一些servlet的代码
- 添加数据
@WebServlet(name = "AddServlet", value = "/AddServlet")
public class AddServlet extends HttpServlet {
StudentService studentService = new StudentService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
// 获取请求体数据
BufferedReader br = request.getReader();
// 不管参数多长都只有一行
String s = br.readLine();
System.out.println(s);
// 转换成java对象
Student student = JSON.parseObject(s, Student.class);
System.out.println(student);
// 调用service添加
studentService.addStudent(student);
// 写入成功
response.getWriter().write("success");
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request,response);
}
}
- 查询数据(所有)
@WebServlet(name = "SelectAllServlet", value = "/SelectAllServlet")
public class SelectAllServlet extends HttpServlet {
StudentService studentService = new StudentService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
List<Student> students = studentService.selectAll();
// 将集合转换成字符串
String s = JSON.toJSONString(students);
// 响应
response.setContentType("text/json;charset=utf-8");
response.getWriter().write(s);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request,response);
}
}
- 查询数据(条件查询)
@WebServlet(name = "SelectByIdServlet", value = "/SelectByIdServlet")
public class SelectByIdServlet extends HttpServlet {
StudentService studentService = new StudentService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 设置编码方式
request.setCharacterEncoding("UTF-8");
// 获取请求流
BufferedReader reader = request.getReader();
// 获取请求数据
String par = reader.readLine();
System.out.println(par);
// 将请求数据转成java对象
Student st = JSON.parseObject(par, Student.class);
System.out.println(st);
// 执行sql
Student student = studentService.selectBy(st);
System.out.println(student);
// 将返回的数据转成字符串
String s = JSON.toJSONString(student);
response.setContentType("text/json;charset=utf-8");
// 写入response
response.getWriter().write(s);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request,response);
}
}