关于文件输入流

构造方法摘要

方法摘要

示例代码

1、读取文件内容

import java.io.FileInputStream;
import java.io.IOException;
public class Main {
    public static void main(String[] args) {
//        readFile01();
        readFile02();
    }
    /**
     * 一次读取一个字节，效率比较低
     */
    public static void readFile01() {
        String filePath = "./hello.txt";
        int data = 0;
        FileInputStream fileInputStream = null;
        try {
            fileInputStream = new FileInputStream(filePath);
            while ((data = fileInputStream.read()) != -1) {
                System.out.print((char) data);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭文件流，释放资源。。，。，。．
            try {
                fileInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    /**
     * 一次读取 8 个字节
     */
    public static void readFile02() {
        String filePath = "./hello.txt";
        int readLen = 0;
        byte[] buf = new byte[8];
        FileInputStream fileInputStream = null;
        try {
            fileInputStream = new FileInputStream(filePath);
            while ((readLen = fileInputStream.read(buf)) != -1) {
                System.out.print(new String(buf, 0, readLen));
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭文件流，释放资源。。，。，。．
            try {
                fileInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}