Java聊天室之使用Socket实现传递图片

一、题目描述

题目实现：使用网络编程时，需要通过Socket传递图片。

二、解题思路

创建一个服务器类：ServerSocketFrame，继承JFrame类

写一个getserver() 方法，实例化Socket对象，启用9527当服务的端口。

创建输入流对象，用来接收客户端信息。

再定义一个getClientInfo()方法，用于接收客户端发送的信息。

对文本框添加一个事件：实现向客户端发磅信息。

创建一个客户端类：ClientSocketFrame，继承JFrame类。

写一个connect() 方法，实例化Socket对象，连接本地服务的9527端口服务。

再定义一个getClientInfo()方法，用于接收服务端发送的信息。

技术重点：

通过使用DataInputStream类的read0方法，将图片文件读取到字节数组，然后使用 DataOutputStream类从DataOutput类继承的write0方法输出字节数组，从而实现了使用Socket传输图片的功能。

三、代码详解

ServerSocketFrame

 
package com.xiaoxuzhu;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;
import java.net.*;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.BevelBorder;
import javax.swing.border.EtchedBorder;
import javax.swing.filechooser.FileFilter;
import javax.swing.filechooser.FileNameExtensionFilter;
/**
 * Description: 
 *
 * @author xiaoxuzhu
 * @version 1.0
 *
 * <pre>
 * 修改记录:
 * 修改后版本	        修改人		修改日期			修改内容
 * 2022/6/4.1	    xiaoxuzhu		2022/6/4		    Create
 * </pre>
 * @date 2022/6/4
 */
 
public class ServerSocketFrame extends JFrame {
    private Image sendImg = null; // 声明图像对象
    private Image receiveImg = null; // 声明图像对象
    private SendImagePanel sendImagePanel = null; // 声明图像面板对象
    private ReceiveImagePanel receiveImagePanel = null; // 声明图像面板对象
    private File imgFile = null;// 声明所选择图片的File对象
    private JTextField tf_path;
    private DataOutputStream out = null; // 创建流对象
    private DataInputStream in = null; // 创建流对象
    private ServerSocket server; // 声明ServerSocket对象
    private Socket socket; // 声明Socket对象socket
    private long lengths = -1; // 图片文件的大小
    public void getServer() {
        try {
            server = new ServerSocket(9527); // 实例化Socket对象
            while (true) { // 如果套接字是连接状态
                socket = server.accept(); // 实例化Socket对象
                out = new DataOutputStream(socket.getOutputStream());// 获得输出流对象
                in = new DataInputStream(socket.getInputStream());// 获得输入流对象
                getClientInfo(); // 调用getClientInfo()方法
            }
        } catch (Exception e) {
            e.printStackTrace(); // 输出异常信息
        }
    }
 
    private void getClientInfo() {
        try {
            long lengths = in.readLong();// 读取图片文件的长度
            byte[] bt = new byte[(int) lengths];// 创建字节数组
            for (int i = 0; i < bt.length; i++) {
                bt[i] = in.readByte();// 读取字节信息并存储到字节数组
            }
            receiveImg = new ImageIcon(bt).getImage();// 创建图像对象
            receiveImagePanel.repaint();// 重新绘制图像
        } catch (Exception e) {
        } finally {
            try {
                if (in != null) {
                    in.close();// 关闭流
                }
                if (socket != null) {
                    socket.close(); // 关闭套接字
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
 
    public static void main(String[] args) { // 主方法
        ServerSocketFrame frame = new ServerSocketFrame(); // 创建本类对象
        frame.setVisible(true);
        frame.getServer(); // 调用方法
    }
 
    public ServerSocketFrame() {
        super();
        setTitle("服务器端程序");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 379, 260);
 
        final JPanel panel = new JPanel();
        getContentPane().add(panel, BorderLayout.NORTH);
 
        final JLabel label = new JLabel();
        label.setText("路径：");
        panel.add(label);
 
        tf_path = new JTextField();
        tf_path.setPreferredSize(new Dimension(140, 25));
        panel.add(tf_path);
 
