add http headers to OAuth2ServiceException (#1256)

token-client/src/main/java/com/sap/cloud/security/xsuaa/client/DefaultOAuth2TokenService.java

@@ -27,6 +27,7 @@
 import java.io.UnsupportedEncodingException;
 import java.net.URI;
 import java.util.AbstractMap;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
@@ -108,6 +109,7 @@ private OAuth2TokenResponse executeRequest(HttpPost httpPost) throws OAuth2Servi
 				throw OAuth2ServiceException.builder("Error retrieving JWT token")
 						.withStatusCode(statusCode)
 						.withUri(httpPost.getURI())
+						.withHeaders(Arrays.toString(response.getAllHeaders()))
 						.withResponseBody(responseBodyAsString)
 						.build();
 			}

token-client/src/main/java/com/sap/cloud/security/xsuaa/client/OAuth2ServiceException.java

@@ -7,6 +7,9 @@
 
 import java.io.IOException;
 import java.net.URI;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 import java.util.Objects;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -18,6 +21,7 @@ public class OAuth2ServiceException extends IOException {
 
 	private static final long serialVersionUID = 1L;
 	private Integer httpStatusCode = 0;
+	private final List<String> headers = new ArrayList<>();
 
 	public OAuth2ServiceException(String message) {
 		super(message);
@@ -41,9 +45,15 @@ public OAuth2ServiceException(String message, Integer httpStatusCode) {
 	 *
 	 * @param message
 	 *            the error message
+	 * @param httpStatusCode
+	 *            the status code of the HTTP service request
+	 * @param headers
+	 * 	          the headers of the HTTP service request
 	 */
-	public static Builder builder(String message) {
-		return new Builder(message);
+
+	OAuth2ServiceException(String message, Integer httpStatusCode, List<String> headers) {
+		this(message, httpStatusCode);
+		this.headers.addAll(headers);
 	}
 
 	/**
@@ -56,20 +66,39 @@ public Integer getHttpStatusCode() {
 		return httpStatusCode;
 	}
 
+	/**
+	 * Returns the HTTP headers of the failed OAuth2 service request
+	 * @return list of HTTP headers
+	 */
+	public List<String> getHeaders() {
+		return this.headers;
+	}
+
+	/**
+	 * Creates an exception.
+	 *
+	 * @param message
+	 *            the error message
+	 */
+	public static Builder builder(String message) {
+		return new Builder(message);
+	}
+
 	public static class Builder {
-		private String message;
+		private final String message;
 		private Integer httpStatusCode;
 		private URI serverUri;
 		private String responseBody;
-		private String headers;
+		private final List<String> headers = new ArrayList<>();
+		private String headersString;
 
 		public Builder(String message) {
 			this.message = message;
 		}
 
 		/**
-		 * Parameterizes the Exception with a HTTP status code.
-		 * 
+		 * Parameterizes the Exception with an HTTP status code.
+		 *
 		 * @param httpStatusCode
 		 *            the http status code
 		 * @return the builder
@@ -90,21 +119,21 @@ public Builder withResponseBody(String responseBody) {
 		}
 
 		public Builder withHeaders(String... headers) {
-			this.headers = "[";
-			for (String header : headers) {
-				this.headers += header;
-			}
-			this.headers += "]";
+			List<String> headerList = Arrays.stream(headers).filter(Objects::nonNull).collect(Collectors.toList());
+
+			this.headers.addAll(headerList);
+			this.headersString = headerList.stream().collect(Collectors.joining(", ", "[", "]"));
+
 			return this;
 		}
 
 		public OAuth2ServiceException build() {
-			String message = Stream
+			String m = Stream
 					.of(this.message, createUriMessage(), createStatusCodeMessage(), createResponseBodyMessage(),
 							createHeaderMessage())
 					.filter(Objects::nonNull)
 					.collect(Collectors.joining(". "));
-			return new OAuth2ServiceException(message, httpStatusCode);
+			return new OAuth2ServiceException(m, httpStatusCode, headers);
 		}
 
 		private String createResponseBodyMessage() {
@@ -120,7 +149,7 @@ private String createUriMessage() {
 		}
 
 		private String createHeaderMessage() {
-			return headers == null ? null : "Headers " + headers;
+			return headersString == null ? null : "Headers " + headersString;
 		}
 
 	}

token-client/src/main/java/com/sap/cloud/security/xsuaa/client/XsuaaOAuth2TokenService.java

