一.Jaxb处理java对象和xml之间转换常用的annotation有:
- @XmlType
- @XmlElement
- @XmlRootElement
- @XmlAttribute
- @XmlAccessorType
- @XmlAccessorOrder
- @XmlTransient
- @XmlJavaTypeAdapter
二.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。
2.@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:
3.@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:
@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement
public class Address {}
4.@XmlAttribute
private String state;
5.@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。
6.@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
7.@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。
8.@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);
}
三:demo
xml如下:
<?xml version="1.0" encoding="UTF-8"?>
<result>
<status>
<![CDATA[1]]>
</status>
<totalNum>
<![CDATA[5]]>
</totalNum>
<views>
<view>
<viewId>
<![CDATA[gzclss]]>
</viewId>
<viewName>
<![CDATA[长隆水上乐园]]>
</viewName>
<cityName>
<![CDATA[番禺]]>
</cityName>
<viewAddress>
<![CDATA[广州番禺迎宾路长隆旅游度假区 ]]>
</viewAddress>
<viewNum>
<![CDATA[8]]>
</viewNum>
<viewLongitude>
<![CDATA[113.31577]]>
</viewLongitude>
<viewLatitude>
<![CDATA[22.99972]]>
</viewLatitude>
</view>
<view>
<viewId>
<![CDATA[hnzwy]]>
</viewId>
<viewName>
<![CDATA[华南植物园]]>
</viewName>
<cityName>
<![CDATA[天河区]]>
</cityName>
<viewAddress>
<![CDATA[广州市天河区兴科路723号]]>
</viewAddress>
<viewNum>
<![CDATA[7]]>
</viewNum>
<viewLongitude>
<![CDATA[113.36001]]>
</viewLongitude>
<viewLatitude>
<![CDATA[23.18487]]>
</viewLatitude>
</view>
<view>
<viewId>
<![CDATA[view_28841]]>
</viewId>
<viewName>
<![CDATA[商家测试]]>
</viewName>
<cityName>
<![CDATA[珠海]]>
</cityName>
<viewAddress>
<![CDATA[测试专用]]>
</viewAddress>
<viewNum>
<![CDATA[5]]>
</viewNum>
<viewLongitude>
<![CDATA[]]>
</viewLongitude>
<viewLatitude>
<![CDATA[]]>
</viewLatitude>
</view>
<view>
<viewId>
<![CDATA[zygbdst]]>
</viewId>
<viewName>
<![CDATA[中央电视塔]]>
</viewName>
<cityName>
<![CDATA[北京]]>
</cityName>
<viewAddress>
<![CDATA[北京市海淀区西三环中路11号]]>
</viewAddress>
<viewNum>
<![CDATA[3]]>
</viewNum>
<viewLongitude>
<![CDATA[116.29944]]>
</viewLongitude>
<viewLatitude>
<![CDATA[39.91899]]>
</viewLatitude>
</view>
<view>
<viewId>
<![CDATA[clyjdw]]>
</viewId>
<viewName>
<![CDATA[长隆野生动物世界(爸爸去哪儿电影拍摄地)]]>
</viewName>
<cityName>
<![CDATA[番禺]]>
</cityName>
<viewAddress>
<![CDATA[广州市番禺区大石镇迎宾路]]>
</viewAddress>
<viewNum>
<![CDATA[3]]>
</viewNum>
<viewLongitude>
<![CDATA[113.32398]]>
</viewLongitude>
<viewLatitude>
<![CDATA[23.00275]]>
</viewLatitude>
</view>
</views>
</result>
分析xml结构可得出,可以设置对应的两个javabean,分别为View.java和ViewInfo.java,代码如下:
View.java:
import java.util.List;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlElementWrapper;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(propOrder = {"status","totalNum","views"})
@XmlRootElement(name = "result")
public class View {
@XmlElement(name = "status")
public String status;
@XmlElement(name = "totalNum")
public String totalNum;
@XmlElementWrapper(name = "views")//嵌套一层封装好的结合wrapper,xml节点
@XmlElement(name = "view")//xml节点
public List<ViewInfo> views;
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
public String getTotalNum() {
return totalNum;
}
public void setTotalNum(String totalNum) {
this.totalNum = totalNum;
}
public List<ViewInfo> getViews() {
return views;
}
public void setViews(List<ViewInfo> views) {
this.views = views;
}
}
ViewInfo.java
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(propOrder = {"viewId","viewName","cityName","viewAddress","viewNum","viewLongitude","viewLatitude"})
@XmlRootElement(name = "view")
public class ViewInfo {
@XmlElement(name = "viewId")
public String viewId;
@XmlElement(name = "viewName")
public String viewName;
@XmlElement(name = "cityName")
public String cityName;
@XmlElement(name = "viewAddress")
public String viewAddress;
@XmlElement(name = "viewNum")
public String viewNum;
@XmlElement(name = "viewLongitude")
public String viewLongitude;
@XmlElement(name = "viewLatitude")
public String viewLatitude;
public String getViewId() {
return viewId;
}
public void setViewId(String viewId) {
this.viewId = viewId;
}
public String getViewName() {
return viewName;
}
public void setViewName(String viewName) {
this.viewName = viewName;
}
public String getCityName() {
return cityName;
}
public void setCityName(String cityName) {
this.cityName = cityName;
}
public String getViewAddress() {
return viewAddress;
}
public void setViewAddress(String viewAddress) {
this.viewAddress = viewAddress;
}
public String getViewNum() {
return viewNum;
}
public void setViewNum(String viewNum) {
this.viewNum = viewNum;
}
public String getViewLongitude() {
return viewLongitude;
}
public void setViewLongitude(String viewLongitude) {
this.viewLongitude = viewLongitude;
}
public String getViewLatitude() {
return viewLatitude;
}
public void setViewLatitude(String viewLatitude) {
this.viewLatitude = viewLatitude;
}
}
转化工具:ParseUtil.java
package com.mangocity.ziwoyou.util;
import java.io.ByteArrayInputStream;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Created by zhanghaojia on 14-7-14.
* ParseUtil工具类主要用于xml解析为Object
*/
public class ParseUtil<T> {
protected static final Log logger = LogFactory.getLog(ParseUtil.class);
/**
* 将xml数据解析成一个Object
*
* @param xmlStr 需要解析的xml字符串
* @param clazz 需要映射到的类
* @return 解析结果
*/
@SuppressWarnings("unchecked")
public T xmlToObject(String xmlStr,Class clazz) {
JAXBContext jaxbContext = null;
T obj = null;
if (xmlStr == null || "nil".equals(xmlStr))
{
return null;
}
//logger.info("xmlStr 1 = " + xmlStr);
try {
String fileEncode = System.getProperty("file.encoding");
if (fileEncode != null && fileEncode.equals("GBK")) {
int xml = xmlStr.indexOf("utf-8");
if(xml != 0) {
xmlStr = xmlStr.replace("utf-8","gbk");
}
}
//logger.info("xmlStr 2 =|" + xmlStr + "|");
jaxbContext = JAXBContext.newInstance(clazz);
Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
obj = (T) unmarshaller.unmarshal(new ByteArrayInputStream(xmlStr.getBytes()));
} catch (JAXBException e) {
e.printStackTrace();
}
return obj;
}
}
测试:
public static void main(String[] args) {
ParseUtil<View> imageListDataParseUtil = new ParseUtil<View>();
View view = imageListDataParseUtil.xmlToObject(xml,View.class);
for (ViewInfo vi : view.getViews()) {
System.out.println(vi.getCityName());
}
}
结果:
番禺
天河区
珠海
北京
番禺
