java bean与xml相互转换

java bean 与xml相互转换的方式有多种。这里介绍jaxb2.0和xstream的方式。首先需要引入xstream和jaxb2.0的jar包

<dependency>
<groupId>com.thoughtworks.xstream</groupId>
<artifactId>xstream</artifactId>
<version>1.4.5</version>
</dependency>
<dependency>
<groupId>javax.xml.bind</groupId>
<artifactId>jaxb-api</artifactId>
<version>2.2.3</version>
</dependency>

xstream方式

1. 实体类定义

1.1Book.java

public class Book {
@XStreamAlias("Name")//通过注解的方式重定义节点名称
private String name;
private String author;

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getAuthor() {
return author;
}

public void setAuthor(String author) {
this.author = author;
}

}

1.2Address.java

@XStreamAlias("Address")
public class Address {
private String street;

public String getStreet() {
return street;
}

public void setStreet(String street) {
this.street = street;
}
}

1.3Student.java

public class Student {

@XStreamAlias("Name")
private String name;
//自定义的类型转换器
@XStreamConverter(value=MyDateConverter.class,strings={"yyyyMMddHHmmss"})
@XStreamAlias("Birth")
private Date birthday;
@XStreamAlias("Address")
private Address address;
@XStreamAlias("books")
private List<Book> list;

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public Date getBirthday() {
return birthday;
}

public void setBirthday(Date birthday) {
this.birthday = birthday;
}

public Address getAddress() {
return address;
}

public void setAddress(Address address) {
this.address = address;
}

public List<Book> getList() {
return list;
}

public void setList(List<Book> list) {
this.list = list;
}
}

2. 自定义类型转换器

/**
* 通过注解对不同Date格式的支持
* <p/>
* XStream中DateConverter，它默认支持的格式是：yyyy-MM-dd HH:mm:ss.S 'UTC'
* 通过@XStreamConverter注解可以定义自己的Date格式
* <p/>
* DateConverter(String defaultFormat, String[] acceptableFormats, TimeZone timeZone)
* Construct a DateConverter with a given TimeZone
*/
public class MyDateConverter extends DateConverter {

public MyDateConverter(String dateFormat) {

super(dateFormat, new String[]{dateFormat}, TimeZone.getTimeZone("GMT+8"));
}
}

3. xstream 转换工具类

工具类实现bean 和xml 之间相互转换

import com.hgsoft.yfzx.consumption.pos.entity.*;
import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.xml.StaxDriver;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;

public abstract class XStreamUtil {

private final static Logger logger = LoggerFactory.getLogger(XStreamUtil.class);

private final static StaxDriver domDriver = new StaxDriver();
private final static XStream o2x = new XStream(domDriver);
private final static XStream x2o = new XStream(domDriver);

private final static void initO2X() {
List<Class> basic = new ArrayList(3);
//需要把用到的实体类都添加，否则不会使用注解方式来定义别名，但是这样的方式不好。代码侵入大
basic.add(Student.class);
basic.add(Address.class);
basic.add(Book.class);
Class[] clazzs = new Class[basic.size()];
////设置使用注解方式来处理别名信息
o2x.processAnnotations(basic.toArray(clazzs));
}

private final static void initX2O() {
List<Class> basic = new ArrayList(3);
basic.add(Student.class);
basic.add(Address.class);
basic.add(Book.class);
Class[] clazzs = new Class[basic.size()];
x2o.processAnnotations(basic.toArray(clazzs));
}

static {
initO2X();
initX2O();
}

/**
* 实体类转xml字符串
* @param obj 实体类
* @return
* @throws Exception
*/
public static String object2Xml(Object obj) throws Exception {
if (null == obj) {
return null;
}
StringWriter writer = new StringWriter();
o2x.toXML(obj, writer);
return writer.toString();
}

/**
*
* xml字符串转实体类
* @param xml 字符串
* @param clazz 实体类
* @return
*/
public static Object xml2Object(String xml, Class<?> clazz) {
if (null == xml || "".equals(xml.trim())) {
return null;
}
Object obj = null;
try {
obj = x2o.fromXML(xml, clazz.newInstance());
} catch (Exception e) {
logger.error(e.getMessage(), e);
}
return obj;
}
}

jaxb2.0方式

1. 实体类定义

1.1Summary.java

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;

