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e1047. Running Java Code in a JSP Page

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.