Use Intent Categories
Description
You can group your activities into categories by
using the <category> element in the intent filter.
Example
AndroidManifest.xml file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.java2s.Intents"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="14" />
<uses-permission android:name="android.permission.CALL_PHONE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:label="@string/app_name"
android:name=".IntentsActivity" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".MyBrowserActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<action android:name="com.java2s.MyBrowser" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="com.java2s.Apps" />
<data android:scheme="http" />
</intent-filter>
</activity>
</application>
</manifest>
The following code will directly invoke the MyBrowerActivity activity:
Intent i = new Intent(android.content.Intent.ACTION_VIEW, Uri.parse ("http://www.java2s.com"));
i.addCategory("com.java2s.Apps");
startActivity(Intent.createChooser(i, "Open URL using..."));
If you omit the addCategory() statement,
the preceding code will still invoke
the MyBrowerActivity activity
because it will still match the default category android.intent.category.DEFAULT.
For the following code it does not match the category defined in the intent filter, therefore no activity will be launched:
Note
The following code references category com.java2s.OtherApps and it does not match any category in the intent filter, so a run-time exception will be raised if you don't use the createChoose() method of the Intent class.
Intent i = new Intent(android.content.Intent.ACTION_VIEW,Uri.parse ("http://www.java2s.com"));
//i.addCategory("com.java2s.Apps");
//this category does not match any in the intent-filter
i.addCategory("com.java2s.OtherApps");
startActivity(Intent.createChooser(i, "Open URL using..."));