我正在尝试针对Android的架构检查xml，但在函数的第一行，创建架构工厂实例时，我得到了一个例外。
例外行：
schemaFactory = SchemaFactory.newInstance（XMLConstants.W3C_XML_SCHEMA_NS_URI）;
我还使用了XMLSchema-instance和XMLSchema，但在开头时遇到了同样的例外。
我看到很多其他人都有同样的问题，比如this，但我还没有找到这个问题的答案。
仅供参考 - 我在以下功能中使用它：
public static boolean validateWithExtXSDUsingSAX(String xml, String xsd) throws
ParserConfigurationException, IOException {
try {
SAXParserFactory factory = SAXParserFactory.newInstance();
factory.setValidating(false);
factory.setNamespaceAware(true);
SchemaFactory schemaFactory = null;
try {
schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
} catch (Exception e) {
System.out.println("schema factory error" + e.getMessage());
}
SAXParser parser = null;
try {
factory.setSchema(schemaFactory.newSchema(new Source[] { new StreamSource(xsd) }));
parser = factory.newSAXParser();
} catch (SAXException se) {
System.out.println("SCHEMA : " + se.getMessage()); // problem in
// the XSD
// itself
return false;
}
XMLReader reader = parser.getXMLReader();
reader.setErrorHandler(
new ErrorHandler() {
public void warning(SAXParseException e) throws SAXException {
System.out.println("WARNING: " + e.getMessage()); // do
// nothing
}
public void error(SAXParseException e) throws SAXException {
System.out.println("ERROR : " + e.getMessage());
throw e;
}
public void fatalError(SAXParseException e) throws SAXException {
System.out.println("FATAL : " + e.getMessage());
throw e;
}
});
reader.parse(new InputSource(xml));
return true;
} catch (ParserConfigurationException pce) {
throw pce;
} catch (IOException io) {
throw io;
} catch (SAXException se) {
return false;
}
}
修改：
Android原始版本中包含Java XML验证程序存在一些问题。您可以尝试使用Xerces，您可以在此处下载：
http://code.google.com/p/xerces-for-android/
虽然下载部分没有下载，但您可以通过SVN结帐来下载源代码。
答案 0 :(得分：1)
我遇到了同样的问题，发现了许多类似的问题，但没有关于如何做到这一点的好例子。以下是我使用Xerces-for-Android来完成我的工作。祝你好运：）
以下对我有用：
Android确实支持我们可以使用的一些软件包，我根据以下内容创建了我的xml验证工具：http://docs.oracle.com/javase/1.5.0/docs/api/javax/xml/validation/package-summary.html
我最初的沙盒测试使用java非常顺利，然后我尝试将其移植到Dalvik并发现我的代码无效。有些事情与Dalvik不相同，所以我做了一些修改。
我找到了一个对xerces for android的引用，所以我修改了我的沙箱测试（以下不适用于android，这个例子之后的例子）：
import java.io.File;
import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Source;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import javax.xml.validation.Validator;
import org.w3c.dom.Document;
/**
* A Utility to help with xml communication validation.
*/
public class XmlUtil {
/**
* Validation method.
* Base code/example from: http://docs.oracle.com/javase/1.5.0/docs/api/javax/xml/validation/package-summary.html
*
* @param xmlFilePath The xml file we are trying to validate.
* @param xmlSchemaFilePath The schema file we are using for the validation. This method assumes the schema file is valid.
* @return True if valid, false if not valid or bad parse.
*/
public static boolean validate(String xmlFilePath, String xmlSchemaFilePath) {
// parse an XML document into a DOM tree
DocumentBuilder parser = null;
Document document;
// Try the validation, we assume that if there are any issues with the validation
// process that the input is invalid.
try {
// validate the DOM tree
parser = DocumentBuilderFactory.newInstance().newDocumentBuilder();
document = parser.parse(new File(xmlFilePath));
// create a SchemaFactory capable of understanding WXS schemas
SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
// load a WXS schema, represented by a Schema instance
Source schemaFile = new StreamSource(new File(xmlSchemaFilePath));
Schema schema = factory.newSchema(schemaFile);
// create a Validator instance, which can be used to validate an instance document
Validator validator = schema.newValidator();
validator.validate(new DOMSource(document));
} catch (Exception e) {
// Catches: SAXException, ParserConfigurationException, and IOException.
return false;
}
return true;
}
}
上面的代码必须修改一些才能与xerces for android（http://gc.codehum.com/p/xerces-for-android/）一起使用。您需要SVN才能获得该项目，以下是一些小册子：
download xerces-for-android
download silk svn (for windows users) from http://www.sliksvn.com/en/download
install silk svn (I did complete install)
Once the install is complete, you should have svn in your system path.
Test by typing "svn" from the command line.
I went to my desktop then downloaded the xerces project by:
svn checkout http://xerces-for-android.googlecode.com/svn/trunk/ xerces-for-android-read-only
You should then have a new folder on your desktop called xerces-for-android-read-only
使用上面的jar（最后我会把它变成一个jar，只需将它直接复制到我的源代码中进行快速测试。如果你想这样做，你可以用Ant快速制作jar（{{3} }），我能够得到以下代码来进行我的xml验证：
import java.io.File;
import java.io.IOException;
import mf.javax.xml.transform.Source;
import mf.javax.xml.transform.stream.StreamSource;
import mf.javax.xml.validation.Schema;
import mf.javax.xml.validation.SchemaFactory;
import mf.javax.xml.validation.Validator;
import mf.org.apache.xerces.jaxp.validation.XMLSchemaFactory;
import org.xml.sax.SAXException;
/**
* A Utility to help with xml communication validation.
*/public class XmlUtil {
/**
* Validation method.
*
* @param xmlFilePath The xml file we are trying to validate.
* @param xmlSchemaFilePath The schema file we are using for the validation. This method assumes the schema file is valid.
* @return True if valid, false if not valid or bad parse or exception/error during parse.
*/
public static boolean validate(String xmlFilePath, String xmlSchemaFilePath) {
// Try the validation, we assume that if there are any issues with the validation
// process that the input is invalid.
try {
SchemaFactory factory = new XMLSchemaFactory();
Source schemaFile = new StreamSource(new File(xmlSchemaFilePath));
Source xmlSource = new StreamSource(new File(xmlFilePath));
Schema schema = factory.newSchema(schemaFile);
Validator validator = schema.newValidator();
validator.validate(xmlSource);
} catch (SAXException e) {
return false;
} catch (IOException e) {
return false;
} catch (Exception e) {
// Catches everything beyond: SAXException, and IOException.
e.printStackTrace();
return false;
} catch (Error e) {
// Needed this for debugging when I was having issues with my 1st set of code.
e.printStackTrace();
return false;
}
return true;
}
}
一些备注：
为了创建文件，我创建了一个简单的文件实用程序来将字符串写入文件：
public static void createFileFromString(String fileText, String fileName) {
try {
File file = new File(fileName);
BufferedWriter output = new BufferedWriter(new FileWriter(file));
output.write(fileText);
output.close();
} catch ( IOException e ) {
e.printStackTrace();
}
}
我还需要写一个我可以访问的区域，所以我使用了：
String path = this.getActivity().getPackageManager().getPackageInfo(getPackageName(), 0).applicationInfo.dataDir;
有点hackish，它的确有效。我确信有一种更简洁的方式可以做到这一点，但我想我会分享我的成功，因为我找不到任何好的例子。
答案 1 :(得分：0)
从谷歌存储库下载jar文件xerces-for-android.jar的链接。
如果上述链接不可用，请使用此页面下载：xerces