Spring Boot 入门之持久层篇(三)
一、前言
上一篇《Spring Boot 入门之 Web 篇(二)》介绍了 Spring Boot 的 Web 开发相关的内容,项目的开发离不开数据,因此本篇开始介绍持久层相关的知识。
二、整合 JdbcTemplate
2.1 添加依赖
<!-- jdbc --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <!-- mysql 驱动包 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency>
2.2 配置数据库连接
在 application.properties 中添加:
spring.datasource.driver-class-name=com.mysql.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC spring.datasource.username=root spring.datasource.password=tiger
其中,可以不指定 driver-class-name,因为 spring boot 会自动识别 url。
2.3 测试
2.3.1 建表
在 MySQL 中创建名为 springboot 的数据库,在该库中创建 user 表:
CREATE TABLE `user` ( `id` INT(11) NOT NULL AUTO_INCREMENT, `username` VARCHAR(50) NOT NULL, `password` VARCHAR(64) NOT NULL, `birthday` DATE NOT NULL, PRIMARY KEY (`id`) ) COLLATE='utf8_general_ci' ENGINE=InnoDB AUTO_INCREMENT=3 ;
2.3.2 建实体类
public class User implements Serializable{ private static final long serialVersionUID = -6249397911566315813L; private Integer id; private String username; private String password; private Date birthday; }
setter 和 getter 方法此处省略。
2.3.3 dao 接口
接口和实现类如下:
public interface UserDao { public int insert(User user); public int deleteById(Integer id); public int update(User user); public User getById(Integer id); } @Repository public class UserDaoImpl implements UserDao { @Autowired private JdbcTemplate jdbcTemplate; @Override public int insert(User user) { String sql = "insert into user(id,username,password,birthday) values(?,?,?,?)"; return this.jdbcTemplate.update( sql, user.getId(), user.getUsername(), user.getPassword(), user.getBirthday() ); } @Override public int deleteById(Integer id) { String sql = "delete from user where id = ?"; return this.jdbcTemplate.update(sql,id); } @Override public int update(User user) { String sql = "update user set password = ? where id = ?"; return this.jdbcTemplate.update( sql, user.getPassword(), user.getId() ); } @Override public User getById(Integer id) { String sql = "select * from user where id = ?"; return this.jdbcTemplate.queryForObject(sql, new RowMapper<User>() { @Override public User mapRow(ResultSet rs, int rowNum) throws SQLException { User user = new User(); user.setId(rs.getInt("id")); user.setUsername(rs.getString("username")); user.setPassword(rs.getString("password")); user.setBirthday(rs.getDate("birthday")); return user; } },id); } }
2.3.4 测试类:
@RunWith(SpringRunner.class) @SpringBootTest public class UserDaoTest { @Autowired private UserDao userDao; @Test public void testInsert() { User user = new User(); user.setId(1); user.setUsername("张三"); user.setPassword("zhangsan"); user.setBirthday(new Date()); int result = this.userDao.insert(user); System.out.println(result); } @Test public void testGetById() { User user = this.userDao.getById(1); System.out.println(user.getUsername()); } @Test public void testUpdate() { User user = new User(); user.setId(1); user.setPassword("zhangsan123"); this.userDao.update(user); } @Test public void testDeleteById() { int result = this.userDao.deleteById(1); System.out.println(result); } }
测试结果省略...
