Use other spring beans in liquibase CustomTaskChange class - java

I need to do some data migration, which is too complex to do it in a liquibase changeset. We use spring
That's why I wrote a class implementing the liquibase.change.custom.CustomTaskChange class. I then reference it from within a changeset.
All is fine to this point.
My question is:
Is it possible to get access to the other spring beans from within such a class?
When I try to use an autowired bean in this class, it's null, which makes me think that the autowiring is simply not done at this point?
I've also read in some other thread, that the Liquibase bean must be initialized before all other beans, is that correct?
Here is a snippet of the class I wrote:
#Component
public class UpdateJob2 implements CustomTaskChange {
private String param1;
#Autowired
private SomeBean someBean;
#Override
public void execute(Database database) throws CustomChangeException {
try {
List<SomeObject> titleTypes = someBean.getSomeObjects(
param1
);
} catch (Exception e) {
throw new CustomChangeException();
}
...
I get an exception and when debugging I can see that someBean is null.
Here is the config for the SpringLiquibase:
#Configuration
#EnableTransactionManagement(proxyTargetClass = true)
#ComponentScan({
"xxx.xxx.."})
public class DatabaseConfiguration {
#Bean
public SpringLiquibase springLiquibase() {
SpringLiquibase liquibase = new SpringLiquibase();
liquibase.setDataSource(dataSource());
liquibase.setChangeLog("classpath:liquibase-changelog.xml");
return liquibase;
}
...
Some more config:
<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.1.xsd">
<includeAll path="dbschema"/>
</databaseChangeLog>
And here the call from the changeset:
<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.1.xsd">
<changeSet id="201509281536" author="sr">
<customChange class="xxx.xxx.xxx.UpdateJob2">
<param name="param1" value="2" />
</customChange>
</changeSet>

I'm currently running through this problem as well...After hours of digging, I found 2 solutions, no AOP is needed.
Liquibase version: 4.1.1
Solution A
In the official example of customChange
https://docs.liquibase.com/change-types/community/custom-change.html
In CustomChange.setFileOpener, ResourceAccessor actually is an inner class SpringLiquibase$SpringResourceOpener, and it has a member 'resourceLoader', which is indeed an ApplicationContext. Unfortunately, it's private and no getter is available.
So here comes an ugly solution: USE REFLECTION TO GET IT AND INVOKE getBean
Solution B (More elegant)
Before we get started, let's see some basic facts about Liquibase. The official way of integrating Liquibase with Spring Boot is by using:
org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration$LiquibaseConfiguration
This is a conditional inner config bean for creating SpringLiquibase ONLY WHEN SpringLiquibase.class IS MISSING
#Configuration
#ConditionalOnMissingBean(SpringLiquibase.class)
#EnableConfigurationProperties({ DataSourceProperties.class,
LiquibaseProperties.class })
#Import(LiquibaseJpaDependencyConfiguration.class)
public static class LiquibaseConfiguration {...}
So we can create our own SpringLiquibase by adding a liquibase config bean
#Getter
#Configuration
#EnableConfigurationProperties(LiquibaseProperties.class)
public class LiquibaseConfig {
private DataSource dataSource;
private LiquibaseProperties properties;
public LiquibaseConfig(DataSource dataSource, LiquibaseProperties properties) {
this.dataSource = dataSource;
this.properties = properties;
}
#Bean
public SpringLiquibase liquibase() {
SpringLiquibase liquibase = new BeanAwareSpringLiquibase();
liquibase.setDataSource(dataSource);
liquibase.setChangeLog(this.properties.getChangeLog());
liquibase.setContexts(this.properties.getContexts());
liquibase.setDefaultSchema(this.properties.getDefaultSchema());
liquibase.setDropFirst(this.properties.isDropFirst());
liquibase.setShouldRun(this.properties.isEnabled());
liquibase.setLabels(this.properties.getLabels());
liquibase.setChangeLogParameters(this.properties.getParameters());
liquibase.setRollbackFile(this.properties.getRollbackFile());
return liquibase;
}
}
inside which we new an extended class of SpringLiquibase: BeanAwareSpringLiquibase
public class BeanAwareSpringLiquibase extends SpringLiquibase {
private static ResourceLoader applicationContext;
public BeanAwareSpringLiquibase() {
}
public static final <T> T getBean(Class<T> beanClass) throws Exception {
if (ApplicationContext.class.isInstance(applicationContext)) {
return ((ApplicationContext)applicationContext).getBean(beanClass);
} else {
throw new Exception("Resource loader is not an instance of ApplicationContext");
}
}
public static final <T> T getBean(String beanName) throws Exception {
if (ApplicationContext.class.isInstance(applicationContext)) {
return ((ApplicationContext)applicationContext).getBean(beanName);
} else {
throw new Exception("Resource loader is not an instance of ApplicationContext");
}
}
#Override
public void setResourceLoader(ResourceLoader resourceLoader) {
super.setResourceLoader(resourceLoader);
applicationContext = resourceLoader;
}}
BeanAwareSpringLiquibase has a static reference to ResourceLoader aforementioned. On Spring Bootstartup, 'setResourceLoader' defined by ResourceLoaderAware interface will be invoked automatically before 'afterPropertiesSet' defined by InitializingBean interface, thus the code execution will be like this:
Spring Boot invokes setResourceLoader, injecting resourceLoader(applicationContext) to BeanAwareSpringLiquibase.
Spring Boot invokes afterPropertiesSet, performing Liquibase update including customChange, by now you already have full access to applicationContext
PS:
Remember adding your Liquibase config bean package path to #ComponentScan or it will still use LiquibaseAutoConfiguration instead of our own LiquibaseConfig.
Prepare all beans you need in 'setUp' before 'execute' would be a better convention.

