b65\uff0c\u7531servlet\u5bb9\u5668\u8c03\u7528
\nservlet\u7684\u6784\u9020\u5668\u521b\u5efa\u4e00\u4e2a\u5177\u4f53\u7684servlet\u5bf9\u8c61\u7684\u8fc7\u7a0b\u3002<\/p>\n

\u9636\u6bb5\u4e8c\uff1a\u521d\u59cb\u5316(init\u65b9\u6cd5)<\/span>
\nservlet\u5728\u88ab\u52a0\u8f7d\u5b9e\u4f8b\u5316\u4e4b\u540e\uff0c\u5fc5\u987b\u8981\u521d\u59cb\u5316\u5b83\u3002\u5728\u521d\u59cb\u9636\u6bb5\uff0cinit()\u65b9\u6cd5\u4f1a\u88ab\u8c03\u7528<\/p>\n

\u9636\u6bb5\u4e09\uff1a\u5c31\u7eea\/\u670d\u52a1<\/span>
\nservlet\u88ab\u521d\u59cb\u5316\u4ee5\u540e\u5c31\u5904\u4e8e\u80fd\u591f\u54cd\u5e94\u8bf7\u6c42\u7684\u5c31\u7eea\u72b6\u6001\u3002<\/p>\n

\u9636\u6bb5\u56db\uff1a\u9500\u6bc1<\/span>
\nservlet\u5bb9\u5668\u5728\u9500\u6bc1servlet\u5bf9\u8c61\u65f6\u4f1a\u8c03\u7528destroy\u65b9\u6cd5\u6765\u91ca\u653e\u8d44\u6e90\u3002<\/p>\n

====================================
\nservlet\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898<\/span><\/strong><\/p>\n

\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898<\/span>
\n\u56e0\u4e3a\u6bcf\u6b21\u8bf7\u6c42\u90fd\u4f1a\u521b\u5efa\u4e00\u4e2a\u7ebf\u7a0b\uff0c\u5982\u679c\u591a\u4eba\u540c\u65f6\u8bf7\u6c42\uff0c\u90a3\u4e48\u5c31\u4f1a\u5b58\u5728\u591a\u4e2a\u7ebf\u7a0b
\n\u64cd\u4f5c\u540c\u4e00\u4e2aservlet\u5bf9\u8c61\uff0c\u90a3\u4e48\u5982\u679c\u5728\u5bf9\u5e94\u7684\u65b9\u6cd5\u4e2d\u64cd\u4f5c\u4e86\u6210\u5458\u53d8\u91cf\uff0c\u5c31\u6709\u53ef\u80fd
\n\u4ea7\u751f\u7ebf\u7a0b\u5b89\u5168\u7684\u95ee\u9898<\/p>\n

\u5982\u4f55\u4fdd\u8bc1\u7ebf\u7a0b\u5b89\u5168<\/span>
\n1.synchronize<\/span>
\n\u5c06\u5b58\u5728\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\u7684\u4ee3\u7801\u653e\u5230\u540c\u6b65\u4ee3\u7801\u5757\u4e2d
\n2.\u5b9e\u73b0SingleThreadModel<\/span>\u63a5\u53e3(\u5df2\u8fc7\u65f6)<\/span>
\nservlet\u5b9e\u73b0singleThreadModel\u63a5\u53e3\u540e\uff0c\u6bcf\u4e2a\u7ebf\u7a0b\u90fd\u4f1a\u521b\u5efaservlet\u5b9e\u4f8b
\n3.\u5c3d\u53ef\u80fd\u53ea\u4f7f\u7528\u5c40\u90e8\u53d8\u91cf<\/span><\/p>\n

\"\"
\n====================================
\nservlet\u521d\u59cb\u5316\u53c2\u6570<\/span><\/strong><\/p>\n

web.xml\u65b9\u5f0f<\/p>\n

<init-param>
\n<param-name>name<\/param-name>
\n<param-value>\u5f20\u4e09<\/param-value>
\n<\/init-param><\/p>\n

1.init-param\u5143\u7d20\u7528\u6765\u5b9a\u4e49servlet\u542f\u52a8\u7684\u53c2\u6570\uff0c\u53ef\u4ee5\u5b9a\u4e49\u591a\u4e2a
\n2.param-name\u8868\u793a\u53c2\u6570\u540d\u79f0
\n3.param-value\u8868\u793a\u53c2\u6570\u503c<\/p>\n

\u6ce8\u89e3\u65b9\u5f0f<\/span><\/p>\n

@WebServlet(name = \"initServlet\",value = \"\/is\",\r\n        initParams = {@WebInitParam(name = \"username\", value = \"zhangsan\"),\r\n                @WebInitParam(name = \"password\",value = \"123456\")})<\/pre>\n
dopost()\u65b9\u6cd5\u91cc\u6dfb\u52a0
\nServletConfig sc=this.getServletConfig();
\nString uname=sc.getInitParameter(“uname”);
\nString password=sc.getInitParameter(“password”);
\nsout(uname+”:”+password);<\/p>\n
