1、原生jdbc连接oracle数据库简单介绍

一。jbdc的常用API
1.Connection:数据库的链接对象
2.statement:数据库sql执行对象
3.preparedStatment：sql的预编译处理对象，是statement子接口
4.resultset：返回查询的结果集

二。jdbc开发步骤
1.在项目中加入驱动jar包
2.写jdbc链接代码
注意：日期对象的处理。从结果集中获取时间是用getTimestamp(),得到的是Timestamp对象（时间戳）
Timestamp是util.Date的子类。他们之间的互相转换是：
util.Date = Timestamp直接转换
Timestamp = new TimeStamp(util.Date.getTime());

三。工厂模式
1.工厂类，专门用来生产某一个对象的实例

四。preparedStatment 预编译sql命令接口
1.会对sql语句进行编译检查，可以用参数占位符的方式编写sql语句
2.作用：比普通statement接口执行效率更高。可以防止sql注入的侵入

　　SQL实例：

 drop table user_info;
 drop table group_info;
 drop table contacts_info;

 select * from user_info
 select * from group_info
 select * from contacts_info

 delete from user_info;
 delete from group_info;

 --创建用户信息表
 create table user_info(
     user_id int identity(1,1) primary key,
     user_name nvarchar(30) unique not null,
     user_password nvarchar(30) not null
     )

 --创建联系人群组信息表
 create table group_info(
     group_id int identity(1,1) primary key,
     group_name nvarchar(30),
     group_state nchar(3) default '可修改',
     check(group_state in ('可修改','不可改')),
     user_id int,
     foreign key (user_id) references user_info(user_id)
     )

 --创建联系人信息表
 create table contacts_info(
     con_id int identity(1,1) primary key,
     con_name nvarchar(30) not null,
     con_sex nchar(1) default '男',
     check(con_sex in ('男','女')),
     con_age int,
     con_cellphone nvarchar(30),
     con_telephone nvarchar(30),
     con_birth datetime,
     con_email nvarchar(30),
     con_static nchar(3) default '未删除',
     check(con_static in ('未删除','已删除')),
     group_id int,
     foreign key (group_id) references group_info(group_id)
     )

java实例1：创建jdbc工厂类

　　jdbc.properties

jdbc.driver=oracle.jdbc.driver.OracleDriver
jdbc.url=jdbc:oracle:thin:@localhost:1521:orcl
jdbc.username=C##java06
jdbc.password=java123

JDBCFactory.java类

 package com.demo1207;

 import java.io.IOException;
 import java.io.InputStream;
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.Properties;

 public class JDBCFactory {
  //    private static final String DRIVER = "oracle.jdbc.driver.OracleDriver";
 //    private static final String URL = "jdbc:oracle:thin:@localhost:1521:orcl";
 //    private static final String USERNAME = "C##java06";
 //    private static final String PASSWORD = "java123";

     static String DRIVER;
     static String URL;
     static String USERNAME;
     static String PASSWORD;
     static{
         //只会在类第一次加载时被执行一次，适合做资源文件的读取
         //加载数据库配置文件资源
         Properties pro = new Properties();
         //把资源读取成字节输入流
         InputStream is = JDBCFactory.class.getResourceAsStream("jdbc.properties");

         try {
             //通过资源对象加载字节输入流
             pro.load(is);
             //资源对象通过key来获取对应的文件中的值，注意：静态代码块只能使用静态属性
             DRIVER = pro.getProperty("jdbc.driver");
             URL = pro.getProperty("jdbc.url");
             USERNAME = pro.getProperty("jdbc.username");
             PASSWORD = pro.getProperty("jdbc.password");
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }

     /**
      * 获取数据库链接
      * @return 如果有异常则会返回null
      */
     public static Connection getConn(){
         Connection conn = null;
         try {
             Class.forName(DRIVER);
             conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
         } catch (Exception e) {
             e.printStackTrace();
         }
         return conn;
     }

     public static void closeAll(Connection conn,Statement st,ResultSet rs){
         if(conn!=null){
             try {
                 conn.close();
             } catch (SQLException e) {
                 e.printStackTrace();
             }
         }
         if(st!=null){
             try {
                 st.close();
             } catch (SQLException e) {
                 e.printStackTrace();
             }
         }
         if(rs!=null){
             try {
                 rs.close();
             } catch (SQLException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             }
         }
     }
 }

java实例2:调用工厂类

在java类中写一个Student对象，用来封装学员信息
查询学员信息表，将结果集封装到List<Student>
提示：学员对象的时间字段用util.Date. 每个属性都要封装

　　Student.java

 package com.demo1207;

 import java.util.Date;

 public class Student {
     private int student_id;
     private String student_name;
     private String student_sex;
     private int student_age;
     private int class_id;
     private Date birthday;
     public int getStudent_id() {
         return student_id;
     }
     public void setStudent_id(int student_id) {
         this.student_id = student_id;
     }
     public String getStudent_name() {
         return student_name;
     }
     public void setStudent_name(String student_name) {
         this.student_name = student_name;
     }
     public String getStudent_sex() {
         return student_sex;
     }
     public void setStudent_sex(String student_sex) {
         this.student_sex = student_sex;
     }
     public int getStudent_age() {
         return student_age;
     }
     public void setStudent_age(int student_age) {
         this.student_age = student_age;
     }
     public int getClass_id() {
         return class_id;
     }
     public void setClass_id(int class_id) {
         this.class_id = class_id;
     }
     public Date getBirthday() {
         return birthday;
     }
     public void setBirthday(Date birthday) {
         this.birthday = birthday;
     }

