http://blog.csdn.net/wugouzi/article/details/25044655/
一、简介
JAXB（Java Architecture for XML Binding) 是一个业界的标准，是一项可以根据XML Schema产生Java类的技术。该过程中，JAXB也提供了将XML实例文档反向生成Java对象树的方法，并能将Java对象树的内容重新写到 XML实例文档。
Jaxb 2.0是JDK 1.6的组成部分。我们不需要下载第三方jar包 即可做到轻松转换。Jaxb2使用了JDK的新特性，如：Annotation、GenericType等，需要在即将转换的JavaBean中添加annotation注解。
二、重要概念
•JAXBContext类，是应用的入口，用于管理XML/Java绑定信息。
•Marshaller接口，将Java对象序列化为XML数据。
•Unmarshaller接口，将XML数据反序列化为Java对象。
•@XmlType，将Java类或枚举类型映射到XML模式类型
•@XmlAccessorType(XmlAccessType.FIELD) ，控制字段或属性的序列化。FIELD表示JAXB将自动绑定Java类中的每个非静态的（static）、非瞬态的（由@XmlTransient标 注）字段到XML。其他值还有XmlAccessType.PROPERTY和XmlAccessType.NONE。
•@XmlAccessorOrder，控制JAXB 绑定类中属性和字段的排序。
•@XmlJavaTypeAdapter，使用定制的适配器（即扩展抽象类XmlAdapter并覆盖marshal()和unmarshal()方法），以序列化Java类为XML。
•@XmlElementWrapper ，对于数组或集合（即包含多个元素的成员变量），生成一个包装该数组或集合的XML元素（称为包装器）。
•@XmlRootElement，将Java类或枚举类型映射到XML元素。
•@XmlElement，将Java类的一个属性映射到与属性同名的一个XML元素。
•@XmlAttribute，将Java类的一个属性映射到与属性同名的一个XML属性。
三、示例
1、准备工作
Java代码 收藏代码
1. package utils;
2.
3. import java.io.StringReader;
4. import java.io.StringWriter;
5.
6. import javax.xml.bind.JAXBContext;
7. import javax.xml.bind.Marshaller;
8. import javax.xml.bind.Unmarshaller;
9.
10. /**
11. * Jaxb2工具类
12. * @author zhuc
13. * @create 2013-3-29 下午2:40:14
14. */
15. public class JaxbUtil {
16.
17. /**
18. * JavaBean转换成xml
19. * 默认编码UTF-8
20. * @param obj
21. * @param writer
22. * @return
23. */
24. public static String convertToXml(Object obj) {
25. return convertToXml(obj, "UTF-8");
26. }
27.
28. /**
29. * JavaBean转换成xml
30. * @param obj
31. * @param encoding
32. * @return
33. */
34. public static String convertToXml(Object obj, String encoding) {
35. String result = null;
36. try {
37. JAXBContext context = JAXBContext.newInstance(obj.getClass());
38. Marshaller marshaller = context.createMarshaller();
39. marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
40. marshaller.setProperty(Marshaller.JAXB_ENCODING, encoding);
41.
42. StringWriter writer = new StringWriter();
43. marshaller.marshal(obj, writer);
44. result = writer.toString();
45. } catch (Exception e) {
46. e.printStackTrace();
47. }
48.
49. return result;
50. }
51.
52. /**
53. * xml转换成JavaBean
54. * @param xml
55. * @param c
56. * @return
57. */
58. @SuppressWarnings("unchecked")
59. public static <T> T converyToJavaBean(String xml, Class<T> c) {
60. T t = null;
61. try {
62. JAXBContext context = JAXBContext.newInstance(c);
63. Unmarshaller unmarshaller = context.createUnmarshaller();
64. t = (T) unmarshaller.unmarshal(new StringReader(xml));
65. } catch (Exception e) {
66. e.printStackTrace();
67. }
68.
69. return t;
70. }
71. }
非常简单易懂，需要注意的是
Java代码 收藏代码
1. marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
2. marshaller.setProperty(Marshaller.JAXB_ENCODING, encoding);
Marshaller.JAXB_FORMATTED_OUTPUT 决定是否在转换成xml时同时进行格式化（即按标签自动换行，否则即是一行的xml）
Marshaller.JAXB_ENCODING xml的编码方式
另外，Marshaller 还有其他Property可以设置，可以去查阅api。
2、最简单转换
Java代码 收藏代码
1. package t1;
2.
3. import java.util.Date;
4.