        sendImagePanel = new SendImagePanel();
        receiveImagePanel = new ReceiveImagePanel();
        final JButton button_1 = new JButton();
        button_1.addActionListener(new ActionListener() {
            public void actionPerformed(final ActionEvent e) {
                JFileChooser fileChooser = new JFileChooser();// 创建文件选择器
                FileFilter filter = new FileNameExtensionFilter(
                        "图像文件（JPG/GIF/BMP)", "JPG", "JPEG", "GIF", "BMP");// 创建过滤器
                fileChooser.setFileFilter(filter);// 设置过滤器
                int flag = fileChooser.showOpenDialog(null);// 显示打开对话框
                if (flag == JFileChooser.APPROVE_OPTION) {
                    imgFile = fileChooser.getSelectedFile(); // 获取选中图片的File对象
                }
                if (imgFile != null) {
                    tf_path.setText(imgFile.getAbsolutePath());// 图片完整路径
                    try {
                        sendImg = ImageIO.read(imgFile);// 构造BufferedImage对象
                    } catch (IOException ex) {
                        ex.printStackTrace();
                    }
                }
                sendImagePanel.repaint();// 调用paint()方法
            }
        });
        button_1.setText("选择图片");
        panel.add(button_1);
 
        final JButton button = new JButton();
        button.addActionListener(new ActionListener() {
            public void actionPerformed(final ActionEvent e) {
                try {
                    DataInputStream inStream = null;// 定义数据输入流对象
                    if (imgFile != null) {
                        lengths = imgFile.length();// 获得选择图片的大小
                        inStream = new DataInputStream(new FileInputStream(imgFile));// 创建输入流对象
                    } else {
                        JOptionPane.showMessageDialog(null, "还没有选择图片文件。");
                        return;
                    }
                    out.writeLong(lengths);// 将文件的大小写入输出流
                    byte[] bt = new byte[(int) lengths];// 创建字节数组
                    int len = -1;
                    while ((len = inStream.read(bt)) != -1) {// 将图片文件读取到字节数组
                        out.write(bt);// 将字节数组写入输出流
                    }
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        });
        button.setText("发  送");
        panel.add(button);
 
        final JPanel panel_1 = new JPanel();
        panel_1.setLayout(new BorderLayout());
        getContentPane().add(panel_1, BorderLayout.CENTER);
 
        final JPanel panel_2 = new JPanel();
        panel_2.setLayout(new GridLayout(1, 0));
        final FlowLayout flowLayout = new FlowLayout();
        flowLayout.setAlignment(FlowLayout.LEFT);
        panel_2.setLayout(flowLayout);
        panel_1.add(panel_2, BorderLayout.NORTH);
 
        final JLabel label_1 = new JLabel();
        label_1.setBorder(new EtchedBorder(EtchedBorder.LOWERED));
        label_1.setText("服务器端选择的要发送的图片  ");
        panel_2.add(label_1);
 
        final JLabel label_2 = new JLabel();
        label_2.setBorder(new EtchedBorder(EtchedBorder.LOWERED));
        label_2.setText("接收到客户端发送的图片       ");
        panel_2.add(label_2);
 
        final JPanel imgPanel = new JPanel();
        final GridLayout gridLayout = new GridLayout(1, 0);
        gridLayout.setVgap(10);
        imgPanel.setLayout(gridLayout);
        panel_1.add(imgPanel, BorderLayout.CENTER);
        imgPanel.add(sendImagePanel);
        imgPanel.add(receiveImagePanel);
        sendImagePanel.setBorder(new BevelBorder(BevelBorder.LOWERED));
        receiveImagePanel.setBorder(new BevelBorder(BevelBorder.LOWERED));
    }
 
    // 创建面板类
    class SendImagePanel extends JPanel {
        public void paint(Graphics g) {
            if (sendImg != null) {
                g.clearRect(0, 0, this.getWidth(), this.getHeight());// 清除绘图上下文的内容
                g.drawImage(sendImg, 0, 0, this.getWidth(), this.getHeight(),
                        this);// 绘制指定大小的图片
            }
        }
    }
 
