jaxb實現xml與bean的相互轉化
阿新 • • 發佈：2018-12-24
jaxb使用說明
這裡邊有提到MessageFormat，可以瞭解下。下邊還有一個其他部落格粘過來的幾行程式碼，記錄一下。
這裡以《書》為例，寫一個完整的測試程式碼，xml包含了各種元素和集合。
test.xml
<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<book id="1234567890" name="尋醫不如自醫">
<author>陳金柱</author>
<press>金城出版社</press>
<main_info>
<chapters_num>5</chapters_num>
<editor>王景濤</editor>
<pub_time>2017-01-01</pub_time>
</main_info>
<chapters>
<chapter>
<num>1</num>
<name>你所不知道的事</name>
</chapter>
<chapter>
<num>2</num>
<name>人體中有哪些重要的部分</name>
</chapter>
<chapter>
<num>3</num>
<name>中醫健康基礎知識</name>
</chapter>
</chapters>
</book>實體類：
import java.util.List;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlElementWrapper;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType; /** * 書 * 不指定順序的時候是按英文字母排序的 * propOrder指定順序，裡邊填的是屬性的名，不是註解裡的name * 如果指定順序的話，需要把所有屬性都寫裡邊，不然會報錯 * @author changxinzhi * */ @XmlRootElement(name = "book") @XmlType(propOrder={"id","name","author","press","mainInfo","chapters"}) public class Book { private String id;//圖書ID private String name;//圖書名稱 private String author;//作者 private String press;//出版社 private MainInfo mainInfo;//重要資訊 private List<Chapter> chapters;//章節資訊 @XmlAttribute(name = "id") public String getId() { return id; } public void setId(String id) { this.id = id; } @XmlAttribute(name = "name") public String getName() { return name; } public void setName(String name) { this.name = name; } @XmlElement(name = "author") public String getAuthor() { return author; } public void setAuthor(String author) { this.author = author; } @XmlElement(name = "press") public String getPress() { return press; } public void setPress(String press) { this.press = press; } @XmlElement(name = "main_info") public MainInfo getMainInfo() { return mainInfo; } public void setMainInfo(MainInfo mainInfo) { this.mainInfo = mainInfo; } @XmlElementWrapper(name = "chapters") @XmlElement(name = "chapter") public List<Chapter> getChapters() { return chapters; } public void setChapters(List<Chapter> chapters) { this.chapters = chapters; } }
import javax.xml.bind.annotation.XmlRootElement;
/**
* 書的重要資訊
* @author cxz
*/
@XmlRootElement(name = "main_info")
public class MainInfo {
private String editor;//責任編輯
private String pub_time;
private String chapters_num; public String getEditor() { return editor; } public void setEditor(String editor) { this.editor = editor; } public String getPub_time() { return pub_time; } public void setPub_time(String pub_time) { this.pub_time = pub_time; } public String getChapters_num() { return chapters_num; } public void setChapters_num(String chapters_num) { this.chapters_num = chapters_num; } }
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
/**
* 章節資訊
* @author cxz
*/
@XmlRootElement(name="chapter")
@XmlType(propOrder={"num","name"})
public class Chapter { private String num; private String name; public String getNum() { return num; } public void setNum(String num) { this.num = num; } public String getName() { return name; } public void setName(String name) { this.name = name; } }
工具類
import java.io.StringReader;
import java.io.StringWriter;
import java.text.MessageFormat;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller; import javax.xml.bind.Unmarshaller; /** * json使用alibaba.fastjson * @author cxz * Jaxb2.0 處理Xml與Object轉換 */ public class JaxbObjectAndXmlUtil { /** * 此處使用了Stringreader，其實Unmarshaller介面還支援 * File，InputStream，URL，StringBuffer，org.w3c.dom.Node等反序列化 * API連線 * http://tool.oschina.net/uploads/apidocs/jdk-zh/javax/xml/bind/Unmarshaller.html * @param xmlStr 字串 * @param c 物件Class型別 * @return 物件例項 */ @SuppressWarnings({ "unchecked", "finally" }) public static <T> T xml2Object(String xmlStr,Class<T> c){ try{ JAXBContext context = JAXBContext.newInstance(c); Unmarshaller unmarshaller = context.createUnmarshaller(); T t = (T) unmarshaller.unmarshal(new StringReader(xmlStr)); return t; } catch (JAXBException e) { e.printStackTrace(); return null; } } /** * 可變引數 * config裡使用佔位符 {0} {1} {2}，單引號要使用兩個