The classes referenced in your changeset.xml are not managed by Spring, so the cool stuff like DI will not work.
What you can do is to inject Spring beans into Non-Spring objects. See this answer: https://stackoverflow.com/a/1377740/4365460

I accomplished this by overriding the Spring Liquibase configuration and setting a static field on the custom task. Setting the fields in the configuration ensures that it is set before the changeset runs.
This is not possible to do with every bean, because some beans (like JPA repositories) are dependent on the liquibase bean. Liquibase runs changelogs when the SpringLiquibase bean is initialized, but the entire Spring context is not completely loaded at that point. If you try to autowire a bean that depends on liquibase, you'll get an exception on startup.
I also think that this technique is safer than exposing the entire application context statically. Only the fields that are needed are passed to the task, and those are not publicly accessible afterward.
/**
Task that has a static member that will be set in the LiquibaseConfiguration class.
*/
public class MyCustomTask implements CustomTaskChange {
private static MyBean myBean;
public static void setMyBean(MyBean myBean) {
MyCustomTask.myBean = myBean;
}
#Override
public void execute(Database database) throws CustomChangeException {
try {
JdbcConnection jdbcConnection = (JdbcConnection) database.getConnection();
// do stuff using myBean
} catch (DatabaseException | SQLException e) {
throw new CustomChangeException(e);
}
}
}
/**
Extend SpringBoot Liquibase Auto-Configuration
org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration.LiquibaseConfiguration
*/
#Configuration(proxyBeanMethods = false)
#ConditionalOnMissingBean(SpringLiquibase.class)
#EnableConfigurationProperties({DataSourceProperties.class, LiquibaseProperties.class})
public static class MyLiquibaseConfiguration
extends LiquibaseAutoConfiguration.LiquibaseConfiguration {
/**
* Autowire myBean and set it on {#link MyCustomTask}.
*
* #param properties The {#link LiquibaseProperties} to configure Liquibase.
* #param myBean my bean.
*/
public MigrationLiquibaseConfiguration(LiquibaseProperties properties, MyBean myBean) {
super(properties);
MyCustomTask.setMyBean(myBean);
}
}

Related

How to create datasource bean at runtime without crashing app in Spring?