====================================
\n\u72b6\u6001\u6982\u5ff5\u4ee5\u53cacookie\u57fa\u7840<\/span><\/strong><\/p>\n
\u72b6\u6001\u7ba1\u7406\u6982\u8ff0<\/span><\/strong><\/p>\n
\u4e3a\u4ec0\u4e48\u9700\u8981\u72b6\u6001\u7ba1\u7406<\/span>
\nHTTP\u534f\u8bae\u662f\u65e0\u72b6\u6001\u7684\uff0c\u4e0d\u80fd\u4fdd\u5b58\u6bcf\u6b21\u63d0\u4ea4\u7684\u4fe1\u606f\uff0c\u5373\u5f53\u670d\u52a1\u5668\u8fd4\u56de\u4e0e\u8bf7\u6c42\u76f8\u5bf9\u5e94\u7684\u5e94\u7b54\u4e4b\u540e\uff0c
\n\u8fd9\u6b21\u4e8b\u52a1\u7684\u6240\u6709\u4fe1\u606f\u5c31\u4e22\u6389\u4e86\u3002<\/p>\n
\u4ec0\u4e48\u662f\u72b6\u6001\u7ba1\u7406<\/span><\/p>\n
web\u5e94\u7528\u4e2d\u7684\u4f1a\u8bdd\u662f\u6307\u4e00\u4e2a\u5ba2\u6237\u7aef\u6d4f\u89c8\u5668\u4e0eweb\u670d\u52a1\u5668\u4e4b\u95f4\u8fde\u7eed\u53d1\u751f\u7684\u4e00\u7cfb\u5217\u8bf7\u6c42\u548c\u54cd\u5e94\u8fc7\u7a0b\u3002<\/p>\n
\u72b6\u6001\u7ba1\u7406\u7684\u4e24\u79cd\u6a21\u5f0f<\/span>
\n1.\u5ba2\u6237\u7aef\u72b6\u6001\u7ba1\u7406\u6280\u672f\uff1a\u5c06\u72b6\u6001\u4fdd\u5b58\u5728\u5ba2\u6237\u7aef\u3002\u4ee3\u8868\u6027\u7684\u662fcookie\u6280\u672f
\n2.\u670d\u52a1\u5668\u72b6\u6001\u7ba1\u7406\u6280\u672f\uff1a\u5c06\u72b6\u6001\u4fdd\u5b58\u5728\u670d\u52a1\u5668\u7aef\u3002\u4ee3\u8868\u6027\u7684\u662fsession\u6280\u672f(\u670d\u52a1\u5668\u4f20\u9012sessionID\u65f6\u9700\u8981\u4f7f\u7528cookie\u7684\u65b9\u5f0f)<\/p>\n
\u4ec0\u4e48\u662fcookie<\/span><\/p>\n
Cookie\u662f\u5728\u6d4f\u89c8\u5668\u8bbf\u95eeWEB\u670d\u52a1\u5668\u7684\u67d0\u4e2a\u8d44\u6e90\u65f6\uff0c\u7531WEB\u670d\u52a1\u5668\u5728HTTP\u54cd\u5e94\u6d88\u606f\u5934\u4e2d\u9644\u5e26\u4f20\u9001\u7ed9\u6d4f\u89c8\u5668\u7684\u4e00\u5c0f\u6bb5\u6570\u636e\uff0c
\nWEB\u670d\u52a1\u5668\u4f20\u9001\u7ed9\u5404\u4e2a\u5ba2\u6237\u7aef\u6d4f\u89c8\u5668\u7684\u6570\u636e\u662f\u53ef\u4ee5\u5404\u4e0d\u76f8\u540c\u7684\u3002
\n\u4e00\u65e6WEB\u6d4f\u89c8\u5668\u4fdd\u5b58\u4e86\u67d0\u4e2aCookie\uff0c\u90a3\u4e48\u5b83\u5728\u4ee5\u540e\u6bcf\u6b21\u8bbf\u95ee\u8be5WEB\u670d\u52a1\u5668\u65f6\uff0c\u90fd\u5e94\u5728HTTP\u8bf7\u6c42\u5934\u4e2d\u5c06\u8fd9\u4e2aCookie\u56de\u4f20\u7ed9WEB\u670d\u52a1\u5668\u3002
\nWEB\u670d\u52a1\u5668\u901a\u8fc7\u5728HTTP\u54cd\u5e94\u6d88\u606f\u4e2d\u589e\u52a0Set-Cookie\u54cd\u5e94\u5934\u5b57\u6bb5\u5c06Cookie\u4fe1\u606f\u53d1\u9001\u7ed9\u6d4f\u89c8\u5668\uff0c\u6d4f\u89c8\u5668\u5219\u901a\u8fc7\u5728HTTP\u8bf7\u6c42\u6d88\u606f\u4e2d
\n\u589e\u52a0Cookie\u8bf7\u6c42\u5934\u5b57\u6bb5\u5c06Cookie\u56de\u4f20\u7ed9WEB\u670d\u52a1\u5668\u3002
\n\u4e00\u4e2aCookie\u53ea\u80fd\u6807\u8bc6\u4e00\u79cd\u4fe1\u606f\uff0c\u5b83\u81f3\u5c11\u542b\u6709\u4e00\u4e2a\u6807\u8bc6\u8be5\u4fe1\u606f\u7684\u540d\u79f0\uff08NAME\uff09\u548c\u8bbe\u7f6e\u503c\uff08VALUE\uff09\u3002
\n\u4e00\u4e2aWEB\u7ad9\u70b9\u53ef\u4ee5\u7ed9\u4e00\u4e2aWEB\u6d4f\u89c8\u5668\u53d1\u9001\u591a\u4e2aCookie\uff0c\u4e00\u4e2aWEB\u6d4f\u89c8\u5668\u4e5f\u53ef\u4ee5\u5b58\u50a8\u591a\u4e2aWEB\u7ad9\u70b9\u63d0\u4f9b\u7684Cookie.
