前言
在微信訂閱號和支付寶生活號日常開發中,我們會涉及到對象和XML之間的相互轉換。
比如我們可以利用StringBuilder去直接拼接來構造XML
/**
* 構造基礎的響應消息
*
* @return
*/
public static String buildBaseAckMsg(String fromUserId) {
StringBuilder sb = new StringBuilder();
sb.append("<XML>");
sb.append("<ToUserId><![CDATA[" + fromUserId + "]]></ToUserId>");
sb.append("<AppId><![CDATA[" + AlipayServiceEnvConstants.APP_ID + "]]></AppId>");
sb.append("<CreateTime>" + Calendar.getInstance().getTimeInMillis() + "</CreateTime>");
sb.append("<MsgType><![CDATA[ack]]></MsgType>");
sb.append("</XML>");
return sb.toString();
}
作爲像我這麼懶得程序員,肯定會去找大佬寫好的輪子,這就是我和XStream
相遇的契機。下面我們一起走進XStream
;
一.關於 XStream
Xstream 是一個簡單的庫,用於將對象序列化爲 XML 然後再序列化回來。
二.簡單入門
2.1 創建要序列化的類
這裏有幾個簡單的類,XStream 可以將這些類的實例轉換爲 XML,然後再轉換回來。
public class Person {
private String firstname;
private String lastname;
private PhoneNumber phone;
private PhoneNumber fax;
// ... constructors and methods
}
public class PhoneNumber {
private int code;
private String number;
// ... constructors and methods
}
注意: 注意這些字段是私有的。Xstream 不關心字段的可見性。不需要getters or setters
。此外,XStream 並不限制你擁有一個默認構造函數
。
2.2 初始化 XStream
引入依賴
<dependency>
<groupId>com.thoughtworks.xstream</groupId>
<artifactId>xstream</artifactId>
<version>1.4.10</version>
</dependency>
要使用 XStream,只需實例化 XStream 類:
XStream xstream = new XStream();
2.3.將序列化對象轉爲xml
讓我們創建一個 Person 實例並填充它的字段:
Person person = new Person("Joe", "milo");
person.setPhone(new PhoneNumber(123,"1234-456"));
person.setFax(new PhoneNumber(123,"999-456"));
現在,要將其轉換爲XML,只需要簡單的調用XStream的toXML()
方法
String xml = xstream.toXML(person);
現在,爲了使 XStream 輸出的 XML 更簡潔,可以爲 XML 元素名的自定義類名創建別名。這是使用 XStream 所需的惟一映射類型,當然這是可選的。
xstream.alias("person",Person.class);
我們會發現XML變得更簡潔
2.4.將XML反序列化對象
首先,我們重寫Person
對象的toString()
@Override
public String toString() {
return "Person{" +
"firstname='" + firstname + ''' +
", lastname='" + lastname + ''' +
", phone=" + phone +
", fax=" + fax +
'}';
}
要重構一個對象,我們只需調用fromXML()
方法
XStream xstream = new XStream();
xstream.alias("person",Person.class);
//xml字符串
String xmldemo = "<?xml version="1.0" ?><person><firstname>Joe</firstname><lastname>milo</lastname><phone><code>123</code><number>1234-456</number></phone><fax><code>123</code><number>999-456</number></fax></person>";
Person o = (Person)xstream.fromXML(xmldemo);
System.out.println(o.toString());
關於更多關於Xstream的操作,大家可以閱讀:
https://www.cnblogs.com/jpfss/p/9836465.html
三.高級入門
在高級入門中,我們以支付寶生活號開發爲例,採用Xstream的註解開發來完成事件訂閱過程中的xml報文相關的操作
3.1 項目搭建
首先我們搭建項目springboot-xstream
,當然你可以在
https://gitee.com/milogenius/milogenius-springboot
找到源代碼,案例位於springboot-xstream
模塊下面。由於案例代碼太多,強烈建議大家下載源代碼案例自己跑一跑。
3.2 相關類解釋
3.3 和XStream相關的類
1.AlipayXmlMessage
package com.milo.xstream.xml;
import com.thoughtworks.xstream.annotations.XStreamAlias;
import com.thoughtworks.xstream.annotations.XStreamConverter;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import java.io.InputStream;
import java.io.Serializable;
import java.util.Map;
/**
* 支付寶生活號推送過來的xml消息
* @author milogenius
* @date 2020/4/4 15:29
*
*/
@Data
@Slf4j
@XStreamAlias("XML")
public class AlipayXmlMessage implements Serializable {
private static final long serialVersionUID = -3586245291677274914L;
/**
* 使用dom4j解析的存放所有xml屬性和值的map.