    // 创建面板类
    class ReceiveImagePanel extends JPanel {
        public void paint(Graphics g) {
            if (receiveImg != null) {
                g.clearRect(0, 0, this.getWidth(), this.getHeight());// 清除绘图上下文的内容
                g.drawImage(receiveImg, 0, 0, this.getWidth(),
                        this.getHeight(), this);// 绘制指定大小的图片
            }
        }
    }
}

ClientSocketFrame

 
package com.xiaoxuzhu;
 
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.Socket;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.ImageIcon;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EtchedBorder;
import javax.swing.filechooser.FileFilter;
import javax.swing.filechooser.FileNameExtensionFilter;
 
/**
 * Description: 
 *
 * @author xiaoxuzhu
 * @version 1.0
 *
 * <pre>
 * 修改记录:
 * 修改后版本	        修改人		修改日期			修改内容
 * 2022/6/4.1	    xiaoxuzhu		2022/6/4		    Create
 * </pre>
 * @date 2022/6/4
 */
 
public class ClientSocketFrame extends JFrame {
    private Image sendImg = null; // 声明图像对象
    private Image receiveImg = null; // 声明图像对象
    private SendImagePanel sendImagePanel = null; // 声明图像面板对象
    private ReceiveImagePanel receiveImagePanel = null; // 声明图像面板对象
    private File imgFile = null;// 声明所选择图片的File对象
    private JTextField tf_path;
    private DataInputStream in = null; // 创建流对象
    private DataOutputStream out = null; // 创建流对象
    private Socket socket; // 声明Socket对象
    private Container cc; // 声明Container对象
    private long lengths = -1;// 图片文件的大小
 
    private void connect() { // 连接套接字方法
        try { // 捕捉异常
            socket = new Socket("127.0.0.1", 9527); // 实例化Socket对象
            while (true) {
                if (socket != null && !socket.isClosed()) {
                    out = new DataOutputStream(socket.getOutputStream());// 获得输出流对象
                    in = new DataInputStream(socket.getInputStream());// 获得输入流对象
                    getServerInfo();// 调用getServerInfo()方法
                } else {
                    socket = new Socket("127.0.0.1", 9527); // 实例化Socket对象
                }
            }
        } catch (Exception e) {
            e.printStackTrace(); // 输出异常信息
        }
    }
 
    public static void main(String[] args) { // 主方法
        ClientSocketFrame clien = new ClientSocketFrame(); // 创建本例对象
        clien.setVisible(true); // 将窗体显示
        clien.connect(); // 调用连接方法
    }
 
    private void getServerInfo() {
        try {
            long lengths = in.readLong();// 读取图片文件的长度
            byte[] bt = new byte[(int) lengths];// 创建字节数组
            for (int i = 0; i < bt.length; i++) {
                bt[i] = in.readByte();// 读取字节信息并存储到字节数组
            }
            receiveImg = new ImageIcon(bt).getImage();// 创建图像对象
            receiveImagePanel.repaint();// 重新绘制图像
        } catch (Exception e) {
        } finally {
            try {
                if (in != null) {
                    in.close();// 关闭流
                }
                if (socket != null) {
                    socket.close(); // 关闭套接字
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
 
    /**
     * Create the frame
     */
    public ClientSocketFrame() {
        super();
        setTitle("客户端程序");
        setBounds(100, 100, 373, 257);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
        final JPanel panel = new JPanel();
        getContentPane().add(panel, BorderLayout.NORTH);
 
        final JLabel label = new JLabel();
        label.setText("路径：");
        panel.add(label);
 
        tf_path = new JTextField();
        tf_path.setPreferredSize(new Dimension(140, 25));
        panel.add(tf_path);
 
