Sping MVC 的 @ResponseBody 乱码问题的完美解决

关于Sping MVC  的   @ResponseBody  乱码问题的完美解决

重写了StringHttpMessageConverter 类，如下 

package org.springframework.http.converter;

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.util.FileCopyUtils;

/**
 * 通过重写解决了乱码问题
 * 
 * @author jiulong_ck
 * 
 */
public class StringHttpMessageConverter extends AbstractHttpMessageConverter<String> {
	public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");  //  在这里先写好自己使用的默认编码
	private final List<Charset> availableCharsets;
	private boolean writeAcceptCharset = true;

	public StringHttpMessageConverter() {
		super(new MediaType[] { new MediaType("text", "plain", DEFAULT_CHARSET), MediaType.ALL });
		this.availableCharsets = new ArrayList(Charset.availableCharsets().values());
	}

	public void setWriteAcceptCharset(boolean writeAcceptCharset) {
		this.writeAcceptCharset = writeAcceptCharset;
	}

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

	protected String readInternal(Class clazz, HttpInputMessage inputMessage) throws IOException {
		Charset charset = getContentTypeCharset(inputMessage.getHeaders().getContentType());
		return FileCopyUtils.copyToString(new InputStreamReader(inputMessage.getBody(), charset));
	}

	protected Long getContentLength(String s, MediaType contentType) {
		Charset charset = getContentTypeCharset(contentType);
		try {
			return Long.valueOf(s.getBytes(charset.name()).length);
		} catch (UnsupportedEncodingException ex) {
			throw new InternalError(ex.getMessage());
		}

	}

	protected void writeInternal(String s, HttpOutputMessage outputMessage) throws IOException {
		if (this.writeAcceptCharset) {
			outputMessage.getHeaders().setAcceptCharset(getAcceptedCharsets());
		}

		// 重新定义 MediaType ，解决乱码
		/****************************/
		MediaType contentType = outputMessage.getHeaders().getContentType();
		Charset contentTypeCharset = getContentTypeCharset(contentType);
		contentType = new MediaType(contentType.getType(), contentType.getSubtype(), contentTypeCharset);
		outputMessage.getHeaders().setContentType(contentType);
		/****************************/
		
		Charset charset = getContentTypeCharset(outputMessage.getHeaders().getContentType());
		FileCopyUtils.copy(s, new OutputStreamWriter(outputMessage.getBody(), charset));
	}

	protected List<Charset> getAcceptedCharsets() {
		return this.availableCharsets;
	}

	private Charset getContentTypeCharset(MediaType contentType) {

		if ((contentType != null) && (contentType.getCharSet() != null)) {
			return contentType.getCharSet();
		}

		return DEFAULT_CHARSET;
	}
}