Example usage for org.springframework.beans.factory.config ConstructorArgumentValues getArgumentValue

List of usage examples for org.springframework.beans.factory.config ConstructorArgumentValues getArgumentValue

Introduction

In this page you can find the example usage for org.springframework.beans.factory.config ConstructorArgumentValues getArgumentValue.

Prototype

@Nullable
public ValueHolder getArgumentValue(int index, @Nullable Class<?> requiredType, @Nullable String requiredName,
        @Nullable Set<ValueHolder> usedValueHolders) 

Source Link

Document

Look for an argument value that either corresponds to the given index in the constructor argument list or generically matches by type.

Usage

From source file:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.java

/**
 * Determine the target type for the given bean definition which is based on
 * a factory method. Only called if there is no singleton instance registered
 * for the target bean already.// ww w .j a va2  s  .c o  m
 * <p>This implementation determines the type matching {@link #createBean}'s
 * different creation strategies. As far as possible, we'll perform static
 * type checking to avoid creation of the target bean.
 * @param beanName the name of the bean (for error handling purposes)
 * @param mbd the merged bean definition for the bean
 * @param typesToMatch the types to match in case of internal type matching purposes
 * (also signals that the returned {@code Class} will never be exposed to application code)
 * @return the type for the bean if determinable, or {@code null} otherwise
 * @see #createBean
 */
@Nullable
protected Class<?> getTypeForFactoryMethod(String beanName, RootBeanDefinition mbd, Class<?>... typesToMatch) {
    ResolvableType cachedReturnType = mbd.factoryMethodReturnType;
    if (cachedReturnType != null) {
        return cachedReturnType.resolve();
    }

    Class<?> factoryClass;
    boolean isStatic = true;

    String factoryBeanName = mbd.getFactoryBeanName();
    if (factoryBeanName != null) {
        if (factoryBeanName.equals(beanName)) {
            throw new BeanDefinitionStoreException(mbd.getResourceDescription(), beanName,
                    "factory-bean reference points back to the same bean definition");
        }
        // Check declared factory method return type on factory class.
        factoryClass = getType(factoryBeanName);
        isStatic = false;
    } else {
        // Check declared factory method return type on bean class.
        factoryClass = resolveBeanClass(mbd, beanName, typesToMatch);
    }

    if (factoryClass == null) {
        return null;
    }
    factoryClass = ClassUtils.getUserClass(factoryClass);

    // If all factory methods have the same return type, return that type.
    // Can't clearly figure out exact method due to type converting / autowiring!
    Class<?> commonType = null;
    Method uniqueCandidate = null;
    int minNrOfArgs = (mbd.hasConstructorArgumentValues()
            ? mbd.getConstructorArgumentValues().getArgumentCount()
            : 0);
    Method[] candidates = this.factoryMethodCandidateCache.computeIfAbsent(factoryClass,
            ReflectionUtils::getUniqueDeclaredMethods);

    for (Method candidate : candidates) {
        if (Modifier.isStatic(candidate.getModifiers()) == isStatic && mbd.isFactoryMethod(candidate)
                && candidate.getParameterCount() >= minNrOfArgs) {
            // Declared type variables to inspect?
            if (candidate.getTypeParameters().length > 0) {
                try {
                    // Fully resolve parameter names and argument values.
                    Class<?>[] paramTypes = candidate.getParameterTypes();
                    String[] paramNames = null;
                    ParameterNameDiscoverer pnd = getParameterNameDiscoverer();
                    if (pnd != null) {
                        paramNames = pnd.getParameterNames(candidate);
                    }
                    ConstructorArgumentValues cav = mbd.getConstructorArgumentValues();
                    Set<ConstructorArgumentValues.ValueHolder> usedValueHolders = new HashSet<>(
                            paramTypes.length);
                    Object[] args = new Object[paramTypes.length];
                    for (int i = 0; i < args.length; i++) {
                        ConstructorArgumentValues.ValueHolder valueHolder = cav.getArgumentValue(i,
                                paramTypes[i], (paramNames != null ? paramNames[i] : null), usedValueHolders);
                        if (valueHolder == null) {
                            valueHolder = cav.getGenericArgumentValue(null, null, usedValueHolders);
                        }
                        if (valueHolder != null) {
                            args[i] = valueHolder.getValue();
                            usedValueHolders.add(valueHolder);
                        }
                    }
                    Class<?> returnType = AutowireUtils.resolveReturnTypeForFactoryMethod(candidate, args,
                            getBeanClassLoader());
                    uniqueCandidate = (commonType == null && returnType == candidate.getReturnType() ? candidate
                            : null);
                    commonType = ClassUtils.determineCommonAncestor(returnType, commonType);
                    if (commonType == null) {
                        // Ambiguous return types found: return null to indicate "not determinable".
                        return null;
                    }
                } catch (Throwable ex) {
                    if (logger.isDebugEnabled()) {
                        logger.debug("Failed to resolve generic return type for factory method: " + ex);
                    }
                }
            } else {
                uniqueCandidate = (commonType == null ? candidate : null);
                commonType = ClassUtils.determineCommonAncestor(candidate.getReturnType(), commonType);
                if (commonType == null) {
                    // Ambiguous return types found: return null to indicate "not determinable".
                    return null;
                }
            }
        }
    }

    if (commonType == null) {
        return null;
    }
    // Common return type found: all factory methods return same type. For a non-parameterized
    // unique candidate, cache the full type declaration context of the target factory method.
    cachedReturnType = (uniqueCandidate != null ? ResolvableType.forMethodReturnType(uniqueCandidate)
            : ResolvableType.forClass(commonType));
    mbd.factoryMethodReturnType = cachedReturnType;
    return cachedReturnType.resolve();
}

