Hadoop基础-04-HDFS API编程

源码见：https://github.com/hiszm/hadoop-train

HDFS API编程

开发环境搭建

porn.xml

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.example</groupId>
  <artifactId>untitled4</artifactId>
  <version>1.0-SNAPSHOT</version>

  <name>untitled4</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>



  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
    <hadoop.version>2.6.0-cdh5.15.1</hadoop.version>
  </properties>



  <repositories>
    <repository>
      <id>cloudera</id>
      <url>https://repository.cloudera.com/artifactory/cloudera-repos/</url>
    </repository>
  </repositories>

  <dependencies>

    <dependency>
      <groupId>org.apache.hadoop</groupId>
      <artifactId>hadoop-client</artifactId>
      <version>2.6.0-cdh5.15.1</version>
    </dependency>

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

  </dependencies>

  <build>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
        <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
        <plugin>
          <artifactId>maven-site-plugin</artifactId>
          <version>3.7.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-project-info-reports-plugin</artifactId>
          <version>3.0.0</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

等下载完毕就可以了

最后速度太慢,我就挂梯子了

这个就是安装完毕后的样子

HelloWorld

package org.example;

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

import java.net.URI;

//使用java API来操作文件系统
public class HDFSapp {

    public static void main(String[] args) throws Exception {
        Configuration configuration =new Configuration();

        FileSystem fileSystem= FileSystem.get(new URI("hdfs://hadoop000:8020"), configuration);
        Path path= new Path("/hdfsapi/test");
        boolean result= fileSystem.mkdirs(path);
        System.out.println(result);
    }

}

第一次出现了报错Permission denied

Exception in thread "main" org.apache.hadoop.security.AccessControlException: Permission denied: user=jacksun, access=WRITE, inode="/":hadoop:supergroup:drwxr-xr-x
	at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.checkFsPermission(DefaultAuthorizationProvider.java:279)
	at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.chec

-rw-r--r--   1 hadoop supergroup       1366 2020-08-17 21:35 /README.txt
drwxr-xr-x   - hadoop supergroup          0 2020-08-17 21:48 /hdfs-test
-rw-r--r--   1 hadoop supergroup  181367942 2020-08-17 21:59 /jdk-8u91-linux-x64.tar.gz

原因我们不是supergroup组里面的没有写权限

解决办法加入用户hadoop到里面

package org.example;

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

import java.net.URI;

//使用java API来操作文件系统
public class HDFSapp {

    public static void main(String[] args) throws Exception {
        Configuration configuration =new Configuration();
        FileSystem fileSystem= FileSystem.get(new URI("hdfs://hadoop000:8020"), configuration, "hadoop");
        Path path= new Path("/hdfsapi/test");
        boolean result= fileSystem.mkdirs(path);
        System.out.println(result);
    }

}

true

Process finished with exit code 0

[hadoop@hadoop000 sbin]$ hadoop fs -ls /
Found 4 items
-rw-r--r--   1 hadoop supergroup       1366 2020-08-17 21:35 /README.txt
drwxr-xr-x   - hadoop supergroup          0 2020-08-17 21:48 /hdfs-test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi
-rw-r--r--   1 hadoop supergroup  181367942 2020-08-17 21:59 /jdk-8u91-linux-x64.tar.gz

jUnit封装

package org.example;

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

import java.net.URI;

//使用java API来操作文件系统
public class HDFSapp {

    public static final String HDFS_PATH="hdfs://hadoop000:8020";
    FileSystem fileSystem=null;
    Configuration configuration=null;


    @Before
    public void setUp() throws Exception{
        System.out.println("=======setUp=======");
        //fileSyetem参数(指定uri,客户端指定的配置参数,客户端的身份即用户名)
        configuration=new Configuration();
        fileSystem=FileSystem.get(new URI(HDFS_PATH),configuration,"hadoop");
    }
    @Test
    public void mkdir() throws Exception{
        fileSystem.mkdirs(new Path("/hdfsapi/test2"));
    }