如需打印日志,在日志配置文件中添加如下配置:
<logger name="org.springframework.jdbc.core.JdbcTemplate" level="debug"/>
三、整合 Spring-data-jpa
3.1 添加依赖
<!-- jdbc --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <!-- springboot,jpa 整合包--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <!-- mysql 驱动包 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency>
3.2 配置数据库连接
在 application.properties 中添加:
# 数据库连接配置 spring.datasource.driver-class-name=com.mysql.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC spring.datasource.username=root spring.datasource.password=tiger # JPA 配置 spring.jpa.hibernate.ddl-auto=update spring.jpa.show-sql=true
3.3 编码
3.3.1 建表
在 MySQL 中创建名为 springboot 的数据库,在该库中创建 role 表:
CREATE TABLE `role` ( `id` INT(11) NOT NULL AUTO_INCREMENT, `name` VARCHAR(10) NOT NULL, `descr` VARCHAR(100) NULL DEFAULT NULL, PRIMARY KEY (`id`) ) COLLATE='utf8_general_ci' ENGINE=InnoDB ;
注意,主键 ID 为 AUTO_INCREMENT 自增。
3.3.2 建实体类
添加相应的注解
@Entity public class Role implements Serializable{ private static final long serialVersionUID = 3926276668667517847L; @Id @GeneratedValue private Integer id; @Column private String name; @Column private String descr; }
setter 和 getter 方法此处省略。
3.3.3 Repository 接口
public interface RoleRepository extends JpaRepository<Role, Integer>{ }
3.3.4 测试类
@RunWith(SpringRunner.class) @SpringBootTest public class RoleRepositoryTest { @Autowired private RoleRepository roleRepository; @Test public void testInsert() { Role role = new Role(); role.setName("管理员"); role.setDescr("测试"); Role result = this.roleRepository.save(role); System.out.println(result); } @Test public void testFindOne() { Role role = this.roleRepository.findOne(1); System.out.println(role); } @Test public void testUpdate() { Role role = new Role(); role.setId(1); role.setName("管理员"); role.setDescr("控制权限"); Role result = this.roleRepository.save(role); System.out.println(result); } @Test public void testDelete() { this.roleRepository.delete(1); } }
测试结果省略...
四、整合 Mybatis
整合 MyBatis 有两种方式:
1) 使用 mybatis 官方提供的 Spring Boot 整合包实现。
2) 使用 mybatis-spring 整合的方式,也就是传统的方式(推荐,此方式容易控制 MyBatis 的配置)。
4.1 配置依赖
方式一:使用官方整合包
1)添加依赖:
<!-- springboot,mybatis 整合包 --> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.0</version> </dependency> <!-- mysql 驱动包 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency>
2)配置数据库连接:
在 application.properties 中添加:
# 数据源配置 spring.datasource.driver-class-name=com.mysql.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC spring.datasource.username=root spring.datasource.password=tiger # mybatis 配置 mybatis.config-location=classpath:mybatis/mybatis-config.xml mybatis.mapper-locations=classpath:mybatis/mapper/*.xml
方式二:原始 Jar 包 + 手动编程
1)添加依赖:
<!-- jdbc --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <!-- mybatis --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.4.4</version> </dependency> <!-- spring,mybatis整合包 --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.3.1</version> </dependency> <!-- mysql 驱动包 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency>
2)配置数据库连接:
在 application.properties 中添加:
# 数据源配置 spring.datasource.driver-class-name=com.mysql.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC spring.datasource.username=root spring.datasource.password=tiger
3)创建配置类:
