使用android app验证xml架构

时间:2011-11-23 19:58:28

标签: java android xml

所以目前我正在尝试设计一个自定义的xml架构,并且android应用程序应该使用该架构。

有没有办法使用android验证xml架构?

2 个答案:

答案 0 :(得分:0)

据我所知,无法使用W3C XML Schema(see that post以及更多类似的SO)。

如果您要验证自定义xml格式并且此格式是否存在且仅在您的应用程序中使用,我建议您通过使用xmlpullparser进行解析来以编程方式进行验证。如果interop是你的目的,那就去服务器端验证(基于W3C XML Schema或RelaxNG等架构语言)和客户端简单完整性检查(android毕竟是一个嵌入式平台)......

Another xml schema-related thought of mine

答案 1 :(得分:0)

我发现我无法让常规的xerces与Android一起工作,但我确实找到了Xerces-for-Android,我开始工作了。以下是设置和一些示例代码的详细信息。祝你好运:)

以下对我有用:

  1. 创建验证实用程序。
  2. 在Android操作系统上同时获取xml和xsd文件并对其使用验证实用程序。
  3. 使用Xerces-For-Android进行验证。
  4. 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。