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Articles on Trending Technologies
Technical articles with clear explanations and examples
How can we update an existing JSON data using javax.json API in Java?
The JsonBuilderFactory interface is a factory to create JsonObjectBuilder instance and JsonObjectBuilder is a builder for creating JsonObject models from scratch. This interface initializes an empty JSON object model and provides methods to add name/value pairs to the object model and to return the resulting object. We can create a JsonObjectBuilder instance that can be used to build JsonObject using the createObjectBuilder() method.SyntaxJsonObjectBuilder createObjectBuilder()In the below example, We can update an existing JSON data with newly added data.Exampleimport java.io.*; import javax.json.*; public class UpdateExistingJsonTest { public static void main(String[] args) throws Exception { String jsonString = "{\"id\":\"115\", \"name\":\"Raja\", \"address\":[{\"area\":\"Madhapur\", \"city\":\"Hyderabad\"}]}"; ...
Read MoreJSON Schema Support using Jackson in Java?
JSON Schema is a specification for JSON based format for defining the structure of JSON data. The JsonSchema class can provide a contract for what JSON data is required for a given application and how to interact with it. The JsonSchema can define validation, documentation, hyperlink navigation, and interaction control of JSON data. We can generate the JSON schema using the generateSchema() method of JsonSchemaGenerator, this class wraps the JSON schema generation functionality.Syntaxpublic JsonSchema generateSchema(Class type) throws com.fasterxml.jackson.databind.JsonMappingExceptionExampleimport com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.module.jsonSchema.JsonSchema; import com.fasterxml.jackson.module.jsonSchema.JsonSchemaGenerator; import java.util.List; public class JSONSchemaTest { public static void main(String[] args) throws JsonProcessingException { ...
Read MoreHow to check if a bluetooth device is connected with Android device?
This example demonstrates how do I check if a Bluetooth device is connected with android device.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. Step 3 − Add the following code to src/MainActivity.javaimport android.bluetooth.BluetoothDevice; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.os.Bundle; import android.widget.Toast; import androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); ...
Read MoreHow to get free size of internal/external memory in Android App?
This example demonstrates how do I get the free size of internal/external memory in android app.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. Step 3 − Add the following code to src/MainActivity.javaimport android.os.Bundle; import android.os.Environment; import android.os.StatFs; import android.util.Log; import android.widget.TextView; import androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity { TextView textView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); ...
Read MoreHow to convert a Base64 string into a Bitmap image in Android app?
This example demonstrates how to do I in android.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. Step 3 − Add the following code to src/MainActivity.javaimport android.annotation.SuppressLint; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.Bundle; import android.util.Base64; import android.widget.ImageView; import java.io.ByteArrayOutputStream; import androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity { ImageView imageView; @SuppressLint("WrongThread") @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); ...
Read MoreHow to play background music in Android app?
This example demonstrates how do I play background music in android.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. Step 3 − Add the following code to src/MainActivity.javaimport android.content.Intent; import android.os.Bundle; import android.view.View; import androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public void PlayBackgroundSound(View view) { Intent intent ...
Read MoreHow to convert Java array or ArrayList to JsonArray using Gson in Java?
The Java Arrays are objects which store multiple variables of the same type, it holds primitive types and object references and an ArrayList can represent a resizable list of objects. We can add, remove, find, sort and replace elements using the list. A JsonArray can parse text from a string to produce a vector-like object. We can convert an array or ArrayList to JsonArray using the toJsonTree().getAsJsonArray() method of Gson class.Syntaxpublic JsonElement toJsonTree(java.lang.Object src)Exampleimport com.google.gson.*; import java.util.*; public class JavaArrayToJsonArrayTest { public static void main(String args[]) { String[][] strArray = {{"elem1-1", "elem1-2"}, {"elem2-1", "elem2-2"}}; ArrayList arrayList = ...
Read MoreHow to play videos in Android TextureView?
This example demonstrates how do I play videos in Android TextureView.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. Step 3 − Create an asset folder and copy-paste the video into the asset folder.Step 4 − Add the following code to src/MainActivity.javaimport androidx.appcompat.app.AppCompatActivity; import android.content.res.AssetFileDescriptor; import android.graphics.SurfaceTexture; import android.media.MediaPlayer; import android.os.Build; import android.os.Bundle; import android.view.Surface; import android.view.TextureView; import java.io.IOException; public class MainActivity extends AppCompatActivity implements TextureView.SurfaceTextureListener, MediaPlayer.OnVideoSizeChangedListener { TextureView textureView; private ...
Read MoreHow to check available space on Android Device?
This example demonstrates how do I check available space on an android device.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. Step 3 − Add the following code to src/MainActivity.javaimport androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.os.Environment; import android.os.StatFs; import android.text.format.Formatter; import android.util.Log; import android.widget.TextView; import java.io.File; public class MainActivity extends AppCompatActivity { TextView textView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); ...
Read MoreHow to create different graphs in Android App?
This example demonstrates how to do I in android.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following dependency in the build.gradle (Module: app)implementation 'com.jjoe64:graphview:4.2.1'Step 3 − Add the following code to res/layout/activity_main.xml. Step 4 − Add the following code to src/MainActivity.javaimport androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import com.jjoe64.graphview.GraphView; import com.jjoe64.graphview.series.DataPoint; import com.jjoe64.graphview.series.LineGraphSeries; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); ...
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