Java Objects and XML transformations

Sometimes we need to convert a Java object into an XML file. This can be achieved using JAXB. (JDK1.6 and later versions do not need to import dependency packages because they are already included in the JDK)

If a company has many departments, and there are many employees in each department, we can design simple bean objects like this.

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2. @XmlRootElement (name="department")
4. Public class Department {
8. private String name; //Department name
10. Private list<staff> staffs; //Actually staff is comprehended, here is plus ' s ' is to distinguish staff
14. Public String GetName () {
16. return name;
18. }
20. @XmlAttribute
22. public void SetName (String name) {
24. this.name = name;
26. }
28. Public list<staff> getstaffs () {
30. return staffs;
32. }
34. @XmlElement (name="Staff")
36. public void Setstaffs (list<staff> staffs) {
38. this.staffs = staffs;
40. }
42. }

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2. @XmlRootElement (name="Staff")
4. Public class Staff {
8. private String name; //Staff name
10. private int age; //Staff age
12. private Boolean smoker; /Is it a smoker ?
16. Public String GetName () {
18. return name;
20. }
22. @XmlElement
24. public void SetName (String name) {
26. this.name = name;
28. }
30. public int getage () {
32. return age;
34. }
36. @XmlElement
38. public void Setage (int.) {
40. this.age = age;
42. }
44. Public Boolean issmoker () {
46. return smoker;
48. }
50. @XmlAttribute
52. public void Setsmoker (boolean smoker) {
54. this.smoker = smoker;
56. }
58. }

The following will generate a simple object and convert it into an XML string.

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2. Public class Main {
6. public static void Main (string[] args) throws Exception {
10. Jaxbcontext context = Jaxbcontext.newinstance (Department. Class,staff.    class); //Get Context object
12. Marshaller Marshaller = Context.createmarshaller (); //Get Marshaller object based on context
16. Marshaller.setproperty (marshaller.jaxb_encoding, "UTF-8"); //Set coded character sets
18. Marshaller.setproperty (Marshaller.jaxb_formatted_output, true); //formatted XML output, with branches and indents
22. Marshaller.marshal (Getsimpledepartment (), System.out); //Print to console
26. Bytearrayoutputstream BAOs = new Bytearrayoutputstream ();
28. Marshaller.marshal (Getsimpledepartment (), BAOs);
30. String xmlobj = new String (Baos.tobytearray ()); //Generate XML string
32. System.out.println (Xmlobj);
34. }
38. /** 
40. * Generate a simple Department object
42. * @return
44. */
46. private static Department getsimpledepartment () {
48. list<staff> staffs = new arraylist<staff> ();
52. Staff STF = new staff ();
54. Stf.setname ("Jay Chou");
56. Stf.setage (30);
58. Stf.setsmoker (false);
60. Staffs.add (STF);
62. Stf.setname ("weekly Pen Chang");
64. Stf.setage (28);
66. Stf.setsmoker (false);
68. Staffs.add (STF);
70. Stf.setname ("Stephen Chow Chi");
72. Stf.setage (40);
74. Stf.setsmoker (true);
76. Staffs.add (STF);
80. Department Dept = New Department ();
82. Dept.setname ("Entertainment Circle");
84. Dept.setstaffs (staffs);
88. return dept;
90. }
92. }

Console printing information:

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2. <?xml version= "1.0" encoding= "UTF-8" standalone= "yes"?>
4. <department name= "Entertainment Circle" >
6. <staff smoker= "true" >
8. <age>40</age>
10. <name> Stephen Chow </name>
12. </staff>
14. <staff smoker= "true" >
16. <age>40</age>
18. <name> Stephen Chow </name>
20. </staff>
22. <staff smoker= "true" >
24. <age>40</age>
26. <name> Stephen Chow </name>
28. </staff>
30. </department>

Notice that we can convert an object to an XML file using the Marshaller.marshal method, or we can convert the XML to an object using Unmarshaller.unmarshal.

Java Objects and XML transformations