CODEWITHSUNDEEP
javaandroidjsononclickhttpurlconnection
noitse
noitse

Reputation: 1045

Android studio httpURLConnection app crash

I am new to Android and Java development , i am working as web developer and wanted to learn Android studio and java.

As always when learning new language , first thing I do is some database call, in this just JSON call.

Using httpURLConnection , i have found example online and it works in my main function when i run it in android studio, but when I put it inside button on click function and run my app on my mobile, my app crashes.

I have also added To AndroidManifest.xml inside manifest tags.

Here is error i get

11-22 19:47:46.354 24975-24975/com.example.adis.myapp I/System.out: I am here//////////////////////////////////////////
11-22 19:47:46.494 24975-24975/com.example.adis.myapp D/AndroidRuntime: Shutting down VM
11-22 19:47:46.494 24975-24975/com.example.adis.myapp W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x41659e00)
11-22 19:47:46.514 24975-24975/com.example.adis.myapp E/AndroidRuntime: FATAL EXCEPTION: main

                 Process: com.example.adis.myapp, PID: 24975
                    java.lang.IllegalStateException: Could not execute method for android:onClick
                        at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
                ive Method)
                     Caused by: java.lang.reflect.InvocationTargetException
                        at java.lang.reflect.Method.invokeNative(Native Method)
                        at java.lang.reflect.Method.invoke(Method.java:515)
                        at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
                        at android.view.View.performClick(View.java:4457) 
                        at android.view.View$PerformClick.run(View.java:18491) 
                        at android.os.Handler.handleCallback(Handler.java:733) 
                        at android.os.Handler.dispatchMessage(Handler.java:95) 
                        at android.os.Looper.loop(Looper.java:136) 
                        at android.app.ActivityThread.main(ActivityThread.java:5333) 
                        at java.lang.reflect.Method.invokeNative(Native Method) 
                        at java.lang.reflect.Method.invoke(Method.java:515) 
                        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:895) 
                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:711) 
                        at dalvik.system.NativeStart.main(Native Method) 
                     Caused by: android.os.NetworkOnMainThreadException
                        at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1148)
                        at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
                        at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
                        at java.net.InetAddress.getAllByName(InetAddress.java:214)
                        at com.android.okhttp.internal.Dns$1.getAllByName(Dns.java:28)
                        at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:216)
                        at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:122)
                        at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:292)
                        at com.android.okhttp.internal.http.HttpEngine.sendSocketRequest(HttpEngine.java:255)
                        at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:206)
                        at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:345)
                        at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:296)
                        at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:503)
                        at com.example.adis.myapp.MainActivity.loginFunction(MainActivity.java:85)
                        at java.lang.reflect.Method.invokeNative(Native Method) 
                        at java.lang.reflect.Method.invoke(Method.java:515) 
                        at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) 
                        at android.view.View.performClick(View.java:4457) 
                        at android.view.View$PerformClick.run(View.java:18491) 
                        at android.os.Handler.handleCallback(Handler.java:733) 
                        at android.os.Handler.dispatchMessage(Handler.java:95) 
                        at android.os.Looper.loop(Looper.java:136) 
                        at android.app.ActivityThread.main(ActivityThread.java:5333) 
                        at java.lang.reflect.Method.invokeNative(Native Method) 
                        at java.lang.reflect.Method.invoke(Method.java:515) 
                        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:895) 
                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:711) 
                        at dalvik.system.NativeStart.main(Native Method) 
11-22 19:47:46.524 923-1275/? W/ActivityManager:   Force finishing activity com.example.adis.myapp/.MainActivity

Here is my onClick function 

public void loginFunction(View view) throws IOException, JSONException {


    System.out.println("I am here//////////////////////////////////////////");
    try {

        URL url = new URL("http://echo.jsontest.com/insert-key-here/insert-value-here/key/value");
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("GET");
        conn.setRequestProperty("Accept", "application/json");

        if (conn.getResponseCode() != 200) {
            throw new RuntimeException("Failed : HTTP error code : "
                    + conn.getResponseCode());
        }

        BufferedReader br = new BufferedReader(new InputStreamReader(
                (conn.getInputStream())));

        String output;
        System.out.println("Output from Server .... \n");
        while ((output = br.readLine()) != null) {
            System.out.println(output);
        }

        conn.disconnect();

    } catch (MalformedURLException e) {

        e.printStackTrace();

    } catch (IOException e) {

        e.printStackTrace();

    }



}

Be harsh on me if you see some stupid mistake even java beginner should see, because i don't .

Thank you for stopping by :)

Upvotes: 2

Views: 7574

Answers (2)

Shubham Gupta
Shubham Gupta

Reputation: 159

  1. Add this to your AndroidManifest.xml before Application tag:-

    <uses-permission android:name="android.permission.INTERNET"/> <application ..... </application>

  2. Even on trivial internet connection HTTP requests can take huge time thus freezing the Main UI thread. What you can do is start a new AsyncTask when button is hit.

    Put the code in separate class like :-

    public class HTTPRequestTask extends AsyncTask<Void, Void, Void> {

@Override
protected Void doInBackground(Void... params){
System.out.println("I am   here//////////////////////////////////////////");
try {
URL url = new URL("http://echo.jsontest.com/insert-key-here/insert-value-here/key/value");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setRequestProperty("Accept", "application/json");

if (conn.getResponseCode() != 200) {
    throw new RuntimeException("Failed : HTTP error code : "
            + conn.getResponseCode());
}

BufferedReader br = new BufferedReader(new InputStreamReader(
        (conn.getInputStream())));

String output;
System.out.println("Output from Server .... \n");
while ((output = br.readLine()) != null) {
    System.out.println(output);
}

conn.disconnect();

} catch (MalformedURLException e) {

   e.printStackTrace();

} catch (IOException e) {

   e.printStackTrace();

}

    And modify the onClickButton like :-

    OnButtonclick(...){ ... HTTPRequestTask testTask =new HTTPRequestTask(); testTask.execute(); ...}

    PS - I have named the new class as HTTPRequestTask. You can choose your own name.

Upvotes: 3

mWhitley
mWhitley

Reputation: 453

You're not allowed to make a network connection on the main thread since this can freeze the UI thread and make your app unresponsive. That is why the exception is thrown.

You can make the button fire off a new thread or AsyncTask to complete the action.

Example: How to fix android.os.NetworkOnMainThreadException?

Upvotes: 3

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