How to save the content of the previous page on the next page in Java

There are four ways to save the content of the previous page for use on the next page in a Java Web application: Use a session object to store user session information. Use request forwarding to redirect the request and pass the original request and response objects. Use hidden form fields to pass data when sending a form. Use URL parameters as query strings appended to the URL.

How to save the content of the previous page in Java for use on the next page

In Java Web Application In programs, it is often necessary to retain the content of the previous page on the next page. This can be achieved through the following methods:

1. Using the session object

The session object stores information about the current user session, including request and response data. To save content using a session object, follow these steps:

<code class="java">// 获取会话对象
HttpSession session = request.getSession();

// 将内容存储在会话对象中
session.setAttribute("key", "value");</code>

On the next page, you can retrieve the stored content via:

<code class="java">HttpSession session = request.getSession();
String value = (String) session.getAttribute("key");</code>

2. Using request forwarding

Request forwarding redirects a request to another resource, passing the original request and response objects to the new resource. This allows the new resource to access the data in the original request. To save content using request forwarding, follow these steps:

<code class="java">// 将请求转发到另一个资源
RequestDispatcher dispatcher = request.getRequestDispatcher("/nextPage.jsp");
dispatcher.forward(request, response);</code>

On the next page, you can access the data from the original request using:

<code class="java">String value = request.getParameter("key");</code>

3. Use a hidden form Fields

Hidden form fields are invisible form elements used to pass data when sending a form. To save content using hidden form fields, follow these steps:

<code class="html"><form action="nextPage.jsp" method="post">
  <input type="hidden" name="key" value="value">
  <input type="submit" value="Submit">
</form></code>

On the next page, you can access the data in the hidden form fields using:

<code class="java">String value = request.getParameter("key");</code>

4. Use URL parameters

URL parameters are query strings appended to the URL to pass data. To save content using URL parameters, follow these steps:

<code class="java">// 将内容作为 URL 参数附加到 URL
String url = "nextPage.jsp?key=value";

// 重定向到带参数的 URL
response.sendRedirect(url);</code>

On the next page, you can access the data in the URL parameters using:

<code class="java">String value = request.getParameter("key");</code>

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