1、hadoop命令
安装在本地的参考文件:hadoop-2.8.5/share/doc/hadoop/hadoop-project-dist/hadoop-common/FileSystemShell.html
比如,创建目录:
mkdir
Usage: hadoop fs -mkdir [-p]
2、API创建目录
2.1、测试类
package test.myhadoop;
import java.io.IOException;
import java.net.URI;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
public class TestHDFS {
FileSystem fs = null;
public void init() throws Exception {
Configuration conf = new Configuration();
conf.set("fs.defaultFS", "hdfs://cos6743:9000");
fs = FileSystem.get(URI.create("/"), conf, "root");
}
public void close() {
try {
if (fs != null) {
fs.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
public void mkdirs() {
try {
fs.mkdirs(new Path("/user/test"));
} catch (IOException e) {
System.out.println("-- IOException --");
e.printStackTrace();
}
}
public static void main(String[] args) {
TestHDFS hdfs = new TestHDFS();
try {
hdfs.init();
hdfs.mkdirs();
} catch (Exception e) {
e.printStackTrace();
}
}
}
2.2运行前后结果查看
命令:hadoop fs -ls /
测试类执行前,列表为空;执行后,可以看到创建的目录