{"id":1158,"date":"2016-10-25T19:12:27","date_gmt":"2016-10-25T19:12:27","guid":{"rendered":"http:\/\/blog.paranoidprofessor.com\/?p=1158"},"modified":"2016-10-25T19:12:27","modified_gmt":"2016-10-25T19:12:27","slug":"fun-with-xml-jaxb-and-arrays","status":"publish","type":"post","link":"https:\/\/blog.paranoidprofessor.com\/index.php\/2016\/10\/25\/fun-with-xml-jaxb-and-arrays\/","title":{"rendered":"fun with XML – JAXB and arrays"},"content":{"rendered":"

In part I of my JAXB example<\/a> I briefly described some of the annotations required to turn normal Java objects into XML files with JAXB.<\/p>\n

To expand on the xml examples from my previous post,\u00a0I will be taking a number of small java objects and load them into an array. What makes this interesting is that the number of XML objects is not known nor all that important when loading or saving.<\/p>\n

\r\n<?xml version="1.0" encoding="UTF-8" standalone="yes"?>\r\n<Library>\r\n    <Publication>\r\n        <Author>Robert Heinlein<\/Author>\r\n        <Title>Have spacesuit will travel<\/Title>\r\n        <Price>15.99<\/Price>\r\n        <Isbn>095524347<\/Isbn>\r\n    <\/Publication>\r\n    \r\n     ...\r\n\r\n    <Publication>\r\n        <Author>Robert Heinlein<\/Author>\r\n        <Title>Stranger in a strange land<\/Title>\r\n        <Price>15.99<\/Price>\r\n        <Isbn>0123123123<\/Isbn>\r\n    <\/Publication>\r\n<\/Library>\r\n<\/pre>\n
Actually, there isn’t really all that much more that needs to be explained. \u00a0The marshal and unmarshal\u00a0methods converts between xml and plain old java objects. \u00a0There is one slight difference.<\/p>\n
The\u00a0top level class is annotated with the @XmlRootElement annotation, then its value is represented as XML element in an XML document. \u00a0The actual subobjects or subelements cannot have this tag.<\/p>\n
The bookcollection is the top class which is just an array of books which in this case is essentially the primitive.<\/p>\n
In my example, the bookcollection is perhaps not a clean separation between the actual xml object and the methods that use it. \u00a0All of the methods that are part of this class are not necessary. \u00a0The only important part of the class is the following lines.<\/p>\n
\r\npackage de.companyname.complex;\r\n\r\nimport javax.xml.bind.annotation.*;\r\nimport org.apache.log4j.Logger;\r\n\r\n@XmlRootElement(name="Library")\r\n@XmlAccessorType(XmlAccessType.FIELD)\r\n\r\npublic class bookcollection {\r\n\r\n\t@XmlElement(name="Publication")\r\n\tprivate book[] cardcatalog;\r\n\r\n\t...\r\n<\/pre>\n
The example is pretty straight forward to understand. \u00a0It loads the xml data and dumps it to the console.<\/p>\n