更换位置

server/db.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"database/sql"
+	"log"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+var db *sql.DB
+
+func InitDB() {
+	var err error
+	db, err = sql.Open("sqlite3", "./chat.db")
+	if err != nil {
+		log.Fatalf("打开数据库失败: %v", err)
+	}
+
+	createTableSQL := `
+    CREATE TABLE IF NOT EXISTS messages (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        sender TEXT NOT NULL,
+        receiver TEXT NOT NULL,
+        content TEXT NOT NULL,
+        timestamp DATETIME NOT NULL
+    );
+    `
+	_, err = db.Exec(createTableSQL)
+	if err != nil {
+		log.Fatalf("创建表失败: %v", err)
+	}
+}
+
+func SaveMessage(sender, receiver, content string) error {
+	stmt, err := db.Prepare("INSERT INTO messages(sender, receiver, content, timestamp) VALUES (?, ?, ?, ?)")
+	if err != nil {
+		return err
+	}
+	defer stmt.Close()
+
+	_, err = stmt.Exec(sender, receiver, content, time.Now())
+	return err
+}
+
+func GetMessages(sender, receiver string) ([]Message, error) {
+	rows, err := db.Query("SELECT sender, receiver, content, timestamp FROM messages WHERE (sender = ? AND receiver = ?) OR (sender = ? AND receiver = ?) ORDER BY timestamp ASC", sender, receiver, receiver, sender)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var messages []Message
+	for rows.Next() {
+		var msg Message
+		var ts string
+		err = rows.Scan(&msg.Sender, &msg.Receiver, &msg.Content, &ts)
+		if err != nil {
+			return nil, err
+		}
+		msg.Timestamp, _ = time.Parse(time.RFC3339, ts)
+		messages = append(messages, msg)
+	}
+	return messages, nil
+}
+
+type Message struct {
+	Sender    string
+	Receiver  string
+	Content   string
+	Timestamp time.Time
+}

server/file_transfer.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"os"
+)
+
+// 服务器端接收文件的示例函数
+func ReceiveFile(conn net.Conn, filename string, filesize int64) error {
+	file, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	var received int64 = 0
+	buf := make([]byte, 4096)
+	for received < filesize {
+		n, err := conn.Read(buf)
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return err
+		}
+		file.Write(buf[:n])
+		received += int64(n)
+	}
+	fmt.Printf("文件 %s 接收完成，共 %d 字节\n", filename, received)
+	return nil
+}
+
+// 服务器端发送文件的示例函数
+func SendFile(conn net.Conn, filepath string) error {
+	file, err := os.Open(filepath)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	buf := make([]byte, 4096)
+	for {
+		n, err := file.Read(buf)
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return err
+		}
+		_, err = conn.Write(buf[:n])
+		if err != nil {
+			return err
+		}
+	}
+	fmt.Printf("文件 %s 发送完成\n", filepath)
+	return nil
+}

server/main.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"net"
+	"sync"
+)
+
+var (
+	clients   = make(map[net.Conn]string) // 连接映射：连接对象到用户名
+	clientsMu sync.Mutex                  // 保护clients的互斥锁
+)
+
+func main() {
+	listener, err := net.Listen("tcp", ":8888")
+	if err != nil {
+		log.Fatalf("监听端口失败: %v", err)
+	}
+	defer listener.Close()
+	fmt.Println("服务器已启动，监听端口 8888")
+
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			log.Printf("接受连接失败: %v", err)
+			continue
+		}
+		go handleConnection(conn)
+	}
+}
+
+func handleConnection(conn net.Conn) {
+	defer func() {
+		// 连接关闭时，移除客户端
+		clientsMu.Lock()
+		delete(clients, conn)
+		clientsMu.Unlock()
+		conn.Close()
+		broadcast(fmt.Sprintf("用户退出：%s", conn.RemoteAddr().String()), "系统")
+		fmt.Printf("客户端断开：%s\n", conn.RemoteAddr().String())
+	}()
+
+	// 添加新连接
+	clientsMu.Lock()
+	clients[conn] = conn.RemoteAddr().String()
+	clientsMu.Unlock()
+
+	// 通知所有客户端有新用户加入
+	broadcast(fmt.Sprintf("新用户加入：%s", conn.RemoteAddr().String()), "系统")
+
+	scanner := bufio.NewScanner(conn)
+	for scanner.Scan() {
+		msg := scanner.Text()
+		sender := clients[conn]
+		broadcast(msg, sender)
+	}
+	if err := scanner.Err(); err != nil {
+		log.Printf("读取消息错误: %v", err)
+	}
+}
+
+func broadcast(message, sender string) {
+	clientsMu.Lock()
+	defer clientsMu.Unlock()
+	for c := range clients {
+		if c != nil {
+			_, err := fmt.Fprintf(c, "[%s] %s\n", sender, message)
+			if err != nil {
+				log.Printf("广播失败: %v", err)
+			}
+		}
+	}
+}