Java解析和生成XML

2022-12-07 10:48:44

1、Jaxb处理java对象和xml之间转换常用的annotation有：
  1. @XmlType
  1. @XmlElement
  1. @XmlRootElement
  1. @XmlAttribute
  1. @XmlAccessorType
  1. @XmlAccessorOrder
  1. @XmlTransient
  1. @XmlJavaTypeAdapter
2、常用annotation使用说明
@XmlType
　　@XmlType用在class类的注解，常与@XmlRootElement，@XmlAccessorType一起使用。它有三个属性：name、propOrder、namespace，经常使用的只有前两个属性。如：
　　 
@XmlType(name = "basicStruct", propOrder = {

    "intValue",

    "stringArray",

    "stringValue")
在使用@XmlType的propOrder 属性时，必须列出JavaBean对象中的所有属性，否则会报错。
  • @XmlElement
@XmlElement将Java对象的属性映射为xml的节点，在使用@XmlElement时，可通过name属性改变java对象属性在xml中显示的名称。如：
　　@XmlElement(name="Address")　　
　　private String yourAddress;
 
@XmlRootElement
  • @XmlRootElement用于类级别的注解，对应xml的跟元素，常与 @XmlType 和 @XmlAccessorType一起使用。如：
　　@XmlType
　　@XmlAccessorType(XmlAccessType.FIELD)
　　@XmlRootElement
　　public class Address {}
 
@XmlAttribute
@XmlAttribute用于把java对象的属性映射为xml的属性,并可通过name属性为生成的xml属性指定别名。如：
　　@XmlAttribute(name="Country")
　　private String state;
 
@XmlAccessorType
@XmlAccessorType用于指定由java对象生成xml文件时对java对象属性的访问方式。常与@XmlRootElement、@XmlType一起使用。它的属性值是XmlAccessType的4个枚举值，分　别为：
　　XmlAccessType.FIELD:java对象中的所有成员变量
　　XmlAccessType.PROPERTY：java对象中所有通过getter/setter方式访问的成员变量
　　XmlAccessType.PUBLIC_MEMBER：java对象中所有的public访问权限的成员变量和通过getter/setter方式访问的成员变量
　　XmlAccessType.NONE:java对象的所有属性都不映射为xml的元素
　　注意：@XmlAccessorType的默认访问级别是XmlAccessType.PUBLIC_MEMBER，因此，如果java对象中的private成员变量设置了public权限的getter/setter方法，就不要在　　　private变量上使用@XmlElement和@XmlAttribute注解，否则在由java对象生成xml时会报同一个属性在java类里存在两次的错误。同理，如果@XmlAccessorType的访问权限　　　为XmlAccessType.NONE，如果在java的成员变量上使用了@XmlElement或@XmlAttribute注解，这些成员变量依然可以映射到xml文件。
 
@XmlAccessorOrder
@XmlAccessorOrder用于对java对象生成的xml元素进行排序。它有两个属性值：
　　AccessorOrder.ALPHABETICAL：对生成的xml元素按字母书序排序
　　XmlAccessOrder.UNDEFINED:不排序
 
@XmlTransient
@XmlTransient用于标示在由java对象映射xml时，忽略此属性。即，在生成的xml文件中不出现此元素。
 
@XmlJavaTypeAdapter
@XmlJavaTypeAdapter常用在转换比较复杂的对象时，如map类型或者格式化日期等。使用此注解时，需要自己写一个adapter类继承XmlAdapter抽象类，并实现里面的方法。
　　@XmlJavaTypeAdapter(value=xxx.class),value为自己定义的adapter类
　　XmlAdapter如下：
public abstract class XmlAdapter<ValueType,BoundType> {

    // Do-nothing constructor for the derived classes.

    protected XmlAdapter() {}

    // Convert a value type to a bound type.

    public abstract BoundType unmarshal(ValueType v);

    // Convert a bound type to a value type.

    public abstract ValueType marshal(BoundType v);

