JAXB : Java object to XML without XML Schema

在 jdk 6.0 上面 已經內建 JAXB. 所以直接使用就可以.
研究了一陣子, 看了很多文件. 都大概需要使用xml schema 來產生 java to xml.
不過今天看到一個文章 Generate an XML Document from an Object Model with JAXB 2裡頭有範例, 可以不用使用 XML schema. 就來試試看摟.

開發兩個 Enity Bean(Person.java, Address.java) , 還有一個測試轉換的 Test Code(PersonTest.java).
1. 在 Person 中, 會包涵 Address. 所以在 Person 定義 @XmlRootElement. 這樣Address 也會自動被轉成xml.
2. Address 作一個設定, 原本應該要產生 zipcode tag, 如果想要換成別的. 必須先定義@XmlAccessorType(XmlAccessType.FIELD), 然後在 zipcode field在定義@XmlElement(name = "zip") 這樣轉換出來的address tag 會包涵zip tag 不會是 zipcode tag.




Person.java

package jaxbtest;

import javax.xml.bind.annotation.XmlRootElement;

/**
*
* @author longtai
*/
@XmlRootElement
public class Person {
private String name;
private String email;
private Address address;

/**
* @return the name
*/
public String getName() {
return name;
}

/**
* @param name the name to set
*/
public void setName(String name) {
this.name = name;
}

/**
* @return the email
*/
public String getEmail() {
return email;
}

/**
* @param email the email to set
*/
public void setEmail(String email) {
this.email = email;
}

/**
* @return the address
*/
public Address getAddress() {
return address;
}

/**
* @param address the address to set
*/
public void setAddress(Address address) {
this.address = address;
}

}


Address.java

package jaxbtest;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;

/**
*
* @author longtai
*/
@XmlAccessorType(XmlAccessType.FIELD)
public class Address {
private String address;
@XmlElement(name = "zip")
private String zipcode;

/**
* @return the address
*/
public String getAddress() {
return address;
}

/**
* @param address the address to set
*/
public void setAddress(String address) {
this.address = address;
}

/**
* @return the zipcode
*/
public String getZipcode() {
return zipcode;
}

/**
* @param zipcode the zipcode to set
*/
public void setZipcode(String zipcode) {
this.zipcode = zipcode;
}
}


PersonTest.java

package jaxbtest;

import java.io.StringReader;
import java.io.StringWriter;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import junit.framework.JUnit4TestAdapter;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

/**
*
* @author longtai
*/
public class PersonTest {

public PersonTest() {
}

public static junit.framework.Test suite() {
return new JUnit4TestAdapter(PersonTest.class);
}

@BeforeClass
public static void setUpClass() throws Exception {
}

@AfterClass
public static void tearDownClass() throws Exception {
}

@Test
public void testMarshal() throws Exception {
Person p = new Person();
p.setName("longtai");
p.setEmail("longtai.tw@gmail.com");
Address a = new Address();
a.setAddress("台灣新竹");
a.setZipcode("35002");
p.setAddress(a);

StringWriter writer = new StringWriter();
JAXBContext context = JAXBContext.newInstance(Person.class);
Marshaller m = context.createMarshaller();
m.marshal(p, writer);

System.out.println(writer);
}

@Test
public void testUnmarshal() throws Exception
{
StringReader reader = new StringReader("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?><person><address><address>%u53F0%u7063%u65B0%u7AF9</address><zip>35002</zip></address><email>longtai.tw@gmail.com</email><name>longtai</name></person>");
JAXBContext context = JAXBContext.newInstance(Person.class);
Unmarshaller um = context.createUnmarshaller();
Person p = (Person)um.unmarshal(reader);

System.out.println(p.getName());
System.out.println(p.getAddress().getAddress());
System.out.println(p.getAddress().getZipcode());


}
}