课程管理系统后台JAVA代码

package com.hjf.dao;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import com.hjf.entity.Course;
import com.hjf.util.DBUtil;

/**
 * 课程Dao
 * Dao层操作数据
 * @author Hu
 *
 */
public class CourseDao {

    /**
     * 添加
     * @param course
     * @return
     */
    public boolean add(Course course) {
        String sql = "insert into course(name, sex,minzu,zhuce,age,zhengzhi,fuwu) values('" + course.getName() + "','" + course.getSex() + "','" + course.getMinzu() + "','" + course.getZhuce()+ "','" + course.getAge() + "','" + course.getZhengzhi() + "','" + course.getFuwu()  + "')";
        //创建数据库链接
        Connection conn = DBUtil.getConn();
        Statement state = null;
        boolean f = false;
        int a = 0;
        
        try {
            state = conn.createStatement();
            state.executeUpdate(sql);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            //关闭连接
            DBUtil.close(state, conn);
        }
        
        if (a > 0) {
            f = true;
        }
        return f;
    }

    /**
     * 删除
     * 
     * @param id
     * @return
     */
    public boolean delete (int id) {
        boolean f = false;
        String sql = "delete from course where id='" + id + "'";
        
        Connection conn = DBUtil.getConn();
        Statement state = null;
        int a = 0;
        
        try {
            state = conn.createStatement();
            a = state.executeUpdate(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(state, conn);
        }
        
        if (a > 0) {
            f = true;
        }
        return f;
    }

    /**
     * 修改
     * @param name
     * @param pass
     */
    public boolean update(Course course) {
        String sql = "update course set name='" + course.getName() + "', sex='" + course.getSex() + "', minzu='" + course.getMinzu()+ "', zhuce='" + course.getZhuce()+ "', age='" + course.getAge()+ "', zhengzhi='" + course.getZhengzhi()+ "', fuwu='" + course.getFuwu()
            + "' where id='" + course.getId() + "'";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        boolean f = false;
        int a = 0;

        try {
            state = conn.createStatement();
            a = state.executeUpdate(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(state, conn);
        }
        
        if (a > 0) {
            f = true;
        }
        return f;
    }
    
    /**
     * 验证课程名称是否唯一
     * true --- 不唯一
     * @param name
     * @return
     */
    public boolean name(String name) {
        boolean flag = false;
        String sql = "select name from course where name = '" + name + "'";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;
        
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
                flag = true;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        return flag;
    }
    
    /**
     * 通过ID得到课程信息
     * @param id
     * @return
     */
    public Course getCourseById(int id) {
        String sql = "select * from course where id ='" + id + "'";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;
        Course course = null;
        
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
                String name = rs.getString("name");
                String sex = rs.getString("sex");
                String minzu = rs.getString("minzu");
                String zhuce = rs.getString("zhuce");
                String age = rs.getString("age");
                String zhengzhi = rs.getString("zhengzhi");
                String fuwu = rs.getString("fuwu");
                
                course = new Course(id, name, sex, minzu,zhuce,age,zhengzhi,fuwu);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        
        return course;
    }
    
    /**
     * 通过name得到Course
     * @param name
     * @return
     */
    public Course getCourseByName(String name) {
        String sql = "select * from course where name ='" + name + "'";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;
        Course course = null;
        
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
                int id = rs.getInt("id");
                
                String sex = rs.getString("sex");
                String minzu = rs.getString("minzu");
                String zhuce = rs.getString("zhuce");
                String age = rs.getString("age");
                String zhengzhi = rs.getString("zhengzhi");
                String fuwu = rs.getString("fuwu");
                
                course = new Course(id, name, sex, minzu,zhuce,age,zhengzhi,fuwu);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        
        return course;
    }
    
