spring4.0 之 @Configuration注解

叁歲伎倆 2022-01-09 18:35 179阅读 0赞

@Configuration注解与spring-\*.xml达到的目的是一样的。@Configuration是为了完全的取消xml配置文件而改用注解。下面将对其进行对比说明：

#### beans的加载方式 ####

spring-.xml的加载方式：ClassPathXmlApplicationContext、FileSystemXmlApplicationContext、ContextLoaderListener(用于WEB)；  
纯注解的加载方式:AnnotationConfigApplicationContext、AnnotationConfigWebApplicationContext(用于WEB)；

#### @Configuration与@Bean ####

xml配置：

<?xml version = "1.0" encoding = "UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd" 
         default-lazy-init="true" default-autowire="default">
    
        <bean id="student" class="com.demo.enity.Student" 
                      init-method="init" destroy-method="destroy" lazy-init="false">
            <property name="age" value="18"/>
            <property name="name" value="test"/>
        </bean>
    
    </beans>

public class Student {
        private Integer age;
        private String name;
    
        public void setAge(Integer age) {
            this.age = age;
        }
    
        public Integer getAge() {
            System.out.println("Age : " + age);
            return age;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public String getName() {
            System.out.println("Name : " + name);
            return name;
        }
    
        public void printThrowException() {
            System.out.println("Exception raised");
            throw new IllegalArgumentException();
        }
    
        public void init(){
            System.out.println("=============Student.init==============");
        }
    
        public void destroy(){
            System.out.println("=============Student.destroy==============");
        }
    }

ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring-bean.xml");
        Student student = context.getBean(Student.class);
        student.getName();
        student.getAge();

注解配置：

@Configuration
    @Lazy
    //@Profile("test")
    public class BeanConfiguration {
        @Bean(name = "student", initMethod = "init", destroyMethod = "destroy")
        @Scope("prototype")
        public Student student(){
            Student student = new Student();
            student.setAge(100);
            student.setName("this is a test name.");
            return student;
        }
    }

AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
            annotationConfigApplicationContext.register(BeanConfiguration.class);
            annotationConfigApplicationContext.refresh();
            Student student1 = annotationConfigApplicationContext.getBean(Student.class);
            student1.getName();
            student1.getAge();

半xml配置半注解:

@Configuration
    @Lazy
    //@Profile("test")
    public class BeanConfiguration {
    
        @Bean(name = "student", initMethod = "init", destroyMethod = "destroy")
        @Scope("prototype")
        public Student student(){
            Student student = new Student();
            student.setAge(100);
            student.setName("this is a test name.");
            return student;
        }
    }

ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring-application.xml");
            Student student2 = context.getBean(Student.class);
            student2.getName();
            student2.getAge();

#### @Configuration与@ComponentScan ####

xml配置：

@Component
    public class Teacher {
        private Integer age;
        private String name;
        private String id;
            。。。
    }

ClassPathXmlApplicationContext context4 = 
    new ClassPathXmlApplicationContext("classpath:spring-annotation-componentScan.xml");
    Teacher teacher4 = context4.getBean(Teacher.class);
    System.out.println("teacher4.hashCode = ["+teacher4.hashCode()+"]");

注解配置：

@Configuration
    @ComponentScan("com.demo")
    public class ComponentScanConfig {
    }

AnnotationConfigApplicationContext context5 = new AnnotationConfigApplicationContext();
            context5.register(ComponentScanConfig.class);
            context5.refresh();
            Teacher teacher5 = context5.getBean(Teacher.class);
            System.out.println("teacher5.hashCode = ["+teacher5.hashCode()+"]");

#### @Configuration与@PropertySource ####

jdbc.properties：

jdbc.url=jdbc:mysql://172.28.1.1:3306/test
    jdbc.username=test
    jdbc.password=123456
    jdbc.driverClassName=com.mysql.jdbc.Driver
    druid.initialSize=10
    druid.minIdle=5
    druid.maxActive=20
    druid.maxWait=60000
    druid.poolPreparedStatements=true
    druid.maxPoolPreparedStatementPerConnectionSize=33
    druid.timeBetweenEvictionRunsMillis=60000
    druid.minEvictableIdleTimeMillis=300000
    druid.validationQuery=select 1 from dual
    druid.testWhileIdle=true
    druid.testOnBorrow=false
    druid.testOnReturn=false
    druid.removeAbandoned=true
    druid.removeAbandonedTimeout=1800
    druid.logAbandoned=true
    druid.filters=stat,wall,slf4j
    druid.logSlowSql=true
    druid.loginUsername=test
    druid.loginPassword=123456

xml配置：

<?xml version = "1.0" encoding = "UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:context="http://www.springframework.org/schema/context"
           xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd">
    
        <context:property-placeholder ignore-unresolvable="true"  location="jdbc.properties" />
    
        
        <bean name="dataSource" class="com.alibaba.druid.pool.DruidDataSource"  
            init-method="init" destroy-method="close">
            <property name="url" value="${jdbc.url}" />
            <property name="driverClassName" value="${jdbc.driverClassName}" />
            <property name="username" value="${jdbc.username}" />
            <property name="password" value="${jdbc.password}" />
            
