Android應用啟動另一個應用

已知包名和應用入口Activity

包名:org.ww
應用入口:Activity:org.ww.TestActivity

Intent intent = new Intent();   
intent.setComponent(new ComponentName("org.ww","org.ww.TestActivity"));   
intent.setAction(Intent.ACTION_VIEW);   
startActivity(intent);

只知包名
包名:org.ww
?

// 使用packageManager通過應用包名，得到intent
PackageManager packageManager = this.getPackageManager();
Intent intentPackage = packageManager.getLaunchIntentForPackage("org.ww");
startActivity(intentPackage);