        final JButton button = new JButton();
        button.addActionListener(new ActionListener() {
            public void actionPerformed(final ActionEvent e) {
                JFileChooser fileChooser = new JFileChooser();// 创建文件选择器
                FileFilter filter = new FileNameExtensionFilter(
                        "图像文件（JPG/GIF/BMP)", "JPG", "JPEG", "GIF", "BMP");// 创建过滤器
                fileChooser.setFileFilter(filter);// 设置过滤器
                int flag = fileChooser.showOpenDialog(null);// 显示打开对话框
                if (flag == JFileChooser.APPROVE_OPTION) {
                    imgFile = fileChooser.getSelectedFile(); // 获取选中图片的File对象
                }
                if (imgFile != null) {
                    tf_path.setText(imgFile.getAbsolutePath());// 图片完整路径
                    try {
                        sendImg = ImageIO.read(imgFile);// 构造BufferedImage对象
                    } catch (IOException ex) {
                        ex.printStackTrace();
                    }
                }
                sendImagePanel.repaint();// 调用paint()方法
            }
        });
        button.setText("选择图片");
        panel.add(button);
 
        final JButton button_1 = new JButton();
        button_1.addActionListener(new ActionListener() {
            public void actionPerformed(final ActionEvent e) {
                try {
                    DataInputStream inStream = null;// 定义数据输入流对象
                    if (imgFile != null) {
                        lengths = imgFile.length();// 获得选择图片的大小
                        inStream = new DataInputStream(new FileInputStream(
                                imgFile));// 创建输入流对象
                    } else {
                        JOptionPane.showMessageDialog(null, "还没有选择图片文件。");
                        return;
                    }
                    out.writeLong(lengths);// 将文件的大小写入输出流
                    byte[] bt = new byte[(int) lengths];// 创建字节数组
                    int len = -1;
                    while ((len = inStream.read(bt)) != -1) {// 将图片文件读取到字节数组
                        out.write(bt);// 将字节数组写入输出流
                    }
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        });
        button_1.setText("发  送");
        panel.add(button_1);
 
        final JPanel panel_1 = new JPanel();
        panel_1.setLayout(new BorderLayout());
        getContentPane().add(panel_1, BorderLayout.CENTER);
 
        final JPanel panel_2 = new JPanel();
        panel_2.setLayout(new GridLayout(1, 0));
        panel_1.add(panel_2, BorderLayout.NORTH);
 
        final JLabel label_1 = new JLabel();
        label_1.setBorder(new EtchedBorder(EtchedBorder.LOWERED));
        label_1.setText("客户端选择的要发送的图片");
        panel_2.add(label_1);
 
        final JLabel label_2 = new JLabel();
        label_2.setBorder(new EtchedBorder(EtchedBorder.LOWERED));
        label_2.setText("接收到服务器端发送的图片     ");
        panel_2.add(label_2);
 
        final JPanel imgPanel = new JPanel();
        sendImagePanel = new SendImagePanel();
        receiveImagePanel = new ReceiveImagePanel();
        imgPanel.add(sendImagePanel);
        imgPanel.add(receiveImagePanel);
        final GridLayout gridLayout = new GridLayout(1, 0);
        gridLayout.setVgap(6);
        imgPanel.setLayout(gridLayout);
        panel_1.add(imgPanel, BorderLayout.CENTER);
        //
    }
 
    // 创建面板类
    class SendImagePanel extends JPanel {
        public void paint(Graphics g) {
            if (sendImg != null) {
                g.clearRect(0, 0, this.getWidth(), this.getHeight());// 清除绘图上下文的内容
                g.drawImage(sendImg, 0, 0, this.getWidth(), this.getHeight(),
                        this);// 绘制指定大小的图片
            }
        }
    }
 
    // 创建面板类
    class ReceiveImagePanel extends JPanel {
        public void paint(Graphics g) {
            if (receiveImg != null) {
                g.clearRect(0, 0, this.getWidth(), this.getHeight());// 清除绘图上下文的内容
                g.drawImage(receiveImg, 0, 0, this.getWidth(),
                        this.getHeight(), this);// 绘制指定大小的图片
            }
        }
    }
}

