Refactor service exceptions

gcloud-java-core/src/main/java/com/google/gcloud/BaseServiceException.java

@@ -16,26 +16,80 @@
 
 package com.google.gcloud;
 
+import com.google.api.client.googleapis.json.GoogleJsonError;
+import com.google.api.client.googleapis.json.GoogleJsonResponseException;
+
+import java.io.IOException;
+import java.net.SocketTimeoutException;
+import java.util.Collections;
+import java.util.Set;
+
 /**
  * Base class for all service exceptions.
  */
 public class BaseServiceException extends RuntimeException {
 
   private static final long serialVersionUID = 5028833760039966178L;
+  public static final int UNKNOWN_CODE = 0;
 
   private final int code;
   private final boolean retryable;
+  private final boolean idempotent;
+
+  public BaseServiceException(IOException exception, boolean idempotent) {
+    super(exception.getMessage(), exception);
+    this.code = statusCode(exception);
+    this.idempotent = idempotent;
+    this.retryable = idempotent && isRetryable(exception);
+  }
+
+  public BaseServiceException(GoogleJsonError error, boolean idempotent) {
+    super(error.getMessage());
+    this.code = error.getCode();
+    this.idempotent = idempotent;
+    this.retryable = idempotent && isRetryable(error);
+  }
 
-  public BaseServiceException(int code, String message, boolean retryable) {
+  public BaseServiceException(int code, String message, boolean retryable, boolean idempotent) {
     super(message);
     this.code = code;
-    this.retryable = retryable;
+    this.idempotent = idempotent;
+    this.retryable = idempotent && retryable;
   }
 
-  public BaseServiceException(int code, String message, boolean retryable, Exception cause) {
+  public BaseServiceException(int code, String message, boolean retryable, boolean idempotent,
+      Exception cause) {
     super(message, cause);
     this.code = code;
-    this.retryable = retryable;
+    this.idempotent = idempotent;
+    this.retryable = idempotent && retryable;
+  }
+
+  protected Set<Integer> retryableCodes() {
+    return Collections.emptySet();
+  }
+
+  protected int statusCode(IOException exception) {
+    if (exception instanceof GoogleJsonResponseException) {
+      if (((GoogleJsonResponseException) exception).getDetails() != null) {
+        return ((GoogleJsonResponseException) exception).getDetails().getCode();
+      }
+    }
+    return UNKNOWN_CODE;
+  }
+
+  protected boolean isRetryable(GoogleJsonError error) {
+    return error != null && retryableCodes().contains(error.getCode());
+  }
+
+  protected boolean isRetryable(IOException exception) {
+    if (exception instanceof GoogleJsonResponseException) {
+      return isRetryable(((GoogleJsonResponseException) exception).getDetails());
+    }
+    if (exception instanceof SocketTimeoutException) {
+      return true;
+    }
+    return false;
   }
 
   /**
@@ -51,4 +105,22 @@ public int code() {
   public boolean retryable() {
     return retryable;
   }
+
+  /**
+   * Returns {@code true} when the operation that caused this exception had no side effects.
+   */
+  public boolean idempotent() {
+    return idempotent;
+  }
+
+  protected static <T extends BaseServiceException> T translateAndThrow(
+      RetryHelper.RetryHelperException ex) {
+    if (ex.getCause() instanceof BaseServiceException) {
+      throw (T) ex.getCause();
+    }
+    if (ex instanceof RetryHelper.RetryInterruptedException) {
+      RetryHelper.RetryInterruptedException.propagate();
+    }
+    return null;
+  }
 }

gcloud-java-core/src/test/java/com/google/gcloud/BaseServiceExceptionTest.java

@@ -16,30 +16,91 @@
 
 package com.google.gcloud;
 
+import com.google.api.client.googleapis.json.GoogleJsonError;
+
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.replay;
+import static org.easymock.EasyMock.verify;
 import static org.junit.Assert.assertEquals;
 
 import org.junit.Test;
 
+import java.io.IOException;
+import java.net.SocketTimeoutException;
+
 /**
  * Tests for {@link BaseServiceException}.
  */
 public class BaseServiceExceptionTest {
 
-  private final int code = 1;
-  private final String message = "some message";
-  private final boolean retryable = true;
+  private static final int CODE = 1;
+  private static final String MESSAGE = "some message";
+  private static final boolean RETRYABLE = true;
+  private static final boolean IDEMPOTENT = true;
 
   @Test
   public void testBaseServiceException() {
-    BaseServiceException serviceException = new BaseServiceException(code, message, retryable);
-    assertEquals(serviceException.code(), code);
-    assertEquals(serviceException.getMessage(), message);
-    assertEquals(serviceException.getCause(), null);
+    BaseServiceException serviceException = new BaseServiceException(CODE, MESSAGE, RETRYABLE,
+        IDEMPOTENT);
+    assertEquals(CODE, serviceException.code());
+    assertEquals(MESSAGE, serviceException.getMessage());
+    assertEquals(RETRYABLE, serviceException.retryable());
+    assertEquals(IDEMPOTENT, serviceException.idempotent());
+    assertEquals(null, serviceException.getCause());
+
+    serviceException = new BaseServiceException(CODE, MESSAGE, RETRYABLE, false);
+    assertEquals(CODE, serviceException.code());
+    assertEquals(MESSAGE, serviceException.getMessage());
+    assertEquals(false, serviceException.retryable());
+    assertEquals(false, serviceException.idempotent());
+    assertEquals(null, serviceException.getCause());
 
