com.investdata.common.filter.CharacterEncodingFilter.java Source code

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Here is the source code for com.investdata.common.filter.CharacterEncodingFilter.java

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/*
 * Copyright 2002-2007 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.investdata.common.filter;

import java.io.IOException;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.springframework.util.ClassUtils;
import org.springframework.web.filter.OncePerRequestFilter;

/**
 * Servlet 2.3/2.4 Filter that allows one to specify a character encoding for
 * requests. This is useful because current browsers typically do not set a
 * character encoding even if specified in the HTML page or form.
 *
 * <p>This filter can either apply its encoding if the request does not
 * already specify an encoding, or enforce this filter's encoding in any case
 * ("forceEncoding"="true"). In the latter case, the encoding will also be
 * applied as default response encoding on Servlet 2.4+ containers (although
 * this will usually be overridden by a full content type set in the view).
 *
 */
public class CharacterEncodingFilter extends OncePerRequestFilter {
    private Logger log = Logger.getLogger(CharacterEncodingFilter.class);

    // Determine whether the Servlet 2.4 HttpServletResponse.setCharacterEncoding(String)
    // method is available, for use in the "doFilterInternal" implementation.
    private final static boolean setCharacterEncodingAvailable = ClassUtils.hasMethod(HttpServletResponse.class,
            "setCharacterEncoding", new Class[] { String.class });

    private String encoding;

    private boolean forceEncoding = false;

    private String gbkEncodingUrl;

    public void setGbkEncodingUrl(String gbkEncodingUrl) {
        this.gbkEncodingUrl = gbkEncodingUrl;
    }

    /**
     * Set the encoding to use for requests. This encoding will be passed into a
     * {@link javax.servlet.http.HttpServletRequest#setCharacterEncoding} call.
     * <p>Whether this encoding will override existing request encodings
     * (and whether it will be applied as default response encoding as well)
     * depends on the {@link #setForceEncoding "forceEncoding"} flag.
     */
    public void setEncoding(String encoding) {
        this.encoding = encoding;
    }

    /**
     * Set whether the configured {@link #setEncoding encoding} of this filter
     * is supposed to override existing request and response encodings.
     * <p>Default is "false", i.e. do not modify the encoding if
     * {@link javax.servlet.http.HttpServletRequest#getCharacterEncoding()}
     * returns a non-null value. Switch this to "true" to enforce the specified
     * encoding in any case, applying it as default response encoding as well.
     * <p>Note that the response encoding will only be set on Servlet 2.4+
     * containers, since Servlet 2.3 did not provide a facility for setting
     * a default response encoding.
     */
    public void setForceEncoding(boolean forceEncoding) {
        this.forceEncoding = forceEncoding;
    }

    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
            FilterChain filterChain) throws ServletException, IOException {

        if (this.encoding != null && (this.forceEncoding || request.getCharacterEncoding() == null)) {
            request.setCharacterEncoding(this.encoding);//?  
            if (this.forceEncoding) {
                response.setCharacterEncoding(this.encoding);
            }
        }
        filterChain.doFilter(request, response);//  

        /*
        if (this.encoding != null && (this.forceEncoding || request.getCharacterEncoding() == null)) {
           request.setCharacterEncoding(this.encoding);
           if (this.forceEncoding && setCharacterEncodingAvailable) {
        response.setCharacterEncoding(this.encoding);
           }
        }
        filterChain.doFilter(request, response);
        */
    }

}