jaxb实现javabean和xml间互相转换

1.java bean->xml

@Test    public void marshalTest() {        try {            JAXBContext jContext = JAXBContext.newInstance(User.class);            Marshaller marshaller = jContext.createMarshaller();            Pet pet = new Pet("dog","小哈");            Book aBook = new Book("平凡的世界", 20);            Book bBook = new Book("明晓溪",15);            List<Book> books = new ArrayList<Book>();            books.add(aBook);            books.add(bBook);            User user = new User("张三","女", 20, new Date(), null, pet, books);            //设置生成的xml的编码            marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");            //设置生成的xml内容是否format，否的话是显示一行            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);            //是否省略头部声明信息，默认false            marshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);            //直接输出文件            marshaller.marshal(user, new File("a.xml"));                        OutputStream out = new ByteArrayOutputStream();            //输出字节流            marshaller.marshal(user, out);            System.out.println("========"+out.toString());        } catch (JAXBException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }

JDK1.7及之后做了更多封装，更加简单： 

JAXB.marshal(user, new File("b.xml"));

2.xml->javabean

@Test    public void unmarshallTest() {        try {            JAXBContext jaxbContext = JAXBContext.newInstance(User.class);            Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();            User user = (User) unmarshaller.unmarshal(new File("a.xml"));            System.out.println(user.toString());                    } catch (JAXBException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }

1.7及之后：

User user2 = JAXB.unmarshal(new File("b.xml"), User.class);