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springJDBC01 利用springJDBC操作数据库

程序员文章站 2022-06-11 12:01:52
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1 什么是springJDBC

  spring通过抽象JDBC访问并一致的API来简化JDBC编程的工作量。我们只需要声明SQL、调用合适的SpringJDBC框架API、处理结果集即可。事务由Spring管理,并将JDBC受查异常转换为Spring一致的非受查异常,从而简化开发。

  利用传统的jdbc操作数据库的步骤:获取连接→创建Statement→执行数据操作→获取结果→关闭Statement→关闭结果集→关闭连接;而Spring JDBC通过一个模板类org.springframework. jdbc.core.JdbcTemplate封装了样板式的代码,用户通过模板类就可以轻松地完成大部分数据访问的操作。

 

2 前期准备

  2.1 jar包

    spring-jdbc : springjdbc的包
    mysql : MySQL的驱动包
    dbcp :数据库连接池
    spring-webmvc : springmvc框架包
    annotation :@resource需要用到的包,该包在Tomcat中有,如果是web项目而且运行环境是Tomcat的话就不需要导入这个包了
    junit : 单元测试包

  2.2 数据库(使用mysql数据库5.4)

springJDBC01 利用springJDBC操作数据库
 1 # 创建用户表
 2 CREATE TABLE t_user (
 3     user_id INT AUTO_INCREMENT PRIMARY KEY,
 4     user_name VARCHAR (30),
 5     credits INT,
 6     password VARCHAR (32),
 7     last_visit DATETIME,
 8     last_ip VARCHAR(23)
 9 ) ENGINE = InnoDB;
10 
11 # 查询t_user表的结构
12 DESC t_user;
13 
14 # 创建用户登录日志表
15 CREATE TABLE t_login_log (
16     login_log_id INT AUTO_INCREMENT PRIMARY KEY,
17     user_id INT,
18     ip VARCHAR (23),
19     login_datetime DATETIME
20 ) ENGINE = InnoDB;
21 
22 #查询 t_login_log 表的结构
23 DESC t_login_log;
24 
25 INSERT INTO t_user
26 (user_name, password) 
27 VALUES
28 ("wys", "182838" ); 
29 
30 SELECT * FROM t_user;
相关表

 

3 环境搭建(使用的是eclipse)

  3.1 利用maven导入相关jar包

springJDBC01 利用springJDBC操作数据库
 1 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 ">
 2   <modelVersion>4.0.0</modelVersion>
 3   <groupId>cn.xiangxu</groupId>
 4   <artifactId>baobaotao</artifactId>
 5   <version>0.0.1-SNAPSHOT</version>
 6   <packaging>war</packaging>
 7   <dependencies>
 8       <dependency>
 9           <groupId>org.springframework</groupId>
10           <artifactId>spring-webmvc</artifactId>
11           <version>3.2.8.RELEASE</version>
12       </dependency>
13       <dependency>
14           <groupId>mysql</groupId>
15           <artifactId>mysql-connector-java</artifactId>
16           <version>5.1.37</version>
17       </dependency>
18       <dependency>
19           <groupId>org.springframework</groupId>
20           <artifactId>spring-jdbc</artifactId>
21           <version>3.2.8.RELEASE</version>
22       </dependency>
23       <dependency>
24           <groupId>commons-dbcp</groupId>
25           <artifactId>commons-dbcp</artifactId>
26           <version>1.4</version>
27       </dependency>
28       <dependency>
29           <groupId>javax.annotation</groupId>
30           <artifactId>javax.annotation-api</artifactId>
31           <version>1.2</version>
32       </dependency>
33       <dependency>
34           <groupId>junit</groupId>
35           <artifactId>junit</artifactId>
36           <version>4.12</version>
37       </dependency>
38   </dependencies>
39 </project>
pom.xml

  3.2 创建properties文件,用于存放数据库相关信息

springJDBC01 利用springJDBC操作数据库
1 driverClassName=com.mysql.jdbc.Driver
2 url=jdbc:mysql://127.0.0.1:3306/sampledb
3 username=root
4 password=182838
5 maxActive=10
6 maxWait=3000
mysql.properties

