通过java api统计hive库下的所有表的文件个数、文件大小

更新hadoop fs 命令实现：

[ss@db csv]$ hadoop fs -count /my_rc/my_hive_db/*
18/01/14 15:40:19 INFO hdfs.PeerCache: SocketCache disabled.
           3            2                  0 /my_rc/my_hive_db/.hive-staging_hive_2017-08-19_16-52-39_153_7217997288202811839-170149
           2            0                  0 /my_rc/my_hive_db/.hive-staging_hive_2018-01-03_15-23-10_240_5147839610865108930-52517
           1            0                  0 /my_rc/my_hive_db/BusinessGtUser
           4            1             321008 /my_rc/my_hive_db/ZJ2_SenseSta
           1            1                143 /my_rc/my_hive_db/anthgain
           1            1              27228 /my_rc/my_hive_db/anthgainpoint
           1            1                 70 /my_rc/my_hive_db/antvgain
           1            1              27429 /my_rc/my_hive_db/antvgainpoint

通过hadoop fs -du 或者 hadoop fs -count只能统计指定的某个hdfs路径(hive表目录)的总文件个数及文件的大小，但是通过hadoop命令没有办法实现批量处理hive中多个表一次进行统计，如果一次性统计多个hive表目录的文件个数、文件总大小只能通过java程序使用hadoop api实现。

package com.my.hdfsopt;

import java.io.FileNotFoundException;
import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;

public class HdfsPathMonitor {
    // submit shell
    /*
     * main类的路径不需要指定，否则会被认为是参数传递进入。
     * yarn jar /app/m_user1/service/Hangzhou_HdfsFileMananger.jar /hive_tenant_account/hivedbname/
     */
    public static void main(String[] args) throws Exception {
        System.out.println("the args is " + String.join(",", args));
        String dirPath = args[0];

        Configuration conf = new Configuration();
        /*
         * <property> <name>fs.defaultFS</name> <value>hdfs://mycluster</value>
         * </property>
         */
        conf.set("fs.defaultFS", "hdfs://mycluster");

        FileSystem fileSystem = FileSystem.get(conf);
        Path path = new Path(dirPath);

        // 获取文件列表
        FileStatus[] files = fileSystem.listStatus(path);
        if (files == null || files.length == 0) {
            throw new FileNotFoundException("Cannot access " + dirPath + ": No such file or directory.");
        }

        System.out.println("dirpath \t total file size \t total file count");
        for (int i = 0; i < files.length; i++) {
            String pathStr = files[i].getPath().toString();

            FileSystem fs = files[i].getPath().getFileSystem(conf);
            long totalSize = fs.getContentSummary(files[i].getPath()).getLength();
            long totalFileCount = listAll(conf, files[i].getPath());
            fs.close();

            System.out.println(("".equals(pathStr) ? "." : pathStr) + "\t" + totalSize + "\t" + totalFileCount);
        }
    }

    /**
     * @Title: listAll @Description: 列出目录下所有文件 @return void 返回类型 @throws
     */
    public static Long listAll(Configuration conf, Path path) throws IOException {
        long totalFileCount = 0;
        FileSystem fs = FileSystem.get(conf);

        if (fs.exists(path)) {
            FileStatus[] stats = fs.listStatus(path);
            for (int i = 0; i < stats.length; ++i) {
                if (!stats[i].isDir()) {
                    // regular file
                    // System.out.println(stats[i].getPath().toString());
                    totalFileCount++;
                } else {
                    // dir
                    // System.out.println(stats[i].getPath().toString());
                    totalFileCount += listAll(conf, stats[i].getPath());
                }
            }
        }
        fs.close();

        return totalFileCount;
    }

}

执行命令：

yarn jar /app/m_user1/tommyduan_service/Hangzhou_HdfsFileMananger.jar /hive_tenant_account/hivedbname/

执行结果：