Java MethodVisitor.visitMethodInsn方法代码示例

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
/**
 * Walk through a possible tree of nodes that combine strings and append
 * them all to the same (on stack) StringBuilder.
 */
private void walk(MethodVisitor mv, CodeFlow cf, SpelNodeImpl operand) {
	if (operand instanceof OpPlus) {
		OpPlus plus = (OpPlus)operand;
		walk(mv,cf,plus.getLeftOperand());
		walk(mv,cf,plus.getRightOperand());
	}
	else {
		cf.enterCompilationScope();
		operand.generateCode(mv,cf);
		if (!"Ljava/lang/String".equals(cf.lastDescriptor())) {
			mv.visitTypeInsn(CHECKCAST, "java/lang/String");
		}
		cf.exitCompilationScope();
		mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
	}
}
 

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
	String descriptor = cf.lastDescriptor();
	if (descriptor == null || !descriptor.equals("Ljava/util/Map")) {
		if (descriptor == null) {
			cf.loadTarget(mv);
		}
		CodeFlow.insertCheckCast(mv, "Ljava/util/Map");
	}
	mv.visitLdcInsn(propertyName);
	mv.visitMethodInsn(INVOKEINTERFACE, "java/util/Map", "get","(Ljava/lang/Object;)Ljava/lang/Object;",true);
}
 

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
/**
 * Determine the appropriate boxing instruction for a specific type (if it needs
 * boxing) and insert the instruction into the supplied visitor.
 * @param mv the target visitor for the new instructions
 * @param ch the descriptor of the type that might need boxing
 */
public static void insertBoxIfNecessary(MethodVisitor mv, char ch) {
	switch (ch) {
		case 'Z':
			mv.visitMethodInsn(INVOKESTATIC, "java/lang/Boolean", "valueOf", "(Z)Ljava/lang/Boolean;", false);
			break;
		case 'B':
			mv.visitMethodInsn(INVOKESTATIC, "java/lang/Byte", "valueOf", "(B)Ljava/lang/Byte;", false);
			break;
		case 'C':
			mv.visitMethodInsn(INVOKESTATIC, "java/lang/Character", "valueOf", "(C)Ljava/lang/Character;", false);
			break;
		case 'D':
			mv.visitMethodInsn(INVOKESTATIC, "java/lang/Double", "valueOf", "(D)Ljava/lang/Double;", false);
			break;
		case 'F':
			mv.visitMethodInsn(INVOKESTATIC, "java/lang/Float", "valueOf", "(F)Ljava/lang/Float;", false);
			break;
		case 'I':
			mv.visitMethodInsn(INVOKESTATIC, "java/lang/Integer", "valueOf", "(I)Ljava/lang/Integer;", false);
			break;
		case 'J':
			mv.visitMethodInsn(INVOKESTATIC, "java/lang/Long", "valueOf", "(J)Ljava/lang/Long;", false);
			break;
		case 'S':
			mv.visitMethodInsn(INVOKESTATIC, "java/lang/Short", "valueOf", "(S)Ljava/lang/Short;", false);
			break;
		case 'L':
		case 'V':
		case '[':
			// no box needed
			break;
		default:
			throw new IllegalArgumentException("Boxing should not be attempted for descriptor '" + ch + "'");
	}
}
 

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
/**
 * For numbers, use the appropriate method on the number to convert it to the primitive type requested.
 * @param mv the method visitor into which instructions should be inserted
 * @param targetDescriptor the primitive type desired as output
 * @param stackDescriptor the descriptor of the type on top of the stack
 */
public static void insertUnboxNumberInsns(MethodVisitor mv, char targetDescriptor, String stackDescriptor) {
	switch (targetDescriptor) {
		case 'D':
			if (stackDescriptor.equals("Ljava/lang/Object")) {
				mv.visitTypeInsn(CHECKCAST, "java/lang/Number");
			}
			mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Number", "doubleValue", "()D", false);
			break;
		case 'F':
			if (stackDescriptor.equals("Ljava/lang/Object")) {
				mv.visitTypeInsn(CHECKCAST, "java/lang/Number");
			}
			mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Number", "floatValue", "()F", false);
			break;
		case 'J':
			if (stackDescriptor.equals("Ljava/lang/Object")) {
				mv.visitTypeInsn(CHECKCAST, "java/lang/Number");
			}
			mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Number", "longValue", "()J", false);
			break;
		case 'I':
			if (stackDescriptor.equals("Ljava/lang/Object")) {
				mv.visitTypeInsn(CHECKCAST, "java/lang/Number");
			}
			mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Number", "intValue", "()I", false);
			break;
		// does not handle Z, B, C, S
		default:
			throw new IllegalArgumentException("Unboxing should not be attempted for descriptor '" + targetDescriptor + "'");
	}
}
 

