How to redirect to the same VF page from the Constructor with parameters in Salesforce?

Biswajeet   February 9, 2017   No Comments on How to redirect to the same VF page from the Constructor with parameters in Salesforce?

Sample Code:

Apex Class:

public with sharing class SampleClass{

    public SampleClass(){
    
    }
    public PageReference doRedirect(){
        String param = ApexPages.currentPage().getParameters().get('UserId');
        if(param == null || param == ''){
            String userId = UserInfo.getUserId();
            PageReference pageRef = new PageReference('/apex/TestPage1');
            pageRef.getParameters().put('UserId',userId);
            pageRef.setRedirect(true);
            return pageRef;
        }
        else{
            return null;
        }
    }
}

VF Page:

<apex:page controller="SampleClass" action="{!doRedirect}">
	<h1>Congratulations</h1>
	This is your new Page
</apex:page>