\n\u6d4f\u89c8\u5668\u4e00\u822c\u53ea\u5141\u8bb8\u5b58\u653e300\u4e2aCookie\uff0c\u6bcf\u4e2a\u7ad9\u70b9\u6700\u591a\u5b58\u653e20\u4e2aCookie\uff0c\u6bcf\u4e2aCookie\u7684\u5927\u5c0f\u9650\u5236\u4e3a4KB<\/p>\n
\u5982\u4f55\u521b\u5efacookie<\/span><\/p>\n
\/\/\u521b\u5efacookie<\/span>
\nCooKie ck=new CooKie(“name”,”abc”);
\n\/\/\u8bbe\u7f6ecookie\u8def\u5f84\uff0c\u5f53\u524d\u670d\u52a1\u5668\u4e0b<\/span>
\nck.setPath(“\/”);
\n\/\/cookie\u751f\u547d\u5468\u671f<\/span>\uff1a\u8d1f\u6570—>\u6d4f\u89c8\u5668\u5185\u5b58\u91cc\uff0c0–>\u5931\u6548\uff0c\u6b63\u6570–>\u751f\u6548\u65f6\u95f4(\u79d2)
\nck.setMaxAge(-1);
\n\/\/\u8ba9\u6d4f\u89c8\u5668\u6dfb\u52a0cookie<\/span>
\nresponse.addCookie(ck);
\n====================================
\ncookie\u7684\u67e5\u8be2\u3001\u4fee\u6539<\/span><\/p>\n
\u67e5\u8be2<\/p>\n
Cookie[] cookies = request.getCookies();\r\nif(cookies.length!=0){\r\n    for (Cookie cookie : cookies) {\r\n        String name = cookie.getName();\r\n        if(\"username\".equals(name)){\r\n            if(\"zhangsan\".equals(cookie.getValue())){\r\n                System.out.println(\"\u5f53\u524d\u5df2\u7ecf\u767b\u9646\u8fc7\u4e86\");\r\n            }\r\n        }\r\n    }\r\n}<\/pre>\n
\u4fee\u6539\u8ddf\u521b\u5efa\u4e00\u6837
\n\u53ea\u9700\u8981\u4fdd\u8bc1cookie\u7684\u540d\u548c\u8def\u5f84\u4e00\u81f4\u5373\u53ef\u4fee\u6539<\/p>\n
cookie\u7684\u751f\u5b58\u65f6\u95f4<\/span>
\n\u9ed8\u8ba4-1\uff0c\u6d4f\u89c8\u5668\u5173\u95ed\u5931\u6548
\n\u53d6\u503c\u8bf4\u660e\uff1a
\n>0\u6709\u6548\u671f,\u5355\u4f4d\u79d2
\n=0\u5931\u6548
\n<0\u5185\u5b58\u5b58\u50a8<\/p>\n
====================================
\ncookie\u751f\u547d\u5468\u671f\u548c\u5171\u4eab\u8303\u56f4<\/span><\/p>\n
ck.setPath(“\/”);\/\/\u8bbe\u7f6ecookie\u8def\u5f84\uff0c\u5f53\u524d\u670d\u52a1\u5668\u4e0b
\nck.setMaxAge(-1);\/\/cookie\u751f\u547d\u5468\u671f<\/p>\n
====================================
\ncookie\u7684\u7f16\u7801\u548c\u89e3\u7801<\/span>
\n\u7f16\u7801
\nURLEndoer.encode(“\u59d3\u540d”,”UTF-8″)<\/p>\n
\u89e3\u7801
\nURLDecoder.decode(name,”UTF-8″).equals(“\u59d3\u540d”);
\n====================================
\n\u4f18\u70b9<\/span>
\n\u53ef\u914d\u7f6e\u5230\u671f\u89c4\u5219\uff1aCookie\u53ef\u4ee5\u5728\u6d4f\u89c8\u5668\u4f1a\u8bdd\u7ed3\u675f\u65f6\u5230\u671f\uff0c\u6216\u8005\u53ef\u4ee5\u5728\u5ba2\u6237\u7aef\u8ba1\u7b97\u673a\u4e0a\u65e0\u9650\u671f\u5b58\u5728\uff0c
\n\u8fd9\u53d6\u51b3\u4e8e\u5ba2\u6237\u7aef\u7684\u5230\u671f\u89c4\u5219\uff0c\u4e0d\u9700\u8981\u4efb\u4f55\u670d\u52a1\u5668\u8d44\u6e90\uff0ccookie\u5b58\u50a8\u5728\u5ba2\u6237\u7aef\u5e76\u5728\u53d1\u9001\u540e\u7531\u670d\u52a1\u5668\u8bfb\u53d6\u3002
\n\u7b80\u5355\u6027\uff1aCookie\u662f\u4e00\u79cd\u57fa\u4e8e\u6587\u672c\u7684\u8f7b\u91cf\u7ed3\u6784\uff0c\u5305\u542b\u7b80\u5355\u7684\u952e\u503c\u5bf9\u3002
\n\u6570\u636e\u6301\u4e45\u6027\uff1a\u867d\u7136\u5ba2\u6237\u7aef\u8ba1\u7b97\u673a\u4e0aCookie\u7684\u6301\u7eed\u65f6\u95f4\u53d6\u51b3\u4e8e\u5ba2\u6237\u7aef\u4e0a\u7684Cookie\u8fc7\u671f\u5904\u7406\u548c\u7528\u6237\u5e72\u9884\uff0c
\nCookie\u901a\u5e38\u662f\u5ba2\u6237\u7aef\u4e0a\u6301\u7eed\u65f6\u95f4\u6700\u957f\u7684\u6570\u636e\u4fdd\u7559\u5f62\u5f0f<\/p>\n
\u7f3a\u70b9<\/span>
