[急！！！！] servlet 过滤器问题

2008-12-27 02:05:35 190 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

SERVLET过滤器全球因特网用户使用不同类型的Web浏览器访问应用服务器上存储的Web应用程序。每个浏览器根据对应的Web浏览器窗口中的设置显示应用程序中的信息。Web应用程序可能会有一些客户机的Web浏览器不支持的HTML标记或功能。这种情况下，应用程序在客户机的Web浏览器中可能运行，可能不运行，还可能生成不需要的输出。为了避免这种问题，在调用servlet之前需要识别浏览器的类型和向Web应用程序发送请求的客户机和其他特定的信息。阅读详情



package TestFilter;

import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;



public class NoteServlet extends HttpServlet {

public final static String type="text/html;charset=GB2312";

 public void doGet(HttpServletRequest request,HttpServletResponse response) 

 throws IOException,ServletException {

	 response.setContentType(type);

	 ServletOutputStream out=response.getOutputStream();

	 out.println("<html>");

	 out.println("<head><title>留言簿</title><body>");

	 String userName=request.getParameter("userName");

	 String content=request.getParameter("content");

	 if(userName!=null){

		 userName=new String(userName.getBytes("ISO-8859-1"),"GB2312");

		 content=new String(content.getBytes("ISO-8859-1"),"GB2312");

	 }

	 if(content!=null&&!content.equals("")){

		 out.println("<p><h3>"+userName+"的留言为："+content+"</h3></p>");

	 }

	 out.println("<form action="+request.getContextPath()+"/note method=get />");

	 out.println("<b>姓名：</b>");

	 out.println("<input type=text size=10 name=userName><BR>");

	 out.println("<b>留言：</b><BR>");

	 out.println("<textArea name=content rows=5 cols=20 wrap></textArea><br>");

	 out.println("<BR>");

	 out.println("<input type=submit value='提交'>");

	 out.println("</form>");

	 out.println("</body></html>");

 }

 public void doPost(HttpServletRequest request,HttpServletResponse response)throws IOException,ServletException {

	  doGet(request,response);

 }

 public void destroy(){

 }

}





第二个：

package TestFilter;



import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;



public class NoteFilter implements Filter{

  private FilterConfig config=null;

  private String blackList;

 

  public void init(FilterConfig config){

	  this.config=config;

	  blackList=config.getInitParameter("blackList");

  }

  

  public void doFilter(ServletRequest request,ServletResponse response,FilterChain chain)

  throws IOException,ServletException{

	boolean available=false; 

	String userName=((HttpServletRequest)request).getParameter("userName");

	if(userName!=null){

		userName=new String(userName.getBytes("ISO-8859-1"),"GB2312");

	}

  String[]str=blackList.split(",");

  for(int i=0;i<str.length;i++){

	  if(userName.indexOf(str[i])!=-1){

		  available=true;

		  break;

	  }

  }

  if(userName!=null&&available){

	  response.setContentType("text/html;charset=gb2312");

	  PrintWriter out=response.getWriter();

	  out.println("<html><head><title>NoteFilter过滤器</title></head><body>");

	  out.println("<center><font color=red>对不起"+userName+

			  "你已经被加入了黑名单，你没有留言权限！！！</font></center>");

	  out.println("</body><html>");

	  out.flush();

	  return ;

  }

  long before=System.currentTimeMillis();

  config.getServletContext().log("NoteFilter:before call chain.doFilter");

  chain.doFilter(request, response);

  config.getServletContext().log("NoteFilter:after call chain.doFilter");

  long after=System.currentTimeMillis();

  String name="";

  if(request instanceof HttpServletRequest){

	  name=((HttpServletRequest)request).getRequestURI();

  }

  config.getServletContext().log("你请求"+name+"所用的时间为"+(after-before));

  

  }

  

  public void destroy(){

		 config=null;

	  }

}

web.xml 配置
<?xml version="1.0" encoding="GB2312"?>

<web-app>
<filter>
<filter-name>NoteFilter</filter-name>
<filter-class>/TestFilter.NoteFilter</filter-class>
<int-param>
<param-name>blackList</param-name>
<param-value>张三,王五,赵六</param-value>
</int-param>
</filter>
<filter-mapping>
<filter-name>NoteFilter</filter-name>
<url-pattern>/note</url-pattern>
</filter-mapping>

<servlet>
<servlet-name>NoteServlet</servlet-name>
<servlet-class>/TestFilter.NoteServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>noteServlet</servlet-name>
<url-pattern>/note</url-pattern>
</servlet-mapping>