    @After
    public void tearDown(){
        configuration=null;
        fileSystem=null;
        System.out.println("=======tearDown=======");

    }


//    public static void main(String[] args) throws Exception {
//        Configuration configuration =new Configuration();
//        FileSystem fileSystem= FileSystem.get(new URI("hdfs://hadoop000:8020"), configuration, "hadoop");
//        Path path= new Path("/hdfsapi/test");
//        boolean result= fileSystem.mkdirs(path);
//        System.out.println(result);
//    }

}

[hadoop@hadoop000 sbin]$ hadoop fs -ls /hdfsapi
Found 2 items
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi/test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:44 /hdfsapi/test2

查看HDFS文件内容

 //查看HDFS内容
    @Test
    public void text() throws Exception{
        FSDataInputStream in=fileSystem.open(new Path("/README.txt"));
        IOUtils.copyBytes(in,System.out,1024);

    }

创建文件

 //创建文件
    @Test
    public void create() throws Exception{
        FSDataOutputStream out=fileSystem.create(new Path("/hdfsapi/b.txt"));
        out.writeUTF("hello world replication");
        out.flush();
        out.close();
    }

[hadoop@hadoop000 sbin]$ hadoop dfs -ls /hdfsapi
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.

Found 4 items
-rw-r--r--   1 hadoop supergroup         25 2020-08-21 09:48 /hdfsapi/b.txt
-rw-r--r--   3 hadoop supergroup         13 2020-08-19 10:07 /hdfsapi/c.txt
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi/test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:44 /hdfsapi/test2
[hadoop@hadoop000 sbin]$ 

副本系数剖析

[hadoop@hadoop000 sbin]$ hadoop fs -ls /
Found 4 items
-rw-r--r--   1 hadoop supergroup       1366 2020-08-17 21:35 /README.txt
drwxr-xr-x   - hadoop supergroup          0 2020-08-17 21:48 /hdfs-test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 10:07 /hdfsapi
-rw-r--r--   1 hadoop supergroup  181367942 2020-08-17 21:59 /jdk-8u91-linux-x64.tar.gz
[hadoop@hadoop000 sbin]$ hadoop fs -ls /hdfsapi
Found 3 items
-rw-r--r--   3 hadoop supergroup         13 2020-08-19 10:07 /hdfsapi/a.txt
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi/test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:44 /hdfsapi/test2

我们发现一个细节
是用ssh在服务器上创建的文件副本系数有1个

但是使用java创建的副本系数创建的副本洗漱有3个

那是因为在idea的配置里面我们设置的是3个

在代码中添加下面的 configuration.set("dfs.replication","1");
可以实现对副本洗漱的控制

    @Before
    public void setUp() throws Exception{
        System.out.println("=======setUp=======");
        //fileSyetem参数(指定uri,客户端指定的配置参数,客户端的身份即用户名)
        configuration=new Configuration();
        configuration.set("dfs.replication","1");
        fileSystem=FileSystem.get(new URI(HDFS_PATH),configuration,"hadoop");
    }

[hadoop@hadoop000 hadoop]$ hadoop fs -ls /hdfsapi
Found 4 items
-rw-r--r--   3 hadoop supergroup         13 2020-08-19 10:07 /hdfsapi/a.txt
-rw-r--r--   1 hadoop supergroup          0 2020-08-19 10:46 /hdfsapi/b.txt
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi/test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:44 /hdfsapi/test2

重命名

//重命名
    @Test
    public void rename() throws Exception{
        Path oldPath=new Path("/hdfsapi/a.txt");
        Path newPath=new Path("/hdfsapi/c.txt");
        boolean result =fileSystem.rename(oldPath,newPath);
        System.out.println(result);
    }