\n\u5927\u5c0f\u53d7\u5230\u9650\u5236\uff1a\u5927\u591a\u6570\u6d4f\u89c8\u5668\u5bf9Cookie\u7684\u5927\u5c0f\u67094096\u5b57\u8282\u7684\u9650\u5256\uff0c\u5c3d\u7ba1\u5728\u5f53\u4eca\u65b0\u7684\u6d4f\u89c8\u5668\u548c
\n\u5ba2\u6237\u7aef\u8bbe\u5907\u7248\u672c\u4e2d\uff0c\u652f\u63018192\u5b57\u8282\u7684Cookie\u5927\u5c0f\u5df2\u6108\u53d1\u5e38\u89c1\u3002
\n\u7528\u6237\u914d\u7f6e\u4e3a\u7981\u7528\uff1a\u6709\u4e9b\u7528\u6237\u7981\u7528\u4e86\u6d4f\u89c8\u5668\u6216\u5ba2\u6237\u7aef\u8bbe\u5907\u63a5\u6536Cookie\u7684\u80fd\u529b\uff0c\u56e0\u6b64\u9650\u5236\u4e86\u8fd9\u4e00\u529f\u80fd\u3002
\n\u6f5c\u5728\u7684\u5b89\u5168\u98ce\u9669\uff1aCookie\u53ef\u80fd\u4f1a\u88ab\u5893\u6539\u3002\u7528\u6237\u53ef\u80fd\u4f1a\u64cd\u7eb5\u5176\u8ba1\u7b97\u673a\u4e0a\u7684Cookie\uff0c
\n\u8fd9\u610f\u5473\u7740\u4f1a\u5bf9\u5b89\u5168\u6027\u9020\u6210\u6f5c\u5728\u98ce\u9669\u6216\u8005\u5bfc\u81f4\u4f9d\u8d56\u4e8eCookie\u7684\u5e94\u7528\u7a0b\u5e8f\u5931\u8d25\u3002<\/p>\n
====================================
\nsession\u57fa\u7840<\/span><\/strong><\/p>\n
\u4ec0\u4e48\u662fsession<\/span>
\nsession\u7528\u4e8e\u8ddf\u8e2a\u5ba2\u6237\u7aef\u7684\u72b6\u6001\uff0csession\u6307\u7684\u662f\u5728\u4e00\u6bb5\u65f6\u95f4\u5185\uff0c\u5355\u4e2a\u5ba2\u6237\u7aef\u4e0eweb\u670d\u52a1\u5668\u7684\u4e00\u8fde\u4e32\u76f8\u5173\u7684
\n\u4ea4\u4e92\u8fc7\u7a0b\u3002
\n\u5728\u4e00\u4e2asession\u4e2d\uff0c\u5ba2\u6237\u53ef\u80fd\u4f1a\u591a\u6b21\u8bf7\u6c42\u8bbf\u95ee\u540c\u4e00\u4e2a\u7f51\u9875\uff0c\u4e5f\u6709\u53ef\u80fd\u8bf7\u6c42\u8bbf\u95ee\u5404\u79cd\u4e0d\u540c\u7684\u670d\u52a1\u5668\u8d44\u6e90\u3002<\/p>\n
session\u5de5\u4f5c\u539f\u7406<\/span>
\nsession\u88ab\u7528\u4e8e\u8868\u793a\u4e00\u4e2a\u6301\u7eed\u7684\u8fde\u63a5\u72b6\u6001\uff0c\u5728\u7f51\u7ad9\u8bbf\u95ee\u4e2d\u4e00\u822c\u6307\u4ee3\u5ba2\u6237\u7aef\u6d4f\u89c8\u5668\u7684\u8fdb\u7a0b\u4ece\u5f00\u542f\u5230\u7ed3\u675f\u7684\u8fc7\u7a0b\u3002
\nsession\u5176\u5b9e\u5c31\u662f\u7f51\u7ad9\u5206\u6790\u7684\u8bbf\u95ee(visits)\u5ea6\u91cf\uff0c\u8868\u793a\u4e00\u4e2a\u8bbf\u95ee\u7684\u8fc7\u7a0b\u3002
\nsession\u7684\u5e38\u89c1\u5b9e\u73b0\u5f62\u5f0f\u662fcookie(session cookie\uff09\uff0c\u5373\u672a\u8bbe\u7f6e\u8fc7\u671f\u65f6\u95f4\u7684cookie\uff0c\u8fd9\u4e2acookie\u7684\u9ed8\u8ba4\u751f\u547d\u5468\u671f
\n\u4e3a\u6d4f\u89c8\u5668\u4f1a\u8bdd\u671f\u95f4\uff0c\u53ea\u8981\u5173\u95ed\u6d4f\u89c8\u5668\u7a97\u53e3\uff0ccookie\u5c31\u6d88\u5931\u4e86\u3002\u5b9e\u73b0\u673a\u5236\u662f\u5f53\u7528\u6237\u53d1\u8d77\u4e00\u4e2a\u8bf7\u6c42\u7684\u65f6\u5019\uff0c
\n\u670d\u52a1\u5668\u4f1a\u68c0\u67e5\u8be5\u8bf7\u6c42\u4e2d\u662f\u5426\u5305\u542bsessionid\uff0c\u5982\u679c\u672a\u5305\u542b\uff0c\u5219Tomcat\u4f1a\u521b\u9020\u4e00\u4e2a\u540d\u4e3aJSESSIONID\u7684\u8f93\u51fa
\ncookie\u8fd4\u56de\u7ed9\u6d4f\u89c8\u5668(\u53ea\u653e\u5165\u5185\u5b58\uff0c\u5e76\u4e0d\u5b58\u5728\u786c\u76d8\u4e2d)\uff0c\u5e76\u5c06\u5176\u4ee5HashTable\u7684\u5f62\u5f0f\u5199\u5230\u670d\u52a1\u5668\u7684\u5185\u5b58\u91cc\u9762\uff1b
\n\u5f53\u5df2\u7ecf\u5305\u542bsessionid\u65f6\uff0c\u670d\u52a1\u7aef\u4f1a\u68c0\u67e5\u627e\u5230\u4e0e\u8be5session\u76f8\u5339\u914d\u7684\u4fe1\u606f\uff0c\u5982\u679c\u5b58\u5728\u5219\u76f4\u63a5\u4f7f\u7528\u8be5sessionid\uff0c
