Error with camera app

I checked the log cat in android studio and these are the errors it displays ...

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method
'android.hardware.Camera$Parameters
android.hardware.Camera.getParameters()'on a null object reference

at .easyCamView.takePicture(easyCamView.java:146)

Actual Code:

mPictureFileName = fileName;
Parameters params = mCamera.getParameters();

java.lang.RuntimeException: Fail to connect to camera service

at .easyCamView.surfaceCreated(easyCamView.java:191)

Intent openIntent = new Intent();
openIntent.setAction(Intent.ACTION_VIEW);
mContext.startActivity(openIntent);
mCamera = Camera.open();

at easyCamActivity.captureScreen(easyCamActivity.java:179)

mCameraView.takePicture(fileName);

I am able to compile the code but it crashes whenever I run it. if I can get some help that would be great.