Get JSON from the URL properly

Question

I have the following method that gives me one String:

public static final String jsonClientes =

    " {\"clientes\": " +
            "  [" +
            "     { \"idClientesT\": 1," +
            "       \"tipo\":\"s\"," +
            "       \"nome\":\"Carlos\"" +
            "     }," +
            "     { \"idClientesT\": 2," +
            "       \"tipo\":\"s\"," +
            "       \"nome\":\"Rogério\"" +
            "     }" +
            "  ]" +
            "}";

And the following method to read the String above:

public void clientes(String jsonCli) {

    try {

        JSONObject clientes = new JSONObject(jsonCli);
        JSONArray arrayPlanetas = clientes.getJSONArray("clientes");

        for (int i = 0; i < arrayPlanetas.length(); i++) {

            JSONObject cliente = arrayPlanetas.getJSONObject(i);

            Log.d("idClientesT", cliente.getString("idClientesT"));
            Log.d("tipo", cliente.getString("tipo"));
            Log.d("nome", cliente.getString("nome"));

        }

    } catch (JSONException e) {
        e.printStackTrace();
    }
}

The onCreate is like this:

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.form);

        clientes(jsonClientes);

    }

This way I can access the data normally.

Well, I have this URL that reads a return exactly like that:

{"clientes":[{"idClientesT":"1","tipo":"s","nome":"Carlos"},{"idClientesT":"2","tipo":"s","nome":"Rogério"}]}

But without the proper *scapes*.

I would like to know how in:

JSONArray arrayPlanetas = clientes.getJSONArray("clientes");

Instead of doing:

.getJSONArray("clientes");

could pick up the return from the URL like this:

.getJSONArray(url);

it is possible that?

How to do?

In an attempt (unsuccessfully) I did so:

package carcleo.com.radiosingular;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import carcleo.com.radiosingular.classes.JsonClass;

public class form extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.form);

        String url = "http://hotplateprensas.com.br/ws/clientest.php";
        JSONObject clientesLista = null;
        JsonClass json = new JsonClass();
        clientesLista = json.getJSONFromUrl(url);

        clientes(clientesLista);

    }

    public void clientes(JSONObject jsonCli) {

        try {

            JSONArray arrayPlanetas = jsonCli.getJSONArray("clientes");

            for (int i = 0; i < arrayPlanetas.length(); i++) {

                JSONObject cliente = arrayPlanetas.getJSONObject(i);

                Log.d("idClientesT", cliente.getString("idClientesT"));
                Log.d("tipo", cliente.getString("tipo"));
                Log.d("nome", cliente.getString("nome"));

            }

        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

}

and the class JsonClass

package carcleo.com.radiosingular.classes;

import android.util.Log;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;

import cz.msebera.android.httpclient.HttpEntity;
import cz.msebera.android.httpclient.HttpResponse;
import cz.msebera.android.httpclient.client.ClientProtocolException;
import cz.msebera.android.httpclient.client.methods.HttpPost;
import cz.msebera.android.httpclient.impl.client.DefaultHttpClient;

public class JsonClass {

    InputStream input = null;
    JSONObject jObect = null;
    String json = "";

    //Recebe sua url
    public JSONObject getJSONFromUrl(String url) {

        //HTTP request
        try {
            // default HttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            input = httpEntity.getContent();

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    input, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            input.close();
            json = sb.toString();
            Log.i("JRF", json);
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // Transforma a String de resposta em um JSonObject
        try {
            jObect = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // retorna o objeto
        return jObect;

    }
}

That gives me the following mistake:

