jaxb的优点和用法
一、jaxb是什么
JAXB是Java Architecture for XML Binding的缩写。可以将一个Java对象转变成为XML格式，反之亦然。
我们把对象与关系数据库之间的映射称为ORM，其实也可以把对象与XML之间的映射称为OXM(Object XML Mapping)。原来JAXB是Java EE的一部分，在JDK1.6中，SUN将其放到了Java SE中，这也是SUN的一贯做法。JDK1.6中自带的这个JAXB版本是2.0，比起1.0(JSR 31)来，JAXB2(JSR 222)用JDK5的新特性Annotation来标识要作绑定的类和属性等，这就极大简化了开发的工作量。
二、jaxb应用模式
在JAVA EE 5\6中，jaxb可以很方便的与jax-rs、jax-ws集成，极大的简化了web service接口的开发工作量。
三、jaxb代码举例
第一步：需要引入
javax.xml.bind.jar
第二步：编写java bean;
package com.mkyong.core;import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;@XmlRootElement
public class Customer {String name;int age;int id;public String getName() {return name;}@XmlElementpublic void setName(String name) {this.name = name;}public int getAge() {return age;}@XmlElementpublic void setAge(int age) {this.age = age;}public int getId() {return id;}@XmlAttributepublic void setId(int id) {this.id = id;}}第三步：main方法把java bean转化为xml字符串
package com.mkyong.core;import java.io.File;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;public class JAXBExample {public static void main(String[] args) {Customer customer = new Customer();customer.setId(100);customer.setName("mkyong");customer.setAge(29);try {File file = new File("C:\\file.xml");JAXBContext jaxbContext = JAXBContext.newInstance(Customer.class);Marshaller jaxbMarshaller = jaxbContext.createMarshaller();// output pretty printedjaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);jaxbMarshaller.marshal(customer, file);jaxbMarshaller.marshal(customer, System.out);} catch (JAXBException e) {e.printStackTrace();}}
}下面是输出：
29 mkyong
四、jaxb开发常用
jdk提供了xjc工具可以使xsd自动生成相应的java bean，这大大提高了开发的效率。同时，我们也可以使用 trang.jar把xml轻松转化为xsd。下面是使用的举例。
第一步：把数据库表映射为xml
java -jar D:\lib\trang.jar user.xml user.xsd//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vJAXB 2.1.10 in JDK 6
// See http://java.sun.com/xml/jaxb
// Any modifications to this file will be lost upon recompilation of the source schema.
// Generated on: 2011.11.13 at 01:26:07 ���� CST
//package com.moto.server.bean;import java.math.BigInteger;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlSchemaType;
import javax.xml.bind.annotation.XmlType;
import javax.xml.bind.annotation.adapters.CollapsedStringAdapter;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;/*** Java class for anonymous complex type.* *
The following schema fragment specifies the expected content contained within this class.* *
* * * * * * *
* * */
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "")
@XmlRootElement(name = "User")
public class User {@XmlAttribute(name = "u_avatar", required = true)@XmlJavaTypeAdapter(CollapsedStringAdapter.class)@XmlSchemaType(name = "NCName")protected String uAvatar;@XmlAttribute(name = "u_email", required = true)@XmlSchemaType(name = "anySimpleType")protected String uEmail;@XmlAttribute(name = "u_hometown", required = true)@XmlJavaTypeAdapter(CollapsedStringAdapter.class)@XmlSchemaType(name = "NCName")protected String uHometown;@XmlAttribute(name = "u_id", required = true)protected BigInteger uId;@XmlAttribute(name = "u_job", required = true)@XmlJavaTypeAdapter(CollapsedStringAdapter.class)@XmlSchemaType(name = "NCName")protected String uJob;@XmlAttribute(name = "u_mobile", required = true)protected BigInteger uMobile;@XmlAttribute(name = "u_mood", required = true)@XmlJavaTypeAdapter(CollapsedStringAdapter.class)@XmlSchemaType(name = "NCName")protected String uMood;@XmlAttribute(name = "u_name", required = true)@XmlJavaTypeAdapter(CollapsedStringAdapter.class)@XmlSchemaType(name = "NCName")protected String uName;@XmlAttribute(name = "u_state", required = true)@XmlJavaTypeAdapter(CollapsedStringAdapter.class)@XmlSchemaType(name = "NCName")protected String uState;/*** Gets the value of the uAvatar property.* * @return* possible object is* {@link String }* */public String getUAvatar() {return uAvatar;}/*** Sets the value of the uAvatar property.* * @param value* allowed object is* {@link String }* */public void setUAvatar(String value) {this.uAvatar = value;}/*** Gets the value of the uEmail property.* * @return* possible object is* {@link String }* */public String getUEmail() {return uEmail;}/*** Sets the value of the uEmail property.* * @param value* allowed object is* {@link String }* */public void setUEmail(String value) {this.uEmail = value;}/*** Gets the value of the uHometown property.* * @return* possible object is* {@link String }* */public String getUHometown() {return uHometown;}/*** Sets the value of the uHometown property.* * @param value* allowed object is* {@link String }* */public void setUHometown(String value) {this.uHometown = value;}/*** Gets the value of the uId property.* * @return* possible object is* {@link BigInteger }* */public BigInteger getUId() {return uId;}/*** Sets the value of the uId property.* * @param value* allowed object is* {@link BigInteger }* */public void setUId(BigInteger value) {this.uId = value;}/*** Gets the value of the uJob property.* * @return* possible object is* {@link String }* */public String getUJob() {return uJob;}/*** Sets the value of the uJob property.* * @param value* allowed object is* {@link String }* */public void setUJob(String value) {this.uJob = value;}/*** Gets the value of the uMobile property.* * @return* possible object is* {@link BigInteger }* */public BigInteger getUMobile() {return uMobile;}/*** Sets the value of the uMobile property.* * @param value* allowed object is* {@link BigInteger }* */public void setUMobile(BigInteger value) {this.uMobile = value;}/*** Gets the value of the uMood property.* * @return* possible object is* {@link String }* */public String getUMood() {return uMood;}/*** Sets the value of the uMood property.* * @param value* allowed object is* {@link String }* */public void setUMood(String value) {this.uMood = value;}/*** Gets the value of the uName property.* * @return* possible object is* {@link String }* */public String getUName() {return uName;}/*** Sets the value of the uName property.* * @param value* allowed object is* {@link String }* */public void setUName(String value) {this.uName = value;}/*** Gets the value of the uState property.* * @return* possible object is* {@link String }* */public String getUState() {return uState;}/*** Sets the value of the uState property.* * @param value* allowed object is* {@link String }* */public void setUState(String value) {this.uState = value;}}本文来自互联网用户投稿，文章观点仅代表作者本人，不代表本站立场，不承担相关法律责任。如若转载，请注明出处。 如若内容造成侵权/违法违规/事实不符，请点击【内容举报】进行投诉反馈！