java把map转json

JSONUtils.toJSONString(requestMap);    com.alibaba.fastjson.JSON

<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->  
<dependency>  
    <groupId>com.alibaba</groupId>  
    <artifactId>fastjson</artifactId>  
    <version>1.2.41</version>  
</dependency>