public class BeanDefinitionParserDelegate {
public static final String BEANS_NAMESPACE_URI = "http://www.springframework.org/schema/beans";
public static final String MULTI_VALUE_ATTRIBUTE_DELIMITERS = ",; ";
/** @deprecated as of Spring 3.1 in favor of {@link #MULTI_VALUE_ATTRIBUTE_DELIMITERS} */
public static final String BEAN_NAME_DELIMITERS = MULTI_VALUE_ATTRIBUTE_DELIMITERS;
public static final String TRUE_VALUE = "true";
public static final String FALSE_VALUE = "false";
public static final String DEFAULT_VALUE = "default";
public static final String DESCRIPTION_ELEMENT = "description";
public static final String AUTOWIRE_NO_VALUE = "no";
public static final String AUTOWIRE_BY_NAME_VALUE = "byName";
public static final String AUTOWIRE_BY_TYPE_VALUE = "byType";
public static final String AUTOWIRE_CONSTRUCTOR_VALUE = "constructor";
public static final String AUTOWIRE_AUTODETECT_VALUE = "autodetect";
public static final String DEPENDENCY_CHECK_ALL_ATTRIBUTE_VALUE = "all";
public static final String DEPENDENCY_CHECK_SIMPLE_ATTRIBUTE_VALUE = "simple";
public static final String DEPENDENCY_CHECK_OBJECTS_ATTRIBUTE_VALUE = "objects";
public static final String NAME_ATTRIBUTE = "name";
public static final String BEAN_ELEMENT = "bean";
public static final String META_ELEMENT = "meta";
public static final String ID_ATTRIBUTE = "id";
public static final String PARENT_ATTRIBUTE = "parent";
public static final String CLASS_ATTRIBUTE = "class";
public static final String ABSTRACT_ATTRIBUTE = "abstract";
public static final String SCOPE_ATTRIBUTE = "scope";
public static final String SINGLETON_ATTRIBUTE = "singleton";
public static final String LAZY_INIT_ATTRIBUTE = "lazy-init";
public static final String AUTOWIRE_ATTRIBUTE = "autowire";
public static final String AUTOWIRE_CANDIDATE_ATTRIBUTE = "autowire-candidate";
public static final String PRIMARY_ATTRIBUTE = "primary";
public static final String DEPENDENCY_CHECK_ATTRIBUTE = "dependency-check";
public static final String DEPENDS_ON_ATTRIBUTE = "depends-on";
public static final String INIT_METHOD_ATTRIBUTE = "init-method";
public static final String DESTROY_METHOD_ATTRIBUTE = "destroy-method";
public static final String FACTORY_METHOD_ATTRIBUTE = "factory-method";
public static final String FACTORY_BEAN_ATTRIBUTE = "factory-bean";
public static final String CONSTRUCTOR_ARG_ELEMENT = "constructor-arg";
public static final String INDEX_ATTRIBUTE = "index";
public static final String TYPE_ATTRIBUTE = "type";
public static final String VALUE_TYPE_ATTRIBUTE = "value-type";
public static final String KEY_TYPE_ATTRIBUTE = "key-type";
public static final String PROPERTY_ELEMENT = "property";
public static final String REF_ATTRIBUTE = "ref";
public static final String VALUE_ATTRIBUTE = "value";
public static final String LOOKUP_METHOD_ELEMENT = "lookup-method";
public static final String REPLACED_METHOD_ELEMENT = "replaced-method";
public static final String REPLACER_ATTRIBUTE = "replacer";
public static final String ARG_TYPE_ELEMENT = "arg-type";
public static final String ARG_TYPE_MATCH_ATTRIBUTE = "match";
public static final String REF_ELEMENT = "ref";
public static final String IDREF_ELEMENT = "idref";
public static final String BEAN_REF_ATTRIBUTE = "bean";
public static final String LOCAL_REF_ATTRIBUTE = "local";
public static final String PARENT_REF_ATTRIBUTE = "parent";
public static final String VALUE_ELEMENT = "value";
public static final String NULL_ELEMENT = "null";
public static final String ARRAY_ELEMENT = "array";
public static final String LIST_ELEMENT = "list";
public static final String SET_ELEMENT = "set";
public static final String MAP_ELEMENT = "map";
public static final String ENTRY_ELEMENT = "entry";
public static final String KEY_ELEMENT = "key";
public static final String KEY_ATTRIBUTE = "key";
public static final String KEY_REF_ATTRIBUTE = "key-ref";
public static final String VALUE_REF_ATTRIBUTE = "value-ref";
public static final String PROPS_ELEMENT = "props";
public static final String PROP_ELEMENT = "prop";
public static final String MERGE_ATTRIBUTE = "merge";
public static final String QUALIFIER_ELEMENT = "qualifier";
public static final String QUALIFIER_ATTRIBUTE_ELEMENT = "attribute";
public static final String DEFAULT_LAZY_INIT_ATTRIBUTE = "default-lazy-init";
public static final String DEFAULT_MERGE_ATTRIBUTE = "default-merge";
public static final String DEFAULT_AUTOWIRE_ATTRIBUTE = "default-autowire";
public static final String DEFAULT_DEPENDENCY_CHECK_ATTRIBUTE = "default-dependency-check";
public static final String DEFAULT_AUTOWIRE_CANDIDATES_ATTRIBUTE = "default-autowire-candidates";
public static final String DEFAULT_INIT_METHOD_ATTRIBUTE = "default-init-method";
public static final String DEFAULT_DESTROY_METHOD_ATTRIBUTE = "default-destroy-method";
protected final Log logger = LogFactory.getLog(getClass());
private final XmlReaderContext readerContext;
private final DocumentDefaultsDefinition defaults = new DocumentDefaultsDefinition();
private final ParseState parseState = new ParseState();
private Environment environment;
/**
*缓存所有已经解析的bean的id以及别名
*/
private final Set<String> usedNames = new HashSet<String>();
/**
* 使用给定的XmlReaderContext和Environment创建一个BeanDefinitionParserDelegate实例
*/
public BeanDefinitionParserDelegate(XmlReaderContext readerContext, Environment environment) {
Assert.notNull(readerContext, "XmlReaderContext must not be null");
Assert.notNull(readerContext, "Environment must not be null");
