从一个简单的小实例分析JSP+Servelt与JSP+Struts2框架的区别

Posted 2020-10-06 Jay36

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最近在学struts2，struts2相比以前的JSP+Servlet，在处理流程上的更简单，我们就一个小实例来具体分析一下。

实例内容如下：

实现一个简单的注册页面包括：用户名、密码、重复密码、年龄、出生日期、毕业日期

要求如下：
用户名的长度在4-6之间
密码的长度在4-6之间
重复密码与密码相等
年龄在10-50之间
出生日期在毕业日期之前

输入错误返回原页面，并在原页面的文本框后面显示具体的错误信息。正确输入则跳入下个页面将信息显示出来。

1、JSP+Servlet

1）我们编写注册页面register.jsp

注册页面，不使用struts标签库的话，基本上大同小异，唯一的区别在form中action选项上，这里面的servlet自然要跳到RegisterServlet上进行相应的信息处理。我们先各自处理，然后再来比较吧。

[html] view plain copy

<body>
<h1>用户注册</h1>
<form action="RegisterServlet" method="post">
username:<input type="text" name="username"><br>
password:<input type="password" name="password"><br>
repassword:<input type="password" name="repassword"><br>
age:<input type="text" name="age"><br>
birthday:<input type="text" name="birthday"><br>
graduate:<input type="text" name="graduate"><br>
<input type="submit" value="submit">
</form>
</body>

2）因为这些属性都是属于注册用户的，我们再构建一个User类

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private String username;
private String password;
private String repassword;
private int age;
private Date birthday;
private Date graduate;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getRepassword() {
return repassword;
}
public void setRepassword(String repassword) {
this.repassword = repassword;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public Date getGraduate() {
return graduate;
}
public void setGraduate(Date graduate) {
this.graduate = graduate;
}

3）输入效验可以分为客户端效验和服务器端的效验，客户端的效验是将验证代码用javascript写到页面中，这里面我们统一用服务器端效验。编写RegisterServlet

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protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//从页面传过来的数据都是字符形式的，我们要进行相应的转换
String username=request.getParameter("username");
String password=request.getParameter("password");
String repassword=request.getParameter("repassword");
int age=Integer.valueOf(request.getParameter("age"));
String birthday=request.getParameter("birthday");
String graduate=request.getParameter("graduate");
Date graduate1=null;
Date birthday1=null;
Map<String, String> errors = new HashMap<String, String>();
if (username == null)
{
errors.put("username", "用户名不能为空");
} else
{
if (username.length()<4||username.length()>6)
{
errors.put("username", "用户名必须是4到6位");
}
}
if (password == null)
{
errors.put("password", "密码不能为空");
} else
{
if (password.length()<4||password.length()>6)
{
errors.put("password", "密码必须是4-6位数字");
}
}
if (repassword ==null)
{
errors.put("repassword", "确认密码不能为空");
} else
{
if (!(password.equals(repassword)))
{
errors.put("repassword", "确认密码必须与密码输入一致");
}
}
if(age>50||age<10)
{
errors.put("age", "年龄无效");
}
if(birthday!=null)
{
DateFormat df=new SimpleDateFormat("yyyy-MM-dd");
try{
birthday1=df.parse(birthday);
}catch(Exception e)
{
errors.put("birthday", "日期格式不正确");
}
}else{
errors.put("birthday", "生日不能为空");
}
if(graduate!=null)
{
DateFormat df=new SimpleDateFormat("yyyy-MM-dd");
try{
graduate1=df.parse(graduate);
}catch(Exception e)
{
errors.put("graduate", "日期格式不正确");
}
}else{
errors.put("graduate", "毕业日期不能为空");
}
if(null!=graduate1&&null!=birthday1)
{
Calendar c1=Calendar.getInstance();
c1.setTime(birthday1);
Calendar c2=Calendar.getInstance();
c2.setTime(graduate1);
if(!c1.before(c2))
{
errors.put("graduate", "毕业日期出生日期不匹配");
}
}
<span style="color:#FF0000;">if(errors.size()==0)
{
User user=new User();
user.setUsername(username);
user.setAge(age);
user.setPassword(password);
user.setRepassword(repassword);
user.setBirthday(birthday1);
user.setGraduate(graduate1);
request.setAttribute("user", user);
request.getRequestDispatcher("result.jsp").forward(request, response);
}else
{
request.setAttribute("errors", errors);
request.setAttribute("username", username);
request.setAttribute("password",password);
request.setAttribute("birthday", birthday);
request.setAttribute("graduate",graduate);
request.setAttribute("age",age);
request.getRequestDispatcher("register.jsp").forward(request, response);
}</span>
}

4)然后我们编写一下result.jsp结果页面和修改一下register.jsp页面（出现错误后跳转，显示相应的错误信息）

result.jsp页面

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<body>
username:${user.username}<br>
password:${user.password}<br>
age:${user.age}<br>
birthday:${user.birthday}<br>
graduate:${user.graduate}<br>
</body>

[html] view plain copy

<body>
<h1>用户注册</h1>
<form action="RegisterServlet" method="post">
username:<input type="text" name="username" value="${username}">${errors.username}<br>
password:<input type="password" name="password">${errors.password}<br>
repassword:<input type="password" name="repassword">${errors.repassword}<br>
age:<input type="text" name="age" value="${age}">${errors.age}<br>
birthday:<input type="text" name="birthday" value="${birthday}">${errors.birthday}<br>
graduate:<input type="text" name="graduate" value="${graduate}">${errors.graduate}<br>
<input type="submit" value="submit">
</form>