invokestatic

invokestatic
indexbyte1
indexbyte2

Forms
invokestatic = 184 (0xb8)

Stack
..., [arg1, [arg2 ...]] ...

Description
The unsigned indexbyte1 and indexbyte2 are used to construct an index into the constant pool of the current class (§3.6), where the value of the index is (indexbyte1 << 8) | indexbyte2. The item at that index in the constant pool must have the tag CONSTANT_Methodref (§4.4.2), a reference to a class name, a method name, and the method's descriptor (§4.3.3). The named method is resolved (§5.2). The descriptor of the resolved method must be identical to the descriptor of one of the methods of the resolved class. The method must not be <init>, an instance initialization method (§3.8), or <clinit>, a class or interface initialization method (§3.8). It must be static, and therefore cannot be abstract. Finally, if the method is protected (§4.6), then it must be either a member of the current class or a member of a superclass of the current class.

The constant pool entry representing the resolved method includes a direct reference to the code for the method, an unsigned byte nargs that may be zero, and the method's modifier information (see Table 4.4, "Method access and modifier flags").

The operand stack must contain nargs words of arguments, where the number of words of arguments and the type and order of the values they represent must be consistent with the descriptor of the resolved method.

If the method is synchronized, the monitor associated with the current class is acquired.

If the method is not native, the nargs words of arguments are popped from the operand stack. A new stack frame is created for the method being invoked, and the words of arguments are made the values of its first nargs local variables, with arg1 in local variable 0, arg2 in local variable 1, and so on. The new stack frame is then made current, and the Java Virtual Machine pc is set to the opcode of the first instruction of the method to be invoked. Execution continues with the first instruction of the method.

If the method is native, the nargs words of arguments are popped from the operand stack; the code that implements the method is invoked in an implementation-dependent manner.

Linking Exceptions
During resolution of the CONSTANT_Methodref constant pool item, any of the exceptions documented in §5.2 can be thrown.

Otherwise, if the specified method exists but is an instance method, the invokestatic instruction throws an IncompatibleClass-ChangeError.

Otherwise, if the specified method is native and the code that implements the method cannot be loaded or linked, invokestatic throws an UnsatisfiedLinkError.