- Stackoverflow
Stackoverflow.com is probably the most popular website in the programming world. There are millions of good questions and answers. Learning an API or programming language often relies on code samples, stackoverflow has a lot of code snippets.
Another good thing about stackoverflow is that it is social. You can look at questions under certain tags like "java" and "regex" and you can see what questions are the most frequently asked and upvoted. This can be a good resource for learning and for writing Java blogging hot topics.
Website URL: http://stackoverflow.com/
- DZone
DZone is an interesting site and many developers share their blog posts. The categories are average, so you may not know what to read next on this site.
Website URL: http://www.dzone.com
- LeetCode
If the interview question is java, like "what does an array in memory look like in java", then the answer can be obtained from many java tutorials. However, if the question is something like "How to convert a sorted array to a balanced tree", this can be found in LeetCode.
leetcode is a social platform for preparing IT technical interviews and contains a series of algorithm related questions. You can check that your code is correct by providing data of different sizes. To be successful in a technical interview, they think it's mainly about repeating these three important steps: code → read → discuss.
Website URL: http://leetcode.com/
- Java SE Technical Documentation
This site contains all the documentation you will need to use Java SE's APIs. Even advanced Java developers are sure you will find something useful here. For example, you can read some tutorials on "Basic Java Classes", "Deployment", etc.
Website URL: http://docs.oracle.com/javase/
- Github
You can host your projects for free on Github, but you may not know that it is an excellent resource for learning popular Java libraries and frameworks. For example, if you want to learn the Spring MVC framework, you can search and find some open source projects. Frameworks can be learned quickly by example, especially if you already have some experience with similar frameworks.
Website URL: https://github.com/
- Coursera
This is the best site for video learning. Many good computer science programs can be found from well-known professors at top schools. Some of them are even inventors in the field of computer science.
Website URL: https://www.coursera.org/
- The Java World
website contains a large number of Java tutorials on various topics. Many articles are well written and have illustrated pictures/graphics. It can be used as a deep learning book.
Website URL: http://www.javaworld.com/