java _io_ .read（）分段讀取字節(jié)

byte[] flush =new byte[n] //字節(jié)數(shù)組充當(dāng)緩沖容器
.read(flush) //每次返回讀取的n個字節(jié)，當(dāng)數(shù)據(jù)字節(jié)數(shù)不夠時，返回實際字節(jié)數(shù)
int len=-1; //接受read（flush）返回的實際長度
String s= new String(flush,0,len) //解碼操作，len必須為實際大小，否則多余長度會返回垃圾字符

public static void main(String[]args) 
{
    //創(chuàng)建源
    File f=new File("C:/Users/10853/eclipse-workspace/hell/src/hell/abc");
    InputStream is =null;

    //選擇流
    try {
         is =new FileInputStream(f);
    //操作(讀取),分段讀取   
        byte[] flush =new byte[3]; //緩沖容器
        int len=-1; //接收長度
        while((len=is.read(flush))!=-1) //is.read(car)每次讀取三個字節(jié)，讀取完畢會返回-1,
                                        //當(dāng)數(shù)據(jù)不夠3時，將返回實際數(shù)據(jù)個數(shù)
        {                           
            String s =new String(flush,0,len); //必須返回實際的大小，否則多余的長度會返回垃圾字符
            System.out.println(s);
        }

    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }finally
    {
        try {
            if(null!=is)
            {
                is.close();
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}