5. import javax.xml.bind.annotation.XmlAccessType;
6. import javax.xml.bind.annotation.XmlAccessorType;
7. import javax.xml.bind.annotation.XmlAttribute;
8. import javax.xml.bind.annotation.XmlElement;
9. import javax.xml.bind.annotation.XmlRootElement;
10. import javax.xml.bind.annotation.XmlType;
11.
12. /**
13. * @author zhuc
14. * @create 2013-3-29 下午2:49:48
15. */
16. @XmlAccessorType(XmlAccessType.FIELD)
17. @XmlRootElement
18. @XmlType(name = "book", propOrder = { "author", "calendar", "price", "id" })
19. public class Book {
20.
21. @XmlElement(required = true)
22. private String author;
23.
24. @XmlElement(name = "price_1", required = true)
25. private float price;
26.
27. @XmlElement
28. private Date calendar;
29.
30. @XmlAttribute
31. private Integer id;
32.
33. /**
34. * @return the author
35. */
36. public String getAuthor() {
37. return author;
38. }
39.
40. /**
41. * @return the price
42. */
43. public float getPrice() {
44. return price;
45. }
46.
47. /**
48. * @return the calendar
49. */
50. public Date getCalendar() {
51. return calendar;
52. }
53.
54. /**
55. * @return the id
56. */
57. public Integer getId() {
58. return id;
59. }
60.
61. /**
62. * @param author the author to set
63. */
64. public void setAuthor(String author) {
65. this.author = author;
66. }
67.
68. /**
69. * @param price the price to set
70. */
71. public void setPrice(float price) {
72. this.price = price;
73. }
74.
75. /**
76. * @param calendar the calendar to set
77. */
78. public void setCalendar(Date calendar) {
79. this.calendar = calendar;
80. }
81.
82. /**
83. * @param id the id to set
84. */
85. public void setId(Integer id) {
86. this.id = id;
87. }
88.
89. /* (non-Javadoc)
90. * @see java.lang.Object#toString()
91. */
92. @Override
93. public String toString() {
94. return "Book [author=" + author + ", price=" + price + ", calendar=" + calendar + ", id=" + id + "]";
95. }
96.
97. }
Java代码 收藏代码
1. package t1;
2.
3. import java.util.Date;
4.
5. import javax.xml.bind.JAXBException;
6.
7. import org.junit.Test;
8.
9. import utils.JaxbUtil;
10.
11. /**
12. * @author zhuc
13. * @create 2013-3-29 下午2:50:00
14. */
15. public class JaxbTest1 {
16.
17. /**
18. * @throws JAXBException
19. */
20. @Test
21. public void showMarshaller() {
22. Book book = new Book();
23. book.setId(100);
24. book.setAuthor("James");
25. book.setCalendar(new Date());
26. book.setPrice(23.45f); //默认是0.0
27.
28. String str = JaxbUtil.convertToXml(book);
29. System.out.println(str);
30. }
31.
32. /**
33. * @throws JAXBException
34. */
35. @Test
36. public void showUnMarshaller() {
37. String str = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>" +
38. "<book id=\"100\">" +
39. " <author>James</author>" +
40. " <calendar>2013-03-29T09:25:56.004+08:00</calendar>" +
41. " <price_1>23.45</price_1>" +
42. "</book>";
43.
44. Book book = JaxbUtil.converyToJavaBean(str, Book.class);
45. System.out.println(book);
46. }
47. }
输出结果分别为：
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<book id="100">
<author>James</author>
<calendar>2013-03-29T14:50:58.974+08:00</calendar>
<price_1>23.45</price_1>
</book>
Book [author=James, price=23.45, calendar=Fri Mar 29 09:25:56 CST 2013, id=100]
3、类中包含复杂对象的转换
Java代码 收藏代码
1. package t2;
2.
3. import javax.xml.bind.annotation.XmlAccessType;
4. import javax.xml.bind.annotation.XmlAccessorType;
5. import javax.xml.bind.annotation.XmlAttribute;
6. import javax.xml.bind.annotation.XmlElement;
7. import javax.xml.bind.annotation.XmlRootElement;
8. import javax.xml.bind.annotation.XmlType;
9.
10. /**
11. * @author zhuc
12. * @create 2013-3-29 下午2:51:44
13. */
14. @XmlAccessorType(XmlAccessType.FIELD)
15. @XmlRootElement(name = "student")
16. @XmlType(propOrder = {})
17. public class Student {
18.
19. @XmlAttribute
20. private Integer id;
21.
22. @XmlElement
23. private String name;
24.
