package gboat2.base.plugin.servlet.filter;
   
   import static gboat2.base.bridge.GboatAppConstants.ENCODING_ISO88591;
   import static gboat2.base.bridge.GboatAppConstants.ENCODING_UTF8;
   
   import java.io.IOException;
   import java.net.URLDecoder;
   import java.util.ArrayList;
   import java.util.Collection;
  import java.util.Iterator;
  
  import javax.servlet.FilterChain;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.web.filter.OncePerRequestFilter;
  
  /**
   * 处理请求编码的过滤器，解决 get 方式提交乱码问题。<br>
   * 在 web.xml 中添加如下配置启用该过滤器：
   * <pre><code>
   * &lt;!-- 编码过滤器 --&gt;
   * &lt;filter&gt;
   *     &lt;filter-name&gt;gboat2EncodingFilter&lt;/filter-name&gt;
   *     &lt;filter-class&gt;gboat2.base.plugin.servlet.filter.GboatEncodingFilter&lt;/filter-class&gt;
   * &lt;/filter&gt;
   * &lt;filter-mapping&gt;
   *     &lt;filter-name&gt;gboat2EncodingFilter&lt;/filter-name&gt;
   *     &lt;url-pattern&gt;*.do&lt;/url-pattern&gt;
   * &lt;/filter-mapping&gt;
   * </code></pre>
   * @date 2012-4-17
   * @author zhangxj-a
   * @since 1.0
   */
  public class GboatEncodingFilter extends OncePerRequestFilter {
  
      private Logger logger = LoggerFactory.getLogger(GboatEncodingFilter.class.getName());
  
      @Override
      protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
              throws ServletException, IOException {
          HttpServletRequest httpServletRequest = (HttpServletRequest) request;
          request.setCharacterEncoding(ENCODING_UTF8);
  
          ArrayList<String> queryValues = new ArrayList<String>();
          String query = httpServletRequest.getQueryString();
          if (query != null) {
              String[] expressions = query.split("&");
              for (String expression : expressions) {
                  String[] parts = expression.split("=");
                  if (parts.length == 2) {
                      String str = URLDecoder.decode(parts[1], ENCODING_UTF8);
                      queryValues.add(new String(str.getBytes(ENCODING_UTF8), ENCODING_ISO88591));
                      logger.debug(" request get parameter query key : {},value : {}", parts[0], str);
                  }
              }
          }
  
          Collection<?> values = request.getParameterMap().values();
          for (Iterator<?> iterator = values.iterator(); iterator.hasNext();) {
              String[] strs = (String[]) iterator.next();
              for (int i = 0; i < strs.length; i++) {
                  for (String qStr : queryValues) {
                      if (qStr.equals(strs[i])) {
                          strs[i] = new String(qStr.getBytes(ENCODING_ISO88591), ENCODING_UTF8);
                          break;
                      }
                  }
              }
          }
  
          filterChain.doFilter(request, response);
      }
  }