È necessario registrare un'app a http://dev.twitter.com/apps/ per ottenere una chiave utente e un segreto se si desidera utilizzare twitter4j.
La mia app pubblica semplicemente un tweet con un'immagine e speravo di trovare una semplice funzione di tweet ma ho trovato invece un labirinto di dettagli di autenticazione e problemi di thread di codice.
Per semplificare il tweet con un'immagine, ho incapsulato twitter4j all'interno di un file JAR wrapper che gestisce tutti i problemi di autenticazione e di threading. Richiede solo poche righe di codice (almeno 3) per funzionare. Il file JAR si chiama MSTwitter.jar.
MSTwitter.jar contiene tre file uno dei quali è MSTwitter. In cima a questo file ci sono commenti che spiegano come usare il JAR. Essi sono ripetute qui:
To use MSTwitter.jar:
-Project setup:
-Create a twitter app on https://dev.twitter.com/apps/ to get:
-CONSUMER_KEY a public key(string) used to authenticate your app with Twitter.com
-CONSUMER_SECRET a private key(string) used to authenticate your app with Twitter.com
You don't need any thing else so authorization url etc are not important for this process
-Put twitter4j-core-3.0.2.jar and MSTwitter.jar files in your project's libs directory:
-You can download twitter4j from from http://twitter4j.org
-Register the jars in your project build path:
Project->Properties->Java Build Path->Libraries->Add Jar
->select the jar files you just added to your project's libs directory.
-Make AndroidManifest.xml modifications
-Add <uses-permission android:name="android.permission.INTERNET" /> inside manifest section (<manifest>here</manifest>)
-Add <uses-permission android:name="com.mindspiker.mstwitter.MSTwitterService" /> inside manifest section
-Add <uses-permission android:name="android.permission.BROADCAST_STICKY" /> inside manifest section
-Add <activity android:name="com.mindspiker.mstwitter.MSTwitterAuthorizer" /> inside application section.
-Add <service android:name="com.mindspiker.mstwitter.MSTwitterService" /> inside application section.
-Code to add to you calling activity
-Define a module MSTwitter variable.
-In onCreate() allocate a module level MSTwitter variable
ex: mMTwitter = new MSTWitter(args);]
-Add code to catch response from MSTwitterAuthorizer in your activity's onActivityResult()
ex:@Override protected void onActivityResult(int requestCode, int resultCode, Intent data){ mMSTwitter.onCallingActivityResult(requestCode, resultCode, data); }
-Call startTweet(String text, String imagePath) on your MSTwitter object instance.
if you image is held in memory and not saved to disk call
MSTwitter.putBitmapInDiskCache() to save to a temporary file on disk.
-(Optional) Add a MSTwitterResultReceiver to catch MSTwitter events which are
fired at various stages of the process.
MSTwitterResultReceiver events:
-MSTWEET_STATUS_AUTHORIZING the app is not authorized and the authorization process is starting.
-MSTWEET_STATUS_STARTING the app is authorized and sending the tweet text and image is starting.
-MSTWEET_STATUS_FINSIHED_SUCCCESS the tweet is done and was successful.
-MSTWEET_STATUS_FINSIHED_FAILED the tweet is done and failed to complete.
Notes:
-If your project compiles but crashes when any twwiter4j object is instantiated a possible cause may be trying to add the jars as external jars instead of the suggested method above. If your libraries directory already exists but is called 'lib', change the name to 'libs'. Sounds crazy I know, but works in some situations.
-To prevent large images from being passed around between intents images should be cached to disk and retrieved when used. Only the file name is passed between intents.
-To perform tasks on a separate thread that passes information to and from activities, which could be destroyed at any time (phone call, screen orientation change, etc.), a method using intent services to perform the work and sticky broadcasts to pass the data was employed. For more on this method and why it was used check out: http://stackoverflow.com/questions/1111980/how-to-handle-screen-orientation-change-when-progress-dialog-and-background-thre/8074278#8074278
I file che seguono sono da un progetto di esempio che i messaggi un tweet con una foto.
