根据XML生成实体类
因为对接系统的XML所需映射的实体类有几十个，自己来处理不太现实，于是一直找寻找这样的工具，终于让我发现了jaxb2-maven-plugin：
http://www.mojohaus.org/jaxb2-maven-plugin/Documentation/v2.2/
一键生成，使用也比较方便，但是需要在maven环境下，下面将介绍如果使用
在maven工程下的pom.xml导入：
<plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>jaxb2-maven-plugin</artifactId> <version>2.5.0</version> <executions> <execution> <id>id1</id> <phase>generate-sources</phase> <goals> <goal>xjc</goal> </goals> <configuration> <!-- XSD源文件 --> <sources> <source>src/main/xsd</source> </sources> <!-- 源码输出目录 --> <outputDirectory>target/generated-sources/jaxb</outputDirectory> <!-- 指定文件生产 --> <!--<schemaFiles>client_centric_data.xsd</schemaFiles>--> <packageName>com.zgz.adsr</packageName> </configuration> </execution> </executions> <!--<configuration>--> <!--<!– The package of your generated sources –>--> <!--<packageName>com.zgz</packageName>--> <!--</configuration>--> </plugin>
然后，在工程中是用mvn clean install就会生成源码了。
如果有多个XSD文件，可以不指定packageName，会自动分类，如果指定了，就所有实体类都在一起了，挺不方便的。可能是不清楚怎么设置，有清楚怎么设置的，麻烦评论让我学习一下。
下面说说，映射父节点的东东，因为请求的XML父节点要设置前缀以及各种东东的，例如下图：
可在生成的package-info.java文件中添加注解：
@javax.xml.bind.annotation.XmlSchema(
// 注意这里，下面的XmlNs匹配了，就显示ie前缀 namespace = "http://www.shkf.com/rootelement", //子节点的设置 //elementFormDefault = javax.xml.bind.annotation.XmlNsForm.QUALIFIED, xmlns={ @XmlNs(prefix="ie", namespaceURI="http://www.xxx.com/rootelement"), @XmlNs(prefix="ie1", namespaceURI="http://www.xxx.com/subaccount"), @XmlNs(prefix="ie2", namespaceURI="http://www.xxx.com/ccd"), @XmlNs(prefix="simple", namespaceURI="http://www.xxx.com/simple"), @XmlNs(prefix="tcl", namespaceURI="http://www.xxx.com/tcl"), @XmlNs(prefix="xsi", namespaceURI="http://www.w3.org/2001/XMLSchema-instance")} )
但是schemaLocation的设置就在请求实体转换为XML的时候做设置：
marshaller.setProperty(Marshaller.JAXB_SCHEMA_LOCATION, "http://www.xxx.com/rootelement root_elements.xsd ");
或者在父节点实体类加个属性值：
@XmlAttribute(name ="xsi:schemaLocation")
public String schemaLocation="http://www.xxx.com/rootelement root_elements.xsd ";
还有一种方式设置前缀，继承NamespacePrefixMapper，但跟着上面的属性设置，好像会有点问题，具体还没怎么研究。
使用这方式需要引用依赖，不然会报错。
<dependency>
<groupId>com.sun.xml.bind</groupId>
<artifactId>jaxb-impl</artifactId>
<version>2.2.4-1</version>
</dependency>
如要去掉standalone，可参考：
https://stackoverflow.com/questions/14152523/remove-standalone-yes-from-jaxb-generated-xml
https://blog.****.net/weixin_39964562/article/details/79072277
import java.io.*; import javax.xml.bind.*; import javax.xml.bind.annotation.XmlRootElement; import javax.xml.stream.*; @XmlRootElement public class Login { private JAXBContext jaxbContext; private XMLOutputFactory xmlOutputFactory; public Login() { try { jaxbContext = JAXBContext.newInstance(Login.class); xmlOutputFactory = XMLOutputFactory.newFactory(); } catch(Exception e) { e.printStackTrace(); } } public static void main(String[] args) { Login demo = new Login(); System.out.println(demo.getMessage()); } public final String getMessage() { try { Marshaller jaxbMarshaller = jaxbContext.createMarshaller(); jaxbMarshaller.setProperty("jaxb.encoding", "ISO-8859-1"); jaxbMarshaller.setProperty(Marshaller.JAXB_FRAGMENT, true); ByteArrayOutputStream baos = new ByteArrayOutputStream(); XMLStreamWriter xmlStreamWriter = xmlOutputFactory.createXMLStreamWriter(baos, (String) jaxbMarshaller.getProperty(Marshaller.JAXB_ENCODING)); xmlStreamWriter.writeStartDocument((String) jaxbMarshaller.getProperty(Marshaller.JAXB_ENCODING), "1.0"); jaxbMarshaller.marshal(this, xmlStreamWriter); xmlStreamWriter.writeEndDocument(); xmlStreamWriter.close(); return new String(baos.toByteArray()); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; } }
JaxbUtil类：
