SpringMvc中json转换

方案一：使用阿里巴巴fastjson

1、pom.xml中添加依赖

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.1.27</version>
</dependency>

2、viewspace-servlet.xml

<bean id="jsonConverter" class="com.sunsharing.springdemo.utils.MappingFastJsonHttpMessageConverter">
        <property name="supportedMediaTypes" value="application/json" />
        <property name="serializerFeature" >
            <list>
                <value>WriteMapNullValue</value>
                <value>QuoteFieldNames</value>
            </list>
        </property>
    </bean>
    
    <bean class ="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" >
       <property name="messageConverters">
           <list>
               <ref bean="jsonConverter" />
           </list>
       </property>
   </bean>

在整个过程中花了比较多的时间解决中文乱码，最后发现在

org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter

这个bean重复配置，导致编码没有被重置成utf-8,值得自己深深的反思.

另一方面，Spring3.0 MVC @ResponseBody 的作用是把返回值直接写到HTTP response body里，org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter使用了org.springframework.进行处理，里面的源码默认使用的是“ISO-8859-1”，org.springframework.中的getDefaultContentType方法是可以重写的，所以下面的工具类MappingFastJsonHttpMessageConverter 中 DEFAULT_CHARSET 改成utf-8后重写即可。

3、Controller层关键代码

@RequestMapping(value = "/jsondata")
@ResponseBody
  public String getGonganList( HttpServletResponse response){
  // response.setContentType("application/json; charset=utf-8");
   List<Gongandanwei> gongandanwei=gongandanweiService.getAllGongandanwei();
    
    String jsonString = JSON.toJSONString(gongandanwei);
    System.out.println(jsonString);
    return jsonString;
}

4、jsp页面

<script  type="text/javascript"   >
   $(document).ready(function(){$.ajax({
    url: "<%=context%>/jsondata.html",
    type : "POST",
    success: function(data){
        console.info(JSON.stringify(data));
    alert(data);  },
    dataType:"json"});
  });
</script>

5、解决中文乱码的工具类

package com.sunsharing.springdemo.utils;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.Charset;

import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.AbstractHttpMessageConverter;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.converter.HttpMessageNotWritableException;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializerFeature;

/**
 * Created by nyp on 2015/2/13.
 */
public class MappingFastJsonHttpMessageConverter extends AbstractHttpMessageConverter<Object> {

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

    // fastjson特性参数
    private SerializerFeature[] serializerFeature;

    public SerializerFeature[] getSerializerFeature() {
        return serializerFeature;
    }

    public void setSerializerFeature(SerializerFeature[] serializerFeature) {
        this.serializerFeature = serializerFeature;
    }

    public MappingFastJsonHttpMessageConverter() {
        super(new MediaType("application", "json", DEFAULT_CHARSET));
    }

    @Override
    public boolean canRead(Class<?> clazz, MediaType mediaType) {
        // JavaType javaType = getJavaType(clazz);
        // return this.objectMapper.canDeserialize(javaType) &&
        // canRead(mediaType);
        return true;
    }

    @Override
    public boolean canWrite(Class<?> clazz, MediaType mediaType) {
        // return this.objectMapper.canSerialize(clazz) && canWrite(mediaType);
        return true;
    }

    @Override
    protected boolean supports(Class<?> clazz) {
        // should not be called, since we override canRead/Write instead
        throw new UnsupportedOperationException();
    }

    @Override
    protected Object readInternal(Class<?> clazz, HttpInputMessage inputMessage)
            throws IOException, HttpMessageNotReadableException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        int i;
        while ((i = inputMessage.getBody().read()) != -1) {
            baos.write(i);
        }
        return JSON.parseArray(baos.toString(), clazz);
    }

    @Override
    protected void writeInternal(Object o, HttpOutputMessage outputMessage)
            throws IOException, HttpMessageNotWritableException {
        String jsonString = JSON.toJSONString(o, serializerFeature);
        OutputStream out = outputMessage.getBody();
        out.write(jsonString.getBytes(DEFAULT_CHARSET));
        out.flush();
    }

}

方案二：使用spring mvc自带的jackson

1、web工程lib中加入jackson所需jar包：jackson-core-asl-1.9.9.jar、jackson-mapper-asl-1.9.9.jar

2、在applicationContext.xml中加入jackson的配置

<!-- json转换器 -->
<bean id="jsonConverter"
 class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">  <property name="supportedMediaTypes" value="application/json" />
</bean>

 

3、在你的action中直接使用注解的方式"@ResponseBody"自动将返回值转化成json格式

@Controller
@RequestMapping("task")
public class TaskControl { 
     @RequestMapping("getUserById") 
     @ResponseBody
     public List getUserById(Integer id) {
         return this.taskService.getUserById(id);
     } 
}

 

4、jsp页面的js写法跟普通ajax格式一样

functon getUserById(id){
    $.getJSON("task/getUserById",{id:id},function(data){
   
    });  
}

方案三：json-lib（待续）