*/
private Map<String, Object> allFieldsMap;
///////////////////////
// 以下都是支付寶生活號推送過來的消息的xml的element所對應的屬性
///////////////////////
/**AppId*/
//AppId--->xml中的字段
//appId --->pojo中的字段
@XStreamAlias("AppId")
@XStreamConverter(value = XStreamCDataConverter.class)
private String appId;
/**用戶userid,用戶唯一標識*/
@XStreamAlias("FromAlipayUserId")
@XStreamConverter(value = XStreamCDataConverter.class)
private String fromAlipayUserId;
/**消息創建時間*/
@XStreamAlias("CreateTime")
private Long createTime;
/**消息類型*/
@XStreamAlias("MsgType")
@XStreamConverter(value = XStreamCDataConverter.class)
private String msgType;
/**事件類型*/
@XStreamAlias("EventType")
@XStreamConverter(value = XStreamCDataConverter.class)
private String eventType;
/**用戶從特定場景關注,帶的自定義參數值*/
@XStreamAlias("ActionParam")
@XStreamConverter(value = XStreamCDataConverter.class)
private String actionParam;
/**支付寶用戶信息*/
@XStreamAlias("UserInfo")
@XStreamConverter(value = XStreamCDataConverter.class)
private String userInfo;
/**消息id 用於消息去重*/
@XStreamAlias("MsgId")
private String msgId;
public static AlipayXmlMessage fromXml(String xml) {
//修改支付寶生活號變態的消息內容格式,方便解析
xml = xml.replace("<?xml version=\"1.0\" encoding=\"gbk\"?>", "");
final AlipayXmlMessage xmlMessage = XStreamTransformer.fromXml(AlipayXmlMessage.class, xml);
xmlMessage.setAllFieldsMap(XmlUtils.xml2Map(xml));
return xmlMessage;
}
public static AlipayXmlMessage fromXml(InputStream is) {
return XStreamTransformer.fromXml(AlipayXmlMessage.class, is);
}
}
2.AlipayXmlOutMessage
package com.milo.xstream.outxml;
import com.milo.xstream.builder.AckBuilder;
import com.milo.xstream.xml.XStreamCDataConverter;
import com.milo.xstream.xml.XStreamTransformer;
import com.thoughtworks.xstream.annotations.XStreamAlias;
import com.thoughtworks.xstream.annotations.XStreamConverter;
import lombok.Data;
import java.io.Serializable;
/**
* 響應XML
* @author milogenius
* @date 2020/4/4 11:57
*
*/
@XStreamAlias("xml")
@Data
public abstract class AlipayXmlOutMessage implements Serializable {
private static final long serialVersionUID = -381382011286216263L;
/**接受者userid*/
@XStreamAlias("ToUserId")
@XStreamConverter(value = XStreamCDataConverter.class)
protected String toUserId;
/**支付寶生活號appid*/
@XStreamAlias("AppId")
@XStreamConverter(value = XStreamCDataConverter.class)
protected String appId;
/**創建時間*/
@XStreamAlias("CreateTime")
protected Long createTime;
/**消息類型*/
@XStreamAlias("MsgType")
@XStreamConverter(value = XStreamCDataConverter.class)
protected String msgType;
@XStreamAlias("response")
protected Response response;
@XStreamAlias("sign")
protected String sign;
@XStreamAlias("sign_type")
protected String signType;
/**
* 獲得ack builder
* @return
*/
public static AckBuilder ACK() {
return new AckBuilder();
}
@SuppressWarnings("unchecked")
public String toXml() {
StringBuilder builder = new StringBuilder();
String xml = XStreamTransformer.toXml((Class<AlipayXmlOutMessage>) this.getClass(), this);
builder.append("<?xml version="1.0" encoding="gbk"?>n");
builder.append(xml);
return builder.toString();
}
}
3.XStreamCDataConverter
package com.milo.xstream.xml;
import com.thoughtworks.xstream.converters.basic.StringConverter;
/**
* 自定義轉換器
* @author milogenius
* @date 2020/4/4 10:56
*
*/
public class XStreamCDataConverter extends StringConverter {
@Override
public String toString(Object obj) {
return "<![CDATA[" + super.toString(obj) + "]]>";
}
}
相關注解說明
@XStreamAlias
用於定義XStream
類或字段別名的註釋
@XStreamConverter
用於聲明轉換器的註釋
3.4 測試
XmlDemoTest
package com.milo.xstream;
import com.milo.xstream.outxml.AlipayXmlOutMessage;
import com.milo.xstream.xml.AlipayXmlMessage;
/**
* @author milogenius
* @date 2020-04-04 11:49
*/
public class XmlDemoTest {
public static void main(String[] args) {
//xml --->pojo
String bizContent = "<XML>n" +
" <AppId><![CDATA[2014070100171523]]></AppId>n" +
" <FromUserId><![CDATA[20882837462837462837462837461234]]></FromUserId>n" +
" <FromAlipayUserId><![CDATA[2088283746283746]]></FromAlipayUserId>n" +
" <CreateTime><![CDATA[1405943673657]]></CreateTime>n" +
" <MsgType><![CDATA[event]]></MsgType>n" +
" <EventType><![CDATA[follow]]></EventType>n" +
" <ActionParam><![CDATA[{"scene":{"sceneId": "1234"}}]]></ActionParam>n" +
" <AgreementId><![CDATA[]]></AgreementId>n" +
" <AccountNo><![CDATA[]]></AccountNo>n" +
" <UserInfo><![CDATA[{"logon_id":"135****1009","user_name":"*iuxu527"}]]></UserInfo>n" +
"</XML>";
AlipayXmlMessage alipayXmlMessage = AlipayXmlMessage.fromXml(bizContent);
// System.out.println(alipayXmlMessage);
//pojo --->xml
AlipayXmlOutMessage mpXmlOutMessage = AlipayXmlOutMessage.ACK().toUserId("123456").appId("99999999").build();
String xml = mpXmlOutMessage.toXml();
System.out.println(xml);
}
}
3.5測試結果
3.5.1 xml ---->pojo
3.5.2 pojo --->xml
四.總結
通過上面的一些小案例,高質量編程視頻shangyepingtai.xin 我們學習Xstream的基本用法和註解用法,文章到此爲止,謝謝大家閱讀;