setencodingfilter.java

一个基于Struts架构

package Encode;


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;


/**
 * 过滤字符集
 *
 */
public class SetEncodingFilter implements Filter {
//	private static Session session;


  /**
   * The default character encoding to set for requests that pass through
   * this filter.
   */
  protected String encoding = null;

  /**
   * The filter configuration object we are associated with.  If this value
   * is null, this filter instance is not currently configured.
   */
  protected FilterConfig filterConfig = null;

  /**
   * Should a character encoding specified by the client be ignored?
   */
  protected boolean ignore = true;

  /**
   * Take this filter out of service.
   */
  public void destroy() {
    this.encoding = null;
    this.filterConfig = null;

  }

  /**
   * Select and set (if specified) the character encoding to be used to
   * interpret request parameters for this request.
   *
   * @param request The servlet request we are processing
   * @param result The servlet response we are creating
   * @param chain The filter chain we are processing
   *
   * @exception IOException if an input/output error occurs
   * @exception ServletException if a servlet error occurs
   */
  public void doFilter( ServletRequest request,
                                        ServletResponse response,
                                        FilterChain chain) throws IOException, ServletException {

    if (ignore || (request.getCharacterEncoding() == null)) {
        request.setCharacterEncoding(selectEncoding(request));
    }

    chain.doFilter(request, response);

  }

  /**
   * Place this filter into service.
   * @param filterConfig The filter configuration object
   */
  public void init(FilterConfig filterConfig) throws ServletException {

        this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");
        String value = filterConfig.getInitParameter("ignore");

        if (value == null)
          this.ignore = true;
        else if (value.equalsIgnoreCase("true") || value.equalsIgnoreCase("yes"))
          this.ignore = true;
        else
          this.ignore = false;

 }


  protected String selectEncoding(ServletRequest request) {
    return (this.encoding);
  }

  /**
   * Returns the filterConfig.
   * @return FilterConfig
   */
  public FilterConfig getFilterConfig() {
    return filterConfig;
  }

  /**
   * Sets the filterConfig.
   * @param filterConfig The filterConfig to set
   */
  public void setFilterConfig(FilterConfig filterConfig) {
    this.filterConfig = filterConfig;
  }

}