\n\u82e5\u4e0d\u5b58\u5728\u5219\u91cd\u65b0\u751f\u6210\u65b0\u7684session\u3002\u8fd9\u91cc\u9700\u8981\u6ce8\u610f\u7684\u662fsession\u59cb\u7ec8\u662f\u6709\u670d\u52a1\u7aef\u521b\u5efa\u7684\uff0c\u5e76\u975e\u6d4f\u89c8\u5668\u81ea\u5df1\u751f\u6210\u7684\u3002<\/p>\n
\u5982\u4f55\u83b7\u5f97session<\/span><\/strong><\/p>\n
\/\/\u83b7\u53d6session\u5bf9\u8c61<\/span>\uff0c\u5148\u5224\u65ad\u8bf7\u6c42\u5185\u5bb9\u91cc\u662f\u5426\u5305\u542b\u4e86session\u3002\u5982\u679c\u6ca1\u6709\u5219\u4f1a\u81ea\u52a8\u521b\u5efa
\nHttpSession session=request.getSession();
\nsout(“Id:”+session.getId()<\/span>);\/\/\u552f\u4e00\u6807\u8bb0
\nsout(“\u6700\u540e\u4e00\u6b21\u8bbf\u95ee\u65f6\u95f4<\/span>\uff0c\u6beb\u79d2”+session.getLastAccessedTime()<\/span>);
\nsout(“\u83b7\u53d6\u6700\u5927\u7684\u7a7a\u95f2\u65f6\u95f4<\/span>\uff0c\u5355\u4f4d\u79d2”+session.getMaxInactiveInterval()<\/span>);\/\/\u9ed8\u8ba4session\u5931\u6548\u65f6\u95f430\u5206\u949f<\/span>
\nsout(“\u83b7\u53d6session\u7684\u521b\u5efa<\/span>\uff0c\u5355\u4f4d\u6beb\u79d2”+session.getCreationTime()<\/span>);<\/p>\n
\u5982\u4f55\u4f7f\u7528session\u7ed1\u5b9a\u5bf9\u8c61<\/span>
\n\u4f7f\u7528HttpSession\u7684setAttribute(\u5c5e\u6027\u540d,object)\u65b9\u6cd5<\/p>\n
\u5982\u4f55\u5220\u9664session
\n\u4f7f\u7528HttpSession\u7684invalidate\u65b9\u6cd5<\/p>\n
====================================<\/p>\n
Session\u8d85\u65f6<\/span><\/strong><\/p>\n
\u4ec0\u4e48\u662fsession\u8d85\u65f6<\/span>\uff1aHttpSession\u7684\u6700\u540e\u4e00\u6b21\u8bbf\u95ee\u65f6\u95f4\u548c\u5f53\u524d\u65f6\u95f4\u7684\u5dee\u8ddd\u5927\u4e8e\u4e86\u6307\u5b9a\u7684\u6700\u5927\u7a7a\u95f2\u65f6\u95f4\uff0c\u8fd9\u65f6\u670d\u52a1\u5668\u5c31\u4f1a\u9500\u6bc1Session\u5bf9\u8c61\u3002\u9ed8\u8ba4\u7684\u7a7a\u95f2\u65f6\u95f4\u4e3a30\u5206\u949f\u3002<\/p>\n
\u4fee\u6539session\u7f3a\u7701\u65f6\u95f4\u9650\u5236\uff1a<\/span><\/p>\n
1 \u4f7f\u7528HttpSession\u7684session.setMaxInactiveInterval(20*60)<\/span>;\u8bbe\u7f6e\uff0c\u5355\u4f4d\u79d2
\n2 \u5728web.xml\u4e2d\u914d\u7f6e \uff0c\u5355\u4f4d\u5206\u949f
\n<session-config><\/span>
\n<session-timeout>20<\/session-timeout><\/span>
\n<\/session-config><\/span>
\n\u4e0d\u51b2\u7a81<\/span><\/strong><\/p>\n
session\u5931\u6548\u7684\u51e0\u79cd\u60c5\u51b5\uff1a<\/span><\/strong><\/p>\n
1\u3001\u8d85\u8fc7\u4e86\u8bbe\u7f6e\u7684\u8d85\u65f6\u65f6\u95f4<\/span>
\n2\u3001\u4e3b\u52a8\u8c03\u7528\u4e86invalidate\u65b9\u6cd5<\/span>
\n3\u3001\u670d\u52a1\u5668\u4e3b\u52a8\u6216\u5f02\u5e38\u5173\u95ed<\/span>
\n\u6ce8\u610f\uff1a\u6d4f\u89c8\u5668\u5173\u95ed\u5e76\u4e0d\u4f1a\u8ba9Session\u5931\u6548<\/span><\/p>\n
====================================
\n\u6d4f\u89c8\u5668\u7981\u7528cookie\u7684\u540e\u679c<\/span><\/p>\n
\u5982\u679c\u6d4f\u89c8\u5668\u7981\u7528cookie\uff0csession\u8fd8\u80fd\u7528\u5417\uff1f
\n\u7b54\uff1a\u4e0d\u80fd\uff0c\u4f46\u6709\u5176\u4ed6\u7684\u89e3\u51b3\u65b9\u6848
\n\u670d\u52a1\u5668\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c\u4f1a\u4f7f\u7528cookie\u7684\u65b9\u5f0f\u5c06sessionID\u53d1\u9001\u7ed9\u6d4f\u89c8\u5668\uff0c\u5982\u679c\u7528\u6237\u7981\u6b62cookie\uff0c
