过滤器实现字符编码

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CharactorFilter

package com.baozi;

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;

public class CharactorFilter implements Filter {
    private String encoding=null;
    public void init(FilterConfig fConfig) throws ServletException {
        encoding=fConfig.getInitParameter("encoding");
    }
    public CharactorFilter() {
        // TODO Auto-generated constructor stub
    }
    public void destroy() {
        encoding=null;
    }
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        request.setCharacterEncoding(encoding);
        response.setContentType("text/html;charset="+encoding);
        chain.doFilter(request, response);
    }
}

AddServlet

package com.baozi;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class AddServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    public AddServlet() {
        super();
        // TODO Auto-generated constructor stub
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request,response);
    }
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        PrintWriter out=response.getWriter();
        String id=request.getParameter("id");
        String name=request.getParameter("name");
        String author=request.getParameter("author");
        String price=request.getParameter("price");
        out.print("<h2>图书信息添加成功</h2><hr>");
        out.print("图书编号:"+id+"<br>图书名称:"+name+"<br>图书作者:"+author+"<br> 图书价格:"+price);   
    }

}