Java tutorial
/* * 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.hise.dao; import java.util.ArrayList; import java.util.Collections; import java.util.List; import javax.persistence.MappedSuperclass; import org.apache.commons.lang.builder.HashCodeBuilder; import org.apache.commons.lang.builder.ToStringBuilder; @MappedSuperclass public abstract class JpaBase { public abstract Object[] getKeys(); @Override public int hashCode() { HashCodeBuilder b = new HashCodeBuilder(); for (Object o : getKeys()) { b.append(o); } return b.toHashCode(); } @Override public boolean equals(Object obj) { if (obj == null) return false; List<Object> l1 = new ArrayList<Object>(); Collections.addAll(l1, getKeys()); List<Object> l2 = new ArrayList<Object>(); Collections.addAll(l2, ((JpaBase) obj).getKeys()); return l1.equals(l2); } @Override public String toString() { ToStringBuilder b = new ToStringBuilder(this); for (Object o : getKeys()) { b.append(o); } return b.toString(); } }