\n\u5219sessionID\u4e0d\u4f1a\u88ab\u6d4f\u89c8\u5668\u4fdd\u5b58\uff0c\u6b64\u65f6\uff0c\u670d\u52a1\u5668\u53ef\u4ee5\u4f7f\u7528\u5982URL\u91cd\u5199\u8fd9\u6837\u7684\u65b9\u5f0f\u6765\u53d1\u9001sessionID<\/p>\n
\u4f7f\u7528session\u533a\u5206\u6bcf\u4e2a\u7528\u6237\u7684\u65b9\u5f0f\uff1a
\n1.\u4f7f\u7528cookie
\n2.\u5ea7\u4f4d\u9690\u85cf\u57df\u5d4c\u5165html\u8868\u5355\u4e2d\uff0c\u9644\u52a0\u5728\u4e3b\u4f53\u7684URL\u4e2d\uff0c\u901a\u5e38\u4f5c\u4e3a\u6307\u5411\u5176\u4ed6\u5e94\u7528\u7a0b\u5e8f\u9875\u9762\u7684\u94fe\u63a5\uff0c\u5373URL\u91cd\u5199<\/p>\n
\u4ec0\u4e48\u662fURL\u91cd\u5199<\/span>
\n\u6d4f\u89c8\u5668\u5728\u8bbf\u95ee\u670d\u52a1\u5668\u4e0a\u7684\u67d0\u4e2a\u5730\u5740\u65f6\uff0c\u4e0d\u518d\u4f7f\u7528\u539f\u6765\u7684\u90a3\u4e2a\u5730\u5740\uff0c\u800c\u662f\u4f7f\u7528\u7ecf\u8fc7\u6539\u5199\u7684\u5730\u5740\uff0c
\n\u5373\uff0c\u5728\u539f\u6765\u7684\u5730\u5740\u540e\u9762\u52a0\u4e0a\u4e86sessionID<\/p>\n
\u5982\u4f55\u5b9e\u73b0URL\u91cd\u5199
\n\u5982\u679c\u662f\u94fe\u63a5\u5730\u5740\u548c\u8868\u5355\u63d0\u4ea4\uff0c\u4f7f\u7528response.encodeURL(String url)\u751f\u6210\u91cd\u5199\u540e\u7684URL
\nString s=response.encodeURL(“\u9879\u76ee\/\u8d44\u6e90”);
\nsout(s);
\nwriter.println(“<a href=”&quot;+s+&quot;”>”+”\u8df3\u8f6c”+”<\/a>”);<\/p>\n
\u5982\u679c\u91cd\u5b9a\u5411\uff0c\u4f7f\u7528response.encodeRedirectURL(String url)\u751f\u6210\u91cd\u5199\u540e\u7684URL
\nString s=response.encodeRedirectURL(“\u9879\u76ee\/\u8d44\u6e90”);
\nresponse.sendRedirect(s);<\/p>\n
====================================
\nsession\u8d85\u65f6<\/span><\/p>\n
\u4ec0\u4e48\u662fsession\u8d85\u65f6
\nHttpSession\u7684\u6700\u540e\u4e00\u6b21\u8bbf\u95ee\u65f6\u95f4\u548c\u5f53\u524d\u65f6\u95f4\u7684\u5dee\u8ddd\u5927\u4e8e\u4e86\u6307\u5b9a\u7684\u6700\u5927\u7a7a\u95f2\u65f6\u95f4\uff0c\u8fd9\u65f6\u670d\u52a1\u5668\u5c31\u4f1a
\n\u9500\u6bc1session\u5bf9\u8c61\uff0c\u9ed8\u8ba4\u7684\u7a7a\u95f2\u65f6\u95f4\u662f30\u5206\u949f<\/p>\n
\u5982\u4f55\u4fee\u6539session\u7684\u7f3a\u7701\u65f6\u95f4\u9650\u5236
\n1.HttpSession\u7684session.setMaxInactiveInterval(20*60);\/\/\u8bbe\u7f6e\uff0c\u5355\u4f4d\u79d2
\n2.\u5728web.xml\u4e2d\u914d\u7f6e\uff0c\u5355\u4f4d\u5206\u949f<\/p>\n
20<\/p>\n
session\u5931\u6548\u7684\u51e0\u79cd\u60c5\u51b5<\/span>
\n1.\u8d85\u8fc7\u4e86\u8bbe\u7f6e\u7684\u8d85\u65f6\u65f6\u95f4<\/span>
\n2.\u4e3b\u52a8\u8c03\u7528invalidate\u65b9\u6cd5<\/span>
\n3.\u670d\u52a1\u5668\u4e3b\u52a8\u6216\u5f02\u5e38\u5173\u95ed<\/span>
\n\u6ce8\u610f\uff1a\u6d4f\u89c8\u5668\u5173\u95ed\u5e76\u4e0d\u4f1a\u8ba9session\u5931\u6548<\/span><\/p>\n
====================================
\n\u9a8c\u8bc1\u767b\u5f55<\/span><\/p>\n
\/\/1.\u83b7\u53d6session\r\nHttpSession session = request.getSession();\r\n\/\/2.\u83b7\u53d6\u7528\u6237\u540d\r\nString username1 = (String) session.getAttribute(\"username\");\r\nUsersDao ud=new UsersDaoImpl();\r\n\/\/3.\u67e5\u8be2\u6240\u6709\u7528\u6237\r\nList<Users> all = ud.getAll();\r\n\/\/4.