服务器启动

客户端启动

	package com.xiaoxuzhu;
	import java.awt.BorderLayout;
	import java.awt.Dimension;
	import java.awt.FlowLayout;
	import java.awt.Graphics;
	import java.awt.GridLayout;
	import java.awt.Image;
	import java.awt.event.ActionEvent;
	import java.awt.event.ActionListener;
	import java.io.*;
	import java.net.*;
	import javax.imageio.ImageIO;
	import javax.swing.ImageIcon;
	import javax.swing.JButton;
	import javax.swing.JFileChooser;
	import javax.swing.JFrame;
	import javax.swing.JLabel;
	import javax.swing.JOptionPane;
	import javax.swing.JPanel;
	import javax.swing.JTextField;
	import javax.swing.border.BevelBorder;
	import javax.swing.border.EtchedBorder;
	import javax.swing.filechooser.FileFilter;
	import javax.swing.filechooser.FileNameExtensionFilter;
	/**
	* Description:
	*
	* @author xiaoxuzhu
	* @version 1.0
	*
	* <pre>
	* 修改记录:
	* 修改后版本修改人修改日期修改内容
	* 2022/6/4.1 xiaoxuzhu 2022/6/4 Create
	* </pre>
	* @date 2022/6/4
	*/

	public class ServerSocketFrame extends JFrame {
	private Image sendImg = null; // 声明图像对象
	private Image receiveImg = null; // 声明图像对象
	private SendImagePanel sendImagePanel = null; // 声明图像面板对象
	private ReceiveImagePanel receiveImagePanel = null; // 声明图像面板对象
	private File imgFile = null;// 声明所选择图片的File对象
	private JTextField tf_path;
	private DataOutputStream out = null; // 创建流对象
	private DataInputStream in = null; // 创建流对象
	private ServerSocket server; // 声明ServerSocket对象
	private Socket socket; // 声明Socket对象socket
	private long lengths = -1; // 图片文件的大小
	public void getServer() {
	try {
	server = new ServerSocket(9527); // 实例化Socket对象
	while (true) { // 如果套接字是连接状态
	socket = server.accept(); // 实例化Socket对象
	out = new DataOutputStream(socket.getOutputStream());// 获得输出流对象
	in = new DataInputStream(socket.getInputStream());// 获得输入流对象
	getClientInfo(); // 调用getClientInfo()方法
	}
	} catch (Exception e) {
	e.printStackTrace(); // 输出异常信息
	}
	}

	private void getClientInfo() {
	try {
	long lengths = in.readLong();// 读取图片文件的长度
	byte[] bt = new byte[(int) lengths];// 创建字节数组
	for (int i = 0; i < bt.length; i++) {
	bt[i] = in.readByte();// 读取字节信息并存储到字节数组
	}
	receiveImg = new ImageIcon(bt).getImage();// 创建图像对象
	receiveImagePanel.repaint();// 重新绘制图像
	} catch (Exception e) {
	} finally {
	try {
	if (in != null) {
	in.close();// 关闭流
	}
	if (socket != null) {
	socket.close(); // 关闭套接字
	}
	} catch (IOException e) {
	e.printStackTrace();
	}
	}
	}

	public static void main(String[] args) { // 主方法
	ServerSocketFrame frame = new ServerSocketFrame(); // 创建本类对象
	frame.setVisible(true);
	frame.getServer(); // 调用方法
	}

	public ServerSocketFrame() {
	super();
	setTitle("服务器端程序");
	setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	setBounds(100, 100, 379, 260);

	final JPanel panel = new JPanel();
	getContentPane().add(panel, BorderLayout.NORTH);

	final JLabel label = new JLabel();
	label.setText("路径：");
	panel.add(label);

	tf_path = new JTextField();
	tf_path.setPreferredSize(new Dimension(140, 25));
	panel.add(tf_path);

