golang之常用方法/函数

1. io.Reader转化为字符串, byte切片

import "bytes"

func StreamToByte(stream io.Reader) []byte {
  buf := new(bytes.Buffer)
    buf.ReadFrom(stream)
    return buf.Bytes()
}

func StreamToString(stream io.Reader) string {
    buf := new(bytes.Buffer)
    buf.ReadFrom(stream)
    return buf.String()
}

示例:

1) byte切片转io.Reader
package main

import (
  "bytes"
  "log"
)

func main() {
  data := []byte("this is some data stored as a byte slice in Go Lang!")

  // convert byte slice to io.Reader
  reader := bytes.NewReader(data)

  // read only 4 byte from our io.Reader
  buf := make([]byte, 4)
  n, err := reader.Read(buf)
  if err != nil {
    log.Fatal(err)
  }
  log.Println(string(buf[:n]))
}

2) io.Reader转byte切片
package main

import (
  "bytes"
  "log"
  "strings"
)

func main() {
  ioReaderData := strings.NewReader("this is some data stored as a byte slice in Go Lang!")

  // creates a bytes.Buffer and read from io.Reader
  buf := &bytes.Buffer{}
  buf.ReadFrom(ioReaderData)

  // retrieve a byte slice from bytes.Buffer
  data := buf.Bytes()

  // only read the first 4 bytes
  log.Println(string(data[:4]))
}