import com.sun.xml.internal.bind.v2.util.TypeCast; //导入依赖的package包/类
/**
 * The API will invoke this method via reflection
 */
public static JAXBContext createContext( Class[] classes, Map<String,Object> properties ) throws JAXBException {
    // fool-proof check, and copy the map to make it easier to find unrecognized properties.
    if(properties==null)
        properties = Collections.emptyMap();
    else
        properties = new HashMap<String,Object>(properties);

    String defaultNsUri = getPropertyValue(properties,JAXBRIContext.DEFAULT_NAMESPACE_REMAP,String.class);

    Boolean c14nSupport = getPropertyValue(properties,JAXBRIContext.CANONICALIZATION_SUPPORT,Boolean.class);
    if(c14nSupport==null)
        c14nSupport = false;

    Boolean allNillable = getPropertyValue(properties,JAXBRIContext.TREAT_EVERYTHING_NILLABLE,Boolean.class);
    if(allNillable==null)
        allNillable = false;

    Boolean retainPropertyInfo = getPropertyValue(properties, JAXBRIContext.RETAIN_REFERENCE_TO_INFO, Boolean.class);
    if(retainPropertyInfo==null)
        retainPropertyInfo = false;

    Boolean supressAccessorWarnings = getPropertyValue(properties, JAXBRIContext.SUPRESS_ACCESSOR_WARNINGS, Boolean.class);
    if(supressAccessorWarnings==null)
        supressAccessorWarnings = false;

    Boolean improvedXsiTypeHandling = getPropertyValue(properties, JAXBRIContext.IMPROVED_XSI_TYPE_HANDLING, Boolean.class);
    if(improvedXsiTypeHandling == null)
        improvedXsiTypeHandling = true;

    Boolean xmlAccessorFactorySupport = getPropertyValue(properties,
       JAXBRIContext.XMLACCESSORFACTORY_SUPPORT,Boolean.class);
    if(xmlAccessorFactorySupport==null){
        xmlAccessorFactorySupport = false;
        Util.getClassLogger().log(Level.FINE, "Property " +
            JAXBRIContext.XMLACCESSORFACTORY_SUPPORT +
            "is not active.  Using JAXB's implementation");
    }

    RuntimeAnnotationReader ar = getPropertyValue(properties,JAXBRIContext.ANNOTATION_READER,RuntimeAnnotationReader.class);

    Map<Class,Class> subclassReplacements;
    try {
        subclassReplacements = TypeCast.checkedCast(
            getPropertyValue(properties, JAXBRIContext.SUBCLASS_REPLACEMENTS, Map.class), Class.class, Class.class);
    } catch (ClassCastException e) {
        throw new JAXBException(Messages.INVALID_TYPE_IN_MAP.format(),e);
    }

    if(!properties.isEmpty()) {
        throw new JAXBException(Messages.UNSUPPORTED_PROPERTY.format(properties.keySet().iterator().next()));
    }

    JAXBContextImpl.JAXBContextBuilder builder = new JAXBContextImpl.JAXBContextBuilder();
    builder.setClasses(classes);
    builder.setTypeRefs(Collections.<TypeReference>emptyList());
    builder.setSubclassReplacements(subclassReplacements);
    builder.setDefaultNsUri(defaultNsUri);
    builder.setC14NSupport(c14nSupport);
    builder.setAnnotationReader(ar);
    builder.setXmlAccessorFactorySupport(xmlAccessorFactorySupport);
    builder.setAllNillable(allNillable);
    builder.setRetainPropertyInfo(retainPropertyInfo);
    builder.setSupressAccessorWarnings(supressAccessorWarnings);
    builder.setImprovedXsiTypeHandling(improvedXsiTypeHandling);
    return builder.build();
}