    /**
     * 查找
     * @param name
     * @param teacher
     * @param classroom
     * @return
     */
    public List<Course> search(String name, String sex, String minzu, String zhuce, String age, String zhengzhi, String fuwu) {
        String sql = "select * from course where ";
        if (name != ""&&sex !=""&&minzu!=""&&zhuce!=""&&age!=""&&zhengzhi!=""&&fuwu!="") {
            sql += "name like '%" + name + "%'&&sex like '%" + sex + "%'&&minzu like '%" + minzu + "%'&&zhuce like '%" + zhuce + "%'&&age like '%" + age + "%'&&zhengzhi like '%" + zhengzhi + "%'&&fuwu like '%" + fuwu + "%'";
        }
        if (sex != "") {
            sql += "sex like '%" + sex + "%'";
        }
        if (minzu != "") {
            sql += "minzu like '%" + minzu + "%'";
        }
        if (zhuce != "") {
            sql += "zhuce like '%" + zhuce + "%'";
        }
        if (age != "") {
            sql += "age like '%" + age + "%'";
        }
        if (zhengzhi != "") {
            sql += "zhengzhi like '%" + zhengzhi + "%'";
        }
        if (fuwu != "") {
            sql += "fuwu like '%" + fuwu + "%'";
        }
        List<Course> list = new ArrayList<>();
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;

        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            Course bean = null;
            while (rs.next()) {
                int id = rs.getInt("id");
                String name2 = rs.getString("name");
                String sex2 = rs.getString("sex");
                String minzu2 = rs.getString("minzu");
                String zhuce2 = rs.getString("zhuce");
                String age2 = rs.getString("age");
                String zhengzhi2 = rs.getString("zhengzhi");
                String fuwu2 = rs.getString("fuwu");
                
                bean = new Course(id, name2, sex2, minzu2,zhuce2,age2,zhengzhi2,fuwu2);
                list.add(bean);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        
        return list;
    }
    
    /**
     * 全部数据
     * @param name
     * @param teacher
     * @param classroom
     * @return
     */
    public List<Course> list() {
        String sql = "select * from course";
        List<Course> list = new ArrayList<>();
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;

        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            Course bean = null;
            while (rs.next()) {
                int id = rs.getInt("id");
                String name2 = rs.getString("name");
                String sex2 = rs.getString("sex");
                String minzu2 = rs.getString("minzu");
                String zhuce2 = rs.getString("zhuce");
                String age2 = rs.getString("age");
                String zhengzhi2 = rs.getString("zhengzhi");
                String fuwu2 = rs.getString("fuwu");
                
                bean = new Course(id, name2, sex2, minzu2,zhuce2,age2,zhengzhi2,fuwu2);
                list.add(bean);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        
        return list;
    }

}
package com.hjf.entity;

public class Course {

    private int id;
    private String name;
    private String sex;
    private String minzu;
    private String zhuce;
    private String age;
    private String zhengzhi;
    private String fuwu;
    
    
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public String getMinzu() {
        return minzu;
    }
    public void setMinzu(String minzu) {
        this.minzu = minzu;
    }
    public String getZhuce() {
        return zhuce;
    }
    public void setZhuce(String zhuce) {
        this.zhuce = zhuce;
    }
    public String getAge() {
        return age;
    }
    public void setAge(String age) {
        this.age = age;
    }
    public String getZhengzhi() {
        return zhengzhi;
    }
    public void setZhengzhi(String zhengzhi) {
        this.zhengzhi = zhengzhi;
    }
    public String getFuwu() {
        return fuwu;
    }
    public void setFuwu(String fuwu) {
        this.fuwu = fuwu;
    }
    public Course() {}
    
    public Course(int id, String name, String sex, String minzu,String zhuce, String age, String zhengzhi,String fuwu) {
        this.id = id;
        this.name = name;
        this.sex = sex;
        this.minzu = minzu;
        this.zhuce = zhuce;
        this.age = age;
        this.zhengzhi = zhengzhi;
        this.fuwu = fuwu;
        
