svn commit: r1028051 - in /incubator/thrift/trunk/lib/java: src/org/apache/thrift/TEnumHelper.java test/org/apache/thrift/TestTEnumHelper.java

[br...@apache.org]

Author: bryanduxbury
Date: Wed Oct 27 17:54:10 2010
New Revision: 1028051

URL: http://svn.apache.org/viewvc?rev=1028051&view=rev
Log:
THRIFT-949. java: Modify the TEnum interface so it defines a method similar to findByValue

This patch adds a new helper class that makes it easier to get instances of generic TEnum descendents by value.

Patch: Mathias Herberts

Added:
    incubator/thrift/trunk/lib/java/src/org/apache/thrift/TEnumHelper.java
    incubator/thrift/trunk/lib/java/test/org/apache/thrift/TestTEnumHelper.java

Added: incubator/thrift/trunk/lib/java/src/org/apache/thrift/TEnumHelper.java
URL: http://svn.apache.org/viewvc/incubator/thrift/trunk/lib/java/src/org/apache/thrift/TEnumHelper.java?rev=1028051&view=auto
==============================================================================
--- incubator/thrift/trunk/lib/java/src/org/apache/thrift/TEnumHelper.java (added)
+++ incubator/thrift/trunk/lib/java/src/org/apache/thrift/TEnumHelper.java Wed Oct 27 17:54:10 2010
@@ -0,0 +1,57 @@
+/*
+ * 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.thrift;
+
+import java.lang.InstantiationException;
+import java.lang.NoSuchMethodException;
+import java.lang.IllegalAccessException;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+/**
+ * Utility class with static methods for interacting with TEnum
+ */
+public class TEnumHelper {
+
+  /**
+   * Given a TEnum class and integer value, this method will return
+   * the associated constant from the given TEnum class.
+   * This method MUST be modified should the name of the 'findByValue' method
+   * change.
+   *
+   * @param enumClass TEnum from which to return a matching constant.
+   * @param value Value for which to return the constant.
+   *
+   * @return The constant in 'enumClass' whose value is 'value' or null if
+   *         something went wrong.
+   */
+  public static TEnum getByValue(Class<? extends TEnum> enumClass, int value) {
+    try {
+      Method method = enumClass.getMethod("findByValue", int.class);
+      return (TEnum) method.invoke(null, value);
+    } catch (NoSuchMethodException nsme) {
+      return null;
+    } catch (IllegalAccessException iae) {
+      return null;
+    } catch (InvocationTargetException ite) {
+      return null;
+    }
+  }
+}

Added: incubator/thrift/trunk/lib/java/test/org/apache/thrift/TestTEnumHelper.java
URL: http://svn.apache.org/viewvc/incubator/thrift/trunk/lib/java/test/org/apache/thrift/TestTEnumHelper.java?rev=1028051&view=auto
==============================================================================
--- incubator/thrift/trunk/lib/java/test/org/apache/thrift/TestTEnumHelper.java (added)
+++ incubator/thrift/trunk/lib/java/test/org/apache/thrift/TestTEnumHelper.java Wed Oct 27 17:54:10 2010
@@ -0,0 +1,41 @@
+/*
+ * 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.thrift;
+
+import thrift.test.Numberz;
+
+import junit.framework.TestCase;
+
+public class TestTEnumHelper extends TestCase {
+
+  public void testGetByValue_ValidValues() {
+    for (Numberz n: Numberz.values()) {
+      int value = n.getValue();
+      assertEquals(n, TEnumHelper.getByValue(Numberz.class, value));
+    } 
+  }
+
+  public void testGetByValue_InvalidValue() {
+    assertEquals(null, TEnumHelper.getByValue(Numberz.class, 0));
+  }
+
+  public void testGetByValue_InvalidClass() {
+    assertEquals(null, TEnumHelper.getByValue(TEnum.class, 0));
+  }
+}