[hadoop@hadoop000 sbin]$ hadoop fs -ls /hdfsapi/
Found 4 items
-rw-r--r--   3 hadoop supergroup         13 2020-08-19 10:07 /hdfsapi/a.txt
-rw-r--r--   1 hadoop supergroup         25 2020-08-19 10:46 /hdfsapi/b.txt
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi/test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:44 /hdfsapi/test2
[hadoop@hadoop000 sbin]$ hadoop fs -ls /hdfsapi/
Found 4 items
-rw-r--r--   1 hadoop supergroup         25 2020-08-19 10:46 /hdfsapi/b.txt
-rw-r--r--   3 hadoop supergroup         13 2020-08-19 10:07 /hdfsapi/c.txt
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi/test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:44 /hdfsapi/test2

上传本地文件到HDFS

    //上传本地文件到HDFS系统
    @Test
    public void copyFromLocalFile() throws Exception{
        Path src =new Path("/Users/jacksun/data/local.txt");
        Path dst =new Path("/hdfsapi/");
        fileSystem.copyFromLocalFile(src,dst);
    }

[hadoop@hadoop000 sbin]$ hadoop dfs -ls /hdfsapi
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.

Found 4 items
-rw-r--r--   1 hadoop supergroup         25 2020-08-21 09:48 /hdfsapi/b.txt
-rw-r--r--   3 hadoop supergroup         13 2020-08-19 10:07 /hdfsapi/c.txt
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi/test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:44 /hdfsapi/test2
[hadoop@hadoop000 sbin]$ hadoop dfs -ls /hdfsapi
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.

Found 5 items
-rw-r--r--   1 hadoop supergroup         25 2020-08-21 09:48 /hdfsapi/b.txt
-rw-r--r--   3 hadoop supergroup         13 2020-08-19 10:07 /hdfsapi/c.txt
-rw-r--r--   1 hadoop supergroup         18 2020-08-21 09:52 /hdfsapi/local.txt
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi/test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:44 /hdfsapi/test2

带进度的上传大文件

    //上传本地文件到HDFS系统(大文件,进度条)
    @Test
    public void copyFromLocalBigFile() throws Exception{
        InputStream in =new BufferedInputStream(new FileInputStream(new File("/Users/jacksun/data/music.ape")));
        FSDataOutputStream out =fileSystem.create(new Path("/hdfsapi/music.ape"),
                new Progressable() {
                    @Override
                    public void progress() {
                        System.out.print("-");
                    }
                }
        );
        IOUtils.copyBytes(in,out,1024);
    }

[hadoop@hadoop000 sbin]$ hadoop dfs -ls /hdfsapi
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.

Found 6 items
-rw-r--r--   1 hadoop supergroup         25 2020-08-21 09:48 /hdfsapi/b.txt
-rw-r--r--   3 hadoop supergroup         13 2020-08-19 10:07 /hdfsapi/c.txt
-rw-r--r--   1 hadoop supergroup         18 2020-08-21 09:52 /hdfsapi/local.txt
-rw-r--r--   1 hadoop supergroup   48097077 2020-08-21 09:52 /hdfsapi/music.ape
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi/test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:44 /hdfsapi/test2

下载文件

    // 从HDFS系统下载文件到本地
    @Test
    public void copyToLocalFile() throws Exception{
        Path src =new Path("/hdfsapi/hello.txt");
        Path dst =new Path("/Users/jacksun/data");
        fileSystem.copyFromLocalFile(src,dst);

    }

列出文件夹下的所有内容

 //列出文件列表
    @Test
    public void listFiles() throws Exception {
        FileStatus[] statuses = fileSystem.listStatus(new Path("/hdfsapi"));
        for (FileStatus file : statuses) {
            printFileStatus(file);
        }
    }

    private void printFileStatus(FileStatus file) {
        String isDir = file.isDirectory() ? "文件夹" : "文件";
        String permission = file.getPermission().toString();
        short replication = file.getReplication();
        long length = file.getLen();
        String path = file.getPath().toString();

        System.out.println(isDir + "\t" + permission + "\t" +
                replication + "\t" + length + "\t" + path);
    }

