Hadoop 用命令行编译URLCat

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;

import org.apache.hadoop.fs.FsUrlStreamHandlerFactory;
import org.apache.hadoop.io.IOUtils;

public class URLCat {
static{
URL.setURLStreamHandlerFactory(new FsUrlStreamHandlerFactory());
}
public static void main(String args[]) throws Exception{
InputStream in = null;
try{
in = new URL(args[0]).openStream();
IOUtils.copyBytes(in, System.out, 4096, false);
}finally{
IOUtils.closeStream(in);
}
}
}

编译

javac -classpath hadoop-core-1.1.2.jar -d secondProject secondProject/URLCat.java

生成JAR

jar -cvf URLCat.jar -C secondProject/ .

hadoop jar URLCat.jar URLCat hdfs://localhost:49000/user/hadoop/input/file01

路径根据

fs.default.name
hdfs://localhost:49000

调整