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