    }
    
    public Course(String name, String sex, String minzu,String zhuce, String age, String zhengzhi,String fuwu) {
        this.name = name;
        this.sex = sex;
        this.minzu = minzu;
        this.zhuce = zhuce;
        this.age = age;
        this.zhengzhi = zhengzhi;
        this.fuwu = fuwu;
    }
}
package com.hjf.service;

import java.util.List;

import com.hjf.dao.CourseDao;
import com.hjf.entity.Course;

/**
 * CourseService
 * 服务层
 * @author Hu
 *
 */
public class CourseService {

    CourseDao cDao = new CourseDao();
    
    /**
     * 添加
     * @param course
     * @return
     */
    public boolean add(Course course) {
        boolean f = false;
        if(!cDao.name(course.getName())) {
            cDao.add(course);
            f = true;
        }
        return f;
    }
    
    /**
     * 删除
     */
    public void del(int id) {
        cDao.delete(id);
    }
    
    /**
     * 修改
     * @return 
     */
    public void update(Course course) {
        cDao.update(course);
    }
    
    /**
     * 通过ID得到一个Course
     * @return 
     */
    public Course getCourseById(int id) {
        return cDao.getCourseById(id);
    }

    /**
     * 通过Name得到一个Course
     * @return 
     */
    public Course getCourseByName(String name) {
        return cDao.getCourseByName(name);
    }
    
    /**
     * 查找
     * @return 
     */
    public List<Course> search(String name, String sex, String minzu,String zhuce, String age, String zhengzhi,String fuwu) {
        return cDao.search( name, sex, minzu,zhuce, age, zhengzhi,fuwu);
    }
    
    /**
     * 全部数据
     * @return 
     */
    public List<Course> list() {
        return cDao.list();
    }
}
package com.hjf.servlet;

import java.io.IOException;
import java.util.List;

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 com.hjf.entity.Course;
import com.hjf.service.CourseService;

@WebServlet("/CourseServlet")
public class CourseServlet extends HttpServlet {
    
    private static final long serialVersionUID = 1L;

    CourseService service = new CourseService();
    
    /**
     * 方法选择
     */
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        String method = req.getParameter("method");
        
        if ("add".equals(method)) {
            add(req, resp);
        } else if ("del".equals(method)) {
            del(req, resp);
        } else if ("update".equals(method)) {
            update(req, resp);
        } else if ("search".equals(method)) {
            search(req, resp);
        } else if ("getcoursebyid".equals(method)) {
            getCourseById(req, resp);
        } else if ("getcoursebyname".equals(method)) {
            getCourseByName(req, resp);
        } else if ("list".equals(method)) {
            list(req, resp);
        }
    }

    /**
     * 添加
     * @param req
     * @param resp
     * @throws IOException 
     * @throws ServletException 
     */
    private void add(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
        req.setCharacterEncoding("utf-8");
        //获取数据
        String name = req.getParameter("name");
        String sex = req.getParameter("sex");
        String minzu = req.getParameter("minzu");
        String zhuce = req.getParameter("zhuce");
        String age = req.getParameter("age");
        String zhengzhi = req.getParameter("zhengzhi");
        String fuwu = req.getParameter("fuwu");
        Course course = new Course(name, sex, minzu,zhuce, age, zhengzhi,fuwu);
        
        //添加后消息显示
        if(service.add(course)) {
            req.setAttribute("message", "添加成功");
            req.getRequestDispatcher("add.jsp").forward(req,resp);
        } else {
            req.setAttribute("message", "课程名称重复，请重新录入");
            req.getRequestDispatcher("add.jsp").forward(req,resp);
        }
    }
    
    /**
     * 全部
     * @param req
     * @param resp
     * @throws ServletException 
     */
    private void list(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
        req.setCharacterEncoding("utf-8");
        
        List<Course> courses = service.list();
        req.setAttribute("courses", courses);
        req.getRequestDispatcher("list.jsp").forward(req,resp);
    }

