Java之通过反射机制选择servlet中的对应的方法
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2022-03-20 10:34:26
此方法用于在对Javaee开发中的通过对应的名称而选择servlet中的对应的方法 注：主要代码如下 示例 注：在后面的jsp页面中提交form表单中的 action="<%=request.getContextPath() %>/saveTeacher.ado"可以直接通过反射机制调用servle ......
此方法用于在对javaee开发中的通过对应的名称而选择servlet中的对应的方法
注：主要代码如下
protected void doget(httpservletrequest req, httpservletresponse resp) throws servletexception, ioexception {
/**
* 这是设置浏览器编码的问题
*/
req.setcharacterencoding("utf-8");
resp.setcontenttype("text/html,charset=utf-8");
string servletpath = req.getservletpath();
string methodname = servletpath.substring(1);
methodname = methodname.substring(0, methodname.length()-4);
system.out.println(methodname);
try {
/**
* 根据反射机制选择servlet对应的方法
*/
method method = getclass().getdeclaredmethod(methodname, httpservletrequest.class,
httpservletresponse.class);
/**
* 利用反射调用对应的方法
*/
method.invoke(this, req,resp);
} catch (exception e) {
e.printstacktrace();
system.out.println("这里是登录的时候反射机制的地方出错了！");
req.getrequestdispatcher("error.jsp").forward(req, resp);
}
}
@override
protected void dopost(httpservletrequest req, httpservletresponse resp) throws servletexception, ioexception {
doget(req, resp);
}
示例
注：在后面的jsp页面中提交form表单中的 action="<%=request.getcontextpath() %>/saveteacher.ado"可以直接通过反射机制调用servlet中的saveteacher方法
public class administratorsservlet extends httpservlet {
private static final long serialversionuid = 1l;
@override
protected void doget(httpservletrequest req, httpservletresponse resp) throws servletexception, ioexception {
/**
* 这是设置浏览器编码的问题
*/
req.setcharacterencoding("utf-8");
resp.setcontenttype("text/html,charset=utf-8");
string servletpath = req.getservletpath();
string methodname = servletpath.substring(1);
methodname = methodname.substring(0, methodname.length()-4);
system.out.println(methodname);
try {
/**
* 根据反射机制选择servlet对应的方法
*/
method method = getclass().getdeclaredmethod(methodname, httpservletrequest.class,
httpservletresponse.class);
/**
* 利用反射调用对应的方法
*/
method.invoke(this, req,resp);
} catch (exception e) {
e.printstacktrace();
system.out.println("这里是登录的时候反射机制的地方出错了！");
req.getrequestdispatcher("error.jsp").forward(req, resp);
}
}
@override
protected void dopost(httpservletrequest req, httpservletresponse resp) throws servletexception, ioexception {
doget(req, resp);
}
/**
* 基于对教师的基本操作
*/
/**
* 添加一个教师
* @param req
* @param resp
* @throws servletexception
* @throws ioexception
*/
private void saveteacher(httpservletrequest req, httpservletresponse resp) throws servletexception, ioexception {
try {
teachers teacher = new teachers();
teacher.setteacherid(integer.parseint(req.getparameter("teacherid")));
teacher.setteachername(req.getparameter("teachername"));
teacher.setsex(req.getparameter("sex"));
teacher.setphoneno(req.getparameter("phoneno"));
teacher.setaddress(req.getparameter("address"));
teacher.setbirthday(new date(new simpledateformat("yyyy-mm-dd").parse(req.getparameter("birthday")).gettime()));
teacher.setsalary(new bigdecimal(req.getparameter("salary")));
iteachersservice teacherservice = new teachersserviceimpl();
int rows = teacherservice.save(teacher);
if(rows>0) {
system.out.println("保存一个教师基本信息成功！");
req.getrequestdispatcher("savesuccess.jsp").forward(req, resp);
}
} catch (exception e) {
e.printstacktrace();
system.out.println("添加一个教师对象基本信息的时候失败！");
resp.sendredirect("error.jsp");
}
}
}
一、首先在web.xml文件里面配置相关的信息如下
注： <url-pattern>*.ado</url-pattern> 中的*则代表所选的对应方法
<servlet>
<servlet-name>administratorsservlet</servlet-name>
<servlet-class>cn.gbb.student_achievement_system.controller.administratorsservlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>administratorsservlet</servlet-name>
<url-pattern>*.ado</url-pattern>
</servlet-mapping>
二、在jsp页面中from表单提交的时候需要注意它提交的action里面的内容
注： <form action="<%=request.getcontextpath() %>/saveteacher.ado" method="get">
1 <body style="height: 100%;width: 100%; background-image:url(lib/skr.jpg); background-size: cover;">
2 <div style="height: 100px;width: 100%; text-align: center;">
3 <h1>学生成绩管理系统</h1>
4 </div>
5 <div align="center">
6 <form action="<%=request.getcontextpath() %>/saveteacher.ado" method="get">
7 <%
8 teachers_login teacherlogin = (teachers_login) request.getattribute("teacherlogin");
9 %>
10 <input type="hidden" name="teacherid" value="<%=teacherlogin.getteacherid()%>">
11 <input type="hidden" name="teachername" value="<%=teacherlogin.getteachername()%>">
12 <table>
13 <tr>
14 <th colspan="2" align="center">请填写教师的基本信息</th>
15 </tr>
16 <tr>
17 <td>职工号：</td>
18 <td><%=teacherlogin.getteacherid()%></td>
19 </tr>
20 <tr>
21 <td>姓名：</td>
22 <td><%=teacherlogin.getteachername()%></td>
23 </tr>
24 <tr>
25 <td>性别：</td>
26 <td><input type="text" name="sex"></td>
27 </tr>
28 <tr>
29 <td>电话号码：</td>
30 <td><input type="text" name="phoneno"></td>
31 </tr>
32 <tr>
33 <td>家庭住址：</td>
34 <td><input type="text" name="address"></td>
35 </tr>
36 <tr>
37 <td>出生日期：</td>
38 <td><input type="text" name="birthday"></td>
39 </tr>
40 <tr>
41 <td>工资：</td>
42 <td><input type="text" name="salary"></td>
43 </tr>
44 <tr>
45 <td colspan="2" style="text-align: center;"><input type="submit" value="确定"><input type="reset" value="重置"></td>
46 </tr>
47 </table>
48 </form>
49 <p style="text-align: center;"><a href="administratorsmain.jsp">返回首页</a></p>
50 </div>
51 </body>
总结：这样就可以在jsp页面提交的时候选择servlet里面的所对应的方法了，希望对您有所帮助，谢谢！！！！！