package com.example.restclient; import org.springframework.http.HttpEntity; import org.springframework.http.HttpHeaders; import org.springframework.http.HttpMethod; import org.springframework.http.MediaType; import org.springframework.http.ResponseEntity; import org.springframework.stereotype.Component; import org.springframework.web.client.RestTemplate; @Component public class RestHandler { private final RestTemplate restTemplate; public RestHandler(RestTemplate restTemplate) { this.restTemplate = restTemplate; } public String callMainframeService(String requestPayload) { String mainframeServiceUrl = "http://your-mainframe-host:port/submit/sync"; // Replace with actual URL HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_XML); // Assuming XML payload, adjust if needed HttpEntity requestEntity = new HttpEntity<>(requestPayload, headers); try { ResponseEntity responseEntity = restTemplate.exchange( mainframeServiceUrl, HttpMethod.POST, requestEntity, String.class); if (responseEntity.getStatusCode().is2xxSuccessful()) { return responseEntity.getBody(); } else { // Handle non-2xx status codes as needed return "Error: Mainframe service returned status code: " + responseEntity.getStatusCode(); } } catch (Exception e) { // Handle exceptions (e.g., connection errors, timeouts) return "Error calling mainframe service: " + e.getMessage(); } } } package com.example.restclient; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.Bean; import org.springframework.web.client.RestTemplate; @SpringBootApplication public class RestClientApplication { public static void main(String[] args) { SpringApplication.run(RestClientApplication.class, args); } @Bean public RestTemplate restTemplate() { return new RestTemplate(); } } ``` 4.0.0 com.example rest-client 0.0.1-SNAPSHOT rest-client rest-client 17

3.2.3

org.springframework.boot spring-boot-starter-web ${spring-boot.version} org.springframework.boot spring-boot-starter-test ${spring-boot.version} test org.springframework.boot spring-boot-maven-plugin ${spring-boot.version} org.springframework.boot spring-boot-dependencies ${spring-boot.version} pom import ``` package com.example.restclient; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RestController; @RestController public class MainController { private final RestHandler restHandler; public MainController(RestHandler restHandler) { this.restHandler = restHandler; } @PostMapping("/call-mainframe") public String callMainframe(@RequestBody String requestPayload) { return restHandler.callMainframeService(requestPayload); } } ``` ```