Question

This code runs perfectly on Java but when I run this on Android platform, it throws TransformerException and FileNotFoundException. Why is it throwing such exceptions? This had bugged me whole day long. The code is as follows:

    public void createXMLInstance() {
    try {
        docBuilder = dbfac.newDocumentBuilder();
        document = docBuilder.newDocument();
        createSampleSMS();
        createDocumentTree();
        printToFile();
        System.out.println("Sample SmsML file generated");
    } catch (ParserConfigurationException pce) {
        pce.printStackTrace();
    }
}

private void createDocumentTree() {
    Element rootEle = document.createElement("Messages");
    document.appendChild(rootEle);
    Iterator<SMS> it = smsList.iterator();
    while (it.hasNext()) {
        SMS msg = (SMS) it.next();
        Element msgEle = createMessageElement(msg);
        rootEle.appendChild(msgEle);
    }
}

private void printToFile() {
    try {
        TransformerFactory transformerFactory = TransformerFactory.newInstance();
        Transformer transformer = transformerFactory.newTransformer();
        DOMSource source = new DOMSource(document);
        StreamResult result = new StreamResult(new File("SmsML.xml"));
        transformer.transform(source, result);
    } catch (TransformerException te) {
        te.printStackTrace();
    }
}

private Element createMessageElement(SMS msg) {

    Element contactEle = document.createElement("Contact");
    contactEle.setAttribute("Number", msg.contactNumber);
    contactEle.setAttribute("Name", msg.sendersName);

    Element msgBodyEle = document.createElement("Message");
    msgBodyEle.setAttribute("Date", msg.getFormattedDate(msg.fullDate));
    msgBodyEle.setAttribute("Time", msg.getFormattedTime(msg.fullDate));
    Text messagDescrip = document.createTextNode(msg.messageBody);
    msgBodyEle.appendChild(messagDescrip);
    contactEle.appendChild(msgBodyEle);
    return contactEle;
}
public void createSampleSMS() {
    smsList.add(new SMS("079399877339", "Tomas", "this is a sample message"));
    smsList.add(new SMS("079398546339", "", "hey how are you Sushan"));
    smsList.add(new SMS("079395486339", "Lusan", "i'm glad that you came to see me"));
    smsList.add(new SMS("079898899556", "Lusan", "i'm not well today"));
    smsList.add(new SMS("078158656522", "Jhu", "he told me he was feeling blue"));
    smsList.add(new SMS("079398546339", "Lusan", "oh that's so sad"));
}

EDIT: Got this form printStackTrace():

01-30 23:08:35.466: I/global(8995): Default buffer size used in BufferedInputStream constructor. It would be better to be explicit if an 8k buffer is required.
01-30 23:08:52.856: W/System.err(8995): javax.xml.transform.TransformerException: java.io.FileNotFoundException: /SmsML.xml (Read-only file system)
01-30 23:08:52.916: W/System.err(8995):     at org.apache.xalan.transformer.TransformerIdentityImpl.createResultContentHandler(TransformerIdentityImpl.java:297)
01-30 23:08:52.956: W/System.err(8995):     at org.apache.xalan.transformer.TransformerIdentityImpl.transform(TransformerIdentityImpl.java:330)
01-30 23:08:52.986: W/System.err(8995):     at my.android.pack.SmsMLActivity.printToFile(SmsMLActivity.java:79)
01-30 23:08:53.026: W/System.err(8995):     at my.android.pack.SmsMLActivity.create(SmsMLActivity.java:58)
01-30 23:08:53.056: W/System.err(8995):     at my.android.pack.SmsMLActivity.onCreate(SmsMLActivity.java:48)
01-30 23:08:53.086: W/System.err(8995):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-30 23:08:53.117: W/System.err(8995):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
01-30 23:08:53.146: W/System.err(8995):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
01-30 23:08:53.176: W/System.err(8995):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)
01-30 23:08:53.206: W/System.err(8995):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
01-30 23:08:53.237: W/System.err(8995):     at android.os.Handler.dispatchMessage(Handler.java:99)
01-30 23:08:53.266: W/System.err(8995):     at android.os.Looper.loop(Looper.java:123)
01-30 23:08:53.296: W/System.err(8995):     at android.app.ActivityThread.main(ActivityThread.java:4627)
01-30 23:08:53.336: W/System.err(8995):     at java.lang.reflect.Method.invokeNative(Native Method)
01-30 23:08:53.376: W/System.err(8995):     at java.lang.reflect.Method.invoke(Method.java:521)
01-30 23:08:53.407: W/System.err(8995):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
01-30 23:08:53.446: W/System.err(8995):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
01-30 23:08:53.476: W/System.err(8995):     at dalvik.system.NativeStart.main(Native Method)
01-30 23:08:53.506: W/System.err(8995): Caused by: java.io.FileNotFoundException: /SmsML.xml (Read-only file system)
01-30 23:08:53.566: W/System.err(8995):     at org.apache.harmony.luni.platform.OSFileSystem.openImpl(Native Method)
01-30 23:08:53.596: W/System.err(8995):     at org.apache.harmony.luni.platform.OSFileSystem.open(OSFileSystem.java:152)
01-30 23:08:53.627: W/System.err(8995):     at java.io.FileOutputStream.<init>(FileOutputStream.java:97)
01-30 23:08:53.656: W/System.err(8995):     at java.io.FileOutputStream.<init>(FileOutputStream.java:168)
01-30 23:08:53.686: W/System.err(8995):     at java.io.FileOutputStream.<init>(FileOutputStream.java:147)
01-30 23:08:53.726: W/System.err(8995):     at org.apache.xalan.transformer.TransformerIdentityImpl.createResultContentHandler(TransformerIdentityImpl.java:287)
01-30 23:08:53.756: W/System.err(8995):     ... 17 more

Answer 1

As the stack trace clearly explains:

01-30 23:08:53.506: W/System.err(8995): Caused by: java.io.FileNotFoundException: /SmsML.xml (Read-only file system)

You cannot read a file that does not exist.

Your problem stems from this line:

StreamResult result = new StreamResult(new File("SmsML.xml"));

That is not how you work with local files in Android, and that assumes that you are trying to parse some file that you downloaded yourself elsewhere in the code.

To learn more about the internal and external storage areas in Android, you can review this section of the documentation.