BAEL-9458: Sending XML POST Requests with Spring RestTemplate

spring-web-modules/spring-resttemplate-3/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>spring-resttemplate-3</artifactId>
     <version>0.1-SNAPSHOT</version>
@@ -63,6 +63,12 @@
             <artifactId>commons-io</artifactId>
             <version>${commons-io.version}</version>
         </dependency>
+
+        <!-- XML support using Jackson -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-xml</artifactId>
+        </dependency>
     </dependencies>
 
     <properties>

spring-web-modules/spring-resttemplate-3/src/main/java/com/baeldung/xmlpost/config/RestTemplateConfig.java

@@ -0,0 +1,13 @@
+package com.baeldung.xmlpost.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.client.RestTemplate;
+
+@Configuration
+public class RestTemplateConfig {
+    @Bean
+    public RestTemplate restTemplate() {
+        return new RestTemplate();
+    }
+}

spring-web-modules/spring-resttemplate-3/src/main/java/com/baeldung/xmlpost/model/PaymentRequest.java

@@ -0,0 +1,62 @@
+package com.baeldung.xmlpost.model;
+
+import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
+import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
+
+@JacksonXmlRootElement(localName = "PaymentRequest")
+public class PaymentRequest {
+
+    @JacksonXmlProperty(localName = "transactionId")
+    private String transactionId;
+
+    @JacksonXmlProperty(localName = "amount")
+    private Double amount;
+
+    @JacksonXmlProperty(localName = "currency")
+    private String currency;
+
+    @JacksonXmlProperty(localName = "recipient")
+    private String recipient;
+
+    public PaymentRequest() {
+    }
+
+    public PaymentRequest(String transactionId, Double amount, String currency, String recipient) {
+        this.transactionId = transactionId;
+        this.amount = amount;
+        this.currency = currency;
+        this.recipient = recipient;
+    }
+
+    public String getTransactionId() {
+        return transactionId;
+    }
+
+    public void setTransactionId(String transactionId) {
+        this.transactionId = transactionId;
+    }
+
+    public Double getAmount() {
+        return amount;
+    }
+
+    public void setAmount(Double amount) {
+        this.amount = amount;
+    }
+
+    public String getCurrency() {
+        return currency;
+    }
+
+    public void setCurrency(String currency) {
+        this.currency = currency;
+    }
+
+    public String getRecipient() {
+        return recipient;
+    }
+
+    public void setRecipient(String recipient) {
+        this.recipient = recipient;
+    }
+}

spring-web-modules/spring-resttemplate-3/src/main/java/com/baeldung/xmlpost/model/PaymentResponse.java

@@ -0,0 +1,50 @@
+package com.baeldung.xmlpost.model;
+
+import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
+import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
+
+@JacksonXmlRootElement(localName = "PaymentResponse")
+public class PaymentResponse {
+
+    @JacksonXmlProperty(localName = "status")
+    private String status;
+
+    @JacksonXmlProperty(localName = "message")
+    private String message;
+
+    @JacksonXmlProperty(localName = "referenceNumber")
+    private String referenceNumber;
+
+    public PaymentResponse() {
+    }
+
+    public PaymentResponse(String status, String message, String referenceNumber) {
+        this.status = status;
+        this.message = message;
+        this.referenceNumber = referenceNumber;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+
+    public void setStatus(String status) {
+        this.status = status;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+
+    public String getReferenceNumber() {
+        return referenceNumber;
+    }
+
+    public void setReferenceNumber(String referenceNumber) {
+        this.referenceNumber = referenceNumber;
+    }
+}

spring-web-modules/spring-resttemplate-3/src/main/java/com/baeldung/xmlpost/service/PaymentService.java

@@ -0,0 +1,39 @@
+package com.baeldung.xmlpost.service;
+
+import com.baeldung.xmlpost.model.PaymentRequest;
+import com.baeldung.xmlpost.model.PaymentResponse;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.RestTemplate;
+
+import java.util.Collections;
+
+@Service
+public class PaymentService {
+    private final RestTemplate restTemplate;
+
+    public PaymentService(RestTemplate restTemplate) {
+        this.restTemplate = restTemplate;
+    }
+
+    public PaymentResponse processPayment(PaymentRequest request, String paymentUrl) {
+        try {
+            HttpHeaders headers = new HttpHeaders();
+            headers.setContentType(MediaType.APPLICATION_XML);
+            headers.setAccept(Collections.singletonList(MediaType.APPLICATION_XML));
+
+            HttpEntity<PaymentRequest> entity = new HttpEntity<>(request, headers);
+
+            ResponseEntity<PaymentResponse> response =
+              restTemplate.postForEntity(paymentUrl, entity, PaymentResponse.class);
+
+            return response.getBody();
+        } catch (Exception ex) {
+            throw new RuntimeException("Payment processing failed: " + ex.getMessage(), ex);
+        }
+    }
+}
+

