com.fitbur.bytebuddy.implementation.bytecode.constant.ClassConstant Maven / Gradle / Ivy
package com.fitbur.bytebuddy.implementation.bytecode.constant;
import com.fitbur.bytebuddy.description.type.TypeDescription;
import com.fitbur.bytebuddy.implementation.Implementation;
import com.fitbur.bytebuddy.implementation.bytecode.StackManipulation;
import com.fitbur.bytebuddy.implementation.bytecode.StackSize;
import com.fitbur.bytebuddy.jar.asm.MethodVisitor;
import com.fitbur.bytebuddy.jar.asm.Opcodes;
import com.fitbur.bytebuddy.jar.asm.Type;
/**
* Represents a constant representing any loaded Java {@link java.lang.Class}.
*/
public enum ClassConstant implements StackManipulation {
/**
* The {@code void} type.
*/
VOID(Void.class),
/**
* The {@code boolean} type.
*/
BOOLEAN(Boolean.class),
/**
* The {@code byte} type.
*/
BYTE(Byte.class),
/**
* The {@code short} type.
*/
SHORT(Short.class),
/**
* The {@code char} type.
*/
CHARACTER(Character.class),
/**
* The {@code int} type.
*/
INTEGER(Integer.class),
/**
* The {@code long} type.
*/
LONG(Long.class),
/**
* The {@code float} type.
*/
FLOAT(Float.class),
/**
* The {@code double} type.
*/
DOUBLE(Double.class);
/**
* The size of a {@link java.lang.Class} on the operand stack.
*/
private static final Size SIZE = StackSize.SINGLE.toIncreasingSize();
/**
* The field name that stores a reference to the primitive type representation.
*/
private static final String PRIMITIVE_TYPE_FIELD = "TYPE";
/**
* The descriptor of the {@link java.lang.Class} type.
*/
private static final String CLASS_TYPE_INTERNAL_NAME = "Ljava/lang/Class;";
/**
* The internal name of the type owning the field.
*/
private final String fieldOwnerInternalName;
/**
* Creates a new class constant for a primitive type.
*
* @param type The primitive type to represent.
*/
ClassConstant(Class type) {
fieldOwnerInternalName = Type.getInternalName(type);
}
/**
* Returns a stack manipulation that loads a {@link java.lang.Class} type onto the operand stack which
* represents the given type.
*
* @param typeDescription The type to load onto the operand stack.
* @return The corresponding stack manipulation.
*/
public static StackManipulation of(TypeDescription typeDescription) {
if (typeDescription.represents(void.class)) {
return VOID;
} else if (typeDescription.represents(boolean.class)) {
return BOOLEAN;
} else if (typeDescription.represents(byte.class)) {
return BYTE;
} else if (typeDescription.represents(short.class)) {
return SHORT;
} else if (typeDescription.represents(char.class)) {
return CHARACTER;
} else if (typeDescription.represents(int.class)) {
return INTEGER;
} else if (typeDescription.represents(long.class)) {
return LONG;
} else if (typeDescription.represents(float.class)) {
return FLOAT;
} else if (typeDescription.represents(double.class)) {
return DOUBLE;
} else {
return new ForReferenceType(typeDescription);
}
}
@Override
public boolean isValid() {
return true;
}
@Override
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
methodVisitor.visitFieldInsn(Opcodes.GETSTATIC, fieldOwnerInternalName, PRIMITIVE_TYPE_FIELD, CLASS_TYPE_INTERNAL_NAME);
return SIZE;
}
@Override
public String toString() {
return "ClassConstant." + name();
}
/**
* A class constant for a non-primitive {@link java.lang.Class}.
*/
protected static class ForReferenceType implements StackManipulation {
/**
* The type which should be loaded onto the operand stack as a class value.
*/
private final TypeDescription typeDescription;
/**
* Creates a stack manipulation that represents loading a class constant onto the stack.
*
* @param typeDescription A description of the class to load onto the stack.
*/
protected ForReferenceType(TypeDescription typeDescription) {
this.typeDescription = typeDescription;
}
@Override
public boolean isValid() {
return true;
}
@Override
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
methodVisitor.visitLdcInsn(Type.getType(typeDescription.getDescriptor()));
return SIZE;
}
@Override
public boolean equals(Object other) {
return this == other || !(other == null || getClass() != other.getClass())
&& typeDescription.equals(((ForReferenceType) other).typeDescription);
}
@Override
public int hashCode() {
return typeDescription.hashCode();
}
@Override
public String toString() {
return "ClassConstant.ForReferenceType{typeDescription=" + typeDescription + '}';
}
}
}