 }
3、示例
Shop.java
import java.io.FileReader;

import java.io.FileWriter;

import java.math.BigDecimal;

import java.util.Date;

import java.util.HashSet;

import java.util.Set;

import javax.xml.bind.JAXBContext;

import javax.xml.bind.Marshaller;

import javax.xml.bind.Unmarshaller;

import javax.xml.bind.annotation.XmlAccessType;

import javax.xml.bind.annotation.XmlAccessorOrder;

import javax.xml.bind.annotation.XmlAccessOrder;

import javax.xml.bind.annotation.XmlAccessorType;

import javax.xml.bind.annotation.XmlAttribute;

import javax.xml.bind.annotation.XmlElement;

import javax.xml.bind.annotation.XmlElementWrapper;

import javax.xml.bind.annotation.XmlRootElement;

import javax.xml.bind.annotation.XmlType;

//设置生成的xml的根节点的名称

@XmlRootElement(name = "shop")

//设置根据字段还是方法生成

@XmlAccessorType(XmlAccessType.FIELD)

@XmlAccessorOrder(XmlAccessOrder.ALPHABETICAL)

@XmlType(name = "shop", propOrder = { "name", "number", "describer", "address","orders" })

public class Shop {

    public static void main(String[] args) {

        Set<Order> orders = new HashSet<Order>();  

        Address address1 = new Address("China", "ShangHai", "ShangHai", "Huang", "200000");

        Customer customer1 = new Customer("Jim", "male", "13699990000", address1);

        Order order1 = new Order("Mart", "LH59900", new Date(), new BigDecimal(60), 1);

        order1.setCustomer(customer1);

        Address address2 = new Address("China", "JiangSu", "NanJing", "ZhongYangLu", "210000");

        Customer customer2 = new Customer("David", "male", "13699991000", address2);

        Order order2 = new Order("Mart", "LH59800", new Date(), new BigDecimal(80), 1);

        order2.setCustomer(customer2);  

        orders.add(order1);

        orders.add(order2);  

        Address address3 = new Address("China", "ZheJiang", "HangZhou", "XiHuRoad", "310000");

        Shop shop = new Shop("CHMart", "100000", "EveryThing",address3);

        shop.setOrders(orders);  

        FileWriter writer = null;

        try {

            JAXBContext context = JAXBContext.newInstance(Shop.class);

            Marshaller marshal = context.createMarshaller();

            marshal.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

            marshal.marshal(shop, System.out);  

            writer = new FileWriter("shop.xml");

            marshal.marshal(shop, writer); 

            Unmarshaller unmarshal = context.createUnmarshaller();

            FileReader reader = new FileReader("shop.xml") ;

            Shop shop1 = (Shop)unmarshal.unmarshal(reader);  

            Set<Order> orders1 = shop1.getOrders();

            for(Order order : orders1){

                System.out.println("***************************");

                System.out.println(order.getOrderNumber());

                System.out.println(order.getCustomer().getName());

                System.out.println("***************************");

            }

        } catch (Exception e) {

            e.printStackTrace();

        }  

    }

    @XmlAttribute

    private String name;  

    // @XmlElement

    private String number;  

    @XmlElement

    private String describer;  

    @XmlElementWrapper(name = "orders")

    @XmlElement(name = "order")

    private Set<Order> orders;  

    @XmlElement

    private Address address;  

    public Shop() {

    }  

    public Shop(String name, String number, String describer, Address address) {

        this.name = name;

        this.number = number;

        this.describer = describer;

        this.address = address;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getNumber() {

        return number;

    }

    public void setNumber(String number) {

        this.number = number;

    }

    public String getDescriber() {

        return describer;

    }

    public void setDescriber(String describer) {

        this.describer = describer;

    }

    public Set<Order> getOrders() {

        return orders;

    }

    public void setOrders(Set<Order> orders) {

        this.orders = orders;

    }

    public Address getAddress() {

        return address;

    }

    public void setAddress(Address address) {

        this.address = address;

    }

}

Order.java

import java.math.BigDecimal;

import java.util.Date;

import javax.xml.bind.annotation.XmlAccessorType;

import javax.xml.bind.annotation.XmlAccessType;

import javax.xml.bind.annotation.XmlAttribute;

import javax.xml.bind.annotation.XmlRootElement;

import javax.xml.bind.annotation.XmlType;

import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;

@XmlType(name="order",propOrder={"shopName","orderNumber","price","amount","purDate","customer"})

