Retrofit2拦截器设置及响应无法拦截的问题

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Retrofit2拦截器设置及响应无法拦截的问题

前言

我们在添加响应切面后原接口无法接收响应的问题，核心原因是

OkHttp 的 ResponseBody 是一次性流（仅能读取一次）

也就是说代码中调用了 body.string() 读取响应体，导致流被耗尽，后续 Retrofit 解析响应时，流已无数据可读，最终接口无法获取结果。

这里的解决方法是

重新构建 ResponseBody

拦截器

完整代码

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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.SPUtil
import com.xhkjedu.zxs_android.utils.eventbus.ZEventExitLogin
import com.xhkjedu.zxs_android.utils.eventbus.ZFlowEventBus
import kotlinx.coroutines.CoroutineName
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.Job
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking
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 == "Authorization") {
                    CommonData.Authorization = header.second
                    SPUtil.putString("Authorization", header.second)
                }
            }

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

    class InterceptorCoroutineScope : CoroutineScope {
        // 核心：通过Job控制作用域生命周期，取消Job则作用域内所有协程终止
        private val job = Job()

        // 配置协程调度器（根据需求选择，如IO调度器处理网络/本地存储）
        override val coroutineContext = Dispatchers.IO + job + CoroutineName("InterceptorScope")

        // 取消作用域（拦截器结束时调用）
        fun cancelScope() {
            job.cancel()
        }
    }

    /**
     * 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) {
                            // 创建临时协程作用域（拦截器执行完后会取消）
                            val scope = InterceptorCoroutineScope()
                            try {
                                runBlocking(scope.coroutineContext) {
                                    launch {
                                        ZFlowEventBus.post(ZEventExitLogin())
                                    }
                                }
                            } finally {
                                scope.cancelScope()
                            }
                        }
                    } 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
    }
}

响应处理

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/**
     * 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
        if (body != null) {
            val responseStr = body.string()
            // 下面可以写自定义响应处理的逻辑

            // 重建ResponseBody
            val newBody: ResponseBody? = responseStr
            .toResponseBody(it.contentType())
            return response.newBuilder().body(newBody).build()
        }
    }
    return response
}

自定义协程

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class InterceptorCoroutineScope : CoroutineScope {
    // 核心：通过Job控制作用域生命周期，取消Job则作用域内所有协程终止
    private val job = Job()

    // 配置协程调度器（根据需求选择，如IO调度器处理网络/本地存储）
    override val coroutineContext = Dispatchers.IO + job + CoroutineName("InterceptorScope")

    // 取消作用域（拦截器结束时调用）
    fun cancelScope() {
        job.cancel()
    }
}

协程使用

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// 创建临时协程作用域（拦截器执行完后会取消）
val scope = InterceptorCoroutineScope()
try {
    runBlocking(scope.coroutineContext) {
        launch {
            ZFlowEventBus.post(ZEventExitLogin())
        }
    }
} finally {
    scope.cancelScope()
}

设置拦截器

完整代码

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import android.annotation.SuppressLint
import com.xhkjedu.zxs_android.common.CommonData
import okhttp3.OkHttpClient
import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory
import java.security.SecureRandom
import java.util.concurrent.TimeUnit
import javax.net.ssl.HostnameVerifier
import javax.net.ssl.SSLContext
import javax.net.ssl.TrustManager
import javax.net.ssl.X509TrustManager


object ApiManager {
    private lateinit var commonRetrofit: Retrofit

    lateinit var userService: ServiceUser


    init {
        if (!::commonRetrofit.isInitialized) {
            val client = getUnsafeOkHttpClient().newBuilder()
            .connectTimeout(10, TimeUnit.SECONDS)
            .readTimeout(60, TimeUnit.SECONDS)
            .writeTimeout(20, TimeUnit.SECONDS)
            .addInterceptor(HeaderInterceptor())
            .build();

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

        if (!::userService.isInitialized) {
            userService = commonRetrofit.create(ServiceUser::class.java)
        }

    }

    @SuppressLint("CustomX509TrustManager")
    fun getUnsafeOkHttpClient(): OkHttpClient {
        try {
            // 创建一个信任所有证书的 TrustManager
            val trustAllCerts = arrayOf<TrustManager>(

                object : X509TrustManager {
                    override fun checkClientTrusted(
                        chain: Array<out java.security.cert.X509Certificate>?,
                        authType: String?
                    ) {
                    }

                    override fun checkServerTrusted(
                        chain: Array<out java.security.cert.X509Certificate>?,
                        authType: String?
                    ) {
                    }

                    override fun getAcceptedIssuers(): Array<java.security.cert.X509Certificate> =
                    arrayOf()
                }
            )

            // 初始化 SSLContext
            val sslContext = SSLContext.getInstance("TLS")
            sslContext.init(null, trustAllCerts, SecureRandom())

            // 创建一个允许所有主机名验证的 HostnameVerifier
            val allHostsValid = HostnameVerifier { _, _ -> true }

            // 创建 OkHttpClient 并配置 SSL 和主机名验证
            return OkHttpClient.Builder()
            .sslSocketFactory(sslContext.socketFactory, trustAllCerts[0] as X509TrustManager)
            .hostnameVerifier(allHostsValid)
            .build()
        } catch (e: Exception) {
            throw RuntimeException(e)
        }
    }
}

跳过证书验证

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@SuppressLint("CustomX509TrustManager")
fun getUnsafeOkHttpClient(): OkHttpClient {
    try {
        // 创建一个信任所有证书的 TrustManager
        val trustAllCerts = arrayOf<TrustManager>(

            object : X509TrustManager {
                override fun checkClientTrusted(
                    chain: Array<out java.security.cert.X509Certificate>?,
                    authType: String?
                ) {
                }

                override fun checkServerTrusted(
                    chain: Array<out java.security.cert.X509Certificate>?,
                    authType: String?
                ) {
                }

                override fun getAcceptedIssuers(): Array<java.security.cert.X509Certificate> =
                arrayOf()
            }
        )

        // 初始化 SSLContext
        val sslContext = SSLContext.getInstance("TLS")
        sslContext.init(null, trustAllCerts, SecureRandom())

        // 创建一个允许所有主机名验证的 HostnameVerifier
        val allHostsValid = HostnameVerifier { _, _ -> true }

        // 创建 OkHttpClient 并配置 SSL 和主机名验证
        return OkHttpClient.Builder()
        .sslSocketFactory(sslContext.socketFactory, trustAllCerts[0] as X509TrustManager)
        .hostnameVerifier(allHostsValid)
        .build()
    } catch (e: Exception) {
        throw RuntimeException(e)
    }
}

Service

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import retrofit2.Response
import retrofit2.http.Body
import retrofit2.http.GET
import retrofit2.http.POST

interface ServiceUser {
    
    data class LoginPara(
        var username: String = "",  // 用户名
        var password: String = "",  // 密码
    )

    @POST("/api/auth/login")
    suspend fun apiAuthLogin(@Body request: LoginPara): Response<ResultVo<UserModel>>
}