Question

我正在本地计算机服务器（localhost）的端口8080上运行Sample Spring Boot应用程序。从客户端应用程序，我试图通过Kotlin Retrofit在Android Studio 仿真器中发出发布请求>，

科特林码

interface RestApi {

    @Headers("Content-Type: application/json")
    @POST("users")
    fun addUser(@Body userData: CTUserInfo): Call<ResponseBody>
}


object ServiceBuilder {
    private val client = OkHttpClient.Builder().build()

    private val retrofit = Retrofit.Builder()
        .baseUrl("http://localhost:8080/")
        .addConverterFactory(GsonConverterFactory.create())
        .client(client)
        .build()

    fun<T> buildService(service: Class<T>): T{
        return retrofit.create(service)
    }
}

class RestApiService {

    fun addUser(userData: CTUserInfo){

        val retrofit = ServiceBuilder.buildService(RestApi::class.java)

        retrofit.addUser(userData).enqueue(
            object : Callback<ResponseBody> {

                override fun onFailure(call: Call<ResponseBody>, t: Throwable) {
                    // failure
                    print("Failed") // getting t = below mentioned error
                }

                override fun onResponse( call: Call<ResponseBody>, response: Response<ResponseBody>) {

                    if (response.code() == 201) {
                        // user added
                        print("Success")
                    } else{
                        //user could not be added
                        print("Failed")
                    }
                }
            }
        )
    }
}

我遇到以下错误：

java.net.ConnectException：10000毫秒后无法从/127.0.0.1（端口57452）连接到localhost / 127.0.0.1（端口8080）：isConnected失败：ECONNREFUSED（连接被拒绝）

但是，当我尝试从Postman发帖时，它会在http://localhost:8080/users上成功发送。

如何解决？

更新

我的Android清单文件看起来像

    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />

    <application
            android:name=".BaseApplication"
            android:allowBackup="true"
            android:icon="@mipmap/ic_launcher"
            android:label="@string/app_name"
            android:roundIcon="@mipmap/ic_launcher_round"
            android:supportsRtl="true"
            android:usesCleartextTraffic="true"
            android:theme="@style/AppTheme">
            ...

Answer 1

您是否已在清单中添加了许可互联网？如果您在API为Pie的新设备上进行测试，则必须添加清晰的teext流量。像这样：

 <application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme"
    android:usesCleartextTraffic="true">

Answer 2

您可以尝试添加res / values / xml / network_security_config.xml

<?xml version="1.0" encoding="utf-8"?>
    <network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">http://localhost:8080/</domain>
    </domain-config>
</network-security-config>

并在标签应用程序内的清单中引用此内容

<application
...
    android:networkSecurityConfig="@xml/network_security_config"
...
</application>

Answer 3

最后，我通过添加在bash中运行以下命令找到的实际机器IP解决了该问题

Mac-ifconfig
Windows-ipconfig /all

示例

private val retrofit = Retrofit.Builder()
    .baseUrl("http://192.168.64.1:8080/")
    .addConverterFactory(GsonConverterFactory.create())
    .client(client)
    .build()

获取isConnected失败：Kotlin Retrofit发布请求的ECONNREFUSED（连接被拒绝）错误

科特林码

更新

3 个答案: