Write a simple XML file in the SD card using XmlSerializer

noya · by **noya** » Fri Oct 09, 2009 10:47 am

This java file show how to create a new xml file in the device's SD card.

The steps to make it are:

- create a File object
- link file object to a FileOutputStream
- create a XmlSerializer object and link to the FileOutputStream
- use XmlSerializer methods to create xml tree
- use XmlSerializer flush() method to write data into the new file

NOTICE: I've tested the application in a real device. NOT in the emulator! In order to work correctly into the Emulator i suppose you've got to set up sdcard emulation correctly (in the forum there's a topic about it)

here's the code:

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Using java Syntax Highlighting

/************************************************************************************
 * XmlFileCreator.java
 * Author: Francesco Noya (francesco.noya AT studenti.unimi.it)
 * 
 * This activity shows how to write an xml file into the SD card using
 * org.xmlpull.v1.XmlSerializer
 * 
 * For more informations check these links:
 * 
 * http://developer.android.com/reference/ ... lizer.html
 * 
 * http://www.ibm.com/developerworks/opens ... tml#list11
 * 
 * 
 ************************************************************************************/
 
 
package it.noya.test;
 
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
 
import org.xmlpull.v1.XmlSerializer;
 
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.util.Xml;
import android.widget.TextView;
 
public class XmlFileCreator extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //create a new file called "new.xml" in the SD card
        File newxmlfile = new File(Environment.getExternalStorageDirectory()+"/new.xml");
        try{
                newxmlfile.createNewFile();
        }catch(IOException e){
                Log.e("IOException", "exception in createNewFile() method");
        }
        //we have to bind the new file with a FileOutputStream
        FileOutputStream fileos = null;         
        try{
                fileos = new FileOutputStream(newxmlfile);
        }catch(FileNotFoundException e){
                Log.e("FileNotFoundException", "can't create FileOutputStream");
        }
        //we create a XmlSerializer in order to write xml data
        XmlSerializer serializer = Xml.newSerializer();
        try {
                //we set the FileOutputStream as output for the serializer, using UTF-8 encoding
                        serializer.setOutput(fileos, "UTF-8");
                        //Write <?xml declaration with encoding (if encoding not null) and standalone flag (if standalone not null) 
                        serializer.startDocument(null, Boolean.valueOf(true)); 
                        //set indentation option
                        serializer.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true); 
                        //start a tag called "root"
                        serializer.startTag(null, "root"); 
                        //i indent code just to have a view similar to xml-tree
                                serializer.startTag(null, "child1");
                                serializer.endTag(null, "child1");
                                
                                serializer.startTag(null, "child2");
                                //set an attribute called "attribute" with a "value" for <child2>
                                serializer.attribute(null, "attribute", "value");
                                serializer.endTag(null, "child2");
                        
                                serializer.startTag(null, "child3");
                                //write some text inside <child3>
                                serializer.text("some text inside child3");
                                serializer.endTag(null, "child3");
                                
                        serializer.endTag(null, "root");
                        serializer.endDocument();
                        //write xml data into the FileOutputStream
                        serializer.flush();
                        //finally we close the file stream
                        fileos.close();
                        
                TextView tv = (TextView)this.findViewById(R.id.result);
                        tv.setText("file has been created on SD card");
                } catch (Exception e) {
                        Log.e("Exception","error occurred while creating xml file");
                }
    }
}
 
Parsed in 0.042 seconds,  using GeSHi 1.0.8.4

Result file should be this:

Syntax: [ Download ] [ Hide ]

Using xml Syntax Highlighting

<?xml version='1.0' encoding='UTF-8' standalone='yes' ?>
<root>
  <child1 />
  <child2 attribute="value" />
  <child3>some text inside child3</child3>
</root>
Parsed in 0.001 seconds,  using GeSHi 1.0.8.4

padde · by **padde** » Fri Oct 09, 2009 11:13 am

Nice.. thanks for that. That will come in handy for some future
projects i have in mind

songotho · by **songotho** » Fri Nov 06, 2009 3:04 am

Thanks. Nice tutorials.

base2coder · by **base2coder** » Sat Nov 07, 2009 7:07 am

Hi...thanks for the nice tutorial. But i am trying to create a new xml in my sd card...can you help me that how can i do that?? Thanks a lot for the tutorial...

songotho · by **songotho** » Tue Nov 10, 2009 8:07 am

base2coder wrote:Hi...thanks for the nice tutorial. But i am trying to create a new xml in my sd card...can you help me that how can i do that?? Thanks a lot for the tutorial...

