使用JAXB包實(shí)現(xiàn)bean和xml的互轉(zhuǎn)

前言

由于項(xiàng)目需要,調(diào)用第三方接口,接口返回格式為xml格式。遂用上了javax.xml 用于實(shí)現(xiàn)Bean和xml互轉(zhuǎn)
首先我們看看工具類XmlUtil

  /**
     * XML轉(zhuǎn)對(duì)象
     *
     * @param xmlStr xml字串
     * @param t      對(duì)象類型
     * @return 對(duì)象
     */
    public static <T> T xmlToBean(String xmlStr, Class<T> t) {
        try {
        //特殊字符不讓其轉(zhuǎn)義,不然會(huì)報(bào)錯(cuò)
          if (xmlStr.contains("&#xB;")) {
                xmlStr = xmlStr.replace("&#xB;","<![CDATA[&#xB;]]>");
            }
            JAXBContext context = JAXBContext.newInstance(t);
            Unmarshaller unmarshaller = context.createUnmarshaller();
            StringReader reader = new StringReader(xmlStr);
            SAXParserFactory sax = SAXParserFactory.newInstance();
            //設(shè)置忽略命名空間
            sax.setNamespaceAware(false);
            XMLReader xmlReader = sax.newSAXParser().getXMLReader();
            Source source = new SAXSource(xmlReader, new InputSource(reader));
            return (T) unmarshaller.unmarshal(source);
        } catch (JAXBException e) {
            e.printStackTrace();
        } catch (SAXException e) {
            e.printStackTrace();
        } catch (ParserConfigurationException e) {
            e.printStackTrace();
        }
        return null;
    }
    
        /**
     * 對(duì)象轉(zhuǎn)XML
     *
     * @param obj 對(duì)象
     * @return 字符串
     */
    public static String beanToXml(Object obj) {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        try {
            JAXBContext context = JAXBContext.newInstance(obj.getClass());
            Marshaller marshaller = context.createMarshaller();
//            marshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);
            marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.FALSE);
            marshaller.marshal(obj, out);
            try {
                return new String(out.toByteArray(), "UTF-8");
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
        } catch (JAXBException e) {
            e.printStackTrace();
        }
        return null;
    }


代碼解釋

marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.FALSE);

 
如果為true的話,則不會(huì)生成<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
使用的Bean

@XmlRootElement(name = "requestXML")
@XmlAccessorType(XmlAccessType.FIELD)
public class TelefenCommonVO {
    /**
     * 應(yīng)用編碼
     */
    @XmlElement(name = "AppID")
    private String appid;
    /**
     * 接入業(yè)務(wù)
     */
    private String SPID;
    /**
     * 請(qǐng)求流水
     */
    private String RequestNo;
    /**
     * 請(qǐng)求時(shí)間
     */
    private String RequestTime;
    /**
     * 簽名
     */
    @XmlTransient
    private String Sign;

    public String getAppid() {
        return appid;
    }

    public void setAppid(String appid) {
        this.appid = appid;
    }

    public String getSPID() {
        return SPID;
    }

    public void setSPID(String SPID) {
        this.SPID = SPID;
    }

    public String getRequestNo() {
        return RequestNo;
    }

    public void setRequestNo(String requestNo) {
        RequestNo = requestNo;
    }

    public String getRequestTime() {
        return RequestTime;
    }

    public void setRequestTime(String requestTime) {
        RequestTime = requestTime;
    }

    public String getSign() {
        return Sign;
    }

    public void setSign(String sign) {
        this.Sign = sign;
    }

    public TelefenCommonVO() {
    }

    protected TelefenCommonVO(Builder builder) {
        this.appid = builder.AppID;
        this.SPID = builder.SPID;
        this.RequestNo = builder.RequestNo;
        this.RequestTime = builder.RequestTime;
        this.Sign = builder.Sign;
    }
      public static final class Builder{
        /**
         * 應(yīng)用編碼
         */
        private String AppID;
        /**
         * 接入業(yè)務(wù)
         */
        private String SPID;
        /**
         * 請(qǐng)求流水
         */
        private String RequestNo;
        /**
         * 請(qǐng)求時(shí)間
         */
        private String RequestTime;
        /**
         * 簽名
         */
        private String Sign;
        public Builder setAppID(String appID) {
            this.AppID = appID;
            return this;
        }
        public Builder setSPID(String SPID){
            this.SPID = SPID;
            return this;
        }
        public Builder setRequestNo(String requestNo){
            this.RequestNo = requestNo;
            return this;
        }
        public Builder setRequestTime(String requestTime){
            this.RequestTime = requestTime;
            return this;
        }
        public Builder setSign(String sign){
            this.Sign = sign;
            return this;
        }
        public TelefenCommonVO build() {
            return new TelefenCommonVO(this);
        }
    }
}
    
