图计算秒杀

import org.apache.giraph.graph.BasicComputation;
import org.apache.giraph.graph.Vertex;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;

public class UserBehaviorComputation extends BasicComputation<LongWritable, Text, IntWritable, Text> {

    @Override
    public void compute(Vertex<LongWritable, Text, IntWritable> vertex, Iterable<Text> messages) {
        // 处理接收到的消息
        for (Text message : messages) {
            // 更新节点状态
            vertex.setValue(new Text(message.toString() + "_processed"));
        }
        // 发送消息给相邻节点
        for (Edge<LongWritable, IntWritable> edge : vertex.getEdges()) {
            sendMessage(edge.getTargetVertexId(), new Text(vertex.getValue().toString()));
        }
    }

    @Override
    public void preSuperstep() {
        // 初始化节点状态
        for (Vertex<LongWritable, Text, IntWritable> vertex : getGraph().getVertices()) {
            vertex.setValue(new Text("initial_state"));
        }
    }
}