Naming space processing and analysis in JBOSS XML Binding framework
Naming space processing and analysis in JBOSS XML Binding framework
introduce
JBOSS XML Binding (JBXB) is a Java framework for processing XML documents.When processing XML documents with naming space, it is very important to understand the basic concepts of naming space and how to parse and process in JBXB.This article will introduce the naming space processing and analysis of the JBOSS XML Binding framework, and provide relevant Java code examples.
What is the name space?
In XML, the name space provides the unique identifier for XML elements and attributes.Naming space is a mechanism that avoids the conflict of elements and attribute names. It is defined by adding prefixes in front of the element and attribute name.For example, assuming that there are two elements names "Book", but they are located in different name spaces.By adding naming space prefixes in front of the element name (such as "NS1: Book" and "NS2: BOOK"), they can ensure that they do not conflict with each other.
How to deal with naming space in JBXB?
The JBoss XML Binding framework can use the annotations such as `@xmlrootElement`,@@@@xmltype` and other annotations to handle naming space.The usage of each annotation will be introduced below.
1. `@xmlrootelement` Note
`@XmlrootElement` Note for marking the root element of the Java class as the XML document, and can specify the attributes related to the namespace.For example, the following code sample marked the Java class `Book` as the root element of the XML document, and set the naming space to` http://www.example.com/books "`.
@XmlRootElement(namespace = "http://www.example.com/books")
public class Book {
// ...
}
2. `@xmlelement` annotation
`@Xmlelement` Annotations are used to mark the mapping relationship between the attributes or fields of the Java class and the XML element, and can specify the attributes related to the name of the element and the name space.For example, the following code example maps the attributes in the Java class `title` to the XML element` <NS1: Title> `, where the name space is` http://www.example.com/books ".
@XmlRootElement(namespace = "http://www.example.com/books")
public class Book {
@XmlElement(namespace = "http://www.example.com/books")
private String title;
// ...
}
3. `@xmltype` Note
`@Xmltype` Annotation is used to specify the types and sequences of the attributes or fields of the Java class, and can specify the attributes related to the naming space.For example, the following code example sets the attribute order in the Java class `Book` to` Title`, `Author`, where the name space is the same as the previous example.
@XmlRootElement(namespace = "http://www.example.com/books")
@XmlType(namespace = "http://www.example.com/books")
public class Book {
@XmlElement(namespace = "http://www.example.com/books")
private String title;
@XmlElement(namespace = "http://www.example.com/books")
private String author;
// ...
}
Analysis of naming space
When using the JBXB framework to analyze the XML document with the naming space, you need to create a `jbxbcontext` object first, and use the object to create an` unmarshaller` object.Then, you can use the `UNMARSHAL` method of the` Unmarshaller` object to convert the XML document into a Java object.Below is an example code that analyzes the XML document with a naming space.
String xml = "<ns1:book xmlns:ns1=\"http://www.example.com/books\"><ns1:title>Java编程</ns1:title></ns1:book>";
try {
JAXBContext jaxbContext = JAXBContext.newInstance(Book.class);
Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
StringReader reader = new StringReader(xml);
Book book = (Book) unmarshaller.unmarshal(reader);
System.out.println (book.gettitle ()); // Output: java programming
} catch (JAXBException e) {
e.printStackTrace();
}
In the above example, we first created an object of `jaxbcontext` and loaded the` Book` class.Then, a `unmarshaller` object was created, and the XML document was converted to the Java object with the` unmarshal` method of the object.Finally, we can obtain data in XML by accessing the corresponding attributes of the Java object.
in conclusion
The JBOSS XML Binding framework provides the function of processing the naming space, making it more convenient to process the XML document with the naming space.By using the annotations of ``@r@@@xmlelement`, and `@xmltype`, it can easily specify the attributes related to the naming space.At the same time, by using the `jaxbcontext` and` unmarshaller` objects, you can easily analyze the XML document with the name space and convert it to the Java object.
I hope this article will help you understand the naming space processing and analysis in the JBoss XML Binding framework.If necessary, you can practice and learn further according to the code provided examples.