Hi,

You can see AndroiGPSBlog
Maybe it helps you to create file in sdcard

base2coder · by **base2coder** » Thu Nov 12, 2009 7:00 am

Thanks a lot for the link....

mikethelearner · by **mikethelearner** » Fri Feb 26, 2010 2:23 pm

Hi All,

In Java "XMLEncoder" functionality is to write entire data into a object format.

In Java "XMLDecoder" functionality it to read data in a object format.

But, In Android XMLEncoder and XMLDecoder functionality not supported. Is there any alternative for that XMLEncoder and XMLDecoder classes in Android.

Here I used XMLSerializer and XMLPullParser functions for that construction XML and parsing XML. But these Interfaces supports for to write/read the data i.e hard-coded only. I want to write/read data in a Object format.

Please help me. I need Urgent.

Thanks,
mikethelearner.

spring · by **spring** » Fri Mar 05, 2010 8:22 am

good tutorial,thanks for you sharing

RenatoI · by **RenatoI** » Fri Sep 03, 2010 11:01 am

Thx for example. In my case it is all working fine with small files. But if I want to write xml file larger than 16.00KB, it stops writing to the file. Must I set somekind of max limit for FileOutputStream?

devashish · by **devashish** » Fri Feb 11, 2011 7:34 pm

File newxmlfile = new File(Environment.getExternalStorageDirectory()+"/new.xml"); throws an io exception
instead use
File newxmlfile = new File( Environment.getExternalStorageDirectory(),"new.xml");

Mizzhell · by **Mizzhell** » Tue Apr 12, 2011 12:42 pm

I want to continue to add tags after the child3-tag. E.g. I want the app to save playernames and who won. So after every game I want to write to the xml-file. But how do I continue after the last tag within the root?

jodroid · by **jodroid** » Wed Jun 15, 2011 7:17 pm

mizzhell,

What is the app you are trying to develop? It sounds like you are interested in sports which is the direction I am headed as well. I am trying to find some of the bigger high school baseball markets and keep track of stats, records, recruiting etc. all for a single app. Are you working on a similar project or something on a more professional level? I have been looking at online reviews trying to pick up an assistant, have you ever checked out IT staffing agencies for android developer job reviews?

mazen · by **mazen** » Tue Sep 06, 2011 12:31 pm

Hi all,
since you save my time with your tutorial ..
the least thing I can do to register in this forum and say
thank you
....

Krodil · by **Krodil** » Mon Oct 31, 2011 7:48 pm

Hey, thanks for sharing this

I have one novice question: How do you write deeper levels. If I want root>child>child>etc.

In my case i need a root, which will be a user name <NAME> (by key input). Then some children in the same level <experiment1>, <exp2...> etc.
In each of those experiments I need some underlying levels.
|
|root <USER>
<experiment1>
<colour>
<angle>
<experiment2>
<colour>
<angle>

etc.. hope this intuitive figure explains what my words don't

EDIT: the spaces are not shown...its now a bad figure.

piciujupiter · by **piciujupiter** » Fri Nov 04, 2011 10:41 am

E/IOException( 359): exception in createNewFile() method
E/FileNotFoundException( 359): can't create FileOutputStream
E/Exception( 359): error occurred while creating xml file

why do I get this exceptions on this code?

Write a simple XML file in the SD card using XmlSerializer

Write a simple XML file in the SD card using XmlSerializer

Re: Write a simple XML file in the SD card using XmlSerializ

Re: Write a simple XML file in the SD card using XmlSerializ

Re: Write a simple XML file in the SD card using XmlSerializ

Re: Write a simple XML file in the SD card using XmlSerializ

Re: Write a simple XML file in the SD card using XmlSerializ

Re: Write a simple XML file in the SD card using XmlSerializ

Re: Write a simple XML file in the SD card using XmlSerializ

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