给出android studio登录注册界面的客户端和服务端代码例子

很抱歉，我不能提供完整的客户端和服务端代码，因为这需要考虑到很多因素，例如您的项目需求、数据存储方式等等。但是，我可以给您提供一些参考的例子来帮助您开始编写自己的代码。

客户端代码：

1. 布局文件：login_activity.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">

    <EditText
        android:id="@+id/username_edittext"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="50dp"
        android:hint="Username"
        android:inputType="text"
        android:maxLines="1"
        android:singleLine="true" />

    <EditText
        android:id="@+id/password_edittext"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/username_edittext"
        android:layout_marginTop="20dp"
        android:hint="Password"
        android:inputType="textPassword"
        android:maxLines="1"
        android:singleLine="true" />

    <Button
        android:id="@+id/login_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/password_edittext"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="20dp"
        android:text="Login" />

    <Button
        android:id="@+id/register_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/login_button"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="20dp"
        android:text="Register" />

</RelativeLayout>

2. Java代码：LoginActivity.java

public class LoginActivity extends AppCompatActivity {

    private EditText mUsernameEditText;
    private EditText mPasswordEditText;
    private Button mLoginButton;
    private Button mRegisterButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login_activity);

        mUsernameEditText = findViewById(R.id.username_edittext);
        mPasswordEditText = findViewById(R.id.password_edittext);
        mLoginButton = findViewById(R.id.login_button);
        mRegisterButton = findViewById(R.id.register_button);

        mLoginButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String username = mUsernameEditText.getText().toString();
                String password = mPasswordEditText.getText().toString();
                login(username, password);
            }
        });

        mRegisterButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(LoginActivity.this, RegisterActivity.class);
                startActivity(intent);
            }
        });
    }

    private void login(String username, String password) {
        // 创建HTTP连接
        HttpURLConnection connection = null;
        try {
            URL url = new URL("http://your-server-url.com/login");
            connection = (HttpURLConnection) url.openConnection();

            // 设置请求方法和超时时间
            connection.setRequestMethod("POST");
            connection.setConnectTimeout(5000);

            // 设置请求参数
            String body = "username=" + username + "&password=" + password;
            connection.setDoOutput(true);
            OutputStream outputStream = connection.getOutputStream();
            outputStream.write(body.getBytes());
            outputStream.flush();
            outputStream.close();

            // 解析响应代码和响应数据
            int responseCode = connection.getResponseCode();
            if (responseCode == 200) {
                // 登录成功
                InputStream inputStream = connection.getInputStream();
                String responseData = StreamUtils.inputStreamToString(inputStream);
                JSONObject jsonObject = new JSONObject(responseData);
                String userId = jsonObject.getString("userId");
                String token = jsonObject.getString("token");
                // 存储用户ID和Token
                SharedPreferences sharedPreferences = getSharedPreferences("user_info", MODE_PRIVATE);
                SharedPreferences.Editor editor = sharedPreferences.edit();
                editor.putString("userId", userId);
                editor.putString("token", token);
                editor.apply();
                // 跳转到主界面
                Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                startActivity(intent);
                finish();
            } else {
                // 登录失败
                Toast.makeText(LoginActivity.this, "Login failed", Toast.LENGTH_SHORT).show();
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (connection != null) {
                connection.disconnect();
            }
        }
    }

}

服务端代码：

1. Java代码：LoginServlet.java

public class LoginServlet extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 获取请求参数
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        // 查询数据库，检查用户名和密码是否正确
        User user = UserDao.getUserByUsername(username);
        if (user == null || !user.getPassword().equals(password)) {
            // 用户名或密码不正确，返回401响应代码
            response.setStatus(401);
            return;
        }

        // 生成Token
        String token = TokenUtils.generateToken();

        // 将Token存储到数据库中
        UserDao.updateToken(user.getId(), token);

        // 构造响应JSON数据
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("userId", user.getId());
        jsonObject.put("token", token);

        // 发送响应数据
        response.setContentType("application/json;charset=utf-8");
        PrintWriter out = response.getWriter();
        out.print(jsonObject.toString());
        out.flush();
        out.close();
    }

}

2. Java代码：UserDao.java

public class UserDao {

    public static User getUserByUsername(String username) {
        // 查询数据库，根据用户名获取用户信息
        // ...
        return user;
    }

    public static void updateToken(int userId, String token) {
        // 更新数据库，将Token存储到用户表中
        // ...
    }

}

3. Java代码：TokenUtils.java

public class TokenUtils {

    public static String generateToken() {
        // 生成Token的逻辑
        // ...
        return token;
    }

}

以上代码仅供参考，您需要根据自己的实际需求进行修改和完善。