  3.3 创建spring配置文件

    3.3.1 配置properties文件的bean

    3.3.2 配置数据库连接池

    3.3.3 配置jdbcTemplate

    3.3.4 配置组件扫描

springJDBC01 利用springJDBC操作数据库
 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
 4     xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee"
 5     xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop"
 6     xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util"
 7     xmlns:jpa="http://www.springframework.org/schema/data/jpa"
 8     xsi:schemaLocation="
 9          http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
10          http://www.springframework.org/schema/context/spring-context-3.2.xsd
11          http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
12          http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
13          http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
14          http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
15          http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
16          http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
17          http://www.springframework.org/schema/util/spring-util-3.2.xsd">
18     
19     <!-- 读取mysql.properties文件 -->
20     <util:properties id="mysql" location="classpath:config/mysql.properties"/>
21     
22     <!-- 配置连接池 -->
23     <bean id="ds" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">       
24       <property name="driverClassName" value="#{mysql.driverClassName}" />      
25       <property name="url" value="#{mysql.url}" />      
26       <property name="username" value="#{mysql.username}" />      
27       <property name="password" value="#{mysql.password}" />      
28     </bean>
29     
30     <!-- 配置jdbcTemplate -->
31     <bean id="jt" class="org.springframework.jdbc.core.JdbcTemplate">
32         <property name="dataSource" ref="ds"></property>
33     </bean>
34     
35     <!-- 组件扫描 -->
36     <context:component-scan base-package="com.baobaotao"></context:component-scan>
37     
38 </beans>
spring_mysql.xml

  注意:我们不用配置spirng的主控制器,因为我们只是操作持久层;虽然我们用到了spring容器,但是我们可以通过编写代码来启动容器

  3.4 项目结构图

    springJDBC01 利用springJDBC操作数据库

 