package xxxx.util; import com.sun.xml.bind.marshaller.NamespacePrefixMapper; //import com.sun.xml.internal.bind.marshaller.NamespacePrefixMapper; import org.apache.commons.lang.StringUtils; import org.xml.sax.SAXException; import org.xml.sax.SAXParseException; import javax.xml.XMLConstants; import javax.xml.bind.JAXBContext; import javax.xml.bind.JAXBException; import javax.xml.bind.Marshaller; import javax.xml.bind.Unmarshaller; import javax.xml.transform.Source; import javax.xml.transform.stream.StreamSource; import javax.xml.validation.Schema; import javax.xml.validation.SchemaFactory; import javax.xml.validation.Validator; import java.io.IOException; import java.io.StringReader; import java.io.StringWriter; /** * @author GuangZe * @version v1.0 * @project: vedio * @description: 这里描述类的用处 * @copyright: © 2020 * @company: * @date 2020/12/16 15:00 */ public class JaxbUtil { public static String validate(String xml, String xsdPath) { String errMsg = null; String[] xmlArr; int lineNum; try { Source root = new StreamSource(JaxbUtil.class.getClassLoader() .getResourceAsStream("xsd/root_elements.xsd")); Source code = new StreamSource(JaxbUtil.class.getClassLoader() .getResourceAsStream("xsd/code_lists.xsd")); Source simple = new StreamSource(JaxbUtil.class.getClassLoader() .getResourceAsStream("xsd/simple_types.xsd")); Source ccd = new StreamSource(JaxbUtil.class.getClassLoader() .getResourceAsStream("xsd/client_centric_data.xsd")); Source customer = new StreamSource(JaxbUtil.class.getClassLoader() .getResourceAsStream("xsd/customer_account.xsd")); Source sub = new StreamSource(JaxbUtil.class.getClassLoader() .getResourceAsStream("xsd/sub_account.xsd")); Source trade = new StreamSource(JaxbUtil.class.getClassLoader() .getResourceAsStream("xsd/trading_account.xsd")); Source[] sourceArr = {code, simple, ccd, customer, sub, trade, root}; Schema schema = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI).newSchema(sourceArr); Validator validator = schema.newValidator(); Source s = new StreamSource(new StringReader(xml)); validator.validate(s); }catch (SAXParseException e){ e.printStackTrace(); xmlArr = xml.split(" "); lineNum = e.getLineNumber(); errMsg = e.getMessage(); if(lineNum<=xmlArr.length && StringUtils.isNotBlank(xmlArr[lineNum-1])){ errMsg +="["+xmlArr[lineNum-1].trim()+"]"; } System.out.println(errMsg); } catch (SAXException e1) { e1.printStackTrace(); errMsg = e1.getMessage(); System.out.println(errMsg); } catch (IOException e2) { e2.printStackTrace(); errMsg = e2.getMessage(); System.out.println(errMsg); } return errMsg; } /** * 序列化 * @param object * @throws JAXBException */ public static String marshall(Object object) throws JAXBException { // 通过映射的类创建XMLContext上下文对象，其中参数为映射的类。 JAXBContext jaxbContext = JAXBContext.newInstance(object.getClass()); // 通过JAXBComtext上下文对象的createMarshaller()方法，创建一个对象java格式转化成XML的格式 Marshaller marshaller = jaxbContext.createMarshaller(); marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8"); //自定义前缀 // NamespacePrefixMapper mapper = new PreferredMapper(); // marshaller.setProperty("com.sun.xml.bind.namespacePrefixMapper", mapper); marshaller.setProperty(Marshaller.JAXB_SCHEMA_LOCATION, "http://www.xxx.com/rootelement root_elements.xsd "); // 最后，将JAVA对象转换到制定的输出位置，其中的object为java对象。 StringWriter writer = new StringWriter(); marshaller.marshal(object, writer); return writer.toString(); } /** * 解析 * @param clazz * @param xml * @return * @throws Exception */ public static Object unmarshaller(Class<?> clazz, String xml) throws Exception { if (StringUtils.isEmpty(xml)) { return null; } // 通过映射的类创建XMLComtext上下文对象，其中参数为映射的类。 JAXBContext jaxbContext = JAXBContext.newInstance(clazz); // 通过JAXBContext上下文对象创建createUnmarshaller()方法，创建XML转换成JAVA对象的格式。 Unmarshaller unmarshaller = jaxbContext.createUnmarshaller(); // 最后，将XML转换成对映的类，转换后需要强制性转换成映射的类 StringReader stringReader = new StringReader(xml); Object object = unmarshaller.unmarshal(stringReader); return object; } public static class PreferredMapper extends NamespacePrefixMapper { @Override public String getPreferredPrefix(String namespaceUri, String suggestion, boolean requirePrefix) { if ("http://www.xxx.com/rootelement".equals(namespaceUri)) { return "ie"; } return suggestion; } } }