=======setUp=======
log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
文件	rw-r--r--	1	25	hdfs://hadoop000:8020/hdfsapi/b.txt
文件	rw-r--r--	3	13	hdfs://hadoop000:8020/hdfsapi/c.txt
文件	rw-r--r--	1	18	hdfs://hadoop000:8020/hdfsapi/local.txt
文件	rw-r--r--	1	48097077	hdfs://hadoop000:8020/hdfsapi/music.ape
文件夹	rwxr-xr-x	0	0	hdfs://hadoop000:8020/hdfsapi/test
文件夹	rwxr-xr-x	0	0	hdfs://hadoop000:8020/hdfsapi/test2
=======tearDown=======

递归列出文件夹下的所有文件

    //递归列出所有文件
    @Test
    public void listFileRecursive() throws Exception {
        RemoteIterator<LocatedFileStatus> files = fileSystem.listFiles(
                new Path("/hdfsapi"), true);
        while (files.hasNext()) {
            LocatedFileStatus file = files.next();
            printFileStatus(file);
        }
    }

=======setUp=======
log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
文件	rw-r--r--	1	25	hdfs://hadoop000:8020/hdfsapi/b.txt
文件	rw-r--r--	3	13	hdfs://hadoop000:8020/hdfsapi/c.txt
文件	rw-r--r--	1	18	hdfs://hadoop000:8020/hdfsapi/local.txt
文件	rw-r--r--	1	48097077	hdfs://hadoop000:8020/hdfsapi/music.ape

查看文件块信息

     // 查看文件块信息
    @Test
    public void getFielBlockLocations() throws Exception {
        FileStatus fileStatus = fileSystem.getFileStatus(
                new Path("/hdfsapi/test/a.txt"));
        BlockLocation[] blocks = fileSystem.getFileBlockLocations(fileStatus,
                0, fileStatus.getLen());

        for (BlockLocation block : blocks) {
            for (String name : block.getNames()) {
                System.out.println(name + ":" + block.getOffset() + ":" +
                        block.getLength() + ":" + block.getHosts());
            }
        }
    }

删除文件

    //删除文件
    @Test
    public void delete() throws Exception {
        fileSystem.delete(new Path("/hdfsapi/test/idea.dmg"), true);
    }

Found 6 items
-rw-r--r--   1 hadoop supergroup         25 2020-08-21 09:48 /hdfsapi/b.txt
-rw-r--r--   3 hadoop supergroup         13 2020-08-19 10:07 /hdfsapi/c.txt
-rw-r--r--   1 hadoop supergroup         18 2020-08-21 09:52 /hdfsapi/local.txt
-rw-r--r--   1 hadoop supergroup   48097077 2020-08-21 09:52 /hdfsapi/music.ape
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi/test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:44 /hdfsapi/test2
[hadoop@hadoop000 sbin]$ hadoop dfs -ls /hdfsapi
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.

Found 5 items
-rw-r--r--   1 hadoop supergroup         25 2020-08-21 09:57 /hdfsapi/b.txt
-rw-r--r--   3 hadoop supergroup         13 2020-08-19 10:07 /hdfsapi/c.txt
-rw-r--r--   1 hadoop supergroup   48097077 2020-08-21 09:57 /hdfsapi/music.ape
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:08 /hdfsapi/test
drwxr-xr-x   - hadoop supergroup          0 2020-08-19 09:44 /hdfsapi/test2

所有文件

package org.example;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.*;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.util.Progressable;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.URI;

//使用java API来操作文件系统
public class HDFSapp {

    public static final String HDFS_PATH="hdfs://hadoop000:8020";
    FileSystem fileSystem=null;
    Configuration configuration=null;


    @Before
    public void setUp() throws Exception{
        System.out.println("=======setUp=======");
        //fileSyetem参数(指定uri,客户端指定的配置参数,客户端的身份即用户名)
        configuration=new Configuration();
        configuration.set("dfs.replication","1");
        fileSystem=FileSystem.get(new URI(HDFS_PATH),configuration,"hadoop");
    }

