WebService学习笔记(三) - JAXB与Stax

处理soap消息离不开xml处理

一 JAXB

用于完成xml与java对象的转换。java对象定义：

java代码：

import javax.xml.bind.annotation.XmlRootElement;@XmlRootElementpublic class Student {    private int id;    private String name;    private int age;    private Classroom classroom;}

@XmlRootElement不能缺少

java代码：

public class Classroom {    private int id;    private String name;    private int grade;}

1.1 java->xml

java代码：

JAXBContext ctx = JAXBContext.newInstance(Student.class);Marshaller marshaller = ctx.createMarshaller();Student stu = new Student(1,"张三",21,new Classroom(1,"10计算机应用技术",2010));marshaller.marshal(stu, System.out);

1.2 xml->java

java代码：

String xml = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?><student><age>21</age><classroom><grade>2010</grade><id>1</id><name>10计算机应用技术</name></classroom><id>1</id><name>张三</name></student>";JAXBContext ctx = JAXBContext.newInstance(Student.class);Unmarshaller um = ctx.createUnmarshaller();Student stu = (Student)um.unmarshal(new StringReader(xml));

二 Stax

待处理的的xml文件

xml代码：

<?xml version="1.0" encoding="UTF-8"?><bookstore><book category="COOKING">  <title lang="en">Everyday Italian</title>  <author>Giada De Laurentiis</author>  <year>2005</year>  <price>30.00</price></book><book category="CHILDREN">  <title lang="en">Harry Potter</title>  <author>J K. Rowling</author>  <year>2005</year>  <price>29.99</price></book><book category="WEB">  <title lang="en">XQuery Kick Start</title>  <author>James McGovern</author>  <author>Per Bothner</author>  <author>Kurt Cagle</author>  <author>James Linn</author>  <author>Vaidyanathan Nagarajan</author>  <year>2003</year>  <price>49.99</price></book><book category="WEB">  <title lang="en">Learning XML</title>  <author>Erik T. Ray</author>  <year>2003</year>  <price>39.95</price></book></bookstore>

2.1 基于光标

java代码：遍历文档

XMLInputFactory factory = XMLInputFactory.newInstance();InputStream is = this.class.getClassLoader().getResourceAsStream("books.xml");XMLStreamReader reader = factory.createXMLStreamReader(is);while(reader.hasNext()) {    int type = reader.next();    //判断节点类型是否是开始或者结束或者文本节点,之后根据情况及进行处理    if(type==XMLStreamConstants.START_ELEMENT) {        System.out.println(reader.getName());    } else if(type==XMLStreamConstants.CHARACTERS) {        System.out.println(reader.getText().trim());    } else if(type==XMLStreamConstants.END_ELEMENT) {        System.out.println("/"+reader.getName());    }<br>}

java代码：输出book的属性

XMLInputFactory factory = XMLInputFactory.newInstance();InputStream is =  TestStax.class.getClassLoader().getResourceAsStream("books.xml");XMLStreamReader reader = factory.createXMLStreamReader(is);while(reader.hasNext()) {        int type = reader.next();        if(type==XMLStreamConstants.START_ELEMENT) {            String name = reader.getName().toString();            if(name.equals("book")) {                System.out.println(reader.getAttributeName(0)+":"+reader.getAttributeValue(0));            }        }}

java代码：输出title和price

XMLInputFactory factory = XMLInputFactory.newInstance();InputStream is = TestStax.class.getClassLoader().getResourceAsStream("books.xml");XMLStreamReader reader = factory.createXMLStreamReader(is);while(reader.hasNext()) {    int type = reader.next();    if(type==XMLStreamConstants.START_ELEMENT) {        String name = reader.getName().toString();        if(name.equals("title")) {            System.out.print(reader.getElementText()+":");        }        if(name.equals("price")) {            System.out.print(reader.getElementText()+"\n");        }    }}

