java socket报文通信(三)java对象和xml格式文件的相互转换

前两节讲了socket服务端,客户端的建立以及报文的封装。今天就来讲一下java对象和xml格式文件的相互转换。

上一节中我们列举了一个报文格式,其实我们可以理解为其实就是一个字符串。但是我们不可能每次都去写字符串啊,这样的话肯定要疯。既然是面向对象的编程,肯定会有好的办法来解决这个问题。我们使用JAXBContext这个工具。

package cn.com.egj.entity.shortcutTransfer.test;



import java.io.BufferedReader;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.StringReader;

import java.net.URLEncoder;



import javax.xml.bind.JAXBContext;

import javax.xml.bind.JAXBException;

import javax.xml.bind.Marshaller;

import javax.xml.bind.Unmarshaller;

import javax.xml.bind.annotation.XmlRootElement;

import javax.xml.stream.XMLOutputFactory;

import javax.xml.stream.XMLStreamWriter;



/**

 * Jaxb2工具类

 */

@XmlRootElement

public class JaxbUtil {



    /**

     * JavaBean转换成xml

     * 

     * @param obj

     * @param encoding

     * @return

     */

    public static String convertToXml(Object obj) {



        try {

            JAXBContext context = JAXBContext.newInstance(obj.getClass());

            Marshaller marshaller = context.createMarshaller();



            marshaller.setProperty(Marshaller.JAXB_ENCODING, "GBK");

            marshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);



            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            //注意jdk版本

            XMLOutputFactory xmlOutputFactory = XMLOutputFactory.newInstance();

            XMLStreamWriter xmlStreamWriter = xmlOutputFactory

                    .createXMLStreamWriter(baos, (String) marshaller

                            .getProperty(Marshaller.JAXB_ENCODING));

            xmlStreamWriter.writeStartDocument(

                    (String) marshaller.getProperty(Marshaller.JAXB_ENCODING),

                    "1.0");

            marshaller.marshal(obj, xmlStreamWriter);

            xmlStreamWriter.writeEndDocument();

            xmlStreamWriter.close();

            return new String(baos.toString("GBK"));

            

        } catch (Exception e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return null;



    }



    /**

     * xml转换成JavaBean

     * 

     * @param xml

     * @param c

     * @return

     */

    @SuppressWarnings("unchecked")

    public static <T> T converyToJavaBean(String xml, Class<T> c) {

        T t = null;

        try {

            JAXBContext context = JAXBContext.newInstance(c);

            Unmarshaller unmarshaller = context.createUnmarshaller();

            t = (T) unmarshaller.unmarshal(new StringReader(xml));

        } catch (Exception e) {

            e.printStackTrace();

        }



        return t;

    }



}

以上两个方法可以将java对象可xml文件相互转换。

接下来我们看看怎么使用。

1)首先我们要建立需要转换的类:

import javax.xml.bind.annotation.XmlAccessType;

import javax.xml.bind.annotation.XmlAccessorType;

import javax.xml.bind.annotation.XmlElement;

import javax.xml.bind.annotation.XmlRootElement;

import javax.xml.bind.annotation.XmlType;



@XmlAccessorType(XmlAccessType.FIELD)//表示使用这个类中的 private 非静态字段作为 XML 的序列化的属性或者元素,对应属性要使用get、set方法。

@XmlRootElement(name="ROOT")

@XmlType(propOrder={"code","name","age"})//xml格式数据的显示的顺序名字要和定义变量的一样,而不是@XmlElement中的name

public class MySocket {

    @XmlElement(name="Code",required=true)//定义xml中显示的数据

    private  String code;

    @XmlElement(name="Name",required=true)

    private String name;

    @XmlElement(name="Age",required=true)

    private String age;

    public String getCode() {

        return code;

    }

    public String getName() {

        return name;

    }

    public String getAge() {

        return age;

    }

    public void setCode(String code) {

        this.code = code;

    }

    public void setName(String name) {

        this.name = name;

    }

    public void setAge(String age) {

        this.age = age;

    }

    

    public String toString(){

        return this.name+","+this.age+","+this.code;

    }

}

2)建立测试类:

public class Test {

    public static void main(String[] args) {

        objectToXml();

    }    

    public static  void objectToXml(){

        MySocket mySocket = new MySocket();

        mySocket.setName("张三");

        mySocket.setCode("00012");

        mySocket.setAge("25");

