JSP request.setAttribute Explained

In JSP, the request.setAttribute(String name, Object value) method is used to set attributes in the request object (HttpServletRequest). This method stores attributes with specified names and values in the request object for sharing data within the scope of the request. This allows for sharing data between different components within the same request handling cycle.

Specifically, the request.setAttribute() method serves the following purposes:

1. Passing data: You can transfer data from one component to another by setting attributes, such as from a Servlet to a JSP page, or passing it to other JSP pages within a JSP page.
2. Shared data: After setting properties, other components can obtain the values of these properties through the request object, achieving the goal of sharing data within the same request processing cycle.
3. Dynamically generate content: In a JSP page, you can use the request.getAttribute() method to retrieve previously set attribute values and then dynamically generate page content based on those values.

The example code below demonstrates how to use the request.setAttribute() method to set attributes in JSP.

<%
String message = "Hello, World!";
request.setAttribute("myMessage", message); // 设置名为"myMessage"的属性
%>

In the above example, we set a property named myMessage to the string “Hello, World!”. Other JSP pages or Servlets can then retrieve and use this property value by using request.getAttribute(“myMessage”).