Spring MVC使用@ResponseBody后会产生很大的响应头(Accept-Charset会达到4K+),原因在于默认情况下StringHttpMessageConverter.writeInternal()会将所有可用字符集回写到response响应头中:

去除这些信息我们可以这样,定义一个拦截器:

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package cn.krun.cup.pojo;
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;
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;
}
}
}

然后在spring中配置

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<mvc:annotation-driven>
<mvc:message-converters>
<bean class="cn.krun.cup.pojo.UTF8StringHttpMessageConverter">
<property name="writeAcceptCharset" value="false">
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>

Done!