spring-web-modules/spring-resttemplate-3/src/test/java/com/baeldung/xmlpost/service/PaymentServiceUnitTest.java

@@ -0,0 +1,92 @@
+package com.baeldung.xmlpost.service;
+
+import com.baeldung.xmlpost.model.PaymentRequest;
+import com.baeldung.xmlpost.model.PaymentResponse;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.client.HttpClientErrorException;
+import org.springframework.web.client.RestTemplate;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.*;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class PaymentServiceUnitTest {
+
+    @Mock
+    private RestTemplate restTemplate;
+
+    @InjectMocks
+    private PaymentService paymentService;
+
+    private final String testUrl = "http://mock-payment-service";
+
+    @Test
+    void givenValidPaymentRequest_whenProcessPayment_thenReturnSuccessfulResponse() {
+        PaymentRequest request = new PaymentRequest("TXN001", 100.50, "USD", "Jane Doe");
+        PaymentResponse expectedResponse = new PaymentResponse(
+          "SUCCESS", "Payment processed successfully", "REF12345"
+        );
+
+        ResponseEntity<PaymentResponse> mockResponse =
+          new ResponseEntity<>(expectedResponse, HttpStatus.OK);
+
+        when(restTemplate.postForEntity(eq(testUrl), any(HttpEntity.class), eq(PaymentResponse.class)))
+          .thenReturn(mockResponse);
+
+        PaymentResponse actualResponse = paymentService.processPayment(request, testUrl);
+
+        assertNotNull(actualResponse);
+        assertEquals("SUCCESS", actualResponse.getStatus());
+        assertEquals("REF12345", actualResponse.getReferenceNumber());
+        assertEquals("Payment processed successfully", actualResponse.getMessage());
+
+        verify(restTemplate).postForEntity(eq(testUrl), any(HttpEntity.class), eq(PaymentResponse.class));
+    }
+
+    @Test
+    void givenRemoteServiceReturnsBadRequest_whenProcessPayment_thenThrowMeaningfulException() {
+        PaymentRequest request = new PaymentRequest("TXN002", 200.0, "EUR", "John Smith");
+
+        when(restTemplate.postForEntity(eq(testUrl), any(HttpEntity.class), eq(PaymentResponse.class)))
+          .thenThrow(new HttpClientErrorException(HttpStatus.BAD_REQUEST, "Invalid amount"));
+
+        RuntimeException exception = assertThrows(RuntimeException.class,
+          () -> paymentService.processPayment(request, testUrl));
+
+        assertTrue(exception.getMessage().contains("Payment processing failed"));
+        assertTrue(exception.getMessage().contains("Invalid amount"));
+    }
+
+    @Test
+    void givenXmlRequest_whenProcessPayment_thenSetCorrectXmlHttpHeaders() {
+        PaymentRequest request = new PaymentRequest("TXN004", 300.0, "CAD", "Bob Wilson");
+        PaymentResponse expectedResponse = new PaymentResponse("SUCCESS", "OK", "REF67890");
+
+        when(restTemplate.postForEntity(eq(testUrl), any(HttpEntity.class), eq(PaymentResponse.class)))
+          .thenReturn(new ResponseEntity<>(expectedResponse, HttpStatus.OK));
+
+        paymentService.processPayment(request, testUrl);
+
+        verify(restTemplate).postForEntity(
+          eq(testUrl),
+          argThat((HttpEntity<PaymentRequest> entity) -> {
+              boolean hasXmlContentType = entity.getHeaders().getContentType()
+                .includes(MediaType.APPLICATION_XML);
+              boolean acceptsXml = entity.getHeaders().getAccept()
+                .contains(MediaType.APPLICATION_XML);
+              return hasXmlContentType && acceptsXml;
+          }),
+          eq(PaymentResponse.class)
+        );
+    }
+}