public BeanWrapper autowireConstructor( final String beanName, final RootBeanDefinition mbd, Constructor<?>[] chosenCtors, final Object[] explicitArgs) { BeanWrapperImpl bw = new BeanWrapperImpl(); this.beanFactory.initBeanWrapper(bw); Constructor<?> constructorToUse = null; ArgumentsHolder argsHolderToUse = null; Object[] argsToUse = null; if (explicitArgs != null) { argsToUse = explicitArgs; } else { Object[] argsToResolve = null; synchronized (mbd.constructorArgumentLock) { constructorToUse = (Constructor<?>) mbd.resolvedConstructorOrFactoryMethod; if (constructorToUse != null && mbd.constructorArgumentsResolved) { // Found a ***d constructor... argsToUse = mbd.resolvedConstructorArguments; if (argsToUse == null) { argsToResolve = mbd.preparedConstructorArguments; } } } if (argsToResolve != null) { argsToUse = resolvePreparedArguments(beanName, mbd, bw, constructorToUse, argsToResolve); } } if (constructorToUse == null) { // Need to resolve the constructor. boolean autowiring = (chosenCtors != null || mbd.getResolvedAutowireMode() == RootBeanDefinition.AUTOWIRE_CONSTRUCTOR); ConstructorArgumentValues resolvedValues = null; int minNrOfArgs; if (explicitArgs != null) { minNrOfArgs = explicitArgs.length; } else { ConstructorArgumentValues cargs = mbd.getConstructorArgumentValues(); resolvedValues = new ConstructorArgumentValues(); minNrOfArgs = resolveConstructorArguments(beanName, mbd, bw, cargs, resolvedValues); } // Take specified constructors, if any. Constructor<?>[] candidates = chosenCtors; if (candidates == null) { Class<?> beanClass = mbd.getBeanClass(); try { candidates = (mbd.isNonPublicAccessAllowed() ? beanClass.getDeclaredConstructors() : beanClass.getConstructors()); } catch (Throwable ex) { throw new BeanCreationException(mbd.getResourceDescription(), beanName, "Resolution of declared constructors on bean Class [" + beanClass.getName() + "] from ClassLoader [" + beanClass.getClassLoader() + "] failed", ex); } } AutowireUtils.sortConstructors(candidates); int minTypeDiffWeight = Integer.MAX_VALUE; Set<Constructor<?>> ambiguousConstructors = null; List<Exception> causes = null; for (int i = 0; i < candidates.length; i++) { Constructor<?> candidate = candidates[i]; Class<?>[] paramTypes = candidate.getParameterTypes(); if (constructorToUse != null && argsToUse.length > paramTypes.length) { // Already found greedy constructor that can be satisfied -> // do not look any further, there are only less greedy constructors left. break; } if (paramTypes.length < minNrOfArgs) { continue; } ArgumentsHolder argsHolder; if (resolvedValues != null) { try { String[] paramNames = ConstructorPropertiesChecker.evaluate(candidate, paramTypes.length); if (paramNames == null) { ParameterNameDiscoverer pnd = this.beanFactory.getParameterNameDiscoverer(); if (pnd != null) { paramNames = pnd.getParameterNames(candidate); } } argsHolder = createArgumentArray( beanName, mbd, resolvedValues, bw, paramTypes, paramNames, candidate, autowiring); } catch (UnsatisfiedDependencyException ex) { if (this.beanFactory.logger.isTraceEnabled()) { this.beanFactory.logger.trace( "Ignoring constructor [" + candidate + "] of bean '" + beanName + "': " + ex); } if (i == candidates.length - 1 && constructorToUse == null) { if (causes != null) { for (Exception cause : causes) { this.beanFactory.onSuppressedException(cause); } } throw ex; } else { // Swallow and try next constructor. if (causes == null) { causes = new LinkedList<Exception>(); } causes.add(ex); continue; } } } else { // Explicit arguments given -> arguments length must match exactly. if (paramTypes.length != explicitArgs.length) { continue; } argsHolder = new ArgumentsHolder(explicitArgs); } int typeDiffWeight = (mbd.isLenientConstructorResolution() ? argsHolder.getTypeDifferenceWeight(paramTypes) : argsHolder.getAssignabilityWeight(paramTypes)); // Choose this constructor if it represents the closest match. if (typeDiffWeight < minTypeDiffWeight) { constructorToUse = candidate; argsHolderToUse = argsHolder; argsToUse = argsHolder.arguments; minTypeDiffWeight = typeDiffWeight; ambiguousConstructors = null; } else if (constructorToUse != null && typeDiffWeight == minTypeDiffWeight) { if (ambiguousConstructors == null) { ambiguousConstructors = new LinkedHashSet<Constructor<?>>(); ambiguousConstructors.add(constructorToUse); } ambiguousConstructors.add(candidate); } } if (constructorToUse == null) { throw new BeanCreationException(mbd.getResourceDescription(), beanName, "Could not resolve matching constructor " + "(hint: specify index/type/name arguments for simple parameters to avoid type ambiguities)"); } else if (ambiguousConstructors != null && !mbd.isLenientConstructorResolution()) { throw new BeanCreationException(mbd.getResourceDescription(), beanName, "Ambiguous constructor matches found in bean '" + beanName + "' " + "(hint: specify index/type/name arguments for simple parameters to avoid type ambiguities): " + ambiguousConstructors); } if (explicitArgs == null) { argsHolderToUse.storeCache(mbd, constructorToUse); } } try { Object beanInstance; if (System.getSecurityManager() != null) { final Constructor<?> ctorToUse = constructorToUse; final Object[] argumentsToUse = argsToUse; beanInstance = AccessController.doPrivileged(new PrivilegedAction<Object>() { @Override public Object run() { return beanFactory.getInstantiationStrategy().instantiate( mbd, beanName, beanFactory, ctorToUse, argumentsToUse); } }, beanFactory.getAccessControlContext()); } else { beanInstance = this.beanFactory.getInstantiationStrategy().instantiate( mbd, beanName, this.beanFactory, constructorToUse, argsToUse); } bw.setWrappedInstance(beanInstance); return bw; } catch (Throwable ex) { throw new BeanCreationException(mbd.getResourceDescription(), beanName, "Instantiation of bean failed", ex); } }这段先是调用构造方法,然后再进行setter
public class TestBean {
private String name;
private int age;
public TestBean()
{
System.out.println("TestBean - -- -no Param");
}
public TestBean(String name)
{
System.out.println("=================" + name + "=================");
this.name = name;
}
public void setAge(int age) {
System.out.println("设置age");
this.age = age;
}
} <bean id="testBean" class="TestBean">
<constructor-arg name="name" value="adea"></constructor-arg>
<property name="age" value="12"></property>
</bean>