e1047. running java code in a jsp page.txt

来自「这里面包含了一百多个JAVA源文件」· 文本 代码 · 共 27 行

Java code fragments in a JSP page is called a scriptlet. This example demonstrates how to include scriptlets in a JSP page. Use the out variable to add text to the generated output: 
    <%
        double rand = Math.random();
        if (rand < .1) {
            out.println("you win!");
        } else {
            out.println("try again");
        }
    %>

This example defines a method that can be used in a scriptlet in the page: 
    <%!
        String getMsg() {
            double rand = Math.random();
            if (rand < .1) {
                return "you win!";
            } else {
                return "try again";
            }
        }
    %>
    <%
        // Use the method
        out.println(getMsg());
    %>

There are a number of implicit objects available to scriptlets - application, config, exception, out, pageContext, request, response, and session. These implicit objects are described in the JSP 1.2 Specification available at http://java.sun.com.