Hadoop的API操作

package www.hadoophdfs;

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

import org.apache.commons.io.IOUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.LocatedFileStatus;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.RemoteIterator;

public class HDFSDemo {
// 文件上传
public void upload() throws IOException, InterruptedException, URISyntaxException {
// 获取配置文件 加载配置文件 core-site.xml core-default.xml
Configuration conf = new Configuration();
// conf.set(“dfs.replication”, “10”);
// 获取FileSystem对象
FileSystem fs = FileSystem.get(new URI(“hdfs://192.168.4.158:9000”), conf, “root”);
Path src = new Path(“D:/aa.txt”);
Path dst = new Path(“/aa”);
fs.copyFromLocalFile(src, dst);
fs.close();
System.out.println(“上传成功”);
}

// 文件下载public void download() throws IOException, InterruptedException, URISyntaxException {    // 获取配置文件 加载配置文件 core-site.xml core-default.xml    Configuration conf = new Configuration();    // 获取FileSystem对象    FileSystem fs = FileSystem.get(new URI("hdfs://192.168.4.158:9000"), conf, "root");    Path dst = new Path("/e");    FSDataInputStream in = fs.open(dst);    FileOutputStream fos = new FileOutputStream("E:\\data1.java");    int n = -1;    while ((n = in.read()) != -1) {        System.out.println((char) n);        fos.write(n);    }    // for(int i=0;i<3;i++){    // System.out.println((char)in.read());    // }    fs.close();    System.out.println("下载成功");}// 创建目录public void mkdirs() throws IOException, InterruptedException, URISyntaxException {    // 获取配置文件，加载配置文件core-size.xml core-default.xml    Configuration conf = new Configuration();    // 获取fs对象    FileSystem fs = FileSystem.get(new URI("hdfs://192.168.4.158:9000"), conf, "root");    fs.mkdirs(new Path("/c"));    fs.close();    System.out.println("创建成功！");}// 删除目录public void delete() throws IllegalArgumentException, IOException, InterruptedException, URISyntaxException {    // 获取配置文件    Configuration conf = new Configuration();    // 获取fs对象    FileSystem fs = FileSystem.get(new URI("hdfs://192.168.4.158:9000"), conf, "root");    fs.delete(new Path("/aa"), 1 > 0);// 1>0==true    // fs.delete(new Path("/aa"));    fs.close();    System.out.println("删除成功");}// 查看目录public void cat() throws IOException, InterruptedException, URISyntaxException {    // 获取配置文件    Configuration conf = new Configuration();    // 获取对象    FileSystem fs = FileSystem.get(new URI("hdfs://192.168.4.158:9000"), conf, "root");    // RemoteIterator<LocatedFileStatus> rm=fs.listFiles(new Path("/"),    // true);    // while(rm.hasNext()){    // LocatedFileStatus lfs=rm.next();    // System.out.println(lfs);    // }    RemoteIterator<LocatedFileStatus> rm = fs.listLocatedStatus(new Path("/"));    while (rm.hasNext()) {        LocatedFileStatus lfs = rm.next();        System.out.println(lfs);    }    fs.close();    System.out.println("查看目录");}// 流的操作--上传文件public void streamUp() throws IOException, InterruptedException, URISyntaxException {    // 获取配置文件    Configuration conf = new Configuration();    // 获取fs对象    FileSystem fs = FileSystem.get(new URI("hdfs://192.168.4.158:9000"), conf, "root");    FileInputStream fis = new FileInputStream("E:\\java\\视频资源2\\9\\www\\1.java");    FSDataOutputStream out = fs.create(new Path("/e"));    IOUtils.copy(fis, out);    System.out.println("上传成功--流的操作");}// 流的操作--下载文件public void streanLoca() throws IOException, InterruptedException, URISyntaxException {    // 获取配置文件    Configuration conf = new Configuration();    // 获取fs对象    FileSystem fs = FileSystem.get(new URI("hdfs://192.168.4.158:9000"), conf, "root");    // 创建输出流--写到本地磁盘    FileOutputStream fos = new FileOutputStream("F:\\xiazai\\3.java");    // 创建输入流--读取服务器上的内容    FSDataInputStream in = fs.open(new Path("/e"));    in.seek(2000);// 去除2000个字节（从前面开始去除）    IOUtils.copy(in, fos);    System.out.println("流的方式--下载成功");}public static void main(String[] args) throws IOException, InterruptedException, URISyntaxException {    HDFSDemo hd = new HDFSDemo();    // hd.upload();    // hd.mkdirs();    // hd.delete();    // hd.cat();    // hd.streamUp();    // hd.streanLoca();    hd.download();}

}