Java 函数库中都有哪些常用 I/O 数据流工具？

import java.io.FileInputStream;
import java.io.IOException;

public class ReadTextFile {

    public static void main(String[] args) {
        try (FileInputStream fis = new FileInputStream("myfile.txt")) {
            // 逐字节读取文件
            int c;
            while ((c = fis.read()) != -1) {
                System.out.print((char) c);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.FileOutputStream;
import java.io.IOException;

public class WriteTextFile {

    public static void main(String[] args) {
        try (FileOutputStream fos = new FileOutputStream("myfile.txt")) {
            // 写入文本
            String text = "Hello, world!";
            fos.write(text.getBytes());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;

public class ReadBasicTypesFromBytes {

    public static void main(String[] args) {
        // 定义字节数组并写入基本数据类型
        byte[] bytes = {1, 2, 3, 4};
        ByteArrayInputStream bis = new ByteArrayInputStream(bytes);
        DataInputStream dis = new DataInputStream(bis);

        try {
            // 读取基本数据类型
            int i = dis.readInt();
            System.out.println("Int: " + i);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;

public class WriteBasicTypesToBytes {

    public static void main(String[] args) {
        // 创建字节数组输出流
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        DataOutputStream dos = new DataOutputStream(bos);

        try {
            // 写入基本数据类型
            dos.writeInt(12345);
            dos.flush();
            // 获取字节数组
            byte[] bytes = bos.toByteArray();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}