1.导入maven,有时自带jar，导入之后有冲突说明已有jar包，删掉maven中的pomjar包

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.11.2</version>
</dependency>

2.new ObjectMapper()使用

@Override
    public void  addTank(JSONObject tank) throws IOException {
        ObjectMapper mapper = new ObjectMapper();
        mapper.readValue(tank.toJSONString(),TTankEntity.class);
        System.out.println(tank.toString());
    }

若返回的JSON字符串中只有该实体类中的部分属性会报not marked as ignorable (56 known properties: 的错误，这时需要在实体类的类上方加上@JsonIgnoreProperties(ignoreUnknown = true)的注解

@JsonIgnoreProperties(ignoreUnknown = true)