private boolean checkInput() {
		String archiveName = getArchivePathName();
		if ((archiveName == null) || archiveName.equals("")) {
			setStatusText("Specify a valid archive file.");
			return false;
		}
		String restoreDir = restoreField.getText().trim();
		if (restoreDir == null || restoreDir.equals("") || !(new File(restoreDir)).isDirectory()) {
			setStatusText("Specify a valid project directory.");
			return false;
		}
		String restoreProjectName = projectNameField.getText().trim();
		if (restoreProjectName == null || restoreProjectName.equals("") ||
			!NamingUtilities.isValidName(restoreProjectName)) {
			setStatusText("Specify a valid project name.");
			return false;
		}

		archivePathName = archiveName;
		restoreURL = new ProjectLocator(restoreDir, restoreProjectName);

		File projFile = restoreURL.getMarkerFile();
		File projDir = restoreURL.getProjectDir();
		setStatusText("");
		if (projFile.exists() || projDir.exists()) {
			Msg.showInfo(getClass(), getComponent(), "Project Exists",
				"Cannot restore project because project named " + restoreProjectName +
					" already exists.");
			return false;
		}
		return true;
	}
Check the entry to determine if the user input is valid for restoring
a project archive.

@return boolean true if input is OK
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/archive/RestoreDialog.java