     Exception cause = new RuntimeException();
-    serviceException = new BaseServiceException(code, message, retryable, cause);
-    assertEquals(serviceException.code(), code);
-    assertEquals(serviceException.getMessage(), message);
-    assertEquals(serviceException.getCause(), cause);
+    serviceException = new BaseServiceException(CODE, MESSAGE, RETRYABLE, IDEMPOTENT, cause);
+    assertEquals(CODE, serviceException.code());
+    assertEquals(MESSAGE, serviceException.getMessage());
+    assertEquals(RETRYABLE, serviceException.retryable());
+    assertEquals(IDEMPOTENT, serviceException.idempotent());
+    assertEquals(cause, serviceException.getCause());
+
+    serviceException = new BaseServiceException(CODE, MESSAGE, RETRYABLE, false, cause);
+    assertEquals(CODE, serviceException.code());
+    assertEquals(MESSAGE, serviceException.getMessage());
+    assertEquals(false, serviceException.retryable());
+    assertEquals(false, serviceException.idempotent());
+
+    IOException exception = new SocketTimeoutException();
+    serviceException = new BaseServiceException(exception, true);
+    assertEquals(true, serviceException.retryable());
+    assertEquals(true, serviceException.idempotent());
+    assertEquals(exception, serviceException.getCause());
+
+    GoogleJsonError error = new GoogleJsonError();
+    error.setCode(CODE);
+    error.setMessage(MESSAGE);
+    serviceException = new BaseServiceException(error, true);
+    assertEquals(CODE, serviceException.code());
+    assertEquals(MESSAGE, serviceException.getMessage());
+    assertEquals(false, serviceException.retryable());
+    assertEquals(true, serviceException.idempotent());
+  }
+
+  @Test
+  public void testTranslateAndThrow() throws Exception {
+    BaseServiceException cause = new BaseServiceException(CODE, MESSAGE, RETRYABLE, IDEMPOTENT);
+    RetryHelper.RetryHelperException exceptionMock = createMock(RetryHelper.RetryHelperException.class);
+    expect(exceptionMock.getCause()).andReturn(cause).times(2);
+    replay(exceptionMock);
+    try {
+      BaseServiceException.translateAndThrow(exceptionMock);
+    } catch (BaseServiceException ex) {
+      assertEquals(CODE, ex.code());
+      assertEquals(MESSAGE, ex.getMessage());
+      assertEquals(RETRYABLE, ex.retryable());
+      assertEquals(IDEMPOTENT, ex.idempotent());
+    } finally {
+      verify(exceptionMock);
+    }
   }
 }

gcloud-java-datastore/src/main/java/com/google/gcloud/datastore/BaseDatastoreBatchWriter.java

@@ -16,6 +16,9 @@
 
 package com.google.gcloud.datastore;
 
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkState;
+
 import com.google.api.services.datastore.DatastoreV1;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Iterables;
@@ -64,10 +67,8 @@ public final void addWithDeferredIdAllocation(FullEntity<?>... entities) {
 
   private void addInternal(FullEntity<Key> entity) {
     Key key = entity.key();
-    if (toAdd.containsKey(key) || toUpdate.containsKey(key) || toPut.containsKey(key)) {
-      throw newInvalidRequest("Entity with the key %s was already added or updated in this %s",
-          entity.key(), name);
-    }
+    checkArgument(!toAdd.containsKey(key) && !toUpdate.containsKey(key) && !toPut.containsKey(key),
+        "Entity with the key %s was already added or updated in this %s", entity.key(), name);
     if (toDelete.remove(key)) {
       toPut.put(key, entity);
     } else {
@@ -120,10 +121,8 @@ public final void update(Entity... entities) {
     validateActive();
     for (Entity entity : entities) {
       Key key = entity.key();
-      if (toDelete.contains(key)) {
-        throw newInvalidRequest("Entity with the key %s was already deleted in this %s",
-            entity.key(), name);
-      }
+      checkArgument(!toDelete.contains(key),
+          "Entity with the key %s was already deleted in this %s", entity.key(), name);
       if (toAdd.remove(key) != null || toPut.containsKey(key)) {
         toPut.put(key, entity);
       } else {
@@ -190,13 +189,7 @@ protected void deactivate() {
   }
 
   protected void validateActive() {
-    if (!active) {
-      throw newInvalidRequest("%s is no longer active", name);
-    }
-  }
-
-  protected DatastoreException newInvalidRequest(String msg, Object... params) {
-    return DatastoreException.throwInvalidRequest(String.format(msg, params));
+    checkState(active, "%s is no longer active", name);
   }
 
   protected DatastoreV1.Mutation.Builder toMutationPb() {

gcloud-java-datastore/src/main/java/com/google/gcloud/datastore/BaseEntity.java

@@ -16,6 +16,7 @@
 
 package com.google.gcloud.datastore;
 
+import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.gcloud.datastore.BlobValue.of;
 import static com.google.gcloud.datastore.BooleanValue.of;
 import static com.google.gcloud.datastore.DateTimeValue.of;
@@ -248,9 +249,7 @@ public boolean contains(String name) {
   public <V extends Value<?>> V getValue(String name) {
     @SuppressWarnings("unchecked")
     V property = (V) properties.get(name);
-    if (property == null) {
-      throw DatastoreException.throwInvalidRequest("No such property %s", name);
-    }
+    checkArgument(property != null, "No such property %s", name);
     return property;
   }