com.fasterxml.jackson.core.JsonParseException: Unrecognized token ‘Alarm‘: was expecting (JSON Stri

最近在使用httpclient进行post时远程接口发生报错

报错信息：

org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Unrecognized token 'Alarm': was expecting (JSON String, Number, Array, Object or token 'null', 'true' or 'false'); nested exception is com.fasterxml.jackson.core.JsonParseException: Unrecognized token 'Alarm': was expecting (JSON String, Number, Array, Object or token 'null', 'true' or 'false')

原因及解决方法：

原因是请求参数格式不正确，不是标准的json格式，通过JSONObject对象把参数转为json字符串即可，即修改消息体构造代码。

报错代码：

public HttpEntity httpPost(String url, Alarm data){
        try{
            CloseableHttpClient httpClient = HttpClients.createDefault();
            // 创建httpPost实例
            HttpPost post = new HttpPost(url);
            //构造消息头
            post.setHeader("Content-type", "application/json; charset=utf-8");
            // 构造消息体
            StringEntity entity = new StringEntity(data.toString(), ContentType.create("application/json", "utf-8"));
            post.setEntity(entity);
            CloseableHttpResponse response = httpClient.execute(post);
            HttpEntity responseEntity = response.getEntity();
            int statusCode = response.getStatusLine().getStatusCode();
            //最后关闭HttpClient资源.
            httpClient.close();
            return responseEntity;
        }catch (Exception e){
            e.printStackTrace();
            return null;
        }
    }

修改后的代码：

public HttpEntity httpPost(String url, Alarm data){
        try{
            CloseableHttpClient httpClient = HttpClients.createDefault();
            // 创建httpPost实例
            HttpPost post = new HttpPost(url);
            //构造消息头
            post.setHeader("Content-type", "application/json; charset=utf-8");
            // 构造消息体
            StringEntity entity = new StringEntity(new JSONObject(data).toString(), ContentType.create("application/json", "utf-8"));
            post.setEntity(entity);
            CloseableHttpResponse response = httpClient.execute(post);
            HttpEntity responseEntity = response.getEntity();
            int statusCode = response.getStatusLine().getStatusCode();
            //最后关闭HttpClient资源.
            httpClient.close();
            return responseEntity;
        }catch (Exception e){
            e.printStackTrace();
            return null;
        }
    }

JSONObject依赖：

        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20211205</version>
        </dependency>