How to achieve applicationContext.xml effect with Spring annotations
Editor to share with you how to achieve Spring comments to achieve applicationContext.xml effect, I believe that most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to understand it!
Spring annotations-- achieving applicationContext.xml effect
With the increasing use of Springboot agile development, more annotations are used to configure Spring rather than Spring's applicationContext.xml files.
Configuration note: Spring is parsed to configuration class, which is equivalent to spring configuration file
Bean note: the container registers Bean components. The default id is the method name.
@ Configurationpublic class AppConfig {@ Bean public MyService myService () {return new MyServiceImpl ();}}
Equivalent to beans.xml file
1) applicationContext.xml file-package scan
@ ComponentScans (value = {@ ComponentScan (value = "com.self", excludeFilters = {@ Filter (type = FilterType.ANNOTATION,classes = {Controller.class})}) @ Configurationpublic class RootConfig {/ / Test Bean @ Bean public Person person () {return new Person ("Zhang Li", 22, "engineer");}}
2) Import properties file
PropertySource (value = {"classpath:person.properties"}) @ Configurationpublic class MainConfigOfProperty {@ Bean public Person person () {return new Person ();}}
Assignment
Public class Person {@ Value ("${person.name}") / / profile properties private String name;}
3) data source
@ EnableTransactionManagement// enables annotation-based transaction management @ ComponentScan ("com.self.ds") @ Configurationpublic class TxConfig {/ / data source @ Bean public DataSource dataSource () throws Exception {ComboPooledDataSource dataSource = new ComboPooledDataSource (); dataSource.setUser ("root"); dataSource.setPassword ("000111") DataSource.setDriverClass ("com.mysql.jdbc.Driver"); dataSource.setJdbcUrl ("jdbc:mysql://localhost:3306/self"); return dataSource;} @ Bean public JdbcTemplate jdbcTemplate () throws Exception {JdbcTemplate jdbcTemplate = new JdbcTemplate (dataSource ()); return jdbcTemplate } / / transaction Manager @ Bean public PlatformTransactionManager transactionManager () throws Exception {return new DataSourceTransactionManager (dataSource ());}}
Unit testing
Public class IOCTest {AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext (MainConfig.class); @ Test public void test02 () {Object bean1 = applicationContext.getBean ("person"); Object bean2 = applicationContext.getBean ("person"); System.out.println (bean1 = = bean2) } @ Test public void test01 () {Object bean = applicationContext.getBean ("person01"); System.out.println ("result:" + bean);} @ Test public void test () {String [] beanDefinitionNames = applicationContext.getBeanDefinitionNames () For (String beanDef:beanDefinitionNames) {System.out.println ("output:" + beanDef);}
Execution result
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