\u904d\u5386\u6240\u6709\u7528\u6237\r\nfor (Users users : all) {\r\n    \/\/\u5982\u679c\u83b7\u53d6\u5230\u7684\u7528\u6237\u540d\u4e3a\u7a7a\r\n    if(username1==null) {\r\n        \/\/\u4ece\u8868\u5355\u83b7\u53d6\u7528\u6237\u4f20\u5165\u7684\u503c\r\n        String username = request.getParameter(\"username\");\r\n        String password = request.getParameter(\"password\");\r\n        \/\/\u5c06\u7528\u6237\u8f93\u5165\u7684\u503c\u4e0e\u6570\u636e\u5e93\u91cc\u7684\u7528\u6237\u6570\u636e\u6bd4\u8f83\r\n        if( users.getUsername().equals(username)\r\n                && users.getPassword().equals(password) ){\r\n            \/\/\u7528\u6237\u8f93\u5165\u6b63\u786e\u5c06\u7528\u6237\u540d\u5b58\u5165\u4f5c\u7528\u57df\r\n            session.setAttribute(\"username\",username);\r\n            \/\/\u767b\u5f55\u540e\u8df3\u8f6c\u5230\u9996\u9875\r\n            response.sendRedirect(\"\/servlets\/home.html\");\r\n            return;\r\n        }else{\r\n            \/\/\u5982\u679c\u7528\u6237\u8f93\u5165\u7684\u503c\u4e0d\u5339\u914d\u5219\u8df3\u8f6c\u5230\u767b\u9646\u5931\u8d25\u9875\u9762\r\n            response.sendRedirect(\"\/servlets\/filed.html\");\r\n            return;\r\n        }\r\n    }else{\/\/\u5982\u679c\u7528\u6237\u5df2\u767b\u5f55\u5219\u8df3\u8f6c\u5230\u9996\u9875\r\n        response.sendRedirect(\"\/servlets\/home.html\");\r\n        return;\r\n    }\r\n}<\/pre>\n
\u9000\u51fa\u767b\u5f55<\/span><\/p>\n
HttpSession session = request.getSession();\r\nsession.removeAttribute(\"users\");\r\nsession.invalidate();\r\nresponse.sendRedirect(\"\/servlets\/login.html\");<\/pre>\n
====================================
\n\u9a8c\u8bc1\u7801\u767b\u5f55<\/span><\/p>\n
Validateservlet:
\n\u5bfcjar\u5305ValidateCode.jar<\/p>\n
ValidateCode code=new ValidateCode(120,60,4,1);\/\/\u5bbd\u3001\u9ad8\u3001\u51e0\u4e2a\u5b57\u7b26\u3001\u5e72\u6270\u7ebf\r\nString code1 = code.getCode();\r\nHttpSession session = request.getSession();\r\nsession.setAttribute(\"code\",code);\/\/\u901a\u8fc7session\u628a\u9a8c\u8bc1\u7801\u5b58\u5165\u4f5c\u7528\u57df\r\ncode.write(response.getOutputStream());<\/pre>\n
html:
\n\u9a8c\u8bc1\u7801<input name=”validate” type=”text” \/><img src=”\u9879\u76ee\/Validateservlet” \/><\/p>\n
====================================<\/p>\n
ServletContext\u5bf9\u8c61<\/span><\/strong><\/p>\n
\u4ec0\u4e48\u662fServletContext\uff1fServletContext\uff1aservlet\u4e0a\u4e0b\u6587<\/span><\/p>\n
\u5f53WEB\u670d\u52a1\u5668\u542f\u52a8\u65f6\uff0c\u4f1a\u4e3a\u6bcf\u4e00\u4e2aWEB\u5e94\u7528\u7a0b\u5e8f(webapps\u4e0b\u7684\u6bcf\u4e2a\u76ee\u5f55\u5c31\u662f\u4e00\u4e2a\u5e94\u7528\u7a0b\u5e8f)\u521b\u5efa\u4e00\u5757\u5171\u4eab\u7684\u5b58\u50a8\u533a\u57df
\nServletContext\u4e5f\u53eb\u505a\u201c\u516c\u5171 \u533a\u57df\u201d\uff0c\u4e5f\u5c31\u662f\u540c\u4e00\u4e2aWEB\u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0c\u6240\u6709\u7684Servlet\u548cJSP\u90fd\u53ef\u4ee5\u5171\u4eab\u540c\u4e00\u4e2a\u533a\u57df\u3002
\nServletContext\u5728WEB\u670d\u52a1\u5668\u542f\u52a8\u65f6\u521b\u5efa\uff0c\u670d\u52a1\u5668\u5173\u95ed\u65f6\u9500\u6bc1\u3002<\/p>\n
\u5982\u679c\u83b7\u5f97servlet\u4e0a\u4e0b\u6587<\/span><\/p>\n
\u65b9\u5f0f\u4e00:GenericServlet\u63d0\u4f9b\u4e86getServletContext()\u65b9\u6cd5\u3002\uff08\u63a8\u8350\uff09
\n\u65b9\u5f0f\u4e8c:ServletConfig\u63d0\u4f9b\u4e86getServletContext()\u65b9\u6cd5\u3002
\n\u65b9\u5f0f\u4e09:HttpSession\u63d0\u4f9b\u4e86getServletContext()\u65b9\u6cd5\u3002
\n\u65b9\u5f0f\u56db:HttpServletRequest\u63d0\u4f9b\u4e86getServletContext()\u65b9\u6cd5\u3002(\u63a8\u8350)<\/p>\n
