What are the commonly used I/O data flow tools in Java function libraries?

The I/O data flow tools in the Java function library mainly include: InputStream: abstract input stream OutputStream: abstract output stream FileInputStream: read bytes from the file FileOutputStream: write bytes to the file ByteArrayInputStream: read from the byte array Get bytes ByteArrayOutputStream: Write bytes to byte array BufferedInputStream: Input stream with buffer, improve performance BufferedOutputStream: Output stream with buffer, improve performance DataInputStream: Read basic data types from input stream DataOutputStream: To output stream Writing basic data types

Commonly used I/O data flow tools in Java function libraries

Introduction

Data flow tools are used in Java to process binary data and are very useful in input/output (I/O) operations. The Java function library provides multiple I/O data flow tools. This article will introduce the most commonly used tools and provide practical cases.

Commonly used data flow tools

Read bytes from byte arrayWrite bytes to byte arrayBuffered input stream to improve performanceBuffered output stream to improve performanceRead basic data types from the input streamWrite basic data types to the output stream

Tool	Description
InputStream	Abstract input stream
OutputStream	Abstract output Stream
FileInputStream	Read bytes from file
FileOutputStream	Write bytes to file
##ByteArrayInputStream
ByteArrayOutputStream
BufferedInputStream
BufferedOutputStream
DataInputStream
DataOutputStream

Practical case

Read text file

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();
        }
    }
}

Write to text file

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();
        }
    }
}

Read basic data types from byte array

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();
        }
    }
}

Write basic data types to byte array

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();
        }
    }
}

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