JAXB: 通过schema验证XML文件

最新推荐文章于 2021-07-26 14:58:12 发布

转载最新推荐文章于 2021-07-26 14:58:12 发布 · 2.9k 阅读

文章标签：

#schema #xml #jaxb #validation #object #file

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本文介绍了一种使用Java和JAXB进行XML文件解析的方法，并通过指定的XSD文件验证XML的有效性。文中提供了详细的示例代码，展示了如何加载schema、创建marshaller及验证过程中错误的处理。

在使用JAXB解析XML文件的时候我们有时候可能会需要通过schema文件验证XML的格式，接上文的XMLParser.java

示例代码如下：

Java代码

public static Object unmarshal(InputStream xml, Class<?> clazz) throws SAXException {
Object obj = null ;
ValidationEventCollector vec = new ValidationEventCollector();
try {
SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
Schema schema = sf.newSchema(new File( "C://eclipse//workspace1//STAF//test//employees.xsd" ));
JAXBContext jc = JAXBContext.newInstance(clazz.getPackage().getName());
Unmarshaller u = jc.createUnmarshaller();
u.setSchema(schema);
u.setEventHandler(vec);
obj = u.unmarshal(xml);
} catch (JAXBException e) {
throw new RuntimeException( "Can't unmarshal the XML file, error message: " + e.getMessage());
} finally {
if (vec != null && vec.hasEvents()) {
for (ValidationEvent ve : vec.getEvents()) {
String msg = ve.getMessage();
ValidationEventLocator vel = ve.getLocator();
int line = vel.getLineNumber();
int column = vel.getColumnNumber();
System.out.println();
System.err.println("At line " + line + ", column " + column + ": " + msg);
}
}
}
return obj;
}

public static Object unmarshal(InputStream xml, Class<?> clazz) throws SAXException {
		Object obj = null;
		
		ValidationEventCollector vec = new ValidationEventCollector();
		
		try {
			SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
            Schema schema = sf.newSchema(new File("C://eclipse//workspace1//STAF//test//employees.xsd"));
			
			JAXBContext jc = JAXBContext.newInstance(clazz.getPackage().getName());
			Unmarshaller u = jc.createUnmarshaller();
			u.setSchema(schema);
            u.setEventHandler(vec);
			
			obj = u.unmarshal(xml);
		} catch (JAXBException e) {
			throw new RuntimeException("Can't unmarshal the XML file, error message: " + e.getMessage());
		} finally {
			if(vec != null && vec.hasEvents()) {
            	for(ValidationEvent ve : vec.getEvents()) {
            		String msg = ve.getMessage();
            		ValidationEventLocator vel = ve.getLocator();
            		int line = vel.getLineNumber();
            		int column = vel.getColumnNumber();
            		System.out.println();
            		System.err.println("At line " + line + ", column " + column + ": " + msg);
            	}
            }
		}
		
		return obj;
	}

该代码段适用于单一schema，或者在classpath中的多schema验证，如果是classpath外的多schema验证，请结合参考该文：XML validation for multiple schemas 验证使用多个XSD schema的XML文件