this.readerContext = readerContext;
this.environment = environment;
}
@Deprecated
public BeanDefinitionParserDelegate(XmlReaderContext readerContext) {
this(readerContext, new StandardEnvironment());
}
public final XmlReaderContext getReaderContext() {
return this.readerContext;
}
public final Environment getEnvironment() {
return this.environment;
}
protected Object extractSource(Element ele) {
return this.readerContext.extractSource(ele);
}
protected void error(String message, Node source) {
this.readerContext.error(message, source, this.parseState.snapshot());
}
protected void error(String message, Element source) {
this.readerContext.error(message, source, this.parseState.snapshot());
}
protected void error(String message, Element source, Throwable cause) {
this.readerContext.error(message, source, this.parseState.snapshot(), cause);
}
/**
*初始化默认值
*/
public void initDefaults(Element root, BeanDefinitionParserDelegate parent) {
populateDefaults(this.defaults, (parent != null ? parent.defaults : null), root);
this.readerContext.fireDefaultsRegistered(this.defaults);
}
/**
* 初始化默认值
*/
public void initDefaults(Element root) {
initDefaults(root, null);
}
/**
* 设置defualt数据，
*/
protected void populateDefaults(DocumentDefaultsDefinition defaults, DocumentDefaultsDefinition parentDefaults, Element root) {
//从根节点即<beans>节点中获取default-lazy-init参数
String lazyInit = root.getAttribute(DEFAULT_LAZY_INIT_ATTRIBUTE);
//如果lazyInit的值为default,如果parentDefaults不为null则侧其中获取lazyInit，否则设置为false
if (DEFAULT_VALUE.equals(lazyInit)) {
lazyInit = parentDefaults != null ? parentDefaults.getLazyInit() : FALSE_VALUE;
}
defaults.setLazyInit(lazyInit);
//获取default-merge属性
String merge = root.getAttribute(DEFAULT_MERGE_ATTRIBUTE);
if (DEFAULT_VALUE.equals(merge)) {
merge = parentDefaults != null ? parentDefaults.getMerge() : FALSE_VALUE;
}
defaults.setMerge(merge);
//获取default-autowire属性
String autowire = root.getAttribute(DEFAULT_AUTOWIRE_ATTRIBUTE);
if (DEFAULT_VALUE.equals(autowire)) {
autowire = parentDefaults != null ? parentDefaults.getAutowire() : AUTOWIRE_NO_VALUE;
}
defaults.setAutowire(autowire);
//设置defult-dependecny-check
defaults.setDependencyCheck(root.getAttribute(DEFAULT_DEPENDENCY_CHECK_ATTRIBUTE));
if (root.hasAttribute(DEFAULT_AUTOWIRE_CANDIDATES_ATTRIBUTE)) {
defaults.setAutowireCandidates(root.getAttribute(DEFAULT_AUTOWIRE_CANDIDATES_ATTRIBUTE));
}
else if (parentDefaults != null) {
defaults.setAutowireCandidates(parentDefaults.getAutowireCandidates());
}
if (root.hasAttribute(DEFAULT_INIT_METHOD_ATTRIBUTE)) {
defaults.setInitMethod(root.getAttribute(DEFAULT_INIT_METHOD_ATTRIBUTE));
}
else if (parentDefaults != null) {
defaults.setInitMethod(parentDefaults.getInitMethod());
}
if (root.hasAttribute(DEFAULT_DESTROY_METHOD_ATTRIBUTE)) {
defaults.setDestroyMethod(root.getAttribute(DEFAULT_DESTROY_METHOD_ATTRIBUTE));
}
else if (parentDefaults != null) {
defaults.setDestroyMethod(parentDefaults.getDestroyMethod());
}
defaults.setSource(this.readerContext.extractSource(root));
}
/**
* 获取默认值
*/
public DocumentDefaultsDefinition getDefaults() {
return this.defaults;
}
public BeanDefinitionDefaults getBeanDefinitionDefaults() {
BeanDefinitionDefaults bdd = new BeanDefinitionDefaults();
bdd.setLazyInit("TRUE".equalsIgnoreCase(this.defaults.getLazyInit()));
bdd.setDependencyCheck(this.getDependencyCheck(DEFAULT_VALUE));
bdd.setAutowireMode(this.getAutowireMode(DEFAULT_VALUE));
bdd.setInitMethodName(this.defaults.getInitMethod());
bdd.setDestroyMethodName(this.defaults.getDestroyMethod());
return bdd;
}
public String[] getAutowireCandidatePatterns() {
String candidatePattern = this.defaults.getAutowireCandidates();
return (candidatePattern != null ? StringUtils.commaDelimitedListToStringArray(candidatePattern) : null);
}
/**
* 解析<bean>节点，如果在解析过程中发生异常可能返回null
*/
public BeanDefinitionHolder parseBeanDefinitionElement(Element ele) {
return parseBeanDefinitionElement(ele, null);
}
/**
*/
public BeanDefinitionHolder parseBeanDefinitionElement(Element ele, BeanDefinition containingBean) {
//获取<bean>节点的id属性，如<bean id="man" ... />,则id=man
String id = ele.getAttribute(ID_ATTRIBUTE);
//获取name属性值
String nameAttr = ele.getAttribute(NAME_ATTRIBUTE);
List<String> aliases = new ArrayList<String>();
//如果name属性值不为空，拆分多个name,并保存到list中
if (StringUtils.hasLength(nameAttr)) {
String[] nameArr = StringUtils.tokenizeToStringArray(nameAttr, MULTI_VALUE_ATTRIBUTE_DELIMITERS);
aliases.addAll(Arrays.asList(nameArr));
}
//将id赋值给beanName
String beanName = id;
//如果beanName不为空且别名的列表不为空则将别名集合中的第一个值赋值为beanName
if (!StringUtils.hasText(beanName) && !aliases.isEmpty()) {
beanName = aliases.remove(0);
if (logger.isDebugEnabled()) {
logger.debug("No XML 'id' specified - using '" + beanName +
"' as bean name and " + aliases + " as aliases");
}
}
//beanName的唯一性检查,beanName和别名都不能和已有的bean id或别名重复
if (containingBean == null) {
checkNameUniqueness(beanName, aliases, ele);
}
// 如果当前bean 的id和别名都没有重复值则解析bean节点
AbstractBeanDefinition beanDefinition = parseBeanDefinitionElement(ele, beanName, containingBean);
if (beanDefinition != null) {
if (!StringUtils.hasText(beanName)) {
try {
if (containingBean != null) {
beanName = BeanDefinitionReaderUtils.generateBeanName(
beanDefinition, this.readerContext.getRegistry(), true);
}
else {
beanName = this.readerContext.generateBeanName(beanDefinition);
// Register an alias for the plain bean class name, if still possible,
// if the generator returned the class name plus a suffix.
// This is expected for Spring 1.2/2.0 backwards compatibility.
