Spring Boot2 学习笔记之配置 JdbcTemplate （四）

使用 spring boot 访问数据库测试记录

修改 pom.xml 文件

需要在 pom.xml 文件中的dependencys中加入关于 mysql 和 jdbc 的相关包
具体配置如下：

<?xml version="1.0" encoding="UTF-8"?>
<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 https://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>2.4.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.jdbc</groupId>
    <artifactId>demo</artifactId>
    <version>1.0.0</version>
    <name>jdbc</name>
    <description>Jdbc Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

配置数据库连接参数

application.yml

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/db_first
    username: ......
    password: ......
  jdbc:
    template:
      query-timeout: 3

控制器中使用JdbcTemplate

接下来创建一个UserController做测试吧

@Slf4j
@RestController
@RequestMapping("/api")
public class UserController {

    @Autowired
    JdbcTemplate JdbcTemplate;

    @GetMapping("/users")
    public String users(){
        Long res = JdbcTemplate.queryForObject("select count(*) from users",Long.class);

        List<Map<String,Object>> list = JdbcTemplate.queryForList("select * from users");

        log.info("users:{}",list);
        return "hello users num:"+res.toString();
    }
}

了解到开发项目时基本不用 JdbcTemplate,所以作为学习使用就先告一段落