博客
关于我
流中写入文字和图片
阅读量:792 次
发布时间:2019-03-24

本文共 5371 字,大约阅读时间需要 17 分钟。

Java Networking Guide: String and Image Transmission Optimization

String Encoding and Transmission

In this section, we will explore the efficient way to send and receive strings between client and server using Java networking.

Understanding Encoding

Each character in the string is encoded into a 2-byte array. This ensures that both English and Chinese characters are handled correctly. Here’s how the conversion works:

public static byte[] char2byte(char c) {    byte[] bytes = new byte[2];    bytes[0] = (byte)((c & 0xff)); // Low eight bits    bytes[1] = (byte)((c >> 8) & 0xff); // High eight bits    return bytes;}

This method converts each character to a byte array, facilitating easy transmission.

###Efficient String Transmission

For transmission, send the length first and then the byte array:

public class Client {    public static void main(String[] args) {        try {            Socket socket = new Socket("127.0.0.1", 9090);            OutputStream out = socket.getOutputStream();            InputStream input = socket.getInputStream();            String s = "Greetings!";            out.write(s.length());            byte[] bytes = s.getBytes();            out.write(bytes);            out.flush();        } catch (IOException e) {            e.printStackTrace();        }    }}

The server reads the length and reconstructs the string:

public class Server {    public static void main(String[] args) {        try {            ServerSocket serSocket = new ServerSocket(9090);            Socket ser = serSocket.accept();            System.out.println("Connection successful");            InputStream input = ser.getInputStream();            int len = input.read();            byte[] bytes = new byte[len);            input.read(bytes);            String received = new String(bytes);            System.out.println("Received: " + received);        } catch (IOException e) {            e.printStackTrace();        }    }}

Method One: Character-by-Character Conversion

This approach ensures that each character is converted and transmitted independently, avoiding byte array complexity.

Method Two: Utilizing Built-in Methods

Java provides simple methods to handle string conversion, making the implementation straightforward:

public class Client {    public static void main(String[] args) {        try {            Socket socket = new Socket("127.0.0.1", 9090);            OutputStream out = socket.getOutputStream();            InputStream input = socket.getInputStream();            String s = "HelloWorld";            byte[] data = s.getBytes();            out.write(data.length);            out.write(data);            out.flush();        } catch (IOException e) {            e.printStackTrace();        }    }}

The server reconstructs the string using the byte array:

public class Server {    public static void main(String[] args) {        try {            ServerSocket serSocket = new ServerSocket(9090);            Socket ser = serSocket.accept();            System.out.println("Connected");            InputStream input = ser.getInputStream();            byte[] data = new byte[100];            int len = input.read();            input.read(data);            String received = new String(data);            System.out.println("Message received: " + received);        } catch (IOException e) {            e.printStackTrace();        }    }}

This method leverages Java’s built-in functions for simplicity and reliability.

Image Transmission Guide

Efficient image transmission involves structuring the data for effective reading and processing.

Image Data Conversion

Convert images into a compressed format, then serialize each pixel’s byte values for transmission:

public void sendImage(OutputStream out, BufferedImage image) {    try {        int[][] imgData = toArray(image);        int imageWidth = imgData.length;        int imageHeight = imgData[0].length;        out.write(imageWidth);        out.write(imageHeight);        for (int i = 0; i < imageWidth; i++) {            for (int j = 0; j < imageHeight; j++) {                byte color = (byte) imgData[i][j];                out.write(color);            }        }    } catch (IOException e) {        e.printStackTrace();    }}

Reading Image Data

The receiver reconstructs the image using the received data:

public class Server {    public static void main(String[] args) {        try {            ServerSocket serSocket = new ServerSocket(9090);            Socket ser = serSocket.accept();            System.out.println("Image transfer initiated");            InputStream input = ser.getInputStream();            int width = input.read();            int height = input.read();            byte[] imgData = new byte[width * height];            int imgBytes = input.read(imgData);            if (imgBytes != width * height) {                throw new IOException("Incomplete image data");            }            // Reconstruct image from imgData        } catch (IOException e) {            e.printStackTrace();        }    }}

Image Transmission Tip: Use Double Buffering

For smooth rendering, use double buffering to ensure the image is drawn without flicker, enhancing user experience.

Summary

These guides provide a robust framework for efficient string and image transmission in Java networking. Tailor the methods to specific requirements to achieve optimal performance and compatibility.

转载地址:http://jjekk.baihongyu.com/

你可能感兴趣的文章
MySQL 内核深度优化
查看>>
mysql 内连接、自然连接、外连接的区别
查看>>
mysql 写入慢优化
查看>>
mysql 分组统计SQL语句
查看>>
Mysql 分页
查看>>
Mysql 分页语句 Limit原理
查看>>
MySql 创建函数 Error Code : 1418
查看>>
MySQL 创建新用户及授予权限的完整流程
查看>>
mysql 创建表,不能包含关键字values 以及 表id自增问题
查看>>
mysql 删除日志文件详解
查看>>
mysql 判断表字段是否存在,然后修改
查看>>
MySQL 到底能不能放到 Docker 里跑?
查看>>
mysql 前缀索引 命令_11 | Mysql怎么给字符串字段加索引?
查看>>
MySQL 加锁处理分析
查看>>
mysql 协议的退出命令包及解析
查看>>
mysql 参数 innodb_flush_log_at_trx_commit
查看>>
mysql 取表中分组之后最新一条数据 分组最新数据 分组取最新数据 分组数据 获取每个分类的最新数据
查看>>
MySQL 命令和内置函数
查看>>
mysql 四种存储引擎
查看>>
MySQL 在并发场景下的问题及解决思路
查看>>