{"id":2186,"date":"2011-05-12T23:16:06","date_gmt":"2011-05-13T04:16:06","guid":{"rendered":"http:\/\/jianmingli.com\/wp\/?p=2186"},"modified":"2011-05-12T23:16:06","modified_gmt":"2011-05-13T04:16:06","slug":"jaxb-2-0","status":"publish","type":"post","link":"https:\/\/jianmingli.com\/wp\/?p=2186","title":{"rendered":"JAXB 2.0"},"content":{"rendered":"

Overview<\/h2><\/span>\n

* JAXB = Java Architecture <\/strong>for XML Binding.
\n* Reference implementation is available at http:\/\/jaxb.java.net\/<\/a>
\n* JAXB 2.0 is part of
\n– J2EE 5
\n– JDK 6
\n* JAXB 2.0 requires
\n– JDK 1.5<\/p>\n

JAXB 2.0 vs JAXB 1.0<\/h3><\/span>\n

* Schema compiler generates annotated POJOs instead of separate interface and implementation classes for each component of an XML schema.
\n* Any Java class can be bound to an XML representation via annotations.
\n* All generated classes are portable among different implementations. In JAXB 1.0, only interfaces are portable.
\n* JAXB 2.0 does not include validation capabilities. Validation is delegated to JAXP 1.3.
\n* JAXB 2.0 has complete support for W3C XML Schema. JAXB 1.0 not.
\n* Integration with StAX to support <\/p>\n

