JAXB: 通过schema验证XML文件

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