超强过滤器

此过滤器主要是统一对对 Tomcat 默认设置下的中文问题进行解决而只需要用新的 Request，其他中间件下未测试。

需要三步操作：

1、编写编码过滤器

2、web.xml配置编码过滤器

3、重启tomcat服务，使过滤器在项目中生效。

过滤器类：

package com.rzq.basePro.web.filter;

import java.io.IOException;
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.HttpServletRequestWrapper;

public class CharsetAllEncodingFilter implements Filter
{

 private String encoding = null;

 /**
 * Request.java 对 HttpServletRequestWrapper 进行扩充, 不影响原来的功能并能提供所有的
  * HttpServletRequest 接口中的功能. 它可以统一的对 Tomcat 默认设置下的中文问题进行解决而只需要用新的 Request
 * 对象替换页面中的 request 对象即可.
  */
  class Request extends HttpServletRequestWrapper
 {

 private String encoding = null;

 public Request(HttpServletRequest request)
  {
 super(request);
 encoding = CharsetAllEncodingFilter.this.encoding;
  }

 /**
 * 转换由表单读取的数据的内码. 从 ISO 字符转到 在web.xml中设置的encoding.
 */
  public String toChi(String input)
 {
 if (input == null)
  {
 return null;
  } else
  {
 try
 {
 byte[] bytes = input.getBytes("ISO8859-1");
 return new String(bytes, encoding);
 } catch (Exception ex)
  {
 }
 return null;
  }
 }

 /**
 * Return the HttpServletRequest holded by this object.
  */
 private HttpServletRequest getHttpServletRequest()
 {
 return (HttpServletRequest) super.getRequest();
 }

 /**
 * 读取参数 -- 修正了中文问题.
  */
  public String getParameter(String name)
 {
 return toChi(getHttpServletRequest().getParameter(name));
 }

 /**
 * 读取参数列表 - 修正了中文问题.
 */
  public String[] getParameterValues(String name)
 {
 String values[] = getHttpServletRequest().getParameterValues(name);
 if (values != null)
 {
 for (int i = 0; i < values.length; i++)
 {
  values[i] = toChi(values[i]);
 }
 }
 return values;
  }
 }

 public void destroy()
 {
 }

 public void doFilter(ServletRequest request, ServletResponse response,
  FilterChain chain) throws IOException, ServletException
 {
 HttpServletRequest httpreq = (HttpServletRequest) request;
  if (httpreq.getMethod().equals("POST"))
 {
 request.setCharacterEncoding(encoding);
 } else
  {
 request = new Request(httpreq);
 }
 chain.doFilter(request, response);
  }

 public void init(FilterConfig filterConfig) throws ServletException
 {
 encoding = filterConfig.getInitParameter("encoding");
 }
}

配置web.xml：

 <!-- URL中文字符编码过滤器 -->
 <filter>
  <filter-name>CharsetEncodingFilter</filter-name>
  <filter-class>com.rzq.basePro.web.filter.CharsetAllEncodingFilter</filter-class>
  <init-param>
 <param-name>encoding</param-name>
 <param-value>UTF-8</param-value>
 </init-param>
 </filter> 
  <filter-mapping>
  <filter-name>CharsetEncodingFilter</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>