11.11

今天持续更新人口普查系统的相关代码：

今天把所有的dao层代码发出

dbutil连接数据库代码

package dao;
import java.sql.*;
public class DBUtil {
    //eshop为数据库名称，db_user为数据库用户名db_password为数据库密码
    public static String db_url = "jdbc:mysql://localhost:3306/eshop?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT";
    public static String db_user = "root";
    public static String db_password = "root1";

    public static Connection getConn() {
        Connection conn = null;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            conn = DriverManager.getConnection(db_url, db_user, db_password);
            System.out.println("连接成功");
        } catch (Exception e) {
            System.out.println("连接失败");
            e.printStackTrace();
        }
        return 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();
            }
        }
    }
}

接口的代码

package dao;
import java.util.List;
import entity.School;
public interface SchoolDao {
    public boolean add(School school);
    public List<School>select();
    public boolean update(String classname,String classteacher,String classplace);
    public boolean delete(String classname);
    public List<School>selectclassname(String classname);

}

dao层代码

package dao;
import java.sql.*;


import java.util.*;
import entity.School;
public class SchoolDaoImpl implements SchoolDao{
    Connection conn=(Connection)DBUtil.getConn();
    
     public boolean add(School school) {
        
        boolean flag=false;
        PreparedStatement ps=null;
        try {
            //String sql="insert into school values('"+school.getclassname()+"','"+school.getclassteacher()+"','"+school.getclassplace()+"')";
            
            ps=conn.prepareStatement("insert into values2(classname,classteacher,classplace,classnum,zhuname,ID,sex,minzu,education)"+"values (?,?,?,?,?,?,?,?,?)");
            
            ps.setString(1, school.getclassname());
            ps.setString(2, school.getclassteacher());
            ps.setString(3, school.getclassplace());
            ps.setString(4, school.getclassnum());
            ps.setString(5, school.getzhuname());
            ps.setString(6, school.getID());
            ps.setString(7, school.getsex());
            ps.setString(8, school.getminzu());
            ps.setString(9, school.geteducation());
            
            ps.executeUpdate();
            
            ps.close();
            conn.close();
            int i=1;
            if(i>0) {
                flag = true;System.out.println("添加成功");
            }

        }catch(SQLException e) {
            e.printStackTrace();
        }
        return flag;    
    }
        
     
     public List<School> select(){
        List<School> list = new ArrayList<School>();
        try {
            String sql="select * from values2";
            PreparedStatement pstmt = conn.prepareStatement(sql);
            ResultSet rs = pstmt.executeQuery();
            while(rs.next()) {
                School school=new School();
                school.setclassname(rs.getString("classname"));
                school.setclassteacher(rs.getString("classteacher"));
                school.setclassplace(rs.getString("classplace"));
                school.setclassnum(rs.getString("classnum"));
                school.setzhuname(rs.getString("zhuname"));
                school.setID(rs.getString("ID"));
                school.setsex(rs.getString("sex"));
                school.setminzu(rs.getString("minzu"));
                school.seteducation(rs.getString("education"));
                list.add(school);
            }
            rs.close();
            pstmt.close();
            conn.close();

        }catch(SQLException e) {
            e.printStackTrace();
        }
        
        return list;
    }
        
     
     public List<School> showdelete(String zhuname){
        List<School> list = new ArrayList<School>();
        try {
            String sql="select * from values2 where zhuname=?";
            PreparedStatement pstmt = conn.prepareStatement(sql);
            pstmt.setString(1,zhuname);
            ResultSet rs = pstmt.executeQuery();
            while(rs.next()) {
                School school=new School();
                school.setclassname(rs.getString("classname"));
                school.setclassteacher(rs.getString("classteacher"));
                school.setclassplace(rs.getString("classplace"));
                school.setclassnum(rs.getString("classnum"));
                school.setzhuname(rs.getString("zhuname"));
                school.setID(rs.getString("ID"));
                school.setsex(rs.getString("sex"));
                school.setminzu(rs.getString("minzu"));
                school.seteducation(rs.getString("education"));
                list.add(school);
            }
            rs.close();
            pstmt.close();
            conn.close();
        }catch(SQLException e) {
            e.printStackTrace();
        }
        return list;
        
