JAXB 解决XML与JavaBean的互换
###声明
版权所有,转载请注明出处
###文章概要
基于JAXB2 的xml bean 转换工具
###正文
####运行环境
JDK,Dom4j
####JAXB 实现xml和javabean的编组和解组
/**
* 基于JAXB2 的xml bean 转换工具
* @author Administrator
*
*/
public class JaxbUtil {
public static String bean2xml(Object bean){
try {
JAXBContext context = JAXBContext.newInstance(bean.getClass());
Marshaller marshaller = context.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT,true);
Writer writer = new StringWriter();
marshaller.marshal(bean,writer);
return writer.toString();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public static <T> T xml2Bean(String xml,Class<T> clazz){
T t = null;
try {
JAXBContext context = JAXBContext.newInstance(clazz);
Unmarshaller unmarshaller = context.createUnmarshaller();
t = (T) unmarshaller.unmarshal(new StringReader(xml));
return t;
} catch (Exception e) {
e.printStackTrace();
}
return t;
}
}
测试用例: JavaBean
@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement()
@XmlType(propOrder = {})
public class GeneralMessageHead implements MessageHead{
/**
*
*/
private String RequestType;
private String CompanyCode;
private String SerialNo;
private String TimeStamp;
private String DataType;
//省略getter和setter
}
测试类
public class JaxbUtilTest {
@Test
public void testBean2xml() {
String xml = JaxbUtil.bean2xml(TestHandel.getRequestHead());
System.out.println(xml);
}
@Test
public void testXml2Bean() {
String xml = " <generalMessageHead> <RequestType>HisUpload</RequestType> <CompanyCode>000000</CompanyCode> <SerialNo>201508251502120123</SerialNo> <TimeStamp>20150102010101</TimeStamp> <DataType>P</DataType> </generalMessageHead>";
GeneralMessageHead a = JaxbUtil.xml2Bean(xml,GeneralMessageHead.class);
System.out.println(a.getCompanyCode());
}
}
测试运行结果
000000
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<generalMessageHead>
<RequestType>HisUpload</RequestType>
<CompanyCode>000000</CompanyCode>
<SerialNo>201508251502120123</SerialNo>
<TimeStamp>20150102010101</TimeStamp>
<DataType>P</DataType>
</generalMessageHead>
JAXB 常用annotation说明:
@XmlType @XmlElement @XmlRootElement @XmlAttribute @XmlAccessorType @XmlAccessorOrder @XmlTransient @XmlJavaTypeAdapter
复杂Bean示例
@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement()
@XmlType(propOrder = {})
public enum EnumBean {
MON,TUE,WED,THU,FRI,SAT,SUN;
}
@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement()
@XmlType(propOrder = {})
public class SimpleBean {
private String stringType;
private double doubleType;
public String getStringType() {
return stringType;
}
public void setStringType(String stringType) {
this.stringType = stringType;
}
public double getDoubleType() {
return doubleType;
}
public void setDoubleType(double doubleType) {
this.doubleType = doubleType;
}
}
/** * 该Bean包含了: * 引用对象 * 基本数据类型 * 枚举 * 数组 * 集合[List,Set,Map] * * * */ /** * @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,有四个枚举值: * 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(未加注解的)属性都不映射为xml的元素 * * */ @XmlAccessorType(XmlAccessType.FIELD) @XmlRootElement() @XmlType(propOrder = {}) /** @XmlAccessorOrder用于对java对象生成的xml元素进行排序.它有两个属性值： XmlAccessOrder.ALPHABETICAL：对生成的xml元素按字母书序排序 XmlAccessOrder.UNDEFINED:不排序 */ //@XmlAccessorOrder(XmlAccessOrder.ALPHABETICAL) public class ComplexBean { @XmlElement(name="SimpleBean")//修改元素名称 SimpleBean otherBean; @XmlAttribute(name="intType")//使其为根节点属性 int intType; @XmlTransient//忽略属性 long longType; float floatType; double doubleType; boolean booleanType; char charType; String stringType; @XmlJavaTypeAdapter(value=jaxb.FormatDate.class)//自定义转换 Date dateType; EnumBean enumType; String[] stringArrayType; SimpleBean[] simpleBeanArrayType; List<String> stringListType; Set<String> stringSetType; Map<String,String> stringMapType; Map<String,SimpleBean> beanMapTyep; //省略getter和setter }
public class FormatDate extends XmlAdapter<String,Date> {
private SimpleDateFormat sdf = new SimpleDateFormat("YYYY/MM/dd HH:mm:ss");
@Override
public String marshal(Date v) throws Exception {
return sdf.format(v);
}
@Override
public Date unmarshal(String v) throws Exception {
return sdf.parse(v);
}
}
测试代码
SimpleBean simpleBean = new SimpleBean();
simpleBean.setStringType("string");
simpleBean.setDoubleType(1.11);
ComplexBean complexBean = new ComplexBean();
complexBean.setOtherBean(simpleBean);
complexBean.setIntType(1);
complexBean.setLongType(2);
complexBean.setFloatType(3);
complexBean.setDoubleType(4.23);
complexBean.setCharType('5');
complexBean.setBooleanType(true);
complexBean.setStringType("string");
complexBean.setDateType(new Date());
complexBean.setEnumType(EnumBean.MON);
String[] stringArrayType = new String[]{"str1","str2","str3"};
SimpleBean[] simpleBeanArrayType = new SimpleBean[]{simpleBean};
complexBean.setStringArrayType(stringArrayType);
complexBean.setSimpleBeanArrayType(simpleBeanArrayType);
List<String> stringListType = new ArrayList<String>();
stringListType.add("list1");stringListType.add("list2");
Set<String> stringSetType = new HashSet<String>(stringListType);
Map<String,String> stringMapType = new HashMap<>();
stringMapType.put("key","value");
complexBean.setStringListType(stringListType);
complexBean.setStringSetType(stringSetType);
complexBean.setStringMapType(stringMapType);
Map<String,SimpleBean> beanMapTyep = new HashMap<>();
beanMapTyep.put("key",simpleBean);
complexBean.setBeanMapTyep(beanMapTyep);
String xml = JaxbUtil.bean2xml(complexBean);
System.out.println(xml);
使用Dom4j解析XML
对我来说,使用JDK的XML解析类很不方便.为了解决复杂的XML Bean组合与拆分问题,我通常使用Dom4j提取出Bean对应的DOM元素节点,然后再用JAXB解析为Bean实例.
反过来,多个Bean组合的XML文档,先使用JAXB将Bean转为XML,在使用Dom4j组合这些XML.
Dom4j很方便的一点就是可以使用XPath直接,准确的定位元素节点.
###参考资料
