客户端传输对象

//建立User类

public class User implements Serializable {
     private String userName;
     private String userId;
     public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public String getUserId() {
        return userId;
    }
    public void setUserId(String userId) {
        this.userId = userId;
    }
    public User(){};
     public User(String userName,String userId){
         this.userName=userName;
         this.userId=userId;
     };
}

客户端相关代码

OutputStream os = socket.getOutputStream();// 字节输出流
            PrintWriter pwPrintWriter = new PrintWriter(os);// 将输出流包装成打印流
            ObjectOutputStream oos = new ObjectOutputStream(os);
            // pwPrintWriter.write("用户名：Tom;密码：783");//传入字符串
            User user = new User("Tom", "783");// 传入对象
            oos.writeObject(user);
            pwPrintWriter.flush();
            socket.shutdownOutput();

服务器端相关代码

ObjectInputStream is = new ObjectInputStream(socket.getInputStream());
User user = (User) is.readObject();
System.out.println("我是服务器，客户端说" + user.getUserName() + ":"
        + user.getUserId());
socket.shutdownInput();// 关闭输入流
outputStream = socket.getOutputStream(); 

服务器端传输文件，建立File文件夹，里面放置File/UDPClient.txt文件

            file = new File("File/UDPClient.txt");
            fin = new FileInputStream(file);
            byte[] sendByte = new byte[1024];       
            ObjectOutputStream obj=new ObjectOutputStream(outputStream);
            int length;
            while ((length = fin.read(sendByte, 0, sendByte.length))!=-1) {
                obj.write(sendByte, 0, length);
                obj.flush();
            }

客户端接收文件，并进行写出文件

            ObjectInputStream din =new ObjectInputStream(inputStream);      
            FileOutputStream fos = new FileOutputStream("File/UDOClient1.txt"); 
            byte[] buf=new byte[1024];
            int len;
            while ((len = din.read(buf,0,buf.length)) != -1) {
                fos.write(buf, 0, len);
                fos.flush();
            }
            fos.close();
            socket.shutdownInput();