I am trying to show response on screen using text view after clicking a button but getting error saying com.android.volley.toolbox.JsonObjectRequest cannot be cast to java.lang.CharSequence
package com.example.volleydemo;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONException;
import org.json.JSONObject;
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
Button Click;
TextView response;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Click = findViewById(R.id.button);
response=findViewById(R.id.textView);
Click.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
RequestQueue requestQueue;
requestQueue = Volley.newRequestQueue(getApplicationContext());
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET,
"https://jsonplaceholder.typicode.com/todos/1",
null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
Log.d("myapp", "the response is" response.getString("title"));
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void one rrorResponse(VolleyError error) {
Log.d("myapp", "something went wrong");
}
});
requestQueue.add(jsonObjectRequest);
response.setText((CharSequence) jsonObjectRequest);
}
});
}
}
XML code here
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@ id/Click"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="@ id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Click"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@ id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="36sp"
app:layout_constraintBottom_toTopOf="@ id/button"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.693" />
</androidx.constraintlayout.widget.ConstraintLayout>
errors on logcat shows i am getting this because at line 55 we can't use char sequence.so how do we get the response to textview
05/12 18:17:11: Launching 'app' on Pixel 2 API 30.
Install successfully finished in 40 s 997 ms.
$ adb shell am start -n "com.example.volleydemo/com.example.volleydemo.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Connected to process 3719 on device 'Pixel_2_API_30 [emulator-5554]'.
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
D/NetworkSecurityConfig: No Network Security Config specified, using platform default
D/NetworkSecurityConfig: No Network Security Config specified, using platform default
D/libEGL: loaded /vendor/lib/egl/libEGL_emulation.so
D/libEGL: loaded /vendor/lib/egl/libGLESv1_CM_emulation.so
D/libEGL: loaded /vendor/lib/egl/libGLESv2_emulation.so
W/mple.volleydem: Accessing hidden method Landroid/view/View;->computeFitSystemWindows(Landroid/graphics/Rect;Landroid/graphics/Rect;)Z (greylist, reflection, allowed)
W/mple.volleydem: Accessing hidden method Landroid/view/ViewGroup;->makeOptionalFitsSystemWindows()V (greylist, reflection, allowed)
D/HostConnection: HostConnection::get() New Host Connection established 0xef161170, tid 3750
D/HostConnection: HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_native_sync_v3 ANDROID_EMU_native_sync_v4 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_host_composition_v1 ANDROID_EMU_host_composition_v2 ANDROID_EMU_vulkan ANDROID_EMU_deferred_vulkan_commands ANDROID_EMU_vulkan_null_optional_strings ANDROID_EMU_vulkan_create_resources_with_requirements ANDROID_EMU_YUV_Cache ANDROID_EMU_vulkan_ignored_handles ANDROID_EMU_has_shared_slots_host_memory_allocator ANDROID_EMU_vulkan_free_memory_sync ANDROID_EMU_vulkan_shader_float16_int8 ANDROID_EMU_vulkan_async_queue_submit ANDROID_EMU_sync_buffer_data ANDROID_EMU_read_color_buffer_dma GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_gles_max_version_2
W/OpenGLRenderer: Failed to choose config with EGL_SWAP_BEHAVIOR_PRESERVED, retrying without...
