1、org.apache.hadoop.fs.FileSystem

2、org.apache.hadoop.fs.Path

3、org.apache.hadoop.FileStatus

單元測試

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.Cluster;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;

public class FileStatusTest {
    private FileSystem fs;
    private Path path = new Path("hdfs://localhost/user/lhy/poem");
    private Cluster cluster;

    @Before
    public void setUp() throws IOException, InterruptedException {
        Configuration configuration = new Configuration();
        configuration.set("fs.defaultFS","hdfs://localhost");
        fs = FileSystem.get(configuration);
    }


    @After
    public void tearDown() throws IOException {
        if (fs != null){
            fs.close();
        }

        if (cluster != null){
            cluster.close();
        }
    }

    @Test
    public void pathTest() throws IOException {
        System.out.println("------------org.apache.hadoop.fs.Path-test-start----------");
        System.out.println("檔案或目錄的名字:"+ path.getName());
        System.out.println("檔案或目錄是否是絕對路徑:" + path.isAbsolute());
        System.out.println("是不是根目錄:" + path.isRoot());
        System.out.println("根目錄的深度是1，使用者目錄深度是2，此處檔案的深度是: " + path.depth());
        System.out.println("檔案或目錄的父資料夾:" + path.getParent());
        System.out.println("檔案或目錄isAbsoluteAndSchemeAuthorityNull:" + path.isAbsoluteAndSchemeAuthorityNull());
        System.out.println("檔案或目錄的父資料夾:" + path.getParent());
        System.out.println("檔案或目錄的URI Path 是不是絕對路徑:" + path.isUriPathAbsolute());
        System.out.println("為檔案或目錄新增字尾：" + path.suffix(".TXT"));
        System.out.println("path物件轉uri物件：" + path.toUri());
        System.out.println("------------org.apache.hadoop.fs.Path-test-end----------\n");
    }


    @Test
    public void fileStatusTest() throws IOException {
        System.out.println("------------org.apache.hadoop.fs.FileStatus-test-start----------");
        FileStatus fileStatus = fs.getFileStatus(path);
        System.out.println("檔案的path:" + fileStatus.getPath());
        System.out.println("檔案的上一次訪問時間:" + fileStatus.getAccessTime());
        System.out.println("檔案所屬組:" + fileStatus.getGroup());
        System.out.println("檔案的所屬:" + fileStatus.getOwner());
        System.out.println("檔案快的大小（單位bit）:" + fileStatus.getBlockSize());
        System.out.println("檔案內容長度" + fileStatus.getLen());
        System.out.println("檔案的許可權:"+ fileStatus.getPermission());
        System.out.println("最後修改時間:"+ fileStatus.getModificationTime());
//        System.out.println("檔案連線的路徑（軟連線或者硬連線的路徑）:"+ fileStatus.getSymlink());//if link path not found,will be throw an exception
        System.out.println("是否是一個資料夾:"+fileStatus.isDirectory());
        System.out.println("檔案是否設定ACL:"+fileStatus.hasAcl());
        System.out.println("檔案是否加密:"+fileStatus.isEncrypted());
        System.out.println("是否是檔案:"+fileStatus.isFile());
        System.out.println("檔案個副本個數:"+fileStatus.getReplication());
        System.out.println("是否使用快照:"+fileStatus.isSnapshotEnabled());
        System.out.println("------------org.apache.hadoop.fs.FileStatus-test-end----------\n");
    }

    @Test
    public void filSystemTest() throws IOException {
        Path path = new Path("poem");

        System.out.println("目錄或檔案是否存在：" + fs.exists(path));
        System.out.println("獲取檔案系統的服務地址：" + fs.getCanonicalServiceName());
//        Path newPath = new Path("test");
//        System.out.println("使用者目錄下建立資料夾test：" + fs.mkdirs(newPath));//如果已經存在，則會建立失敗，丟擲異常

//        System.out.println("本地檔案拷貝到hdfs，檔案存在則會覆蓋：");
//        Path localPath = new Path(URI.create("/Users/lhy/Desktop/春江花月夜.poem"));
//        fs.copyFromLocalFile(localPath,path);

        System.out.println("列出所有的檔案：");
        FileStatus[] fileStatuses = fs.listStatus(path);
        for (FileStatus fileStatus : fileStatuses){
            System.out.println(fileStatus.getPath());
        }

        System.out.println("列出所有過濾後的檔案：");
        FileStatus[] fileStatuses2 = fs.listStatus(path, path2 -> !path2.getName().contains("txt"));
        for (FileStatus fileStatus : fileStatuses2){
            System.out.println(fileStatus.getPath());
        }

    }

}