 }

　　JdbcTest.java

 package com.demo1207;

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

 public class JdbcTest {
     public static void main(String[] args) {
         Connection conn = null;
         Statement st = null;
         ResultSet rs = null;
         try {
             conn = JDBCFactory.getConn();
             System.out.println(conn);

             //处理sql命令的对象
             st = conn.createStatement();

             String sql = "insert into student_info values(sq_student.nextval,'叶挺',1,22,1,sysdate)";
             //st来执行sql语句，注意executeUpdate是执行增删改的语句
             st.executeUpdate(sql);

             //执行查询业务
             String sql2 = "select * from student_info";
             rs = st.executeQuery(sql2);
             List<Student> list = new ArrayList<>();
             while(rs.next()){
                 Student stu = new Student();
                 stu.setStudent_id(rs.getInt(1));
                 stu.setStudent_name(rs.getString(2));
                 stu.setStudent_sex(rs.getString(3));
                 stu.setStudent_age(rs.getInt(4));
                 stu.setClass_id(rs.getInt(5));
                 stu.setBirthday(rs.getTimestamp(6));
                 list.add(stu);
                 System.out.print(rs.getInt(1)+"\t");
                 System.out.print(rs.getString("student_name")+"\t");
                 System.out.print(rs.getString(3)+"\t");
                 System.out.print(rs.getInt(4)+"\t");
                 System.out.print(rs.getInt(5)+"\t");
                 System.out.println(rs.getTimestamp(6));
             }
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             JDBCFactory.closeAll(conn, st, rs);
         }
     }
 }

java实例3：调用jdbc工厂类来验证登录

PreparedDemo.java

 package com.demo1207;

 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;

 public class PreparedDemo {
     public static void main(String[] args) {
         Connection conn = null;
         PreparedStatement ps = null;
         ResultSet rs = null;

         try {
             conn = JDBCFactory.getConn();
             String sql = "select * from user_info where username=? and pass_word=?";
             ps = conn.prepareStatement(sql);
             //将参数占位符赋值
             ps.setString(1, "张三");
             ps.setString(2, "123456");

             //执行sql 和statement的执行方法一样
             rs = ps.executeQuery();
             if(rs.next()){
                 System.out.println(rs.getString(2)+"登录成功");
             }else{
                 System.out.println("登录失败");
             }
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             JDBCFactory.closeAll(conn, ps, rs);
         }
     }
 }

java实例4：调用工厂类进行增删改查

 package com.demo1207;

 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.Timestamp;
 import java.util.Date;

 public class CRUDDemo {
     Connection conn;
     PreparedStatement ps;
     ResultSet rs;

     public  void create(){
         try {
             conn = JDBCFactory.getConn();

             String sql = "insert into student_info values(sq_student.nextval,?,?,?,?,?)";
             ps = conn.prepareStatement(sql);

             ps.setString(1, "田甜");
             ps.setString(2, "2");
             ps.setInt(3, 22);
             ps.setInt(4, 1);
             ps.setTimestamp(5, new Timestamp(new Date().getTime()));
             ps.executeUpdate();
             System.out.println("新增成功");
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             JDBCFactory.closeAll(conn, ps, rs);
         }
     }

     public void delete(){
         try {
             conn = JDBCFactory.getConn();

             String sql = "delete from student_info where student_id=?";
             ps = conn.prepareStatement(sql);

             ps.setInt(1, 1);
             ps.executeUpdate();
             System.out.println("删除成功");
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             JDBCFactory.closeAll(conn, ps, rs);
         }
     }

     public void update(){
         try {
             conn = JDBCFactory.getConn();

             String sql = "update student_info set student_name=?,student_sex=?,student_age=?,class_id=?,birthday=? where student_id=?";
             ps = conn.prepareStatement(sql);

             ps.setString(1, "哈哈");
             ps.setString(2, "2");
             ps.setInt(3, 28);
             ps.setInt(4, 1);
             ps.setTimestamp(5, new Timestamp(new Date().getTime()));
             ps.setInt(6, 2);
             ps.executeUpdate();
             System.out.println("修改成功");
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             JDBCFactory.closeAll(conn, ps, rs);
         }
     }

     public void query(){
         try {
             conn = JDBCFactory.getConn();

             String sql = "select * from student_info";
             ps = conn.prepareStatement(sql);

             rs = ps.executeQuery();
             while(rs.next()){
                 System.out.println();
             }
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             JDBCFactory.closeAll(conn, ps, rs);
         }
     }
 }

作业：

一。用户管理
1.用户注册：要求用户名不能重复
2.用户登录
二。联系人组群管理
1.用户新建联系人组群：每个用户注册时都会默认新建一个名字叫“我的联系人”这么一个组群，该组群不能修改，
                每个用户可以新建n个联系人组群。
2.用户修改联系组群：修改组群名字
3.用户删除组群：删除组群后，将该组的所有联系人移到默认组群“我的联系人”
三。联系人管理
1.用户新建联系人：需要指定联系人到哪个组群。联系人信息（姓名，年龄，性别，移动电话，固定电话，生日，邮箱）
2.用户修改联系人：可以修改联系人所有信息，包括组群
3.用户删除联系人：
4.查询联系人：
    a.按姓名模糊查询
    b.按组群查询
    c.按电话号码模糊查询