I am connecting to multiple datasources but sometimes some datasources may be offline and at that time I am geting errors on app and application is failing at startup.
I want to skip datasource configuration at startup... I have tried several ways by adding
spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration
to the application.properties and also I have tried adding
#SpringBootApplication(exclude={DataSourceAutoConfiguration.class})
to the main class but still it tries to configure the datasource.
I also tried to use #Lazy annotation on all methods and on constructor as below but still getting error while creating fooEntityManagerFactory
#Lazy
#Configuration
#EnableJpaRepositories(basePackages = "com.heyo.tayo.repository.foo", entityManagerFactoryRef = "fooEntityManagerFactory", transactionManagerRef = "fooTransactionManager")
public class PersistencefooConfiguration {
#Autowired
private DbContextHolder dbContextHolder;
#Lazy
#Bean
#ConfigurationProperties("tay.datasource.foo")
public DataSourceProperties fooDataSourceProperties() {
return new DataSourceProperties();
}
#Lazy
#Bean
#ConfigurationProperties("tay.datasource.foo.configuration")
public DataSource fooDataSource() {
DataSource dataSource = fooDataSourceProperties().initializeDataSourceBuilder()
.type(BasicDataSource.class).build();
dbContextHolder.addNewAvailableDbType(DbTypeEnum.foo);
return dataSource;
}
#Lazy
#Bean(name = "fooEntityManagerFactory")
public LocalContainerEntityManagerFactoryBean fooEntityManagerFactory(
EntityManagerFactoryBuilder builder) {
//THE CODE IS FAILING AT BELOW RETURN CASE
return builder
.dataSource(fooDataSource())
.packages("com.heyo.tayo.model.foo")
.build();
}
#Lazy
#Bean
public PlatformTransactionManager fooTransactionManager(
final #Qualifier("fooEntityManagerFactory") LocalContainerEntityManagerFactoryBean fooEntityManagerFactory) {
return new JpaTransactionManager(fooEntityManagerFactory.getObject());
}
}
I have multiple classes like above for different configs for different datasources and I am adding them to available dbs static list at datasource Bean.
Here is my dbadapter factory class.
Here is my dbAdaptor factory that creates corresponding db adaptor
#Service
public class DbAdapterFactory {
#Autowired
private BeanFactory beanFactory;
#Autowired
private DbContextHolder dbContextHolder;
public DBAdapter dbAdapter(){
DbTypeEnum currentDb = dbContextHolder.getCurrentDb();
DBAdapter dbAdapter = null;
if(currentDb == DbTypeEnum.FOODB) {
dbAdapter = beanFactory.getBean(foodbadaptor.class);
} else {
dbAdapter = beanFactory.getBean(koodbadaptor.class);
}
return dbAdapter;
}
Here is db context holder that makes operation like setting default db or getting current db etc.:
#Component
public class DbContextHolder {
private DbTypeEnum dbType = DbTypeEnum.FOODB;
private Set<DbTypeEnum> availableDbTypes = new HashSet<>();
public void setCurrentDb(DbTypeEnum dbType) {
this.dbType = dbType;
}
public DbTypeEnum getCurrentDb() {
return this.dbType;
}
public List<DbTypeEnum> getAvailableDbTypes() {
return new ArrayList<>(availableDbTypes);
}
public void addNewAvailableDbType(DbTypeEnum dbTypeEnum) {
availableDbTypes.add(dbTypeEnum);
}
}
I made all #Lazy or tried #SpringBootApplication(exclude={DataSourceAutoConfiguration.class}) but still something is calling to create bean and getting error and app is closing. I want to use that config and datasource in a try-catch block and don't stop application at runtime. How can I achieve this or what am I missing on that configs or annotations ?
I believe that you can simply add in your application properties
spring.sql.init.continue-on-error=true
According to the Spring Boot 2.5.5 user guide:
https://docs.spring.io/spring-boot/docs/2.5.5/reference/htmlsingle/#howto-initialize-a-database-using-spring-jdbc
Spring Boot enables the fail-fast feature of its script-based database initializer. If the scripts cause exceptions, the application fails to start. You can tune that behavior by setting spring.sql.init.continue-on-error.
Depending on your spring boot version the property will be named either
spring.sql.init.continue-on-error
or before Spring Boot 2.5
spring.datasource.continue-on-error
It is so dumb but I solved the problem by adding following to application.properties.
spring.jpa.database=sql_server
I have no idea why I need to specify that explicitly in properties file but the problem is solved. I will search for it