2.2 基于迭代模型

java代码：

XMLInputFactory factory = XMLInputFactory.newInstance();InputStream is =  TestStax.class.getClassLoader().getResourceAsStream("books.xml");//基于迭代模型的操作方<br> XMLEventReader reader = factory.createXMLEventReader(is);while(reader.hasNext()) {    //通过XMLEvent来获取是否是某种节点类型    XMLEvent event = reader.nextEvent();    if(event.isStartElement()) {        //通过event.asxxx转换节点        String name = event.asStartElement().getName().toString();        if(name.equals("title")) {            System.out.print(reader.getElementText()+":");        }        if(name.equals("price")) {            System.out.print(reader.getElementText()+"\n");        }    }}

2.3 基于Filter的过滤方式

java代码：

XMLInputFactory factory = XMLInputFactory.newInstance();InputStream is =  TestStax.class.getClassLoader().getResourceAsStream("books.xml");//基于Filter的过滤方式，可以有效的过滤掉不用进行操作的节点，效率会高一些XMLEventReader reader = factory.createFilteredReader(factory.createXMLEventReader(is),new EventFilter() {    @Override    public boolean accept(XMLEvent event) {        //返回true表示会显示，返回false表示不显示        if(event.isStartElement()) {            String name = event.asStartElement().getName().toString();            if(name.equals("title")||name.equals("price"))                return true;        }        return false;    }});while(reader.hasNext()) {    //通过XMLEvent来获取是否是某种节点类型    XMLEvent event = reader.nextEvent();    if(event.isStartElement()) {        //通过event.asxxx转换节点        String name = event.asStartElement().getName().toString();        if(name.equals("title")) {            System.out.print(reader.getElementText()+":");        }        if(name.equals("price")) {            System.out.print(reader.getElementText()+"\n");        }    }}

2.4 基于XPATH的处理

java代码：

InputStream is = TestStax.class.getClassLoader().getResourceAsStream("books.xml");//创建文档处理对象DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();//通过DocumentBuilder创建doc的文档对象Document doc = db.parse(is);//创建XPathXPath xpath = XPathFactory.newInstance().newXPath();//第一个参数就是xpath,第二参数就是文档NodeList list = (NodeList)xpath.evaluate("//book[@category='WEB']", doc,XPathConstants.NODESET);for(int i=0;i<list.getLength();i++) {    //遍历输出相应的结果    Element e = (Element)list.item(i);    System.out.println(e.getElementsByTagName("title").item(0).getTextContent());}

2.5 写文档和修改文档

java代码：

XMLStreamWriter xsw = XMLOutputFactory.newInstance().createXMLStreamWriter(System.out);xsw.writeStartDocument("UTF-8","1.0");xsw.writeEndDocument();String ns = "http://11:dd";xsw.writeStartElement("nsadfsadf","person",ns);xsw.writeStartElement(ns,"id");xsw.writeCharacters("1");xsw.writeEndElement();xsw.writeEndElement();xsw.flush();xsw.close();

java代码：

InputStream is = TestStax.class.getClassLoader().getResourceAsStream("books.xml");//创建文档处理对象DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();//通过DocumentBuilder创建doc的文档对象Document doc = db.parse(is);//创建XPathXPath xpath = XPathFactory.newInstance().newXPath();Transformer tran = TransformerFactory.newInstance().newTransformer();tran.setOutputProperty(OutputKeys.ENCODING,"UTF-8");tran.setOutputProperty(OutputKeys.INDENT, "yes");//第一个参数就是xpath,第二参数就是文档NodeList list = (NodeList)xpath.evaluate("//book[title='Learning XML']", doc,XPathConstants.NODESET);//获取price节点Element be = (Element)list.item(0);Element e = (Element)(be.getElementsByTagName("price").item(0));e.setTextContent("333.9");Result result = new StreamResult(System.out);//通过tranformer修改节点tran.transform(new DOMSource(doc), result);