12/14 14:25:05: Launching app
$ adb install-multiple -r -t -p carcleo.com.radiosingular D:\Trabalhos\AndroidStudio\RadioSingular\app\build\intermediates\split-apk\debug\slices\slice_8.apk 
Split APKs installed in 1 s 53 ms
$ adb shell am start -n "carcleo.com.radiosingular/carcleo.com.radiosingular.login" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Client not ready yet..Connected to process 13274 on device motorola-moto_g_play-0027377835
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
W/System: ClassLoader referenced unknown path: /data/app/carcleo.com.radiosingular-2/lib/arm
I/InstantRun: starting instant run server: is main process
I/Adreno-EGL: <qeglDrvAPI_eglInitialize:379>: EGL 1.4 QUALCOMM build: Nondeterministic_AU_msm8916_32_LA.BR.1.2.9_RB1__release_AU (I750f7f2fa6)
    OpenGL ES Shader Compiler Version: XE031.09.00.03
    Build Date: 02/18/17 Sat
    Local Branch: 
    Remote Branch: quic/LA.BR.1.2.9_rb1.12
    Local Patches: NONE
    Reconstruct Branch: NOTHING
I/OpenGLRenderer: Initialized EGL, version 1.4
D/OpenGLRenderer: Swap behavior 1
W/Adreno-ES20: <get_gpu_clk:229>: open failed: errno 13
W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
I/art: Rejecting re-init on previously-failed class java.lang.Class<android.support.v4.view.ViewCompat$OnUnhandledKeyEventListenerWrapper>: java.lang.NoClassDefFoundError: Failed resolution of: Landroid/view/View$OnUnhandledKeyEventListener;
I/art:     at void android.support.v4.view.ViewCompat.setBackground(android.view.View, android.graphics.drawable.Drawable) (ViewCompat.java:2341)
        at void android.support.v7.widget.ActionBarContainer.<init>(android.content.Context, android.util.AttributeSet) (ActionBarContainer.java:62)
        at java.lang.Object java.lang.reflect.Constructor.newInstance0!(java.lang.Object[]) (Constructor.java:-2)
        at java.lang.Object java.lang.reflect.Constructor.newInstance(java.lang.Object[]) (Constructor.java:430)
        at android.view.View android.view.LayoutInflater.createView(java.lang.String, java.lang.String, android.util.AttributeSet) (LayoutInflater.java:645)
        at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:787)
        at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet) (LayoutInflater.java:727)
        at void android.view.LayoutInflater.rInflate(org.xmlpull.v1.XmlPullParser, android.view.View, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:858)
        at void android.view.LayoutInflater.rInflateChildren(org.xmlpull.v1.XmlPullParser, android.view.View, android.util.AttributeSet, boolean) (LayoutInflater.java:821)
        at android.view.View android.view.LayoutInflater.inflate(org.xmlpull.v1.XmlPullParser, android.view.ViewGroup, boolean) (LayoutInflater.java:518)
        at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup, boolean) (LayoutInflater.java:426)
        at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup) (LayoutInflater.java:377)
        at android.view.ViewGroup android.support.v7.app.AppCompatDelegateImpl.createSubDecor() (AppCompatDelegateImpl.java:607)
        at void android.support.v7.app.AppCompatDelegateImpl.ensureSubDecor() (AppCompatDelegateImpl.java:518)
        at void android.support.v7.app.AppCompatDelegateImpl.setContentView(int) (AppCompatDelegateImpl.java:466)
        at void android.support.v7.app.AppCompatActivity.setContentView(int) (AppCompatActivity.java:140)
        at void carcleo.com.radiosingular.form.onCreate(android.os.Bundle) (form.java:18)
        at void android.app.Activity.performCreate(android.os.Bundle) (Activity.java:6687)
        at void android.app.Instrumentation.callActivityOnCreate(android.app.Activity, android.os.Bundle) (Instrumentation.java:1140)
        at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2631)
        at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:2743)
        at void android.app.ActivityThread.-wrap12(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
        at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1490)
        at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:102)
        at void android.os.Looper.loop() (Looper.java:154)
        at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6165)
        at java.lang.Object java.lang.reflect.Method.invoke!(java.lang.Object, java.lang.Object[]) (Method.java:-2)
        at void com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run() (ZygoteInit.java:888)
        at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:778)
    Caused by: java.lang.ClassNotFoundException: Didn't find class "android.view.View$OnUnhandledKeyEventListener" on path: DexPathList[[zip file "/data/app/carcleo.com.radiosingular-2/base.apk", zip file "/data/app/carcleo.com.radiosingular-2/split_lib_dependencies_apk.apk", zip file "/data/app/carcleo.com.radiosingular-2/split_lib_slice_0_apk.apk", zip file "/data/app/carcleo.com.radiosingular-2/split_lib_slice_1_apk.apk", zip file "/data/app/carcleo.com.radiosingular-2/split_lib_slice_2_apk.apk", zip file "/data/app/carcleo.com.radiosingular-2/split_lib_slice_3_apk.apk", zip file "/data/app/carcleo.com.radiosingular-2/split_lib_slice_4_apk.apk", zip file "/data/app/carcleo.com.radiosingular-2/split_lib_slice_5_apk.apk", zip file "/data/app/carcleo.com.radiosingular-2/split_lib_slice_6_apk.apk", zip file "/data/app/carcleo.com.radiosingular-2/split_lib_slice_7_apk.apk", zip file "/data/app/carcleo.com.radiosingular-2/split_lib_slice_8_apk.apk", zip file "/data/app/carcleo.com.radiosingular-2/split_lib_slice_9_
        at java.lang.Class dalvik.system.BaseDexClassLoader.findClass(java.lang.String) (BaseDexClassLoader.java:56)
        at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String, boolean) (ClassLoader.java:380)
        at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String) (ClassLoader.java:312)
        at void android.support.v4.view.ViewCompat.setBackground(android.view.View, android.graphics.drawable.Drawable) (ViewCompat.java:2341)
        at void android.support.v7.widget.ActionBarContainer.<init>(android.content.Context, android.util.AttributeSet) (ActionBarContainer.java:62)
