是的。自动加载、解析。
我们可以看一下 spring-beans-xxx.jar 中的对象工厂中 PluggableSchemaResolver 关于此的一些源码片段：
/***
* Loads the schema URL -> schema file location mappings using the default
* mapping file pattern "META-INF/spring.schemas".
* @param classLoader the ClassLoader to use for loading
* (can be <code>null</code>) to use the default ClassLoader)
* @see PropertiesLoaderUtils#loadAllProperties(String, ClassLoader)
*/
public PluggableSchemaResolver(ClassLoader classLoader) {
this.classLoader = classLoader;
this.schemaMappingsLocation = DEFAULT_SCHEMA_MAPPINGS_LOCATION;
}
/***
* Loads the schema URL -> schema file location mappings using the given
* mapping file pattern.
* @param classLoader the ClassLoader to use for loading
* (can be <code>null</code>) to use the default ClassLoader)
* @param schemaMappingsLocation the location of the file that defines schema mappings
* (must not be empty)
* @see PropertiesLoaderUtils#loadAllProperties(String, ClassLoader)
*/
public PluggableSchemaResolver(ClassLoader classLoader, String schemaMappingsLocation) {
Assert.hasText(schemaMappingsLocation, "'schemaMappingsLocation' must not be empty");
this.classLoader = classLoader;
this.schemaMappingsLocation = schemaMappingsLocation;
}
public InputSource resolveEntity(String publicId, String systemId) throws IOException {
if (logger.isTraceEnabled()) {
logger.trace("Trying to resolve XML entity with public id [" + publicId +
"] and system id [" + systemId + "]");
}
if (systemId != null) {
String resourceLocation = getSchemaMappings().get(systemId);
if (resourceLocation != null) {
Resource resource = new ClassPathResource(resourceLocation, this.classLoader);
try {
InputSource source = new InputSource(resource.getInputStream());
source.setPublicId(publicId);
source.setSystemId(systemId);
if (logger.isDebugEnabled()) {
logger.debug("Found XML schema [" + systemId + "] in classpath: " + resourceLocation);
}
return source;
}
catch (FileNotFoundException ex) {
if (logger.isDebugEnabled()) {
logger.debug("Couldn't find XML schema [" + systemId + "]: " + resource, ex);
}
}
}
}
return null;
}
/***
* Load the specified schema mappings lazily.
*/
private Map<String, String> getSchemaMappings() {
if (this.schemaMappings == null) {
synchronized (this) {
if (this.schemaMappings == null) {
if (logger.isDebugEnabled()) {
logger.debug("Loading schema mappings from [" + this.schemaMappingsLocation + "]");
}
try {
Properties mappings =
PropertiesLoaderUtils.loadAllProperties(this.schemaMappingsLocation, this.classLoader);
if (logger.isDebugEnabled()) {
logger.debug("Loaded schema mappings: " + mappings);
}
Map<String, String> schemaMappings = new ConcurrentHashMap<String, String>();
CollectionUtils.mergePropertiesIntoMap(mappings, schemaMappings);
this.schemaMappings = schemaMappings;
}
catch (IOException ex) {
throw new IllegalStateException(
"Unable to load schema mappings from location [" + this.schemaMappingsLocation + "]", ex);
}
}
}
}
return this.schemaMappings;
}
另，spring4 不了解，不做解释。
官网提供的肯定有文档。
