android中判断某个应用是否存在

public boolean checkApk(String packageName) {
if (packageName == null || "".equals(packageName))
return false;
try {
ApplicationInfo info = getPackageManager().getApplicationInfo(
packageName, PackageManager.GET_UNINSTALLED_PACKAGES);
return true;
} catch (NameNotFoundException e) {
return false;
}
}