XML transformation using XSLT to generate the Text file with repeated rows

I am new to XSLT and I am working on a small example where I want to transforman XML input file using XSLT to generate a text file.

Here is my input xml file:

<?xml version="1.0" ?>
<result>
    <users>
        <user>
            <user-name>user 1</user-name>
            <blood-group>A-</blood-group>
            <id>4</id>
            <col1>c1</col1>
            <col2>c2</col2>
            <col4>c4</col4>
        </user>
        <user>
            <user-name>user 2</user-name>
            <blood-group>B+</blood-group>
            <id>3</id>
            <col3>c3</col3>
            <col4>c4</col4>
        </user>
    </users>
</result>

I want to get an output like this after transforming it with XSLT:

User Name | Blood Group | Id | col1 | col2 | col3 | col4
user 1    | A-          | 4  | c1   | null | null | null
user 1    | A-          | 4  | null | c2   | null | null 
user 1    | A-          | 4  | null | null | null | c4
user 2    | B+          | 3  | null | null | c3   | null
user 2    | B+          | 3  | null | null | null | c4

The idea is each record will be repeated by the number of col elements the record is having and each line of the output text will have a value for the particular single col element and all other remaining values of col will be null.

I have created an XSL file like this:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://ift.tt/tCZ8VR"
xmlns:str="http://ift.tt/rkTpc5"
extension-element-prefixes="str">

<xsl:output method="text" encoding="UTF-8"/>

<xsl:template match="/result">
    <xsl:text>User Name | Blood Group | Id | col1 | col2 | col3 | col4&#10;</xsl:text>
    <xsl:for-each select="users/user">
        <xsl:value-of select="str:align(user-name, '          | ', 'left')" />
        <xsl:value-of select="str:align(blood-group, '            | ', 'left')" />
        <xsl:value-of select="str:align(id, '   | ', 'left')" />
        <xsl:value-of select="str:align(col1, '     | ', 'left')" />
        <xsl:value-of select="str:align(col2, '     | ', 'left')" />
        <xsl:value-of select="str:align(col3, '     | ', 'left')" />
        <xsl:value-of select="col4" />
        <xsl:if test="position()!=last()">
            <xsl:text>&#10;</xsl:text>
        </xsl:if>
    </xsl:for-each>
</xsl:template>
</xsl:stylesheet>

With this XSL I got the output as:

User Name | Blood Group | Id | col1 | col2 | col3 | col4
user 1    | A-          | 4  | c1   | c2   |      | c4
user 2    | B+          | 3  |      |      | c3   | c4

I am not clear on what functions can be used to get the desired output. Can someone please help me?

The java code that helps me to do the transformation is:

public static void main(String[] args) {
        String path="/";
        String xml = path+"input.xml";
        String xslt = path+"input.xsl";
        String output = path+"output.txt";
        try {
            TransformerFactory tf = TransformerFactory.newInstance();
            Transformer tr = tf.newTransformer(new StreamSource(xslt));
            tr.transform(new StreamSource(xml), new StreamResult(
                    new FileOutputStream(output)));

            System.out.println("Output to " + output);
        } catch (Exception e) {
            System.out.println(e);
            e.printStackTrace();
        }
    }