/**
 * @author: PrincessHug
 * @date: 2019/3/25, 21:42
 * @Blog: https://www.cnblogs.com/HelloBigTable/
 */
public class OrderBean implements WritableComparable<OrderBean> {
    private int orderId;
    private double orderPrice;
 
    public OrderBean() {
    }
 
    public OrderBean(int orderId, double orderPrice) {
        this.orderId = orderId;
        this.orderPrice = orderPrice;
    }
 
    public int getOrderId() {
        return orderId;
    }
 
    public void setOrderId(int orderId) {
        this.orderId = orderId;
    }
 
    public double getOrderPrice() {
        return orderPrice;
    }
 
    public void setOrderPrice(double orderPrice) {
        this.orderPrice = orderPrice;
    }
 
    @Override
    public String toString() {
        return orderId + "\t" + orderPrice;
    }
 
    @Override
    public int compareTo(OrderBean o) {
        int rs ;
        if (this.orderId > o.getOrderId()){
            rs = 1;
        }else if (this.orderId < o.getOrderId()){
            rs = -1;
        }else {
            rs = (this.orderPrice > o.getOrderPrice()) ? -1:1;
        }
        return rs;
    }
 
    @Override
    public void write(DataOutput out) throws IOException {
        out.writeInt(orderId);
        out.writeDouble(orderPrice);
    }
 
    @Override
    public void readFields(DataInput in) throws IOException {
        orderId = in.readInt();
        orderPrice = in.readDouble();
    }
}
 
public class OrderMapper extends Mapper<LongWritable, Text,OrderBean, NullWritable> {
    @Override
    protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        //获取数据
        String line = value.toString();
 
        //切割数据
        String[] fields = line.split("\t");
 
        //封装数据
        int orderId = Integer.parseInt(fields[0]);
        double orderPrice = Double.parseDouble(fields[2]);
        OrderBean orderBean = new OrderBean(orderId, orderPrice);
 
        //发送数据
        context.write(orderBean,NullWritable.get());
    }
}
 
public class OrderPartitioner extends Partitioner<OrderBean, NullWritable> {
    @Override
    public int getPartition(OrderBean orderBean, NullWritable nullWritable, int i) {
        //构造参数中i的值为reducetask的个数
        return (orderBean.getOrderId() & Integer.MAX_VALUE ) % i;
    }
}
 
public class OrderReducer extends Reducer<OrderBean, NullWritable,OrderBean,NullWritable> {
    @Override
    protected void reduce(OrderBean key, Iterable<NullWritable> values, Context context) throws IOException, InterruptedException {
        context.write(key,NullWritable.get());
    }
}
 
public class OrderGrouptingComparator extends WritableComparator {
    //必须使用super调用父类的构造方法来定义对比的类为OrderBean
    protected OrderGrouptingComparator(){
        super(OrderBean.class,true);
    }
 
    @Override
    public int compare(WritableComparable a, WritableComparable b) {
        OrderBean aBean = (OrderBean)a;
        OrderBean bBean = (OrderBean)b;
 
        int rs ;
        if (aBean.getOrderId() > bBean.getOrderId()){
            rs = 1;
        }else if (aBean.getOrderId() < bBean.getOrderId()){
            rs = -1;
        }else {
            rs = 0;
        }
        return rs;
    }
}
 
public class OrderDriver {
    public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {
        //配置信息，Job对象
        Configuration conf = new Configuration();
        Job job = Job.getInstance(conf);
 
        //执行类
        job.setJarByClass(OrderBean.class);
 
        //设置Mapper、Reducer类
        job.setMapperClass(OrderMapper.class);
        job.setReducerClass(OrderReducer.class);
 
        //设置Mapper输出数据类型
        job.setMapOutputKeyClass(OrderBean.class);
        job.setMapOutputValueClass(NullWritable.class);
 
        //设置Reducer输出数据类型
        job.setOutputKeyClass(OrderBean.class);
        job.setOutputValueClass(NullWritable.class);
 
        //设置辅助排序
        job.setGroupingComparatorClass(OrderGrouptingComparator.class);
 
        //设置分区类
        job.setPartitionerClass(OrderPartitioner.class);
 
        //设置reducetask数量
        job.setNumReduceTasks(3);
 
        //设置文件输入输出流
        FileInputFormat.setInputPaths(job,new Path("G:\\mapreduce\\order\\in"));
        FileOutputFormat.setOutputPath(job,new Path("G:\\mapreduce\\order\\out"));
 
        //提交任务
        if (job.waitForCompletion(true)){
            System.out.println("运行完成！");
        }else {
            System.out.println("运行失败！");
        }
    }
}