jdbk应用实例

首先要在数据库中建好表，表的属性要跟代码中的一致

使用jdbk连接数据库，并且进行增删改查的操作(curd).

 package com.beiwi;

 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.util.ResourceBundle;

 import java.sql.ResultSet;
 import java.sql.Statement;

 /**
  *    数据库的帮助类
  * @author Lrs
  *
  */
 public class DBUtils {

     private static String driverClass;
     private static String url;
     private static String user;
     private static String password;

     static{
         ResourceBundle rb = ResourceBundle.getBundle("jdbc");
         driverClass = rb.getString("driverClass");
         url = rb.getString("url");
         user = rb.getString("user");
         password = rb.getString("password");

         try {
             Class.forName(driverClass);
         } catch (ClassNotFoundException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }

     public static Connection getConn() throws Exception{
         return DriverManager.getConnection(url, user, password);
     }

     public static void closeAll(ResultSet rs,Statement stmt,Connection conn){

         if(null!=rs){
             try {
                 rs.close();
             } catch (Exception e) {
                 e.printStackTrace();
             }
         }
         if(null!=stmt){
             try {
                 stmt.close();
             } catch (Exception e) {
                 e.printStackTrace();
             }
         }

         if(null!=conn){
             try {
                 conn.close();
             } catch (Exception e) {
                 e.printStackTrace();
             }
         }
     }

 }

 package com.beiwi;

 import java.sql.Connection;

 import java.sql.ResultSet;
 import java.sql.Statement;

 /**
  * 增删改查操作的方法
  *  create:新增
  *  refer:查询
  *  update：更新
  *  delete：删除
  * @author Lrs
  *
  */
 public class MasterCurd {

     /**
      * 查询所有主人的信息
      */
     public void findAll(){
         String sql = "SELECT * FROM master";
         Connection conn = null;
         Statement stmt = null;
         ResultSet rs = null;

         try {
             conn = DBUtils.getConn();
             stmt = conn.createStatement();
             rs = stmt.executeQuery(sql);

             while (rs.next()) {
                 System.out.println(rs.getObject(1));
                 System.out.println(rs.getObject(2));
                 System.out.println(rs.getObject(3));
                 System.out.println(rs.getObject(4));
                 System.out.println("**************************");
             }
         } catch (Exception e) {
             e.printStackTrace();
         }finally{
             DBUtils.closeAll(rs, stmt, conn);
         }

     }
     /**
      *  insert一条记录
      */

     public void insert(){
         String sql = "INSERT INTO master (id,user,password,money) VALUES ('4','haha','456','100');";

         Connection conn = null;
         Statement stmt = null;

         try {
             conn = DBUtils.getConn();
             stmt = conn.createStatement();
             stmt.executeUpdate(sql);
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             DBUtils.closeAll(null, stmt, conn);
         }
     }

     /**
      * 更新一条记录
      */
     public void update(){
         String sql = "UPDATE master SET user='beiwo1',password='456',money=888 WHERE id=1";
         Connection conn = null;
         Statement stmt = null;

         try {
             conn = DBUtils.getConn();
             stmt = conn.createStatement();
             int num = stmt.executeUpdate(sql);

             if (num>0) {
                 System.out.println("更新成功");
             }

         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             DBUtils.closeAll(null, stmt, conn);
         }
     }
     /**
      * 删除一条记录
      */
     public void delete(){
         String sql = "DELETE FROM master WHERE id=3";
         Connection  conn = null;
         Statement stmt = null;

         try {
             conn = DBUtils.getConn();
             stmt = conn.createStatement();
             int num = stmt.executeUpdate(sql);

             if (num > 0) {
                 System.out.println("删除成功");
             }
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             DBUtils.closeAll(null, stmt, conn);
         }
     }
 }

 package com.beiwi;

 import org.junit.Before;
 import org.junit.Test;

 /**
  *  测试类
  */

 public class TestMasterCrud {

     MasterCurd curd = null;

     @Before
     public void before(){
         curd = new MasterCurd();
     }
     @Test
     public void testFindAll(){
         curd.findAll();
     }
     @Test
     public void testInsert(){
         curd.insert();
     }
     @Test
     public void testUpdate(){
         curd.update();
     }
     @Test
     public void testDelete(){
         curd.delete();
     }
     @Test
     public void after(){
         curd=null;
     }

 }