0402数据放入集合进行查询-Java(新手)

 

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JDBC工具类：

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package cn.Wuchang.zyDome;

import java.sql.*;

public class JDBCUtils {
    private static final String r = "root";
    private static final String p = "root";
    private static final String url = "jdbc:mysql:///semployee";
    private static final String DRIVER = "com.mysql.jdbc.Driver";
    //注册驱动。
    static{
        try {
            Class.forName(DRIVER);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    //得到数据库链接。
    public static Connection getConnection() throws Exception {
        return DriverManager.getConnection(url,r,p);

    }
    //关闭链接，执行打开的资源。
    public static void close(Connection conn,Statement stmt){
        if (stmt!=null){
            try {
                stmt.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        if (conn!=null){
            try {
                conn.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    //关闭所有打开的资源。
    public static void close(Connection conn, Statement stmt, ResultSet rs){
        if (stmt!=null){
            try {
                stmt.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }if (conn!=null){
            try {
                conn.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        if (rs!=null){
            try {
                rs.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

}

 

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创建实体类：

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package cn.Wuchang.zyDome;

import java.math.BigDecimal;

public class GetDome1 {
    //创建变量。
    private int uid;
    private String uname;
    private  int Job_id;
    private  int mgr;
    private  String state;
    private  double salary;
    private  double bonus;
    private  int Dept_id;

    //创建有参构造。
    public GetDome1(int uid, String uname, int job_id, int mgr, String state, double salary, double bonus, int dept_id) {
        this.uid = uid;
        this.uname = uname;
        Job_id = job_id;
        this.mgr = mgr;
        this.state = state;
        this.salary = salary;
        this.bonus = bonus;
        Dept_id = dept_id;
    }
    //创建GetSet方法。
    public int getUid() {
        return uid;
    }

    public void setUid(int uid) {
        this.uid = uid;
    }

    public String getUname() {
        return uname;
    }

    public void setUname(String uname) {
        this.uname = uname;
    }

    public int getJob_id() {
        return Job_id;
    }

    public void setJob_id(int job_id) {
        Job_id = job_id;
    }

    public int getMgr() {
        return mgr;
    }

    public void setMgr(int mgr) {
        this.mgr = mgr;
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }

    public double getSalary() {
        return salary;
    }

    public void setSalary(double salary) {
        this.salary = salary;
    }

    public double getBonus() {
        return bonus;
    }

    public void setBonus(double bonus) {
        this.bonus = bonus;
    }

    public int getDept_id() {
        return Dept_id;
    }

    public void setDept_id(int dept_id) {
        Dept_id = dept_id;
    }
    //创建toString方法。
    @Override
    public String toString() {
        return "GetDome1{" +
                "uid=" + uid +
                ", uname='" + uname + '\'' +
                ", Job_id=" + Job_id +
                ", mgr=" + mgr +
                ", state='" + state + '\'' +
                ", salary=" + salary +
                ", bonus=" + bonus +
                ", Dept_id=" + Dept_id +
                '}';
    }
}

 

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把数据放到集合中并且查询出来：

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package cn.Wuchang.zyDome;

import java.sql.*;
import java.util.*;

public class zyDome1 {
    public static void main(String[] args) throws Exception {
        fun1();
    }
    public static void fun1(){

        List<GetDome1> list=new ArrayList<GetDome1>();
        Connection conn = null;
        PreparedStatement ppst = null;
        ResultSet rs = null;
        try {
            //获取数据库链接。
            conn = JDBCUtils.getConnection();
            //获取对象执行SQL语句。
            ppst = conn.prepareStatement("select * from emp");
            //执行查询。
            rs = ppst.executeQuery();
            while (rs.next()){
                //添加对象。
                list.add(new GetDome1(
                                rs.getInt("uid"),
                                rs.getString("uname"),
                                rs.getInt("Job_id"),
                                rs.getInt("mgr"),
                                rs.getString("state"),
                                rs.getDouble("salary"),
                                rs.getDouble("bonus"),
                                rs.getInt("Dept_id")));

            }
            for(GetDome1 g:list){
                System.out.println(g.toString());
            }


        } catch (Exception e) {
            e.printStackTrace();
        }
        finally {
            JDBCUtils.close(conn,ppst,rs);
        }
    }
}