Java Method.isVarArgs方法代碼示例

import java.lang.reflect.Method; //導入方法依賴的package包/類
/**
 * Filter all methods to ensure following conditions:
 *
 * <ul><li>Method name is @name</li>
 *
 * <li>Method is <tt>public<tt></li>
 *
 * <li>Method is not <tt>abstract</tt></li>.
 *
 * <li>Method does not have variable number of arguments</li>
 *
 * <li>Return type of method is @returnType</li>
 *
 * <li>All parameter fields are of type {@link String}, {@link Integer} or {@link Double}</li>
 *
 * <li>All parameters are annotated with {@link Param}</li> </ul>
 *
 * @param methods Array of methods to be filtered.
 * @param seekedName Name of the methods we are looking for.
 * @param returnType Expected return type of filtered methods.
 * @return Array of methods with @name.
 */
private Method[] filterMethods(Method[] methods, String seekedName, Class<?> returnType) {
    List<Method> filteredMethods = new LinkedList<Method>();

    for (Method testedMethod : methods) {
        String testedMethodName = testedMethod.getName();
        boolean methodIsPublic = (testedMethod.getModifiers() & Modifier.PUBLIC) == Modifier.PUBLIC;
        boolean methodIsAbstract = (testedMethod.getModifiers() & Modifier.ABSTRACT) == Modifier.ABSTRACT;
        boolean correctReturnType = returnType.isAssignableFrom(testedMethod.getReturnType());
        boolean acceptedParams = areParamsAcceptable(testedMethod, true, allowedParamClasses);
        boolean annotatedParams = areParamsAnnotated(testedMethod);

        if (testedMethodName.equals(seekedName)
                && methodIsPublic
                && !methodIsAbstract
                && !testedMethod.isVarArgs()
                && correctReturnType
                && acceptedParams
                && annotatedParams) {
            filteredMethods.add(testedMethod);
        }
    }
    return filteredMethods.toArray(new Method[filteredMethods.size()]);
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
/**
 * Returns the result of method execution.
 *
 * @param type  the base class
 * @param args  the array of arguments
 * @return the value of this element
 * @throws Exception if calculation is failed
 */
@Override
protected ValueObject getValueObject(Class<?> type, Object[] args) throws Exception {
    Object bean = getContextBean();
    Class<?>[] types = getArgumentTypes(args);
    Method method = (type != null)
            ? MethodFinder.findStaticMethod(type, this.name, types)
            : MethodFinder.findMethod(bean.getClass(), this.name, types);

    if (method.isVarArgs()) {
        args = getArguments(args, method.getParameterTypes());
    }
    Object value = MethodUtil.invoke(method, bean, args);
    return method.getReturnType().equals(void.class)
            ? ValueObjectImpl.VOID
            : ValueObjectImpl.create(value);
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
@Override
public void visit(Node node) throws ELException {
	if (node instanceof AstFunction) {

		AstFunction funcNode = (AstFunction) node;

		if (this.fnMapper == null) {
			throw new ELException(MessageFactory.get("error.fnMapper.null"));
		}
		Method m = fnMapper.resolveFunction(funcNode.getPrefix(), funcNode.getLocalName());
		if (m == null) {
			throw new ELException(MessageFactory.get("error.fnMapper.method", funcNode.getOutputName()));
		}
		int methodParameterCount = m.getParameterTypes().length;
		int inputParameterCount = node.jjtGetNumChildren();
		if (m.isVarArgs() && inputParameterCount < methodParameterCount - 1
				|| !m.isVarArgs() && inputParameterCount != methodParameterCount) {
			throw new ELException(MessageFactory.get("error.fnMapper.paramcount", funcNode.getOutputName(),
					"" + methodParameterCount, "" + node.jjtGetNumChildren()));
		}
	} else if (node instanceof AstIdentifier && this.varMapper != null) {
		String variable = ((AstIdentifier) node).getImage();