String beanClassName = beanDefinition.getBeanClassName();
if (beanClassName != null &&
beanName.startsWith(beanClassName) && beanName.length() > beanClassName.length() &&
!this.readerContext.getRegistry().isBeanNameInUse(beanClassName)) {
aliases.add(beanClassName);
}
}
if (logger.isDebugEnabled()) {
logger.debug("Neither XML 'id' nor 'name' specified - " +
"using generated bean name [" + beanName + "]");
}
}
catch (Exception ex) {
error(ex.getMessage(), ele);
return null;
}
}
String[] aliasesArray = StringUtils.toStringArray(aliases);
return new BeanDefinitionHolder(beanDefinition, beanName, aliasesArray);
}
return null;
}
/**
* 校验制定的bean的名称和别名在当前级别的beans嵌套内没有使用过
*/
protected void checkNameUniqueness(String beanName, List<String> aliases, Element beanElement) {
//定义一个找到的beanName,初始化值为null
String foundName = null;
//beanName不为空且userNames中包含这个beanName则将beanName赋值为foundName
if (StringUtils.hasText(beanName) && this.usedNames.contains(beanName)) {
foundName = beanName;
}
//如果foundName不为null,则判断usedNames中是否包含别名，将包含的第一个别名赋值给foundName
if (foundName == null) {
foundName = (String) CollectionUtils.findFirstMatch(this.usedNames, aliases);
}
//如果foundName不为null则进行错误处理
if (foundName != null) {
error("Bean name '" + foundName + "' is already used in this <beans> element", beanElement);
}
//向usedNames中添加beanName
this.usedNames.add(beanName);
//将aliases添加到usedNames
this.usedNames.addAll(aliases);
}
/**
* 解析Bean
*/
public AbstractBeanDefinition parseBeanDefinitionElement(
Element ele, String beanName, BeanDefinition containingBean) {
//使用beanName创建一个BeanEntriy对象并放入parseState中
this.parseState.push(new BeanEntry(beanName));
String className = null;
//如果bean节点中含有class属性，则将该获取该属性值
if (ele.hasAttribute(CLASS_ATTRIBUTE)) {
className = ele.getAttribute(CLASS_ATTRIBUTE).trim();
}
try {
// 如果bean节点含有parent属性则获取该属性
String parent = null;
if (ele.hasAttribute(PARENT_ATTRIBUTE)) {
parent = ele.getAttribute(PARENT_ATTRIBUTE);
}
//使用className和parent创建一个beanDefinition
AbstractBeanDefinition bd = createBeanDefinition(className, parent);
parseBeanDefinitionAttributes(ele, beanName, containingBean, bd);
//设置description
bd.setDescription(DomUtils.getChildElementValueByTagName(ele, DESCRIPTION_ELEMENT));
parseMetaElements(ele, bd);
//解析lookup-method元素
parseLookupOverrideSubElements(ele, bd.getMethodOverrides());
//解析 replace-method元素
parseReplacedMethodSubElements(ele, bd.getMethodOverrides());
//解析构造参数元素
parseConstructorArgElements(ele, bd);
//解析属性
parsePropertyElements(ele, bd);
parseQualifierElements(ele, bd);
bd.setResource(this.readerContext.getResource());
bd.setSource(extractSource(ele));
return bd;
}
catch (ClassNotFoundException ex) {
error("Bean class [" + className + "] not found", ele, ex);
}
catch (NoClassDefFoundError err) {
error("Class that bean class [" + className + "] depends on not found", ele, err);
}
catch (Throwable ex) {
error("Unexpected failure during bean definition parsing", ele, ex);
}
finally {
this.parseState.pop();
}
return null;
}
/**
* 解析给定的节点的属性值
*
*/
public AbstractBeanDefinition parseBeanDefinitionAttributes(Element ele, String beanName,
BeanDefinition containingBean, AbstractBeanDefinition bd) {
//如果bean节点含有scope属性则设置BeanDefinition的scope属性
if (ele.hasAttribute(SCOPE_ATTRIBUTE)) {
bd.setScope(ele.getAttribute(SCOPE_ATTRIBUTE));
//如果设置了scope属性同时设置了singleton，则进行错误处理！不允许同时设置scope和singleton
if (ele.hasAttribute(SINGLETON_ATTRIBUTE)) {
error("Specify either 'scope' or 'singleton', not both", ele);
}
}
else if (ele.hasAttribute(SINGLETON_ATTRIBUTE)) {
//如果bean节点中包含singletone属性且值为true，则设置scope属性为singleton否则设置为prototype
bd.setScope(TRUE_VALUE.equals(ele.getAttribute(SINGLETON_ATTRIBUTE)) ?
BeanDefinition.SCOPE_SINGLETON : BeanDefinition.SCOPE_PROTOTYPE);
}
else if (containingBean != null) {
// 如果含有内部bean则作用域以内部bean为准.
bd.setScope(containingBean.getScope());
}
//如果bean节点包含abstract值且值为true则设置beanDefinition的值为true否则设置为false
if (ele.hasAttribute(ABSTRACT_ATTRIBUTE)) {
bd.setAbstract(TRUE_VALUE.equals(ele.getAttribute(ABSTRACT_ATTRIBUTE)));
}
//获取lazy-init属性
String lazyInit = ele.getAttribute(LAZY_INIT_ATTRIBUTE);
//如果lazyInit的值等于default则使用beans根节点中设置的default-lazy-init值
if (DEFAULT_VALUE.equals(lazyInit)) {
lazyInit = this.defaults.getLazyInit();
}
bd.setLazyInit(TRUE_VALUE.equals(lazyInit));
//获取bean节点autowire属性值
String autowire = ele.getAttribute(AUTOWIRE_ATTRIBUTE);
//设置beanDefinition的AutowireMode
bd.setAutowireMode(getAutowireMode(autowire));
//获取dependency-check属性
String dependencyCheck = ele.getAttribute(DEPENDENCY_CHECK_ATTRIBUTE);
bd.setDependencyCheck(getDependencyCheck(dependencyCheck));
//如果bean节点中包含depends-on属性值
if (ele.hasAttribute(DEPENDS_ON_ATTRIBUTE)) {
//获取depends-on节点值
String dependsOn = ele.getAttribute(DEPENDS_ON_ATTRIBUTE);
//设置beandefinition的dependsOn属性
bd.setDependsOn(StringUtils.tokenizeToStringArray(dependsOn, MULTI_VALUE_ATTRIBUTE_DELIMITERS));
}
//获取autowire-candidate属性值
String autowireCandidate = ele.getAttribute(AUTOWIRE_CANDIDATE_ATTRIBUTE);
//如果autowireCandidate的值是空获取是default
if ("".equals(autowireCandidate) || DEFAULT_VALUE.equals(autowireCandidate)) {
//获取beans节点中设置的default-autowire-candidates属性值
String candidatePattern = this.defaults.getAutowireCandidates();
//如果candidatePattern不为null
if (candidatePattern != null) {
//将candidatePattern使用,分割为字符串数组
String[] patterns = StringUtils.commaDelimitedListToStringArray(candidatePattern);
//如果正则匹配beanName则设置为true否则设置为false
bd.setAutowireCandidate(PatternMatchUtils.simpleMatch(patterns, beanName));
}
}
else {
//如果没有设置autowire-candidate或者值不是false，如果其值是true则设置为true否则设置为false
bd.setAutowireCandidate(TRUE_VALUE.equals(autowireCandidate));
}
// 如果bean节点包含primary属性，则设置beanDefinition的primary属性
if (ele.hasAttribute(PRIMARY_ATTRIBUTE)) {