	sendImagePanel = new SendImagePanel();
	receiveImagePanel = new ReceiveImagePanel();
	final JButton button_1 = new JButton();
	button_1.addActionListener(new ActionListener() {
	public void actionPerformed(final ActionEvent e) {
	JFileChooser fileChooser = new JFileChooser();// 创建文件选择器
	FileFilter filter = new FileNameExtensionFilter(
	"图像文件（JPG/GIF/BMP)", "JPG", "JPEG", "GIF", "BMP");// 创建过滤器
	fileChooser.setFileFilter(filter);// 设置过滤器
	int flag = fileChooser.showOpenDialog(null);// 显示打开对话框
	if (flag == JFileChooser.APPROVE_OPTION) {
	imgFile = fileChooser.getSelectedFile(); // 获取选中图片的File对象
	}
	if (imgFile != null) {
	tf_path.setText(imgFile.getAbsolutePath());// 图片完整路径
	try {
	sendImg = ImageIO.read(imgFile);// 构造BufferedImage对象
	} catch (IOException ex) {
	ex.printStackTrace();
	}
	}
	sendImagePanel.repaint();// 调用paint()方法
	}
	});
	button_1.setText("选择图片");
	panel.add(button_1);

	final JButton button = new JButton();
	button.addActionListener(new ActionListener() {
	public void actionPerformed(final ActionEvent e) {
	try {
	DataInputStream inStream = null;// 定义数据输入流对象
	if (imgFile != null) {
	lengths = imgFile.length();// 获得选择图片的大小
	inStream = new DataInputStream(new FileInputStream(imgFile));// 创建输入流对象
	} else {
	JOptionPane.showMessageDialog(null, "还没有选择图片文件。");
	return;
	}
	out.writeLong(lengths);// 将文件的大小写入输出流
	byte[] bt = new byte[(int) lengths];// 创建字节数组
	int len = -1;
	while ((len = inStream.read(bt)) != -1) {// 将图片文件读取到字节数组
	out.write(bt);// 将字节数组写入输出流
	}
	} catch (IOException e1) {
	e1.printStackTrace();
	}
	}
	});
	button.setText("发送");
	panel.add(button);

	final JPanel panel_1 = new JPanel();
	panel_1.setLayout(new BorderLayout());
	getContentPane().add(panel_1, BorderLayout.CENTER);

	final JPanel panel_2 = new JPanel();
	panel_2.setLayout(new GridLayout(1, 0));
	final FlowLayout flowLayout = new FlowLayout();
	flowLayout.setAlignment(FlowLayout.LEFT);
	panel_2.setLayout(flowLayout);
	panel_1.add(panel_2, BorderLayout.NORTH);

	final JLabel label_1 = new JLabel();
	label_1.setBorder(new EtchedBorder(EtchedBorder.LOWERED));
	label_1.setText("服务器端选择的要发送的图片 ");
	panel_2.add(label_1);

	final JLabel label_2 = new JLabel();
	label_2.setBorder(new EtchedBorder(EtchedBorder.LOWERED));
	label_2.setText("接收到客户端发送的图片 ");
	panel_2.add(label_2);

	final JPanel imgPanel = new JPanel();
	final GridLayout gridLayout = new GridLayout(1, 0);
	gridLayout.setVgap(10);
	imgPanel.setLayout(gridLayout);
	panel_1.add(imgPanel, BorderLayout.CENTER);
	imgPanel.add(sendImagePanel);
	imgPanel.add(receiveImagePanel);
	sendImagePanel.setBorder(new BevelBorder(BevelBorder.LOWERED));
	receiveImagePanel.setBorder(new BevelBorder(BevelBorder.LOWERED));
	}

	// 创建面板类
	class SendImagePanel extends JPanel {
	public void paint(Graphics g) {
	if (sendImg != null) {
	g.clearRect(0, 0, this.getWidth(), this.getHeight());// 清除绘图上下文的内容
	g.drawImage(sendImg, 0, 0, this.getWidth(), this.getHeight(),
	this);// 绘制指定大小的图片
	}
	}
	}