* MessageFormat使用連結 * @param config * @param c * @param arguments * @return */ @SuppressWarnings("unchecked") public static <T> T xml2Object(String config,Class<T> c,Object... arguments){ try{ if (arguments.length > 0) { config = MessageFormat.format(config, arguments); } JAXBContext context = JAXBContext.newInstance(c); Unmarshaller unmarshaller = context.createUnmarshaller(); T t = (T) unmarshaller.unmarshal(new StringReader(config)); return t; } catch (JAXBException e) { e.printStackTrace(); return null; } } /** * @param object 物件 * @return 返回xmlStr */ public static String object2Xml(Object object){ try{ StringWriter writer = new StringWriter(); JAXBContext context = JAXBContext.newInstance(object.getClass()); Marshaller marshal = context.createMarshaller(); marshal.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); // 格式化輸出 marshal.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");// 編碼格式,預設為utf-8 marshal.setProperty(Marshaller.JAXB_FRAGMENT, false);// 是否省略xml頭資訊 marshal.setProperty("jaxb.encoding", "utf-8"); marshal.marshal(object,writer); return new String(writer.getBuffer()); }catch(Exception e){ e.printStackTrace(); return null; } } }
測試類
import java.util.ArrayList;
import java.util.List;
import com.alibaba.fastjson.JSON;
public class test {
/**
* 測試方法
* @param args
*/
public static void main(String[] args){
//建立內容
MainInfo mainInfo = new MainInfo(); mainInfo.setEditor("王景濤"); mainInfo.setPub_time("2017-01-01"); mainInfo.setChapters_num("5"); Chapter chapter1 = new Chapter(); chapter1.setNum("1"); chapter1.setName("你所不知道的事"); Chapter chapter2 = new Chapter(); chapter2.setNum("2"); chapter2.setName("人體中有哪些重要的部分"); Chapter chapter3 = new Chapter(); chapter3.setNum("3"); chapter3.setName("中醫健康基礎知識"); Book book = new Book(); List<Chapter> chapters = new ArrayList<Chapter>(); chapters.add(chapter1); chapters.add(chapter2); chapters.add(chapter3); book.setChapters(chapters); book.setMainInfo(mainInfo); book.setId("1234567890"); book.setName("尋醫不如自醫"); book.setAuthor("陳金柱"); book.setPress("金城出版社"); String xmlStr = JaxbObjectAndXmlUtil.object2Xml(book);//構造報文 XML 格式的字串 System.out.println("物件轉xml報文： \n"+xmlStr); Book book2 = JaxbObjectAndXmlUtil.xml2Object(xmlStr, Book.class); System.out.println("報文轉xml轉： \n"+JSON.toJSONString(book2)); } }
到這裡已寫完。
粘過來的幾行程式碼，歡迎留言討論。
import java.io.StringReader; import java.io.StringWriter; import java.util.Collection; 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 org.apache.commons.lang.StringUtils; /** * 使用Jaxb2.0實現XML<->Java Object的Binder. * StringUtils依賴commons-long包 * 特別支援Root物件是List的情形.---??? ‘xml規範就是有且只有一個根元素’--不甚理解這裡的做法 * @author */ public class JaxbUtil { // 多執行緒安全的Context. private JAXBContext jaxbContext; /** * @param types 所有需要序列化的Root物件的型別. */ 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, 特別支援對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, 支援大小寫敏感或不敏感. */ @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); } } /** * 建立Marshaller, 設定encoding(可為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); } } /** * 建立UnMarshaller. */ public Unmarshaller createUnmarshaller() { try { return jaxbContext.createUnmarshaller(); } catch (JAXBException e) { throw new RuntimeException(e); } } /** * 封裝Root Element 是 Collection的情況.
* xmlAnyType查到的東西不多，不太懂這個。 */ public static class CollectionWrapper { @SuppressWarnings("unchecked") @XmlAnyElement protected Collection collection; } }
測試方法片段
//寫不寫CollectionWrapper.class有什麼區別，都可以正常執行 //將java物件轉換為XML字串 JaxbUtil requestBinder = new JaxbUtil(Hotel.class,CollectionWrapper.class); String retXml = requestBinder.toXml(hotel, "utf-8"); System.out.println("xml:"+retXml); //將xml字串轉換為java物件 JaxbUtil resultBinder = new JaxbUtil(Hotel.class,CollectionWrapper.class); Hotel hotelObj = resultBinder.fromXml(retXml);