bd.setPrimary(TRUE_VALUE.equals(ele.getAttribute(PRIMARY_ATTRIBUTE)));
}
//如果bean节点中包含init-method属性
if (ele.hasAttribute(INIT_METHOD_ATTRIBUTE)) {
//获取init-method属性值
String initMethodName = ele.getAttribute(INIT_METHOD_ATTRIBUTE);
//如果initMethodName不是空字符串则设置initMethodName
if (!"".equals(initMethodName)) {
bd.setInitMethodName(initMethodName);
}
}
else {
//如果bean节点没有设置init-method，但是beans节点中设置了default-init-method
if (this.defaults.getInitMethod() != null) {
bd.setInitMethodName(this.defaults.getInitMethod());
bd.setEnforceInitMethod(false);
}
}
//如果bean节点中包含destory-method或者beans节点中设置了defult-destory-method属性则设置beanDefinition的destroyMethod
if (ele.hasAttribute(DESTROY_METHOD_ATTRIBUTE)) {
String destroyMethodName = ele.getAttribute(DESTROY_METHOD_ATTRIBUTE);
if (!"".equals(destroyMethodName)) {
bd.setDestroyMethodName(destroyMethodName);
}
}
else {
if (this.defaults.getDestroyMethod() != null) {
bd.setDestroyMethodName(this.defaults.getDestroyMethod());
bd.setEnforceDestroyMethod(false);
}
}
//如果bean节点中包含了factory-method，则设置beanDefinition的factoryMethod
if (ele.hasAttribute(FACTORY_METHOD_ATTRIBUTE)) {
bd.setFactoryMethodName(ele.getAttribute(FACTORY_METHOD_ATTRIBUTE));
}
//如果bean节点设置了factory-bean则设置beanDefinition的factoryBean
if (ele.hasAttribute(FACTORY_BEAN_ATTRIBUTE)) {
bd.setFactoryBeanName(ele.getAttribute(FACTORY_BEAN_ATTRIBUTE));
}
return bd;
}
/**
* 使用给定的类名称和父类名称创建一个BeanDifinition
*/
protected AbstractBeanDefinition createBeanDefinition(String className, String parentName)
throws ClassNotFoundException {
return BeanDefinitionReaderUtils.createBeanDefinition(
parentName, className, this.readerContext.getBeanClassLoader());
}
//解析Bean的元节点
public void parseMetaElements(Element ele, BeanMetadataAttributeAccessor attributeAccessor) {
//获取bean所有子节点
NodeList nl = ele.getChildNodes();
//遍历所有元节点
for (int i = 0; i < nl.getLength(); i++) {
Node node = nl.item(i);
/
if (isCandidateElement(node) && nodeNameEquals(node, META_ELEMENT)) {
// 强制类型转换
Element metaElement = (Element) node;
//获取key
String key = metaElement.getAttribute(KEY_ATTRIBUTE);
//获取value
String value = metaElement.getAttribute(VALUE_ATTRIBUTE);
//使用key,value构成一个元属性
BeanMetadataAttribute attribute = new BeanMetadataAttribute(key, value);
attribute.setSource(extractSource(metaElement));
attributeAccessor.addMetadataAttribute(attribute);
}
}
}
public int getAutowireMode(String attValue) {
String att = attValue;
if (DEFAULT_VALUE.equals(att)) {
att = this.defaults.getAutowire();
}
int autowire = AbstractBeanDefinition.AUTOWIRE_NO;
if (AUTOWIRE_BY_NAME_VALUE.equals(att)) {
autowire = AbstractBeanDefinition.AUTOWIRE_BY_NAME;
}
else if (AUTOWIRE_BY_TYPE_VALUE.equals(att)) {
autowire = AbstractBeanDefinition.AUTOWIRE_BY_TYPE;
}
else if (AUTOWIRE_CONSTRUCTOR_VALUE.equals(att)) {
autowire = AbstractBeanDefinition.AUTOWIRE_CONSTRUCTOR;
}
else if (AUTOWIRE_AUTODETECT_VALUE.equals(att)) {
autowire = AbstractBeanDefinition.AUTOWIRE_AUTODETECT;
}
// Else leave default value.
return autowire;
}
public int getDependencyCheck(String attValue) {
String att = attValue;
if (DEFAULT_VALUE.equals(att)) {
att = this.defaults.getDependencyCheck();
}
if (DEPENDENCY_CHECK_ALL_ATTRIBUTE_VALUE.equals(att)) {
return AbstractBeanDefinition.DEPENDENCY_CHECK_ALL;
}
else if (DEPENDENCY_CHECK_OBJECTS_ATTRIBUTE_VALUE.equals(att)) {
return AbstractBeanDefinition.DEPENDENCY_CHECK_OBJECTS;
}
else if (DEPENDENCY_CHECK_SIMPLE_ATTRIBUTE_VALUE.equals(att)) {
return AbstractBeanDefinition.DEPENDENCY_CHECK_SIMPLE;
}
else {
return AbstractBeanDefinition.DEPENDENCY_CHECK_NONE;
}
}
/**
* 解析构造参数元素
*/
public void parseConstructorArgElements(Element beanEle, BeanDefinition bd) {
NodeList nl = beanEle.getChildNodes();
for (int i = 0; i < nl.getLength(); i++) {
Node node = nl.item(i);
if (isCandidateElement(node) && nodeNameEquals(node, CONSTRUCTOR_ARG_ELEMENT)) {
parseConstructorArgElement((Element) node, bd);
}
}
}
/**
* 解析给定bean节点的属性元素
*/
public void parsePropertyElements(Element beanEle, BeanDefinition bd) {
NodeList nl = beanEle.getChildNodes();
for (int i = 0; i < nl.getLength(); i++) {
Node node = nl.item(i);
if (isCandidateElement(node) && nodeNameEquals(node, PROPERTY_ELEMENT)) {
parsePropertyElement((Element) node, bd);
}
}
}
/**
* 解析给定元素的 qualifier 子节点
*/
public void parseQualifierElements(Element beanEle, AbstractBeanDefinition bd) {
NodeList nl = beanEle.getChildNodes();
for (int i = 0; i < nl.getLength(); i++) {
Node node = nl.item(i);
if (isCandidateElement(node) && nodeNameEquals(node, QUALIFIER_ELEMENT)) {
parseQualifierElement((Element) node, bd);
}
}
}
/**
*解析给定节点的lookup-method子节点
*/
public void parseLookupOverrideSubElements(Element beanEle, MethodOverrides overrides) {
//获取bean节点的所有子节点
NodeList nl = beanEle.getChildNodes();
for (int i = 0; i < nl.getLength(); i++) {
Node node = nl.item(i);
//如果节点是lookup-method
if (isCandidateElement(node) && nodeNameEquals(node, LOOKUP_METHOD_ELEMENT)) {
Element ele = (Element) node;
String methodName = ele.getAttribute(NAME_ATTRIBUTE);
String beanRef = ele.getAttribute(BEAN_ELEMENT);
LookupOverride override = new LookupOverride(methodName, beanRef);
override.setSource(extractSource(ele));
overrides.addOverride(override);
}
}
}
/**
*
*/
public void parseReplacedMethodSubElements(Element beanEle, MethodOverrides overrides) {
NodeList nl = beanEle.getChildNodes();
for (int i = 0; i < nl.getLength(); i++) {
Node node = nl.item(i);
if (isCandidateElement(node) && nodeNameEquals(node, REPLACED_METHOD_ELEMENT)) {
Element replacedMethodEle = (Element) node;
String name = replacedMethodEle.getAttribute(NAME_ATTRIBUTE);
String callback = replacedMethodEle.getAttribute(REPLACER_ATTRIBUTE);
ReplaceOverride replaceOverride = new ReplaceOverride(name, callback);
// Look for arg-type match elements.
