Spring Boot 简明教程

Spring Boot - Flyway Database

Flyway 是一款版本控制应用程序，可以轻松可靠地在所有实例上改造您的数据库架构。要了解有关 Flyway 的更多信息，您可以使用以下链接： www.flywaydb.org

Flyway is a version control application to evolve your Database schema easily and reliably across all your instances. To learn more about Flyway, you can use the link − www.flywaydb.org

许多软件项目使用关系数据库。这需要对数据库迁移（也称为架构迁移）进行处理。

Many software projects use relational databases. This requires the handling of database migrations, also often called schema migrations.

在本章中，您将详细了解如何在 Spring Boot 应用程序中配置 Flyway 数据库。

In this chapter, you are going to learn in detail about how to configure Flyway database in your Spring Boot application.

Configuring Flyway Database

首先，从 Spring Initializer 页面 www.start.spring.io 下载 Spring Boot 项目并选择以下依赖项：

First, download the Spring Boot project from Spring Initializer page www.start.spring.io and choose the following dependencies −

Spring Boot Starter Web
Flyway
MySQL
JDBC

Maven 用户可以在 pom.xml 文件中添加以下依赖项。

Maven users can add the following dependencies in pom.xml file.

<dependency>
   <groupId>org.flywaydb</groupId>
   <artifactId>flyway-core</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>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
</dependency>

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-test</artifactId>
   <scope>test</scope>
</dependency>

Gradle 用户可以在 build.gradle 文件中添加以下依赖项。

Gradle users can add the following dependencies in build.gradle file.

compile('org.flywaydb:flyway-core')
compile('org.springframework.boot:spring-boot-starter-jdbc')
compile('org.springframework.boot:spring-boot-starter-web')
compile('mysql:mysql-connector-java')

在应用程序属性中，我们需要配置数据库属性以创建 DataSource，还需要配置我们在应用程序属性中要配置的 flyway 属性。

In application properties, we need to configure the database properties for creating a DataSource and also flyway properties we need to configure in application properties.

对于属性文件用户，请在 application.properties 文件中添加以下属性。

For properties file users, add the below properties in the application.properties file.

spring.application.name = flywayapp

spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.url = jdbc:mysql://localhost:3306/USERSERVICE?autoreconnect=true
spring.datasource.username = root
spring.datasource.password = root
spring.datasource.testOnBorrow = true
spring.datasource.testWhileIdle = true
spring.datasource.timeBetweenEvictionRunsMillis = 60000
spring.datasource.minEvictableIdleTimeMillis = 30000
spring.datasource.validationQuery = SELECT 1
spring.datasource.max-active = 15
spring.datasource.max-idle = 10
spring.datasource.max-wait = 8000

flyway.url = jdbc:mysql://localhost:3306/mysql
flyway.schemas = USERSERVICE
flyway.user = root
flyway.password = root

YAML 用户可以在 application.yml 文件中添加以下属性。

YAML users can add the following properties in application.yml file.

spring:
   application:
      name: flywayapp
   datasource:
      driverClassName: com.mysql.jdbc.Driver
      url: "jdbc:mysql://localhost:3306/USERSERVICE?autoreconnect=true"
      password: "root"
      username: "root"
      testOnBorrow: true
      testWhileIdle: true
      timeBetweenEvictionRunsMillis: 60000
      minEvictableIdleTimeMillis: 30000
      validationQuery: SELECT 1
      max-active: 15
      max-idle: 10
      max-wait: 8000
flyway:
   url: jdbc:mysql://localhost:3306/mysql
   schemas: USERSERVICE
   user: "root"
   password: "root"

现在，在 src/main/resources/db/migration 目录下创建一个 SQL 文件。将 SQL 文件命名为 “V1__Initial.sql”

Now, create a SQL file under the src/main/resources/db/migration directory. Name the SQL file as “V1__Initial.sql”

CREATE TABLE USERS (ID INT AUTO_INCREMENT PRIMARY KEY, USERID VARCHAR(45));
INSERT INTO USERS (ID, USERID) VALUES (1, 'tutorialspoint.com');

主要 Spring Boot 应用程序类文件代码如下所示：

The main Spring Boot application class file code is given below −

package com.tutorialspoint.flywayapp;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class FlywayappApplication {
   public static void main(String[] args) {
      SpringApplication.run(FlywayappApplication.class, args);
   }
}

完整的构建配置文件如下所示。

The complete build configuration file is given below.

Maven – pom.xml

<?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
   http://maven.apache.org/xsd/maven-4.0.0.xsd">

   <modelVersion>4.0.0</modelVersion>
   <groupId>com.tutorialspoint</groupId>
   <artifactId>flywayapp</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>jar</packaging>
   <name>flywayapp</name>
   <description>Demo project for Spring Boot</description>

   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>1.5.9.RELEASE</version>
      <relativePath/> <!-- lookup parent from repository -->
   </parent>

   <properties>
      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
      <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
      <java.version>1.8</java.version>
   </properties>

   <dependencies>
      <dependency>
         <groupId>org.flywaydb</groupId>
         <artifactId>flyway-core</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>mysql</groupId>
         <artifactId>mysql-connector-java</artifactId>
      </dependency>
   </dependencies>

   <build>
      <plugins>
         <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
         </plugin>
      </plugins>
   </build>

</project>

Gradle – build.gradle

buildscript {
   ext {
      springBootVersion = '1.5.9.RELEASE'
   }
   repositories {
      mavenCentral()
   }
   dependencies {
      classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
   }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'

group = 'com.tutorialspoint'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8

repositories {
   mavenCentral()
}
dependencies {
   compile('org.flywaydb:flyway-core')
   compile('org.springframework.boot:spring-boot-starter-jdbc')
   compile('org.springframework.boot:spring-boot-starter-web')
   compile('mysql:mysql-connector-java')
   testCompile('org.springframework.boot:spring-boot-starter-test')
}

你可以创建一个可执行 JAR 文件，并使用下面给出的 Maven 或 Gradle 命令运行 Spring Boot 应用程序：

You can create an executable JAR file, and run the Spring Boot application by using the Maven or Gradle commands given below −

对于 Maven，您可以使用此处所示的命令：

For Maven, you can use the command shown here −

mvn clean install

“BUILD SUCCESS”之后，您可以在目标目录中找到 JAR 文件。

After “BUILD SUCCESS”, you can find the JAR file under the target directory.

对于 Gradle，可以使用此处显示的命令：

For Gradle, you can use the command shown here −

gradle clean build

“BUILD SUCCESSFUL”之后，您可以在 build/libs 目录中找到 JAR 文件。

After “BUILD SUCCESSFUL”, you can find the JAR file under the build/libs directory.

现在，通过使用以下命令运行 JAR 文件 −

Now, run the JAR file by using the following command −

 java –jar <JARFILE>

现在，Tomcat 在端口 8080 上启动，并且可以在控制台窗口中看到 flyway 数据库日志，如下所示。

Now, Tomcat started on the port 8080 and in the console window you can see the flyway database logs as shown here.

你现在可以转到数据库并执行选择查询。

You can now go to the database and do the select queries.