            <property name="initialSize" value="${druid.initialSize}" />
            
            <property name="maxActive" value="${druid.maxActive}" />
            
            <property name="minIdle" value="${druid.minIdle}" />
            
            <property name="maxWait" value="${druid.maxWait}" />
            <property name="poolPreparedStatements" value="${druid.poolPreparedStatements}" />
            <property name="maxPoolPreparedStatementPerConnectionSize" value="${druid.maxPoolPreparedStatementPerConnectionSize}" />
            
            <property name="validationQuery" value="${druid.validationQuery}" />
            <property name="testOnBorrow" value="${druid.testOnBorrow}" />
            <property name="testOnReturn" value="${druid.testOnReturn}" />
            <property name="testWhileIdle" value="${druid.testWhileIdle}" />
            
            <property name="timeBetweenEvictionRunsMillis" value="${druid.timeBetweenEvictionRunsMillis}" />
            
            <property name="minEvictableIdleTimeMillis" value="${druid.minEvictableIdleTimeMillis}" />
            
            <property name="removeAbandoned" value="${druid.removeAbandoned}" />
            
            <property name="removeAbandonedTimeout" value="${druid.removeAbandonedTimeout}" />
            
            <property name="logAbandoned" value="${druid.logAbandoned}" />
            
        </bean>
    </beans>

ClassPathXmlApplicationContext context6 = 
                    new ClassPathXmlApplicationContext("classpath:spring-data.xml");
            DataSource dataSource = context6.getBean(DataSource.class);
            DruidDataSource druidDataSource = (DruidDataSource) dataSource;
            System.out.println("url = [" + druidDataSource.getUrl() + "]");
            System.out.println("username = [" + druidDataSource.getUsername() + "]");

注解配置:

@Configuration
    @PropertySource("classpath:jdbc.properties")
    public class DruidJdbcConfig {
        @Value("${jdbc.url}")
        private String url;
        @Value("${jdbc.username}")
        private String username;
        @Value("${jdbc.password}")
        private String password;
        @Value("${jdbc.driverClassName}")
        private String driverClassName;
        @Value("${druid.initialSize}")
        private int initialSize;
        @Value("${druid.minIdle}")
        private int minIdle;
        @Value("${druid.maxActive}")
        private int maxActive;
        @Value("${druid.maxWait}")
        private int maxWait;
        @Value("${druid.timeBetweenEvictionRunsMillis}")
        private int timeBetweenEvictionRunsMillis;
        @Value("${druid.minEvictableIdleTimeMillis}")
        private int minEvictableIdleTimeMillis;
        @Value("${druid.validationQuery}")
        private String validationQuery;
        @Value("${druid.testWhileIdle}")
        private boolean testWhileIdle;
        @Value("${druid.testOnBorrow}")
        private boolean testOnBorrow;
        @Value("${druid.testOnReturn}")
        private boolean testOnReturn;
        @Value("${druid.removeAbandoned}")
        private boolean removeAbandoned;
        @Value("${druid.removeAbandonedTimeout}")
        private int removeAbandonedTimeout;
        @Value("${druid.logAbandoned}")
        private boolean logAbandoned;
        @Value("${druid.filters}")
        private String filters;
        @Value("${druid.logSlowSql}")
        private boolean logSlowSql;
        @Value("${druid.loginUsername}")
        private String loginUsername;
        @Value("${druid.loginPassword}")
        private String loginPassword;
    
    }

AnnotationConfigApplicationContext context7 = new AnnotationConfigApplicationContext();
            context7.register(DruidJdbcConfig.class);
            context7.refresh();
            DruidJdbcConfig druidJdbcConfig = context7.getBean(DruidJdbcConfig.class);
            System.out.println("url = [" + druidJdbcConfig.getUrl() + "]");
            System.out.println("username = [" + druidJdbcConfig.getUsername() + "]");

#### @Configuration与@Import ####

spring-application.xml

spring-data.xml

<?xml version = "1.0" encoding = "UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:context="http://www.springframework.org/schema/context"
           xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd">
    
         <context:property-placeholder ignore-unresolvable="true"  location="jdbc.properties" />
    
         
        <bean name="dataSource" class="com.alibaba.druid.pool.DruidDataSource" >
            <property name="url" value="${jdbc.url}" />
            <property name="driverClassName" value="${jdbc.driverClassName}" />
            <property name="username" value="${jdbc.username}" />
            <property name="password" value="${jdbc.password}" />
            
            <property name="initialSize" value="${druid.initialSize}" />
            
            <property name="maxActive" value="${druid.maxActive}" />
            
            <property name="minIdle" value="${druid.minIdle}" />
            
            <property name="maxWait" value="${druid.maxWait}" />
            <property name="poolPreparedStatements" value="${druid.poolPreparedStatements}" />
            <property name="maxPoolPreparedStatementPerConnectionSize" value="${druid.maxPoolPreparedStatementPerConnectionSize}" />
              