Spring Dependency Injection into JPA entity listener

I need to have a Spring dependency injected into a JPA entity listener. I know I can solve this using #Configurable and Spring's AspectJ weaver as javaagent, but this seems like a hacky solution. Is there any other way to accomplish what I'm trying to do?
Since Hibernate 5.3 org.hibernate.resource.beans.container.spi.BeanContainer and Spring 5.1 org.springframework.orm.hibernate5.SpringBeanContainer you do not need to extra autowiring effort any more. See details of this feature in https://github.com/spring-projects/spring-framework/issues/20852
Simply annotate your EntityListener class with #Component, and do any autowiring like so:
#Component
public class MyEntityListener{
private MySpringBean bean;
#Autowired
public MyEntityListener(MySpringBean bean){
this.bean = bean;
}
#PrePersist
public void prePersist(final Object entity) {
...
}
}
In Spring Boot the configuration of LocalContainerEntityManagerFactoryBean is done automatically in org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration.
Outside of Spring Boot, you have to register SpringBeanContainer to Hibernate:
LocalContainerEntityManagerFactoryBean emfb = ...
emfb.getJpaPropertyMap().put(AvailableSettings.BEAN_CONTAINER, new SpringBeanContainer(beanFactory));
Another trick is to implement an utility class with static method that helps you to use Spring beans everywhere, not only in managed classes:
#Component
public final class BeanUtil {
private static ApplicationContext context;
private BeanUtil(ApplicationContext context) {
BeanUtil.context = context;
}
public static <T> T getBean(Class<T> clazz) throws BeansException {
Assert.state(context != null, "Spring context in the BeanUtil is not been initialized yet!");
return context.getBean(clazz);
}
}
Here's a solution in Kotlin (Spring Boot 2.3.9, Hibernate 5.4.29.Final). First part is similar to Matthias' answer. However, the second part was needed even though it's a Spring Boot application.
Bean declaration
#Component
class EntityXyzListener(val mySpringBean: MySpringBean) {
#PostLoad
fun afterLoad(entityXyz: EntityXyz) {
// Injected bean is available here. (In my case the bean is a
// domain service that I make available to the entity.)
entityXyz.mySpringBean= mySpringBean
}
}
Datasource configuration
I already had this datasource #Configuration in my spring boot app. I only had to add the line of code that puts the BEAN_CONTAINER property in the jpaPropertyMap.
#Resource
lateinit var context: AbstractApplicationContext
#Primary
#Bean
#Qualifier("appDatasource")
#ConfigurationProperties(prefix = "spring.datasource")
fun myAppDatasource(): DataSource {
return DataSourceBuilder.create().build()
}
#Primary
#Bean(name = ["myAppEntityManagerFactory"])
fun entityManagerFactoryBean(builder: EntityManagerFactoryBuilder): LocalContainerEntityManagerFactoryBean {
val localContainerEntityManagerFactoryBean =
builder
.dataSource(myAppDatasource())
.packages("com.mydomain.myapp")
.persistenceUnit("myAppPersistenceUnit")
.build()
// the line below was the long-sought solution :^)
localContainerEntityManagerFactoryBean.jpaPropertyMap.put(
AvailableSettings.BEAN_CONTAINER, SpringBeanContainer(context.beanFactory))
return localContainerEntityManagerFactoryBean
}
You can try this solution
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
public final class AutowireHelper implements ApplicationContextAware {
private static final AutowireHelper INSTANCE = new AutowireHelper();
private static ApplicationContext applicationContext;
private AutowireHelper() {
}
/**
* Tries to autowire the specified instance of the class if one of the specified beans which need to be autowired
* are null.
*
* #param classToAutowire the instance of the class which holds #Autowire annotations
* #param beansToAutowireInClass the beans which have the #Autowire annotation in the specified {#classToAutowire}
*/
public static void autowire(Object classToAutowire, Object... beansToAutowireInClass) {
for (Object bean : beansToAutowireInClass) {
if (bean == null) {
applicationContext.getAutowireCapableBeanFactory().autowireBean(classToAutowire);
return;
}
}
}
/**
* #return the singleton instance.
*/
public static AutowireHelper getInstance() {
return INSTANCE;
}
#Override
public void setApplicationContext(final ApplicationContext applicationContext) {
AutowireHelper.applicationContext = applicationContext;
}
}
and then
#Autowired
SomeService thatToAutowire;
AutowireHelper.autowire(this, this.thatToAutowire);//this in the method
Extending a bit the above responses:
Since Hibernate 5.3 org.hibernate.resource.beans.container.spi.BeanContainer and Spring 5.1. You can use this to post process loaded domain entities for instance. Instead of using the aspect.
See:
https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/orm/hibernate5/SpringBeanContainer.html
In your config:
#Bean
LocalContainerEntityManagerFactoryBean customCartEntityManagerFactory(DataSource customCartDataSource, EntityManagerFactoryBuilder builder, ConfigurableListableBeanFactory beanFactory) {
var mf = builder
.dataSource(customCartDataSource)
.packages("com.my.domain")
.build();
mf.getJpaPropertyMap().put(AvailableSettings.BEAN_CONTAINER, new SpringBeanContainer(beanFactory));
return mf;
}
In your entity bean:
#EntityListeners(MyEntityListener.class)
The listener, notice no #Component decoration.
#Slf4j
public class MyEntityListener implements BeanFactoryAware, InitializingBean {
private final BeanConfigurerSupport beanConfigurerSupport = new BeanConfigurerSupport();
public CustomCartEntityListener() {
log.info("MyEntityListener created");
}
#PostLoad
public void postLoad(MyEntity entity) {
beanConfigurerSupport.configureBean(entity);
}
#Override
public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
this.beanConfigurerSupport.setBeanWiringInfoResolver(new AnnotationBeanWiringInfoResolver());
this.beanConfigurerSupport.setBeanFactory(beanFactory);
}
#Override
public void afterPropertiesSet() {
this.beanConfigurerSupport.afterPropertiesSet();
log.info("MyEntityListener initialized");
}
}

