JAXB目前已经集成到了JDK6中，但是还是推荐下载使用最新版的jaxb库， https://jaxb.dev.java.net/
从JAXB2.0开始，可以通过使用annotation进行Object-XMl mapping。
本文将通过以下步骤演示如何使用JAXB annotation绑定使用了namespace的XML文件
1. 创建employees.xml文件
2. 创建Employees.java和Employee.java绑定employees.xml
3. 创建package-info.java和jaxb.index文件
4. 创建XMLParser.java封装marshal/unmarshal操作
5. 创建Test.java运行测试
现在将逐步展开演示
1. 创建employees.xml文件
现在将逐步展开演示
1. 创建employees.xml文件
Xml代码
1.<?xml version="1.0" encoding="utf-8" ?>
2.<employees xmlns:admin="http://www.company.com/management/employees/admin">
3. <admin:employee>
4. <admin:userId>[email protected]</admin:userId>
5. <admin:password>abc123_</admin:password>
6. <admin:name>John Smith</admin:name>
7. <admin:age>24</admin:age>
8. <admin:gender>Male</admin:gender>
9. </admin:employee>
10. <admin:employee>
11. <admin:userId>[email protected]</admin:userId>
12. <admin:password>123456</admin:password>
13. <admin:name>Christine Chen</admin:name>
14. <admin:age>27</admin:age>
15. <admin:gender>Female</admin:gender>
16. </admin:employee>
17.</employees>
<?xml version="1.0" encoding="utf-8" ?>
<employees xmlns:admin="http://www.company.com/management/employees/admin">
<admin:employee>
<admin:userId>[email protected]</admin:userId>
<admin:password>abc123_</admin:password>
<admin:name>John Smith</admin:name>
<admin:age>24</admin:age>
<admin:gender>Male</admin:gender>
</admin:employee>
<admin:employee>
<admin:userId>[email protected]</admin:userId>
<admin:password>123456</admin:password>
<admin:name>Christine Chen</admin:name>
<admin:age>27</admin:age>
<admin:gender>Female</admin:gender>
</admin:employee>
</employees> 这是一个很普通的xml文件，用于展示组织内部的成员（employee）状况，这里有一点需要注意的是使用了namespace，这也是本文将要演示的重点。
2.
创建Employees.java和Employee.java绑定employees.xml
Java代码
1.package com.javaeye.terrencexu.jaxb;
2.
3.import java.util.ArrayList;
4.import java.util.List;
5.
6.import javax.xml.bind.annotation.XmlElement;
7.import javax.xml.bind.annotation.XmlRootElement;
8.
9.@XmlRootElement(name = "employees")
10.public class Employees {
11.
12. @XmlElement(name = "employee", namespace=NameSpace.ADMIN_URI)
13. private List<Employee> employees;
14.
15. public Employees() {
16. employees = new ArrayList<Employee>();
17. }
18.
19. public List<Employee> getEmployees() {
20. return employees;
21. }
22.
23. public void addEmployee(Employee employee) {
24. employees.add(employee);
25. }
26.
27.}
package com.javaeye.terrencexu.jaxb;
import java.util.ArrayList;
import java.util.List;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement(name = "employees")
public class Employees {
@XmlElement(name = "employee", namespace=NameSpace.ADMIN_URI)
private List<Employee> employees;
public Employees() {
employees = new ArrayList<Employee>();
}
public List<Employee> getEmployees() {
return employees;
}
public void addEmployee(Employee employee) {
employees.add(employee);
}
}
Java代码
1.package com.javaeye.terrencexu.jaxb;
2.
3.import javax.xml.bind.annotation.XmlElement;
4.
5.public class Employee {
6.
7. @XmlElement(name = "userId", namespace=NameSpace.ADMIN_URI)
8. private String userId;
9.
10. @XmlElement(name = "password", namespace=NameSpace.ADMIN_URI)
11. private String password;
12.
13. @XmlElement(name = "name", namespace=NameSpace.ADMIN_URI)
14. private String name;
15.
16. @XmlElement(name = "age", namespace=NameSpace.ADMIN_URI)
17. private int age;
18.
19. @XmlElement(name = "gender", namespace=NameSpace.ADMIN_URI)
20. private String gender;
21.
22. public Employee() {
23. }
24.
25. public Employee(String userId, String psw, String name, int age, Gender gender) {
26. this.userId = userId;
27. this.password = psw;
28. this.name = name;
29. this.age = age;
30. this.gender = gender.getValue();
31. }
32.
33. public String getUserId() {
34. return userId;
35. }
36.
37. public String getPassword() {
38. return password;
39. }
40.
41. public String getName() {
42. return name;
43. }
44.
45. public int getAge() {
46. return age;
47. }
48.
49. public String getGender() {
50. return gender;
51. }
52.