 

代碼解釋

    @XmlRootElement(name = "requestXML") 注解是指定xml的根節(jié)點(diǎn),作用在類上
    @XmlAccessorType 用于指定有java對(duì)象生成xml文件時(shí)對(duì)java對(duì)象屬性的訪問方式。 它的屬性值是XmlAccessType的四個(gè)枚舉值。分別是:

    XmlAccessType.FIELD java 對(duì)象中的所有成員變量
    XmlAccessType.PROPERTY java對(duì)象中所有通過(guò)getter/setter 方式訪問的成員變量。
    XmlAccessType.PUBLIC_MEMBER java 對(duì)象中所有的public 訪問權(quán)限的成員變量和通過(guò)getter/setter方式訪問的成員變量 。
    XmlAccessType.NONE java對(duì)象的所有屬性都不映射為XML元素

    @XmlElement
    該注解用在類的屬性上。用于將屬性映射為xml的子節(jié)點(diǎn),可通過(guò)在后面配置name屬性值類改變java屬性在xml文件中的名稱。例如:

    @XmlElement(name = "AppID")
    private String appid;

轉(zhuǎn)化成xml為<AppID></AppID> 而不是<appid></appid>
5. @XmlAccessorOrder
用于對(duì)java 對(duì)象生成的xml元素進(jìn)行排序。它有兩個(gè)屬性值:
 AccessorOrder.ALPHABETICAL:對(duì)生成的xml元素按字母順序排序;
 XmlAccessOrder.UNDEFINED:不進(jìn)行排序
6. @XmlTransient
用于標(biāo)示在由java對(duì)象映射xml時(shí),忽略此屬性。即,在生成的xml文件中不出現(xiàn)此元素。
7. @XmlElementWrapper
在注解最外面再加一層,可用于POJO中包含List的屬性中,例如:
待轉(zhuǎn)化sql

<responseXML>
  <Details>
    <Detail>
      <CardNo>11111</CardNo>
      <CardPwd>2222</CardPwd>
      <CodeURL/>
    </Detail>
  </Details>
</responseXML>



對(duì)應(yīng)的Bean

@XmlRootElement(name ="responseXML")
@XmlAccessorType(XmlAccessType.FIELD)
public class OrderPayRespVO  {

    /**
     * 卡信息列表
     */
    @XmlElementWrapper(name="Details")
    @XmlElement(name = "Detail")
    private List<Detail> Details;
    省略get,set方法
}


@XmlRootElement(name = "Detail")
@XmlAccessorType(XmlAccessType.FIELD)
public class Detail {
    /**
     *  卡號(hào)
     */
    private String CardNo;
    /**
     * 卡密
     */
    private String CardPwd;
    /**
     * 短鏈
     */
    private String CodeURL;
        省略get,set方法

    }


轉(zhuǎn)化之后

OrderPayRespVO{Details=[Detail{CardNo='11111', CardPwd='2222', CodeURL=''}]}

    此外該Bean 還使用到了建造者設(shè)計(jì)模式來(lái)實(shí)現(xiàn)屬性的鏈?zhǔn)秸{(diào)用。

測(cè)試代碼

  public static void main(String[] args) throws IOException {
        TelefenCommonVO commonVO = new TelefenCommonVO.Builder()
                .setAppID("1112")
                .setRequestNo("3333")
                .setSPID("444")
                .setRequestTime("20180823")
                .setSign("qqwqwqwq1121")
                .build();

        String xml = beanToXml(commonVO);
        System.out.println("返回的xml為="+xml);
        TelefenCommonVO commonVO1 = xmlToBean(xml, TelefenCommonVO.class);
        System.out.println("轉(zhuǎn)化后的bean為="+commonVO1.toString());


    }


運(yùn)行結(jié)果

返回的xml為=<?xml version="1.0" encoding="UTF-8" standalone="yes"?><requestXML><AppID>1112</AppID><SPID>444</SPID><RequestNo>3333</RequestNo><RequestTime>20180823</RequestTime></requestXML>
轉(zhuǎn)化后的bean為=TelefenCommonVO{appid='1112', SPID='444', RequestNo='3333', RequestTime='20180823', Sign='null'}





作者:碼農(nóng)飛哥
微信公眾號(hào):碼農(nóng)飛哥