Jetpack Compose全局监听用户登录状态自动退出登录

前言

Jetpack Compose一般我们同时也会使用路由进行页面跳转，接口请求的时候，我们想用户信息失效的时候，退出到登录页面，直接在页面监听，就太麻烦和逻辑冗余了。

推荐的做法是

全局状态管理 + 统一网络拦截 + 导航控制

全局状态管理

import androidx.compose.runtime.mutableStateOf

class AuthManager private constructor() {
    val isLoggedIn = mutableStateOf(true)

    fun logout() {
        isLoggedIn.value = false
    }

    fun login() {
        isLoggedIn.value = true
    }

    companion object {
        @Volatile
        private var INSTANCE: AuthManager? = null

        fun getInstance(): AuthManager {
            return INSTANCE ?: synchronized(this) {
                INSTANCE ?: AuthManager().also { INSTANCE = it }
            }
        }
    }
}

网络拦截

接口拦截器中改变状态

import android.os.Handler
import android.os.Looper
import android.util.Log
import com.google.gson.Gson
import com.xhkjedu.zxs_android.common.CommonData
import com.xhkjedu.zxs_android.model.ResultVoNoData
import com.xhkjedu.zxs_android.utils.common.ZSPUtil
import okhttp3.Interceptor
import okhttp3.Response
import okhttp3.ResponseBody
import okhttp3.ResponseBody.Companion.toResponseBody


class HeaderInterceptor : Interceptor {
    val TAG: String = "HeaderInterceptor"

    override fun intercept(chain: Interceptor.Chain): Response {
        val original = chain.request()
        try {
            val mBuilder = original.newBuilder()
            if (CommonData.Authorization != "") {
                mBuilder.header("Authorization", CommonData.Authorization)
            }

            val request = mBuilder
                .method(original.method, original.body)
                .build()

            val response = chain.proceed(request)
            // 获取响应头
            val headers = response.headers
            // 处理响应头
            headers.forEach { header ->
                if (header.first.lowercase() == "authorization") {
                    CommonData.Authorization = header.second
                    ZSPUtil.putString("Authorization", header.second)
                    Handler(Looper.getMainLooper()).post {
                        AuthManager.getInstance().login()
                    }

                }
            }

            return handleResponse(response)
        } catch (_: Exception) {
            return chain.proceed(original)
        }
    }

    /**
     * 响应统一处理
     * @param response 原始响应
     * @return 处理后的响应（可修改响应内容或直接返回原始响应）
     */
    private fun handleResponse(response: Response): Response {
        val statusCode = response.code
        if (statusCode == 200) {
            val body = response.body
            body?.let {
                val contentType = it.contentType()?.toString() ?: ""
                if (contentType.contains("application/json")) {
                    val responseStr = it.string()
                    try {
                        val resultVoNoData =
                            Gson().fromJson(
                                responseStr,
                                ResultVoNoData::class.java
                            )
                        if (resultVoNoData.code == 2) {
                            Handler(Looper.getMainLooper()).post {
                                AuthManager.getInstance().logout()
                            }
                        }
                    } catch (_: Exception) {
                        Log.e(TAG, "handleResponse: 解析失败")
                    }
                    val newBody: ResponseBody = responseStr
                        .toResponseBody(it.contentType())
                    return response.newBuilder().body(newBody).build()
                }
            }

        }
        return response
    }
}

设置拦截器

if (!::commonRetrofit.isInitialized) {
    val client = getUnsafeOkHttpClient().newBuilder()
    .connectTimeout(10, TimeUnit.SECONDS)
    .readTimeout(20, TimeUnit.SECONDS)
    .writeTimeout(20, TimeUnit.SECONDS)
    .addInterceptor(HeaderInterceptor())
    .build();

    commonRetrofit = Retrofit.Builder()
    .baseUrl(ConfigData.apiUrl)
    .client(client)
    .addConverterFactory(GsonConverterFactory.create())
    .build()
}

导航控制

路由配置中监听登录状态变化，退出登录。

通过监听状态，只有状态变化的时候才会退出登录，防止多次触发。

@Composable
fun AppNavigation() {
    val navController = rememberNavController()

    val authManager = AuthManager.getInstance()
    val isLoggedIn by authManager.isLoggedIn
    // 如果状态变为未登录，强制跳转到登录页
    LaunchedEffect(isLoggedIn) {
        if (!isLoggedIn) {
            navController.navigate(AppScreen.ScreenLogin.route) {
                popUpTo(navController.graph.startDestinationId) { inclusive = true }
                launchSingleTop = true
            }
        }
    }

    CompositionLocalProvider(LocalNavController provides navController) {
        NavHost(
            navController = navController,
            startDestination = "root",
            // 添加共享元素动画
            enterTransition = {
                slideIntoContainer(
                    AnimatedContentTransitionScope.SlideDirection.Left
                )
            },
            exitTransition = {
                slideOutOfContainer(
                    AnimatedContentTransitionScope.SlideDirection.Right
                )
            }
        ) {
            rootNavGraph(navController)
        }
    }
}

核心代码

val authManager = AuthManager.getInstance()
val isLoggedIn by authManager.isLoggedIn
// 如果状态变为未登录，强制跳转到登录页
LaunchedEffect(isLoggedIn) {
    if (!isLoggedIn) {
        navController.navigate(AppScreen.ScreenLogin.route) {
            popUpTo(navController.graph.startDestinationId) { inclusive = true }
            launchSingleTop = true
        }
    }
}