java操作hdfs

1.添加maven依赖，即在pom.xml文件李添加依赖

<?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>HdfsOperate</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-client</artifactId>
            <version>3.2.4</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>2.0.5</version>
        </dependency>
    </dependencies>

</project>

2.添加log4j配置

Log4j.rootLogger=INFO,stdout
Log4j.appender.stdout=org.apache.log4j.ConsoleAppender
Log4j.appender.stdout.Layout=org.apache.log4j.PatternLayout
Log4j.appender.stdout.Layout.ConversionPattern=%d %p [%C] - %m%n
Log4j.appender.Logfile=org.apache.Log4j.FileAppender
Log4j.appender.Logfile.File=target/log.log
Log4j.appender.Logfile.Layout=org.apache.log4j.PatternLayout
Log4j.appender.Logfile.Layout.ConversionPattern=%d %p [%c] -%m%n

3.编写测试案例

package com.hdfs;

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.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;

public class HdfsOperateTest {
    private FileSystem fs;

    @Before
    public void init() throws URISyntaxException, IOException, InterruptedException {
        URI uri = new URI("hdfs://hadoop01:8020");
        Configuration entries = new Configuration();
        String user = "root";
        fs = FileSystem.get(uri, entries, user);
    }

    @Test
    public void testMkdir() throws IOException {
        fs.mkdirs(new Path("/test"));
    }

    @After
    public void clean() throws IOException {
        fs.close();
    }
}

4.运行代码，检查结果

 

 

 

5.项目结构