Springboot框架——4.整合jdbc

news/2024/5/22 11:22:50

1.pom.xml中导入依赖：

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId>
</dependency>
<dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.46</version>
</dependency>

2.在Application.properties中指定连接池参数：

spring.datasource.url=jdbc:mysql:///springboot
spring.datasource.username=root
spring.datasource.password=123456#以下参数可不设置
#spring.datasource.driverClassName=com.mysql.jdbc.Driver
#spring.datasource.hikari.idle-timeout=60000
#spring.datasource.hikari.maximum-pool-size=30
#spring.datasource.hikari.minimum-idle=10

3.编写实体类（属性和表字段对应，这里jdbc支持表字段带下划线时自动专为驼峰命名法的属性字段）：

package com.lxj.domain;import java.util.Date;public class User {private Integer id;private String userName;private String passWord;private String name;private Integer age;private Integer sex;private Date birthday;private Date created;private Date updated;private  String note;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getUserName() {return userName;}public void setUserName(String userName) {this.userName = userName;}public String getPassWord() {return passWord;}public void setPassWord(String passWord) {this.passWord = passWord;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public Integer getSex() {return sex;}public void setSex(Integer sex) {this.sex = sex;}public Date getBirthday() {return birthday;}public void setBirthday(Date birthday) {this.birthday = birthday;}public Date getCreated() {return created;}public void setCreated(Date created) {this.created = created;}public Date getUpdated() {return updated;}public void setUpdated(Date updated) {this.updated = updated;}public String getNote() {return note;}public void setNote(String note) {this.note = note;}@Overridepublic String toString() {return "User{" +"id=" + id +", userName='" + userName + '\'' +", name='" + name + '\'' +", age=" + age +", birthday=" + birthday +", note='" + note + '\'' +'}';}
}

4.编写dao:

package com.lxj.dao;import com.lxj.domain.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;import java.util.List;@Repository
public class JdbcDao {@Autowiredprivate JdbcTemplate jdbcTemplate;public List<User> findAll(){//BeanPropertyRowMapper : 可以把同名字段赋值给属性return jdbcTemplate.query("select * from tb_user",new BeanPropertyRowMapper<>(User.class));}
}

@Repository注解便用于将数据访问层 (DAO 层 ) 的类标识为 Spring Bean。具体只需将该注解标注在 DAO类上即可。

5.写一个test类进行测试：

@RunWith(SpringRunner.class)
@SpringBootTest
public class JdbcDaoTest extends TestCase {@Autowiredprivate JdbcDao jdbcDao;@Testpublic void findAll() {jdbcDao.findAll().forEach(user -> {System.out.println(user);});}
}

@RunWith(SpringRunner.class)的作用表明Test测试类要使用注入的类，比如@Autowired注入的类，有了@RunWith(SpringRunner.class)这些类才能实例化到spring容器中，自动注入才能生效。

@SpringBootTest替代了spring-test中的@ContextConfiguration注解，目的是加载ApplicationContext，启动spring容器。使用@SpringBootTest时并没有像@ContextConfiguration一样显示指定locations或classes属性，原因在于@SpringBootTest注解会自动检索程序的配置文件，检索顺序是从当前包开始，逐级向上查找被@SpringBootApplication或@SpringBootConfiguration注解的类。

在方法前加上 @Test ，则该方法即为测试方法，可以执行。

6.打印结果：