javax.xml. stream. XMLStreamWriter\r\njavax.xml.stream.XMLStreamReader\r\njavax.xml.stream.XMLEventWriter\r\njavax.xml.stream.XMLEventReader\r\n<\/pre>\n
* JAXB 2.0 supports callback methods for Marshaller and Unmarshaller objects.<\/p>\n
Data Binding: XML <-> Java<\/h3><\/span>\n
* A data binding facility contains:
\n– schema compiler: xml -> Java
\n– schema generator: Java -> xml
\n* A data binding framework (i.e. runtime API) supports:
\n– unmarshalling: xml -> Java
\n– marshalling: Java -> xml
\n– binding is done via a binder: XML schema <-> JAXB classes<\/p>\n
Goals<\/h3><\/span>\n
* Full XML Schema support
\n* Allow binding existing Java classes to generated XML schema, i.e. support from Java approach
\n* Full JAX-WS 2.0 data binding support
\n* Support container managed environments
\n* Support schema evolution
\n* Application specific behavior
\n* Support partial mapping of XML document
\n* Clarify integration with StAX (Streaming API for XML)
\n* Clarify relationship to other XML related specs
\n* JAXB mapped classes should be portable
\n* Support round trippings,
\n– Java -> xml -> Java
\n– xml -> Java -> xml
\n* Support unmarshalling invalid XML content
\n* Ease of use
\n– no need to know xml in order to use
\n* Support customization of
\n– xml -> Java
\n– Java -> xml
\n* Schema derived classes should be
\n– natural\/readable
\n– match conceptual level of source schema<\/p>\n
Non-Goals<\/h3><\/span>\n
* No backward support for J2SE 4.0 or earlier
\n* No DTD support
\n* No support for schema extensions
\n* No support for SOAP encoding
\n* No support for validation on demand by schema derived classes
\n* No support for object graph traversal
\n* No support for mapping any existing Java classes to any existing XML schema<\/p>\n
Reference Implementations (JAXB RI)<\/h2><\/span>\n
* Is an open source project located at https:\/\/jaxb.dev.java.net<\/a>
\n* Included in Java Web Services Developer Pack (JWSDP)<\/p>\n
Download and Install<\/h3><\/span>\n
* Download a desired version from http:\/\/jaxb.java.net<\/a>.
\n* Unpack<\/p>\n
\r\njava -jar JAXB2_.jar\r\n<\/pre>\n
* For example,
\n– Download JAXB 2.2 jar file named JAXB2_20091104.jar<\/a> from http:\/\/jaxb.java.net\/2.2\/<\/a>
\n– Unpack with <\/p>\n
\r\njava -jar JAXB2_20091104.jar\r\n<\/pre>\n
– jaxb-ri-20091104 directory is created.<\/p>\n
Core Classes<\/h3><\/span>\n
* JAXBContext
\n* Marshaller
\n* Unmarshaller<\/p>\n
Compile Schema<\/h3><\/span>\n
* Generates annotated POJOs
\n* Use xjc command line utility<\/p>\n
\r\nC:\\jaxb-ri-20091104\\bin>xjc -help\r\nUsage: xjc [-options ...]  ... [-b ] ...\r\nIf dir is specified, all schema files in it will be compiled.\r\nIf jar is specified, \/META-INF\/sun-jaxb.episode binding file will be compiled.\r\nOptions:\r\n  -nv                :  do not perform strict validation of the input schema(s)\r\n  -extension         :  allow vendor extensions - do not strictly follow the\r\n                        Compatibility Rules and App E.2 from the JAXB Spec\r\n  -b       :  specify external bindings files (each  must have its own -b)\r\n                        If a directory is given, **\/*.xjb is searched\r\n  -d            :  generated files will go into this directory\r\n  -p            :  specifies the target package\r\n  -httpproxy  :  set HTTP\/HTTPS proxy. Format is [user[:password]@]proxyHost:proxyPort\r\n  -httpproxyfile  :  Works like -httpproxy but takes the argument in a file to protect password\r\n  -classpath    :  specify where to find user class files\r\n  -catalog     :  specify catalog files to resolve external entity references\r\n                        support TR9401, XCatalog, and OASIS XML Catalog format.\r\n  -readOnly          :  generated files will be in read-only mode\r\n  -npa               :  suppress generation of package level annotations (**\/package-info.java)\r\n  -no-header         :  suppress generation of a file header with timestamp\r\n  -target 2.0        :  behave like XJC 2.0 and generate code that doesnt use any 2.1 features.\r\n  -xmlschema         :  treat input as W3C XML Schema (default)\r\n  -relaxng           :  treat input as RELAX NG (experimental,unsupported)\r\n  -relaxng-compact   :  treat input as RELAX NG compact syntax (experimental,unsupported)\r\n  -dtd               :  treat input as XML DTD (experimental,unsupported)\r\n  -wsdl              :  treat input as WSDL and compile schemas inside it (experimental,unsupported)\r\n  -verbose           :  be extra verbose\r\n  -quiet             :  suppress compiler output\r\n  -help              :  display this help message\r\n  -version           :  display version information\r\n\r\nExtensions:\r\n  -Xinject-code      :  inject specified Java code fragments into the generated code\r\n  -Xlocator          :  enable source location support for generated code\r\n  -Xsync-methods     :  generate accessor methods with the 'synchronized' keyword\r\n  -mark-generated    :  mark the generated code as @javax.annotation.Generated\r\n  -episode     :  generate the episode file for separate compilation\r\n<\/pre>\n
* Use xjc Ant task (See sample below)<\/p>\n
JAXB Annotations<\/h3><\/span>\n
Class-level Annotations<\/h4><\/span>\n
* XmlRootElement
\n* XmlAccessorType.
\n    PUBLIC_MEMBER \/\/ Default. Marshals all public getter\/setter pairs
\n    FIELD  \/\/ Marshals all nonstatic and nontransient field in the class
