Integration of TOS: Add common exceptions.

hadoop-cloud-storage-project/hadoop-tos/src/main/java/org/apache/hadoop/fs/tosfs/common/ChecksumMismatchException.java

@@ -0,0 +1,16 @@
+package org.apache.hadoop.fs.tosfs.common;
+
+import org.apache.hadoop.util.StringUtils;
+
+import java.io.IOException;
+
+public class ChecksumMismatchException extends IOException {
+  public ChecksumMismatchException(String message) {
+    super(message);
+  }
+
+  public ChecksumMismatchException(byte[] expected, byte[] actual) {
+    this(String.format("Expected checksum is %s while actual checksum is %s",
+        StringUtils.byteToHexString(expected), StringUtils.byteToHexString(actual)));
+  }
+}

hadoop-cloud-storage-project/hadoop-tos/src/main/java/org/apache/hadoop/fs/tosfs/common/InvalidObjectKeyException.java

@@ -0,0 +1,31 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.fs.tosfs.common;
+
+/**
+ * Regarding accessing an object in directory bucket, if the object is locating under an existing file in directory
+ * bucket, the {@link InvalidObjectKeyException} will be thrown. E.g. there is a file object 'a/b/file' exists in
+ * directory bucket, the {@link InvalidObjectKeyException} will be thrown if head object 'a/b/file/c' no matter
+ * whether 'c' exists or not.
+ */
+public class InvalidObjectKeyException extends RuntimeException {
+  public InvalidObjectKeyException(Throwable cause) {
+    super(cause);
+  }
+}

hadoop-cloud-storage-project/hadoop-tos/src/main/java/org/apache/hadoop/fs/tosfs/common/NotAppendableException.java

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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.fs.tosfs.common;
+
+public class NotAppendableException extends RuntimeException {
+  public NotAppendableException(String msg) {
+    super(msg);
+  }
+}