    }

     public List<School> showdelete1(String sex){
            List<School> list = new ArrayList<School>();
            try {
                String sql="select * from values2 where sex=?";
                PreparedStatement pstmt = conn.prepareStatement(sql);
                pstmt.setString(1,sex);
                ResultSet rs = pstmt.executeQuery();
                while(rs.next()) {
                    School school=new School();
                    school.setclassname(rs.getString("classname"));
                    school.setclassteacher(rs.getString("classteacher"));
                    school.setclassplace(rs.getString("classplace"));
                    school.setclassnum(rs.getString("classnum"));
                    school.setzhuname(rs.getString("zhuname"));
                    school.setID(rs.getString("ID"));
                    school.setsex(rs.getString("sex"));
                    school.setminzu(rs.getString("minzu"));
                    school.seteducation(rs.getString("education"));
                    list.add(school);
                }
                rs.close();
                pstmt.close();
                conn.close();
            }catch(SQLException e) {
                e.printStackTrace();
            }
            return list;
            
        }

     
     public List<School> showdelete2(String minzu){
            List<School> list = new ArrayList<School>();
            try {
                String sql="select * from values2 where minzu=?";
                PreparedStatement pstmt = conn.prepareStatement(sql);
                pstmt.setString(1,minzu);
                ResultSet rs = pstmt.executeQuery();
                while(rs.next()) {
                    School school=new School();
                    school.setclassname(rs.getString("classname"));
                    school.setclassteacher(rs.getString("classteacher"));
                    school.setclassplace(rs.getString("classplace"));
                    school.setclassnum(rs.getString("classnum"));
                    school.setzhuname(rs.getString("zhuname"));
                    school.setID(rs.getString("ID"));
                    school.setsex(rs.getString("sex"));
                    school.setminzu(rs.getString("minzu"));
                    school.seteducation(rs.getString("education"));
                    list.add(school);
                }
                rs.close();
                pstmt.close();
                conn.close();
            }catch(SQLException e) {
                e.printStackTrace();
            }
            return list;
            
        }
        
     
     public List<School> showdelete3(String education){
            List<School> list = new ArrayList<School>();
            try {
                String sql="select * from values2 where education=?";
                PreparedStatement pstmt = conn.prepareStatement(sql);
                pstmt.setString(1,education);
                ResultSet rs = pstmt.executeQuery();
                while(rs.next()) {
                    School school=new School();
                    school.setclassname(rs.getString("classname"));
                    school.setclassteacher(rs.getString("classteacher"));
                    school.setclassplace(rs.getString("classplace"));
                    school.setclassnum(rs.getString("classnum"));
                    school.setzhuname(rs.getString("zhuname"));
                    school.setID(rs.getString("ID"));
                    school.setsex(rs.getString("sex"));
                    school.setminzu(rs.getString("minzu"));
                    school.seteducation(rs.getString("education"));
                    list.add(school);
                }
                rs.close();
                pstmt.close();
                conn.close();
            }catch(SQLException e) {
                e.printStackTrace();
            }
            return list;
            
        }
     
     public boolean delete(String zhuname) {
    boolean flag=false;
    try {
        String sql="delete from values2 where zhuname=?";
        PreparedStatement pstmt = conn.prepareStatement(sql);
        pstmt.setString(1,zhuname);
        int i = pstmt.executeUpdate();
        pstmt.close();
        conn.close();
        if(i>0) { flag = true; System.out.println("删除成功！！！");}
    }catch(SQLException e) {
        System.out.println("删除失败");    
        e.printStackTrace();
    }

    return flag;

    }
        
     
     public boolean update(String zhuname,String ID,String sex,String minzu,String education) {
            
                boolean flag=false;
                try {
                    //System.out.println(1471);
                   
                    PreparedStatement pstmt = conn.prepareStatement("update values2 set ID=?,sex=?,minzu=?,education=?where zhuname=?");
                    
                    pstmt.setString(1,ID);
                    pstmt.setString(2,sex);
                    pstmt.setString(3,minzu);
                    
                    pstmt.setString(4,education);
                   
                    pstmt.setString(5,zhuname);
                    //System.out.println(9);
                    int i = pstmt.executeUpdate();
                    System.out.println(159963321);
                    pstmt.close();
                    conn.close();
                    if(i>0) {flag = true;System.out.println("修改成功！！！");}
                }catch(SQLException e) {
               
                    e.printStackTrace();
                }

                return flag;
                
        }
     
    


    @Override
    public List<School> selectclassname(String classname) {
        // TODO 自动生成的方法存根
        return null;
    }


    @Override
    public boolean update(String classname, String classteacher, String classplace) {
        // TODO 自动生成的方法存根
        return false;
    }


    
}