	// 创建面板类
	class ReceiveImagePanel extends JPanel {
	public void paint(Graphics g) {
	if (receiveImg != null) {
	g.clearRect(0, 0, this.getWidth(), this.getHeight());// 清除绘图上下文的内容
	g.drawImage(receiveImg, 0, 0, this.getWidth(),
	this.getHeight(), this);// 绘制指定大小的图片
	}
	}
	}
	}

	package com.xiaoxuzhu;

	import java.awt.BorderLayout;
	import java.awt.Container;
	import java.awt.Dimension;
	import java.awt.Graphics;
	import java.awt.GridLayout;
	import java.awt.Image;
	import java.awt.event.ActionEvent;
	import java.awt.event.ActionListener;
	import java.io.DataInputStream;
	import java.io.DataOutputStream;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.IOException;
	import java.net.Socket;
	import javax.imageio.ImageIO;
	import javax.swing.JButton;
	import javax.swing.ImageIcon;
	import javax.swing.JFileChooser;
	import javax.swing.JFrame;
	import javax.swing.JLabel;
	import javax.swing.JOptionPane;
	import javax.swing.JPanel;
	import javax.swing.JTextField;
	import javax.swing.border.EtchedBorder;
	import javax.swing.filechooser.FileFilter;
	import javax.swing.filechooser.FileNameExtensionFilter;

	/**
	* Description:
	*
	* @author xiaoxuzhu
	* @version 1.0
	*
	* <pre>
	* 修改记录:
	* 修改后版本修改人修改日期修改内容
	* 2022/6/4.1 xiaoxuzhu 2022/6/4 Create
	* </pre>
	* @date 2022/6/4
	*/

	public class ClientSocketFrame extends JFrame {
	private Image sendImg = null; // 声明图像对象
	private Image receiveImg = null; // 声明图像对象
	private SendImagePanel sendImagePanel = null; // 声明图像面板对象
	private ReceiveImagePanel receiveImagePanel = null; // 声明图像面板对象
	private File imgFile = null;// 声明所选择图片的File对象
	private JTextField tf_path;
	private DataInputStream in = null; // 创建流对象
	private DataOutputStream out = null; // 创建流对象
	private Socket socket; // 声明Socket对象
	private Container cc; // 声明Container对象
	private long lengths = -1;// 图片文件的大小

	private void connect() { // 连接套接字方法
	try { // 捕捉异常
	socket = new Socket("127.0.0.1", 9527); // 实例化Socket对象
	while (true) {
	if (socket != null && !socket.isClosed()) {
	out = new DataOutputStream(socket.getOutputStream());// 获得输出流对象
	in = new DataInputStream(socket.getInputStream());// 获得输入流对象
	getServerInfo();// 调用getServerInfo()方法
	} else {
	socket = new Socket("127.0.0.1", 9527); // 实例化Socket对象
	}
	}
	} catch (Exception e) {
	e.printStackTrace(); // 输出异常信息
	}
	}

	public static void main(String[] args) { // 主方法
	ClientSocketFrame clien = new ClientSocketFrame(); // 创建本例对象
	clien.setVisible(true); // 将窗体显示
	clien.connect(); // 调用连接方法
	}

	private void getServerInfo() {
	try {
	long lengths = in.readLong();// 读取图片文件的长度
	byte[] bt = new byte[(int) lengths];// 创建字节数组
	for (int i = 0; i < bt.length; i++) {
	bt[i] = in.readByte();// 读取字节信息并存储到字节数组
	}
	receiveImg = new ImageIcon(bt).getImage();// 创建图像对象
	receiveImagePanel.repaint();// 重新绘制图像
	} catch (Exception e) {
	} finally {
	try {
	if (in != null) {
	in.close();// 关闭流
	}
	if (socket != null) {
	socket.close(); // 关闭套接字
	}
	} catch (IOException e) {
	e.printStackTrace();
	}
	}
	}

	/**
	* Create the frame
	*/
	public ClientSocketFrame() {
	super();
	setTitle("客户端程序");
	setBounds(100, 100, 373, 257);
	setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

	final JPanel panel = new JPanel();
	getContentPane().add(panel, BorderLayout.NORTH);

	final JLabel label = new JLabel();
	label.setText("路径：");
	panel.add(label);

	tf_path = new JTextField();
	tf_path.setPreferredSize(new Dimension(140, 25));
	panel.add(tf_path);

