SpringMVC的@ResponseBody註解可以將請求方法返回的對象直接轉換成JSON對象，但是當返回值是String的時候，中文會亂碼。
原因是因爲其中字符串轉換和對象轉換用的是兩個轉換器，而String的轉換器中固定了轉換編碼爲"ISO-8859-1"
在網上查詢了一下解決辦法：
解決辦法：
1.返回字符串時，將字符串結果轉
return new String("你好".getBytes(), "ISO-8859-1");
//注意這種返回到前端的編碼是ISO-8859-1，對於需要utf-8的不行。
2.添加@RequestMapping註解，配置produces的值
@RequestMapping(value = "/add", produces = {"application/json;charset=UTF-8"})
3.StringHttpMessageConverter重寫
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);
}
@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;
}
}
}
配置文件：
<mvc:annotation-driven>
<mvc:message-converters>
<bean class="xx.xx.xx.UTF8StringHttpMessageConverter" />
</mvc:message-converters>
</mvc:annotation-driven>
重點：成功的解決辦法
最後，我自己親自測試了，自用將<mvc:annotation-driven />放在
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">之後即可，也沒有重寫StringHttpMessageConverter
附上我的配置：
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
<property name="messageConverters">
<list>
<ref bean="stringHttpMessageConverter" />
<ref bean="mappingJacksonHttpMessageConverter" />
</list>
</property>
</bean>
<!-- 默認的註解映射的支持,注意這個必須放在RequestMappingHandlerAdapter之後 -->
<mvc:annotation-driven />
<bean id="stringHttpMessageConverter" class="org.springframework.http.converter.StringHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>text/plain;charset=UTF-8</value>
<value>text/html;charset=UTF-8</value>
</list>
</property>
</bean>
<bean id="mappingJacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>application/json;charset=UTF-8</value>
<value>text/html;charset=UTF-8</value>
</list>
</property>
</bean>