List<Element> argTypeEles = DomUtils.getChildElementsByTagName(replacedMethodEle, ARG_TYPE_ELEMENT);
for (Element argTypeEle : argTypeEles) {
String match = argTypeEle.getAttribute(ARG_TYPE_MATCH_ATTRIBUTE);
match = (StringUtils.hasText(match) ? match : DomUtils.getTextValue(argTypeEle));
if (StringUtils.hasText(match)) {
replaceOverride.addTypeIdentifier(match);
}
}
replaceOverride.setSource(extractSource(replacedMethodEle));
overrides.addOverride(replaceOverride);
}
}
}
/**
*
*/
public void parseConstructorArgElement(Element ele, BeanDefinition bd) {
String indexAttr = ele.getAttribute(INDEX_ATTRIBUTE);
String typeAttr = ele.getAttribute(TYPE_ATTRIBUTE);
String nameAttr = ele.getAttribute(NAME_ATTRIBUTE);
if (StringUtils.hasLength(indexAttr)) {
try {
int index = Integer.parseInt(indexAttr);
if (index < 0) {
error("'index' cannot be lower than 0", ele);
}
else {
try {
this.parseState.push(new ConstructorArgumentEntry(index));
Object value = parsePropertyValue(ele, bd, null);
ConstructorArgumentValues.ValueHolder valueHolder = new ConstructorArgumentValues.ValueHolder(value);
if (StringUtils.hasLength(typeAttr)) {
valueHolder.setType(typeAttr);
}
if (StringUtils.hasLength(nameAttr)) {
valueHolder.setName(nameAttr);
}
valueHolder.setSource(extractSource(ele));
if (bd.getConstructorArgumentValues().hasIndexedArgumentValue(index)) {
error("Ambiguous constructor-arg entries for index " + index, ele);
}
else {
bd.getConstructorArgumentValues().addIndexedArgumentValue(index, valueHolder);
}
}
finally {
this.parseState.pop();
}
}
}
catch (NumberFormatException ex) {
error("Attribute 'index' of tag 'constructor-arg' must be an integer", ele);
}
}
else {
try {
this.parseState.push(new ConstructorArgumentEntry());
Object value = parsePropertyValue(ele, bd, null);
ConstructorArgumentValues.ValueHolder valueHolder = new ConstructorArgumentValues.ValueHolder(value);
if (StringUtils.hasLength(typeAttr)) {
valueHolder.setType(typeAttr);
}
if (StringUtils.hasLength(nameAttr)) {
valueHolder.setName(nameAttr);
}
valueHolder.setSource(extractSource(ele));
bd.getConstructorArgumentValues().addGenericArgumentValue(valueHolder);
}
finally {
this.parseState.pop();
}
}
}
/**
*
*/
public void parsePropertyElement(Element ele, BeanDefinition bd) {
String propertyName = ele.getAttribute(NAME_ATTRIBUTE);
if (!StringUtils.hasLength(propertyName)) {
error("Tag 'property' must have a 'name' attribute", ele);
return;
}
this.parseState.push(new PropertyEntry(propertyName));
try {
if (bd.getPropertyValues().contains(propertyName)) {
error("Multiple 'property' definitions for property '" + propertyName + "'", ele);
return;
}
Object val = parsePropertyValue(ele, bd, propertyName);
PropertyValue pv = new PropertyValue(propertyName, val);
parseMetaElements(ele, pv);
pv.setSource(extractSource(ele));
bd.getPropertyValues().addPropertyValue(pv);
}
finally {
this.parseState.pop();
}
}
/**
*
*/
public void parseQualifierElement(Element ele, AbstractBeanDefinition bd) {
String typeName = ele.getAttribute(TYPE_ATTRIBUTE);
if (!StringUtils.hasLength(typeName)) {
error("Tag 'qualifier' must have a 'type' attribute", ele);
return;
}
this.parseState.push(new QualifierEntry(typeName));
try {
AutowireCandidateQualifier qualifier = new AutowireCandidateQualifier(typeName);
qualifier.setSource(extractSource(ele));
String value = ele.getAttribute(VALUE_ATTRIBUTE);
if (StringUtils.hasLength(value)) {
qualifier.setAttribute(AutowireCandidateQualifier.VALUE_KEY, value);
}
NodeList nl = ele.getChildNodes();
for (int i = 0; i < nl.getLength(); i++) {
Node node = nl.item(i);
if (isCandidateElement(node) && nodeNameEquals(node, QUALIFIER_ATTRIBUTE_ELEMENT)) {
Element attributeEle = (Element) node;
String attributeName = attributeEle.getAttribute(KEY_ATTRIBUTE);
String attributeValue = attributeEle.getAttribute(VALUE_ATTRIBUTE);
if (StringUtils.hasLength(attributeName) && StringUtils.hasLength(attributeValue)) {
BeanMetadataAttribute attribute = new BeanMetadataAttribute(attributeName, attributeValue);
attribute.setSource(extractSource(attributeEle));
qualifier.addMetadataAttribute(attribute);
}
else {
error("Qualifier 'attribute' tag must have a 'name' and 'value'", attributeEle);
return;
}
}
}
bd.addQualifier(qualifier);
}
finally {
this.parseState.pop();
}
}
/**
* 获取指定属性的值
*/
public Object parsePropertyValue(Element ele, BeanDefinition bd, String propertyName) {
String elementName = (propertyName != null) ?
"<property> element for property '" + propertyName + "'" :
"<constructor-arg> element";
// Should only have one child element: ref, value, list, etc.