        at java.lang.Object java.lang.reflect.Constructor.newInstance0!(java.lang.Object[]) (Constructor.java:-2)
        at java.lang.Object java.lang.reflect.Constructor.newInstance(java.lang.Object[]) (Constructor.java:430)
        at android.view.View android.view.LayoutInflater.createView(java.lang.String, java.lang.String, android.util.AttributeSet) (LayoutInflater.java:645)
        at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:787)
        at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet) (LayoutInflater.java:727)
        at void android.view.LayoutInflater.rInflate(org.xmlpull.v1.XmlPullParser, android.view.View, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:858)
        at void android.view.LayoutInflater.rInflateChildren(org.xmlpull.v1.XmlPullParser, android.view.View, android.util.AttributeSet, boolean) (LayoutInflater.java:821)
        at android.view.View android.view.LayoutInflater.inflate(org.xmlpull.v1.XmlPullParser, android.view.ViewGroup, boolean) (LayoutInflater.java:518)
        at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup, boolean) (LayoutInflater.java:426)
        at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup) (LayoutInflater.java:377)
        at android.view.ViewGroup android.support.v7.app.AppCompatDelegateImpl.createSubDecor() (AppCompatDelegateImpl.java:607)
        at void android.support.v7.app.AppCompatDelegateImpl.ensureSubDecor() (AppCompatDelegateImpl.java:518)
        at void android.support.v7.app.AppCompatDelegateImpl.setContentView(int) (AppCompatDelegateImpl.java:466)
        at void android.support.v7.app.AppCompatActivity.setContentView(int) (AppCompatActivity.java:140)
        at void carcleo.com.radiosingular.form.onCreate(android.os.Bundle) (form.java:18)
        at void android.app.Activity.performCreate(android.os.Bundle) (Activity.java:6687)
        at void android.app.Instrumentation.callActivityOnCreate(android.app.Activity, android.os.Bundle) (Instrumentation.java:1140)
        at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2631)
        at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:2743)
        at void android.app.ActivityThread.-wrap12(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
        at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1490)
        at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:102)
        at void android.os.Looper.loop() (Looper.java:154)
        at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6165)
        at java.lang.Object java.lang.reflect.Method.invoke!(java.lang.Object, java.lang.Object[]) (Method.java:-2)
        at void com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run() (ZygoteInit.java:888)
        at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:778)
D/NetworkSecurityConfig: No Network Security Config specified, using platform default
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
    Process: carcleo.com.radiosingular, PID: 13274
    java.lang.RuntimeException: Unable to start activity ComponentInfo{carcleo.com.radiosingular/carcleo.com.radiosingular.form}: android.os.NetworkOnMainThreadException
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2678)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2743)
        at android.app.ActivityThread.-wrap12(ActivityThread.java)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1490)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6165)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:778)
     Caused by: android.os.NetworkOnMainThreadException
        at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1317)
        at java.net.Inet6AddressImpl.lookupHostByName(Inet6AddressImpl.java:86)
        at java.net.Inet6AddressImpl.lookupAllHostAddr(Inet6AddressImpl.java:74)
        at java.net.InetAddress.getAllByName(InetAddress.java:752)
        at cz.msebera.android.httpclient.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:44)
        at cz.msebera.android.httpclient.impl.conn.DefaultClientConnectionOperator.resolveHostname(DefaultClientConnectionOperator.java:259)
        at cz.msebera.android.httpclient.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:159)
        at cz.msebera.android.httpclient.impl.conn.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:304)
        at cz.msebera.android.httpclient.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:611)
        at cz.msebera.android.httpclient.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:446)
        at cz.msebera.android.httpclient.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:860)
        at cz.msebera.android.httpclient.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
        at cz.msebera.android.httpclient.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:106)
        at carcleo.com.radiosingular.classes.JsonClass.getJSONFromUrl(JsonClass.java:35)
        at carcleo.com.radiosingular.form.onCreate(form.java:23)
        at android.app.Activity.performCreate(Activity.java:6687)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1140)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2631)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2743) 
        at android.app.ActivityThread.-wrap12(ActivityThread.java) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1490) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:154) 
        at android.app.ActivityThread.main(ActivityThread.java:6165) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:778) 

Answer 1

I found that by adding the código down to the oncreate, the system works properly.

if (android.os.Build.VERSION.SDK_INT > 9){
    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy);
}

But I don’t quite understand.

From the code, the impression I have is that it will only work for Devices with versions of Android above 9.0?

That’s right?

And for earlier versions? What to do?

Note: If I do not put this block of code gives the following error:

D/NetworkSecurityConfig: No Network Security Config specified, using platform default

Answer 2

To support earlier versions go to build.gradle which is in the "app" folder and changes the property minSdkVersion for which version of the SDK you want to support.