I am working on spring boot application for consuming external API using RestTemplate.

Below is the service class that I have written to get response from external API:

public String getReportListByClientId(String clientId) {
        ResponseEntity<String> responseEntity = null;
        String jsonResponse = null;
        try {
            final String uri = "https://chapi.cloudhealthtech.com/olap_reports/custom?client_api_id=" clientId;
            RestTemplate restTemplate = new RestTemplate();
            HttpHeaders header = new HttpHeaders();
            header.set(HttpHeaders.AUTHORIZATION, "Bearer " apiKey);
            header.set(HttpHeaders.ACCEPT, "application/json");
            
            HttpEntity<String> requestEntity = new HttpEntity<String>("body",header);
            responseEntity = restTemplate.exchange(uri, HttpMethod.GET, requestEntity, String.class);
            
            jsonResponse =  responseEntity.getBody();   
        } catch (Exception e) {
            e.printStackTrace();
        }
    return jsonResponse;
}

The following is the response that I am getting using exchange() method:

{
    "links": {
        "RCDSO - Production Environment Cost": {
            "href": "href 1"
        },
        "RCDSO - Development & UAT Environment Cost": {
            "href": "href 2"
        },
        "RCDSO - Total Cost for Prod - Compugen Managed": {
            "href": "href 3"
        },
        "RCDSO - Virtual Machine Cost": {
            "href": "href 4"
        },
        "RCDSO - Azure File Storage Cost": {
            "href": "href 5"
        },
        "RCDSO - Azure Backup and Site Recovery": {
            "href": "href 6"
        },
        "RCDSO - Azure App Services Cost": {
            "href": "href 7"
        }
    }
}

So now, before sending response to client side in my application. I want to fetch data from this response and want to do some manipulation and convert that into custom POJO class. I tried using JSONObject but got some exceptions.

I want to display this JSON data in HTML table using AJAX.

So how should I extract or get individual data from above JSON?

CodePudding user response：

Based on the JSON structure, let's assume you have the following POJOs:

public class Report implements Serializable {
    private Map<String, Link> links;
    // getters, setters
}

public class Link {
    private String href;
    // getters, setters
}

Now instead of extracting the response body as a JSON String, convert it to POJO directly.

public Report getReportListByClientId(String clientId) {
        
        ResponseEntity<Report> responseEntity = null;
        
        try {
            ..
            responseEntity = restTemplate.exchange(uri, HttpMethod.GET, requestEntity, Report.class);
            
            return responseEntity.getBody();

        } catch (Exception e) {
           ..
        }
}

Assumption: the project has Jackson in classpath, so MappingJacksonHttpMessageConverter will be enabled by default with RestTemplate for the above method to work.

CodePudding user response：

I will try to help u. You can use JsonPath to manipulate your string json.

    <dependency>
        <groupId>com.jayway.jsonpath</groupId>
        <artifactId>json-path</artifactId>
        <version>2.7.0</version>
    </dependency>

add this library to your code and then try to use this

        String json = """
            {
                "links": {
                    "RCDSO - Production Environment Cost": {
                        "href": "href 1"
                    },
                    "RCDSO - Development & UAT Environment Cost": {
                        "href": "href 2"
                    },
                    "RCDSO - Total Cost for Prod - Compugen Managed": {
                        "href": "href 3"
                    },
                    "RCDSO - Virtual Machine Cost": {
                        "href": "href 4"
                    },
                    "RCDSO - Azure File Storage Cost": {
                        "href": "href 5"
                    },
                    "RCDSO - Azure Backup and Site Recovery": {
                        "href": "href 6"
                    },
                    "RCDSO - Azure App Services Cost": {
                        "href": "href 7"
                    }
                }
            }
            """;
    Map<String, Map<String, String>> links = JsonPath.read(json, "$.links");
    links.forEach((key, value) -> {
        System.out.println("k = "   key);
        System.out.print("v = ");
        value.forEach((key2, value2) -> {
            System.out.println("key = "   key2   " : value = "   value2);
        });
    });