i want to replace the one data.xml file of power point presentation in java using apache API with other file data.xml
For the reference i want to replace the following file with another power point file.

Following is the code i have tried but xml isnt replacing. I have different XML for both files every time i run after replacing using this code
public static void main(String[] args) {
    // TODO Auto-generated method stub
    final String filename = "C:/Users/skhan/Desktop/game.pptx";
    final String filename1 = "C:/Users/skhan/Desktop/globe.pptx";
    try {
        XMLSlideShow ppt = new XMLSlideShow(new FileInputStream(filename));
        OPCPackage pkg = ppt.getPackage();
        PackagePart data = pkg.getPart(
               PackagingURIHelper.createPartName("/ppt/diagrams/data1.xml"));
        InputStream data1Inp = data.getInputStream();
        XMLSlideShow ppt1 = new XMLSlideShow(new FileInputStream(filename1));
        OPCPackage pkg1 = ppt1.getPackage();
        PackagePart data11 = pkg1.getPart(
               PackagingURIHelper.createPartName("/ppt/diagrams/data1.xml"));
        InputStream data1Inp1 = data11.getInputStream();
        String data1String = GetData(data1Inp);
        String data2String = GetData(data1Inp1);
//i want to replace here
        PrintStream pr = new PrintStream(data.getOutputStream());
        pr.print(data2String);
        pr.close();
        System.out.println("Completed");
    } catch (Exception e) {
        e.printStackTrace();
    }
}
public static String GetData(InputStream input) throws Exception
{
    StringBuilder builder = new StringBuilder();
    int ch;
    while((ch = input.read()) != -1){
        builder.append((char)ch);
    }
    String theString = builder.toString();
    return theString;
}
				
                        
I added the few line after changing in order to save the file. The XMLSlideShow must write to some file after changing or adding.