\n    PROPERTY \/\/ Like PUBLIC_MEMBER, but also marshals private, protected, or package-only getter\/setter pairs
\n    NONE  \/\/ NO child elements will be marshalled automatically
\n* XmlType
\n* Example<\/p>\n
\r\n@XmlAccessorType(XmlAccessType. FIELD)\r\n@XmlType(name = \"\", propOrder = {\r\n    \"firstName\",\r\n    \"lastName\"\r\n})\r\n@XmlRootElement(name = \"person\")\r\npublic class Person {\r\n}\r\n<\/pre>\n
Filed-level Annotations<\/h4><\/span>\n
* XmlElement
\n    required
\n    nillable
\n    defaultValue
\n* Example<\/p>\n
\r\n@XmlElement(required = true)\r\nprotected String firstName;\r\n@XmlElement(required = true)\r\nprotected String lastName;\r\n<\/pre>\n
Package-level annotations<\/h4><\/span>\n
* Howto
\n– Create a file called package-info.java
\n– Add a regular Java package declaration to it
\n– Add annotations to it
\n* Example<\/p>\n
\r\n@javax. xml. bind. annotation. XmlSchema(\r\n    namespace = \"http: \/\/www. example. com\/person\",\r\n    elementFormDefault = javax. xml. bind. annotation. XmlNsForm. QUALIFIED\r\n)\r\npackage javaxml3;\r\n<\/pre>\n
– declare namespace prefixes:<\/p>\n
\r\n@javax. xml. bind. annotation. XmlSchema(\r\n    namespace = \"http: \/\/www. example. com\/person\",\r\n    elementFormDefault = javax. xml. bind. annotation. XmlNsForm. QUALIFIED,\r\n    xmlns = {\r\n        @javax. xml. bind. annotation. XmlNs(prefix = \"p\",\r\n            namespaceURI=\"http: \/\/www. example. com\/person\")\r\n    }\r\n)\r\npackage javaxml3;\r\n<\/pre>\n
Schema Compilation Customization<\/h3><\/span>\n
* Conceptually similar to annotation
\n* Can be contained in
\n– schema file
\n– external binding file
\n– both
\n* Customization are for elements within the namespace http:\/\/java.sun.com\/xml\/ns\/jaxb<\/p>\n
Inline Declarations<\/h4><\/span>\n
Schema Generation<\/h3><\/span>\n
* Use schemagen command line utility to generate XML schema from annotated Java classes.<\/p>\n
\r\n<\/pre>\n
Marshalling<\/h3><\/span>\n
UnMarshalling<\/h3><\/span>\n
Examples<\/h2><\/span>\n
Books Example<\/h3><\/span>\n
* http:\/\/www.oracle.com\/technetwork\/articles\/javase\/index-140168.html<\/a>
\n* Generate Java with Ant
\n– copy books.xsd to src directory
\n– binding classes are generated in the src directory in package test.jaxb<\/p>\n
\r\n  \r\n  \r\n\r\n\r\n      \r\n          \r\n      <\/fileset>\r\n  <\/path>\r\n\r\n\r\n      \r\n<\/taskdef>\r\n\r\n\r\n  \r\n<\/target>\r\n<\/pre>\n
* Marshalling\/Unmarshalling<\/p>\n
\r\ntry {\r\n  System.out.println(\"Getting JAXBContext...\");\r\n  JAXBContext ctx = JAXBContext.newInstance(\"test.jaxb\");\r\n  System.out.println(\"Got JAXBContext.\");\r\n\r\n  System.out.println(\"Getting Unmarshaller...\");\r\n  Unmarshaller um = ctx.createUnmarshaller();\r\n\r\n  \/\/ Validate against schema\r\n  Schema schema = \r\n    SchemaFactory.newInstance(\r\n      XMLConstants.W3C_XML_SCHEMA_NS_URI).newSchema(\r\n          new File(\"src\" + File.separator + \"books.xsd\"));\r\n  um.setSchema(schema);\r\n  System.out.println(\"Got Unmarshaller.\");\r\n\r\n  System.out.println(\"Getting book colleciton...\");\r\n  Collection bookcol = (Collection)\r\n    um.unmarshal(new File(\"src\" + File.separator + \"books.xml\"));\r\n  System.out.println(\"Got book colleciton.\");\r\n\r\n  List booklist = bookcol.getBooks().getBook();\r\n  for (int i = 0; i < booklist.size(); i++){\r\n    BookType book = booklist.get(i);\r\n    System.out.println(\"Got book: \" + book.getName());\r\n  }\r\n\r\n  \/\/ Marshal back\r\n  System.out.println(\"Getting Marshaller...\");\r\n  Marshaller m = ctx.createMarshaller();\r\n    m.setProperty( Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE );\r\n  System.out.println(\"Got Marshaller.\");\r\n\r\n  System.out.println(\"Marshalling to screen...\");\r\n  m.marshal(bookcol, System.out);\r\n} catch (JAXBException e) {\r\n  \/\/ TODO Auto-generated catch block\r\n  e.printStackTrace();\r\n} catch (SAXException e) {\r\n  \/\/ TODO Auto-generated catch block\r\n  e.printStackTrace();\r\n}\r\n<\/pre>\n
References<\/h2><\/span>\n
* JSR-222 JAXB<\/a>
\n* JAXB 2.0 API<\/a>
\n* java.net jaxb tutorial<\/a>
\n* http:\/\/www.oracle.com\/technetwork\/articles\/javase\/index-140168.html<\/a>
\n* Java and XML, Third Edition By: Brett McLaughlin; Justin Edelson<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview * JAXB = Java Architecture for XML Binding. * Reference implementation is available at http:\/\/jaxb.java.net\/ * JAXB 2.0 is part of – J2EE 5 – JDK 6 * JAXB 2.0 requires – JDK 1.5 JAXB 2.0 vs JAXB 1.0 … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[95],"tags":[],"class_list":["post-2186","post","type-post","status-publish","format-standard","hentry","category-jaxb"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p8cRUO-zg","_links":{"self":[{"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/posts\/2186","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2186"}],"version-history":[{"count":10,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/posts\/2186\/revisions"}],"predecessor-version":[{"id":2281,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/posts\/2186\/revisions\/2281"}],"wp:attachment":[{"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2186"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2186"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2186"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}