环境
- jdk 6
- tomcat 6.0.53
- sts 4.4.2
- maven 3.2.5
- mysql 5.7
准备
接下来的数据库操作基于 mysql，所以需要一套可用的 mysql 环境。
引入 jdbc 依赖
spring boot 有配置的 jdbc starter，可以直接使用。
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>删除 tomcat-juli
因为默认的数据库连接池依赖的是 tomcat-jdbc，已经依赖进来了 tomcat-juli，所以这个依赖可用直接删除。
删除如下依赖：
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-juli</artifactId>
<version>${tomcat.version}</version>
<scope>provided</scope>
</dependency引入 mysql 连接驱动
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>增加数据库连接信息
在 application.properties 中，增加如下信息：
spring.datasource.url=jdbc:mysql://localhost/spring-boot-demo?useUnicode=true&characterEncoding=UTF-8&useSSL=false
spring.datasource.username=root
spring.datasource.password=123456数据库对象
省略了 get/set 方法。
public class User {
private Integer id;
private String username;
private String userpwd;
private String fullname;
private Integer age;
}api 访问层
增加 UserApi 控制层，并增加获得旅客列表的方法。增加构造函数注入访问数据库的 userDao。
修改完成后，如下：
package jiangbo.demo.user.api;
@RestController
@RequestMapping("/users")
public class UserApi {
private final UserService userService;
public UserApi(UserService userService) {
this.userService = userService;
}
@GetMapping
public List<User> allUsers() {
return userService.findAll();
}
}
service 层
暂时还没有任何的业务，可以直接调用 dao 层，可以增加一个接口来隔离实现。
package jiangbo.demo.user.service;
public interface UserService {
List<User> allUsers();
}package jiangbo.demo.user.service.impl;
@Service
public class UserServiceImpl implements UserService {
private final UserDao userDao;
public UserServiceImpl(UserDao userDao) {
this.userDao = userDao;
}
@Override
public List<User> allUsers() {
return userDao.findAll();
}
}增加 dao
先定义 dao 访问的接口：
package jiangbo.demo.dao;
public interface UserDao {
List<User> findAll();
}在增加 jdbc 的实现。
package jiangbo.demo.user.dao.jdbc;
@Repository
public class JdbcUserDao implements UserDao {
private static final RowMapper<User> USER_ROW_MAPPER = BeanPropertyRowMapper.newInstance(User.class);
private final JdbcTemplate jdbcTemplate;
public JdbcUserDao(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
@Override
public List<User> findAll() {
return jdbcTemplate.query("SELECT * FROM user", USER_ROW_MAPPER);
}
}运行并访问
访问 localhost:8080/demo/users，可以看到页面显示了数据库中存在的数据。
[
{
"id": 1,
"username": "zhangdaming",
"userpwd": "123456",
"fullname": "张大明",
"age": 66
},
{
"id": 2,
"username": "jiangbo",
"userpwd": "123456",
"fullname": "jiangbo",
"age": 44
},
{
"id": 3,
"username": "zhangsan",
"userpwd": "123456",
"fullname": "张三",
"age": 55
}
]附录
完整 pom.xml
<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.22.RELEASE</version>
</parent>
<groupId>jiangbo.demo</groupId>
<artifactId>demo</artifactId>
<version>1.0.0</version>
<packaging>war</packaging>
<properties>
<tomcat.version>7.0.59</tomcat.version>
<jackson.version>2.6.7.3</jackson.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-legacy</artifactId>
<version>1.1.0.RELEASE</version>
</dependency>
<!-- provided -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
</dependencies>
</project>