</web-app>

在service.xml 中加入了host 下加入了
<Logger className="arg.apache.catalina.logger.FileLogger"
directory="logs" prefix="practice." sufix=".txt"/>

出现了下面的问题：
Thread [main] (Suspended (exception MalformedByteSequenceException))
UTF8Reader.invalidByte(int, int, int) line: not available
UTF8Reader.read(char[], int, int) line: not available
XMLEntityScanner.load(int, boolean) line: not available
XMLEntityScanner.skipString(String) line: not available
XMLVersionDetector.determineDocVersion(XMLInputSource) line: not available
JAXPConfiguration(XML11Configuration).parse(boolean) line: not available
JAXPConfiguration(XML11Configuration).parse(XMLInputSource) line: not available
SAXParser(XMLParser).parse(XMLInputSource) line: not available
SAXParser(AbstractSAXParser).parse(InputSource) line: not available
Digester.parse(InputSource) line: 1644
ContextConfig.applicationWebConfig() line: 365
ContextConfig.start() line: 1066
ContextConfig.lifecycleEvent(LifecycleEvent) line: 261
LifecycleSupport.fireLifecycleEvent(String, Object) line: 117
StandardContext.start() line: 4252
StandardHost(ContainerBase).addChildInternal(Container) line: 791
StandardHost(ContainerBase).addChild(Container) line: 771
StandardHost.addChild(Container) line: 525
HostConfig.deployDirectory(String, File, String) line: 926
HostConfig.deployDirectories(File, String[]) line: 889
HostConfig.deployApps() line: 492
HostConfig.start() line: 1149
HostConfig.lifecycleEvent(LifecycleEvent) line: 311
LifecycleSupport.fireLifecycleEvent(String, Object) line: 117
StandardHost(ContainerBase).start() line: 1053
StandardHost.start() line: 719
StandardEngine(ContainerBase).start() line: 1045
StandardEngine.start() line: 443
StandardService.start() line: 516
StandardServer.start() line: 710
Catalina.start() line: 578
NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method]
NativeMethodAccessorImpl.invoke(Object, Object[]) line: not available
DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: not available
Method.invoke(Object, Object...) line: not available
Bootstrap.start() line: 288
Bootstrap.main(String[]) line: 413

...全文

解决vscode无法运行npm命令的问题(cmd可行) Powershell以及vscode中npm命令使用不了阅读详情

rongyunsheng

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切换为时间正序

startym 2008-12-28

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换编码方式试试吧

rongyunsheng 2008-12-28

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HTTP Status 500 -

--------------------------------------------------------------------------------

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

java.lang.NullPointerException
TestFilter.NoteFilter.doFilter(NoteFilter.java:23)

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.13 logs.

--------------------------------------------------------------------------------

Apache Tomcat/6.0.13

whuzjf1985 2008-12-28

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楼主写得不错一个经典的过滤器

zhj92lxs 2008-12-27

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[Quote=引用 4 楼 wj_18 的回复:]
把字符集换成UTF-8
也能用汉字的
[/Quote]
不错

wj_18 2008-12-27

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把字符集换成UTF-8
也能用汉字的

zw_ydjysc 2008-12-27

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2楼正解，把filter-class中的/去掉

cydp007 2008-12-27

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如果你用 eclipse 写的话应该就不会有了吧.
他给你的配置界面都做好了.

rongyunsheng 2008-12-27

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web.xml 配置
<?xml version="1.0" encoding="GB2312"?>

<web-app>
<filter>
<filter-name>NoteFilter </filter-name>
<filter-class>TestFilter.NoteFilter </filter-class>
<int-param>
<param-name>blackList </param-name>
<param-value>张三,王五,赵六 </param-value>
</int-param>
</filter>
<filter-mapping>
<filter-name>NoteFilter </filter-name>
<url-pattern>/note </url-pattern>
</filter-mapping>

<servlet>
<servlet-name>NoteServlet </servlet-name>
<servlet-class>TestFilter.NoteServlet </servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>NoteServlet </servlet-name>
<url-pattern>/note </url-pattern>
</servlet-mapping>

</web-app> 出现了几个笔误，自己纠正一下

估计是字符编码出了问题找错误头都晕了

cydp007 2008-12-27

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放狗搜了一下 .. 据传是 io的问题. .

你也可以继续放狗搜你那个异常.MalformedByteSequenceException

fujilin 2008-12-27

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好象是这里:
String userName=((HttpServletRequest)request).getParameter("userName");
if(userName!=null){
userName=new String(userName.getBytes("ISO-8859-1"),"GB2312");
}

看看getParameter("userName");前文件的编号是什么,可能不是"GB2312"!

[急！！！！] servlet 过滤器问题

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