		// simply capture it
		this.varMapper.resolveVariable(variable);
	}
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
private Object[] extractArgs(Method method, Object[] args) {
	if (!method.isVarArgs()) {
		return args;
	}
	Object[] varArgs = ObjectUtils.toObjectArray(args[args.length - 1]);
	Object[] combinedArgs = new Object[args.length - 1 + varArgs.length];
	System.arraycopy(args, 0, combinedArgs, 0, args.length - 1);
	System.arraycopy(varArgs, 0, combinedArgs, args.length - 1, varArgs.length);
	return combinedArgs;
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
/**
 * Execute a function represented as a java.lang.reflect.Method.
 *
 * @param state the expression evaluation state
 * @param the java method to invoke
 * @return the return value of the invoked Java method
 * @throws EvaluationException if there is any problem invoking the method
 */
private TypedValue executeFunctionJLRMethod(ExpressionState state, Method method) throws EvaluationException {
	Object[] functionArgs = getArguments(state);

	if (!method.isVarArgs() && method.getParameterTypes().length != functionArgs.length) {
		throw new SpelEvaluationException(SpelMessage.INCORRECT_NUMBER_OF_ARGUMENTS_TO_FUNCTION,
				functionArgs.length, method.getParameterTypes().length);
	}
	// Only static methods can be called in this way
	if (!Modifier.isStatic(method.getModifiers())) {
		throw new SpelEvaluationException(getStartPosition(),
				SpelMessage.FUNCTION_MUST_BE_STATIC,
				method.getDeclaringClass().getName() + "." + method.getName(), this.name);
	}

	// Convert arguments if necessary and remap them for varargs if required
	if (functionArgs != null) {
		TypeConverter converter = state.getEvaluationContext().getTypeConverter();
		ReflectionHelper.convertAllArguments(converter, functionArgs, method);
	}
	if (method.isVarArgs()) {
		functionArgs = ReflectionHelper.setupArgumentsForVarargsInvocation(
				method.getParameterTypes(), functionArgs);
	}

	try {
		ReflectionUtils.makeAccessible(method);
		Object result = method.invoke(method.getClass(), functionArgs);
		return new TypedValue(result, new TypeDescriptor(new MethodParameter(method,-1)).narrow(result));
	}
	catch (Exception ex) {
		throw new SpelEvaluationException(getStartPosition(), ex, SpelMessage.EXCEPTION_DURING_FUNCTION_CALL,
				this.name, ex.getMessage());
	}
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
public ReflectiveMethodExecutor(Method method) {
	this.method = method;
	if (method.isVarArgs()) {
		Class<?>[] paramTypes = method.getParameterTypes();
		this.varargsPosition = paramTypes.length - 1;
	}
	else {
		this.varargsPosition = null;
	}
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
@Override
public Object getValue(EvaluationContext ctx) throws ELException {

	FunctionMapper fnMapper = ctx.getFunctionMapper();

	// quickly validate again for this request
	if (fnMapper == null) {
		throw new ELException(MessageFactory.get("error.fnMapper.null"));
	}
	Method m = fnMapper.resolveFunction(this.prefix, this.localName);
	if (m == null) {
		throw new ELException(MessageFactory.get("error.fnMapper.method", this.getOutputName()));
	}