    /**
     * 通过ID得到Course
     * @param req
     * @param resp
     * @throws ServletException 
     */
    private void getCourseById(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
        req.setCharacterEncoding("utf-8");
        int id = Integer.parseInt(req.getParameter("id"));
        Course course = service.getCourseById(id);
        req.setAttribute("course", course);
        req.getRequestDispatcher("detail2.jsp").forward(req,resp);
    }

    /**
     * 通过名字查找
     * 跳转至删除
     * @param req
     * @param resp
     * @throws IOException
     * @throws ServletException 
     */
    private void getCourseByName(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
        req.setCharacterEncoding("utf-8");
        String name = req.getParameter("name");
        Course course = service.getCourseByName(name);
        if(course == null) {
            req.setAttribute("message", "查无此课程！");
            req.getRequestDispatcher("del.jsp").forward(req,resp);
        } else {
            req.setAttribute("course", course);
            req.getRequestDispatcher("detail.jsp").forward(req,resp);
        }
    }
    
    /**
     * 删除
     * @param req
     * @param resp
     * @throws IOException
     * @throws ServletException 
     */
    private void del(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
        req.setCharacterEncoding("utf-8");
        int id = Integer.parseInt(req.getParameter("id"));
        service.del(id);
        req.setAttribute("message", "删除成功！");
        req.getRequestDispatcher("del.jsp").forward(req,resp);
    }
    
    /**
     * 修改
     * @param req
     * @param resp
     * @throws IOException
     * @throws ServletException 
     */
    private void update(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
        req.setCharacterEncoding("utf-8");
        int id = Integer.parseInt(req.getParameter("id"));
        String name = req.getParameter("name");
        String sex = req.getParameter("sex");
        String minzu = req.getParameter("minzu");
        String zhuce = req.getParameter("zhuce");
        String age = req.getParameter("age");
        String zhengzhi = req.getParameter("zhengzhi");
        String fuwu = req.getParameter("fuwu");
        Course course = new Course(id,name, sex, minzu,zhuce, age, zhengzhi,fuwu);
        
        
        service.update(course);
        req.setAttribute("message", "修改成功");
        req.getRequestDispatcher("CourseServlet?method=list").forward(req,resp);
    }
    
    /**
     * 查找
     * @param req
     * @param resp
     * @throws ServletException 
     */
    private void search(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
        req.setCharacterEncoding("utf-8");
        String name = req.getParameter("name");
        String sex = req.getParameter("sex");
        String minzu = req.getParameter("minzu");
        String zhuce = req.getParameter("zhuce");
        String age = req.getParameter("age");
        String zhengzhi = req.getParameter("zhengzhi");
        String fuwu = req.getParameter("fuwu");
        List<Course> courses = service.search(name, sex, minzu,zhuce, age, zhengzhi,fuwu);
        req.setAttribute("courses", courses);
        req.getRequestDispatcher("searchlist.jsp").forward(req,resp);
    }
}
package com.hjf.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * 数据库连接工具
 * @author Hu
 *
 */
public class DBUtil {
    
    public static String db_url = "jdbc:mysql://localhost:3306/user";
    public static String db_user = "root";
    public static String db_pass = "root";
    
    public static Connection getConn () {
        Connection conn = null;
        
        try {
            Class.forName("com.mysql.jdbc.Driver");//加载驱动
            conn = DriverManager.getConnection(db_url, db_user, db_pass);
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        return conn;
    }
    
    /**
     * 关闭连接
     * @param state
     * @param conn
     */
    public static void close (Statement state, Connection conn) {
        if (state != null) {
            try {
                state.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
    
    public static void close (ResultSet rs, Statement state, Connection conn) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        
        if (state != null) {
            try {
                state.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void main(String[] args) throws SQLException {
        Connection conn = getConn();
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        String sql ="select * from course";
        pstmt = conn.prepareStatement(sql);
        rs = pstmt.executeQuery();
        if(rs.next()){
            System.out.println("空");
        }else{
            System.out.println("不空");
        }
    }
}