@XmlRootElement(name = "Message")//表示该类是XML根元素  name属性定义了XML根元素的元素名
@XmlType(propOrder = { "authInfo", "summaryDetail" })
//定义XML的生成规则 propOrder 属性在xml里的出现顺序
public class Summary {

private AuthInfo authInfo;
private SummaryDetail summaryDetail;

@XmlElement(name = "AuthInfo")//定义生成后的xml的属性名，这个和xstream区别是这个写在get方法上
public AuthInfo getAuthInfo() {
return authInfo;
}

public void setAuthInfo(AuthInfo authInfo) {
this.authInfo = authInfo;
}

@XmlElement(name = "Detail")
public SummaryDetail getSummaryDetail() {
return summaryDetail;
}

public void setSummaryDetail(SummaryDetail summaryDetail) {
this.summaryDetail = summaryDetail;
}
}

1.2 AuthInfo.java

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlType;

@XmlType(propOrder = { "username", "password"})//节点显示的顺序
public class AuthInfo {

private String username;
private String password;

@XmlElement(name = "UserName")
public String getUsername() {
return username;
}

public void setUsername(String username) {
this.username = username;
}

@XmlElement(name = "Password")
public String getPassword() {
return password;
}

public void setPassword(String password) {
this.password = password;
}
}

1.3 SummaryDetail.java

import com.hgsoft.yfzx.consumption.pos.util.JaxbBigDecimalAdapter;
import com.hgsoft.yfzx.consumption.pos.util.JaxbDateAdapter;
import com.hgsoft.yfzx.consumption.pos.util.JaxbThirdDateAdapter;
import com.thoughtworks.xstream.annotations.XStreamAlias;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlType;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
import java.io.Serializable;
import java.math.BigDecimal;
import java.util.Date;

@XmlType(propOrder = { "serviceId", "oprDt","bizCount" ,"bizAmount"})
public class SummaryDetail {

private String serviceId;//服务商编号
private Date oprDt;//交易时间
private Integer bizCount;//交易总条数
private BigDecimal bizAmount;//交易总金额

@XmlElement(name = "ServiceId")
public String getServiceId() {
return serviceId;
}

public void setServiceId(String serviceId) {
this.serviceId = serviceId;
}

@XmlElement(name = "OprDt")
@XmlJavaTypeAdapter(JaxbThirdDateAdapter.class)
public Date getOprDt() {
return oprDt;
}

public void setOprDt(Date oprDt) {
this.oprDt = oprDt;
}

@XmlElement(name = "BizCount")
public Integer getBizCount() {
return bizCount;
}

public void setBizCount(Integer bizCount) {
this.bizCount = bizCount;
}

@XmlElement(name = "BizAmount")
@XmlJavaTypeAdapter(JaxbBigDecimalAdapter.class)//自定义类型转换器
public BigDecimal getBizAmount() {
return bizAmount;
}

public void setBizAmount(BigDecimal bizAmount) {
this.bizAmount = bizAmount;
}
}

2. 自定义转换器

import javax.xml.bind.annotation.adapters.XmlAdapter;
import java.math.BigDecimal;
import java.text.DecimalFormat;

/**
* BigDeciaml保留两位小数
*/
public class JaxbBigDecimalAdapter extends XmlAdapter<String, BigDecimal> {

private DecimalFormat df = new DecimalFormat("#0.00");

@Override
public BigDecimal unmarshal(String v) throws Exception {
BigDecimal a = new BigDecimal(v);
a = a.setScale(2, BigDecimal.ROUND_HALF_UP);
return a;
}

@Override
public String marshal(BigDecimal v) throws Exception {
if (v != null) {
return df.format(v);
}
return null;
}

