Android Studio，Db 连接错误：发生异常情况导致驱动程序失败。 请报告此异常

Question

I'm opening this discussion because I have a big issue regarding a school project in Android that I'm working on. Right now I have a free database with the online service ElephantSQL.

The database is perfect because when I try to connect it to a project written in java using IntelliJIDEA everything works fine. However, if I try to connect the database with the same credentials (ip, username, password etc) in Android Studio with code written in Kotlin, the connection fails everytime.

I've been working on this the whole day and I've tried every solution I found on internet but it still doesn't work.

Here are my build.gradle file dependencies

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'
}

and this is my code

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()
        }
    }
}

This is the error that occurs every time

org.postgresql.util.PSQLException: The connection attempt failed.

I'm hoping for a little help because I'm stuck and I don't know what to do. Thank you in advance!

*This is the full stack trace of error, maybe it can be of help!

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

after a few days of digging, i was finally able to manage a solution for my problem.

When you edit the android manifest, you must uninstall (manually) your app from your emulator and reinstall it. It's the only way to make the changement definitive.

So, my problem was simply that... If someone in the future will be in the same situation, dear friend try my solution!