        String xml = JaxbUtil.convertToXml(mySocket);

        System.out.println(xml);

    }    

}

运行测试类,我们将看到控制台输出:<?xml version="1.0" encoding="GBK"?><ROOT><Code>00012</Code><Age>25</Age></ROOT>

对于Object转xml,我们建立测试方法:

 

public static void xmlToObjetct(){

        String xml = "<?xml version=\"1.0\" encoding=\"GBK\"?><ROOT><Code>00011</Code><Name>李四</Name><Age>26</Age></ROOT>";

        MySocket mySocket= JaxbUtil.converyToJavaBean(xml, MySocket.class);

        System.out.println(mySocket.toString());

    }

 

 运行测试类,我们将看到控制台输出:李四,26,00011

3)有时候我们的java对象中会存在集合,这时我们像如下这么做:

  3.1)首先我们建立袋集合的对象:

 

@XmlAccessorType(XmlAccessType.FIELD)

@XmlRootElement(name="ROOT")

@XmlType(propOrder={"name","age","books"})

public class ListSocket {



    @XmlElement(name="Name",required=true)

    private String name;

    @XmlElement(name="Age",required=true)

    private String age;

    @XmlElementWrapper(name="ROWS")//@XmlElementWrapper注解表示生成一个包装 XML 表示形式的包装器元素。 此元素主要用于生成一个包装集合的包装器 XML 元素

    @XmlElement(name="LIST",required=true)

    private List<Book> books;

    public String getName() {

        return name;

    }

    public String getAge() {

        return age;

    }

    public List<Book> getBooks() {

        return books;

    }

    public void setName(String name) {

        this.name = name;

    }

    public void setAge(String age) {

        this.age = age;

    }

    public void setBooks(List<Book> books) {

        this.books = books;

    }

    

    public String toString(){

        String result = "";

        result=this.age+","+this.name+",集合的数据:";

        for (Book book:books) {

            result+=book.getAuthor()+book.getTime()+book.getBookName();

        }

        return result;

    }

}

 

@XmlAccessorType(XmlAccessType.FIELD)

@XmlType(propOrder={"bookName","time","author"})

public class Book {

    @XmlElement(name="BookName")

    private String bookName;

    @XmlElement(name="Time")

    private String time;

    @XmlElement(name="Author")

    private String author;

    public String getBookName() {

        return bookName;

    }

    public String getTime() {

        return time;

    }

    public String getAuthor() {

        return author;

    }

    public void setBookName(String bookName) {

        this.bookName = bookName;

    }

    public void setTime(String time) {

        this.time = time;

    }

    public void setAuthor(String author) {

        this.author = author;

    }

}

 

 3.2)建立测试类:

 

public class ListSocketTest {

    public static void main(String[] args) {

        objectToXml();

        xmlToObject();

    }

    

    public static void objectToXml(){

        ListSocket listSocket = new ListSocket();

        listSocket.setName("张三");

        listSocket.setAge("26");

        List<Book> books = new ArrayList<Book>();

        Book book1 = new Book();

        book1.setAuthor("作者1");

        book1.setTime("2014-12-28");

        book1.setBookName("How to use JAXB");

        Book book2= new Book();

        book2.setAuthor("作者2");

        book2.setTime("2014-06-06");

        book2.setBookName("How to use SOCKET");

        books.add(book1);

        books.add(book2);

        listSocket.setBooks(books);

        String xml = JaxbUtil.convertToXml(listSocket);

        System.out.println(xml);

    }

    

    public static void xmlToObject(){

        String xml = "<?xml version=\"1.0\" encoding=\"GBK\"?><ROOT><Name>张三</Name><Age>26</Age><ROWS><LIST>"
+"<BookName>How to use JAXB</BookName><Time>2014-12-28</Time><Author>作者1</Author>"
+"</LIST><LIST><BookName>How to use SOCKET</BookName><Time>2014-06-06</Time><Author>作者2</Author></LIST></ROWS></ROOT>"; ListSocket listSocket = JaxbUtil.converyToJavaBean(xml, ListSocket.class); System.out.println(listSocket); }

 

 运行主函数,我们可以看见转换后的xml对象和类对象。使用就是这么的简单^_^!!!

 

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