@Configuration public class MyBatisConfiguration { @Bean @ConditionalOnMissingBean // 当容器里没有指定的 Bean 的情况下创建该对象 public SqlSessionFactoryBean sqlSessionFactory(DataSource dataSource) { SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean(); // 设置数据源 sqlSessionFactoryBean.setDataSource(dataSource); // 设置mybatis的主配置文件 sqlSessionFactoryBean.setConfigLocation(new ClassPathResource("mybatis/mybatis-config.xml")); // 设置mapper映射文件 PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver(); Resource[] mapperXml; try { mapperXml = resolver.getResources("classpath:mybatis/mapper/*.xml"); sqlSessionFactoryBean.setMapperLocations(mapperXml); } catch (IOException e) { e.printStackTrace(); } // 设置别名包 sqlSessionFactoryBean.setTypeAliasesPackage("com.light.springboot.domain"); return sqlSessionFactoryBean; } @Bean @ConditionalOnBean(SqlSessionFactoryBean.class) // 当 SqlSessionFactoryBean 实例存在时创建对象 public MapperScannerConfigurer mapperScannerConfigurer() { MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer(); mapperScannerConfigurer.setBasePackage("com.light.springboot.mapper"); return mapperScannerConfigurer; } }
以上便是两种方式的配置的不同之处,不同之处就在于如何配置 mybatis 配置文件和 mapper 映射文件的路径。
在 src/main/resources 下创建 mybatis 文件夹,并在 mybatis 文件夹中创建 "mybatis-config.xml" 配置文件,内容如下:
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <settings> <!-- 获取数据库自增主键值 --> <setting name="useGeneratedKeys" value="true"/> <!-- 使用列别名替换列名,默认为 true --> <setting name="useColumnLabel" value="true"/> <!-- 开启驼峰命名转换:Table(create_time) => Entity(createTime) --> <setting name="mapUnderscoreToCamelCase" value="true"/> </settings> </configuration>
mybatis 文件夹下再创建一个 "mapper" 文件夹,里边存放 Mpper 接口对应的 mapper 映射文件。
4.2 测试
4.2.1 建表
在 MySQL 中创建名为 springboot 的数据库,在该库中创建 role 表:
CREATE TABLE `department` ( `id` INT(11) NOT NULL, `name` VARCHAR(10) NOT NULL, `descr` VARCHAR(50) NULL DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB ;
4.2.2 实体类
public class Department implements Serializable{ private static final long serialVersionUID = 6067283535977178571L; private Integer id; private String name; private String descr; }
setet 和 getter 方法省略。
4.2.3 Mapper 接口
@Mapper public interface DepartmentMapper { public void insert(Department department); public Department getById(Integer id); public void update(Department department); public void deleteById(Integer id); }
mybatis/mapper/departmentMapper.xml :
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.light.springboot.dao.DepartmentMapper"> <insert id="insert" parameterType="com.light.springboot.domain.Department"> insert into department(id,name,descr) values(#{id},#{name},#{descr}) </insert> <select id="getById" parameterType="java.lang.Integer" resultType="com.light.springboot.domain.Department"> select id,name,descr from department where id = #{id} </select> <update id="update" parameterType="com.light.springboot.domain.Department"> update department set descr = #{descr} where id = #{id} </update> <delete id="deleteById" parameterType="java.lang.Integer"> delete from department where id = #{id} </delete> </mapper>
4.2.4 测试类
@RunWith(SpringRunner.class) @SpringBootTest public class DepartmentTest { @Autowired private DepartmentMapper departmentMapper; @Test public void testInsert() { Department department = new Department(); department.setId(1); department.setName("研发部"); department.setDescr("开发产品"); this.departmentMapper.insert(department); } @Test public void testGetById() { Department department = this.departmentMapper.getById(1); System.out.println(department); } @Test public void testUpdate() { Department department = new Department(); department.setId(1); department.setDescr("开发高级产品"); this.departmentMapper.update(department); } @Test public void testDeleteById() { this.departmentMapper.deleteById(1); } }
测试结果省略...
