com.facetime.cloud.server.support.UTF8HttpMessageConverter.java Source code

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Here is the source code for com.facetime.cloud.server.support.UTF8HttpMessageConverter.java

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/*
 * Copyright 2002-2010 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.facetime.cloud.server.support;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.AbstractHttpMessageConverter;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.util.FileCopyUtils;

/**
 * Implementation of {@link HttpMessageConverter} that can read and write strings.
 *
 * <p>By default, this converter supports all media types (<code>&#42;&#47;&#42;</code>), and writes with a {@code
 * Content-Type} of {@code text/plain}. This can be overridden by setting the {@link
 * #setSupportedMediaTypes(java.util.List) supportedMediaTypes} property.
 *
 * @author Arjen Poutsma
 * @since 3.0
 */
public class UTF8HttpMessageConverter extends AbstractHttpMessageConverter<String> {

    public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");

    /**  */
    private static final MediaType UTF_8_MEDIA_TYPE = new MediaType("text", "plain", DEFAULT_CHARSET);

    private final List<Charset> availableCharsets;

    private boolean writeAcceptCharset = true;

    public UTF8HttpMessageConverter() {
        super();
        this.availableCharsets = new ArrayList<Charset>(Charset.availableCharsets().values());
    }

    /**
     * Indicates whether the {@code Accept-Charset} should be written to any outgoing request.
     * <p>Default is {@code true}.
     */
    public void setWriteAcceptCharset(boolean writeAcceptCharset) {
        this.writeAcceptCharset = writeAcceptCharset;
    }

    @Override
    public boolean supports(Class<?> clazz) {
        return String.class.equals(clazz);
    }

    @Override
    protected String readInternal(@SuppressWarnings("rawtypes") Class clazz, HttpInputMessage inputMessage)
            throws IOException {
        MediaType contentType = inputMessage.getHeaders().getContentType();
        Charset charset = contentType.getCharSet() != null ? contentType.getCharSet() : DEFAULT_CHARSET;
        return FileCopyUtils.copyToString(new InputStreamReader(inputMessage.getBody(), charset));
    }

    @Override
    protected Long getContentLength(String s, MediaType contentType) {
        if (contentType != null && contentType.getCharSet() != null) {
            Charset charset = contentType.getCharSet();
            try {
                return (long) s.getBytes(charset.name()).length;
            } catch (UnsupportedEncodingException ex) {
                // should not occur
                throw new InternalError(ex.getMessage());
            }
        } else {
            return null;
        }
    }

    @Override
    protected void writeInternal(String s, HttpOutputMessage outputMessage) throws IOException {
        HttpHeaders headers = outputMessage.getHeaders();
        if (!"UTF-8".equalsIgnoreCase(headers.getContentType().getCharSet().displayName())) {
            headers.setContentType(UTF_8_MEDIA_TYPE);
        }

        if (writeAcceptCharset) {
            headers.setAcceptCharset(getAcceptedCharsets());
        }
        MediaType contentType = outputMessage.getHeaders().getContentType();
        Charset charset = contentType.getCharSet() != null ? contentType.getCharSet() : DEFAULT_CHARSET;
        FileCopyUtils.copy(s, new OutputStreamWriter(outputMessage.getBody(), charset));
    }

    /**
     * Return the list of supported {@link Charset}.
     *
     * <p>By default, returns {@link Charset#availableCharsets()}. Can be overridden in subclasses.
     *
     * @return the list of accepted charsets
     */
    protected List<Charset> getAcceptedCharsets() {
        return this.availableCharsets;
    }

}