4 代码实现数据库操作

  4.1 编写实体类

springJDBC01 利用springJDBC操作数据库
 1 package com.baobaotao.entity;
 2 
 3 import java.io.Serializable;
 4 import java.util.Date;
 5 
 6 public class User implements Serializable {
 7 
 8     private static final long serialVersionUID = -3573627859368072117L;
 9     
10     private Integer userId;
11     private String userName;
12     private Integer credits;
13     private String password;
14     private Date lastVisit;
15     private String lastIp;
16     
17     public User() {
18         super();
19         // TODO Auto-generated constructor stub
20     }
21     
22     public User(Integer userId, String userName, Integer credits, String password, Date lastVisit, String lastIp) {
23         super();
24         this.userId = userId;
25         this.userName = userName;
26         this.credits = credits;
27         this.password = password;
28         this.lastVisit = lastVisit;
29         this.lastIp = lastIp;
30     }
31 
32     @Override
33     public int hashCode() {
34         final int prime = 31;
35         int result = 1;
36         result = prime * result + ((lastIp == null) ? 0 : lastIp.hashCode());
37         return result;
38     }
39     @Override
40     public boolean equals(Object obj) {
41         if (this == obj)
42             return true;
43         if (obj == null)
44             return false;
45         if (getClass() != obj.getClass())
46             return false;
47         User other = (User) obj;
48         if (lastIp == null) {
49             if (other.lastIp != null)
50                 return false;
51         } else if (!lastIp.equals(other.lastIp))
52             return false;
53         return true;
54     }
55     public Integer getUserId() {
56         return userId;
57     }
58     public void setUserId(Integer userId) {
59         this.userId = userId;
60     }
61     public String getUserName() {
62         return userName;
63     }
64     public void setUserName(String userName) {
65         this.userName = userName;
66     }
67     public Integer getCredits() {
68         return credits;
69     }
70     public void setCredits(Integer credits) {
71         this.credits = credits;
72     }
73     public String getPassword() {
74         return password;
75     }
76     public void setPassword(String password) {
77         this.password = password;
78     }
79     public Date getLastVisit() {
80         return lastVisit;
81     }
82     public void setLastVisit(Date lastVisit) {
83         this.lastVisit = lastVisit;
84     }
85     public String getLastIp() {
86         return lastIp;
87     }
88     public void setLastIp(String lastIp) {
89         this.lastIp = lastIp;
90     }
91 
92     @Override
93     public String toString() {
94         return "User [userId=" + userId + ", userName=" + userName + ", credits=" + credits + ", password=" + password
95                 + ", lastVisit=" + lastVisit + ", lastIp=" + lastIp + "]";
96     }
97 
98 }
User.java
springJDBC01 利用springJDBC操作数据库
 1 package com.baobaotao.entity;
 2 
 3 import java.io.Serializable;
 4 import java.util.Date;
 5 
 6 public class LoginLog implements Serializable {
 7 
 8     private static final long serialVersionUID = 5176708814959439551L;
 9     
10     private Integer loginLogId;
11     private String userId;
12     private String ip;
13     private Date loginDatetime;
14     @Override
15     public int hashCode() {
16         final int prime = 31;
17         int result = 1;
18         result = prime * result + ((ip == null) ? 0 : ip.hashCode());
19         result = prime * result + ((loginDatetime == null) ? 0 : loginDatetime.hashCode());
20         result = prime * result + ((loginLogId == null) ? 0 : loginLogId.hashCode());
21         result = prime * result + ((userId == null) ? 0 : userId.hashCode());
22         return result;
23     }
24     @Override
25     public boolean equals(Object obj) {
26         if (this == obj)
27             return true;
28         if (obj == null)
29             return false;
30         if (getClass() != obj.getClass())
31             return false;
32         LoginLog other = (LoginLog) obj;
33         if (ip == null) {
34             if (other.ip != null)
35                 return false;
36         } else if (!ip.equals(other.ip))
37             return false;
38         if (loginDatetime == null) {
39             if (other.loginDatetime != null)
40                 return false;
41         } else if (!loginDatetime.equals(other.loginDatetime))
42             return false;
43         if (loginLogId == null) {
44             if (other.loginLogId != null)
45                 return false;
46         } else if (!loginLogId.equals(other.loginLogId))
47             return false;
48         if (userId == null) {
49             if (other.userId != null)
50                 return false;
51         } else if (!userId.equals(other.userId))
52             return false;
53         return true;
54     }
55     public Integer getLoginLogId() {
56         return loginLogId;
57     }
58     public void setLoginLogId(Integer loginLogId) {
59         this.loginLogId = loginLogId;
60     }
61     public String getUserId() {
62         return userId;
63     }
64     public void setUserId(String userId) {
65         this.userId = userId;
66     }
67     public String getIp() {
68         return ip;
69     }
70     public void setIp(String ip) {
71         this.ip = ip;
72     }
73     public Date getLoginDatetime() {
74         return loginDatetime;
75     }
76     public void setLoginDatetime(Date loginDatetime) {
77         this.loginDatetime = loginDatetime;
78     }
79     public LoginLog() {
80         super();
81         // TODO Auto-generated constructor stub
82     }
83     public LoginLog(Integer loginLogId, String userId, String ip, Date loginDatetime) {
84         super();
85         this.loginLogId = loginLogId;
86         this.userId = userId;
87         this.ip = ip;
88         this.loginDatetime = loginDatetime;
89     }
90     @Override
91     public String toString() {
92         return "LoginLog [loginLogId=" + loginLogId + ", userId=" + userId + ", ip=" + ip + ", loginDatetime="
93                 + loginDatetime + "]";
94     }    
95     
96 }
LoginLog.java

  4.2 编写UserDao接口

springJDBC01 利用springJDBC操作数据库
 1 package com.baobaotao.dao;
 2 
 3 import java.util.List;
 4 
 5 import com.baobaotao.entity.User;
 6 
 7 public interface UserDao {
 8     /**
 9      * 向用户表中添加记录
10      * @param user 用户表实体对象
11      */
12     public void insert(User user);
13     
14     /**
15      * 查询所有用户数据
16      * @return 由查询到记录组成的集合
17      */
18     public List<User> findAll();
19 
20 }
UserDao.java

