An StreamReader is not passing data error in JAVA

Question

Good evning! I'm trying build an app that pass the HTML code from an URL to an InputStreamReader and set it on a TextView. I tried to do it on a different Thread.

(new Thread(new Runnable() {

            @Override
            public void run() {
                TextView textView = (TextView) findViewById(R.id.text);
                textView.setText("0.0");
                InputStream inputStream;
                URL url = null;
                InputStreamReader inputStreamReader;
                char c;
                String s = "";
                try {

                    url = new URL ("https://www.blank.org/");
                    inputStream = url.openConnection().getInputStream();
                    inputStreamReader = new InputStreamReader(inputStream);
                    do{
                        c = (char) inputStreamReader.read();
                        s+= c;
                    }while (c!=-1);
                    textView.setText(":)");
                }catch (Exception E){
                    textView.setText(":(");
                    Log.i("Error", ":(");
                }

            }
        })).start();

The app is crushing even so I have the code on try & catch, and I'm getting this error:

E/Conscrypt: ------------------Untrusted chain: ----------------------
    == Chain0 == 
     Version:   3
     Serial Number:   558b384c9801a191d4edb12f6c7f5152
E/Conscrypt:  SubjectDN:   CN=www.blank.org, OU=PositiveSSL Multi-Domain, OU=Domain Control Validated
E/Conscrypt:  IssuerDN:   CN=COMODO RSA Domain Validation Secure Server CA, O=COMODO CA Limited, L=Salford, ST=Greater Manchester, C=GB
E/Conscrypt:  Get not before:   Tue Sep 04 03:00:00 GMT+03:00 2018
     Get not after:   Sun Nov 03 01:59:59 GMT+02:00 2019
     Sig ALG name:   SHA256withRSA
     Signature:   4b60d0478a19ef41d8549347efb9ccc91438ac2261b6f248ae0260b774f2516f5f92e80dfec433ff4ba635dd20a2cc82643eb8972ae95560548a02746e22b2335e76ef68b36ea4ca1de851984e5a1b8da5f716e157ef474eeb7d8a75f61a48fad9b70124eb40e92870b772cb9299e59ebf9d44e4e359407a86c6b3615c2d2925692a62ff40aa11972f94c78a796f7a7a340aed338f2a6d8476c784430419afdbedb2921efc3601085d3cd267785d8a58d3a488a576acc213a877a80f748795e5f0056e2a3dbb8b824efc5a664eb6833ab89a8037369c021178183e6b361ba9b7f1bfc4fc2c2b579f2b0bdde7f9fa72031257c368ac3106943c1e77ea4eea96b3
E/Conscrypt:  Public key:

     30 82 01 22 30 0d 06 09 2a 86 48 86 f7 0d 01 01 01 05 00 03
     82 01 0f 00 30 82 01 0a 02 82 01 01 00 d0 78 ff 2c 2c d0 51
     d4 3a da d2 b1 aa 89 89 07 01 78 ca 67 16 b8 49 a4 39 b8 ed
     eb 48 a6 0b a3 d1 da 41 a8 82 e8 c9 55 33 ae 3c 21 24 24 e4
     b0 70 ac d8 ee 10 5c 2d aa 7d 2d e2 ef 37 ec ba 16 f9 66 a0
     c8 59 f0 03 12 6b ef d9 ee 43 43 82 05 e4 79 ea 67 a1 fc ea
     ac 57 84 cd 98 16 df dd b5 2d d1 e6 5f 43 df 1d ad fc 8a 33
     d0 4a 52 f1 43 0d 84 45 bf a3 77 90 69 37 15 bb e4 81 7a 7b
     05 81 c0 f3 ab 92 fa d9 22 17 47 f0 c1 bd f1 e4 1e db d0 bb
     93 f7 10 8a e4 81 8a 3a 3a f6 89 2d 7f 31 2a ad 8a 5d 2a ca
     25 a9 76 7b 06 83 84 ae 3f 69 64 72 a1 94 4d 39 57 fa 26 fe
     07 4a 78 82 41 8c 58 5c f0 b4 05 71 e3 69 33 10 90 00 9c 7a
     37 af dd d2 a9 3f 04 fa d8 9b 4f db 0e de 59 3a c2 21 4e d1
     68 00 47 15 f9 bc 2b 52 7d 31 31 26 f3 26 b6 27 3f 83 85 6f
     45 5c 5d 21 b9 d4 dc 60 3f 02 03 01 00 01
E/AndroidRuntime: FATAL EXCEPTION: Thread-7
    Process: com.mayli.downloadinternetcontent, PID: 7203
    android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
        at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:8525)
        at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:1427)
        at android.view.View.requestLayout(View.java:23221)
        at android.view.View.requestLayout(View.java:23221)
        at android.view.View.requestLayout(View.java:23221)
        at android.view.View.requestLayout(View.java:23221)
        at android.view.View.requestLayout(View.java:23221)
        at android.view.View.requestLayout(View.java:23221)
        at android.support.constraint.ConstraintLayout.requestLayout(ConstraintLayout.java:3172)
        at android.view.View.requestLayout(View.java:23221)
        at android.widget.TextView.checkForRelayout(TextView.java:9789)
        at android.widget.TextView.setText(TextView.java:6023)
        at android.widget.TextView.setText(TextView.java:5849)
        at android.widget.TextView.setText(TextView.java:5806)
        at com.mayli.downloadinternetcontent.MainActivity$1.run(MainActivity.java:63)
        at java.lang.Thread.run(Thread.java:764)
D/ViewRootImpl@d02c10d[MainActivity]: MSG_WINDOW_FOCUS_CHANGED 0
D/OpenGLRenderer: eglDestroySurface = 0x7527f284c0
D/ViewRootImpl@d02c10d[MainActivity]: Relayout returned: old=[0,0][1080,1920] new=[0,0][1080,1920] result=0x5 surface={valid=false 0} changed=true
D/ViewRootImpl@d02c10d[MainActivity]: dispatchDetachedFromWindow
D/InputEventReceiver: channel '24e04ec com.mayli.downloadinternetcontent/com.mayli.downloadinternetcontent.MainActivity (client)' ~ Disposing input event receiver.
    channel '24e04ec com.mayli.downloadinternetcontent/com.mayli.downloadinternetcontent.MainActivity (client)' ~NativeInputEventReceiver.
Application terminated.

Can you please healp me solve this problem? Thanks in advance!

Mr00Anderson · Accepted Answer · 2019-03-25T19:34:20.553

Because you are accessing user interface objects through a non UI Thread. Attached is a source describing your error. Android UI Threads. I do not use android specifically.

Basically you must submit UI changes to the UI API. You usually do this in most languages with a new Runnable, or task and submit it. For android I have provided references.Activity#runOnUiThread(), Update ui from another thread in android - SO.

   (new Thread(new Runnable() {

            @Override
            public void run() {

                TextView textView = (TextView) findViewById(R.id.text);

                Runnable one = new Runnable(){
                    @Override
                    public void run() {
                        textView.setText("0.0");
                    }
                };

                Activity.runOnUiThread(one);

                InputStream inputStream;
                URL url = null;
                InputStreamReader inputStreamReader;
                char c;
                String s = "";
                try {

                    url = new URL ("https://www.blank.org/");
                    inputStream = url.openConnection().getInputStream();
                    inputStreamReader = new InputStreamReader(inputStream);
                    do{
                        c = (char) inputStreamReader.read();
                        s+= c;
                    }while (c!=-1);


                    Runnable two = new Runnable() {
                        @Override
                        public void run() {
                            textView.setText(":)");
                        }
                    };

                    Activity.runOnUiThread(two);

                }catch (Exception E){


                    Runnable three = new Runnable() {
                        @Override
                        public void run() {
                            textView.setText(":(");
                        }
                    };

                    Activity.runOnUiThread(three);

                    Log.i("Error", ":(");
                }

            }
        })).start();

Added sample, so while this may need a edit or two. This should give you an idea. Any updates on the GUI objects must be through the GUI API. — Mr00Anderson, Mar 25 '19 at 19:35

An StreamReader is not passing data error in JAVA

1 Answers1