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
	if (this.name.equals(ROOT)) {
		mv.visitVarInsn(ALOAD,1);
	}
	else {
		mv.visitVarInsn(ALOAD, 2);
		mv.visitLdcInsn(name);
		mv.visitMethodInsn(INVOKEINTERFACE, "org/springframework/expression/EvaluationContext", "lookupVariable", "(Ljava/lang/String;)Ljava/lang/Object;",true);
	}
	CodeFlow.insertCheckCast(mv,this.exitTypeDescriptor);
	cf.pushDescriptor(this.exitTypeDescriptor);
}
 

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
	ReflectiveConstructorExecutor executor = ((ReflectiveConstructorExecutor) this.cachedExecutor);
	Constructor<?> constructor = executor.getConstructor();		
	String classDesc = constructor.getDeclaringClass().getName().replace('.', '/');
	mv.visitTypeInsn(NEW, classDesc);
	mv.visitInsn(DUP);
	// children[0] is the type of the constructor, don't want to include that in argument processing
	SpelNodeImpl[] arguments = new SpelNodeImpl[children.length - 1];
	System.arraycopy(children, 1, arguments, 0, children.length - 1);
	generateCodeForArguments(mv, cf, constructor, arguments);	
	mv.visitMethodInsn(INVOKESPECIAL, classDesc, "<init>", CodeFlow.createSignatureDescriptor(constructor), false);
	cf.pushDescriptor(this.exitTypeDescriptor);
}
 

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
	boolean isStatic = Modifier.isStatic(this.member.getModifiers());
	String descriptor = cf.lastDescriptor();
	String classDesc = this.member.getDeclaringClass().getName().replace('.', '/');

	if (!isStatic) {
		if (descriptor == null) {
			cf.loadTarget(mv);
		}
		if (descriptor == null || !classDesc.equals(descriptor.substring(1))) {
			mv.visitTypeInsn(CHECKCAST, classDesc);
		}
	}
	else {
		if (descriptor != null) {
			// A static field/method call will not consume what is on the stack,
			// it needs to be popped off.
			mv.visitInsn(POP);
		}
	}

	if (this.member instanceof Method) {
		mv.visitMethodInsn((isStatic ? INVOKESTATIC : INVOKEVIRTUAL), classDesc, this.member.getName(),
				CodeFlow.createSignatureDescriptor((Method) this.member), false);
	}
	else {
		mv.visitFieldInsn((isStatic ? GETSTATIC : GETFIELD), classDesc, this.member.getName(),
				CodeFlow.toJvmDescriptor(((Field) this.member).getType()));
	}
}
 

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
@Override
public void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf) {
	String descriptor = cf.lastDescriptor();
	if (descriptor == null) {
		cf.loadTarget(mv);
	}
	mv.visitLdcInsn(propertyName);
	mv.visitMethodInsn(INVOKEINTERFACE, "java/util/Map", "get","(Ljava/lang/Object;)Ljava/lang/Object;",true);
}
 

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
void generateClinitCode(String clazzname, String constantFieldName, MethodVisitor mv, CodeFlow codeflow, boolean nested) {
	mv.visitTypeInsn(NEW, "java/util/ArrayList");
	mv.visitInsn(DUP);
	mv.visitMethodInsn(INVOKESPECIAL, "java/util/ArrayList", "<init>", "()V", false);
	if (!nested) {
		mv.visitFieldInsn(PUTSTATIC, clazzname, constantFieldName, "Ljava/util/List;");
	}
	int childcount = getChildCount();		
	for (int c=0; c < childcount; c++) {
		if (!nested) {
			mv.visitFieldInsn(GETSTATIC, clazzname, constantFieldName, "Ljava/util/List;");
		}
		else {
			mv.visitInsn(DUP);
		}
		// The children might be further lists if they are not constants. In this
		// situation do not call back into generateCode() because it will register another clinit adder.
		// Instead, directly build the list here:
		if (children[c] instanceof InlineList) {
			((InlineList)children[c]).generateClinitCode(clazzname, constantFieldName, mv, codeflow, true);
		}
		else {
			children[c].generateCode(mv, codeflow);
			if (CodeFlow.isPrimitive(codeflow.lastDescriptor())) {
				CodeFlow.insertBoxIfNecessary(mv, codeflow.lastDescriptor().charAt(0));
			}
		}
		mv.visitMethodInsn(INVOKEINTERFACE, "java/util/List", "add", "(Ljava/lang/Object;)Z", true);
		mv.visitInsn(POP);
	}
}
 