	final JButton button = new JButton();
	button.addActionListener(new ActionListener() {
	public void actionPerformed(final ActionEvent e) {
	JFileChooser fileChooser = new JFileChooser();// 创建文件选择器
	FileFilter filter = new FileNameExtensionFilter(
	"图像文件（JPG/GIF/BMP)", "JPG", "JPEG", "GIF", "BMP");// 创建过滤器
	fileChooser.setFileFilter(filter);// 设置过滤器
	int flag = fileChooser.showOpenDialog(null);// 显示打开对话框
	if (flag == JFileChooser.APPROVE_OPTION) {
	imgFile = fileChooser.getSelectedFile(); // 获取选中图片的File对象
	}
	if (imgFile != null) {
	tf_path.setText(imgFile.getAbsolutePath());// 图片完整路径
	try {
	sendImg = ImageIO.read(imgFile);// 构造BufferedImage对象
	} catch (IOException ex) {
	ex.printStackTrace();
	}
	}
	sendImagePanel.repaint();// 调用paint()方法
	}
	});
	button.setText("选择图片");
	panel.add(button);

	final JButton button_1 = new JButton();
	button_1.addActionListener(new ActionListener() {
	public void actionPerformed(final ActionEvent e) {
	try {
	DataInputStream inStream = null;// 定义数据输入流对象
	if (imgFile != null) {
	lengths = imgFile.length();// 获得选择图片的大小
	inStream = new DataInputStream(new FileInputStream(
	imgFile));// 创建输入流对象
	} else {
	JOptionPane.showMessageDialog(null, "还没有选择图片文件。");
	return;
	}
	out.writeLong(lengths);// 将文件的大小写入输出流
	byte[] bt = new byte[(int) lengths];// 创建字节数组
	int len = -1;
	while ((len = inStream.read(bt)) != -1) {// 将图片文件读取到字节数组
	out.write(bt);// 将字节数组写入输出流
	}
	} catch (IOException e1) {
	e1.printStackTrace();
	}
	}
	});
	button_1.setText("发送");
	panel.add(button_1);

	final JPanel panel_1 = new JPanel();
	panel_1.setLayout(new BorderLayout());
	getContentPane().add(panel_1, BorderLayout.CENTER);

	final JPanel panel_2 = new JPanel();
	panel_2.setLayout(new GridLayout(1, 0));
	panel_1.add(panel_2, BorderLayout.NORTH);

	final JLabel label_1 = new JLabel();
	label_1.setBorder(new EtchedBorder(EtchedBorder.LOWERED));
	label_1.setText("客户端选择的要发送的图片");
	panel_2.add(label_1);

	final JLabel label_2 = new JLabel();
	label_2.setBorder(new EtchedBorder(EtchedBorder.LOWERED));
	label_2.setText("接收到服务器端发送的图片 ");
	panel_2.add(label_2);

	final JPanel imgPanel = new JPanel();
	sendImagePanel = new SendImagePanel();
	receiveImagePanel = new ReceiveImagePanel();
	imgPanel.add(sendImagePanel);
	imgPanel.add(receiveImagePanel);
	final GridLayout gridLayout = new GridLayout(1, 0);
	gridLayout.setVgap(6);
	imgPanel.setLayout(gridLayout);
	panel_1.add(imgPanel, BorderLayout.CENTER);
	//
	}

	// 创建面板类
	class SendImagePanel extends JPanel {
	public void paint(Graphics g) {
	if (sendImg != null) {
	g.clearRect(0, 0, this.getWidth(), this.getHeight());// 清除绘图上下文的内容
	g.drawImage(sendImg, 0, 0, this.getWidth(), this.getHeight(),
	this);// 绘制指定大小的图片
	}
	}
	}

	// 创建面板类
	class ReceiveImagePanel extends JPanel {
	public void paint(Graphics g) {
	if (receiveImg != null) {
	g.clearRect(0, 0, this.getWidth(), this.getHeight());// 清除绘图上下文的内容
	g.drawImage(receiveImg, 0, 0, this.getWidth(),
	this.getHeight(), this);// 绘制指定大小的图片
	}
	}
	}
	}

Java聊天室之使用Socket实现传递图片

目录

一、题目描述

二、解题思路

三、代码详解