利用Java web学生增删改查的serlvet类
import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map;
import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;
@WebServlet("/student") public class StudentServlet extends HttpServlet { private static final long serialVersionUID = 1L;
private Map<Integer, Student> studentMap;
private int studentIdCounter;
public void init() {
studentMap = new HashMap<>();
studentIdCounter = 1;
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html><head><title>Student List</title></head><body>");
out.println("<h1>Student List</h1>");
out.println("<table border='1'>");
out.println("<tr><th>ID</th><th>Name</th><th>Age</th><th>Action</th></tr>");
for (Student student : studentMap.values()) {
out.println("<tr>");
out.println("<td>" + student.getId() + "</td>");
out.println("<td>" + student.getName() + "</td>");
out.println("<td>" + student.getAge() + "</td>");
out.println("<td><a href='/student?action=delete&id=" + student.getId() + "'>Delete</a></td>");
out.println("</tr>");
}
out.println("</table>");
out.println("<br>");
out.println("<form action='/student' method='post'>");
out.println("Name: <input type='text' name='name'><br>");
out.println("Age: <input type='text' name='age'><br>");
out.println("<input type='submit' value='Add Student'>");
out.println("</form>");
out.println("</body></html>");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String action = request.getParameter("action");
if (action != null && action.equals("delete")) {
int id = Integer.parseInt(request.getParameter("id"));
studentMap.remove(id);
} else {
String name = request.getParameter("name");
int age = Integer.parseInt(request.getParameter("age"));
Student student = new Student(studentIdCounter++, name, age);
studentMap.put(student.getId(), student);
}
response.sendRedirect("/student");
}
}
class Student { private int id; private String name; private int age;
public Student(int id, String name, int age) {
this.id = id;
this.name = name;
this.age = age;
}
public int getId() {
return id;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
}
原文地址: https://www.cveoy.top/t/topic/i4TA 著作权归作者所有。请勿转载和采集!