hdfs后台上传文件

HDFS后台端口由 50070 变为9870：

上传一个图片，hdfs地址为：hdfs://localhost:9000/images/33609397.jpg

maven依赖

我使用的是Hadoop3.0.0，所以依赖是

 <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-hdfs</artifactId>
            <version>3.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-hdfs-client</artifactId>
            <version>3.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-common</artifactId>
            <version>3.0.0</version>
        </dependency>  

测试代码

 public class ReadHdfsFileTest {
    public static void main(String[] args) throws IOException {
        Path path= new Path("hdfs://localhost:9000/images/33609397.jpg");
        //加载配置文件
        Configuration conf = new Configuration();
        FileSystem fs = path.getFileSystem(conf);
        FSDataInputStream is = fs.open(path);
        int available = is.available();
        System.out.println(available);
        fs.close();
    }
}  

报错

 Exception in thread "main" org.apache.hadoop.fs.UnsupportedFileSystemException: No FileSystem for scheme "hdfs"
	at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:3266)
	at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:3286)
	at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:123)
	at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:3337)
	at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:3305)
	at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:476)
	at org.apache.hadoop.fs.Path.getFileSystem(Path.java:361)
	at hdfs.ReadHdfsFileTest.main(ReadHdfsFileTest.java:21)
  

其实是缺少类：DistributedFileSystem.class

Hadoop3.0.0已经将这个类从common移动到hadoop-hdfs-client，所以maven新增依赖就可以

 <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-hdfs-client</artifactId>
            <version>3.0.0</version>
        </dependency>  

运行成功

打印结果：

 log4j:WARN See #noconfig for more info.
55076