	Class<?>[] paramTypes = m.getParameterTypes();
	Object[] params = null;
	Object result = null;
	int inputParameterCount = this.jjtGetNumChildren();
	int methodParameterCount = paramTypes.length;
	if (inputParameterCount == 0 && methodParameterCount == 1 && m.isVarArgs()) {
		params = new Object[] { null };
	} else if (inputParameterCount > 0) {
		params = new Object[methodParameterCount];
		try {
			for (int i = 0; i < methodParameterCount; i++) {
				if (m.isVarArgs() && i == methodParameterCount - 1) {
					if (inputParameterCount < methodParameterCount) {
						params[i] = new Object[] { null };
					} else if (inputParameterCount == methodParameterCount && paramTypes[i].isArray()) {
						params[i] = this.jjtGetChild(i).getValue(ctx);
					} else {
						Object[] varargs = new Object[inputParameterCount - methodParameterCount + 1];
						Class<?> target = paramTypes[i].getComponentType();
						for (int j = i; j < inputParameterCount; j++) {
							varargs[j - i] = this.jjtGetChild(j).getValue(ctx);
							varargs[j - i] = coerceToType(varargs[j - i], target);
						}
						params[i] = varargs;
					}
				} else {
					params[i] = this.jjtGetChild(i).getValue(ctx);
				}
				params[i] = coerceToType(params[i], paramTypes[i]);
			}
		} catch (ELException ele) {
			throw new ELException(MessageFactory.get("error.function", this.getOutputName()), ele);
		}
	}
	try {
		result = m.invoke(null, params);
	} catch (IllegalAccessException iae) {
		throw new ELException(MessageFactory.get("error.function", this.getOutputName()), iae);
	} catch (InvocationTargetException ite) {
		Throwable cause = ite.getCause();
		if (cause instanceof ThreadDeath) {
			throw (ThreadDeath) cause;
		}
		if (cause instanceof VirtualMachineError) {
			throw (VirtualMachineError) cause;
		}
		throw new ELException(MessageFactory.get("error.function", this.getOutputName()), cause);
	}
	return result;
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
public Method linkMethod(String methodName, Map<? extends String, ? extends ParameterKind> params) {
    Collection<Class<?>> paramTypes = new LinkedList<Class<?>>();

    for (Entry<? extends String, ? extends ParameterKind> e : params.entrySet()) {
        switch ((ParameterKind) e.getValue()) {
            case VARIABLE:
                paramTypes.add(Variable.class);
                break;
            case STRING_LITERAL:
                paramTypes.add(String.class);
                break;
            case ENUM_CONSTANT:
                Enum<?> constant = loadEnumConstant(e.getKey());

                paramTypes.add(constant.getDeclaringClass());
                break;
        }
    }

    Method varArgMethod = null;
    
    for (Class<?> clazz : ruleUtilities) {
        OUTER: for (Method m : clazz.getDeclaredMethods()) {
            if (methodName.equals(m.getName())) {
                Class<?>[] p = m.getParameterTypes();
                int c = 0;
                Iterator<Class<?>> it = paramTypes.iterator();

                for ( ; it.hasNext() && c < p.length; ) {
                    Class<?> paramClass = it.next();
                    Class<?> declaredClass = p[c++];

                    if (declaredClass.equals(paramClass))
                        continue;

                    if (   m.isVarArgs()
                        && declaredClass.isArray()
                        && declaredClass.getComponentType().equals(paramClass)
                        && c == p.length) {
                        while (it.hasNext()) {
                            if (!paramClass.equals(it.next())) {
                                continue OUTER;
                            }
                        }

                        break;
                    }

                    continue OUTER;
                }

                if (!it.hasNext() && c == p.length) {
                    if (!m.isVarArgs()) {
                        return m;
                    }
                    if (varArgMethod == null) {
                        varArgMethod = m;
                    }
                }
            }
        }
    }

    return varArgMethod;
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
public void testLoggerUsageCheckerCompatibilityWithLog4j2Logger() throws NoSuchMethodException {
    for (Method method : Logger.class.getMethods()) {
        if (ESLoggerUsageChecker.LOGGER_METHODS.contains(method.getName())) {
            assertThat(method.getParameterTypes().length, greaterThanOrEqualTo(1));
            int markerOffset = method.getParameterTypes()[0].equals(Marker.class) ? 1 : 0;
            int paramLength = method.getParameterTypes().length - markerOffset;
            if (method.isVarArgs()) {
                assertEquals(2, paramLength);
                assertEquals(String.class, method.getParameterTypes()[markerOffset]);
                assertThat(method.getParameterTypes()[markerOffset + 1], Matchers.<Class<?>>isOneOf(Object[].class, Supplier[].class));
            } else {
                assertThat(method.getParameterTypes()[markerOffset], Matchers.<Class<?>>isOneOf(Message.class, MessageSupplier.class,
                    CharSequence.class, Object.class, String.class, Supplier.class));

