Java I/O 教程（四） FileInputStream 类

Java FileInputStream class 从一个文件读取字节数据。
用于从图像，音频，视频等文件中读取字节类型数据。

类定义

public class FileInputStream extends InputStream

常用构造函数

FileInputStream(File file)
Creates a FileInputStream by opening a connection to an actual file, the file named by the File object file in the file system

FileInputStream(String name)
Creates a FileInputStream by opening a connection to an actual file, the file named by the path name name in the file system.

常用方法

int available()                           返回输入流中可读取的字节大小
int read()                               从输入流读取字节
int read(byte[] b)                       从输入流读取b.length长度的字节
int read(byte[] b, int off, int len)   从输入流每次读取b.length长度的字节
void close()                           关闭文件输入流

例子1

package com.dylan.io;

import java.io.FileInputStream;

/**
 * @author xusucheng
 * @create 2017-12-31
 **/
public class FileInputStreamReadAllChars {
    public static void main(String[] args) {
        try {
            FileInputStream fin = new FileInputStream("d:\\testout.txt");
            int i=0;
            while ((i=fin.read())!=-1){
                System.out.print((char) i);
            }
            fin.close();
        } catch (java.io.IOException e) {
            e.printStackTrace();
        }
    }
}