Tuesday, February 14, 2017

android - Volley setup Network and Cache example

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/coordinator_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#8cd5ff"
    >
    <Button
        android:id="@+id/btn_do"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Request String From URL"
        android:layout_margin="25dp"
        android:layout_gravity="top|center_horizontal"
        />
    <TextView
        android:id="@+id/tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_anchor="@id/btn_do"
        app:layout_anchorGravity="bottom"
        android:layout_gravity="bottom|center_horizontal"
        android:layout_margin="15dp"
        android:textSize="18sp"
        android:fontFamily="sans-serif-condensed"
        />
</android.support.design.widget.CoordinatorLayout>
MainActivity.java

package com.cfsuman.me.androidcodesnippets;

import android.app.Activity;
import android.content.Context;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.method.ScrollingMovementMethod;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import com.android.volley.Cache;
import com.android.volley.Network;
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.BasicNetwork;
import com.android.volley.toolbox.DiskBasedCache;
import com.android.volley.toolbox.HurlStack;
import com.android.volley.toolbox.StringRequest;


public class MainActivity extends AppCompatActivity {
    private Context mContext;
    private Activity mActivity;

    private CoordinatorLayout mCLayout;
    private Button mButtonDo;
    private TextView mTextView;
    private String mUrlString = "https://android--examples.blogspot.com";
    private RequestQueue mRequestQueue;


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

        // Get the application context
        mContext = getApplicationContext();
        mActivity = MainActivity.this;

        // Get the widget reference from XML layout
        mCLayout = (CoordinatorLayout) findViewById(R.id.coordinator_layout);
        mButtonDo = (Button) findViewById(R.id.btn_do);
        mTextView = (TextView) findViewById(R.id.tv);

        // Make the text view scrollable
        mTextView.setMovementMethod(new ScrollingMovementMethod());

        // Set a click listener for button widget
        mButtonDo.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                // Empty the TextView
                mTextView.setText("");

                // Instantiate the cache
                Cache cache = new DiskBasedCache(getCacheDir(),1024*1024*5); // 5MB cache size

                // Setup the network to use HttpURLConnection as the HTTP client
                Network network = new BasicNetwork(new HurlStack());

                // Instantiate the RequestQueue with cache and network
                mRequestQueue = new RequestQueue(cache,network);

                // Start the RequestQueue
                mRequestQueue.start();

                // Initialize a new StringRequest
                StringRequest stringRequest = new StringRequest(
                        Request.Method.GET,
                        mUrlString,
                        new Response.Listener<String>() {
                            @Override
                            public void onResponse(String response) {
                                // Do something with response string
                                mTextView.setText(response);
                            }
                        },
                        new Response.ErrorListener() {
                            @Override
                            public void onErrorResponse(VolleyError error) {
                                // Do something when get error
                                Snackbar.make(mCLayout,"Error...",Snackbar.LENGTH_LONG).show();
                            }
                        }
                );

                // Add StringRequest to the RequestQueue
                mRequestQueue.add(stringRequest);
            }
        });
    }
}
build.gradle(app) dependencies

compile 'com.android.volley:volley:1.0.0'