SpringContext(8)-PropertyValue到Bean内部属性：BeanWrapper对象的setPropertyValues方法
解析出的PropertyValue，通过BeanWrapperImpl的父类AbstractPropertyAccessor的setPropertyValues方法来集成到Bean的属性中，该方法遍历PropertyValues内部的List，对每一个PropertyValue，调用setPropertyValue(PropertyValue pv)方法
java
@Override
public void setPropertyValue(PropertyValue pv) throws BeansException {
PropertyTokenHolder tokens = (PropertyTokenHolder) pv.resolvedTokens;
if (tokens == null) {
String propertyName = pv.getName();
AbstractNestablePropertyAccessor nestedPa;
try {
nestedPa = getPropertyAccessorForPropertyPath(propertyName);
}
catch (NotReadablePropertyException ex) {
throw new NotWritablePropertyException(getRootClass(), this.nestedPath + propertyName,
"Nested property in path '" + propertyName + "' does not exist", ex);
}
tokens = getPropertyNameTokens(getFinalPath(nestedPa, propertyName));
if (nestedPa == this) {
pv.getOriginalPropertyValue().resolvedTokens = tokens;
}
nestedPa.setPropertyValue(tokens, pv);
}
else {
setPropertyValue(tokens, pv);
}
}- 如果是非Tokenized的Property，则需要先按Property的Path来查找PropertyAccessor
- 获取对应的property name tokens，如果PropertyAccessor没有嵌套，则将获取到的Tokens放入propertyValue的resolvedTokens属性
- 如果没有Tokens则调用AbstractPropertyAccessor的
setPropertyValue(PropertyTokenHolder tokens, PropertyValue pv)方法，否则调用获取的PropertyAccessor的相同的方法
1.1 按Property的Path来查找PropertyAccessor
java
protected AbstractNestablePropertyAccessor getPropertyAccessorForPropertyPath(String propertyPath) {
int pos = PropertyAccessorUtils.getFirstNestedPropertySeparatorIndex(propertyPath);
// Handle nested properties recursively.
if (pos > -1) {
String nestedProperty = propertyPath.substring(0, pos);
String nestedPath = propertyPath.substring(pos + 1);
AbstractNestablePropertyAccessor nestedPa = getNestedPropertyAccessor(nestedProperty);
return nestedPa.getPropertyAccessorForPropertyPath(nestedPath);
}
else {
return this;
}
}- 返回第一个property separator(字符"."，忽略map key(如"map[a.b]"的情况)的位置，没有返回-1
- 如果确实PropertyPath有嵌套(上一步返回非-1),继续递归查找
- 如果确实PropertyPath没有嵌套，则返回当前的AbstractNestablePropertyAccessor
1.2 获取对应的property name tokens
返回一个PropertyTokenHolder对象，内部存储三个属性：以”a[b][c]"为例
- actualName：去掉所有key的值
"a" - canonicalName：
”a[b][c]" - keys：需要使用的toekn key，在示例中结果为
{"b","c"}
1.3 AbstractPropertyAccessor的setPropertyValue(PropertyTokenHolder tokens, PropertyValue pv)方法
java
protected void setPropertyValue(PropertyTokenHolder tokens, PropertyValue pv) throws BeansException {
if (tokens.keys != null) {
processKeyedProperty(tokens, pv);
}
else {
processLocalProperty(tokens, pv);
}
}根据Property的property name tokens中是否有keys，调用processKeyedProperty或者processLocalProperty
1.3.1 PropertyName有key:processKeyedProperty方法
1.3.2 PropertyName没有key:processLocalProperty方法
java
private void processLocalProperty(PropertyTokenHolder tokens, PropertyValue pv) {
PropertyHandler ph = getLocalPropertyHandler(tokens.actualName);
if (ph == null || !ph.isWritable()) {
if (pv.isOptional()) {
return;
}
else {
throw createNotWritablePropertyException(tokens.canonicalName);
}
}
Object oldValue = null;
try {
Object originalValue = pv.getValue();
Object valueToApply = originalValue;
if (!Boolean.FALSE.equals(pv.conversionNecessary)) {
if (pv.isConverted()) {
valueToApply = pv.getConvertedValue();
}
else {
if (isExtractOldValueForEditor() && ph.isReadable()) {
try {
oldValue = ph.getValue();
}
catch (Exception ex) {
if (ex instanceof PrivilegedActionException) {
ex = ((PrivilegedActionException) ex).getException();
}
}
}
valueToApply = convertForProperty(
tokens.canonicalName, oldValue, originalValue, ph.toTypeDescriptor());
}
pv.getOriginalPropertyValue().conversionNecessary = (valueToApply != originalValue);
}
ph.setValue(valueToApply);
}
catch (TypeMismatchException ex) {
throw ex;
}
catch (InvocationTargetException ex) {
PropertyChangeEvent propertyChangeEvent = new PropertyChangeEvent(
getRootInstance(), this.nestedPath + tokens.canonicalName, oldValue, pv.getValue());
if (ex.getTargetException() instanceof ClassCastException) {
throw new TypeMismatchException(propertyChangeEvent, ph.getPropertyType(), ex.getTargetException());
}
else {
Throwable cause = ex.getTargetException();
if (cause instanceof UndeclaredThrowableException) {
// May happen e.g. with Groovy-generated methods
cause = cause.getCause();
}
throw new MethodInvocationException(propertyChangeEvent, cause);
}
}
catch (Exception ex) {
PropertyChangeEvent pce = new PropertyChangeEvent(
getRootInstance(), this.nestedPath + tokens.canonicalName, oldValue, pv.getValue());
throw new MethodInvocationException(pce, ex);
}
}- 获取BeanPropertyHandler，如果返回null，或者Property不可写，则根据isOptional来决定直接返回还是抛出异常
- 判断是否需要convert，如果需要convert则将此属性缓存到pv的conversionNecessary属性中，同时，下面的set方法使用pv的convertedValue
- 调用PropertyHandler的setValue(value)方法，将值set到Bean里
1.3.2.1 获取BeanPropertyHandler
java
protected BeanPropertyHandler getLocalPropertyHandler(String propertyName) {
PropertyDescriptor pd = getCachedIntrospectionResults().getPropertyDescriptor(propertyName);
return (pd != null ? new BeanPropertyHandler(pd) : null);
}从BeanWrapperImpl实例的CachedIntrospectionResults中获取PropertyDescriptor，传入新的BeanPropertyHandler对象中返回此新对应，如果没有PropertyDescriptor，则返回null
1.3.2.2 最终执行Set过程：PropertyHandler的setValue(value)方法
java
@Override
public void setValue(final @Nullable Object value) throws Exception {
final Method writeMethod = (this.pd instanceof GenericTypeAwarePropertyDescriptor ?
((GenericTypeAwarePropertyDescriptor) this.pd).getWriteMethodForActualAccess() :
this.pd.getWriteMethod());
if (System.getSecurityManager() != null) {
AccessController.doPrivileged((PrivilegedAction<Object>) () -> {
ReflectionUtils.makeAccessible(writeMethod);
return null;
});
try {
AccessController.doPrivileged((PrivilegedExceptionAction<Object>) () ->
writeMethod.invoke(getWrappedInstance(), value), acc);
}
catch (PrivilegedActionException ex) {
throw ex.getException();
}
}
else {
ReflectionUtils.makeAccessible(writeMethod);
writeMethod.invoke(getWrappedInstance(), value);
}
}- 获取pd的WriteMethod
- 调用
writeMethod.invoke(getWrappedInstance(), value);来set值到Bean中
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