NodeList nl = ele.getChildNodes();
Element subElement = null;
for (int i = 0; i < nl.getLength(); i++) {
Node node = nl.item(i);
if (node instanceof Element && !nodeNameEquals(node, DESCRIPTION_ELEMENT) &&
!nodeNameEquals(node, META_ELEMENT)) {
// Child element is what we're looking for.
if (subElement != null) {
error(elementName + " must not contain more than one sub-element", ele);
}
else {
subElement = (Element) node;
}
}
}
boolean hasRefAttribute = ele.hasAttribute(REF_ATTRIBUTE);
boolean hasValueAttribute = ele.hasAttribute(VALUE_ATTRIBUTE);
if ((hasRefAttribute && hasValueAttribute) ||
((hasRefAttribute || hasValueAttribute) && subElement != null)) {
error(elementName +
" is only allowed to contain either 'ref' attribute OR 'value' attribute OR sub-element", ele);
}
if (hasRefAttribute) {
String refName = ele.getAttribute(REF_ATTRIBUTE);
if (!StringUtils.hasText(refName)) {
error(elementName + " contains empty 'ref' attribute", ele);
}
RuntimeBeanReference ref = new RuntimeBeanReference(refName);
ref.setSource(extractSource(ele));
return ref;
}
else if (hasValueAttribute) {
TypedStringValue valueHolder = new TypedStringValue(ele.getAttribute(VALUE_ATTRIBUTE));
valueHolder.setSource(extractSource(ele));
return valueHolder;
}
else if (subElement != null) {
return parsePropertySubElement(subElement, bd);
}
else {
// Neither child element nor "ref" or "value" attribute found.
error(elementName + " must specify a ref or value", ele);
return null;
}
}
public Object parsePropertySubElement(Element ele, BeanDefinition bd) {
return parsePropertySubElement(ele, bd, null);
}
/**
*解析一个属性的子节点
*/
public Object parsePropertySubElement(Element ele, BeanDefinition bd, String defaultValueType) {
//如果子节点的命名空间是默认命名空间的
if (!isDefaultNamespace(ele)) {
return parseNestedCustomElement(ele, bd);
}
else if (nodeNameEquals(ele, BEAN_ELEMENT)) {
//如果子节点是bean则解析该bean配置
BeanDefinitionHolder nestedBd = parseBeanDefinitionElement(ele, bd);
if (nestedBd != null) {
nestedBd = decorateBeanDefinitionIfRequired(ele, nestedBd, bd);
}
//返回嵌套bean
return nestedBd;
}
else if (nodeNameEquals(ele, REF_ELEMENT)) {
//如果子节是ref,获取引用bean 名称
String refName = ele.getAttribute(BEAN_REF_ATTRIBUTE);
boolean toParent = false;
//如果引用bean名称为空
if (!StringUtils.hasLength(refName)) {
//获取local值
refName = ele.getAttribute(LOCAL_REF_ATTRIBUTE);
//如果local值为空
if (!StringUtils.hasLength(refName)) {
// 获取parent值
refName = ele.getAttribute(PARENT_REF_ATTRIBUTE);
toParent = true;
//如果parent值也为空则进行错误处理
if (!StringUtils.hasLength(refName)) {
error("'bean', 'local' or 'parent' is required for <ref> element", ele);
return null;
}
}
}
// 如果refName中不包含文字则进行错误处理
if (!StringUtils.hasText(refName)) {
error("<ref> element contains empty target attribute", ele);
return null;
}
//创建一个RuntimeBeanReference对象
RuntimeBeanReference ref = new RuntimeBeanReference(refName, toParent);
ref.setSource(extractSource(ele));
return ref;
}
else if (nodeNameEquals(ele, IDREF_ELEMENT)) {
//如果节点是idref
return parseIdRefElement(ele);
}
else if (nodeNameEquals(ele, VALUE_ELEMENT)) {
// 如果节点是value
return parseValueElement(ele, defaultValueType);
}
else if (nodeNameEquals(ele, NULL_ELEMENT)) {
//如果节点是null
TypedStringValue nullHolder = new TypedStringValue(null);
nullHolder.setSource(extractSource(ele));
return nullHolder;
}
else if (nodeNameEquals(ele, ARRAY_ELEMENT)) {
//如果节点是array
return parseArrayElement(ele, bd);
}
else if (nodeNameEquals(ele, LIST_ELEMENT)) {
//如果节点是list
return parseListElement(ele, bd);
}
else if (nodeNameEquals(ele, SET_ELEMENT)) {
//如果节点是set
return parseSetElement(ele, bd);
}
else if (nodeNameEquals(ele, MAP_ELEMENT)) {
//如果节点是map
return parseMapElement(ele, bd);
}
else if (nodeNameEquals(ele, PROPS_ELEMENT)) {
//如果节点是props
return parsePropsElement(ele);
}
else {
error("Unknown property sub-element: [" + ele.getNodeName() + "]", ele);
return null;
}
}
/**
*
*/
public Object parseIdRefElement(Element ele) {
// A generic reference to any name of any bean.
String refName = ele.getAttribute(BEAN_REF_ATTRIBUTE);
if (!StringUtils.hasLength(refName)) {
// A reference to the id of another bean in the same XML file.
refName = ele.getAttribute(LOCAL_REF_ATTRIBUTE);
if (!StringUtils.hasLength(refName)) {
error("Either 'bean' or 'local' is required for <idref> element", ele);
return null;
}
}
if (!StringUtils.hasText(refName)) {
error("<idref> element contains empty target attribute", ele);
return null;
}
RuntimeBeanNameReference ref = new RuntimeBeanNameReference(refName);
ref.setSource(extractSource(ele));
return ref;
}
/**
* Return a typed String value Object for the given value element.
*/
public Object parseValueElement(Element ele, String defaultTypeName) {
// It's a literal value.
String value = DomUtils.getTextValue(ele);
String specifiedTypeName = ele.getAttribute(TYPE_ATTRIBUTE);
String typeName = specifiedTypeName;
if (!StringUtils.hasText(typeName)) {
typeName = defaultTypeName;
}
try {
TypedStringValue typedValue = buildTypedStringValue(value, typeName);
typedValue.setSource(extractSource(ele));
typedValue.setSpecifiedTypeName(specifiedTypeName);
return typedValue;
}
catch (ClassNotFoundException ex) {
error("Type class [" + typeName + "] not found for <value> element", ele, ex);
return value;
}
}
/**
* 根据给定的值，已经类型创建一个TypedStringValue
*/
protected TypedStringValue buildTypedStringValue(String value, String targetTypeName)
throws ClassNotFoundException {
ClassLoader classLoader = this.readerContext.getBeanClassLoader();
TypedStringValue typedValue;
if (!StringUtils.hasText(targetTypeName)) {
typedValue = new TypedStringValue(value);
}
else if (classLoader != null) {
Class<?> targetType = ClassUtils.forName(targetTypeName, classLoader);
typedValue = new TypedStringValue(value, targetType);
}
else {
typedValue = new TypedStringValue(value, targetTypeName);
}
return typedValue;
}
/**
* 解析array节点
*/
public Object parseArrayElement(Element arrayEle, BeanDefinition bd) {
//获取value-type
String elementType = arrayEle.getAttribute(VALUE_TYPE_ATTRIBUTE);
//获取子节点
NodeList nl = arrayEle.getChildNodes();
//根据value-type和子节点长度创建一个ManagedArray
ManagedArray target = new ManagedArray(elementType, nl.getLength());
target.setSource(extractSource(arrayEle));
target.setElementTypeName(elementType);
target.setMergeEnabled(parseMergeAttribute(arrayEle));
parseCollectionElements(nl, target, bd, elementType);
return target;
}
/**
* Parse a list element.
