JAXB

Java Architecture for XML Binding ( JAXB ) 主要用于Java对象和XML之间的相关转换，开始是作为一个独立项目开发，后来被集成到JDK中（自Java 6）。

• JAXB Marshalling：将Java对象转换为XML
• JAXB Unmarshalling：将XML对象转换为Java Object

JAXB主要使用注释（annotations）来实现对象转换，比如，如果你需要将Java对象转换为XML，我们需要创建Marshaller对象，如果需要将XML转换为Java对象，则需要创建Unmarshaller对象。

在JAXB中，你需要先创建JAXBContext对象提供了获取marshaller和unmarshall对象的方法

一些常用的JAXB注释，官网中有更多JAXB中使用的注释。JAXB Official Site

• @XmlRootElement
• @XmlType
• @XMLTransient
• @XmlAttibute

• @XmlElement（name=“abc”）

  XML To Java Object

<?xml version="1.0" encoding="UTF-8"?>
<root>
<requests>
<request id="123">
<url>http://www.baidu.com</url>
<cookie>username=test;logintime=20170202131415789;</cookie>
<encoding>utf-8</encoding>
</request>
</requests>
</root>

Java Bean

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;

public class Request {
    private String url;
    private String cookie;
    private String encoding;
    private int id;
    public int getId() {
        return id;
    }
    @XmlAttribute
    public void setId(int id) {
        this.id = id;
    }
    public String getUrl() {
        return url;
    }
    @XmlElement
    public void setUrl(String url) {
        this.url = url;
    }
    public String getCookie() {
        return cookie;
    }
    @XmlElement
    public void setCookie(String cookie) {
        this.cookie = cookie;
    }
    public String getEncoding() {
        return encoding;
    }
    @XmlElement
    public void setEncoding(String encoding) {
        this.encoding = encoding;
    }

    public String toString(){
        return "id = "+id+",url = " + url+",cookie = " +cookie+",encoding = " + encoding;
    }
}

import java.util.ArrayList;

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlElementWrapper;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name = "root")
public class Requests {
    private ArrayList<Request> requests;


    public void addRequest(Request request){
        if(requests == null){
            requests = new ArrayList<Request>();
        }
        requests.add(request);
    }


    public ArrayList<Request> getRequests() {
        return requests;
    }

    @XmlElementWrapper(name="requests")
    @XmlElement(name="request")
    public void setRequests(ArrayList<Request> requests) {
        this.requests = requests;
    }

}

XML To Bean

@SuppressWarnings("unchecked")
    public static <T> T xmlToBean(Class<T> bean,File file){
        T s = null;
        try{
            JAXBContext context = JAXBContext.newInstance(bean);
            Unmarshaller unmarshaller = context.createUnmarshaller();
            s = (T)unmarshaller.unmarshal(file);
        }catch(Exception e){
            e.printStackTrace();
        }
        return s;
    }

Java Object To XML

import javax.xml.bind.annotation.XmlElement;

public class Result {
    private String response;
    private String url;
    private String status;

    public String getResponse() {
        return response;
    }

    @XmlElement
    public void setResponse(String response) {
        this.response = response;
    }

    public String getUrl() {
        return url;
    }

    @XmlElement
    public void setUrl(String url) {
        this.url = url;
    }

    public String getStatus() {
        return status;
    }

    @XmlElement
    public void setStatus(String status) {
        this.status = status;
    }

    public String toString() {
        return "status = " + status + ",url = " + url + ",response = " + response;
    }
}

import java.util.List;

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlElementWrapper;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="root")
public class Results {
    private List<Result> results;

    public List<Result> getResults() {
        return results;
    }
    @XmlElementWrapper(name = "results")
    @XmlElement(name="result")
    public void setResults(List<Result> results) {
        this.results = results;
    }
}

Bean To XML

public static <T> String beanToXml(T bean){
        String xmlStr = null;
        StringWriter writer = null;
        try{
            JAXBContext context = JAXBContext.newInstance(bean.getClass());
            Marshaller marshaller = context.createMarshaller();
            writer = new StringWriter();
            marshaller.marshal(bean,writer);
            xmlStr = writer.toString();
        }catch(Exception e){
            e.printStackTrace();
        }       
        return xmlStr;
    }
    public static <T> void beanToXml(String fileName,T bean){
        try{
            File file = new File(fileName);
            JAXBContext context = JAXBContext.newInstance(bean.getClass());
            Marshaller marshaller = context.createMarshaller();
            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT,true);
            marshaller.marshal(bean,file);
            marshaller.marshal(bean,System.out);
        }catch(Exception e){
            e.printStackTrace();
        }
    }

result.xml

这里写链接内容

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!