字符串类型转json

 引入依赖

<dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.2.3</version>
            <classifier>jdk15</classifier>
        </dependency>

 JSONObject jsonObject = JSONObject.fromObject(new String(message.getPayload()));
 String DeviceNo = jsonObject.getString("DeviceNo");
 String MessageType = jsonObject.getString("MessageType");