What is stored in the Java runtime constant pool?

The Java runtime constant pool stores the following information:

1. String constants: In Java, string constants (such as “Hello, World!”) are placed in a constant pool for reuse in the program.
2. In Java programs, every class and interface has a fully qualified name that is stored in the constant pool.
3. 运行时常量包括基本数据类型（例如int、float、double、boolean等）和它们对应的包装类（例如Integer、Float、Double、Boolean等）。
4. Symbolic references, such as class names, interface names, field names, and method names, are stored in the constant pool to resolve corresponding entities at runtime.
5. Literals, such as integers, floating point numbers, characters, and boolean values, are stored in a constant pool for reuse in the program.

It is important to note that the Java runtime constant pool is determined at compile time, which differs from the class file constant pool defined in the Java Virtual Machine specification. During the class loading process, the constant pool in the class file is loaded into the runtime constant pool and undergoes some processing and optimization.