fix: set mediaType to null if contentType cannot be parsed (#911)

* fix: mediaType=null if contentType can't be parsed

Avoids users hitting a runtime exception when the contentType is
invalid.

* fix: add a contentType with params

google-http-client/src/main/java/com/google/api/client/http/HttpResponse.java

@@ -150,14 +150,30 @@ public final class HttpResponse {
       contentType = request.getResponseHeaders().getContentType();
     }
     this.contentType = contentType;
-    mediaType = contentType == null ? null : new HttpMediaType(contentType);
+    this.mediaType = parseMediaType(contentType);
 
     // log from buffer
     if (loggable) {
       logger.config(logbuf.toString());
     }
   }
 
+  /**
+   * Returns an {@link HttpMediaType} object parsed from {@link #contentType}, or {@code null} if
+   * if {@link #contentType} cannot be parsed or {@link #contentType} is {@code null}.
+   */
+  private static HttpMediaType parseMediaType(String contentType) {
+    if (contentType == null) {
+      return null;
+    }
+    try {
+      return new HttpMediaType(contentType);
+    } catch (IllegalArgumentException e) {
+      // contentType is invalid and cannot be parsed.
+      return null;
+    }
+  }
+
   /**
    * Returns the limit to the content size that will be logged during {@link #getContent()}.
    *

google-http-client/src/test/java/com/google/api/client/http/HttpResponseTest.java

@@ -58,6 +58,10 @@ public void testParseAsString_none() throws Exception {
 
   private static final String SAMPLE = "123\u05D9\u05e0\u05D9\u05D1";
   private static final String SAMPLE2 = "123abc";
+  private static final String VALID_CONTENT_TYPE = "text/plain";
+  private static final String VALID_CONTENT_TYPE_WITH_PARAMS =
+      "application/vnd.com.google.datastore.entity+json; charset=utf-8; version=v1; q=0.9";
+  private static final String INVALID_CONTENT_TYPE = "!!!invalid!!!";
 
   public void testParseAsString_utf8() throws Exception {
     HttpTransport transport =
@@ -102,6 +106,81 @@ public LowLevelHttpResponse execute() throws IOException {
     assertEquals(SAMPLE2, response.parseAsString());
   }
 
+  public void testParseAsString_validContentType() throws Exception {
+    HttpTransport transport =
+        new MockHttpTransport() {
+          @Override
+          public LowLevelHttpRequest buildRequest(String method, String url) throws IOException {
+            return new MockLowLevelHttpRequest() {
+              @Override
+              public LowLevelHttpResponse execute() throws IOException {
+                MockLowLevelHttpResponse result = new MockLowLevelHttpResponse();
+                result.setContent(SAMPLE2);
+                result.setContentType(VALID_CONTENT_TYPE);
+                return result;
+              }
+            };
+          }
+        };
+    HttpRequest request =
+        transport.createRequestFactory().buildGetRequest(HttpTesting.SIMPLE_GENERIC_URL);
+
+    HttpResponse response = request.execute();
+    assertEquals(SAMPLE2, response.parseAsString());
+    assertEquals(VALID_CONTENT_TYPE, response.getContentType());
+    assertNotNull(response.getMediaType());
+  }
+
+  public void testParseAsString_validContentTypeWithParams() throws Exception {
+    HttpTransport transport =
+        new MockHttpTransport() {
+          @Override
+          public LowLevelHttpRequest buildRequest(String method, String url) throws IOException {
+            return new MockLowLevelHttpRequest() {
+              @Override
+              public LowLevelHttpResponse execute() throws IOException {
+                MockLowLevelHttpResponse result = new MockLowLevelHttpResponse();
+                result.setContent(SAMPLE2);
+                result.setContentType(VALID_CONTENT_TYPE_WITH_PARAMS);
+                return result;
+              }
+            };
+          }
+        };
+    HttpRequest request =
+        transport.createRequestFactory().buildGetRequest(HttpTesting.SIMPLE_GENERIC_URL);
+
+    HttpResponse response = request.execute();
+    assertEquals(SAMPLE2, response.parseAsString());
+    assertEquals(VALID_CONTENT_TYPE_WITH_PARAMS, response.getContentType());
+    assertNotNull(response.getMediaType());
+  }
+
+  public void testParseAsString_invalidContentType() throws Exception {
+    HttpTransport transport =
+        new MockHttpTransport() {
+          @Override
+          public LowLevelHttpRequest buildRequest(String method, String url) throws IOException {
+            return new MockLowLevelHttpRequest() {
+              @Override
+              public LowLevelHttpResponse execute() throws IOException {
+                MockLowLevelHttpResponse result = new MockLowLevelHttpResponse();
+                result.setContent(SAMPLE2);
+                result.setContentType(INVALID_CONTENT_TYPE);
+                return result;
+              }
+            };
+          }
+        };
+    HttpRequest request =
+        transport.createRequestFactory().buildGetRequest(HttpTesting.SIMPLE_GENERIC_URL);
+
+    HttpResponse response = request.execute();
+    assertEquals(SAMPLE2, response.parseAsString());
+    assertEquals(INVALID_CONTENT_TYPE, response.getContentType());
+    assertNull(response.getMediaType());
+  }
+
   public void testStatusCode_negative_dontThrowException() throws Exception {
     subtestStatusCode_negative(false);
   }