Draft support for WebTestClient (#514)

* Draft support for WebTestClient
* Share some common code between MockMvc and WebTestClient
* Fix co-ordinates of server stubs
* Fix project names in Gradle

samples/standalone/webclient/http-server/src/main/java/com/example/fraud/Application.java

@@ -0,0 +1,17 @@
+package com.example.fraud;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@EnableAutoConfiguration
+@ComponentScan
+public class Application {
+
+	public static void main(String[] args) {
+		SpringApplication.run(Application.class, args);
+	}
+
+}

samples/standalone/webclient/http-server/src/main/java/com/example/fraud/FraudDetectionController.java

@@ -0,0 +1,45 @@
+package com.example.fraud;
+
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.example.fraud.model.FraudCheck;
+import com.example.fraud.model.FraudCheckResult;
+import com.example.fraud.model.FraudCheckStatus;
+
+import java.math.BigDecimal;
+
+import static org.springframework.web.bind.annotation.RequestMethod.PUT;
+
+@RestController
+public class FraudDetectionController {
+
+	private static final String FRAUD_SERVICE_JSON_VERSION_1 = "application/vnd.fraud.v1+json";
+	private static final String NO_REASON = null;
+	private static final String AMOUNT_TOO_HIGH = "Amount too high";
+	private static final BigDecimal MAX_AMOUNT = new BigDecimal("5000");
+
+	// tag::server_api[]
+	@RequestMapping(
+			value = "/fraudcheck",
+			method = PUT,
+			consumes = FRAUD_SERVICE_JSON_VERSION_1,
+			produces = FRAUD_SERVICE_JSON_VERSION_1)
+	public FraudCheckResult fraudCheck(@RequestBody FraudCheck fraudCheck) {
+	// end::server_api[]
+		// tag::new_impl[]
+		if (amountGreaterThanThreshold(fraudCheck)) {
+			return new FraudCheckResult(FraudCheckStatus.FRAUD, AMOUNT_TOO_HIGH);
+		}
+		// end::new_impl[]
+		// tag::initial_impl[]
+		return new FraudCheckResult(FraudCheckStatus.OK, NO_REASON);
+		// end::initial_impl[]
+	}
+
+	private boolean amountGreaterThanThreshold(FraudCheck fraudCheck) {
+		return MAX_AMOUNT.compareTo(fraudCheck.getLoanAmount()) < 0;
+	}
+
+}

samples/standalone/webclient/http-server/src/main/java/com/example/fraud/model/FraudCheck.java

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+package com.example.fraud.model;
+
+import java.math.BigDecimal;
+
+public class FraudCheck {
+
+	private String clientId;
+
+	private BigDecimal loanAmount;
+
+	public FraudCheck() {
+	}
+
+	public String getClientId() {
+		return clientId;
+	}
+
+	public void setClientId(String clientId) {
+		this.clientId = clientId;
+	}
+
+	public BigDecimal getLoanAmount() {
+		return loanAmount;
+	}
+
+	public void setLoanAmount(BigDecimal loanAmount) {
+		this.loanAmount = loanAmount;
+	}
+}

samples/standalone/webclient/http-server/src/main/java/com/example/fraud/model/FraudCheckResult.java

@@ -0,0 +1,32 @@
+package com.example.fraud.model;
+
+public class FraudCheckResult {
+
+	private FraudCheckStatus fraudCheckStatus;
+
+	private String rejectionReason;
+
+	public FraudCheckResult() {
+	}
+
+	public FraudCheckResult(FraudCheckStatus fraudCheckStatus, String rejectionReason) {
+		this.fraudCheckStatus = fraudCheckStatus;
+		this.rejectionReason = rejectionReason;
+	}
+
+	public FraudCheckStatus getFraudCheckStatus() {
+		return fraudCheckStatus;
+	}
+
+	public void setFraudCheckStatus(FraudCheckStatus fraudCheckStatus) {
+		this.fraudCheckStatus = fraudCheckStatus;
+	}
+
+	public String getRejectionReason() {
+		return rejectionReason;
+	}
+
+	public void setRejectionReason(String rejectionReason) {
+		this.rejectionReason = rejectionReason;
+	}
+}

samples/standalone/webclient/http-server/src/main/java/com/example/fraud/model/FraudCheckStatus.java

@@ -0,0 +1,5 @@
+package com.example.fraud.model;
+
+public enum FraudCheckStatus {
+	OK, FRAUD
+}

samples/standalone/webclient/http-server/src/main/resources/application.yml

@@ -0,0 +1 @@
+server.port=0