How to make a cartographic line symbol

static void cartographicLineSymbol()throws Exception{
    // Make a new Cartographic Line symbol and sets its properties
    ICartographicLineSymbol cartographicLineSymbolCls = new CartographicLineSymbol();

    // In order to set additional properties like offsets and dash patterns we must create an ILineProperties object
    ILineProperties lineProperties = ((ILineProperties)(cartographicLineSymbolCls));
    lineProperties.setOffset(0);

    // Here's how to do a template for the pattern of marks and gaps
    double pttrn[] = {
        0, 7, 1, 1, 1, 0
    };

    ITemplate templateCls = new Template();
    templateCls.setInterval(1);

    // Add the mark/gap patterns into the Template
    int jx = 0;
    for (int ix = 1; ix <= 3; ix++){
        templateCls.addPatternElement(pttrn[jx], pttrn[jx + 1]);
        jx = jx + 2;
    }

    lineProperties.setTemplateByRef(templateCls);

    //Set the cartographic line properties
    cartographicLineSymbolCls.setWidth(2);
    cartographicLineSymbolCls.setCap(esriLineCapStyle.esriLCSButt);
    cartographicLineSymbolCls.setJoin(esriLineJoinStyle.esriLJSBevel);

    // Make the line red
    IRgbColor rgbColorCls = new RgbColor();
    rgbColorCls.setRed(255);
    rgbColorCls.setGreen(0);
    rgbColorCls.setBlue(0);
    cartographicLineSymbolCls.setColor(rgbColorCls);
}