解压hadoop-2.7.7.tar.gz

　　复制如下三个jar包和lib下所有jar包到项目文件下的lib文件

@Test
public void readListFiles() throws Exception {
// 1 创建配置信息对象
Configuration configuration = new Configuration();

FileSystem fs = FileSystem.get(new URI("hdfs://192.168.0.xxx:9000"),configuration, "root");

// 思考：为什么返回迭代器，而不是List之类的容器  
RemoteIterator<LocatedFileStatus> listFiles = fs.listFiles(new Path("/"), true);

while (listFiles.hasNext()) {  
    LocatedFileStatus fileStatus = listFiles.next();  
    System.out.println(fileStatus.getPath().getName()); //路径  
    System.out.println(fileStatus.getBlockSize());  //块  
    System.out.println(fileStatus.getPermission()); //权限  
    System.out.println(fileStatus.getLen()); //文件大小  
    System.out.println(fileStatus.isFile()); //是不是一个文件  
        System.out.println(fileStatus.isDirectory()); //是不是一个目录

    BlockLocation\[\] blockLocations = fileStatus.getBlockLocations();

    for (BlockLocation bl : blockLocations) {

        System.out.println("block-offset:" + bl.getOffset());

        String\[\] hosts = bl.getHosts();

        for (String host : hosts) {  
            System.out.println(host);  
        }  
    }

    System.out.println("----------------------------");  
}  
}

@Test
public void download() {
Configuration conf=new Configuration();
try
{
FileSystem fileSystem = FileSystem.get(new URI("hdfs://192.168.0.xxx:9000"),conf);
FSDataInputStream in = fileSystem.open(new Path("/upload.txt"));
FileOutputStream out = new FileOutputStream(new File("d://lib//updoad.txt"));
byte[]b=new byte[1024];
int len=0;
while((len=in.read(b))!=-1) {
out.write(b,0,len);
}
in.close();
out.close();
} catch (IOException | URISyntaxException e)
{
// TODO 自动生成的 catch 块
e.printStackTrace();
}

 }

@Test
public void upload() {
Configuration conf=new Configuration();
try
{
FileSystem fileSystem = FileSystem.get(new URI("hdfs://192.168.0.xxx:9000"),conf);
FSDataOutputStream out = fileSystem.create(new Path("/jetbrains-agent.jar"));
FileInputStream in=new FileInputStream(new File("d:\\jetbrains-agent.jar"));
byte[]b=new byte[10240];
int len=0;
while((len=in.read(b))!=-1) {
out.write(b,0,len);
}
in.close();
out.close();
} catch (IOException | URISyntaxException e)
{
// TODO 自动生成的 catch 块
e.printStackTrace();
}
}

@Test
public void mv() {
Configuration conf=new Configuration();
try
{
FileSystem fileSystem = FileSystem.get(new URI("hdfs://192.168.0.xxx:9000"),conf);
fileSystem.rename(new Path("/hdp01"), new Path("/HDP01"));
fileSystem.close();
} catch (IOException | URISyntaxException e)
{
// TODO 自动生成的 catch 块
e.printStackTrace();
}
}

@Test
public void deleteAtHDFS() throws Exception{
// 1 创建配置信息对象
Configuration configuration = new Configuration();

FileSystem fs = FileSystem.get(new URI("hdfs://192.168.0.xxx:9000"),configuration, "root"); 

　　//2 删除文件夹 ，如果是非空文件夹，参数2是否递归删除，true递归
　　fs.delete(new Path("hdfs://192.168.0.xxx:9000/upload/output"), true);

}

@Test
public void mkdirAtHDFS() throws Exception{
// 1 创建配置信息对象
Configuration configuration = new Configuration();

FileSystem fs = FileSystem.get(new URI("hdfs://192.168.0.xxx:9000"),configuration, "root");    

//2 创建目录  
fs.mkdirs(new Path("hdfs://192.168.0.xxx:9000/upload/output"));  
}

@Test
public void findAtHDFS() throws Exception, IllegalArgumentException, IOException{

// 1 创建配置信息对象  
Configuration configuration = new Configuration();

FileSystem fs = FileSystem.get(new URI("hdfs://192.168.0.xxx:9000"),configuration, "root");

// 2 获取查询路径下的文件状态信息  
FileStatus\[\] listStatus = fs.listStatus(new Path("/"));

// 3 遍历所有文件状态  
for (FileStatus status : listStatus) {  
    if (status.isFile()) {  
        System.out.println("f--" + status.getPath().getName());  
    } else {  
        System.out.println("d--" + status.getPath().getName());  
    }  
}  

}