    //创建文件夹
    @Test
    public void mkdir() throws Exception{
        fileSystem.mkdirs(new Path("/hdfsapi/test2"));
    }
    //查看HDFS内容
    @Test
    public void text() throws Exception{
        FSDataInputStream in=fileSystem.open(new Path("/README.txt"));
        IOUtils.copyBytes(in,System.out,1024);

    }
    //========================================
    //创建文件
    @Test
    public void create() throws Exception{
        FSDataOutputStream out=fileSystem.create(new Path("/hdfsapi/b.txt"));
        out.writeUTF("hello world replication");
        out.flush();
        out.close();
    }
    //重命名
    @Test
    public void rename() throws Exception{
        Path oldPath=new Path("/hdfsapi/a.txt");
        Path newPath=new Path("/hdfsapi/c.txt");
        boolean result =fileSystem.rename(oldPath,newPath);
        System.out.println(result);
    }
    //上传本地文件到HDFS系统
    @Test
    public void copyFromLocalFile() throws Exception{
        Path src =new Path("/Users/jacksun/data/local.txt");
        Path dst =new Path("/hdfsapi/");
        fileSystem.copyFromLocalFile(src,dst);
    }

    //上传本地文件到HDFS系统(大文件,进度条)
    @Test
    public void copyFromLocalBigFile() throws Exception{
        InputStream in =new BufferedInputStream(new FileInputStream(new File("/Users/jacksun/data/music.ape")));
        FSDataOutputStream out =fileSystem.create(new Path("/hdfsapi/music.ape"),
                new Progressable() {
                    @Override
                    public void progress() {
                        System.out.print("-");
                    }
                }
        );
        IOUtils.copyBytes(in,out,1024);
    }

    // 从HDFS系统下载文件到本地
    @Test
    public void copyToLocalFile() throws Exception{
        Path src =new Path("/hdfsapi/hello.txt");
        Path dst =new Path("/Users/jacksun/data");
        fileSystem.copyFromLocalFile(src,dst);

    }

    //列出文件列表
    @Test
    public void listFiles() throws Exception {
        FileStatus[] statuses = fileSystem.listStatus(new Path("/hdfsapi"));
        for (FileStatus file : statuses) {
            printFileStatus(file);
        }
    }

    private void printFileStatus(FileStatus file) {
        String isDir = file.isDirectory() ? "文件夹" : "文件";
        String permission = file.getPermission().toString();
        short replication = file.getReplication();
        long length = file.getLen();
        String path = file.getPath().toString();

        System.out.println(isDir + "\t" + permission + "\t" +
                replication + "\t" + length + "\t" + path);
    }
    //递归列出所有文件
    @Test
    public void listFileRecursive() throws Exception {
        RemoteIterator<LocatedFileStatus> files = fileSystem.listFiles(
                new Path("/hdfsapi"), true);
        while (files.hasNext()) {
            LocatedFileStatus file = files.next();
            printFileStatus(file);
        }
    }




     // 查看文件块信息
    @Test
    public void getFielBlockLocations() throws Exception {
        FileStatus fileStatus = fileSystem.getFileStatus(
                new Path("/hdfsapi/test/a.txt"));
        BlockLocation[] blocks = fileSystem.getFileBlockLocations(fileStatus,
                0, fileStatus.getLen());

        for (BlockLocation block : blocks) {
            for (String name : block.getNames()) {
                System.out.println(name + ":" + block.getOffset() + ":" +
                        block.getLength() + ":" + block.getHosts());
            }
        }
    }

    //删除文件
    @Test
    public void delete() throws Exception {
        fileSystem.delete(new Path("/hdfsapi/local.txt"), true);
    }


    @After
    public void tearDown(){
        configuration=null;
        fileSystem=null;
        System.out.println("=======tearDown=======");

    }


//    public static void main(String[] args) throws Exception {
//        Configuration configuration =new Configuration();
//        FileSystem fileSystem= FileSystem.get(new URI("hdfs://hadoop000:8020"), configuration, "hadoop");
//        Path path= new Path("/hdfsapi/test");
//        boolean result= fileSystem.mkdirs(path);
//        System.out.println(result);
//    }

}