SpringMVC 中文乱码

乱码分为多种情况，本文介绍两种常见的乱码现象和解决办法
1.@ResponseBody返回数据乱码
SpringMVC @ResponseBody默认情况下返回中文为乱码，原因是@ResponseBody采用的是
StringHttpMessageConverter，而它采用的是ISO-8859-1编码。

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

    public static final Charset DEFAULT_CHARSET = Charset.forName("ISO-8859-1");


    private final Charset defaultCharset;

    private final List<Charset> availableCharsets;

    private boolean writeAcceptCharset = true;

乱码问题有两种解决方案：
1.1局部解决方案
在@RequestMapping中声明produces

@ResponseBody
@RequestMapping(value = "/login",method = RequestMethod.POST,produces = "text/html;charset=UTF-8")

该方案只对已配置的请求生效，要全局生效需要采用方案二
1.2全局解决方案
在SpringMVC.xml中配置,可以从StringHttpMessageConverter源码中看出，需要配置supportedMediaTypes

    <mvc:annotation-driven>
        <mvc:message-converters>
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <property name="supportedMediaTypes" value="text/html;charset=UTF-8"/>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

2.jsp传入参数乱码
2.1解决办法，在web.xml中加入编码过滤器

    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>