<%

// 获取表单参数

JSP判断实例演示  第1张

String name = request.getParameter(

ame" String ageStr = request.getParameter("e" int age = 0;

String message = " String resultClass = " // 验证年龄是否为数字

if (ageStr != null && !ageStr.trim().isEmpty()) {

try {

age = Integer.parseInt(ageStr);

// 使用if-else进行条件判断

if (age < 0) {

message = "不能为负数!" resultClass = "danger" } else if (age < 18) {

message = name + "您是未成年人(" age + "),需要家长监护。" resultClass = "" } else if (age >= 18 && age < 60) {

message = name + "您是成年人(" + age + "岁),欢迎使用本系统。" resultClass = "success" } else {

message = name + ",您是老年人(" + age + "岁),感谢您的使用。" resultClass = "info" }

} catch (NumberFormatException e) {

message = "请输入有效的年龄数字!" resultClass = "danger" }

} else {

message = "请输入年龄信息!" resultClass = "danger" }

%>

"

验证结果:

<%= message %>

<%

// 使用switch进行额外信息显示

String additionalInfo = " if (age >= 0) {

switch (age / 10) {

case 0:

additionalInfo = "处于儿童期。" break;

case 1:

additionalInfo = "处于青少年期。" break;

case 2:

case 3:

case 4:

case 5:

additionalInfo = "您处于成年期。" break;

default:

additionalInfo = "处于老年期。" }

}

if (!additionalInfo.isEmpty()) {

%>

附加信息: <%= additionalInfo %>

<%

}

%>