1. JDK contains rich API (pre-prepared code modules that provide various common functions).
2. Object-oriented technology
3. Distributed - Using the API in JDK, java programs can easily realize network communication
4. Multi-threading technology
5. Dynamic
6. All data types in the java language are fixed-length and have nothing to do with the computer processor structure and operating system where the program runs.
7. Robustness--The system is responsible for allocating memory, canceling the pointer type and pointer operation
8. Security