encodingfilter.java

一个基于Java的新闻发布系统

/*
 *
 * Title: The ERP System of kelamayi Downhole Company [PMIP]
 *
 * Copyright: Copyright (c) 2004
 *
 * Company: westerasoft Co., Ltd
 *
 * All right reserved.
 *
 * Created on 2004-4-8
 *
 * JDK version used		:1.4.1
 *
 * Modification history:
 *
 */

package com.hope.common.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;

/**
 * 设置字符集过滤
 * @version Version 1.0 <br/>
 * @author 刘宏德
 */
public class EncodingFilter
	implements Filter {
  /**
   * 字符编码集
   */
  protected String encoding = null;

  /**
   * 过滤器配置对象
   */
  protected FilterConfig filterConfig = null;

  /**
   * 取消过滤标志
   */
  protected boolean ignore = true;

  /**
   * 注销filter服务
   */
  public void destroy() {
	this.encoding = null;
	this.filterConfig = null;
  }

  /**
   * 获取设定的字符集，对request中的参数进行字符集设定
   *
   * @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);
 }

  /**
   * 初始化Filter参数
   * @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;
  }

  /**
   * 获取用户设定的字符集，如没有设定，返回null。
   *
   * @param request The servlet request we are processing
   */
  protected String selectEncoding(ServletRequest request) {
	return (this.encoding);
  }

  /**
   * 返回FilterConfig对象。
   * @return FilterConfig
   */
  public FilterConfig getFilterConfig() {
	return filterConfig;
  }

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

}