首先,导入下面依赖
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.9</version>
</dependency>
接着使用ObjectMapper 将user对象转成json格式:
ObjectMapper objectMapper = new ObjectMapper();
String userJson = objectMapper.writeValueAsString(user);