charSetFilter

package com.accp.fifthlygroup.common;

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;


/**
* Servlet Filter implementation class CharSetFilter
*/
public class CharSetFilter implements Filter {

    /**
     * Default constructor.
     */
    public CharSetFilter() {
        // TODO Auto-generated constructor stub
    }

/**
* @see Filter#destroy()
*/
public void destroy() {
// TODO Auto-generated method stub
}

/**
* @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
*/
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
HttpServletRequest httpReq = (HttpServletRequest)request;
if(httpReq.getMethod().equalsIgnoreCase("GET")){
request = new MyRequest(httpReq);
}else{
request.setCharacterEncoding("UTF-8");
}

/*设置编码*/
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
// pass the request along the filter chain
chain.doFilter(request, response);
}

/**
* @see Filter#init(FilterConfig)
*/
public void init(FilterConfig fConfig) throws ServletException {
// TODO Auto-generated method stub
}




/**
* 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 MyRequest extends HttpServletRequestWrapper{
private String encode = "UTF-8";
public MyRequest(HttpServletRequest request) {
super(request);
}

/**
* 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encode.
*/
public String toChi(String input){
if(input==null){
return null;
}else{
try {
byte [] bytes = input.getBytes("ISO8859-1");
return new String(bytes,encode);
//return new String(input.getBytes("ISO-8859-1"));
} catch (Exception e) {

}
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;
}
}

}