*/
public List parseListElement(Element collectionEle, BeanDefinition bd) {
String defaultElementType = collectionEle.getAttribute(VALUE_TYPE_ATTRIBUTE);
NodeList nl = collectionEle.getChildNodes();
ManagedList<Object> target = new ManagedList<Object>(nl.getLength());
target.setSource(extractSource(collectionEle));
target.setElementTypeName(defaultElementType);
target.setMergeEnabled(parseMergeAttribute(collectionEle));
parseCollectionElements(nl, target, bd, defaultElementType);
return target;
}
/**
* Parse a set element.
*/
public Set parseSetElement(Element collectionEle, BeanDefinition bd) {
String defaultElementType = collectionEle.getAttribute(VALUE_TYPE_ATTRIBUTE);
NodeList nl = collectionEle.getChildNodes();
ManagedSet<Object> target = new ManagedSet<Object>(nl.getLength());
target.setSource(extractSource(collectionEle));
target.setElementTypeName(defaultElementType);
target.setMergeEnabled(parseMergeAttribute(collectionEle));
parseCollectionElements(nl, target, bd, defaultElementType);
return target;
}
protected void parseCollectionElements(
NodeList elementNodes, Collection<Object> target, BeanDefinition bd, String defaultElementType) {
//遍历子节点
for (int i = 0; i < elementNodes.getLength(); i++) {
Node node = elementNodes.item(i);
//如果节点是element且不是description则将其添加到target中
if (node instanceof Element && !nodeNameEquals(node, DESCRIPTION_ELEMENT)) {
target.add(parsePropertySubElement((Element) node, bd, defaultElementType));
}
}
}
/**
* 解析map节点
*/
public Map parseMapElement(Element mapEle, BeanDefinition bd) {
//获取key-type
String defaultKeyType = mapEle.getAttribute(KEY_TYPE_ATTRIBUTE);
//获取value-type
String defaultValueType = mapEle.getAttribute(VALUE_TYPE_ATTRIBUTE);
//获取map节点的所有entry子节点
List<Element> entryEles = DomUtils.getChildElementsByTagName(mapEle, ENTRY_ELEMENT);
//根据entry子节点的数量创建一个ManagedMap
ManagedMap<Object, Object> map = new ManagedMap<Object, Object>(entryEles.size());
map.setSource(extractSource(mapEle));
//设置KeyType
map.setKeyTypeName(defaultKeyType);
//设置valueType
map.setValueTypeName(defaultValueType);
map.setMergeEnabled(parseMergeAttribute(mapEle));
//遍历Entry
for (Element entryEle : entryEles) {
//获取entry的子节点
NodeList entrySubNodes = entryEle.getChildNodes();
Element keyEle = null;
Element valueEle = null;
//遍历entry子节点
for (int j = 0; j < entrySubNodes.getLength(); j++) {
Node node = entrySubNodes.item(j);
if (node instanceof Element) {
Element candidateEle = (Element) node;
if (nodeNameEquals(candidateEle, KEY_ELEMENT)) {
if (keyEle != null) {
error("<entry> element is only allowed to contain one <key> sub-element", entryEle);
}
else {
keyEle = candidateEle;
}
}
else {
// Child element is what we're looking for.
if (nodeNameEquals(candidateEle, DESCRIPTION_ELEMENT)) {
// the element is a <description> -> ignore it
}
else if (valueEle != null) {
error("<entry> element must not contain more than one value sub-element", entryEle);
}
else {
valueEle = candidateEle;
}
}
}
}
Object key = null;
//entry节点是否包含key属性
boolean hasKeyAttribute = entryEle.hasAttribute(KEY_ATTRIBUTE);
//entry节点是否包含key-ref属性
boolean hasKeyRefAttribute = entryEle.hasAttribute(KEY_REF_ATTRIBUTE);
//key,key-ref，或者key的子节点不能同时配置，
if ((hasKeyAttribute && hasKeyRefAttribute) ||
((hasKeyAttribute || hasKeyRefAttribute)) && keyEle != null) {
error("<entry> element is only allowed to contain either " +
"a 'key' attribute OR a 'key-ref' attribute OR a <key> sub-element", entryEle);
}
if (hasKeyAttribute) {
//如果含有key属性则更具key属性值创建一个TypedStringValue
key = buildTypedStringValueForMap(entryEle.getAttribute(KEY_ATTRIBUTE), defaultKeyType, entryEle);
}
else if (hasKeyRefAttribute) {
//如果含有key-ref且值不为空则创建一个RuntimeBaseReference
String refName = entryEle.getAttribute(KEY_REF_ATTRIBUTE);
if (!StringUtils.hasText(refName)) {
error("<entry> element contains empty 'key-ref' attribute", entryEle);
}
RuntimeBeanReference ref = new RuntimeBeanReference(refName);
ref.setSource(extractSource(entryEle));
key = ref;
}
else if (keyEle != null) {
key = parseKeyElement(keyEle, bd, defaultKeyType);
}
else {
error("<entry> element must specify a key", entryEle);
}
Object value = null;
boolean hasValueAttribute = entryEle.hasAttribute(VALUE_ATTRIBUTE);
boolean hasValueRefAttribute = entryEle.hasAttribute(VALUE_REF_ATTRIBUTE);
if ((hasValueAttribute && hasValueRefAttribute) ||
((hasValueAttribute || hasValueRefAttribute)) && valueEle != null) {
error("<entry> element is only allowed to contain either " +
"'value' attribute OR 'value-ref' attribute OR <value> sub-element", entryEle);
}
if (hasValueAttribute) {
//如果有value属性则根据value属性的值创建一个TypeStringValue
value = buildTypedStringValueForMap(entryEle.getAttribute(VALUE_ATTRIBUTE), defaultValueType, entryEle);
}
else if (hasValueRefAttribute) {
String refName = entryEle.getAttribute(VALUE_REF_ATTRIBUTE);
if (!StringUtils.hasText(refName)) {
error("<entry> element contains empty 'value-ref' attribute", entryEle);
}
RuntimeBeanReference ref = new RuntimeBeanReference(refName);
ref.setSource(extractSource(entryEle));
value = ref;
}
else if (valueEle != null) {
value = parsePropertySubElement(valueEle, bd, defaultValueType);
}
else {
error("<entry> element must specify a value", entryEle);
}
//向Map中添加数据
map.put(key, value);
}
return map;
}
/**
*创建一个TypedStringValue
*/
protected final Object buildTypedStringValueForMap(String value, String defaultTypeName, Element entryEle) {
try {
//创建一个TypeStringValue
TypedStringValue typedValue = buildTypedStringValue(value, defaultTypeName);
typedValue.setSource(extractSource(entryEle));
return typedValue;
}
catch (ClassNotFoundException ex) {
error("Type class [" + defaultTypeName + "] not found for Map key/value type", entryEle, ex);
return value;
}
}
/**
* 解析key的子节点
*/
protected Object parseKeyElement(Element keyEle, BeanDefinition bd, String defaultKeyTypeName) {
//获取key的所有子节点
NodeList nl = keyEle.getChildNodes();
Element subElement = null;
for (int i = 0; i < nl.getLength(); i++) {
Node node = nl.item(i);
if (node instanceof Element) {
// Child element is what we're looking for.
