java_hdfs之读写文件

package hdfsTest.answer.hdfs;
 
import java.io.IOException;
import java.net.URI;
//import java.net.URLDecoder;
 
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;
 
public class HDFSTest {
 
    public static void main(String[] args) throws IOException {
 
        System.out.println("execute start!!!");
 
        String file = "hdfs://hadoop1:9000/linjm/hdfsTest.txt";
        String str = "hello world 你好 HA Welcome!!!\n Java.\n";
 
        HDFSTest t = new HDFSTest();
        t.writeFile(file, str);
        t.readFile(file);
 
        System.out.println("execute end!!!");
    }
 
    public void readFile(String file) throws IOException {
        Configuration conf = new Configuration();
        FileSystem fs = FileSystem.get(URI.create(file), conf);
        FSDataInputStream hdfsIS = fs.open(new Path(file));
 
        byte[] ioBuffer = new byte[1024];
        int readLen = hdfsIS.read(ioBuffer);
        while (readLen != -1) {
            System.out.write(ioBuffer, 0, readLen);
            readLen = hdfsIS.read(ioBuffer);
        }
        hdfsIS.close();
        fs.close();
    }
 
    public void writeFile(String file, String str) throws IOException {
        Configuration conf = new Configuration();
        FileSystem fs = FileSystem.get(URI.create(file), conf);
        System.out.println("路径是否存在:" + fs.exists(new Path(file)));
        FSDataOutputStream hdfsOS = fs.create(new Path(file));
//        hdfsOS.writeChars(URLDecoder.decode(str, "UTF-8"));
        hdfsOS.write(str.getBytes(), 0, str.getBytes().length);
        hdfsOS.close();
        fs.close();
    }
 
}