setcharacterencodingfilter.java

ext2+spring+hibernate+dwr做的小系统

package com.newsoft.util;

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 SetCharacterEncodingFilter implements Filter {
	// ----------------------------------------------------- Instance Variables
	/**
	 * 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;
	// --------------------------------------------------------- Public Methods
	/**
	 * Take this filter out of service.
	 */
	public void destroy() {
		this.encoding = null;
		this.filterConfig = null;
	}

	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		// Conditionally select and set the character encoding to be used
		if (ignore || (request.getCharacterEncoding() == null)) {
			String encoding = selectEncoding(request);
			if (encoding != null) request.setCharacterEncoding(encoding);
		}
		// Pass control on to the next filter
		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")) this.ignore = true;
		else if (value.equalsIgnoreCase("yes")) this.ignore = true;
		else this.ignore = false;
	}

	// ------------------------------------------------------ Protected Methods
	protected String selectEncoding(ServletRequest request) {
		return (this.encoding);

	}

}