content: /*
   * 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 com.aliyun.odps.graph;
  
  import com.aliyun.odps.io.Writable;
  import com.aliyun.odps.io.WritableComparable;
  
  /**
   * Edge 表示图的一条边.
   *
   * <p>
   * 在 ODPS Graph 程序中，边总是依附于起点，所以 Edge 只存终点和边值。
   * </p>
   *
   * @param <VERTEX_ID>
   *     点类型
   * @param <EDGE_VALUE>
   *     边值类型
   */
  @SuppressWarnings("rawtypes")
  public final class Edge<VERTEX_ID extends WritableComparable, EDGE_VALUE extends Writable> {
  
    private VERTEX_ID destVertexId;
    private EDGE_VALUE value;
  
    /**
     * 给定终点和边值，构造一条边.
     *
     * @param destVertexId
     *     终点
     * @param value
     *     边值
     */
    public Edge(VERTEX_ID destVertexId, EDGE_VALUE value) {
      super();
      this.destVertexId = destVertexId;
      this.value = value;
    }
  
    /**
     * 返回边的终点.
     *
     * @return 边的终点
     */
    public VERTEX_ID getDestVertexId() {
      return destVertexId;
    }
  
    /**
     * 返回边的值
     *
     * @return 边值
     */
    public EDGE_VALUE getValue() {
      return value;
    }
  
    /**
     * 设置边值
     *
     * @param value
     *     边值
     */
    public void setValue(EDGE_VALUE value) {
      this.value = value;
    }
  
    /**
     * 边转换成字符串格式.
     * <p>
     * 字符串格式如下：
     * Edge[<目标顶点id>，<边的value>]
     * 注意：
     * 如果顶点id和边value是自定义类型，需要重写其toString()方法
     * </p>
     *
     * @return 边转换的字符串格式
     */
    @Override
    public String toString() {
      return "Edge [" + destVertexId + ", " + value + "]";
    }
  }
  