Example usage for java.io FileSystem delete

Introduction

In this page you can find the example usage for java.io FileSystem delete.

Prototype

public abstract boolean delete(File f);

Source Link

Document

Delete the file or directory denoted by the given abstract pathname, returning true if and only if the operation succeeds.

Usage

From source file:org.apache.hadoop.hdfs.server.namenode.TestWaitingRoomPurger.java

public void testWaitingRoomPurger() throws IOException {
    Configuration conf = new Configuration();
    MiniDFSCluster cluster = new MiniDFSCluster(conf, 1, true, null);
    cluster.waitClusterUp();/*w  ww. ja  v  a2s  .  c o  m*/
    FileSystem fs = cluster.getFileSystem();

    WaitingRoom wr = new WaitingRoom(conf);
    WaitingRoomPurger purger = wr.getPurger();
    SnapshotNode ssNode = new SnapshotNode(conf);
    ssNode.shutdownWaitingRoomPurger();

    String wrPath = conf.get("fs.snapshot.waitingroom", "/.WR");
    String ssDir = conf.get("fs.snapshot.dir", "/.SNAPSHOT");

    Path foo = new Path("/foo");
    Path bar = new Path("/hadoop/bar");
    Path mash = new Path("/hadoop/mash");

    FSDataOutputStream stream;

    // Create foo
    stream = fs.create(foo);
    stream.writeByte(0);
    stream.close();

    // Move foo to waiting room.
    assertTrue(wr.moveToWaitingRoom(foo));

    // Create snapshot
    ssNode.createSnapshot("first", false); // contains nothing

    // Create bar (V1)
    stream = fs.create(bar);
    stream.write(0);
    stream.close();

    // Create mash (empty)
    stream = fs.create(mash);
    stream.close();

    // Create snapshot
    ssNode.createSnapshot("second", false); // contains bar (V1), mash

    // Move mash, bar to waiting room
    assertTrue(wr.moveToWaitingRoom(mash));
    assertTrue(wr.moveToWaitingRoom(bar));

    // Create bar (V2)
    stream = fs.create(bar);
    stream.write(0);
    stream.close();

    ssNode.createSnapshot("third", false); // contains bar (V2)

    // Verify fs state right now
    assertTrue(fs.exists(bar));
    assertFalse(fs.exists(foo));
    assertFalse(fs.exists(mash));
    assertTrue(fs.exists(new Path(wrPath + "/foo")));
    assertTrue(fs.exists(new Path(wrPath + "/hadoop/bar")));
    assertTrue(fs.exists(new Path(wrPath + "/hadoop/mash")));

    // Run purger
    purger.purge();

    // Verify fs state right now
    assertTrue(fs.exists(bar));
    assertFalse(fs.exists(foo));
    assertFalse(fs.exists(mash));
    assertFalse(fs.exists(new Path(wrPath + "/foo"))); // deleted: unreferenced
    assertTrue(fs.exists(new Path(wrPath + "/hadoop/bar")));
    assertFalse(fs.exists(new Path(wrPath + "/hadoop/mash"))); // deleted: empty

    // Delete snapshot 'second'
    boolean success = fs.delete(new Path(ssDir + "/" + SnapshotNode.SSNAME + "second"));
    assertTrue(success);

    // Run purger again
    purger.purge();

    // Verify fs state right now
    assertTrue(fs.exists(bar));
    assertFalse(fs.exists(foo));
    assertFalse(fs.exists(mash));
    assertFalse(fs.exists(new Path(wrPath + "/foo"))); // deleted: last run
    assertFalse(fs.exists(new Path(wrPath + "/hadoop/bar"))); // deleted: unreferenced
    assertFalse(fs.exists(new Path(wrPath + "/hadoop/mash"))); // deleted: last run
}

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