@XmlAccessorType(XmlAccessType.FIELD)

@XmlRootElement

public class Order {

    private String shopName;  

    @XmlAttribute

    private String orderNumber;  

    @XmlJavaTypeAdapter(value=DateAdapter.class)

    private Date purDate;  

    private BigDecimal price;  

    private int amount;  

    private Customer customer;  

    public Order() {

    }  

    public Order(String shopName, String orderNumber, Date purDate,

            BigDecimal price, int amount) {

        this.shopName = shopName;

        this.orderNumber = orderNumber;

        this.purDate = purDate;

        this.price = price;

        this.amount = amount;

    }

    public String getShopName() {

        return shopName;

    }

    public void setShopName(String shopName) {

        this.shopName = shopName;

    }

    public String getOrderNumber() {

        return orderNumber;

    }

    public void setOrderNumber(String orderNumber) {

        this.orderNumber = orderNumber;

    }

    public Date getPurDate() {

        return purDate;

    }

    public void setPurDate(Date purDate) {

        this.purDate = purDate;

    }

    public BigDecimal getPrice() {

        return price;

    }

    public void setPrice(BigDecimal price) {

        this.price = price;

    }

    public int getAmount() {

        return amount;

    }

    public void setAmount(int amount) {

        this.amount = amount;

    }

    public Customer getCustomer() {

        return customer;

    }

    public void setCustomer(Customer customer) {

        this.customer = customer;

    }  

}

Customer.java

import java.util.Set;

import javax.xml.bind.annotation.XmlAccessorType;

import javax.xml.bind.annotation.XmlAccessType;

import javax.xml.bind.annotation.XmlAttribute;

import javax.xml.bind.annotation.XmlRootElement;

import javax.xml.bind.annotation.XmlType;

@XmlType

@XmlAccessorType(XmlAccessType.FIELD)

@XmlRootElement

public class Customer {

    @XmlAttribute

    private String name;  

    private String gender;  

    private String phoneNo;  

    private Address address;  

    private Set<Order> orders;  

    public Customer() {

    }  

    public Customer(String name, String gender, String phoneNo, Address address) {

        this.name = name;

        this.gender = gender;

        this.phoneNo = phoneNo;

        this.address = address;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getGender() {

        return gender;

    }

    public void setGender(String gender) {

        this.gender = gender;

    }

    public String getPhoneNo() {

        return phoneNo;

    }

    public void setPhoneNo(String phoneNo) {

        this.phoneNo = phoneNo;

    }

    public Address getAddress() {

        return address;

    }

    public void setAddress(Address address) {

        this.address = address;

    }

    public Set<Order> getOrders() {

        return orders;

    }

    public void setOrders(Set<Order> orders) {

        this.orders = orders;

    }  

}

Address.java

import javax.xml.bind.annotation.XmlAccessorOrder;

import javax.xml.bind.annotation.XmlAccessOrder;

import javax.xml.bind.annotation.XmlAccessorType;

import javax.xml.bind.annotation.XmlAccessType;

import javax.xml.bind.annotation.XmlAttribute;

import javax.xml.bind.annotation.XmlElement;

import javax.xml.bind.annotation.XmlRootElement;

import javax.xml.bind.annotation.XmlType;

@XmlType(propOrder = { "state", "province", "city", "street", "zip" })

@XmlAccessorOrder(XmlAccessOrder.ALPHABETICAL)

@XmlAccessorType(XmlAccessType.NONE)

@XmlRootElement

public class Address {

    @XmlAttribute

    private String state;

    @XmlElement

    private String province;

    @XmlElement

    private String city;

    @XmlElement

    private String street;

    @XmlElement

    private String zip;

    public Address() {

        super();

    }

    public Address(String state, String province, String city, String street,

            String zip) {

        super();

        this.state = state;

        this.province = province;

        this.city = city;

        this.street = street;

        this.zip = zip;

    }

    public String getState() {

        return state;

    }

    public void setState(String state) {

        this.state = state;

    }

    public String getProvince() {

        return province;

    }

    public void setProvince(String province) {

        this.province = province;

    }

    public String getCity() {

        return city;

