I have a question about salesforce authentication protocols. Currently, I have an app that connects to Salesforce to read some data from a database using the rest API, and this works. The problem is that I am using the username password protocol. This is a problem because I don't want to write out my username and password in my code(java) as a variable for anyone to read. What is the best alternative OAuth 2.0 protocol to authenticate to SalesForce from a mobile app. (The user does not need to authenticate with their credentials, they only need to connect to a master account in the background of an app).
Here is the link to all the protocols available: https://help.salesforce.com/articleView?id=remoteaccess_oauth_flows.htm&language=en_US
Thanks in advance