java中用過濾器解決字符編碼問題

java中用過濾器解決字符編碼問題

java的web程序經常出現中文亂碼的問題，用一個實現了Filter接口的過濾器類可以較好地解決這個問題。

新增過濾器類EncodingFilter

import java.io.IOException;
import javax.servlet.*;

public class EncodingFilter implements Filter {

    private FilterConfig filterConfig = null;
    private String encoding = null;

     @Override
    public void destroy() {
         filterConfig = null;
         encoding = null;
     }

     @Override
    public void doFilter(ServletRequest request, ServletResponse response,
             FilterChain filterChain) throws IOException, ServletException {
        if (request.getCharacterEncoding() == null) {
            if (encoding != null) {
                 request.setCharacterEncoding(encoding);
             }
             filterChain.doFilter(request, response);
         }
     }

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

web.xml中加入

  <filter>
      <filter-name>EncodingFilter</filter-name>
      <filter-class>EncodingFilter</filter-class>
      <init-param>
          <param-name>encoding</param-name>
          <param-value>UTF-8</param-value>
      </init-param>
  </filter>
  <filter-mapping>
      <filter-name>EncodingFilter</filter-name>
      <url-pattern>/*</url-pattern>
  </filter-mapping>

jsp頁面中設置pageEncoding="UTF-8" ，表單提交方法method="post"