Access Flickr API using HttpClient

Flickr provide Flickr Services for outside developers to access Flickr photos using Flickr APIs. It's a example to query Flick using Flickr API. In order to make it simple, only ONE photo per page is request. The URL is:

FlickrQuery_url = "http://api.flickr.com/services/rest/?method=flickr.photos.search&per_page=1&nojsoncallback=1&format=json&tags=<search>&api_key=<API KEY>

where:
<search> is the search word, (don't insert SPACE in this exercise!)
<API KEY> is your API Key



In order to access Flickr API, you have to apply your own API key at www.flickr.com/services/apps/create/apply/?.

The example access the API via HttpClient, using HttpGet() method. The result is in JSON format. It will be parse in next exercise, "Parse JSON returned from Flickr Services".

package com.exercise.AndroidFlickr;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;

import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class AndroidFlickrActivity extends Activity {

/*
* FlickrQuery = FlickrQuery_url
* + FlickrQuery_per_page
* + FlickrQuery_nojsoncallback
* + FlickrQuery_format
* + FlickrQuery_tag + q
* + FlickrQuery_key + FlickrApiKey
*/

String FlickrQuery_url = "http://api.flickr.com/services/rest/?method=flickr.photos.search";
String FlickrQuery_per_page = "&per_page=1";
String FlickrQuery_nojsoncallback = "&nojsoncallback=1";
String FlickrQuery_format = "&format=json";
String FlickrQuery_tag = "&tags=";
String FlickrQuery_key = "&api_key=";

// Apply your Flickr API:
// www.flickr.com/services/apps/create/apply/?
String FlickrApiKey = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";

EditText searchText;
 Button searchButton;
 TextView textQueryResult;

 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.main);
  
     searchText = (EditText)findViewById(R.id.searchtext);
     searchButton = (Button)findViewById(R.id.searchbutton);
     textQueryResult = (TextView)findViewById(R.id.queryresult);
  
     searchButton.setOnClickListener(searchButtonOnClickListener);
 }

 private Button.OnClickListener searchButtonOnClickListener
 = new Button.OnClickListener(){

public void onClick(View arg0) {
 // TODO Auto-generated method stub
 String searchQ = searchText.getText().toString();
 String searchResult = QueryFlickr(searchQ);
 textQueryResult.setText(searchResult);
}};

 private String QueryFlickr(String q){

  String qResult = null;

  String qString =
    FlickrQuery_url
    + FlickrQuery_per_page
    + FlickrQuery_nojsoncallback
    + FlickrQuery_format
    + FlickrQuery_tag + q
    + FlickrQuery_key + FlickrApiKey;

  HttpClient httpClient = new DefaultHttpClient();
     HttpGet httpGet = new HttpGet(qString);
  
     try {
 HttpEntity httpEntity = httpClient.execute(httpGet).getEntity();

 if (httpEntity != null){
  InputStream inputStream = httpEntity.getContent();
  Reader in = new InputStreamReader(inputStream);
  BufferedReader bufferedreader = new BufferedReader(in);
  StringBuilder stringBuilder = new StringBuilder();

  String stringReadLine = null;

  while ((stringReadLine = bufferedreader.readLine()) != null) {
   stringBuilder.append(stringReadLine + "\n");
   }

  qResult = stringBuilder.toString();

 }

} catch (ClientProtocolException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
} catch (IOException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
}
  
     return qResult;
 }
}

layout, main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 >
<TextView
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:text="@string/hello"
 />
<EditText
 android:id="@+id/searchtext"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 />
<Button
 android:id="@+id/searchbutton"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:text="Search"
 />
<TextView
 android:id="@+id/queryresult"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 />
</LinearLayout>

Modify AndroidManifest.xml to grant permission of "android.permission.INTERNET".

Download the files.

next article:
- Parse JSON returned from Flickr Services