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
/**
 * If the codeflow shows the last expression evaluated to java.lang.Boolean then
 * insert the necessary instructions to unbox that to a boolean primitive.
 * @param mv the visitor into which new instructions should be inserted
 */
public void unboxBooleanIfNecessary(MethodVisitor mv) {
	if (lastDescriptor().equals("Ljava/lang/Boolean")) {
		mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Boolean", "booleanValue", "()Z", false);
	}
}
 

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
	if (this.exitTypeDescriptor == "Ljava/lang/String") {
		mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
		mv.visitInsn(DUP);
		mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "()V", false);
		walk(mv,cf,getLeftOperand());
		walk(mv,cf,getRightOperand());
		mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;", false);
	}
	else {
		getLeftOperand().generateCode(mv, cf);
		String leftDesc = getLeftOperand().exitTypeDescriptor;
		CodeFlow.insertNumericUnboxOrPrimitiveTypeCoercion(mv, leftDesc, this.exitTypeDescriptor.charAt(0));
		if (this.children.length > 1) {
			cf.enterCompilationScope();
			getRightOperand().generateCode(mv, cf);
			String rightDesc = getRightOperand().exitTypeDescriptor;
			cf.exitCompilationScope();
			CodeFlow.insertNumericUnboxOrPrimitiveTypeCoercion(mv, rightDesc, this.exitTypeDescriptor.charAt(0));
			switch (this.exitTypeDescriptor.charAt(0)) {
				case 'I':
					mv.visitInsn(IADD);
					break;
				case 'J':
					mv.visitInsn(LADD);
					break;
				case 'F': 
					mv.visitInsn(FADD);
					break;
				case 'D':
					mv.visitInsn(DADD);
					break;				
				default:
					throw new IllegalStateException(
							"Unrecognized exit type descriptor: '" + this.exitTypeDescriptor + "'");
			}
		}
	}
	cf.pushDescriptor(this.exitTypeDescriptor);
}
 

import org.springframework.asm.MethodVisitor; //导入方法依赖的package包/类
@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
	CachedMethodExecutor executorToCheck = this.cachedExecutor;
	if (executorToCheck == null || !(executorToCheck.get() instanceof ReflectiveMethodExecutor)) {
		throw new IllegalStateException("No applicable cached executor found: " + executorToCheck);
	}

	ReflectiveMethodExecutor methodExecutor = (ReflectiveMethodExecutor) executorToCheck.get();
	Method method = methodExecutor.getMethod();
	boolean isStaticMethod = Modifier.isStatic(method.getModifiers());
	String descriptor = cf.lastDescriptor();

	if (descriptor == null) {
		if (!isStaticMethod) {
			// Nothing on the stack but something is needed
			cf.loadTarget(mv);
		}
	}
	else {
		if (isStaticMethod) {
			// Something on the stack when nothing is needed
			mv.visitInsn(POP);
		}
	}
	
	if (CodeFlow.isPrimitive(descriptor)) {
		CodeFlow.insertBoxIfNecessary(mv, descriptor.charAt(0));
	}

	String classDesc = (Modifier.isPublic(method.getDeclaringClass().getModifiers()) ?
			method.getDeclaringClass().getName().replace('.', '/') :
			methodExecutor.getPublicDeclaringClass().getName().replace('.', '/'));
	if (!isStaticMethod) {
		if (descriptor == null || !descriptor.substring(1).equals(classDesc)) {
			CodeFlow.insertCheckCast(mv, "L" + classDesc);
		}
	}

	generateCodeForArguments(mv, cf, method, this.children);
	mv.visitMethodInsn((isStaticMethod ? INVOKESTATIC : INVOKEVIRTUAL), classDesc, method.getName(),
			CodeFlow.createSignatureDescriptor(method), method.getDeclaringClass().isInterface());
	cf.pushDescriptor(this.exitTypeDescriptor);
}