Spring with MyBatis: expected single matching bean but found 2

I've been using Spring with MyBatis and it's been working really well for a single database. I ran into difficulties when trying to add another database (see reproducible example on Github).
I'm using Spring Java configuration (i.e. not XML). Most of the examples I've seen show how to achieve this using XML.
I have two data configuration classes (A & B) like this:
#Configuration
#MapperScan("io.woolford.database.mapper")
public class DataConfigDatabaseA {
#Bean(name="dataSourceA")
public DataSource dataSourceA() throws SQLException {
SimpleDriverDataSource dataSource = new SimpleDriverDataSource();
dataSource.setDriver(new com.mysql.jdbc.Driver());
dataSource.setUrl("jdbc:mysql://" + dbHostA + "/" + dbDatabaseA);
dataSource.setUsername(dbUserA);
dataSource.setPassword(dbPasswordA);
return dataSource;
}
#Bean
public SqlSessionFactory sqlSessionFactory() throws Exception {
SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
sessionFactory.setDataSource(dataSourceA());
return sessionFactory.getObject();
}
}
Two mappers, and a service that autowires the mappers:
#Service
public class DbService {
#Autowired
private DbMapperA dbMapperA;
#Autowired
private DbMapperB dbMapperB;
public List<Record> getDabaseARecords(){
return dbMapperA.getDatabaseARecords();
}
public List<Record> getDabaseBRecords(){
return dbMapperB.getDatabaseBRecords();
}
}
The application won't start:
Error creating bean with name 'dataSourceInitializer':
Invocation of init method failed; nested exception is
org.springframework.beans.factory.NoUniqueBeanDefinitionException:
No qualifying bean of type [javax.sql.DataSource] is defined:
expected single matching bean but found 2: dataSourceB,dataSourceA
I've read that it's possible to use the #Qualifier annotation to disambiguate the autowiring, though I wasn't sure where to add it.
Can you see where I'm going wrong?
If you want to use two data sources at same time and they are not primary and secondary, you should disable DataSourceAutoConfiguration by #EnableAutoConfiguration(excludes = {DataSourceAutoConfiguration.class}) on your application annotated by #SpringBootApplication. Afterwards, you can create your own SqlSessionFactory and bundle your own DataSource. If you also want to use DataSourceTransactionManager, you should do that too.
In this case, you haven't disabled DataSourceAutoConfiguration, so spring framework will try to #Autowired only one DataSource but got two, error occurs.
As what I've said before, you should disable DataSourceAutoConfiguration and configure it manually.
You can disable data source auto configuration as following:
#SpringBootApplication
#EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class})
public class YourApplication implements CommandLineRunner {
public static void main (String... args) {
SpringApplication.run(YourApplication.class, args);
}
}
And if you are really want to use multiple databases at same time, I suggest you to registering proper bean manually, such as:
package xyz.cloorc.boot.mybatis;
import org.apache.commons.dbcp.BasicDataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.support.SqlSessionDaoSupport;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Repository;
import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import javax.sql.DataSource;
#Configuration
public class SimpleTest {
private DataSource dsA;
private DataSource dsB;
#Bean(name = "dataSourceA")
public DataSource getDataSourceA() {
return dsA != null ? dsA : (dsA = new BasicDataSource());
}
#Bean(name = "dataSourceB")
public DataSource getDataSourceB() {
return dsB != null ? dsB : (dsB = new BasicDataSource());
}
#Bean(name = "sqlSessionFactoryA")
public SqlSessionFactory getSqlSessionFactoryA() throws Exception {
// set DataSource to dsA
return new SqlSessionFactoryBean().getObject();
}
#Bean(name = "sqlSessionFactoryB")
public SqlSessionFactory getSqlSessionFactoryB() throws Exception {
// set DataSource to dsB
return new SqlSessionFactoryBean().getObject();
}
}
#Repository
public class SimpleDao extends SqlSessionDaoSupport {
#Resource(name = "sqlSessionFactoryA")
SqlSessionFactory factory;
#PostConstruct
public void init() {
setSqlSessionFactory(factory);
}
#Override
public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
super.setSqlSessionFactory(sqlSessionFactory);
}
public <T> T get (Object id) {
return super.getSqlSession().selectOne("sql statement", "sql parameters");
}
}
In the end, we put each mapper in its own folder:
src/main/java/io/woolford/database/mapper/a/DbMapperA.java
src/main/java/io/woolford/database/mapper/c/DbMapperB.java
We then created two DataConfig classes, one for each database. The #MapperScan annotation resolved the expected single matching bean but found 2 issue.
#Configuration
#MapperScan(value = {"io.woolford.database.mapper.a"}, sqlSessionFactoryRef="sqlSessionFactoryA")
public class DataConfigDatabaseA {
It was necessary to add the #Primary annotation to the beans in one of the DataConfig classes:
#Bean(name="dataSourceA")
#Primary
public DataSource dataSourceA() throws SQLException {
...
}
#Bean(name="sqlSessionFactoryA")
#Primary
public SqlSessionFactory sqlSessionFactoryA() throws Exception {
...
}
Thanks to everyone who helped. No doubt, there's more than one way to do this. I did try #Qualifier and #EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class}) as recommended by #eduardlofitskyi and #GeminiKeith, but that generated some further errors.
In case it's useful, the solution that worked for us is posted here: https://github.com/alexwoolford/mybatis-spring-multiple-mysql-reproducible-example
You can use #Qualifier annotation
The problem is that you have two the same type beans in Spring container. And when you try autowire beans, Spring cannot resolve which bean inject to field
The #Qualifier annotation is the main way to work with qualifiers. It can be applied alongside #Autowired or #Inject at the point of injection to specify which bean you want to be injected.
So, your DbService should look like this:
#Service
public class DbService {
#Autowired
#Qualifier("dataSourceA")
private DbMapperA dbMapperA;
#Autowired
#Qualifier("dataSourceB")
private DbMapperB dbMapperB;
public List<Record> getDabaseARecords(){
return dbMapperA.getDatabaseARecords();
}
public List<Record> getDabaseBRecords(){
return dbMapperB.getDatabaseBRecords();
}
}
I had the same issue and could not start my Spring Boot application, and by renaming the offending class and all the layers that dealt with it, strangely the application started successfully.
I have the classes UOMService, UOMServiceImpl UOMRepository and UOMRepositoryImpl. I renamed them to be UomService, UomServiceImpl, UomRepository and UomRepositoryImpl and that solved the problem!

