在 javap -verbose 之后，缺少一个常量池项

Question

我创建了一个Java class 命名为JVMClassTest 然后编译。之后我运行"javap -verbose JVMClassTest".常量池的#4在哪里

    public class JVMClassTest {
        private int i = 0;
        private static String s = "tString";
        private final double d = 1.2d;

        public JVMClassTest() {

        }

        public int getI() {
            return i;
        }

        public static String getS() {
            return s;
        }

        public double getD() {
            return d;
        }
    }

下面是结果截图

Answer 1

根据 JVM specification on the classfile format:

The CONSTANT_Long_info and CONSTANT_Double_info represent 8-byte numeric (long and double) constants:

...

All 8-byte constants take up two entries in the constant_pool table of the class file. If a CONSTANT_Long_info or CONSTANT_Double_info structure is the item in the constant_pool table at index n, then the next usable item in the pool is located at index n+2.

在 javap -verbose 之后，缺少一个常量池项

After javap -verbose, one constant pool item is missing

java

jvm