附：SetCharacterEncodingFilter源文件 package org.kyle.web.sample; 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; import javax.servlet.UnavailableException; public class SetCharacterEncodingFilter implements Filter { /** * 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 {
// 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 * *encoding * UTF-8 * */ 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; }
/** * Select an appropriate character encoding to be used, based on the * characteristics of the current request and/or filter initialization * parameters. If no character encoding should be set, return * null. *
* The default implementation unconditionally returns the value configured * by the encoding initialization parameter for this * filter. * * @param request The servlet request we are processing */ protected String selectEncoding(ServletRequest request) { return (this.encoding); } }