25. @XmlElement(name = "role")
26. private Role role;
27.
28. /**
29. * @return the id
30. */
31. public Integer getId() {
32. return id;
33. }
34.
35. /**
36. * @return the name
37. */
38. public String getName() {
39. return name;
40. }
41.
42. /**
43. * @return the role
44. */
45. public Role getRole() {
46. return role;
47. }
48.
49. /**
50. * @param id the id to set
51. */
52. public void setId(Integer id) {
53. this.id = id;
54. }
55.
56. /**
57. * @param name the name to set
58. */
59. public void setName(String name) {
60. this.name = name;
61. }
62.
63. /**
64. * @param role the role to set
65. */
66. public void setRole(Role role) {
67. this.role = role;
68. }
69.
70. /* (non-Javadoc)
71. * @see java.lang.Object#toString()
72. */
73. @Override
74. public String toString() {
75. return "Student [id=" + id + ", name=" + name + ", role=" + role + "]";
76. }
77.
78. }
Java代码 收藏代码
1. package t2;
2.
3. import javax.xml.bind.annotation.XmlAccessType;
4. import javax.xml.bind.annotation.XmlAccessorType;
5. import javax.xml.bind.annotation.XmlElement;
6. import javax.xml.bind.annotation.XmlType;
7.
8. /**
9. * @author zhuc
10. * @create 2013-3-29 下午2:51:52
11. */
12. @XmlAccessorType(XmlAccessType.FIELD)
13. @XmlType(propOrder = { "name", "desc" })
14. public class Role {
15.
16. @XmlElement
17. private String name;
18.
19. @XmlElement
20. private String desc;
21.
22. /**
23. * @return the name
24. */
25. public String getName() {
26. return name;
27. }
28.
29. /**
30. * @return the desc
31. */
32. public String getDesc() {
33. return desc;
34. }
35.
36. /**
37. * @param name the name to set
38. */
39. public void setName(String name) {
40. this.name = name;
41. }
42.
43. /**
44. * @param desc the desc to set
45. */
46. public void setDesc(String desc) {
47. this.desc = desc;
48. }
49.
50. /* (non-Javadoc)
51. * @see java.lang.Object#toString()
52. */
53. @Override
54. public String toString() {
55. return "Role [name=" + name + ", desc=" + desc + "]";
56. }
57.
58. }
Java代码 收藏代码
1. package t2;
2.
3. import org.junit.Test;
4.
5. import utils.JaxbUtil;
6.
7. /**
8. * @author zhuc
9. * @create 2013-3-29 下午2:52:00
10. */
11. public class JaxbTest2 {
12.
13. @Test
14. public void showMarshaller() {
15.
16. Student student = new Student();
17. student.setId(12);
18. student.setName("test");
19.
20. Role role = new Role();
21. role.setDesc("管理");
22. role.setName("班长");
23.
24. student.setRole(role);
25.
26. String str = JaxbUtil.convertToXml(student);
27. System.out.println(str);
28. }
29.
30. @Test
31. public void showUnMarshaller() {
32. String str = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>"+
33. "<student id=\"12\">"+
34. " <name>test</name>"+
35. " <role>"+
36. " <name>班长</name>"+
37. " <desc>管理</desc>"+
38. "</role>"+
39. "</student>";
40. Student student = JaxbUtil.converyToJavaBean(str, Student.class);
41. System.out.println(student);
42. }
43.
44. }
输出结果分别为：
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<student id="12">
<name>test</name>
<role>
<name>班长</name>
<desc>管理</desc>
</role>
</student>
Student [id=12, name=test, role=Role [name=班长, desc=管理]]
4、集合对象的转换（同样适用于Set）
Java代码 收藏代码
1. package t3;
2.
3. import java.util.List;
4.
5. import javax.xml.bind.annotation.XmlAccessType;
6. import javax.xml.bind.annotation.XmlAccessorType;
7. import javax.xml.bind.annotation.XmlElement;
8. import javax.xml.bind.annotation.XmlElementWrapper;
9. import javax.xml.bind.annotation.XmlRootElement;
10. import javax.xml.bind.annotation.XmlType;
11.
12. /**
13. * @author zhuc
14. * @create 2013-3-29 下午2:55:56
15. */
16. @XmlAccessorType(XmlAccessType.FIELD)
17. @XmlRootElement(name = "country")
18. @XmlType(propOrder = { "name", "provinceList" })
19. public class Country {
20.
21. @XmlElement(name = "country_name")
22. private String name;
23.
