单击.jsp中的提交按钮后如何保留字符串的值？

Question

我有一个问题，在单击提交按钮后，我丢失了我的 textToConsole 变量中已有的内容。提交后，里面只有“你好”。如何防止丢失文本：“world!”？

<% String textToConsole = "hello"; %>

<form method="POST">
        <div align="center">
            <select name="chooseComboBox" id="chooseComboBox" size="3">
               <option>Option 1</option>
               <option>Option 2</option>
               <option>Option 3</option>
               <option>Option 4</option>
            </select>
            
            <h2 align="center">Enter the range of dates: </h2>
            
            <label>Od:</label>
            <input type="date" name="inputFrom"
               value="2020-01-01"
               min="2000-01-01" max="2022-12-31">
            
            <br><br>
            <label for="inputTo">Do:</label>
            <input type="date" name="inputTo"
               value="2021-01-01"
               min="2000-01-01" max="2022-12-31">
        
            <br><br><br>
                <input type="submit" style="font-size: 20px;" value="Wyeksportuj do pliku">
            </div>
    </form>

    String chooseComboBox = request.getParameter("chooseComboBox");

    if(chooseComboBox != null) {
          textToConsole += "world!";
    }


    <div align="center" id="logConsole">
        <% out.print(textToConsole); %>
    </div>

Answer 1

为了实现这一点，将该值存储在 Httpsession 中并从那里获取它！

单击.jsp中的提交按钮后如何保留字符串的值？

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