import com.alibaba.fastjson.JSONObject;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*;
import java.util.*;
import java.util.Date;@WebServlet("/hello")//注解，免于在xml注册，/hello表示在主页后加/hello访问此页面
public class test extends HttpServlet {private String message;public void init() throws ServletException{}public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {//相应不带参数的getString dbURL="jdbc:sqlserver://127.0.0.1:1433;DatabaseName=S-T";String userName="sa";String userPwd="111";String sql="select * from Student";List<student> students=new ArrayList<>();Connection dbConn=null;try {String driverName="com.microsoft.sqlserver.jdbc.SQLServerDriver";Class.forName(driverName);//反射JDBC包，这个一定要加，不然会报错// 设置响应内容类型response.setContentType("text/html");response.setCharacterEncoding("UTF-8");dbConn= DriverManager.getConnection(dbURL,userName,userPwd);Statement statement=dbConn.createStatement();ResultSet resultSet=statement.executeQuery(sql);while (resultSet.next()){student st=new student();st.setName(resultSet.getString("Sname"));st.setId(resultSet.getString("Sno"));st.setSex(resultSet.getString("Ssex"));st.setAge(resultSet.getString("Sage"));students.add(st);}response.getWriter().println(JSONObject.toJSONString(students));//注意这里不是控制台输出了，是HttpServletResponse，用于返回json给http请求方//out.println(JSONObject.toJSONString(resultSet));} catch (SQLException e) {e.printStackTrace();} catch (ClassNotFoundException e) {e.printStackTrace();}finally {try{//关闭连接if(dbConn!=null){dbConn.close();dbConn=null;}}catch(Exception ex){}}}
}