Android Open Source - SpringForAndroidDemo Main Activity

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License

The source code is released under:

Apache License

Java Source Code

package com.sample.springforandroiddemo;
//from  w  w  w.  j av  a2s .c o m
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.client.RestTemplate;

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;


public class MainActivity extends ActionBarActivity {
  
  // ---------------------------------------------------------------------------
  // Class Constants
  
  private static final String KEY_GREETING =  "GREETING";
  
  // ---------------------------------------------------------------------------
  // Member Variables
  
  private Greeting greeting;
  private TextView greetingIdText ;
    private TextView greetingContentText ;

  // ---------------------------------------------------------------------------
    // Class Overrides
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        // Reference the UI Elements
        greetingIdText     = (TextView) findViewById(R.id.id_value);
        greetingContentText = (TextView) findViewById(R.id.content_value);
        
        // If savedInstanceState is not null
        if(savedInstanceState != null){
          // Get the Greeting from the Bundle
          greeting = savedInstanceState.getParcelable(KEY_GREETING);
            
          // Update the UI
          updateView(greeting);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_refresh) {
          
          // Make a new Request to get the Greeting
          new HttpRequestTask().execute();
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
  public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putParcelable(KEY_GREETING, greeting);
  }

  // ---------------------------------------------------------------------------
    // Public / Private Helpers
    
    /**
     * Updates the View Elements
     * @param greeting - the greeting retrieved from refreshing the URL
     */
    private void updateView(Greeting greeting){
      
      // If the greeting is not null
      if(greeting != null){
        
        // Update the UI
        greetingIdText.setText(greeting.getId());
          greetingContentText.setText(greeting.getContent());
      }
    }

  // ---------------------------------------------------------------------------
    // Background Tasks
    
  private class HttpRequestTask extends AsyncTask<Void, Void, Greeting> {
        @Override
        protected Greeting doInBackground(Void... params) {
            try {
                final String url = "http://rest-service.guides.spring.io/greeting";
                RestTemplate restTemplate = new RestTemplate();
                restTemplate.getMessageConverters().add(new MappingJackson2HttpMessageConverter());
                greeting = restTemplate.getForObject(url, Greeting.class);
                return greeting;
            } catch (Exception e) {
                Log.e("MainActivity", e.getMessage(), e);
            }

            return null;
        }

        @Override
        protected void onPostExecute(Greeting greeting) {
            // Update the view
            updateView(greeting);
        }
    }
    
}

Java Source Code List

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