Ruoyi's solution to error reporting after integrating flyway

ruoyi Series framework is a very good source platform in open source , Use loose open source protocols to open source code . Whether it's a single version 、 Front end and back-end separation and even micro service architecture , Corresponding codes are provided . be based on ruoyi You can make your own background system , You can also learn the integration of many technologies .

and flyway yes java The automatic database script management tool , Use flyway It can be automatically managed when the application is upgraded sql Script , So as to avoid the problems caused by users' forgetting and not executing scripts . It is very easy to use in multi version development sql Version management component .

Official ruoyi The framework is not integrated flyway, In the open source ecosystem, there are some fans based on ruoyi To integrate . This article will briefly share based on ruoyi Single version （ Other versions are similar ） How to integrate flyway, What problems will you encounter in the process of integration , Share three solutions at the same time .

One 、flyway stay ruoyi Integration in the framework

1、 stay ruoyi Of pom.xml In the definition of flyway rely on , The specific code is as follows ：

<!--  Database version control core depends on  -->
<dependency>
	<groupId>org.flywaydb</groupId>
	<artifactId>flyway-core</artifactId>
</dependency>

​​

<!--  Database version control plug-in  -->
<plugin>
	<groupId>org.flywaydb</groupId>
	<artifactId>flyway-maven-plugin</artifactId>
</plugin>

2、 System profile application.yml Definition flyway Related configuration

flyway:
    #  Character encoding 
    encoding: utf-8
    #  A description of the baseline version when performing the migration 
    baseline-description: BaseLineInitialize
    #  If the connected database is not empty , Whether to initialize 
    #  Find the target when migrating schema Non empty , And with tables without metadata , Whether to perform benchmark migration automatically , Default false.
    baseline-on-migrate: true
    #  Appoint  baseline  Version number of , The default value is  1,  Below this version number  SQL  file , migrate  When it's ignored 
    #  Start the benchmark migration against the existing schema The version of is labeled , The default value is 1.
    baseline-version: 1.0.0
    #  Whether to turn on verification 
    #  Check when migrating , The default is  true
    validate-on-migrate: true
    #  It's better to open the development environment  outOfOrder,  Production environment shut down  outOfOrder
    #  Whether to allow unordered migration , Default  false
    out-of-order: true
    #  Whether to ignore error migration when reading metadata table , Default false
    ignore-future-migrations: false
    #  When the connection is initialized SQL
    init-sql: SELECT * FROM pg_tables WHERE tablename NOT LIKE'pg%' AND tablename NOT LIKE'sql_%' ORDER BY tablename;

3、 Definition flyway To configure bean

package com.hngtghy.framework.config;

import javax.annotation.PostConstruct;
import javax.sql.DataSource;

import org.flywaydb.core.Flyway;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;

@Configuration
public class FlywayConfig {

  @Autowired
  private DataSource dataSource;
  
  //  Character encoding 
  @Value("${flyway.encoding}")
  private String encoding;
  
  //  A description of the baseline version when performing the migration 
  @Value("${flyway.baseline-description}")
  private String baselineDescription;

  //  Whether to perform benchmark migration automatically 
  @Value("${flyway.baseline-on-migrate}")
  private boolean baselineOnMigrate;

  //  Appoint  baseline  Version number of 
  @Value("${flyway.baseline-version}")
  private String baselineVersion;

  //  Check when migrating 
  @Value("${flyway.validate-on-migrate}")
  private boolean validateOnMigrate;
  
  //  Whether to allow unordered migration 
  @Value("${flyway.out-of-order}")
  private boolean outOfOrder;
  
  //  Whether to ignore error migration when reading metadata table 
  @Value("${flyway.ignore-future-migrations}")
  private boolean ignoreFutureMigrations;
  
  //  When the connection is initialized SQL
  @Value("${flyway.init-sql}")
  private String initSql;
  
  @PostConstruct
  public void migrate() {
    Flyway flyway = Flyway.configure()
    		.dataSource(dataSource)
    		.encoding(encoding)
    		.baselineDescription(baselineDescription)
    		.baselineOnMigrate(baselineOnMigrate)
    		.baselineVersion(baselineVersion)
    		.validateOnMigrate(validateOnMigrate)
    		.outOfOrder(outOfOrder)
    		.ignoreFutureMigrations(ignoreFutureMigrations)
    		.initSql(initSql)
    		.load();
    flyway.migrate();
  }

}

4、 The most important thing is never to forget resources Define initial script under directory , Here's the picture ：

5、 Start up main Remember to write the following code in the entry ：

@SpringBootApplication(exclude = { DataSourceAutoConfiguration.class,FlywayAutoConfiguration.class })

Basically complete the above steps flyway The introduction of framework . The road to success is always full of obstacles , This is no exception , start-up main Method , You'll find that , The system reports an error .

Don't panic in case of abnormality , Because panic can't solve the problem . Check the log carefully , The main cause of the error is the system loading sys_config The table cannot be found when the information of . Why does the system load at startup ？ Look forward to , Found in the ConfigServiceImpl Define a class loading initialization method ：

   /**
     *  When the project starts , Initialize parameters to cache 
     */
    @PostConstruct
    public void init()
    {
        loadingConfigCache();
    }

The reason for this problem is this . Because during initialization , Will query the table from the database . While using flyway after , The database structure has not been initialized , So it must be wrong . The solution is , Give Way flyway Start... First , Initialize the database structure , Then run the corresponding parameters into the cache . Here are three ways to solve this problem .

Two 、 solve flyway Integrated error reporting method

1、 For small-scale applications , You can disable loading data into the cache during initialization . Because the data will be loaded into the cache during actual access , Therefore, the effect of speeding up is not very obvious . This solution is relatively simple . Will involve @PostConstruct Initially loaded bean Are commented out .

2、 What if you want to have an initial cache after the application system starts ？ It's OK, too . See a blogger's article for specific methods , This way can also be a good solution . Blog address ：https://www.easck.com/cos/2021/0626/619426.shtml , This article will not be repeated .

3、 stay springboot Use in @DependsOn Annotation to set flyway Startup sequence . Set the class of this annotation , You must initialize the pre class before starting . This is a good way to avoid exceptions . The specific code example is as follows ：​​​​​​​

@Service
@DependsOn("flywayConfig")
public class ConfigServiceImpl implements IConfigService

Through the above configuration, you can complete flyway Integration of , And successfully start the application .

summary ： This article briefly introduces ruoyi System and flyway Database version control technology . It also explains how to ruiyi In the integration flyway Components . It focuses on integration flyway And three different solutions to this problem .