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@Component注解

默认注入的bean的id属性值为类名首字符小写

也可以在注入的时候指定id值

@Component()public class BeanAnnotation {    public void say(){        System.out.println("SAY SOMETHING!");    }}

BeanAnnotation annotation = (BeanAnnotation) applicationContext1.getBean("beanAnnotation");        annotation.say();

@Required注解

适用于bean属性的setter方法

表示该属性配置时必须被填充

public class BeanAnnotation {    private String name;    @Required    public void setName(String name) {        this.name = name;    }    public void say(){        System.out.println("SAY SOMETHING!");    }}

BeanAnnotation annotation = (BeanAnnotation) applicationContext1.getBean("beanAnnotation");        annotation.say();

否则会报错

Caused by: org.springframework.beans.factory.BeanInitializationException: Property 'name' is required for bean 'beanAnnotation'CapableBeanFactory.java:553)    ... 11 more

@Autowired注解

自动装配

可以用于bean的setter方法，构造器，构造函数

1.用在Field上

@Repositorypublic class AutoWiredDao {    public void say(){        System.out.println("Autowired....");    }}

@Servicepublic class AutoWiredServiceImpl implements AutoWiredService {
       @Autowired//加在bean上    private AutoWiredDao autoWiredDao;    @Override    public void say() {        autoWiredDao.say();    }}

2.加在setter方法上

@Autowired//加在setter方法上    public void setAutoWiredDao(AutoWiredDao autoWiredDao) {        this.autoWiredDao = autoWiredDao;    }

3.加在构造函数上

@Autowired//加在constructor上    public AutoWiredServiceImpl(AutoWiredDao autoWiredDao) {        this.autoWiredDao = autoWiredDao;    }

4.加在List上 把对象放入List

5.加在Map上 把Id和对象放入Map

使用@Oreder进行排序 只对List有效

/** * BeanInterface * 测试@Autowired注解List,Map,Set * Created by heqianqian on 2017/4/25. */public interface BeanInterface {
   }

/** * BeanImplOne * 测试@Autowired注解List,Map,Set * Created by heqianqian on 2017/4/25. */@Order(2)@Componentpublic class BeanImplOne implements BeanInterface {
   }

/** * BeanImplTwo * 测试@Autowired注解List,Map,Set * Created by heqianqian on 2017/4/25. */@Order(1)@Componentpublic class BeanImplTwo implements BeanInterface {
   }

@Componentpublic class BeanInvoker {    @Autowired    private List
   
     beanInterfaceList;    @Autowired    private Map
    
      beanInterfaceMap;    public void autowireList() {        System.out.println("===autowireList===");        if (null != beanInterfaceList) {            for (BeanInterface beanInterface : beanInterfaceList) {                System.out.println(beanInterface.getClass().getName());            }        } else {            System.out.println("beanInterfaceList is null");        }    }    public void autowireMap() {        System.out.println("===autowireMap===");        if (null != beanInterfaceMap) {            for (Map.Entry
     
       beanInterfaceEntry : beanInterfaceMap.entrySet()) {                System.out.println(beanInterfaceEntry.getKey() + " " + beanInterfaceEntry.getValue().getClass().getName());            }        } else {            System.out.println("beanInterfaceMap is null");        }    }}
     
    
   

BeanInvoker beanInvoker = (BeanInvoker) applicationContext1.getBean("beanInvoker");        beanInvoker.autowireList();        beanInvoker.autowireMap();

输出结果

===autowireList===  bean.annotation.BeanImplTwobean.annotation.BeanImplOne===autowireMap===beanImplOne bean.annotation.BeanImplOnebeanImplTwo bean.annotation.BeanImplTwo

@Qualifier注解

按类型装配多个可能bean实例的情况,可以缩小范围或者指定唯一bean，也可以用于指定构造器参数或者方法参数

可以注解集合类型变量

@Autowired    @Qualifier("beanImplOne")    private BeanInterface beanInterface;

public void qualifier(){        System.out.println("===qualifier===");        if (beanInterface!=null){            System.out.println(beanInterface.getClass().getName());        }    }

@Bean注解

@Bean+@Configuration

用于配置和初始化一个由SpringIoC容器管理的新对象的方法，类似于XML配置文件的<bean/>

@Configurationpublic class AppConfig {
       @Bean    public AutoWiredService myService(){        return new AutoWiredServiceImpl();    }}

等同于在XML文件中配置

bean没有指定name时默认id是方法的名称

@Bean+@Scope

@Bean默认的单例模式Singleton

使用@Scope的value属性指定作用域(singleton,prototype,request,session,global session)

proxyMode指定代理方式

@ImportResource，@PropertyResource和@Value注解

一般引入配置文件的方式

url=jdbc:mysql://localhost:3306/pro_managedriver=com.mysql.jdbc.Driverusername=rootpassword=root

使用注解引入配置文件的方法

public class MyDriverManager {    public MyDriverManager(String url, String driver, String username, String pwd) {        System.out.println("url:" + url);        System.out.println("driver:" + driver);        System.out.println("username:" + username);        System.out.println("pwd:" + pwd);    }}

@Configuration@PropertySource("classpath:jdbc.properties")public class AppConfig {
       @Value("${url}")    private String url;    @Value("${driver}")    private String driver;    @Value("${username}")    private String username;    @Value("${password}")    private String password;    @Bean    public MyDriverManager myDriverManager() {        return new MyDriverManager(url, driver, username, password);    }}

MyDriverManager myDriverManager = (MyDriverManager) applicationContext1.getBean("myDriverManager");        System.out.println(myDriverManager.getClass().getName());

输入结果

Loading XML bean definitions from class path resource [application-anno.xml]url:jdbc:mysql://localhost:3306/pro_managedriver:com.mysql.jdbc.Driverusername:heqianqianpwd:root===init StringStore===Disconnected from the target VM, address: '127.0.0.1:53370', transport: 'socket'bean.annotation.MyDriverManager

这里出现一个小问题

输入的username和配置文件的username不同 这里取到的是当前操作系统的用户名 所以建议修改配置文件 改成 数据库驱动.username的形式

jdbc.url=jdbc:mysql://localhost:3306/pro_managejdbc.driver=com.mysql.jdbc.Driverjdbc.username=rootjdbc.password=root

这样打印出来的结果就是正确的了

Loading XML bean definitions from class path resource [application-anno.xml]url:jdbc:mysql://localhost:3306/pro_managedriver:com.mysql.jdbc.Driverusername:rootpwd:root===init StringStore===bean.annotation.MyDriverManager

@Resource和@PostConstruct,@PreDestroy

没有显示指定name默认从属性名和setter方法得出

@Repositorypublic class ResouceDao {    public void save() {        System.out.println("ResouceDao Save");    }    @PostConstruct    public void init() {        System.out.println("ResouceDao Init");    }    @PreDestroy    public void destroy() {        System.out.println("ResouceDao Destroy");    }}

@Servicepublic class ResourceService {
       @Resource    private ResouceDao resouceDao;    //@Resource    //public void setResouceDao(ResouceDao resouceDao) {
       //    this.resouceDao = resouceDao;    //}    public void save() {        resouceDao.save();    }}

ResourceService resourceService = (ResourceService) applicationContext1.getBean("resourceService");        resourceService.save();

JSR330

首先引入jar包

      
    
     javax.inject
        
    
     javax.inject
        
    
     1
    
   

@Inject

等同于@AutoWired

可以用于构造器，Setters和类

@Named

与@Component等效

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