    }

    public void setCity(String city) {

        this.city = city;

    }

    public String getStreet() {

        return street;

    }

    public void setStreet(String street) {

        this.street = street;

    }

    public String getZip() {

        return zip;

    }

    public void setZip(String zip) {

        this.zip = zip;

    }

}

输出：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<shop name="CHMart">

    <number>100000</number>

    <describer>EveryThing</describer>

    <address state="China">

        <province>ZheJiang</province>

        <city>HangZhou</city>

        <street>XiHuRoad</street>

        <zip>310000</zip>

    </address>

    <orders>

        <order orderNumber="LH59900">

            <shopName>Mart</shopName>

            <price>60</price>

            <amount>1</amount>

            <purDate>2016-11-23 14:51:40</purDate>

            <customer name="Jim">

                <gender>male</gender>

                <phoneNo>13699990000</phoneNo>

                <address state="China">

                    <province>ShangHai</province>

                    <city>ShangHai</city>

                    <street>Huang</street>

                    <zip>200000</zip>

                </address>

            </customer>

        </order>

        <order orderNumber="LH59800">

            <shopName>Mart</shopName>

            <price>80</price>

            <amount>1</amount>

            <purDate>2016-11-23 14:51:40</purDate>

            <customer name="David">

                <gender>male</gender>

                <phoneNo>13699991000</phoneNo>

                <address state="China">

                    <province>JiangSu</province>

                    <city>NanJing</city>

                    <street>ZhongYangLu</street>

                    <zip>210000</zip>

                </address>

            </customer>

        </order>

    </orders>

</shop>

***************************

LH59900

Jim

***************************

***************************

LH59800

David

**************************

工具类JaxbUtil.java:

import java.io.StringReader;

import java.io.StringWriter;

import java.util.Collection;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentMap;

import javax.xml.bind.JAXBContext;

import javax.xml.bind.JAXBElement;

import javax.xml.bind.JAXBException;

import javax.xml.bind.Marshaller;

import javax.xml.bind.Unmarshaller;

import javax.xml.bind.annotation.XmlAnyElement;

import javax.xml.namespace.QName;

import org.apache.commons.lang3.Validate;

import com.thinkgem.jeesite.common.utils.Exceptions;

import com.thinkgem.jeesite.common.utils.Reflections;

import com.thinkgem.jeesite.common.utils.StringUtils;

/**

 * 使用Jaxb2.0实现XML<->Java Object的Mapper.

 * 在创建时需要设定所有需要序列化的Root对象的Class.

 * 特别支持Root对象是Collection的情形.

 */

public class JaxbUtil {

        private static ConcurrentMap<Class, JAXBContext> jaxbContexts = new ConcurrentHashMap<Class, JAXBContext>();

        /**

     * Java Object->Xml without encoding.

     */

    @SuppressWarnings("rawtypes")

    public static String toXml(Object root) {

        Class clazz = Reflections.getUserClass(root);

        return toXml(root, clazz, null);

    }

    /**

     * Java Object->Xml with encoding.

     */

    @SuppressWarnings("rawtypes")

    public static String toXml(Object root, String encoding) {

        Class clazz = Reflections.getUserClass(root);

        return toXml(root, clazz, encoding);

    }

    /**

     * Java Object->Xml with encoding.

     */

    @SuppressWarnings("rawtypes")

    public static String toXml(Object root, Class clazz, String encoding) {

        try {

            StringWriter writer = new StringWriter();

            createMarshaller(clazz, encoding).marshal(root, writer);

            return writer.toString();

        } catch (JAXBException e) {

            throw Exceptions.unchecked(e);

        }

    }

    /**

     * Java Collection->Xml without encoding, 特别支持Root Element是Collection的情形.

     */

    @SuppressWarnings("rawtypes")

    public static String toXml(Collection<?> root, String rootName, Class clazz) {

        return toXml(root, rootName, clazz, null);

    }

    /**

     * Java Collection->Xml with encoding, 特别支持Root Element是Collection的情形.

