Servlet過濾器---編碼轉換過濾器

該實例用於將請求與相應的編碼設置為當前網站的默認編碼

java類：

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 EncodingFilter implements Filter {
    
    private String charEncoding = null;

    public EncodingFilter() {
    }

    /**
     * @see Filter#init(FilterConfig)
     */
    public void init(FilterConfig fConfig) throws ServletException {
        charEncoding = fConfig.getInitParameter("charEncoding");
        if (charEncoding == null || charEncoding.equals("null")) {
            throw new ServletException("EncodingFilter中的編碼設置為空");
        }
    }

    /**
     * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
     */
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        // 將設置的編碼與請求的編碼進行比較，若不同，則將請求的編碼設置為設置的編碼
        if (!charEncoding.equals(request.getCharacterEncoding())) {
            request.setCharacterEncoding(charEncoding);
        }
        // 將相應的編碼設置為設置的編碼
        response.setCharacterEncoding(charEncoding);
        chain.doFilter(request, response);
        
    }

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

web.xml：

<filter>
      <filter-name>encodingFilter</filter-name>
      <filter-class>com.hudongwu.filter.EncodingFilter</filter-class>
      <init-param>
          <param-name>charEncoding</param-name>
          <param-value>UTF-8</param-value>
      </init-param>
  </filter>
  <filter-mapping>
      <filter-name>encodingFilter</filter-name>
      <url-pattern>/*</url-pattern>
  </filter-mapping>

 Servlet過濾器---目錄