            <property name="validationQuery" value="${druid.validationQuery}" />
            <property name="testOnBorrow" value="${druid.testOnBorrow}" />
            <property name="testOnReturn" value="${druid.testOnReturn}" />
            <property name="testWhileIdle" value="${druid.testWhileIdle}" />
              
            <property name="timeBetweenEvictionRunsMillis" value="${druid.timeBetweenEvictionRunsMillis}" />
            
            <property name="minEvictableIdleTimeMillis" value="${druid.minEvictableIdleTimeMillis}" />
            
            <property name="removeAbandoned" value="${druid.removeAbandoned}" />
            
            <property name="removeAbandonedTimeout" value="${druid.removeAbandonedTimeout}" />
            
            <property name="logAbandoned" value="${druid.logAbandoned}" />
            </bean>
    </beans>

ClassPathXmlApplicationContext context8 = 
                    new ClassPathXmlApplicationContext("classpath:spring-application.xml");
            query(context8.getBean(DataSource.class));

注解配置:

@Configuration
    @Import(DruidJdbcConfig.class)
    public class DruidPoolConfig {
        private final static Logger LOGGER = LoggerFactory.getLogger(DruidPoolConfig.class);
        @Autowired
        private DruidJdbcConfig druidJdbcConfig;
    
        @Bean
        public DataSource dataSource(){
            DruidDataSource datasource = new DruidDataSource();
            datasource.setUrl(druidJdbcConfig.getUrl());
            datasource.setUsername(druidJdbcConfig.getUsername());
            datasource.setPassword(druidJdbcConfig.getPassword());
            datasource.setDriverClassName(druidJdbcConfig.getDriverClassName());
            datasource.setInitialSize(druidJdbcConfig.getInitialSize());
            datasource.setMinIdle(druidJdbcConfig.getMinIdle());
            datasource.setMaxActive(druidJdbcConfig.getMaxActive());
            datasource.setMaxWait(druidJdbcConfig.getMaxWait());
              datasource.setTimeBetweenEvictionRunsMillis(druidJdbcConfig.getTimeBetweenEvictionRunsMillis());
            datasource.setMinEvictableIdleTimeMillis(druidJdbcConfig.getMinEvictableIdleTimeMillis());
            datasource.setValidationQuery(druidJdbcConfig.getValidationQuery());
            datasource.setTestWhileIdle(druidJdbcConfig.isTestWhileIdle());
            datasource.setTestOnBorrow(druidJdbcConfig.isTestOnBorrow());
            datasource.setTestOnReturn(druidJdbcConfig.isTestOnReturn());
            datasource.setRemoveAbandoned(druidJdbcConfig.isRemoveAbandoned());
            datasource.setRemoveAbandonedTimeout(druidJdbcConfig.getRemoveAbandonedTimeout());
            datasource.setLogAbandoned(druidJdbcConfig.isLogAbandoned());
            try {
                datasource.setFilters(druidJdbcConfig.getFilters());
            } catch (SQLException e) {
                LOGGER.error("datasource.setFilters occur error.", e);
            }
            return datasource;
            }
    }

AnnotationConfigApplicationContext context9 = new AnnotationConfigApplicationContext();
            context9.register(DruidPoolConfig.class);
            context9.refresh();
            query(context9.getBean(DataSource.class));

public static void query(DataSource dataSource) throws SQLException {
            Connection connection = null;
            PreparedStatement preparedStatement = null;
            ResultSet resultSet = null;
            try {
                        connection = dataSource.getConnection();
                connection.setAutoCommit(false);
                String sql = "select id,`name`,mobile from t_agent_user where id = ?";
                preparedStatement = connection.prepareStatement(sql);
                preparedStatement.setInt(1, 6497);
                resultSet = preparedStatement.executeQuery();
                while (resultSet.next()){
                    int id = resultSet.getInt("id");
                    String name = resultSet.getString("name");
                    String mobile = resultSet.getString("mobile");
    
                    System.out.println("id = [" + id + "]");
                    System.out.println("name = [" + name + "]");
                    System.out.println("mobile = [" + mobile + "]");
                }
                } catch (SQLException e) {
                e.printStackTrace();
                if (connection != null)
                    connection.rollback();
            }finally {
                if (connection != null){
                    connection.commit();
                    connection.setAutoCommit(true);
                }
    
                if (resultSet != null)
                    resultSet.close();
                if (preparedStatement != null)
                    preparedStatement.close();
                if (connection != null)
                    connection.close();
            }
                }

#### @Configuration与@ImportResource ####

@Configuration
    @ImportResource("classpath:spring-data.xml")
    public class ImportResourceConfig {
    }

AnnotationConfigApplicationContext context10 = new AnnotationConfigApplicationContext();
            context10.register(ImportResourceConfig.class);
            context10.refresh();
            query(context10.getBean(DataSource.class));

参考：[https://www.cnblogs.com/duanxz/p/7493276.html][https_www.cnblogs.com_duanxz_p_7493276.html]

转载于:https://blog.51cto.com/881206524/2121660

[https_www.cnblogs.com_duanxz_p_7493276.html]: https://www.cnblogs.com/duanxz/p/7493276.html