五、配置 Druid 数据源
同样地,有两种方式配置:
1)Spring boot,Druid 整合包
2)原始 jar 包 + 手动编程
5.1 Spring boot,Druid 整合包方式
5.1.1 添加依赖
<!-- springboot,druid 整合包 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.8</version> </dependency>
5.1.2 添加配置
在 application.properties 中添加:
spring.datasource.driver-class-name=com.mysql.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC spring.datasource.username=root spring.datasource.password=tiger # 修改数据源 spring.datasource.type=com.alibaba.druid.pool.DruidDataSource spring.datasource.druid.initial-size=5 spring.datasource.druid.min-idle=5 spring.datasource.druid.max-active=20 spring.datasource.druid.max-wait=60000 spring.datasource.druid.time-between-eviction-runs-millis=60000 spring.datasource.druid.min-evictable-idle-time-millis=300000 spring.datasource.druid.validation-query=SELECT 1 FROM DUAL spring.datasource.druid.test-while-idle=true spring.datasource.druid.test-on-borrow=false spring.datasource.druid.test-on-return=false spring.datasource.druid.pool-prepared-statements=true spring.datasource.druid.max-pool-prepared-statement-per-connection-size=20 spring.datasource.druid.filters=stat,wall,log4j
5.2 原始 jar 包 + 手动编程方式
5.2.1 添加依赖
<dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.1.8</version> </dependency>
5.2.2 添加配置
spring.datasource.druid.driverClassName=com.mysql.jdbc.Driver spring.datasource.druid.url=jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC spring.datasource.druid.username=root spring.datasource.druid.password=tiger spring.datasource.druid.initialSize=5 spring.datasource.druid.minIdle=5 spring.datasource.druid.maxActive=20 spring.datasource.druid.maxWait=60000 spring.datasource.druid.timeBetweenEvictionRunsMillis=60000 spring.datasource.druid.min-evictableIdleTimeMillis=300000 spring.datasource.druid.validationQuery=SELECT 1 FROM DUAL spring.datasource.druid.testWhileIdle=true spring.datasource.druid.testOnBorrow=false spring.datasource.druid.testOnReturn=false spring.datasource.druid.poolPreparedStatements=true spring.datasource.druid.maxPoolPreparedStatementPerConnectionSize=20 spring.datasource.druid.filters=stat,wall
注意:配置中都是以 spring.datasource.druid 开头,使用驼峰命名
5.2.3 手动编程
@Configuration public class DruidConfiguration { @ConfigurationProperties(prefix = "spring.datasource.druid") @Bean(initMethod = "init",destroyMethod = "close") public DruidDataSource dataSource() { DruidDataSource ds = new DruidDataSource(); ds.setProxyFilters(Arrays.asList(statFilter())); return ds; } @Bean public Filter statFilter() { StatFilter filter = new StatFilter(); filter.setSlowSqlMillis(5000); filter.setLogSlowSql(true); filter.setMergeSql(true); return filter; } }
通过上文 MyBatis 的测试代码,运行结果如下:
项目已经使用了 Druid 数据源了。
六、配置 Druid 监控
默认情况下,Druid 的监控统计功能和页面是开启的。
我们启动项目,访问 http://localhost:8080/druid/index.html,如下图:
为了保证访问的安全性,我们可以如下配置:
在 application.properties 中添加:
## druid 监控 spring.datasource.druid.web-stat-filter.enabled=true spring.datasource.druid.web-stat-filter.url-pattern=/* spring.datasource.druid.web-stat-filter.exclusions=*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/* ## druid 监控页面 spring.datasource.druid.stat-view-servlet.enabled=true spring.datasource.druid.stat-view-servlet.url-pattern=/druid/* spring.datasource.druid.stat-view-servlet.login-username=druid spring.datasource.druid.stat-view-servlet.login-password=druid123
重启项目,再次访问 http://localhost:8080/druid/index.html 地址时需要身份验证:
七、源码下载
八、参考资料
- Spring Boot 入门之持久层篇(三)
- Spring Boot 入门之持久层篇(三)
- spring Boot学习入门篇-idea开发简单的hello world实例
- Spring Boot 入门
- Spring Boot 入门之消息中间件篇(五)
- Spring Boot 入门demo
- 【转】为什么选择Spring Boot作为微服务的入门级微框架
- Spring Boot入门
- 为什么选择Spring Boot作为微服务的入门级微框架
- Spring Boot 快速入门
- Spring Boot 入门-HolloWorld
- Spring Boot入门初体验(3)--配置logback日志
- Spring Boot入门开发之明月千城(一)
- Sping Boot入门到实战之入门篇(四):Spring Boot自动化配置
- Spring Boot干货系列:(一)优雅的入门篇
- Spring Boot 快速入门
- Spring Boot 入门
- IDEA 快速创建spring boot入门小Demo
- spring boot 入门
- 为什么选择Spring Boot作为微服务的入门级微框架