如何在两个或多个 jsp 页面中检索选择的选项标记值答案

【问题标题】：how a option tag value selected can be retrieved in two or more jsp pages如何在两个或多个 jsp 页面中检索选择的选项标记值
【发布时间】：2015-10-06 05:19:24
【问题描述】：

purchase.jsp

 <form action="view.jsp" method="post">
    <select id='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 = "submit" value="Submit"
    </form>

view.jsp

    <script type="text/javascript">

        function setAction(nPage){

            document.forms[0].action = nPage;
        }
    </script>
<form>
    <select onchange="setAction(this.value)">
    <option value=''> Make a selection </option>
    <option value='PDF2.jsp'> PDF</option>
    <option value='XLS2.jsp'> XLS </option>
    <option value='DOC.jsp'> DOC </option>
    <option value='XLSX2.jsp'> XLSX </option>
    </select>
<input type="submit" value="Submit">
</form>

首先我会从purchase.jsp中选择company，然后我会点击提交，它会转到view.jsp，然后我会再次选择PDF2.jsp，然后点击提交，它将转到PDF2.jsp页面。现在我的问题是如何将我在purchase.jsp中选择的公司打印到PDF2.jsp。所以这里有3个jsp页面，在第一个jsp页面中选择的值应该打印在第三个jsp页面中，但是顺序应该从第一个jsp（purchase.jsp）到第二个jsp（view.jsp）和第二个jsp（@987654331 @) 到第三个 jsp(PDF2.jsp)。

PDF2.jsp

<body>
<form>
<%
String cat=request.getParameter("category");
System.out.println("It is" +cat);
%>
</form>
</body>

【问题讨论】：

一种选择是将其存储在隐藏值中。
可以将其存储在会话变量中
@charlietfl 是的，它可以存储在会话变量中。现在我也意识到了

标签： javascript java jquery jsp servlets

【解决方案1】：

在 view.jsp 中，像这样设置会话

<%
session.setAttribute("category",category);
%>

您可以像这样在任何其他 jsp 中检索它

String company= (String)session.getAttribute("category");

【讨论】：

【解决方案2】：

purchase.jsp

<form action="view.jsp" method="post">
<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="submit" value="Submit"/>

</form>

view.jsp

<script type="text/javascript">

    function setAction(nPage){

        document.forms[0].action = nPage;
    }
</script>
<form>
<% 
String category=request.getParameter("category");
session.setAttribute("cat",category);
%>
<select onchange="setAction(this.value)">
<option value=''> Make a selection </option>
<option value='PDF2.jsp'> PDF</option>
<option value='XLS2.jsp'> XLS </option>
<option value='DOC.jsp'> DOC </option>
<option value='XLSX2.jsp'> XLSX </option>
</select>
<br/>

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

PDF2.jsp

<body>
<% 
Connection conn = null;

try 
{ 
    Class.forName("com.mysql.jdbc.Driver");
    conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/marketing_database","root","root");
    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");
    Map parameters = new HashMap();
    parameters.put("category",session.getAttribute("cat"));
    JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport,parameters,conn);
    byte bytes[] = new byte[10000]; 
    JRPdfExporter exporter = new JRPdfExporter();
    ByteArrayOutputStream PDFStream = new ByteArrayOutputStream(); 
    exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint); 
    exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, PDFStream); 
    exporter.exportReport(); 
    System.out.println("Size of byte array:"+PDFStream.size()); 
    bytes = PDFStream.toByteArray(); 
    response.setContentType("application/pdf"); 
    System.out.println("After JasperPrint = 1"); 
    response.setContentLength(bytes.length); 
    System.out.println("After JasperPrint = 2"); 
    PDFStream.close(); 
    System.out.println("After JasperPrint = 3"); 

    OutputStream outputStream = response.getOutputStream(); 
    System.out.println("After JasperPrint = 4"); 
    outputStream.write(bytes, 0, bytes.length); 
    outputStream.flush(); 
    outputStream.close(); 

}
catch(Exception e) 
{e.printStackTrace();} 

%>
</body>

【讨论】：