How to instantiate Spring managed beans at runtime?

I stuck with a simple refactoring from plain Java to Spring. Application has a "Container" object which instantiates its parts at runtime. Let me explain with the code:
public class Container {
private List<RuntimeBean> runtimeBeans = new ArrayList<RuntimeBean>();
public void load() {
// repeated several times depending on external data/environment
RuntimeBean beanRuntime = createRuntimeBean();
runtimeBeans.add(beanRuntime);
}
public RuntimeBean createRuntimeBean() {
// should create bean which internally can have some
// spring annotations or in other words
// should be managed by spring
}
}
Basically, during load container asks some external system to provide him information about number and configuration of each RuntimeBean and then it create beans according to given spec.
The problem is: usually when we do in Spring
ApplicationContext context = new AnnotationConfigApplicationContext(ApplicationConfiguration.class);
Container container = (Container) context.getBean("container");
our object is fully configured and have all dependencies injected. But in my case I have to instantiate some objects which also needs dependency injection after I execute load() method.
How can I achieve that?
I am using a Java-based config. I already tried making a factory for RuntimeBeans:
public class BeanRuntimeFactory {
#Bean
public RuntimeBean createRuntimeBean() {
return new RuntimeBean();
}
}
Expecting #Bean to work in so called 'lite' mode. http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/context/annotation/Bean.html Unfortunately, I found no difference with simply doing new RuntimeBean();
Here is a post with a similar issue: How to get beans created by FactoryBean spring managed?
There is also http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/beans/factory/annotation/Configurable.html but it looks like a hammer in my case.
I also tried ApplicationContext.getBean("runtimeBean", args) where runtimeBean has a "Prototype" scope, but getBean is an awful solution.
Update 1
To be more concrete I am trying to refactor this class:
https://github.com/apache/lucene-solr/blob/trunk/solr/core/src/java/org/apache/solr/core/CoreContainer.java
#see #load() method and find "return create(cd, false);"
Update 2
I found quite interesting thing called "lookup method injection" in spring documentation:
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/beans.html#beans-factory-lookup-method-injection
And also an interesting jira ticket https://jira.spring.io/browse/SPR-5192 where Phil Webb says https://jira.spring.io/browse/SPR-5192?focusedCommentId=86051&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-86051 that javax.inject.Provider should be used here (it reminds me Guice).
Update 3
There is also http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/beans/factory/config/ServiceLocatorFactoryBean.html
Update 4
The issue with all these 'lookup' methods is they don't support passing any arguments.. I also need to pass arguments as I would do with applicationContext.getBean("runtimeBean", arg1, arg2). Looks like it was fixed at some point with https://jira.spring.io/browse/SPR-7431
Update 5
Google Guice have a neat feature for it called AssistedInject. https://github.com/google/guice/wiki/AssistedInject
Looks like I found a solution. As I am using java based configuration it is even simpler than you can imagine. Alternative way in xml would be lookup-method, however only from spring version 4.1.X as it supports passing arguments to the method.
Here is a complete working example:
public class Container {
private List<RuntimeBean> runtimeBeans = new ArrayList<RuntimeBean>();
private RuntimeBeanFactory runtimeBeanFactory;
public void load() {
// repeated several times depending on external data/environment
runtimeBeans.add(createRuntimeBean("Some external info1"));
runtimeBeans.add(createRuntimeBean("Some external info2"));
}
public RuntimeBean createRuntimeBean(String info) {
// should create bean which internally can have some
// spring annotations or in other words
// should be managed by spring
return runtimeBeanFactory.createRuntimeBean(info);
}
public void setRuntimeBeanFactory(RuntimeBeanFactory runtimeBeanFactory) {
this.runtimeBeanFactory = runtimeBeanFactory;
}
}
public interface RuntimeBeanFactory {
RuntimeBean createRuntimeBean(String info);
}
//and finally
#Configuration
public class ApplicationConfiguration {
#Bean
Container container() {
Container container = new Container(beanToInject());
container.setBeanRuntimeFactory(runtimeBeanFactory());
return container;
}
// LOOK HOW IT IS SIMPLE IN THE JAVA CONFIGURATION
#Bean
public BeanRuntimeFactory runtimeBeanFactory() {
return new BeanRuntimeFactory() {
public RuntimeBean createRuntimeBean(String beanName) {
return runtimeBean(beanName);
}
};
}
#Bean
#Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
RuntimeBean runtimeBean(String beanName) {
return new RuntimeBean(beanName);
}
}
class RuntimeBean {
#Autowired
Container container;
}
That's it.
Thanks everyone.
i think that your concept is wrong by using
RuntimeBean beanRuntime = createRuntimeBean();
