Android Studio，Db 連接錯誤：發生異常情況導致驅動程序失敗。 請報告此異常

Question

我開始這個討論是因為我有一個關於我正在處理的 Android 學校項目的大問題。 現在我有一個在線服務 ElephantSQL 的免費數據庫。

該數據庫非常完美，因為當我嘗試使用 IntelliJIDEA 將其連接到用 java 編寫的項目時，一切正常。 但是，如果我嘗試使用用 Kotlin 編寫的代碼在 Android Studio 中使用相同的憑據（ip、用戶名、密碼等）連接數據庫，則每次連接都會失敗。

我整天都在研究這個問題，我已經嘗試了我在互聯網上找到的所有解決方案，但它仍然不起作用。

這是我的 build.gradle 文件依賴項

plugins {
    id 'com.android.application'
    id 'org.jetbrains.kotlin.android'
}

android {
    compileSdk 31

    defaultConfig {
        applicationId "com.example.myapplication"
        minSdk 21
        targetSdk 31
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = '1.8'
    }
}

dependencies {

    implementation 'org.postgresql:postgresql:42.2.5.jre7'

    implementation 'net.sourceforge.jtds:jtds:1.3.1'
    implementation 'androidx.core:core-ktx:1.7.0'
    implementation 'androidx.appcompat:appcompat:1.4.1'
    implementation 'com.google.android.material:material:1.5.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.3'
    testImplementation 'junit:junit:4.13.2'
    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
}

這是我的代碼

package com.example.myapplication

import android.Manifest
import android.content.pm.PackageManager
import android.os.Bundle
import android.os.StrictMode
import android.os.StrictMode.ThreadPolicy
import android.util.Log
import android.view.View
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat
import java.sql.Connection
import java.sql.DriverManager
import java.sql.SQLException


var username = "myUsername";
var password = "password";
var  url = "jdbc:postgresql://tyke.db.elephantsql.com:5432/myUsername";
private var connection: Connection? = null

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

}
    fun start(view: View?) {
        ActivityCompat.requestPermissions(
            this,
            arrayOf(Manifest.permission.INTERNET),
            PackageManager.PERMISSION_GRANTED
        )
        val policy = ThreadPolicy.Builder().permitAll().build()
        StrictMode.setThreadPolicy(policy)
        try {
            Class.forName("org.postgresql.Driver")
            connection = DriverManager.getConnection(url, username, password)
            Toast.makeText(this, "Connected", Toast.LENGTH_SHORT).show()
            Log.d("client","connected")
        } catch (e: ClassNotFoundException) {
            e.printStackTrace()
            Toast.makeText(this, "Class fail", Toast.LENGTH_SHORT).show()
            Log.d("client","1 not connected")
        } catch (e: SQLException) {
            e.printStackTrace()
            Log.d("client","2 not connected"+e)
            Toast.makeText(this, "Connected no", Toast.LENGTH_SHORT).show()
        }
    }
}

這是每次都會出現的錯誤

org.postgresql.util.PSQLException：連接嘗試失敗。

我希望能得到一點幫助，因為我被困住了，我不知道該怎么辦。 先感謝您！

*這是錯誤的完整堆棧跟蹤，也許它可以提供幫助！

2022-05-25 10:28:25.143 20453-20453/com.example.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.myapplication, PID: 20453
    java.lang.IllegalStateException: Could not execute method for android:onClick
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:446)
        at android.view.View.performClick(View.java:7125)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1131)
        at android.view.View.performClickInternal(View.java:7102)
        at android.view.View.access$3500(View.java:801)
        at android.view.View$PerformClick.run(View.java:27336)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
     Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Method.invoke(Native Method)
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:441)
        at android.view.View.performClick(View.java:7125) 
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1131) 
        at android.view.View.performClickInternal(View.java:7102) 
        at android.view.View.access$3500(View.java:801) 
        at android.view.View$PerformClick.run(View.java:27336) 
        at android.os.Handler.handleCallback(Handler.java:883) 
        at android.os.Handler.dispatchMessage(Handler.java:100) 
        at android.os.Looper.loop(Looper.java:214) 
        at android.app.ActivityThread.main(ActivityThread.java:7356) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930) 
     Caused by: org.postgresql.util.PSQLException: The connection attempt failed.
        at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:292)
        at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
        at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:195)
        at org.postgresql.Driver.makeConnection(Driver.java:454)
        at org.postgresql.Driver.connect(Driver.java:256)
        at java.sql.DriverManager.getConnection(DriverManager.java:580)
        at java.sql.DriverManager.getConnection(DriverManager.java:218)
        at com.example.myapplication.MainActivity.start(MainActivity.kt:39)
        at java.lang.reflect.Method.invoke(Native Method) 
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:441) 
        at android.view.View.performClick(View.java:7125) 
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1131) 
        at android.view.View.performClickInternal(View.java:7102) 
        at android.view.View.access$3500(View.java:801) 
        at android.view.View$PerformClick.run(View.java:27336) 
        at android.os.Handler.handleCallback(Handler.java:883) 
        at android.os.Handler.dispatchMessage(Handler.java:100) 
        at android.os.Looper.loop(Looper.java:214) 
        at android.app.ActivityThread.main(ActivityThread.java:7356) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930) 
     Caused by: java.net.SocketException: socket failed: EPERM (Operation not permitted)
        at java.net.Socket.createImpl(Socket.java:492)
        at java.net.Socket.connect(Socket.java:619)
        at org.postgresql.core.PGStream.<init>(PGStream.java:70)
        at org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:91)
        at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:192)
        at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49) 
        at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:195) 
        at org.postgresql.Driver.makeConnection(Driver.java:454) 
        at org.postgresql.Driver.connect(Driver.java:256) 
        at java.sql.DriverManager.getConnection(DriverManager.java:580) 
        at java.sql.DriverManager.getConnection(DriverManager.java:218) 
        at com.example.myapplication.MainActivity.start(MainActivity.kt:39) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:441) 
        at android.view.View.performClick(View.java:7125) 
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1131) 
        at android.view.View.performClickInternal(View.java:7102) 
        at android.view.View.access$3500(View.java:801) 
        at android.view.View$PerformClick.run(View.java:27336) 
        at android.os.Handler.handleCallback(Handler.java:883) 
        at android.os.Handler.dispatchMessage(Handler.java:100) 
        at android.os.Looper.loop(Looper.java:214) 
        at android.app.ActivityThread.main(ActivityThread.java:7356) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930) 

Answer 1

經過幾天的挖掘，我終於能夠解決我的問題。

當您編輯 android manifest 時，您必須從模擬器中卸載（手動）您的應用程序並重新安裝它。 這是使更改最終確定的唯一方法。

所以，我的問題很簡單……如果以后有人遇到同樣的情況，親愛的朋友試試我的解決方案！