个人作业Android学习系统开发日志二

实现Android前端搭建：
entity：

package com.example.learningmanagement.entity

data class User(
    val userId: String,
    val username: String,
    val phoneNumber: String,
    val userClass: String,
    val password: String
) {
    // 校验所有字段非空
    private fun validateNotEmpty(): Boolean {
        return userId.isNotEmpty() &&
                username.isNotEmpty() &&
                phoneNumber.isNotEmpty() &&
                userClass.isNotEmpty() &&
                password.isNotEmpty()
    }

    // 校验手机号格式（简单版）
    private fun validatePhoneFormat(): Boolean {
        return phoneNumber.matches(Regex("^1[3-9]\\d{9}$"))
    }

    // 综合校验
    fun validateAll(): String? {
        return when {
            !validateNotEmpty() -> "所有字段不能为空"
            !validatePhoneFormat() -> "手机号格式不正确"
            password.length < 6 -> "密码至少需要6位"
            else -> null // 返回null表示校验通过
        }
    }
}

package com.example.learningmanagement.entity

data class ApiResponse<T>(
    val code: String,
    val msg: String,
    val data: T?
)

network:

package com.example.learningmanagement.network

import com.google.gson.GsonBuilder
import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory

object ServiceCreater {
    val gson = GsonBuilder().setLenient().create()
    //    换网修改IP地址
    private const val BASE_URL="http://192.168.78.220:9090/"
    private val retrofit=Retrofit.Builder()
        .baseUrl(BASE_URL)
        .addConverterFactory(GsonConverterFactory.create(gson))
        .build()
    fun <T> create(serviceClass: Class<T>): T= retrofit.create(serviceClass)
    inline fun<reified T> create(): T= create(T::class.java)
}

service:

package com.example.learningmanagement.service

import com.example.learningmanagement.entity.ApiResponse
import com.example.learningmanagement.entity.User
import retrofit2.http.Body
import retrofit2.http.GET
import retrofit2.http.POST
import retrofit2.http.Query

interface UserApiService {
    @POST("user/register")
    suspend fun register(@Body user: User): ApiResponse<String>

    @POST("user/login")
    suspend fun login(@Body user: User): ApiResponse<User>
}

utils:
实现记住用户名：

package com.example.learningmanagement.utils

import android.content.Context
import android.content.SharedPreferences
import androidx.core.content.edit

class PrefsHelper(context: Context) {
    private val sharedPref: SharedPreferences = 
        context.getSharedPreferences("AppPrefs", Context.MODE_PRIVATE)

    // 存储用户Name
    fun saveLastUserName(username: String) {
        sharedPref.edit() { putString("LAST_USER_NAME", username) }
    }

    // 获取最后登录的用户Name
    fun getLastUserName(): String? {
        return sharedPref.getString("LAST_USER_NAME", null)
    }

    // 清除存储的Name（可选）
    fun clearLastUserName() {
        sharedPref.edit() { remove("LAST_USER_NAME") }
    }
}

activity：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">

    <EditText
        android:id="@+id/etUsername"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="姓名"
        android:inputType="text"/>

    <EditText
        android:id="@+id/etPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="密码"
        android:inputType="textPassword"
        android:layout_marginTop="8dp"/>

    <Button
        android:id="@+id/btnLogin"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="登录"
        android:layout_marginTop="16dp"/>

    <TextView
        android:id="@+id/tvToRegister"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="没有账号？立即注册"
        android:textColor="@color/purple_500"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="16dp"/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">

    <EditText
        android:id="@+id/etUserId"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="学号"
        android:inputType="text"/>

    <EditText
        android:id="@+id/etUsername"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="姓名"
        android:inputType="textPersonName"/>

    <EditText
        android:id="@+id/etPhone"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="手机号"
        android:inputType="phone"/>

    <EditText
        android:id="@+id/etClass"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="班级"
        android:inputType="text"/>

    <EditText
        android:id="@+id/etPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="密码"
        android:inputType="textPassword"/>

    <Button
        android:id="@+id/btnRegister"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="注册"
        android:layout_marginTop="16dp"/>
</LinearLayout>

ui:

package com.example.learningmanagement.ui

import android.annotation.SuppressLint
import android.content.Intent
import android.os.Bundle
import android.widget.Button
import android.widget.EditText
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.lifecycle.lifecycleScope
import com.example.learningmanagement.R
import com.example.learningmanagement.entity.User
import com.example.learningmanagement.network.ServiceCreater
import com.example.learningmanagement.service.UserApiService
import com.example.learningmanagement.utils.PrefsHelper
import kotlinx.coroutines.launch

class LoginActivity : AppCompatActivity() {

    private val prefs by lazy { PrefsHelper(this) }

    private lateinit var etUsername: EditText
    private lateinit var etPassword: EditText
    private lateinit var btnLogin: Button
    private lateinit var tvToRegister: TextView

    private val userService = ServiceCreater.create<UserApiService>()

    @SuppressLint("MissingInflatedId")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_login)

        // 初始化视图
        etUsername = findViewById(R.id.etUsername)
        etPassword = findViewById(R.id.etPassword)
        btnLogin = findViewById(R.id.btnLogin)
        tvToRegister = findViewById(R.id.tvToRegister)

        //记住用户名
        prefs.getLastUserName()?.let { savedName ->
            findViewById<EditText>(R.id.etUsername).setText(savedName)
        }

        // 登录按钮点击事件
        btnLogin.setOnClickListener {
            handleLogin()
        }

        // 跳转到注册页面
        tvToRegister.setOnClickListener {
            startActivity(Intent(this, RegisterActivity::class.java))
        }
    }

    private fun handleLogin() {
        val user = User(
            userId = null.toString(),
            username = etUsername.text.toString().trim(),
            phoneNumber = null.toString(),
            userClass = null.toString(),
            password = etPassword.text.toString().trim()
        )

        if (user.username.isEmpty() || user.password.isEmpty()) {
            Toast.makeText(this, "姓名和密码不能为空", Toast.LENGTH_SHORT).show()
            return
        }

        lifecycleScope.launch {
            try {
                val response = userService.login(user)
                if (response.code == "200") {
                    Toast.makeText(
                        this@LoginActivity,
                        "登录成功",
                        Toast.LENGTH_SHORT
                    ).show()
                    // 这里可以跳转到主页面（例如HomeActivity）
                } else {
                    Toast.makeText(
                        this@LoginActivity,
                        "登录失败: ${response.msg}",
                        Toast.LENGTH_SHORT
                    ).show()
                }
            } catch (e: Exception) {
                Toast.makeText(
                    this@LoginActivity,
                    "网络错误: ${e.message}",
                    Toast.LENGTH_SHORT
                ).show()
            }
        }
    }
}

package com.example.learningmanagement.ui

import android.annotation.SuppressLint
import android.os.Bundle
import android.widget.Button
import android.widget.EditText
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.lifecycle.lifecycleScope
import com.example.learningmanagement.R
import com.example.learningmanagement.entity.User
import com.example.learningmanagement.network.ServiceCreater
import com.example.learningmanagement.service.UserApiService
import com.example.learningmanagement.utils.PrefsHelper
import kotlinx.coroutines.launch

class RegisterActivity : AppCompatActivity() {

    private val prefs by lazy { PrefsHelper(this) }

    private lateinit var etUserId: EditText
    private lateinit var etUsername: EditText
    private lateinit var etPhone: EditText
    private lateinit var etClass: EditText
    private lateinit var etPassword: EditText
    private lateinit var btnRegister: Button

    private val userService = ServiceCreater.create<UserApiService>()

    @SuppressLint("MissingInflatedId")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_register)

        // 初始化视图
        etUserId = findViewById(R.id.etUserId)
        etUsername = findViewById(R.id.etUsername)
        etPhone = findViewById(R.id.etPhone)
        etClass = findViewById(R.id.etClass)
        etPassword = findViewById(R.id.etPassword)
        btnRegister = findViewById(R.id.btnRegister)

        btnRegister.setOnClickListener {
            handleRegister()
        }
    }

    private fun handleRegister() {
        val user = User(
            userId = etUserId.text.toString().trim(),
            username = etUsername.text.toString().trim(),
            phoneNumber = etPhone.text.toString().trim(),
            userClass = etClass.text.toString().trim(),
            password = etPassword.text.toString().trim()
        )

        // 使用实体类的校验方法
        user.validateAll()?.let { errorMsg ->
            Toast.makeText(this, errorMsg, Toast.LENGTH_SHORT).show()
            return
        }

        lifecycleScope.launch {
            try {
                val response = userService.register(user)
                if (response.code == "200") {
                    prefs.saveLastUserName(user.username)
                    Toast.makeText(
                        this@RegisterActivity,
                        response.msg,
                        Toast.LENGTH_SHORT
                    ).show()
                    finish()
                } else {
                    Toast.makeText(
                        this@RegisterActivity,
                        "注册失败: ${response.msg}",
                        Toast.LENGTH_SHORT
                    ).show()
                }
            } catch (e: Exception) {
                Toast.makeText(
                    this@RegisterActivity,
                    "网络错误: ${e.message}",
                    Toast.LENGTH_SHORT
                ).show()
            }
        }
    }
}