001 /* 002 * @(#)$Id: JAXBResult.java,v 1.8 2003/01/13 21:15:52 ryans Exp $ 003 * 004 * Copyright 2002 Sun Microsystems, Inc. All Rights Reserved. 005 * 006 * This software is the proprietary information of Sun Microsystems, Inc. 007 * Use is subject to license terms. 008 * 009 */ 010 package javax.xml.bind.util; 011 012 import javax.xml.bind.JAXBContext; 013 import javax.xml.bind.JAXBException; 014 import javax.xml.bind.Unmarshaller; 015 import javax.xml.bind.UnmarshallerHandler; 016 import javax.xml.transform.sax.SAXResult; 017 018 /** 019 * JAXP {@link javax.xml.transform.Result} implementation 020 * that unmarshals a JAXB object. 021 * 022 * <p> 023 * This utility class is useful to combine JAXB with 024 * other Java/XML technologies. 025 * 026 * <p> 027 * The following example shows how to use JAXB to unmarshal a document 028 * resulting from an XSLT transformation. 029 * 030 * <blockquote> 031 * <pre> 032 * JAXBResult result = new JAXBResult( 033 * JAXBContext.newInstance("org.acme.foo") ); 034 * 035 * // set up XSLT transformation 036 * TransformerFactory tf = TransformerFactory.newInstance(); 037 * Transformer t = tf.newTransformer(new StreamSource("test.xsl")); 038 * 039 * // run transformation 040 * t.transform(new StreamSource("document.xml"),result); 041 * 042 * // obtain the unmarshalled content tree 043 * Object o = result.getReult(); 044 * </pre> 045 * </blockquote> 046 * 047 * @author 048 * Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com) 049 */ 050 public class JAXBResult extends SAXResult { 051 052 /** 053 * Creates a new instance that uses the specified 054 * JAXBContext to unmarshal. 055 * 056 * @param context The JAXBContext that will be used to create the 057 * necessary Unmarshaller. This parameter must not be null. 058 * @exception JAXBException if an error is encountered while creating the 059 * JAXBResult or if the context parameter is null. 060 */ 061 public JAXBResult( JAXBContext context ) throws JAXBException { 062 this( ( context == null ) ? assertionFailed() : context.createUnmarshaller() ); 063 } 064 065 /** 066 * Creates a new instance that uses the specified 067 * Unmarshaler to unmarshal an object. 068 * 069 * <p> 070 * This JAXBResult object will use the specified Unmarshaller 071 * instance. It is the caller's responsibility not to use the 072 * same Unmarshaller for other purposes while it is being 073 * used by this object. 074 * 075 * <p> 076 * The primary purpose of this method is to allow the client 077 * to configure Unmarshaller. Unless you know what you are doing, 078 * it's easier and safer to pass a JAXBContext. 079 * 080 * @param _unmarshaller the unmarshaller. This parameter must not be null. 081 * @throws JAXBException if an error is encountered while creating the 082 * JAXBResult or the Unmarshaller parameter is null. 083 */ 084 public JAXBResult( Unmarshaller _unmarshaller ) throws JAXBException { 085 if( _unmarshaller == null ) 086 throw new JAXBException( 087 Messages.format( Messages.RESULT_NULL_UNMARSHALLER ) ); 088 089 this.unmarshallerHandler = _unmarshaller.getUnmarshallerHandler(); 090 091 super.setHandler(unmarshallerHandler); 092 } 093 094 /** 095 * Unmarshaller that will be used to unmarshal 096 * the input documents. 097 */ 098 private final UnmarshallerHandler unmarshallerHandler; 099 100 /** 101 * Gets the unmarshalled object created by the transformation. 102 * 103 * @return 104 * Always return a non-null object. 105 * 106 * @exception IllegalStateException 107 * if this method is called before an object is unmarshalled. 108 * 109 * @exception JAXBException 110 * if there is any unmarshalling error. 111 * Note that the implementation is allowed to throw SAXException 112 * during the parsing when it finds an error. 113 */ 114 public Object getResult() throws JAXBException { 115 return unmarshallerHandler.getResult(); 116 } 117 118 /** 119 * Hook to throw exception from the middle of a contructor chained call 120 * to this 121 */ 122 private static Unmarshaller assertionFailed() throws JAXBException { 123 throw new JAXBException( Messages.format( Messages.RESULT_NULL_CONTEXT ) ); 124 } 125 }