D/EGL_emulation: eglCreateContext: 0xef160a70: maj 2 min 0 rcv 2
D/EGL_emulation: eglMakeCurrent: 0xef160a70: ver 2 0 (tinfo 0xef4ae4d0) (first time)
I/Gralloc4: mapper 4.x is not supported
D/HostConnection: createUnique: call
D/HostConnection: HostConnection::get() New Host Connection established 0xef160df0, tid 3750
D/goldfish-address-space: allocate: Ask for block of size 0x100
D/goldfish-address-space: allocate: ioctl allocate returned offset 0x3f7ffe000 size 0x2000
D/HostConnection: HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_native_sync_v3 ANDROID_EMU_native_sync_v4 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_host_composition_v1 ANDROID_EMU_host_composition_v2 ANDROID_EMU_vulkan ANDROID_EMU_deferred_vulkan_commands ANDROID_EMU_vulkan_null_optional_strings ANDROID_EMU_vulkan_create_resources_with_requirements ANDROID_EMU_YUV_Cache ANDROID_EMU_vulkan_ignored_handles ANDROID_EMU_has_shared_slots_host_memory_allocator ANDROID_EMU_vulkan_free_memory_sync ANDROID_EMU_vulkan_shader_float16_int8 ANDROID_EMU_vulkan_async_queue_submit ANDROID_EMU_sync_buffer_data ANDROID_EMU_read_color_buffer_dma GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_gles_max_version_2
I/OpenGLRenderer: Davey! duration=737ms; Flags=1, IntendedVsync=171246704466, Vsync=171246704466, OldestInputEvent=9223372036854775807, NewestInputEvent=0, HandleInputStart=171257497300, AnimationStart=171257574100, PerformTraversalsStart=171257666800, DrawStart=171711031000, SyncQueued=171752250500, SyncStart=171807610900, IssueDrawCommandsStart=171807860300, SwapBuffers=172005072600, FrameCompleted=172039808600, DequeueBufferDuration=820900, QueueBufferDuration=2784500, GpuCompleted=0,
I/Choreographer: Skipped 53 frames! The application may be doing too much work on its main thread.
I/OpenGLRenderer: Davey! duration=946ms; Flags=0, IntendedVsync=171263365284, Vsync=172146698582, OldestInputEvent=9223372036854775807, NewestInputEvent=0, HandleInputStart=172161042800, AnimationStart=172161115500, PerformTraversalsStart=172161649900, DrawStart=172174352400, SyncQueued=172175428100, SyncStart=172178406700, IssueDrawCommandsStart=172178473600, SwapBuffers=172180510600, FrameCompleted=172213004400, DequeueBufferDuration=780600, QueueBufferDuration=14149300, GpuCompleted=0,
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.volleydemo, PID: 3719
java.lang.ClassCastException: com.android.volley.toolbox.JsonObjectRequest cannot be cast to java.lang.CharSequence
at com.example.volleydemo.MainActivity$1.onClick(MainActivity.java:55)
at android.view.View.performClick(View.java:7448)
at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1131)
at android.view.View.performClickInternal(View.java:7425)
at android.view.View.access$3600(View.java:810)
at android.view.View$PerformClick.run(View.java:28305)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
I/Process: Sending signal. PID: 3719 SIG: 9
CodePudding user response:
Try this -
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONException;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private static final String TAG = "MainActivity";
Button Click;
TextView responseText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Click = findViewById(R.id.button);
Click.setOnClickListener(this);
responseText = findViewById(R.id.textView);
}
@Override
public void onClick(View view) {
int id = view.getId();
if (id == R.id.button) {
RequestQueue requestQueue;
requestQueue = Volley.newRequestQueue(this);
@SuppressLint("SetTextI18n") JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET,
"https://jsonplaceholder.typicode.com/todos/1",
null, response -> {
try {
responseText.setVisibility(View.VISIBLE);
Log.d(TAG, "the response is" response.getString("title"));
responseText.setText(" ID" response.getString("id") "\n Title-"
response.getString("title") "\n Completed-"
response.getString("completed") "\n User ID"
response.getString("userId") "\n");
} catch (JSONException e) {
e.printStackTrace();
}
}, error -> Log.d("myapp", "something went wrong"));
requestQueue.add(jsonObjectRequest);
}
}
}
CodePudding user response:
Remove this line response.setText((CharSequence) jsonObjectRequest);
and
add this below line in onResponse() callback method.
response.setText(result.toString());
Something like this
@Override
public void onResponse(JSONObject result) {
try {
Log.d("myapp", "the response is" response.getString("title"));
response.setText(result.toString());
} catch (JSONException e) {
e.printStackTrace();
}
}