本文主要包含hdfs读写,hdfs读写流程,hdfs中读写文件实验,hdfs读写原理,java读取hdfs文件等服务器相关知识,网友希望可以进行参考
java读写hdfs简单demo，javahdfsdemo
环境：eclipse + eclipse hadoop插件， hadoop + rhel6.4
package test;
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;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;;
public class Test {
public void WriteFile(String hdfs) throws IOException {
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(URI.create(hdfs),conf);
FSDataOutputStream hdfsOutStream = fs.create(new Path(hdfs));
hdfsOutStream.writeChars("hello");
hdfsOutStream.close();
fs.close();
}
public void ReadFile(String hdfs) throws IOException {
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(URI.create(hdfs),conf);
FSDataInputStream hdfsInStream = fs.open(new Path(hdfs));
byte[] ioBuffer = new byte[1024];
int readLen = hdfsInStream.read(ioBuffer);
while(readLen!=-1)
{
System.out.write(ioBuffer, 0, readLen);
readLen = hdfsInStream.read(ioBuffer);
}
hdfsInStream.close();
fs.close();
}
public static void main(String[] args) throws IOException {
String hdfs = "hdfs://192.168.56.112:9000/test/hello.txt";
Test t = new Test();
t.WriteFile(hdfs);
t.ReadFile(hdfs);
}
}