How to pass the value selected from dropdown menu to jasper report and display the records

I have "Company Name","Contact Person","Phone Number" in my drop down menu. When i select "Contact Person" and "Company" and enter some name in text box and press "search" button it should display the record containing that person name. If we dont enter any name in the text box and select "Contact Person" and "Company" and press "search" button it should display all the records of "Contact Person".Like wise if i select "Phone" and "Company" and enter some number in the text box it should display that record otherwise if we dont enter any number then it should display all the records of phone number.Here is my code below:

purchase.jsp

<form action="view.jsp" method="post">
<select name="complan">
<option value="">Make a selection</option>
<option value="Company Name">Company Name</option>
<option value="Contact Person">Contact Person</option>
<option value="Phone Number">Phone Number</option>
</select>
<select name="category">
<option value=""> Make a selection </option>
<option value="company">company</option>
<option value="institution">institution</option>
<option value="hospital">hospital</option>
<option value="Others">Others</option>
</select>
<input type="text" name="search"/>
<input type="submit" value="Submit"/>
</form>

view.jsp

<form>
<% 
String search=request.getParameter("search");
session.setAttribute("sea",search);
String category=request.getParameter("category");
session.setAttribute("cat",category);
String complan = request.getParameter("complan");
session.setAttribute("com",complan);
%>
<select onchange="setAction(this.value)">
<option value=''> Make a selection </option>
<option value='sample.jsp'> PDF</option>
<option value='XLS_LEAD.jsp'> XLS </option>
<option value='DOC_LEAD.jsp'> DOC </option>
<option value='XLSX_LEAD.jsp'> XLSX </option>
</select>
<br/>

<input type="submit" value="Submit">
</form>

sample.jsp

<body>
<%
Connection conn = null;
String sear=(String)session.getAttribute("sea");
String cate=(String)session.getAttribute("cat");
String comp=(String)session.getAttribute("com");

System.out.println("1 is:"+sear);
System.out.println("2 is:"+cate);
System.out.println("3 is:"+comp);
try 
{
    Class.forName("com.mysql.jdbc.Driver");
    conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/marketing_database","root","root");
    String sql="select * from lead where Category='" + cate.replaceAll("\\'","''") + "'";
    if(sear!=null && sear.trim().length()>0)
    {
        sql+=" AND Company_Name like '" + sear.replaceAll("\\'","''") + "%'";
        }
    else if(sear!=null && sear.trim().length()>0)
    {
        sql+=" AND Contact_Person like '" + sear.replaceAll("\\'","''") + "%'";
    }
    else
    {
        sql+=" AND Phone like '" + sear.replaceAll("\\'","''") + "%'";
    }

    String jrxmlFile ="D:/dev/tools/jasper files/report10.jrxml";
    InputStream input = new FileInputStream(new File(jrxmlFile));
    JasperDesign jasperDesign = JRXmlLoader.load(input);

    System.out.println("Compiling Report Designs");
    JasperReport jasperReport = JasperCompileManager.compileReport(jasperDesign);

    System.out.println("Creating JasperPrint Object");
    HashMap<String,Object> map = new HashMap<String,Object>();
    map.put("sql",sql);
            byte[] bytes = JasperRunManager.runReportToPdf(jasperReport, map, conn);

            response.setContentType("application/pdf");
            response.setContentLength(bytes.length);
            ServletOutputStream outStream = response.getOutputStream();
            outStream.write(bytes, 0, bytes.length);
            outStream.flush();
            outStream.close();
}
catch(Exception e) 
{e.printStackTrace();} 

        %>
</body>

report10.jrxml

<parameter name="sql" class="java.lang.String"/>
    <queryString>
    <![CDATA[$P!{sql}]]>
</queryString>

Solution

You got strange code:

if(sear!=null && sear.trim().length()>0)
{
    sql+=" AND Company_Name like '" + sear.replaceAll("\\'","''") + "%'";
    }
else if(sear!=null && sear.trim().length()>0)
{
    sql+=" AND Contact_Person like '" + sear.replaceAll("\\'","''") + "%'";
}

It will never enter your else if, hence

if (true){//i go here}else if (true){//How can I arrive here if it was false, 
  hence the else says it needs to be false}

So on creating your sql you need to do you if statements on the base of what you need.

if (i have comany and person) I do this...

if (i have phone) I do this ecc.

Try to improve your code some, if you have still problem pass a comment...

Since you sent some code by email I will provide additional clues to resolve

String sql="select * from lead where Category Like'" + cate.replaceAll("\\'","''") + "%'";


//We check that user has input something in the search box
if(sear!=null && sear.trim().length()>0)
{
   boolean isnumber = isNumber(sear); //isNumber(String text) is a metod that you need to create;
   //I have not really understand what excatly you like,
   //but it could be like this
   if (isnumber || complan.equals("Phone Number")){
     sql+=" AND Phone like '" + sear.replaceAll("\\'","''") + "%'";
   } else if (complan.equals("Contact Person")){
     sql+=" AND Contact_Person like '" + sear.replaceAll("\\'","''") + "%'";
   }else{
     sql+=" AND Company_Name like '" + sear.replaceAll("\\'","''") + "%'";
   }
}else{
  //we do nothing since we like to show all records 
}

In this case

if input is a number or selected Phone number it search on the phone number column.

if input is not a number and search using Contact person it selects on that column

Otherwise search on company name

I don't really like the part of the number since you have the phone number in the options to select, be aware you can never find a company named 1234, since we will search on phone number... Why not search as user have indicated?, if not indicated select a default...

If you don't want to find everything that matches the input but only exact hits you need to change

like '" + sear.replaceAll("\\'","''") + "%'"

= '" + sear.replaceAll("\\'","''") + "'"