learn-go-hdfs-write.go

// This simple program shows how to use the write-support branch of                                                                                                                                                                                                                                                                                                       
// https://github.com/colinmarc/hdfs/, which accesses HDFS of Hadoop                                                                                                                                                                                                                                                                                                      
// 2.2.x throught the native protobuf-based RPC protocol                                                                                                                                                                                                                                                                                                                  
package main                                                                                                                                                                                                                                                                                                                                                              

import (                                                                                                                                                                                                                                                                                                                                                                  
        "flag"                                                                                                                                                                                                                                                                                                                                                            
        "fmt"                                                                                                                                                                                                                                                                                                                                                             
        "log"                                                                                                                                                                                                                                                                                                                                                             

        "github.com/colinmarc/hdfs"                                                                                                                                                                                                                                                                                                                                       
)                                                                                                                                                                                                                                                                                                                                                                         

func main() {                                                                                                                                                                                                                                                                                                                                                             
        namenode := flag.String("namenode", "localhost:9000", "Address of HDFS namenode")                                                                                                                                                                                                                                                                                 
        flag.Parse()                                                                                                                                                                                                                                                                                                                                                      

        dfs, e := hdfs.New(*namenode)                                                                                                                                                                                                                                                                                                                                     
        if e != nil {                                                                                                                                                                                                                                                                                                                                                     
                log.Fatal(e)                                                                                                                                                                                                                                                                                                                                              
        }                                                                                                                                                                                                                                                                                                                                                                 
        w, e := dfs.Create("/hello.txt")                                                                                                                                                                                                                                                                                                                                  
        if e != nil {                                                                                                                                                                                                                                                                                                                                                     
                log.Fatal(e)                                                                                                                                                                                                                                                                                                                                              
        }                                                                                                                                                                                                                                                                                                                                                                 
        r, e := w.Write([]byte("Hello, World!\n"))                                                                                                                                                                                                                                                                                                                        
        if e != nil {                                                                                                                                                                                                                                                                                                                                                     
                log.Fatal(e)                                                                                                                                                                                                                                                                                                                                              
        }                                                                                                                                                                                                                                                                                                                                                                 
        fmt.Println("written ", r)                                                                                                                                                                                                                                                                                                                                        
        w.Close()                                                                                                                                                                                                                                                                                                                                                         
}