学步园

先看 xml schema 约束

post.xsd

<?xml version="1.0" encoding="UTF-8"?><br /> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"><br /> <xs:element name="post" type="postType" /><br /> <xs:complexType name="postType"><br /> <xs:sequence maxOccurs="unbounded"><br /> <xs:element name="id" type="xs:long" minOccurs="0"></xs:element><br /> <xs:element name="tiebaName" type="xs:string" minOccurs="0"></xs:element><br /> <xs:element name="url" type="xs:string" minOccurs="0"></xs:element><br /> <xs:element name="title" type="xs:string" minOccurs="0"></xs:element><br /> <xs:element name="author" type="xs:string" minOccurs="0"></xs:element><br /> </xs:sequence><br /> </xs:complexType><br /> </xs:schema>

然后

static String path = PostMarshall.class.getClassLoader().getResource("com/jaxb/tieba/").getPath();<br /> path = URLDecoder.decode(path, "utf-8");</p> <p>JAXBContext factory = JAXBContext.newInstance(Post.class);<br /> Schema schema = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI).newSchema(new File(path,"post.xsd"));<br /> Marshaller ms = factory.createMarshaller();<br /> Post post = new Post();<br /> post.setAuthor("taoge");<br /> //设置schema，验证合法性<br /> ms.setSchema(schema);<br /> ms.marshal(post, new File(path + "post.xml"));<br /> System.out.println(post.getAuthor());

运行java程序

生成的xml如下

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><post><author>taoge</author><id>0</id></post>

创建的 post 对象其 id == 0

所以会出现上述结果