saving a json file to internal memory

Question

hey there guys and girls i have this code that should download a json object and then save it to internal memory, i keep getting stuck here

    try{
        //co         


        

Answer 1

Try this code

package com.android.test.CacheDemo;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class CachingDemoActivity extends Activity implements OnClickListener{
    private static String URL="http://bhaskar1.cntdy.mobi/punjabkesari/appdetails/sectiondetails.json";
    private static String FILE_NAME = "CachedResponse";
    private Button startAPICallButton;
    private Button retrieveFromCacheButton;

    /* view lifecycle methods*/
        @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        this.initializeComponents();
    }
    /*overriden methods*/
    public void onClick(View clickedView)
    {
        if(clickedView == this.startAPICallButton)
        {
            Toast.makeText(this, "Making the API call... Please wait", Toast.LENGTH_LONG).show();
            this.makeAPICall();
        }
        else if(clickedView == this.retrieveFromCacheButton)
        {
            Toast.makeText(this, "Retrieving data from the cache!!!", Toast.LENGTH_LONG).show();
            this.retrieveStuffFromCache();
        }
    }
    /* private methods*/
    private void initializeComponents()
    {
        this.startAPICallButton = (Button) this.findViewById(R.id.start_api_call_button);
        this.startAPICallButton.setOnClickListener(this);
        this.retrieveFromCacheButton = (Button) this.findViewById(R.id.retrieve_cache_button);
        this.retrieveFromCacheButton.setOnClickListener(this);
    }
    private void makeAPICall()
    {
        new Thread(new Runnable() 
        {
            @Override
            public void run() 
            {
                try
                {
                    //download the json onto the device.
                    URL url = new URL(CachingDemoActivity.URL);
                    URLConnection connection = url.openConnection();
                    //read the data and store it in a byte array first.
                    //dont use this code for big json file 
                    //as long as its a json and not very long, this will work just fine!!!
                    InputStream inStream = connection.getInputStream();
                    ByteArrayOutputStream byteOutStream = new ByteArrayOutputStream();
                    int readByte = 0;
                    //read the bytes one-by-one from the inputstream to the buffer.
                    while(true)
                    {
                        readByte = inStream.read();
                        if(readByte == -1)
                        {
                            break;
                        }
                        byteOutStream.write(readByte);
                    }
                    byteOutStream.flush();
                    inStream.close();
                    byteOutStream.close();
                    byte[] response = byteOutStream.toByteArray();
                    //now response byte array is the complete json in the biary form. We will save this stuff to file.
                    File cacheDir = CachingDemoActivity.this.getCacheDir();
                    File jsonFile = new File(cacheDir, FILE_NAME);
                    FileOutputStream outStream = new FileOutputStream(jsonFile);
                    //write the whole data into the file
                    for(int i = 0; i < response.length; i++)
                    {
                        outStream.write(response[i]);
                    }
                    android.util.Log.e("status - ","API call is complete!!");
                    //this should do the trick of saving all the stuff in the file with file name CachedResponse!!
                    //let see if we can retrieve the stuff!!!
                } 
                catch (Exception e) 
                {
                    e.printStackTrace();
                }
            }
        }).start();
    }

    private void retrieveStuffFromCache()
    {
        new Thread(new Runnable() 
        {
            @Override
            public void run() 
            {
                try
                {
                    File jsonFile = new File(CachingDemoActivity.this.getCacheDir(), FILE_NAME);
                    FileInputStream fInStream = new FileInputStream(jsonFile);
                    ByteArrayOutputStream byteOutStream = new ByteArrayOutputStream();
                    int readByte = 0;
                    while(true)
                    {
                        readByte = fInStream.read();
                        if(readByte == -1)
                        {
                            break;
                        }
                        byteOutStream.write(readByte);
                    }
                    fInStream.close();
                    byteOutStream.flush();
                    byteOutStream.close();
                    byte[] retrievedStringData = byteOutStream.toByteArray();
                    String originalJson = new String(retrievedStringData);
                    android.util.Log.e("json - ", originalJson);
                }
                catch(Exception ex)
                {
                    ex.printStackTrace();
                }
            }
        }).start();
    }
}