Figure 17–2 shows what occurs during the JAXB binding process.
The general steps in the JAXB data binding process are:
Generate classes: An XML schema is used as input to the JAXB binding compiler to generate JAXB classes based on that schema.
Compile classes: All of the generated classes, source files, and application code must be compiled.
Unmarshal: XML documents written according to the constraints in the source schema are unmarshalled by the JAXB binding framework. Note that JAXB also supports unmarshalling XML data from sources other than files/documents, such as DOM nodes, string buffers, SAX Sources, and so forth.
Generate content tree: The unmarshalling process generates a content tree of data objects instantiated from the generated JAXB classes; this content tree represents the structure and content of the source XML documents.
Validate (optional): The unmarshalling process optionally involves validation of the source XML documents before generating the content tree. Note that if you modify the content tree in Step 6, below, you can also use the JAXB Validate operation to validate the changes before marshalling the content back to an XML document.
Process content: The client application can modify the XML data represented by the Java content tree by means of interfaces generated by the binding compiler.
Marshal: The processed content tree is marshalled out to one or more XML output documents. The content may be validated before marshalling.