From source file:org.springframework.beans.factory.support.ConstructorResolver.java

/**
 * Create an array of arguments to invoke a constructor or factory method,
 * given the resolved constructor argument values.
 *//*from  w  w w .  ja  va2 s. c  o m*/
private ArgumentsHolder createArgumentArray(String beanName, RootBeanDefinition mbd,
        @Nullable ConstructorArgumentValues resolvedValues, BeanWrapper bw, Class<?>[] paramTypes,
        @Nullable String[] paramNames, Executable executable, boolean autowiring, boolean fallback)
        throws UnsatisfiedDependencyException {

    TypeConverter customConverter = this.beanFactory.getCustomTypeConverter();
    TypeConverter converter = (customConverter != null ? customConverter : bw);

    ArgumentsHolder args = new ArgumentsHolder(paramTypes.length);
    Set<ConstructorArgumentValues.ValueHolder> usedValueHolders = new HashSet<>(paramTypes.length);
    Set<String> autowiredBeanNames = new LinkedHashSet<>(4);

    for (int paramIndex = 0; paramIndex < paramTypes.length; paramIndex++) {
        Class<?> paramType = paramTypes[paramIndex];
        String paramName = (paramNames != null ? paramNames[paramIndex] : "");
        // Try to find matching constructor argument value, either indexed or generic.
        ConstructorArgumentValues.ValueHolder valueHolder = null;
        if (resolvedValues != null) {
            valueHolder = resolvedValues.getArgumentValue(paramIndex, paramType, paramName, usedValueHolders);
            // If we couldn't find a direct match and are not supposed to autowire,
            // let's try the next generic, untyped argument value as fallback:
            // it could match after type conversion (for example, String -> int).
            if (valueHolder == null
                    && (!autowiring || paramTypes.length == resolvedValues.getArgumentCount())) {
                valueHolder = resolvedValues.getGenericArgumentValue(null, null, usedValueHolders);
            }
        }
        if (valueHolder != null) {
            // We found a potential match - let's give it a try.
            // Do not consider the same value definition multiple times!
            usedValueHolders.add(valueHolder);
            Object originalValue = valueHolder.getValue();
            Object convertedValue;
            if (valueHolder.isConverted()) {
                convertedValue = valueHolder.getConvertedValue();
                args.preparedArguments[paramIndex] = convertedValue;
            } else {
                MethodParameter methodParam = MethodParameter.forExecutable(executable, paramIndex);
                try {
                    convertedValue = converter.convertIfNecessary(originalValue, paramType, methodParam);
                } catch (TypeMismatchException ex) {
                    throw new UnsatisfiedDependencyException(mbd.getResourceDescription(), beanName,
                            new InjectionPoint(methodParam),
                            "Could not convert argument value of type ["
                                    + ObjectUtils.nullSafeClassName(valueHolder.getValue())
                                    + "] to required type [" + paramType.getName() + "]: " + ex.getMessage());
                }
                Object sourceHolder = valueHolder.getSource();
                if (sourceHolder instanceof ConstructorArgumentValues.ValueHolder) {
                    Object sourceValue = ((ConstructorArgumentValues.ValueHolder) sourceHolder).getValue();
                    args.resolveNecessary = true;
                    args.preparedArguments[paramIndex] = sourceValue;
                }
            }
            args.arguments[paramIndex] = convertedValue;
            args.rawArguments[paramIndex] = originalValue;
        } else {
            MethodParameter methodParam = MethodParameter.forExecutable(executable, paramIndex);
            // No explicit match found: we're either supposed to autowire or
            // have to fail creating an argument array for the given constructor.
            if (!autowiring) {
                throw new UnsatisfiedDependencyException(mbd.getResourceDescription(), beanName,
                        new InjectionPoint(methodParam),
                        "Ambiguous argument values for parameter of type [" + paramType.getName()
                                + "] - did you specify the correct bean references as arguments?");
            }
            try {
                Object autowiredArgument = resolveAutowiredArgument(methodParam, beanName, autowiredBeanNames,
                        converter, fallback);
                args.rawArguments[paramIndex] = autowiredArgument;
                args.arguments[paramIndex] = autowiredArgument;
                args.preparedArguments[paramIndex] = new AutowiredArgumentMarker();
                args.resolveNecessary = true;
            } catch (BeansException ex) {
                throw new UnsatisfiedDependencyException(mbd.getResourceDescription(), beanName,
                        new InjectionPoint(methodParam), ex);
            }
        }
    }

    for (String autowiredBeanName : autowiredBeanNames) {
        this.beanFactory.registerDependentBean(autowiredBeanName, beanName);
        if (logger.isDebugEnabled()) {
            logger.debug("Autowiring by type from bean name '" + beanName + "' via "
                    + (executable instanceof Constructor ? "constructor" : "factory method")
                    + " to bean named '" + autowiredBeanName + "'");
        }
    }

    return args;
}