jdk提供了JAXB来解析bean和xml之间的转换
常用注解
@XmlTransient:不参与序列化(有该注解表示瞬态,没有表示非瞬态)
@XmlAccessorType:控制字段或属性是否序列化
- XmlAccessorType.FIELD:类中的每个非静态、非瞬态字段将自动绑定到XML
- XmlAccessorType.NONE:没有字段或属性绑定到XML,除非使用特定的注解
- XmlAccessorType.PROPERTY:类中的getter / setter对将被自动绑定到XML,除了瞬态的
- XmlAccessorType.PUBLIC_MEMBER:默认的序列化。类中的公共getter / setter对和每个公共字段将被自动绑定到XML,除了瞬态的
@XmlAccessorOrder:控制类中字段和属性的顺序
- XmlAccessOrder.ALPHABETICAL:排序按照String.compareTo方法确定的字母顺序
- XmlAccessOrder.UNDEFINED:默认的排序。按照类中字段的顺序排序
@XmlType:将类或枚举类型映射到XML模式类型
- propOrder:自定义排序
@XmlRootElement:根目录,默认为类名称
@XmlAttribute:将类属性映射到XML属性,默认为字段名称
@XmlElement:将类属性映射到XML元素,默认为字段名称。当序列化为XmlAccessorType.NONE或修改映射名称时使用
@XmlElementRef:映射其他类属性到XML元素
example:
@XmlAccessorType(XmlAccessType.FIELD)
@XmlAccessorOrder(XmlAccessOrder.ALPHABETICAL)
//@XmlType(propOrder = {"name", "id", "sex", "age"})
@XmlRootElement
public class User {
@XmlAttribute
private Long id;
@XmlElement(name = "nickname")
private String name;
private Integer age;
private Boolean sex;
@XmlElementRef
private Account account;
//getter setter toString省略。。。
}
@XmlAccessorType(XmlAccessType.FIELD)
@XmlAccessorOrder(XmlAccessOrder.ALPHABETICAL)
@XmlRootElement
public class Account {
private String username;
private String password;
//getter setter toString省略。。。
}
bean转xml
@Test
public void bean2xml(){
User user = new User();
user.setId(1L);
user.setName("xiaoming");
user.setAge(18);
user.setSex(true);
Account account = new Account();
account.setUsername("admin");
account.setPassword("123456");
user.setAccount(account);
//获取JAXBContext
JAXBContext jaxbContext = JAXBContext.newInstance(User.class);
//创建一个可用于将java内容树转换为XML数据的Marshaller对象
Marshaller marshaller = jaxbContext.createMarshaller();
//指定编组的XML数据是否使用换行符和缩进格式化的属性的名称
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
//将解析的xml封装到StringWriter中
StringWriter writer = new StringWriter();
marshaller.marshal(user, writer);
System.out.println(writer.toString());
}
结果:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<user id="1">
<account>
<password>123456</password>
<username>admin</username>
</account>
<age>18</age>
<nickname>xiaoming</nickname>
<sex>true</sex>
</user>
xml转bean
@Test
public void xml2bean
//bean转换成xml的结果
String xml = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n" +
"<user id=\"1\">\n" +
" <account>\n" +
" <password>123456</password>\n" +
" <username>admin</username>\n" +
" </account>\n" +
" <age>18</age>\n" +
" <nickname>xiaoming</nickname>\n" +
" <sex>true</sex>\n" +
"</user>";
//获取JAXBContext
JAXBContext jaxbContext = JAXBContext.newInstance(User.class);
//创建一个可以将XML数据转换为java内容树的 Unmarshaller对象
Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
//解析StringReader中的xml
StringReader reader = new StringReader(xml);
Object unmarshal = unmarshaller.unmarshal(reader);
System.out.println(unmarshal);
}
结果:
User{id=1, name='xiaoming', age=18, sex=true, account=Account{username='admin', password='123456'}}
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