@@ -20,7 +20,10 @@
 
 import javax.annotation.Nonnull;
 import java.net.URI;
+import java.util.Collections;
+import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import static com.sap.cloud.security.xsuaa.Assertions.assertNotNull;
 import static com.sap.cloud.security.xsuaa.client.OAuth2TokenServiceConstants.*;
@@ -87,12 +90,12 @@ protected OAuth2TokenResponse requestAccessToken(URI tokenEndpointUri, HttpHeade
 			String warningMsg = String.format(
 					"Error retrieving JWT token. Received status code %s. Call to XSUAA was not successful: %s",
 					ex.getStatusCode(), ex.getResponseBodyAsString());
-			throw new OAuth2ServiceException(warningMsg);
+			throw new OAuth2ServiceException(warningMsg, ex.getStatusCode().value(), getHeaders(ex.getResponseHeaders()));
 		} catch (HttpServerErrorException ex) {
 			String warningMsg = String.format("Server error while obtaining access token from XSUAA (%s): %s",
 					ex.getStatusCode(), ex.getResponseBodyAsString());
 			LOGGER.error(warningMsg, ex);
-			throw new OAuth2ServiceException(warningMsg);
+			throw new OAuth2ServiceException(warningMsg, ex.getStatusCode().value(), getHeaders(ex.getResponseHeaders()));
 		} catch (ResourceAccessException ex) {
 			String warningMsg = String.format(
 					"RestClient isn't configured properly - Error while obtaining access token from XSUAA (%s): %s",
@@ -112,15 +115,22 @@ protected OAuth2TokenResponse requestAccessToken(URI tokenEndpointUri, HttpHeade
 		return new OAuth2TokenResponse(accessToken, expiresIn, refreshToken, tokenType);
 	}
 
+	private static List<String> getHeaders(org.springframework.http.HttpHeaders ex) {
+		if (ex != null){
+			return ex.toSingleValueMap().entrySet().stream().map(e -> e.getKey() + "=" + e.getValue()).collect(
+					Collectors.toList());
+		}
+		return Collections.emptyList();
+	}
+
 	/**
-	 * Creates a copy of the given map or an new empty map of type MultiValueMap.
+	 * Creates a copy of the given map or a new empty map of type MultiValueMap.
 	 *
 	 * @return a new @link{MultiValueMap} that contains all entries of the optional
 	 *         map.
 	 */
 	private MultiValueMap<String, String> copyIntoForm(Map<String, String> parameters) {
-		@SuppressWarnings("unchecked")
-		MultiValueMap<String, String> formData = new LinkedMultiValueMap();
+		MultiValueMap<String, String> formData = new LinkedMultiValueMap<>();
 		if (parameters != null) {
 			parameters.forEach(formData::add);
 		}

token-client/src/test/java/com/sap/cloud/security/xsuaa/client/OAuth2ServiceExceptionTest.java

@@ -0,0 +1,38 @@
+package com.sap.cloud.security.xsuaa.client;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class OAuth2ServiceExceptionTest {
+    public static final String SERVICE_EXCEPTION = "Service Exception";
+    private static List<String> headers;
+    private static OAuth2ServiceException builtWithHeaders;
+    private static OAuth2ServiceException createdWithHeaders;
+
+    @BeforeAll
+    static void setup() {
+        headers = new ArrayList<>();
+        headers.add("header1=value1");
+        headers.add("header2=value2");
+        builtWithHeaders = OAuth2ServiceException.builder(SERVICE_EXCEPTION).withHeaders(headers.toArray(new String[0])).withStatusCode(400).build();
+        createdWithHeaders = new OAuth2ServiceException(SERVICE_EXCEPTION, 400, headers);
+    }
+
+    @Test
+    void testWithHeaders() {
+        assertIterableEquals(headers, builtWithHeaders.getHeaders());
+        assertTrue(builtWithHeaders.getMessage().contains(SERVICE_EXCEPTION));
+        assertTrue(builtWithHeaders.getMessage().contains("[header1=value1, header2=value2]"));
+        assertEquals(400, builtWithHeaders.getHttpStatusCode());
+
+        assertIterableEquals(headers, createdWithHeaders.getHeaders());
+        assertTrue(createdWithHeaders.getMessage().contains(SERVICE_EXCEPTION));
+        assertFalse(createdWithHeaders.getMessage().contains("[header1=value1, header2=value2]"));
+        assertEquals(400, createdWithHeaders.getHttpStatusCode());
+    }
+}