if (subElement != null) {
error("<key> element must not contain more than one value sub-element", keyEle);
}
else {
subElement = (Element) node;
}
}
}
return parsePropertySubElement(subElement, bd, defaultKeyTypeName);
}
/**
* Parse a props element.
*/
public Properties parsePropsElement(Element propsEle) {
ManagedProperties props = new ManagedProperties();
props.setSource(extractSource(propsEle));
props.setMergeEnabled(parseMergeAttribute(propsEle));
List<Element> propEles = DomUtils.getChildElementsByTagName(propsEle, PROP_ELEMENT);
for (Element propEle : propEles) {
String key = propEle.getAttribute(KEY_ATTRIBUTE);
// Trim the text value to avoid unwanted whitespace
// caused by typical XML formatting.
String value = DomUtils.getTextValue(propEle).trim();
TypedStringValue keyHolder = new TypedStringValue(key);
keyHolder.setSource(extractSource(propEle));
TypedStringValue valueHolder = new TypedStringValue(value);
valueHolder.setSource(extractSource(propEle));
props.put(keyHolder, valueHolder);
}
return props;
}
/**
* Parse the merge attribute of a collection element, if any.
*/
public boolean parseMergeAttribute(Element collectionElement) {
String value = collectionElement.getAttribute(MERGE_ATTRIBUTE);
if (DEFAULT_VALUE.equals(value)) {
value = this.defaults.getMerge();
}
return TRUE_VALUE.equals(value);
}
public BeanDefinition parseCustomElement(Element ele) {
return parseCustomElement(ele, null);
}
public BeanDefinition parseCustomElement(Element ele, BeanDefinition containingBd) {
String namespaceUri = getNamespaceURI(ele);
NamespaceHandler handler = this.readerContext.getNamespaceHandlerResolver().resolve(namespaceUri);
if (handler == null) {
error("Unable to locate Spring NamespaceHandler for XML schema namespace [" + namespaceUri + "]", ele);
return null;
}
return handler.parse(ele, new ParserContext(this.readerContext, this, containingBd));
}
/**
* 装饰BeanDefinition
**/
public BeanDefinitionHolder decorateBeanDefinitionIfRequired(Element ele, BeanDefinitionHolder definitionHolder) {
return decorateBeanDefinitionIfRequired(ele, definitionHolder, null);
}
public BeanDefinitionHolder decorateBeanDefinitionIfRequired(
Element ele, BeanDefinitionHolder definitionHolder, BeanDefinition containingBd) {
BeanDefinitionHolder finalDefinition = definitionHolder;
// 获取节点的所有属性，[autowire,autowire-candidate,class,id,lazy-init]
NamedNodeMap attributes = ele.getAttributes();
//遍历属性
for (int i = 0; i < attributes.getLength(); i++) {
// autowire
Node node = attributes.item(i);
finalDefinition = decorateIfRequired(node, finalDefinition, containingBd);
}
NodeList children = ele.getChildNodes();
for (int i = 0; i < children.getLength(); i++) {
Node node = children.item(i);
if (node.getNodeType() == Node.ELEMENT_NODE) {
finalDefinition = decorateIfRequired(node, finalDefinition, containingBd);
}
}
return finalDefinition;
}
private BeanDefinitionHolder decorateIfRequired(
Node node, BeanDefinitionHolder originalDef, BeanDefinition containingBd) {
//获取节点的命名空间,null
String namespaceUri = getNamespaceURI(node);
//如果命名空间不是默认的命名空间
if (!isDefaultNamespace(namespaceUri)) {
//获取命名空间处理器
NamespaceHandler handler = this.readerContext.getNamespaceHandlerResolver().resolve(namespaceUri);
if (handler != null) {
return handler.decorate(node, originalDef, new ParserContext(this.readerContext, this, containingBd));
}
else if (namespaceUri != null && namespaceUri.startsWith("http://www.springframework.org/")) {
error("Unable to locate Spring NamespaceHandler for XML schema namespace [" + namespaceUri + "]", node);
}
else {
// A custom namespace, not to be handled by Spring - maybe "xml:...".
if (logger.isDebugEnabled()) {
logger.debug("No Spring NamespaceHandler found for XML schema namespace [" + namespaceUri + "]");
}
}
}
return originalDef;
}
private BeanDefinitionHolder parseNestedCustomElement(Element ele, BeanDefinition containingBd) {
BeanDefinition innerDefinition = parseCustomElement(ele, containingBd);
if (innerDefinition == null) {
error("Incorrect usage of element '" + ele.getNodeName() + "' in a nested manner. " +
"This tag cannot be used nested inside <property>.", ele);
return null;
}
String id = ele.getNodeName() + BeanDefinitionReaderUtils.GENERATED_BEAN_NAME_SEPARATOR +
ObjectUtils.getIdentityHexString(innerDefinition);
if (logger.isDebugEnabled()) {
logger.debug("Using generated bean name [" + id +
"] for nested custom element '" + ele.getNodeName() + "'");
}
return new BeanDefinitionHolder(innerDefinition, id);
}
/**
*获取指定节点的NamespaceURI
*/
public String getNamespaceURI(Node node) {
return node.getNamespaceURI();
}
public String getLocalName(Node node) {
return node.getLocalName();
}
public boolean nodeNameEquals(Node node, String desiredName) {
return desiredName.equals(node.getNodeName()) || desiredName.equals(getLocalName(node));
}
/**
* 如果给定的namespaceUri不为空且等于http://www.springframework.org/schema/beans 则是默认的命名空间
**/
public boolean isDefaultNamespace(String namespaceUri) {
return (!StringUtils.hasLength(namespaceUri) || BEANS_NAMESPACE_URI.equals(namespaceUri));
}
/**
* 判断给定的节点的namespaceUri是不是默认的命名空间值
**/
public boolean isDefaultNamespace(Node node) {
return isDefaultNamespace(getNamespaceURI(node));
}
private boolean isCandidateElement(Node node) {
return (node instanceof Element && (isDefaultNamespace(node) || !isDefaultNamespace(node.getParentNode())));
}
}