                if (paramLength == 2) {
                    assertThat(method.getParameterTypes()[markerOffset + 1], Matchers.<Class<?>>isOneOf(Throwable.class, Object.class));
                    if (method.getParameterTypes()[markerOffset + 1].equals(Object.class)) {
                        assertEquals(String.class, method.getParameterTypes()[markerOffset]);
                    }
                }
                if (paramLength > 2) {
                    assertEquals(String.class, method.getParameterTypes()[markerOffset]);
                    assertThat(paramLength, lessThanOrEqualTo(11));
                    for (int i = 1; i < paramLength; i++) {
                        assertEquals(Object.class, method.getParameterTypes()[markerOffset + i]);
                    }
                }
            }
        }
    }

    for (String methodName : ESLoggerUsageChecker.LOGGER_METHODS) {
        assertEquals(48, Stream.of(Logger.class.getMethods()).filter(m -> methodName.equals(m.getName())).count());
    }

    for (Constructor<?> constructor : ParameterizedMessage.class.getConstructors()) {
        assertThat(constructor.getParameterTypes().length, greaterThanOrEqualTo(2));
        assertEquals(String.class, constructor.getParameterTypes()[0]);
        assertThat(constructor.getParameterTypes()[1], Matchers.<Class<?>>isOneOf(String[].class, Object[].class, Object.class));

        if (constructor.getParameterTypes().length > 2) {
            assertEquals(3, constructor.getParameterTypes().length);
            if (constructor.getParameterTypes()[1].equals(Object.class)) {
                assertEquals(Object.class, constructor.getParameterTypes()[2]);
            } else {
                assertEquals(Throwable.class, constructor.getParameterTypes()[2]);
            }
        }
    }

    assertEquals(5, ParameterizedMessage.class.getConstructors().length);
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
private Object[] convertArgs(Object[] src, Method m) {
    Class<?>[] types = m.getParameterTypes();
    if (types.length == 0) {
        // Treated as if parameters have been provided so src is ignored
        return EMPTY_ARRAY;
    }
    
    int paramCount = types.length;

    if (m.isVarArgs() && paramCount > 1 && (src == null || paramCount > src.length) ||
            !m.isVarArgs() && (paramCount > 0 && src == null ||
                    src != null && src.length != paramCount)) {
        String srcCount = null;
        if (src != null) {
            srcCount = Integer.toString(src.length);
        }
        String msg;
        if (m.isVarArgs()) {
            msg = MessageFactory.get("error.invoke.tooFewParams",
                    m.getName(), srcCount, Integer.toString(paramCount));
        } else {
            msg = MessageFactory.get("error.invoke.wrongParams",
                    m.getName(), srcCount, Integer.toString(paramCount));
        }
        throw new IllegalArgumentException(msg);
    }

    if (src == null) {
        // Must be a varargs method with a single parameter.
        // Use a new array every time since the called code could modify the
        // contents of the array
        return new Object[1];
    }

    Object[] dest = new Object[paramCount];

    for (int i = 0; i < paramCount - 1; i++) {
        dest[i] = ELSupport.coerceToType(src[i], types[i]);
    }

    if (m.isVarArgs()) {
        Object[] varArgs = (Object[]) Array.newInstance(
                m.getParameterTypes()[paramCount - 1].getComponentType(),
                src.length - (paramCount - 1));
        for (int i = 0; i < src.length - (paramCount - 1); i ++) {
            varArgs[i] = ELSupport.coerceToType(src[paramCount - 1 + i],
                    types[paramCount - 1].getComponentType());
        }
        dest[paramCount - 1] = varArgs;
    } else {
        dest[paramCount - 1] = ELSupport.coerceToType(
                src[paramCount - 1], types[paramCount - 1]);
    }

