Is it possible to generate reports dynamically using Jasper Reports without generating a jasper for each report?

Question

I have to generate reports based on various parameters which would be provided dynamically. In certain contexts, the parameters may be null. For example, from the table

Answer 1

The sample of using the JasperReport API for generating report dynamically:

    //JasperDesign
    JasperDesign jasperDesign = new JasperDesign();
    jasperDesign.setName("The dynamically generated report");
    jasperDesign.setPageWidth(595);
    jasperDesign.setPageHeight(842);
    jasperDesign.setColumnWidth(515);
    jasperDesign.setColumnSpacing(0);
    jasperDesign.setLeftMargin(40);
    jasperDesign.setRightMargin(40);
    jasperDesign.setTopMargin(50);
    jasperDesign.setBottomMargin(50);

    //Query
    JRDesignQuery query = new JRDesignQuery();
    query.setText("SELECT * FROM Address $P!{OrderByClause}");
    jasperDesign.setQuery(query);

    //Fields
    JRDesignField field = new JRDesignField();
    field.setName("Id");
    field.setValueClass(java.lang.Integer.class);
    jasperDesign.addField(field);

    field = new JRDesignField();
    field.setName("FirstName");
    field.setValueClass(java.lang.String.class);
    jasperDesign.addField(field);

    field = new JRDesignField();
    field.setName("LastName");
    field.setValueClass(java.lang.String.class);
    jasperDesign.addField(field);

    //some code

    //Detail
    band = new JRDesignBand();
    band.setHeight(40);

    JRDesignStaticText staticText = new JRDesignStaticText();
    staticText.setX(0);
    staticText.setY(0);
    staticText.setWidth(60);
    staticText.setHeight(20);
    staticText.setMode(ModeEnum.OPAQUE);
    staticText.setHorizontalAlignment(HorizontalAlignEnum.LEFT);
    staticText.setStyle(boldStyle);
    staticText.setText("ID: ");
    staticText.getLineBox().getLeftPen().setLineWidth(1);
    staticText.getLineBox().getTopPen().setLineWidth(1);
    staticText.getLineBox().setLeftPadding(10);
    band.addElement(staticText);

    textField = new JRDesignTextField();
    textField.setX(60);
    textField.setY(0);
    textField.setWidth(200);
    textField.setHeight(20);
    textField.setHorizontalAlignment(HorizontalAlignEnum.LEFT);
    textField.setStyle(normalStyle);
    expression = new JRDesignExpression();
    expression.setValueClass(java.lang.Integer.class);
    expression.setText("$F{Id}");
    textField.setExpression(expression);
    textField.getLineBox().getTopPen().setLineWidth(1);
    textField.getLineBox().getRightPen().setLineWidth(1);
    textField.getLineBox().setLeftPadding(10);
    band.addElement(textField);

    staticText = new JRDesignStaticText();
    staticText.setX(0);
    staticText.setY(20);
    staticText.setWidth(60);
    staticText.setHeight(20);
    staticText.setMode(ModeEnum.OPAQUE);
    staticText.setHorizontalAlignment(HorizontalAlignEnum.LEFT);
    staticText.setStyle(boldStyle);
    staticText.setText("Name: ");
    staticText.getLineBox().getLeftPen().setLineWidth(1);
    staticText.getLineBox().getBottomPen().setLineWidth(1);
    staticText.getLineBox().setLeftPadding(10);
    band.addElement(staticText);

    textField = new JRDesignTextField();
    textField.setStretchWithOverflow(true);
    textField.setX(60);
    textField.setY(20);
    textField.setWidth(200);
    textField.setHeight(20);
    textField.setPositionType(PositionTypeEnum.FLOAT);
    textField.setStyle(normalStyle);
    expression = new JRDesignExpression();
    expression.setValueClass(java.lang.String.class);
    expression.setText("$F{FirstName} + \" \" + $F{LastName}");
    textField.setExpression(expression);
    textField.getLineBox().getRightPen().setLineWidth(1);
    textField.getLineBox().getBottomPen().setLineWidth(1);
    textField.getLineBox().setLeftPadding(10);
    band.addElement(textField);

    ((JRDesignSection) jasperDesign.getDetailSection()).addBand(band);

You can find more samples in %JasperReportsFolder%/demo/samples folder from the JasperReports distribution package.