}

import javax.xml.bind.annotation.adapters.XmlAdapter;
import java.text.SimpleDateFormat;
import java.util.Date;

public class JaxbThirdDateAdapter extends XmlAdapter<String, Date> {

private SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

@Override
public Date unmarshal(String v) throws Exception {
return sdf.parse(v);
}

@Override
public String marshal(Date v) throws Exception {
return sdf.format(v);
}
}

3. 转换工具类

其一

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;

/**
* XML的帮助类
*
* @version v1.0
*/
public class XmlHelper {
/**
* 将自定义数据对象转化为XML字符串
*
* @param clazz  自定义数据类型
* @param object 自定义数据对象
* @return XML字符串
* @throws JAXBException 异常
*/
public static String objectToXML(Class clazz, Object object)
throws JAXBException {
String xml = null;
JAXBContext context = JAXBContext.newInstance(clazz);
Marshaller m = context.createMarshaller();
m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
Writer w = new StringWriter();
m.marshal(object, w);
xml = w.toString();
return xml;
}

/**
* 将XML字符串转化为自定义数据对象
*
* @param clazz 自定义数据类型
* @param xml   XML字符串
* @return 自定义数据对象
* @throws JAXBException 异常
*/
public static Object xmlToObject(Class clazz, String xml)
throws JAXBException {
JAXBContext context = JAXBContext.newInstance(clazz);
Unmarshaller um = context.createUnmarshaller();
return um.unmarshal(new StringReader(xml));
}
}

其二

import org.apache.commons.lang.StringUtils;

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 java.io.StringReader;
import java.io.StringWriter;
import java.util.Collection;

/**
* 使用Jaxb2.0实现XML<->Java Object的Binder.
* <p/>
* 特别支持Root对象是List的情形.
*
* @author
*/
public class JaxbUtil {
// 多线程安全的Context.
private JAXBContext jaxbContext;

/**
* @param types 所有需要序列化的Root对象的类型.
*/
public JaxbUtil(Class<?>... types) {
try {
jaxbContext = JAXBContext.newInstance(types);
} catch (JAXBException e) {
throw new RuntimeException(e);
}
}

/**
* Java Object->Xml.
*/
public String toXml(Object root, String encoding) {
try {
StringWriter writer = new StringWriter();
createMarshaller(encoding).marshal(root, writer);
return writer.toString();
} catch (JAXBException e) {
throw new RuntimeException(e);
}
}

/**
* Java Object->Xml, 特别支持对Root Element是Collection的情形.
*/
@SuppressWarnings("unchecked")
public String toXml(Collection root, String rootName, 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(encoding).marshal(wrapperElement, writer);

return writer.toString();
} catch (JAXBException e) {
throw new RuntimeException(e);
}
}

/**
* Xml->Java Object.
*/
@SuppressWarnings("unchecked")
public <T> T fromXml(String xml) {
try {
StringReader reader = new StringReader(xml);
return (T) createUnmarshaller().unmarshal(reader);
} catch (JAXBException e) {
throw new RuntimeException(e);
}
}

/**
* Xml->Java Object, 支持大小写敏感或不敏感.
*/
@SuppressWarnings("unchecked")
public <T> T fromXml(String xml, boolean caseSensitive) {
try {
String fromXml = xml;
if (!caseSensitive)
fromXml = xml.toLowerCase();
StringReader reader = new StringReader(fromXml);
return (T) createUnmarshaller().unmarshal(reader);
} catch (JAXBException e) {
throw new RuntimeException(e);
}
}

/**
* 创建Marshaller, 设定encoding(可为Null).
*/
public Marshaller createMarshaller(String encoding) {
try {
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 new RuntimeException(e);
}
}

/**
* 创建UnMarshaller.
*/
public Unmarshaller createUnmarshaller() {
try {
return jaxbContext.createUnmarshaller();
} catch (JAXBException e) {
throw new RuntimeException(e);
}
}

/**
* 封装Root Element 是 Collection的情况.
*/
public static class CollectionWrapper {
@SuppressWarnings("unchecked")
@XmlAnyElement
protected Collection collection;
}
}

参考文章

jaxb使用教程

http://blog.csdn.net/baple/article/details/18219099