javaweb 使用过滤器解决全站编码问题

最新推荐文章于 2022-05-18 22:32:14 发布

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本文介绍了一种通过实现Servlet Filter来解决HTTP请求中字符编码问题的方法，特别针对GET和POST请求进行了UTF-8编码处理，确保了客户端与服务器间的数据正确传输。

Filter过滤器的代码

package cn.yellowimg.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.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;

/**
 * Servlet Filter implementation class EncodingFilter
 */
 //过滤全站
@WebFilter("/*")
public class EncodingFilter implements Filter {


public void destroy() {

}

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

    HttpServletRequest rq = (HttpServletRequest)request;
    //解决post编码问题
    if(rq.getMethod().equals("POST"))
    {
        rq.setCharacterEncoding("utf-8");
        chain.doFilter(rq, response);
    }
    //解决get编码问题
    else {
        //调包request 装饰者模式
        EncodingRequest eq = new EncodingRequest(rq);
        chain.doFilter(eq, response);
    }
}
public void init(FilterConfig fConfig) throws ServletException {
}
}

调包request（即增强request中的getParameter()方法）

package cn.yellowimg.filter;

import java.io.UnsupportedEncodingException;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

//继承tomcat提供的HttpServletRequestWrapper，增强request
public class EncodingRequest extends HttpServletRequestWrapper {
HttpServletRequest httpServletRequest;

public EncodingRequest(HttpServletRequest request) {
    super(request);
    this.httpServletRequest = request;
}

@Override
//重写getParameter方法，将iso-8859-1专成utf-8编码
public String getParameter(String name) {

    String value = super.getParameter(name);

    try {
        value = new String(value.getBytes("iso-8859-1"), "utf-8");
    } catch (UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return value;
}
}