Spring3 MVC使用@ResponseBody后会产生非常大的响应头(Accept-Charset会达到4K+)。原因在于默认情况下StringHttpMessageConverter.writeInternal()会将全部可用字符集回写到response响应头中：问题来了

解决方案：

一般我们都会重写springs mvc的HttpMessageConverter。改为utf-8编码：

package com.goldpalm.core.spring.mvc;

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.HttpInputMessage;

import org.springframework.http.HttpOutputMessage;

import org.springframework.http.MediaType;

import org.springframework.http.converter.AbstractHttpMessageConverter;

import org.springframework.util.FileCopyUtils;

/**

 * 重写SpringMVC的字符串转换器。使用UTF-8编码

 * @since 2012-7-5 下午2:28:19

 * @author Jesse Lu

 */

public class UTF8StringHttpMessageConverter extends AbstractHttpMessageConverter<String> {

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

    private final List<Charset> availableCharsets;

    private boolean writeAcceptCharset = true;

    public UTF8StringHttpMessageConverter() {

        super(new MediaType("text", "plain", DEFAULT_CHARSET), MediaType.ALL);

        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);

    }

    @SuppressWarnings("rawtypes")

    @Override

    protected String readInternal(Class clazz, HttpInputMessage inputMessage) throws IOException {

        Charset charset = getContentTypeCharset(inputMessage.getHeaders().getContentType());

        return FileCopyUtils.copyToString(new InputStreamReader(inputMessage.getBody(), charset));

    }

    @Override

    protected Long getContentLength(String s, MediaType contentType) {

        Charset charset = getContentTypeCharset(contentType);

        try {

            return (long) s.getBytes(charset.name()).length;

        } catch (UnsupportedEncodingException ex) {

            // should not occur

            throw new InternalError(ex.getMessage());

        }

    }

    @Override

    protected void writeInternal(String s, HttpOutputMessage outputMessage) throws IOException {

        if (writeAcceptCharset) {

            outputMessage.getHeaders().setAcceptCharset(getAcceptedCharsets());

        }

        Charset charset = getContentTypeCharset(outputMessage.getHeaders().getContentType());

        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;

    }

    private Charset getContentTypeCharset(MediaType contentType) {

        if (contentType != null && contentType.getCharSet() != null) {

            return contentType.getCharSet();

        } else {

            return DEFAULT_CHARSET;

        }

    }

}

在xm中配置：注意红色圈起来的配置

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<mvc:annotation-driven>

		<mvc:message-converters>

			<bean class="com.goldpalm.core.spring.mvc.UTF8StringHttpMessageConverter">

				<property name="writeAcceptCharset" value="false" />

			</bean>

		</mvc:message-