解决tomcat7中request会对中文重新编码，导致后台接收到为encode编码后参数问题

package xxx;import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
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 SetCharacterEncodingFilter implements Filter{
String encoding = null;
FilterConfig filterConfig = null;/** 初始化方法 */
public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig = filterConfig;
this.encoding = filterConfig.getInitParameter("encoding");
}/** 过滤处理方法 */
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
if (encoding!=null){
//对请求进行编码设置
request.setCharacterEncoding(encoding);
HttpServletRequest httprequest=(HttpServletRequest) request;
if(httprequest.getMethod().equalsIgnoreCase("get")){
MyRequest myRequest = new MyRequest(httprequest);
myRequest.setEncoding(encoding); chain.doFilter(myRequest, response);
}else{
//将处理权转交给下一个处理器
chain.doFilter(request,response);
}
}else{
//将处理权转交给下一个处理器
chain.doFilter(request,response);
}
}/**
* Wrapper包装类，装饰设计模式,内部有个真实对象的引用
*/
class MyRequest extends HttpServletRequestWrapper{
private HttpServletRequest request;
private String encoding; public MyRequest(HttpServletRequest request) {
super(request);
this.request = request;
} public void setEncoding(String encoding) {
this.encoding = encoding;
} @Override
//重写父类的方法
public String getParameter(String name) {
String[] p = getParameterMap().get(name);
if(p!=null&&p.length>0){
return p[0];
}else{
return null;
}
} @Override
//获取参数的方法
public Map<String, String[]> getParameterMap() {
//获取客户端传过来的参数数据，并且包装成一个Map集合
Map<String, String[]> resMap = new HashMap<String, String[]>();
Map map = request.getParameterMap();
Set set = map.keySet();
Iterator it = set.iterator();
while(it.hasNext()){
String key=(String) it.next();
Object value= map.get(key);
if(value instanceof String[]){
String[] values=(String[]) value;
for(int i=0;i<values.length;i++){
try {
values[i] = java.net.URLDecoder.decode(values[i], encoding);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} //翻页参数中的中文解码，编码在dbpage.java中进行的
} resMap.put(key, values);
}
}
return resMap;
}
}/** 销毁方法 */
public void destroy() {
this.encoding = null;
this.filterConfig = null;
}}