24. @XmlElementWrapper(name = "provinces")
25. @XmlElement(name = "province")
26. private List<Province> provinceList;
27.
28. /**
29. * @return the name
30. */
31. public String getName() {
32. return name;
33. }
34.
35. /**
36. * @return the provinceList
37. */
38. public List<Province> getProvinceList() {
39. return provinceList;
40. }
41.
42. /**
43. * @param name the name to set
44. */
45. public void setName(String name) {
46. this.name = name;
47. }
48.
49. /**
50. * @param provinceList the provinceList to set
51. */
52. public void setProvinceList(List<Province> provinceList) {
53. this.provinceList = provinceList;
54. }
55.
56. /* (non-Javadoc)
57. * @see java.lang.Object#toString()
58. */
59. @Override
60. public String toString() {
61. return "Country [name=" + name + ", provinceList=" + provinceList + "]";
62. }
63.
64. }
Java代码 收藏代码
1. package t3;
2.
3. import javax.xml.bind.annotation.XmlAccessType;
4. import javax.xml.bind.annotation.XmlAccessorType;
5. import javax.xml.bind.annotation.XmlElement;
6. import javax.xml.bind.annotation.XmlType;
7.
8. /**
9. * @author zhuc
10. * @create 2013-3-29 下午2:56:03
11. */
12. @XmlAccessorType(XmlAccessType.FIELD)
13. @XmlType(propOrder = { "name", "provCity" })
14. public class Province {
15.
16. @XmlElement(name = "province_name")
17. private String name;
18.
19. @XmlElement(name = "prov_city")
20. private String provCity;
21.
22. /**
23. * @return the provCity
24. */
25. public String getProvCity() {
26. return provCity;
27. }
28.
29. /**
30. * @param provCity the provCity to set
31. */
32. public void setProvCity(String provCity) {
33. this.provCity = provCity;
34. }
35.
36. /**
37. * @return the name
38. */
39. public String getName() {
40. return name;
41. }
42.
43. /**
44. * @param name the name to set
45. */
46. public void setName(String name) {
47. this.name = name;
48. }
49.
50. /* (non-Javadoc)
51. * @see java.lang.Object#toString()
52. */
53. @Override
54. public String toString() {
55. return "Province [name=" + name + ", provCity=" + provCity + "]";
56. }
57.
58. }
Java代码 收藏代码
1. package t3;
2.
3. import java.util.ArrayList;
4. import java.util.List;
5.
6. import org.junit.Test;
7.
8. import utils.JaxbUtil;
9.
10. /**
11. * @author zhuc
12. * @create 2013-3-29 下午2:56:11
13. */
14. public class JaxbTest3 {
15.
16. /**
17. * @throws JAXBException
18. */
19. @Test
20. public void showMarshaller() {
21. Country country = new Country();
22. country.setName("中国");
23.
24. List<Province> list = new ArrayList<Province>();
25. Province province = new Province();
26. province.setName("江苏省");
27. province.setProvCity("南京市");
28. Province province2 = new Province();
29. province2.setName("浙江省");
30. province2.setProvCity("杭州市");
31. list.add(province);
32. list.add(province2);
33.
34. country.setProvinceList(list);
35.
36. String str = JaxbUtil.convertToXml(country);
37. System.out.println(str);
38. }
39.
40. /**
41. *
42. */
43. @Test
44. public void showUnMarshaller() {
45. String str = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>"+
46. "<country>"+
47. " <country_name>中国</country_name>"+
48. " <provinces>"+
49. " <province>"+
50. " <province_name>江苏省</province_name>"+
51. " <prov_city>南京市</prov_city>"+
52. " </province>"+
53. " <province>"+
54. " <province_name>浙江省</province_name>"+
55. " <prov_city>杭州市</prov_city>"+
56. " </province>"+
57. " </provinces>"+
58. "</country>";
59. Country country = JaxbUtil.converyToJavaBean(str, Country.class);
60. System.out.println(country);
61. }
62.
63. }
输出结果分别为：
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<country>
<country_name>中国</country_name>
<provinces>
<province>
<province_name>江苏省</province_name>
<prov_city>南京市</prov_city>
</province>
<province>
<province_name>浙江省</province_name>
<prov_city>杭州市</prov_city>
</province>
</provinces>
</country>
Country [name=中国, provinceList=[Province [name=江苏省, provCity=南京市], Province [name=浙江省, provCity=杭州市]]]
jaxb的使用2 ，包含格式化xml文件
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转载自dannyhz.iteye.com/blog/2317457
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