Java Web 怎样修改request的参数值

Posted 2023-04-28

用过滤器就可以实现，现在web.xml文件中配置好过滤器，自定义个一个过滤器，实现Filter接口，在doFilter中实现自己的过滤逻辑，我这里有个设置所有请求中的字符编码，你可以参考一下：
Java code

web.xml配置如下：
<filter>
<!--过滤器名称，随便定义-->
<filter-name>UrlFilter</filter-name>
<!--filter-class指向自定义的过滤器，完整的包名+类名-->
<filter-class>
com.wgh.common.SetCharacterEncodingFilter
</filter-class>
<!--过滤器中的默认参数，默认的字符编码是GBK-->
<init-param>
<param-name>defaultEncoding</param-name>
<param-value>GBK</param-value>
</init-param>
</filter>
<!--filter和filter-mapping是成对出现的-->
<filter-mapping>
<!--过滤器名称，一定要和上面的一样，-->
<filter-name>UrlFilter</filter-name>
<!--表示拦截所有的请求-->
<url-pattern>/*</url-pattern>
</filter-mapping>

SetCharacterEncodingFilter过滤器类：

package com.wgh.common;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.List;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class SetCharacterEncodingFilter implements Filter

private static String log = "ksURL_log";
private static String web_xml_url;

protected static String defaultEncoding = null;
protected FilterConfig filterConfig = null;
protected boolean ignore = true;

public void destroy()
this.defaultEncoding = null;
this.filterConfig = null;
this.web_xml_url = null;



public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException
if (ignore || (request.getCharacterEncoding() == null))
String defaultEncoding = selectEncoding(request);

HttpServletRequest req = (HttpServletRequest) request;
if (defaultEncoding != null)
String uri = req.getRequestURI();
String url_suffix = uri.substring(uri.lastIndexOf("/")+1);

request.setCharacterEncoding(defaultEncoding);





public void init(FilterConfig filterConfig) throws ServletException

this.filterConfig = filterConfig;
this.defaultEncoding = filterConfig.getInitParameter("defaultEncoding");
String value = filterConfig.getInitParameter("ignore");
if (value == null)
this.ignore = true;
else if (value.equalsIgnoreCase("true"))
this.ignore = true;
else if (value.equalsIgnoreCase("yes"))
this.ignore = true;
else
this.ignore = false;



protected String selectEncoding(ServletRequest request)
return (this.defaultEncoding);


参考技术A 用过滤器就可以实现，现在web.xml文件中配置好过滤器，

自定义个一个过滤器，实现Filter接口，在doFilter中实现自己的过滤逻辑。

java获取request的url方法区别

1、request.getRequestURL()

返回的是完整的url，包括Http协议，端口号，servlet名字和映射路径，但它不包含请求参数。
2、request.getRequestURI()

得到的是request URL的部分值，并且web容器没有decode过的

3、request.getContextPath() 
返回 the context of the request.

4、request.getServletPath() 
返回调用servlet的部分url.

5、request.getQueryString() 
返回url路径后面的查询字符串

示例：

当前url：http://localhost:8080/CarsiLogCenter_new/idpstat.jsp?action=idp.sptopn

request.getRequestURL() http://localhost:8080/CarsiLogCenter_new/idpstat.jsp
request.getRequestURI() /CarsiLogCenter_new/idpstat.jsp
request.getContextPath()/CarsiLogCenter_new
request.getServletPath() /idpstat.jsp

request.getQueryString()action=idp.sptopn

来源： http://blog.csdn.net/gris0509/article/details/6340987

来自为知笔记(Wiz)