LMS-94 Add method register-master-plate

SVN: 1590

common/source/java/ch/systemsx/cisd/common/exceptions/InternalErr.java

+/*
+ * Copyright 2007 ETH Zuerich, CISD
+ *
+ * Licensed 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 ch.systemsx.cisd.common.exceptions;
+
+/**
+ * Exception representing internal error in the program caused by programmer error. It should never be caught. <br>
+ * <br>
+ * This class becomes handy when we do comparition of some value with the enumerator. The following 'enum-match' pattern
+ * should be applied: 1. all values of the enumerator should be checked 2. if no matching of the value and enumerator is
+ * found, it is a programmer mistake and internal error occurs. It means that when one adds a new enumerator value, one
+ * should check every comparition of other values and update them.
+ * 
+ * <pre>
+ * Example:
+ * enum TypeX { A, B, C }
+ *  
+ * void doSomething(TypeX value) {
+ *   if (value.equals(TypeX.A) {
+ *      // process A
+ *   } else if (value.equals(TypeX.B) {
+ *      // process C
+ *   } else if (value.equals(TypeX.C) {
+ *      // process C
+ *   } else
+ *     throw InternalErr.error();
+ * }
+ * </pre>
+ * 
+ * @author Tomasz Pylak on Sep 3, 2007
+ */
+public class InternalErr extends RuntimeException
+{
+    private static final InternalErr instance = new InternalErr();
+
+    private static final long serialVersionUID = 1L;
+
+    private InternalErr()
+    {
+    }
+
+    public static final RuntimeException error()
+    {
+        assert false : "This should never happen";
+        return instance;
+    }
+}