Java tutorial
/* * The MIT License (MIT) * * Copyright (c) 2013 Ian Hlavats. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. * */ package com.mycompany.model; import java.util.HashSet; import java.util.Set; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.ManyToOne; import javax.persistence.OneToMany; import org.apache.commons.lang.builder.EqualsBuilder; import org.apache.commons.lang.builder.HashCodeBuilder; /** * JPA entity for mind map data. This class is self-referencing and has a * hierarchical parent-child relationship so an idea can have any number of * sub-ideas. * * @author Ian Hlavats (ian@tarantulaconsulting.com) * */ @Entity public class Idea extends AbstractEntity { private static final String[] excludeFields = new String[] { "parent", "children" }; /** * */ private static final long serialVersionUID = -5778367117092282684L; private User author; private Set<Idea> children = new HashSet<Idea>(); private String description; private String name; private Idea parent; @Override public boolean equals(Object object) { return EqualsBuilder.reflectionEquals(this, object, excludeFields); } @ManyToOne public User getAuthor() { return author; } @OneToMany(mappedBy = "parent", fetch = FetchType.LAZY) public Set<Idea> getChildren() { return children; } public String getDescription() { return description; } public String getName() { return name; } @ManyToOne public Idea getParent() { return parent; } @Override public int hashCode() { return HashCodeBuilder.reflectionHashCode(this, excludeFields); } public void setAuthor(User author) { this.author = author; } public void setChildren(Set<Idea> children) { this.children = children; } public void setDescription(String description) { this.description = description; } public void setName(String name) { this.name = name; } public void setParent(Idea parent) { this.parent = parent; } }