    return dest;
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
private static int getAccessModifiers(final Method method) {
    return ACC_PUBLIC | (method.isVarArgs() ? ACC_VARARGS : 0);
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
/**
 * Tells whether a method invocation of 'origin' can be transformed in a
 * method invocation of 'target'.
 * This method only look at the parameter signatures, it doesn't look at
 * the name, nor does it look at the return types.
 * <p>
 * Example:
 * <ul>
 *     <li>java.util.logging.Logger.log(Level, String, Object) can be invoked as<br>
     java.util.logging.spi.Logger.log(Level, String, Object...) because the
     last parameter in 'target' is a varargs.</li>
 *     <li>java.util.logging.Logger.log(Level, String) can also be invoked as<br>
     java.util.logging.spi.Logger.log(Level, String, Object...) for the
     same reason.</li>
 * </ul>
 * <p>
 * The algorithm is tailored for our needs: when the last parameter in the
 * target is a vararg, and when origin & target have the same number of
 * parameters, then we consider that the types of the last parameter *must*
 * match.
 * <p>
 * Similarly - we do not consider that o(X x, Y y, Y y) matches t(X x, Y... y)
 * although strictly speaking, it should...
 *
 * @param origin The method in the original class
 * @param target The correspondent candidate in the target class
 * @return true if a method invocation of 'origin' can be transformed in a
 * method invocation of 'target'.
 */
public boolean canBeInvokedAs(Method origin, Method target,
                              Map<Class<?>,Class<?>> substitutes) {
    final Class<?>[] xParams = target.getParameterTypes();
    final Class<?>[] mParams = Stream.of(origin.getParameterTypes())
            .map((x) -> substitutes.getOrDefault(x, x))
            .collect(Collectors.toList()).toArray(new Class<?>[0]);
    if (Arrays.deepEquals(xParams, mParams)) return true;
    if (target.isVarArgs()) {
        if (xParams.length == mParams.length) {
            if (xParams[xParams.length-1].isArray()) {
                return mParams[mParams.length -1].equals(
                        xParams[xParams.length -1].getComponentType());
            }
        } else if (xParams.length == mParams.length + 1) {
            return Arrays.deepEquals(
                    Arrays.copyOfRange(xParams, 0, xParams.length-1), mParams);
        }
    }
    return false;
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
private static boolean parameterLengthMatches(Method m, MethodCacheKey key) {
	return m.isVarArgs() || m.getParameterTypes().length == key.arguments;
}
 

import java.lang.reflect.Method; //導入方法依賴的package包/類
private Object[] convertArgs(Object[] src, Method m) {
	Class<?>[] types = m.getParameterTypes();
	if (types.length == 0) {
		// Treated as if parameters have been provided so src is ignored
		return EMPTY_ARRAY;
	}

	int paramCount = types.length;

	if (m.isVarArgs() && paramCount > 1 && (src == null || paramCount > src.length)
			|| !m.isVarArgs() && (paramCount > 0 && src == null || src != null && src.length != paramCount)) {
		String srcCount = null;
		if (src != null) {
			srcCount = Integer.toString(src.length);
		}
		String msg;
		if (m.isVarArgs()) {
			msg = MessageFactory.get("error.invoke.tooFewParams", m.getName(), srcCount,
					Integer.toString(paramCount));
		} else {
			msg = MessageFactory.get("error.invoke.wrongParams", m.getName(), srcCount,
					Integer.toString(paramCount));
		}
		throw new IllegalArgumentException(msg);
	}

	if (src == null) {
		// Must be a varargs method with a single parameter.
		// Use a new array every time since the called code could modify the
		// contents of the array
		return new Object[1];
	}

	Object[] dest = new Object[paramCount];

	for (int i = 0; i < paramCount - 1; i++) {
		dest[i] = ELSupport.coerceToType(src[i], types[i]);
	}

	if (m.isVarArgs()) {
		Object[] varArgs = (Object[]) Array.newInstance(m.getParameterTypes()[paramCount - 1].getComponentType(),
				src.length - (paramCount - 1));
		for (int i = 0; i < src.length - (paramCount - 1); i++) {
			varArgs[i] = ELSupport.coerceToType(src[paramCount - 1 + i], types[paramCount - 1].getComponentType());
		}
		dest[paramCount - 1] = varArgs;
	} else {
		dest[paramCount - 1] = ELSupport.coerceToType(src[paramCount - 1], types[paramCount - 1]);
	}

	return dest;
}