http://xml.apache.org/commons/components/external/: xml-commons provides an Apache-hosted set of DOM, SAX, and JAXP interfaces for use in other xml-based projects. Our hope is that we can standardize on both a common version and packaging scheme for these critical XML standards interfaces to make the lives of both our developers and users easier. The External Components portion of xml-commons contains interfaces that are defined by external standards organizations. For DOM, that's the W3C; for SAX it's David Megginson and sax.sourceforge.net; for JAXP it's Sun. 
public interface javax.xml.stream.XMLResolver
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: javax.xml.stream.XMLResolver
  super_class: java.lang.Object
{
  public abstract java.lang.Object resolveEntity(java.lang.String, java.lang.String, java.lang.String, java.lang.String);
    descriptor: (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Exceptions:
      throws javax.xml.stream.XMLStreamException
    MethodParameters:
           Name  Flags
      publicID   
      systemID   
      baseURI    
      namespace  
}
SourceFile: "XMLResolver.java"