I am basically a PHP developer with almost 3 years of experience. But I would like to change my career completely from PHP to Java web development. In PHP career, the seems very low compared to Java. So I'm planning to shift to Java Web development and learn Spring Framework. How long will it take to learn core Java, JSP and Servlets to start learning Spring Framework? I have basic understanding of OOP concepts. Also, I would like to know is it too late to make a career shift. I'm 23 yrs old with a Bachelors in Computer Science.
I feel so sad about my very low pay as a PHP developer I would like to learn Spring and Hibernate. What are the steps I need to follow to make sure I get the complete knowledge to develop an application using Spring?
Secondly: you're never too old to learn a new skill. In fact, if you aren't capable of learning new skills at any age (I'm more than twice your age, by the way) you're in the wrong business. So learning Java isn't any sort of "career change"; it's just learning a new language and skill.
No one can tell you how long it will take you to "learn Java". Everyone learns at their own pace. Besides, at what point do you declare something "learned"? No one never know everything about anything. Life is a continual learning process.