Reduce the unnecessary refresh when editing a Java file

[testforstephen]

When i'm editing a Java file, every time i typed some characters, there are a bunch of workspace commands triggered by the Project Manager for Java extension. Too many commands probably slow down the responsiveness of the language server. Need tune the refresh workflow to avoid unnecessary refresh.

Below are the command sequence triggered at each editing:
java.resolvePath - workspace/executeCommand
java.project.list - workspace/executeCommand
java.getPackageData - workspace/executeCommand
java.getPackageData - workspace/executeCommand
java.getPackageData - workspace/executeCommand
java.getPackageData - workspace/executeCommand
java.getPackageData - workspace/executeCommand
java.getPackageData - workspace/executeCommand

java.getPackageData - workspace/executeCommand
java.getPackageData - workspace/executeCommand
java.getPackageData - workspace/executeCommand
java.getPackageData - workspace/executeCommand
java.getPackageData - workspace/executeCommand
java.getPackageData - workspace/executeCommand