servlet\u4e0a\u4e0b\u6587\u7684\u4f5c\u7528\u53ca\u7279\u70b9<\/span><\/strong><\/p>\n
\u4f5c\u7528\uff1a<\/span>
\n1.\u83b7\u53d6\u771f\u5b9e\u8def\u5f84<\/span><\/p>\n
request.getServletContext().getRealPath(\"\/\");\r\n2.\u83b7\u53d6\u5bb9\u5668\u9644\u52a0\u4fe1\u606f<\/span><\/pre>\n
String serverInfo = request.getServletContext().getServerInfo();\r\nString contextPath = request.getServletContext().getContextPath();\r\nString contextPath1 = request.getContextPath();<\/pre>\n
3.\u5168\u5c40\u5bb9\u5668<\/span><\/p>\n
\/\/\u8bbe\u7f6e\u4fe1\u606f\u5230\u5168\u5c40\u5bb9\u5668\u4e2d\r\nrequest.getServletContext().setAttribute(\"msg\",\"\u5171\u4eab\u4fe1\u606f\");\r\n\/\/\u83b7\u53d6\u6570\u636e\r\nString msg = (String) request.getServletContext().getAttribute(\"msg\");\r\nresponse.getWriter().write(msg);\r\nSystem.out.println(msg);\r\n\/\/\u79fb\u9664\u6570\u636e\r\nrequest.getServletContext().removeAttribute(\"msg\");<\/pre>\n
\u7279\u70b9\uff1a<\/span><\/p>\n
\u552f\u4e00\u6027: \u4e00\u4e2a\u5e94\u7528\u5bf9\u5e94\u4e00\u4e2aservlet\u4e0a\u4e0b\u6587\u3002<\/span>
\n\u4e00\u76f4\u5b58\u5728: \u53ea\u8981\u5bb9\u5668\u4e0d\u5173\u95ed\u6216\u8005\u5e94\u7528\u4e0d\u5378\u8f7d\uff0cservlet\u4e0a\u4e0b\u6587\u5c31\u4e00\u76f4\u5b58\u5728\u3002<\/span><\/p>\n
====================================<\/p>\n
web.xml\u6587\u4ef6\u914d\u7f6eservletContext\u53c2\u6570
\n<!– \u914d\u7f6e\u5e94\u7528\u7a0b\u5e8f\u7684\u521d\u59cb\u5316\u53c2\u6570 –><\/p>\n
<context-param>
\n<param-name>appname<\/param-name>
\n<param-value>xxx\u7ba1\u7406\u7cfb\u7edf<\/param-value>
\n<\/context-param><\/p>\n
<context-param>
\n<param-name>appversion<\/param-name>
\n<param-value>2.0<\/param-value>
\n<\/context-param><\/p>\n
\/\/\u83b7\u53d6servlet\u4e0a\u4e0b\u6587\u53c2\u6570
\nString appname=application.getInitParameter(“appname”);
\nString appversion=application.getInitParameter(“appversion”);
\nSystem.out.println(appname+”…”+appversion);<\/p>\n
====================================<\/p>\n
ServletContext\u7edf\u8ba1Servlet\u8bbf\u95ee\u6b21\u6570<\/span><\/strong><\/p>\n
ServletContext sc = request.getServletContext();\r\nInteger num = (Integer) sc.getAttribute(\"num\");\r\nif (num == null) {\r\n    num=1;\r\n    sc.setAttribute(\"num\",num);\r\n}else{\r\n    num++;\r\n    sc.setAttribute(\"num\",num);\r\n}\r\nresponse.getWriter().write(\"\u603b\u8bbf\u95ee\uff1a\"+num+\"\u6b21\");<\/pre>\n","protected":false},"excerpt":{"rendered":"
Javaweb\u6559\u7a0b\uff1aservlet\u72b6\u6001\u7ba1\u7406 servlet\u72b6\u6001\u7ba1\u7406 servlet\u751f\u547d\u5468\u671f \u9636\u6bb5\u4e00\uff1a\u5b9e\u4f8b\u5316(\u8c03 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-2419","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2419","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2419"}],"version-history":[{"count":4,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2419\/revisions"}],"predecessor-version":[{"id":2423,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2419\/revisions\/2423"}],"wp:attachment":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2419"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2419"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2419"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}