  4.3 编写UserDao接口的实现类UserDaoImpl  

springJDBC01 利用springJDBC操作数据库
 1 package com.baobaotao.dao;
 2 
 3 import java.sql.ResultSet;
 4 import java.sql.SQLException;
 5 import java.util.List;
 6 
 7 import javax.annotation.Resource;
 8 
 9 import org.springframework.jdbc.core.JdbcTemplate;
10 import org.springframework.jdbc.core.RowMapper;
11 import org.springframework.stereotype.Repository;
12 
13 import com.baobaotao.entity.User;
14 
15 @Repository("userDao")
16 public class UserDaoImpl implements UserDao {
17     
18     @Resource(name="jt")
19     private JdbcTemplate jt;
20 
21     public void insert(User user) {
22         
23         String sql = "INSERT INTO t_user " + 
24                 "(user_name, password) " + 
25                 "VALUES " + 
26                 "(?, ?) ";
27         Object [] args = {user.getUserName(), user.getPassword()};
28         Integer num = jt.update(sql, args);
29         if(num > 0) {
30             System.out.println("插入数据成功");
31         } else {
32             System.out.println("插入数据失败");
33         }
34         
35     }
36     
37     public List<User> findAll() {
38         String sql = "SELECT * FROM t_user ";
39         List<User> users = jt.query(sql, new UserRowMapper());
40         return users;
41     }
42     
43     /**
44      * 结果集处理:经每一条查询记录转变成一个实体对象
45      * @author 三少
46      *
47      */
48     class UserRowMapper implements RowMapper<User> {
49 
50         public User mapRow(ResultSet rs, int rowNum) throws SQLException {
51             User user = new User();
52             user.setUserId(rs.getInt("user_id"));
53             user.setUserName(rs.getString("user_name"));
54             user.setCredits(rs.getInt("credits"));
55             user.setPassword(rs.getString("password"));
56             user.setLastVisit(rs.getDate("last_visit"));
57             user.setLastIp(rs.getString("last_ip"));
58             return user;
59         }
60     }
61     
62 }
UserDaoImpl

    使用springJDBC操作数据库时,程序员只需要编写相关的sql语句,待定参数可以用?代替,然后调用JdbcTemplate类的相关方法来执行sql语句就行啦。

    JdbcTemplate类中的主要方法

      execute方法:可以用于执行任何SQL语句,一般用于执行DDL语句; 
      update方法及batchUpdate方法:update方法用于执行新增、修改、删除等语句; 
      batchUpdate方法用于执行批处理相关语句; 
      query方法及queryForXXX方法:用于执行查询相关语句 
      call方法:用于执行存储过程、函数相关语句。

      注意:

        使用query方法时有三个参数

          参数1  sql语句字符串

          参数2  未知参数组

          参数3  查询结果处理(就是讲每一条查询记录变成一个实体对象,三少的一般做法是编写一个实现了RowMapper接口的内部类,然后创建一个该内部类对象来作为参数3

  4.4 项目结构图

    springJDBC01 利用springJDBC操作数据库

 

5 测试类

  5.1 测试前需要启动spring容器,因为我们的代码中使用到了spring容器的功能

    springJDBC01 利用springJDBC操作数据库

  5.2 编写测试方法

springJDBC01 利用springJDBC操作数据库
 1 package testDao;
 2 
 3 import java.util.List;
 4 
 5 import org.junit.Before;
 6 import org.junit.Test;
 7 import org.springframework.context.ApplicationContext;
 8 import org.springframework.context.support.ClassPathXmlApplicationContext;
 9 
10 import com.baobaotao.dao.UserDao;
11 import com.baobaotao.entity.User;
12 
13 public class TestDao {
14     
15     private ApplicationContext ac;
16     private UserDao userDao;
17     
18     @Before
19     public void init() {
20         ac = new ClassPathXmlApplicationContext("config/spring_mysql.xml"); // 启动容器
21         System.out.println(ac);
22         
23         userDao = ac.getBean("userDao", UserDao.class); // 利用容器创建对象
24         System.out.println(userDao);
25     }
26     
27     /**
28      * 测试插入数据
29      */
30     @Test
31     public void test01() {
32         User user = new User();
33         user.setUserName("wym");
34         user.setPassword("111");
35         
36         userDao.insert(user);
37     }
38     
39     /**
40      * 测试查询所有数据
41      */
42     @Test
43     public void test02() {
44         List<User> users = userDao.findAll();
45         for(User user : users) {
46             System.out.println(user);
47         }
48     }
49     
50     
51 }
测试类

 

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