FileInputStream的使用及其方法

1. FileInputStream:文件输入流

read方法详解：
1.

在读取完毕之后，应该要关闭文件。

    @Test
    public void fileinputstream(){
        String path = "D:\opop.txt";
        int readdata = 0;
        FileInputStream fileInputStream = null;
        try {
            fileInputStream = new FileInputStream(path);
            while((readdata = fileInputStream.read()) != -1){
                System.out.println((char)readdata);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                fileInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

该方法最终返回实际读取的总字节数。

    @Test
    public void fileinputstream(){
        java.lang.String path = "D:\opop.txt";
        byte buf[] = new byte [3];
        int readLength ;
        FileInputStream fileInputStream = null;
        try {
           fileInputStream = new FileInputStream(path);
            while((readLength = fileInputStream.read(buf)) != -1){
                java.lang.String a = new java.lang.String(buf,0,readLength);
                System.out.println(a);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                fileInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}