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);
         }
     }
 }