53.}
package com.javaeye.terrencexu.jaxb;
import javax.xml.bind.annotation.XmlElement;
public class Employee {
@XmlElement(name = "userId", namespace=NameSpace.ADMIN_URI)
private String userId;
@XmlElement(name = "password", namespace=NameSpace.ADMIN_URI)
private String password;
@XmlElement(name = "name", namespace=NameSpace.ADMIN_URI)
private String name;
@XmlElement(name = "age", namespace=NameSpace.ADMIN_URI)
private int age;
@XmlElement(name = "gender", namespace=NameSpace.ADMIN_URI)
private String gender;
public Employee() {
}
public Employee(String userId, String psw, String name, int age, Gender gender) {
this.userId = userId;
this.password = psw;
this.name = name;
this.age = age;
this.gender = gender.getValue();
}
public String getUserId() {
return userId;
}
public String getPassword() {
return password;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
public String getGender() {
return gender;
}
}
Java代码
1.package com.javaeye.terrencexu.jaxb;
2.
3.public class NameSpace {
4.
5. public static final String ADMIN_PREFIX = "admin";
6. public static final String ADMIN_URI = "http://www.company.com/management/employees/admin";
7.
8.}
package com.javaeye.terrencexu.jaxb;
public class NameSpace {
public static final String ADMIN_PREFIX = "admin";
public static final String ADMIN_URI = "http://www.company.com/management/employees/admin";
}
Java代码
1.package com.javaeye.terrencexu.jaxb;
2.
3.public enum Gender {
4.
5. MALE("Male"),
6. FEMALE("Female");
7.
8. private String value;
9.
10. private Gender(String value) {
11. this.value = value;
12. }
13.
14. public String getValue() {
15. return this.value;
16. }
17.
18.}
package com.javaeye.terrencexu.jaxb;
public enum Gender {
MALE("Male"),
FEMALE("Female");
private String value;
private Gender(String value) {
this.value = value;
}
public String getValue() {
return this.value;
}
}
3. 创建package-info.java和jaxb.index文件
创建package-info.java注册xmlns, 将该文件放在当前source code的package下面，如果不使用namespace可以不创建该文件
Java代码
1.@XmlSchema(
2.xmlns={
3. @XmlNs(prefix=NameSpace.ADMIN_PREFIX, namespaceURI=NameSpace.ADMIN_URI)
4.}
5.)
6.package com.javaeye.terrencexu.jaxb;
7.import javax.xml.bind.annotation.XmlNs;
8.import javax.xml.bind.annotation.XmlSchema;
@XmlSchema(
xmlns={
@XmlNs(prefix=NameSpace.ADMIN_PREFIX, namespaceURI=NameSpace.ADMIN_URI)
}
)
package com.javaeye.terrencexu.jaxb;
import javax.xml.bind.annotation.XmlNs;
import javax.xml.bind.annotation.XmlSchema;
创建jaxb.index注册Employees, Employee，如果不使用包级context，可以不创建该文件
Java代码
1.Employees
2.Employee
Employees
Employee
4. 创建XMLParser.java封装marshal/unmarshal操作
Java代码
1.package com.javaeye.terrencexu.jaxb;
2.
3.import java.io.InputStream;
4.import java.io.StringWriter;
5.
6.import javax.xml.bind.JAXBContext;
7.import javax.xml.bind.JAXBException;
8.import javax.xml.bind.Marshaller;
9.import javax.xml.bind.Unmarshaller;
10.
11.public final class XMLParser {
12.
13. private XMLParser() {}
14.
15. public static Object unmarshal(InputStream xml, Class<?> clazz) {
16. Object obj = null;
17.
18. try {
19. JAXBContext jc = JAXBContext.newInstance(clazz.getPackage().getName());
20. Unmarshaller u = jc.createUnmarshaller();
21. obj = u.unmarshal(xml);
22. } catch (JAXBException e) {
23. throw new RuntimeException("Can't unmarshal the XML file, error message: " + e.getMessage());
24. }
25.
26. return obj;
27. }
28.
29. public static String marshal(Object obj, Class<?> clazz) {
30. String result = null;
31.
32. try {
33. JAXBContext jc = JAXBContext.newInstance(clazz.getPackage().getName());
34. Marshaller m = jc.createMarshaller();
35.
36. StringWriter writer = new StringWriter();
37.
38. m.marshal(obj, writer);
39.
40. result = writer.toString();
41. } catch (JAXBException e) {
42. throw new RuntimeException("Can't marshal the XML file, error message: " + e.getMessage());
43. }
44.
45.
46. return result;
47. }
48.