you are bypassing Spring container and resorting to using regular java constructor therefore any annotations on factory method are ignored and this bean is never managed by Spring
here is the solution to create multiple prototype beans in one method, not pretty looking but should work, I autowired container in RuntimeBean as proof of autowiring shown in log also you can see in log that every bean is new instance of prototype when you run this .
'
#Configuration
#ComponentScan
#EnableAutoConfiguration
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
ApplicationContext context = new AnnotationConfigApplicationContext(Application.class);
Container container = (Container) context.getBean("container");
container.load();
}
}
#Component
class Container {
private List<RuntimeBean> runtimeBeans = new ArrayList<RuntimeBean>();
#Autowired
ApplicationContext context;
#Autowired
private ObjectFactory<RuntimeBean> myBeanFactory;
public void load() {
// repeated several times depending on external data/environment
for (int i = 0; i < 10; i++) {
// **************************************
// COMENTED OUT THE WRONG STUFFF
// RuntimeBean beanRuntime = context.getBean(RuntimeBean.class);
// createRuntimeBean();
//
// **************************************
RuntimeBean beanRuntime = myBeanFactory.getObject();
runtimeBeans.add(beanRuntime);
System.out.println(beanRuntime + " " + beanRuntime.container);
}
}
#Bean
#Scope(BeanDefinition.SCOPE_PROTOTYPE)
public RuntimeBean createRuntimeBean() {
return new RuntimeBean();
}
}
// #Component
class RuntimeBean {
#Autowired
Container container;
} '
A simple approach:
#Component
public class RuntimeBeanBuilder {
#Autowired
private ApplicationContext applicationContext;
public MyObject load(String beanName, MyObject myObject) {
ConfigurableApplicationContext configContext = (ConfigurableApplicationContext) applicationContext;
SingletonBeanRegistry beanRegistry = configContext.getBeanFactory();
if (beanRegistry.containsSingleton(beanName)) {
return beanRegistry.getSingleton(beanName);
} else {
beanRegistry.registerSingleton(beanName, myObject);
return beanRegistry.getSingleton(beanName);
}
}
}
#Service
public MyService{
//inject your builder and create or load beans
#Autowired
private RuntimeBeanBuilder builder;
//do something
}
Instead of using SingletonBeanRegistry you can use this:
BeanFactory beanFactory = configContext.getBeanFactory();
Anyway SingletonBeanBuilder extends HierarchicalBeanFactory and HierarchicalBeanFactory extends BeanFactory
You don't need the Container because all of the runtime objects should be created, held and managed by ApplicationContext. Think about a web application, they are much the same. Each request contains external data/environment info as you mentioned above. What you need is a prototype/request scoped bean like ExternalData or EnvironmentInfo which can read and hold runtime data through a static way, let's say a static factory method.
<bean id="externalData" class="ExternalData"
factory-method="read" scope="prototype"></bean>
<bean id="environmentInfo" class="EnvironmentInfo"
factory-method="read" scope="prototype/singleton"></bean>
<bean class="RuntimeBean" scope="prototype">
<property name="externalData" ref="externalData">
<property name="environmentInfo" ref="environmentInfo">
</bean>
If you do need a container to save the runtime objects, code should be
class Container {
List list;
ApplicationContext context;//injected by spring if Container is not a prototype bean
public void load() {// no loop inside, each time call load() will load a runtime object
RuntimeBean bean = context.getBean(RuntimeBean.class); // see official doc
list.add(bean);// do whatever
}
}
Official doc Singleton beans with prototype-bean dependencies.
It is possible to register beans dynamically by using BeanFactoryPostProcesor. Here you can do that while the application is booting (spring's application context has been initialized). You can not register beans latest, but on the other hand, you can make use of dependency injection for your beans, as they become "true" Spring beans.
public class DynamicBeansRegistar implements BeanFactoryPostProcessor {
#Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
if (! (beanFactory instanceof BeanDefinitionRegistry)) {
throw new RuntimeException("BeanFactory is not instance of BeanDefinitionRegistry");
}
BeanDefinitionRegistry registry = (BeanDefinitionRegistry) beanFactory;
// here you can fire your logic to get definition for your beans at runtime and
// then register all beans you need (possibly inside a loop)
BeanDefinition dynamicBean = BeanDefinitionBuilder.
.rootBeanDefinition(TheClassOfYourDynamicBean.class) // here you define the class
.setScope(BeanDefinition.SCOPE_SINGLETON)
.addDependsOn("someOtherBean") // make sure all other needed beans are initialized
// you can set factory method, constructor args using other methods of this builder
.getBeanDefinition();
registry.registerBeanDefinition("your.bean.name", dynamicBean);
}
#Component
class SomeOtherClass {
// NOTE: it is possible to autowire the bean
#Autowired
private TheClassOfYourDynamicBean myDynamicBean;
}
As presented above, you can still utilize Spring's Dependency Injection, because the post processor works on the actual Application Context.