     */

    @SuppressWarnings("rawtypes")

    public static String toXml(Collection<?> root, String rootName, Class clazz, String encoding) {

        try {

            CollectionWrapper wrapper = new CollectionWrapper();

            wrapper.collection = root;

            JAXBElement<CollectionWrapper> wrapperElement = new JAXBElement<CollectionWrapper>(new QName(rootName),

                    CollectionWrapper.class, wrapper);

            StringWriter writer = new StringWriter();

            createMarshaller(clazz, encoding).marshal(wrapperElement, writer);

            return writer.toString();

        } catch (JAXBException e) {

            throw Exceptions.unchecked(e);

        }

    }

    /**

     * Xml->Java Object.

     */

    @SuppressWarnings("unchecked")

    public static <T> T fromXml(String xml, Class<T> clazz) {

        try {

            StringReader reader = new StringReader(xml);

            return (T) createUnmarshaller(clazz).unmarshal(reader);

        } catch (JAXBException e) {

            throw Exceptions.unchecked(e);

        }

    }

    /**

     * 创建Marshaller并设定encoding(可为null).

     * 线程不安全，需要每次创建或pooling。

     */

    @SuppressWarnings("rawtypes")

    public static Marshaller createMarshaller(Class clazz, String encoding) {

        try {

            JAXBContext jaxbContext = getJaxbContext(clazz);

            Marshaller marshaller = jaxbContext.createMarshaller();

            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);

            if (StringUtils.isNotBlank(encoding)) {

                marshaller.setProperty(Marshaller.JAXB_ENCODING, encoding);

            }

            return marshaller;

        } catch (JAXBException e) {

            throw Exceptions.unchecked(e);

        }

    }

    /**

     * 创建UnMarshaller.

     * 线程不安全，需要每次创建或pooling。

     */

    @SuppressWarnings("rawtypes")

    public static Unmarshaller createUnmarshaller(Class clazz) {

        try {

            JAXBContext jaxbContext = getJaxbContext(clazz);

            return jaxbContext.createUnmarshaller();

        } catch (JAXBException e) {

            throw Exceptions.unchecked(e);

        }

    }

    @SuppressWarnings("rawtypes")

    protected static JAXBContext getJaxbContext(Class clazz) {

        Validate.notNull(clazz, "'clazz' must not be null");

        JAXBContext jaxbContext = jaxbContexts.get(clazz);

        if (jaxbContext == null) {

            try {

                jaxbContext = JAXBContext.newInstance(clazz, CollectionWrapper.class);

                jaxbContexts.putIfAbsent(clazz, jaxbContext);

            } catch (JAXBException ex) {

                throw new RuntimeException("Could not instantiate JAXBContext for class [" + clazz + "]: "

                        + ex.getMessage(), ex);

            }

        }

        return jaxbContext;

    }

    /**

     * 封装Root Element 是 Collection的情况.

     */

    public static class CollectionWrapper {

        @XmlAnyElement

        protected Collection<?> collection;

    }

}

测试：

String s = JaxbUtil.toXml(shop);

System.out.println(s);

输出：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<shop name="CHMart">

    <number>100000</number>

    <describer>EveryThing</describer>

    <address state="China">

        <province>ZheJiang</province>

        <city>HangZhou</city>

        <street>XiHuRoad</street>

        <zip>310000</zip>

    </address>

    <orders>

        <order orderNumber="LH59800">

            <shopName>Mart</shopName>

            <price>80</price>

            <amount>1</amount>

            <purDate>2016-11-23 14:54:39</purDate>

            <customer name="David">

                <gender>male</gender>

                <phoneNo>13699991000</phoneNo>

                <address state="China">

                    <province>JiangSu</province>

                    <city>NanJing</city>

                    <street>ZhongYangLu</street>

                    <zip>210000</zip>

                </address>

            </customer>

        </order>

        <order orderNumber="LH59900">

            <shopName>Mart</shopName>

            <price>60</price>

            <amount>1</amount>

            <purDate>2016-11-23 14:54:39</purDate>

            <customer name="Jim">

                <gender>male</gender>

                <phoneNo>13699990000</phoneNo>

                <address state="China">

                    <province>ShangHai</province>

                    <city>ShangHai</city>

                    <street>Huang</street>

                    <zip>200000</zip>

                </address>

            </customer>

        </order>

    </orders>

</shop>
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