org.apache.wicket.request.handler.TextRequestHandler.java Source code

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Here is the source code for org.apache.wicket.request.handler.TextRequestHandler.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.wicket.request.handler;

import java.io.IOException;
import java.nio.charset.Charset;

import org.apache.wicket.request.IRequestCycle;
import org.apache.wicket.request.IRequestHandler;
import org.apache.wicket.request.http.WebResponse;
import org.apache.wicket.util.lang.Args;
import org.apache.wicket.util.string.Strings;

/**
 * Request target that responds by sending its string property.
 * 
 * @author igor.vaynberg
 * @author Eelco Hillenius
 */
public class TextRequestHandler implements IRequestHandler {
    /** the string for the response. */
    private final String string;

    /** content type for the string */
    private final String contentType;

    /** charset of the string */
    private final String encoding;

    /**
     * Creates a string request target with content type <code>text/plain</code> and default charset
     * (usually UTF-8)
     * 
     * @param string
     *            the string for the response
     */
    public TextRequestHandler(final String string) {
        this("text/plain", null, string);
    }

    /**
     * Constructor
     * 
     * @param contentType
     *            content type of the data the string represents, e.g.
     *            <code>text/html; charset=utf-8</code>
     * @param encoding
     *            charset to use
     * @param string
     *            string for the response
     */
    public TextRequestHandler(final String contentType, final String encoding, final String string) {
        this.contentType = Args.notEmpty(contentType, "contentType");
        this.string = Args.notNull(string, "string");
        this.encoding = encoding;
    }

    /**
     * Responds by sending the string property.
     * 
     * @see org.apache.wicket.request.IRequestHandler#respond(org.apache.wicket.request.IRequestCycle)
     */
    @Override
    public void respond(final IRequestCycle requestCycle) {
        String encoding = getEncoding(requestCycle);

        // Get servlet response to use when responding with resource
        final WebResponse response = (WebResponse) requestCycle.getResponse();
        response.setContentType(contentType + ";charset=" + encoding);

        // send string to client
        try {
            byte[] bytes = string.getBytes(encoding);
            response.setContentLength(bytes.length);
            response.write(bytes);
        } catch (IOException e) {
            throw new RuntimeException("Unable to render string: " + e.getMessage(), e);
        }
    }

    /**
     * @param requestCycle
     * @return the configured encoding or the request's one as default
     */
    private String getEncoding(final IRequestCycle requestCycle) {
        String encoding = this.encoding;
        if (Strings.isEmpty(encoding)) {
            Charset charset = requestCycle.getRequest().getCharset();
            if (charset != null) {
                encoding = charset.name();
            }
        }
        return encoding;
    }

    /**
     * Gets the string property.
     * 
     * @return the string property
     */
    public String getString() {
        return string;
    }

}