java - JAXB:JAXB 的问题

Question

我们希望使用 JAX-RS 和 JAXB 实现 RESTful Web 服务。我们有一个使用 xml 的 PUT 方法，如下所示:

<mailAccount>
    <id>-1</id>
    <name>test</name>
    <mailaddress><a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="126677616652757f6a3c7677" rel="noreferrer noopener nofollow">[email protected]</a></mailaddress>
    <password>1234</password>
    <servertype>IMAP</servertype>
    <host>hallo</host>
    <port>5678</port>
    <encryption>SSL/TLS</encryption>
    <authentication>true</authentication>
    <interval>12</interval>
</mailAccount>

我们还有一个映射到 xml 的 MailAccount.class。

@XmlRootElement
public class MailAccount {

private String name;
private String mailaddress;
private String password;
private String servertype;
private String host;
private int port;
private String encryption;
private boolean authentication;
private int interval;
private int id;

getter + setter...
}

PUT 方法如下所示:

@PUT()
@Path("/addMailAccount")
@Consumes(MediaType.APPLICATION_XML)
@Produces(MediaType.TEXT_HTML)
public Response addMailAccount(JAXBElement<MailAccount> mail) throws Exception{
    MailAccount mailAccounts = mail.getValue();

    StringWriter sw = new StringWriter();

    JAXBContext jaxbContext = JAXBContext.newInstance(MailAccount.class);
    Marshaller jaxbMarshaller = jaxbContext.createMarshaller();

    jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

    jaxbMarshaller.marshal(mailAccounts, sw);

    String xmlConsume = sw.toString();

    Source source = new StreamSource(new StringReader(xmlConsume));

    SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
    Schema schema = sf.newSchema(MailAccountService.class.getResource("/emailAddresses.xsd"));

    Validator validator = schema.newValidator();

    //validator.validate(source);

    return Response.status(200).entity(xmlConsume +"..."+ mailAccounts.getMailadress()).build();
}

我们的目标是编码 JAXB 元素以根据 XML 模式对其进行验证。但问题在于编码:首先，元素的顺序不正确。使用 propOrder 标签每次都会导致内部服务器错误。

第二个问题是元素“mailaddress”为空。它不是编码，当我将其放入此方法的响应中时，该值为 null。

以下是 PUT 方法返回的内容:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<mailAccount>
    <authentication>true</authentication>
    <encryption>SSL/TLS</encryption>
    <host>hallo</host>
    <id>-1</id>
    <interval>12</interval>
    <name>test</name>
    <password>1234</password>
    <port>5678</port>
    <servertype>IMAP</servertype>
</mailAccount>
...null

Answer 1

以下几项应该会有所帮助:

propOrder

下面是将 propOrder 应用于您的类的示例。请务必记住，您需要在 propOrder 中包含映射到 XML 元素的所有映射字段/属性。

import javax.xml.bind.annotation.*;

@XmlRootElement
@XmlType(propOrder={"id", "name", "mailaddress", "password", "servertype", "host", "port", "encryption", "authentication", "interval"})
@XmlAccessorType(XmlAccessType.FIELD)
public class MailAccount {

    private String name;
    private String mailaddress;
    private String password;
    private String servertype;
    private String host;
    private int port;
    private String encryption;
    private boolean authentication;
    private int interval;
    private int id;

}

将架构验证作为编码(marshal)操作的一部分

下面是一个独立的示例，演示了如何利用架构验证作为编码操作的一部分，而不是将其作为单独的操作进行(请参阅:http://blog.bdoughan.com/2010/12/jaxb-and-marshalunmarshal-schema.html)。

import java.io.File;
import javax.xml.XMLConstants;
import javax.xml.bind.*;
import javax.xml.validation.*;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(MailAccount.class);

        Unmarshaller unmarshaller = jc.createUnmarshaller();
        File xml = new File("src/forum20699078/input.xml");
        MailAccount mailAccount = (MailAccount) unmarshaller.unmarshal(xml);

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

        SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
        Schema schema = sf.newSchema(MailAccountService.class.getResource("/emailAddresses.xsd"));
        marshaller.setSchema(schema);

        marshaller.marshal(mailAccount, System.out);
    }

}