Hadoop.2.x_简单的测试文件读取与上传

代码如下, 后备参考:

package com.bigdata.hadoop.hdfs;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

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.Path;
import org.apache.hadoop.io.IOUtils;
import org.junit.Test;

public class HdfsTest {
	
	public static FileSystem getFileSystem() throws IOException{

		Configuration configuration = new Configuration();
		//Some configurations used to replace the configuration of resource files
		//configuration.set("fs.defaultFS", "hdfs://linux-66-64.liuwl.com:8020");
		//...
		return FileSystem.get(configuration);
	}

	@Test
	public static void read() throws IOException{
		
		String fileName = "/user/liuwl/tmp/core-site.xml";
		FileSystem fileSystem = getFileSystem();
		Path path = new Path(fileName);
		FSDataInputStream instream = fileSystem.open(path);
		try{
			IOUtils.copyBytes(instream, System.out, 4896,false);
		}catch(Exception e){
			e.getStackTrace();
		}finally{
			IOUtils.closeStream(instream);
		}
	}
	
	@Test
	public void write() throws IOException{
		
		String fileName = "/user/liuwl/tmp/input/wc.input";
		FileSystem fileSystem = getFileSystem();
		Path writePath = new Path(fileName);
		FSDataOutputStream outStream = fileSystem.create(writePath);
		FileInputStream inStream = new FileInputStream(new File("/home/liuwl/opt/data/wc.input"));
		try{
			IOUtils.copyBytes(inStream, outStream, 4896,false);
		}catch(Exception e){
			e.getStackTrace();
		}finally{
			IOUtils.closeStream(inStream);
			IOUtils.closeStream(outStream);
		}
	}
}