在Android 4.0上调用SchemaFactory.newInstance时出现异常
我有一个android 4.0应用程序,它尝试按照android SDK中的建议调用以下内容:在Android 4.0上调用SchemaFactory.newInstance时出现异常,android,Android,我有一个android 4.0应用程序,它尝试按照android SDK中的建议调用以下内容: SchemaFactory sf = SchemaFactory.newInstance(javax.xml.XMLConstants.W3C_XML_SCHEMA_NS_URI); 但这给了我以下例外: java.lang.IllegalArgumentException: http://www.w3.org/2001/XMLSchema 我的代码: btnSearch.setOnClic
SchemaFactory sf =
SchemaFactory.newInstance(javax.xml.XMLConstants.W3C_XML_SCHEMA_NS_URI);
但这给了我以下例外:
java.lang.IllegalArgumentException: http://www.w3.org/2001/XMLSchema
我的代码:
btnSearch.setOnClickListener(new Button.OnClickListener(){
public void onClick(View v) {
try{
//no code before this line and exception threw right here.
SchemaFactory sf = SchemaFactory.newInstance(javax.xml.XMLConstants.W3C_XML_SCHEMA_NS_URI);
....
}
我也有类似的问题。这个常数显然取决于底层系统,我发现我无法让常规的xerces与Android一起工作,但是我确实找到了适用于Android的xerces,我找到了它。下面是设置的详细信息和一些示例代码。祝你好运:) 以下几点对我很有用:
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(最终我会将其制作成一个jar,直接复制到我的源代码中进行快速测试。如果您希望这样做,可以使用Ant()快速制作jar),我能够获得以下用于xml验证的内容:
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;
}
}
一些旁注:
为了创建文件,我制作了一个简单的文件实用程序来向文件写入字符串:
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,所以我利用了:
String path = this.getActivity().getPackageManager().getPackageInfo(getPackageName(), 0).applicationInfo.dataDir;
有点老套,它很管用。我相信有一种更简洁的方法可以做到这一点,但我想我会分享我的成功,因为我没有找到任何好的例子。与这个问题相关:
String path = this.getActivity().getPackageManager().getPackageInfo(getPackageName(), 0).applicationInfo.dataDir;