Defining the request scope as prototype for integration tests

When writing integration tests with Spring 3.1, I usually define the request scope to be a SimpleThreadScope, with the following XML context configuration:
<bean class="org.springframework.beans.factory.config.CustomScopeConfigurer">
<property name="scopes">
<map>
<entry key="request">
<bean class="org.springframework.context.support.SimpleThreadScope" />
</entry>
</map>
</property>
</bean>
To define the request scope to be backed by a prototype scope implementation, I thought to change the class to be an implementation of the prototype scope. However I was not able to locate any.
Looking at the Scope Interface Javadoc, in the section All Known Implementing Classes, I see listed: AbstractRequestAttributesScope, PortletContextScope, RequestScope, ServletContextScope, SessionScope, SimpleThreadScope... nothing that looks like a prototype scope.
How can I define the request scope as prototype for integration tests?
UPDATE: I've managed to make my integration tests pass by creating my own prototype scope, which I've defined as follow, so my question now is, whether the following implementation is correct, or it has to be fixed.
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.ObjectFactory;
import org.springframework.beans.factory.config.Scope;
public class PrototypeScope implements Scope {
private static final Log logger = LogFactory.getLog(PrototypeScope.class);
public Object get(String name, ObjectFactory objectFactory) {
return objectFactory.getObject();
}
public Object remove(String name) {
return null;
}
public void registerDestructionCallback(String name, Runnable callback) {
logger.warn("PrototypeScope does not support destruction callbacks. "
+ "Consider using a RequestScope in a Web environment.");
}
public Object resolveContextualObject(String key) {
return null;
}
public String getConversationId() {
return Thread.currentThread().getName();
}
}
UPDATE 2: I am using TestNG and my Integration tests look like this:
#Test
#ContextConfiguration(locations = { "classpath:META-INF/spring/test-context.xml" })
#TransactionConfiguration(transactionManager = "transactionManager", defaultRollback = true)
public class MyIntegrationTest extends AbstractTransactionalTestNGSpringContextTests {
#Resource
private MyBeanThatShouldBePrototype bean;
#Transactional
public void testCase() {
...
In fact it's working in a different way - Spring checks if bean is a prototype, and then clones its definition and just populate new bean, so there is no backing class for holding such beans. If you want to look at the implementation please visit:
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean and you will find:
if (mbd.isPrototype()) {
// It's a prototype -> create a new instance.
Object prototypeInstance = null;
try {
beforePrototypeCreation(beanName);
prototypeInstance = createBean(beanName, mbd, args);
}
finally {
afterPrototypeCreation(beanName);
}
bean = getObjectForBeanInstance(prototypeInstance, name, beanName, mbd);
}
If you want to use prototype scope in tests you can just manually create this bean by invoking new MyObjectThatShouldBePrototype() and then configure it as a Spring bean by using AutowireCapableBeanFactory (injected/autowired into your test):
#Autowired
AutowireCapableBeanFactory beanFactory;
public MyObjectThatShouldBePrototype getBean() {
MyObjectThatShouldBePrototype bean = new MyObjectThatShouldBePrototype();
beanFactory.autowireBean(bean);
return bean;
}
Of course there are several ways to create beans - you can find then here http://www.kubrynski.com/2013/09/injecting-spring-dependencies-into-non.html
Something like this is not working for you?
#Test
#ContextConfiguration(locations = { "classpath:META-INF/spring/test-context.xml" },
classes = MyIntegrationTest.TestConfig.class)
#TransactionConfiguration(transactionManager = "transactionManager", defaultRollback = true)
public class MyIntegrationTest extends AbstractTransactionalTestNGSpringContextTests {
#Resource
private MyBeanThatShouldBePrototype bean; // protype bean produced by spring
#Transactional
public void testCase() {
...
}
#Configuration
public static class TestConfig {
#Bean
#Scope(BeanDefinition.SCOPE_PROTOTYPE)
public MyBeanThatShouldBePrototype myBeanThatShouldBePrototype() {
return new MyBeanThatShouldBePrototype();
}
}
}
Probably you could go another way?
What about writing a beanfactorypostprocessor that changes the request scoped bean candidates to prototype instead?
I havent tried it myself but you should be able to apply this to any bean declared as request scoped and set the prototype flag.
In the spring context for your unit tests you define this processor and in the context for integration tests this postprocessor would not be around.

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