49.}
package com.javaeye.terrencexu.jaxb;
import java.io.InputStream;
import java.io.StringWriter;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
public final class XMLParser {
private XMLParser() {}
public static Object unmarshal(InputStream xml, Class<?> clazz) {
Object obj = null;
try {
JAXBContext jc = JAXBContext.newInstance(clazz.getPackage().getName());
Unmarshaller u = jc.createUnmarshaller();
obj = u.unmarshal(xml);
} catch (JAXBException e) {
throw new RuntimeException("Can't unmarshal the XML file, error message: " + e.getMessage());
}
return obj;
}
public static String marshal(Object obj, Class<?> clazz) {
String result = null;
try {
JAXBContext jc = JAXBContext.newInstance(clazz.getPackage().getName());
Marshaller m = jc.createMarshaller();
StringWriter writer = new StringWriter();
m.marshal(obj, writer);
result = writer.toString();
} catch (JAXBException e) {
throw new RuntimeException("Can't marshal the XML file, error message: " + e.getMessage());
}
return result;
}
}
5. 创建Test.java运行测试
Java代码
1.package com.javaeye.terrencexu.jaxb;
2.
3.import java.io.File;
4.import java.io.FileInputStream;
5.import java.io.FileNotFoundException;
6.import java.util.List;
7.
8.public class Test {
9.
10. public static void main(String[] args) throws FileNotFoundException {
11. testUnmarshal();
12. testMarshal();
13. }
14.
15. public static void testUnmarshal() throws FileNotFoundException {
16. Employees employees = (Employees) XMLParser.unmarshal(
17. new FileInputStream(new File("F:\\workspace\\JavaStudy\\test\\employees.xml")),
18. Employees.class);
19.
20. List<Employee> employeeList = employees.getEmployees();
21.
22. if (employeeList != null && employeeList.size() > 0) {
23. for (Employee employee : employeeList) {
24. StringBuilder builder = new StringBuilder();
25. builder.append("[UserID: ").append(employee.getUserId()).append(", ")
26. .append("Password: ").append(employee.getPassword()).append(", ")
27. .append("Name: ").append(employee.getName()).append(", ")
28. .append("Age: ").append(employee.getAge()).append(", ")
29. .append("Gender").append(employee.getGender()).append("]");
30.
31. System.out.println(builder.toString());
32. }
33. }
34. }
35.
36. public static void testMarshal() {
37. Employees employees = new Employees();
38. employees.addEmployee(new Employee("[email protected]", "abc123_", "John Smith", 24, Gender.MALE));
39. employees.addEmployee(new Employee("[email protected]", "123456", "Christine Chen", 27, Gender.FEMALE));
40.
41. String result = XMLParser.marshal(employees, Employees.class);
42. System.out.println(result);
43. }
44.}
package com.javaeye.terrencexu.jaxb;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.List;
public class Test {
public static void main(String[] args) throws FileNotFoundException {
testUnmarshal();
testMarshal();
}
public static void testUnmarshal() throws FileNotFoundException {
Employees employees = (Employees) XMLParser.unmarshal(
new FileInputStream(new File("F:\\workspace\\JavaStudy\\test\\employees.xml")),
Employees.class);
List<Employee> employeeList = employees.getEmployees();
if (employeeList != null && employeeList.size() > 0) {
for (Employee employee : employeeList) {
StringBuilder builder = new StringBuilder();
builder.append("[UserID: ").append(employee.getUserId()).append(", ")
.append("Password: ").append(employee.getPassword()).append(", ")
.append("Name: ").append(employee.getName()).append(", ")
.append("Age: ").append(employee.getAge()).append(", ")
.append("Gender").append(employee.getGender()).append("]");
System.out.println(builder.toString());
}
}
}
public static void testMarshal() {
Employees employees = new Employees();
employees.addEmployee(new Employee("[email protected]", "abc123_", "John Smith", 24, Gender.MALE));
employees.addEmployee(new Employee("[email protected]", "123456", "Christine Chen", 27, Gender.FEMALE));
String result = XMLParser.marshal(employees, Employees.class);
System.out.println(result);
}
}
6. 运行结果：
Java代码 1.[UserID: [email protected], Password: abc123_, Name: John Smith, Age: 24, GenderMale] 2.[UserID: [email protected], Password: 123456, Name: Christine Chen, Age: 27, GenderFemale] 3.<?xml version="1.0" encoding="UTF-8" standalone="yes"?><employees xmlns:admin="http://www.company.com/management/employees/admin"><admin:employee><admin:userId>[email protected]</admin:userId><admin:password>abc123_</admin:password><admin:name>John Smith</admin:name><admin:age>24</admin:age><admin:gender>Male</admin:gender></admin:employee><admin:employee><admin:userId>[email protected]</admin:userId><admin:password>123456</admin:password><admin:name>Christine Chen</admin:name><admin:age>27</admin:age><admin:gender>Female</admin:gender></admin:employee></employees>