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.imagetweettester" android:versionCode="1" android:versionName="1.0" >
<uses-sdk android:minSdkVersion="8"android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="com.mindspiker.mstwitter.MSTwitterService" />
<uses-permission android:name="android.permission.BROADCAST_STICKY" />
<application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" >
<activity android:name="com.example.imagetweettester.MainActivity" android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="com.mindspiker.mstwitter.MSTwitterAuthorizer" />
<service android:name="com.mindspiker.mstwitter.MSTwitterService" />
</application>
</manifest>
MainActivity.java
package com.example.imagetweettester;
import java.text.SimpleDateFormat;
import java.util.Date;
import com.mindspiker.mstwitter.MSTwitter;
import com.mindspiker.mstwitter.MSTwitter.MSTwitterResultReceiver;
import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
/** Consumer Key generated when you registered your app at https://dev.twitter.com/apps/ */
public static final String CONSUMER_KEY = "yourConsumerKeyHere";
/** Consumer Secret generated when you registered your app at https://dev.twitter.com/apps/ */
public static final String CONSUMER_SECRET = "yourConsumerSecretHere";
/** module level variables used in different parts of this module */
private MSTwitter mMSTwitter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// setup button to call local tweet() function
Button tweetButton = (Button) findViewById(R.id.button1);
tweetButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
tweet();
}
});
// make a MSTwitter event handler to receive tweet send events
MSTwitterResultReceiver myMSTReceiver = new MSTwitterResultReceiver() {
@Override
public void onRecieve(int tweetLifeCycleEvent, String tweetMessage) {
handleTweetMessage(tweetLifeCycleEvent, tweetMessage);
}
};
// create module level MSTwitter object.
// This object can be destroyed and recreated without interrupting the send tweet process.
// So no need to save and pass back in savedInstanceState bundle.
mMSTwitter = new MSTwitter(this, CONSUMER_KEY, CONSUMER_SECRET, myMSTReceiver);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data){
//This MUST MUST be done for authorization to work. If your get a MSTWEET_STATUS_AUTHORIZING
// message and nothing else it is most likely because this is not being done.
mMSTwitter.onCallingActivityResult(requestCode, resultCode, data);
}
/**
* Send tweet using MSTwitter object created in onCreate()
*/
private void tweet() {
// assemble data
// get text from layout control
EditText tweetEditText = (EditText) findViewById(R.id.editText1);
String textToTweet = tweetEditText.getText().toString();
// get image from resource
Bitmap imageToTweet = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
// use MSTwitter function to save image to file because startTweet() takes an image path
// this is done to avoid passing large image files between intents which is not android best practices
String tweetImagePath = MSTwitter.putBitmapInDiskCache(this, imageToTweet);
// start the tweet
mMSTwitter.startTweet(textToTweet, tweetImagePath);
}
@SuppressLint("SimpleDateFormat")
private void handleTweetMessage(int event, String message) {
String note = "";
switch (event) {
case MSTwitter.MSTWEET_STATUS_AUTHORIZING:
note = "Authorizing app with twitter.com";
break;
case MSTwitter.MSTWEET_STATUS_STARTING:
note = "Tweet data send started";
break;
case MSTwitter.MSTWEET_STATUS_FINSIHED_SUCCCESS:
note = "Tweet sent successfully";
break;
case MSTwitter.MSTWEET_STATUS_FINSIHED_FAILED:
note = "Tweet failed:" + message;
break;
}
// add note to results TextView
SimpleDateFormat timeFmt = new SimpleDateFormat("h:mm:ss.S");
String timeS = timeFmt.format(new Date());
TextView resultsTV = (TextView) findViewById(R.id.resultsTextView);
resultsTV.setText(resultsTV.getText() + "\n[Message received at " + timeS +"]\n" + note);
}
}
activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical" tools:context=".MainActivity" >
<Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:text="Start Tweet" />
<TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Text to tweet:" />
<EditText android:id="@+id/editText1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:ems="10" android:text="Test tweet text" >
<requestFocus />
</EditText>
<ImageView android:id="@+id/imageView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/ic_launcher" />
<TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Results:" />
<TextView android:id="@+id/resultsTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="" />
</LinearLayout>
qualsiasi cosa si prova? –