How to use android.content.pm

 final PackageManager pm = getApplicationContext().getPackageManager();
ApplicationInfo ai;
try {
  ai = pm.getApplicationInfo( this.getPackageName(), 0);
} catch (final NameNotFoundException e) {
  ai = null;
}
final String applicationName = (String) (ai != null ? pm.getApplicationLabel(ai) : "(unknown)");

 private boolean isPackageInstalled(String packagename, PackageManager packageManager) {
  try {
    packageManager.getPackageInfo(packagename, PackageManager.GET_ACTIVITIES);
    return true;
  } catch (NameNotFoundException e) {
    return false;
  }
}

 @Override
 public void run() {
  callbackInfo.callback.onProgressChanged(sessionId, progress);
 }
});

public static PackageInfo getPackageInfo(Context context, String pckName) {
  try {
    return context.getPackageManager()
        .getPackageInfo(pckName, 0);
  } catch (PackageManager.NameNotFoundException e) {
    e.printStackTrace();
  }
  return null;
}

  public boolean supportsMultitouch (Context activity) {
    return activity.getPackageManager().hasSystemFeature("android.hardware.touchscreen.multitouch");
  }
}

private static PackageInfo createPackageInfoWithPackageName(String packageName) {
 PackageInfo packageInfo = new PackageInfo();
 packageInfo.packageName = packageName;
 packageInfo.applicationInfo = new ApplicationInfo();
 packageInfo.applicationInfo.packageName = packageName;
 packageInfo.applicationInfo.name = TEST_PACKAGE_LABEL;
 return packageInfo;
}

private static ResolveInfo buildResolveInfo(ComponentInfo componentInfo) {
 ResolveInfo resolveInfo = new ResolveInfo();
 resolveInfo.resolvePackageName = componentInfo.applicationInfo.packageName;
 resolveInfo.labelRes = componentInfo.labelRes;
 resolveInfo.icon = componentInfo.icon;
 resolveInfo.nonLocalizedLabel = componentInfo.nonLocalizedLabel;
 return resolveInfo;
}

private static PackageInfo newPackageInfo(String packageName, Signature... signatures) {
 PackageInfo firstPackageInfo = new PackageInfo();
 firstPackageInfo.packageName = packageName;
 firstPackageInfo.signatures = signatures;
 return firstPackageInfo;
}

private static PackageInstaller.SessionParams createSessionParams(String appPackageName) {
 PackageInstaller.SessionParams params =
   new PackageInstaller.SessionParams(PackageInstaller.SessionParams.MODE_FULL_INSTALL);
 params.setAppPackageName(appPackageName);
 return params;
}

private static PermissionInfo createCopyPermissionInfo(PermissionInfo src, int flags) {
 PermissionInfo matchedPermission = new PermissionInfo(src);
 if ((flags & GET_META_DATA) != GET_META_DATA) {
  matchedPermission.metaData = null;
 }
 return matchedPermission;
}

 @Override
 public void run() {
  callbackInfo.callback.onFinished(sessionId, false);
 }
});

 @Override
 public void run() {
  callbackInfo.callback.onCreated(sessionInfo.sessionId);
 }
});

 public String[] setPackagesSuspended(String[] packageNames, boolean suspended, PersistableBundle appExtras, PersistableBundle launcherExtras, String dialogMessage) {
  return packageManager.setPackagesSuspended(
    packageNames, suspended, appExtras, launcherExtras, dialogMessage);
 }
}

import android.content.pm.PackageManager;
public boolean isPackageExisted(String targetPackage){
 PackageManager pm=getPackageManager();
 try {
  PackageInfo info=pm.getPackageInfo(targetPackage,PackageManager.GET_META_DATA);
 } catch (PackageManager.NameNotFoundException e) {
  return false;
 }  
 return true;
}

  public boolean supportsMultitouch (Context activity) {
    return activity.getPackageManager().hasSystemFeature("android.hardware.touchscreen.multitouch");
  }
}

 private static PackageInstaller.SessionParams createSessionParams(String appPackageName) {
  PackageInstaller.SessionParams params = new PackageInstaller.SessionParams(PackageInstaller.SessionParams.MODE_FULL_INSTALL);
  params.setAppPackageName(appPackageName);
  return params;
 }
}

 @Override
 public void run() {
  callbackInfo.callback.onFinished(sessionId, success);
 }
});

 PackageManager manager = this.getPackageManager();
PackageInfo info = manager.getPackageInfo(this.getPackageName(), 0);
Toast.makeText(this,
   "PackageName = " + info.packageName + "\nVersionCode = "
    + info.versionCode + "\nVersionName = "
    + info.versionName + "\nPermissions = " + info.permissions, Toast.LENGTH_SHORT).show();

 String foregroundTaskPackageName = foregroundTaskInfo .topActivity.getPackageName();
PackageManager pm = AppService.this.getPackageManager();
PackageInfo foregroundAppPackageInfo = pm.getPackageInfo(foregroundTaskPackageName, 0);
String foregroundTaskAppName = foregroundAppPackageInfo.applicationInfo.loadLabel(pm).toString();

private int getResourceId(String packageName) {
 PackageInfo packageInfo;
 try {
  packageInfo = context.getPackageManager().getPackageInfo(packageName, /*flags=*/ 0);
 } catch (NameNotFoundException e) {
  return 0;
 }
 return packageInfo.applicationInfo.icon;
}