Spring使用Value注解给Bean赋值-----Spring框架

太过爱你忘了你带给我的痛 2024-03-23 22:10 34阅读 0赞

>     package com.powernode.spring6.bean1;
>     
>     import org.springframework.beans.factory.annotation.Value;
>     import org.springframework.stereotype.Component;
>     
>     @Component
>     public class User
>     {
>     //    @Value("隔壁老王")
>         private String name;
>     //    @Value("30")
>         private int age;
>         //Value注解也可以用在方法上
>     //    @Value("隔壁老王")
>     //    public void setName(String name) {
>     //        this.name = name;
>     //    }
>     //    @Value("35")
>     //    public void setAge(int age) {
>     //        this.age = age;
>     //    }
>         public User(@Value("隔壁老王") String name, @Value("42") int age) {
>             this.name = name;
>             this.age = age;
>         }
>     
>         @Override
>         public String toString() {
>             return "User{" +
>                     "name='" + name + '\'' +
>                     ", age=" + age +
>                     '}';
>         }
>     }
> 
> package com.powernode.spring6.bean1;  
>   
> import org.springframework.beans.factory.annotation.Value;  
> import org.springframework.stereotype.Component;  
>   
> @Component  
> public class User  
> \{  
> // @Value("隔壁老王")  
> private String name;  
> // @Value("30")  
> private int age;  
> //Value注解也可以用在方法上  
> // @Value("隔壁老王")  
> // public void setName(String name) \{  
> // this.name = name;  
> // \}  
> // @Value("35")  
> // public void setAge(int age) \{  
> // this.age = age;  
> // \}  
> public User(@Value("隔壁老王") String name, @Value("42") int age) \{  
> this.name = name;  
> this.age = age;  
> \}  
>   
> @Override  
> public String toString() \{  
> return "User\{" +  
> "name='" + name + '\\'' +  
> ", age=" + age +  
> '\}';  
> \}  
> \}

>     package com.powernode.spring6.bean1;
>     
>     import org.springframework.beans.factory.annotation.Value;
>     import org.springframework.stereotype.Component;
>     
>     import javax.sql.DataSource;
>     import java.io.PrintWriter;
>     import java.sql.Connection;
>     import java.sql.SQLException;
>     import java.sql.SQLFeatureNotSupportedException;
>     import java.util.logging.Logger;
>     @Component
>     //先声明Bean,让Bean为Spring容器所管理
>     public class MyDataSource implements DataSource
>     {
>             @Value("com.mysql.jdbc.Driver")
>             private String driver;
>             @Value("jdbc:mysql://127.0.0.1:8080/mall")
>             private String url;
>             @Value("root")
>             private String username;
>             @Value("abc123")
>             private String password;
>     
>         @Override
>         public String toString() {
>             return "MyDataSource{" +
>                     "driver='" + driver + '\'' +
>                     ", url='" + url + '\'' +
>                     ", username='" + username + '\'' +
>                     ", password='" + password + '\'' +
>                     '}';
>         }
>     //    使用Value注解可以不提供Set方法,可以直接用在属性上
>     //    public void setDriver(String driver) {
>     //            this.driver = driver;
>     //        }
>     //
>     //        public void setUrl(String url) {
>     //            this.url = url;
>     //        }
>     //
>     //        public void setUsername(String username) {
>     //            this.username = username;
>     //        }
>     //
>     //        public void setPassword(String password) {
>     //            this.password = password;
>     //        }
>     
>             @Override
>             public Connection getConnection() throws SQLException {
>                 return null;
>             }
>     
>             @Override
>             public Connection getConnection(String username, String password) throws SQLException {
>                 return null;
>             }
>     
>             @Override
>             public PrintWriter getLogWriter() throws SQLException {
>                 return null;
>             }
>     
>             @Override
>             public void setLogWriter(PrintWriter out) throws SQLException {
>     
>             }
>     
>             @Override
>             public void setLoginTimeout(int seconds) throws SQLException {
>     
>             }
>     
>             @Override
>             public int getLoginTimeout() throws SQLException {
>                 return 0;
>             }
>     
>             @Override
>             public Logger getParentLogger() throws SQLFeatureNotSupportedException {
>                 return null;
>             }
>     
>             @Override
>             public <T> T unwrap(Class<T> iface) throws SQLException {
>                 return null;
>             }
>     
>             @Override
>             public boolean isWrapperFor(Class<?> iface) throws SQLException {
>                 return false;
>             }
>     }
> 
> package com.powernode.spring6.bean1;  
>   
> import org.springframework.beans.factory.annotation.Value;  
> import org.springframework.stereotype.Component;  
>   
> import javax.sql.DataSource;  
> import java.io.PrintWriter;  
> import java.sql.Connection;  
> import java.sql.SQLException;  
> import java.sql.SQLFeatureNotSupportedException;  
> import java.util.logging.Logger;  
> @Component  
> //先声明Bean,让Bean为Spring容器所管理  
> public class MyDataSource implements DataSource  
> \{  
> @Value("com.mysql.jdbc.Driver")  
> private String driver;  
> @Value("jdbc:mysql://127.0.0.1:8080/mall")  
> private String url;  
> @Value("root")  
> private String username;  
> @Value("abc123")  
> private String password;  
>   
> @Override  
> public String toString() \{  
> return "MyDataSource\{" +  
> "driver='" + driver + '\\'' +  
> ", url='" + url + '\\'' +  
> ", username='" + username + '\\'' +  
> ", password='" + password + '\\'' +  
> '\}';  
> \}  
> // 使用Value注解可以不提供Set方法,可以直接用在属性上  
> // public void setDriver(String driver) \{  
> // this.driver = driver;  
> // \}  
> //  
> // public void setUrl(String url) \{  
> // this.url = url;  
> // \}  
> //  
> // public void setUsername(String username) \{  
> // this.username = username;  
> // \}  
> //  
> // public void setPassword(String password) \{  
> // this.password = password;  
> // \}  
>   
> @Override  
> public Connection getConnection() throws SQLException \{  
> return null;  
> \}  
>   
> @Override  
> public Connection getConnection(String username, String password) throws SQLException \{  
> return null;  
> \}  
>   
> @Override  
> public PrintWriter getLogWriter() throws SQLException \{  
> return null;  
> \}  
>   
> @Override  
> public void setLogWriter(PrintWriter out) throws SQLException \{  
>   
> \}  
>   
> @Override  
> public void setLoginTimeout(int seconds) throws SQLException \{  
>   
> \}  
>   
> @Override  
> public int getLoginTimeout() throws SQLException \{  
> return 0;  
> \}  
>   
> @Override  
> public Logger getParentLogger() throws SQLFeatureNotSupportedException \{  
> return null;  
> \}  
>   
> @Override  
> public <T> T unwrap(Class<T> iface) throws SQLException \{  
> return null;  
> \}  
>   
> @Override  
> public boolean isWrapperFor(Class<?> iface) throws SQLException \{  
> return false;  
> \}  
> \}

>     <?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.xsd
>                                 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
>         <context:component-scan base-package="com.powernode.spring6.bean1" use-default-filters="true">
>     
>         </context:component-scan>
>     </beans>
> 
> <?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.xsd  
> http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">  
> <context:component-scan base-package="com.powernode.spring6.bean1" use-default-filters="true">  
>   
> </context:component-scan>  
> </beans>

>     package com.powernode.spring6.test;
>     
>     import com.powernode.spring6.bean1.MyDataSource;
>     import com.powernode.spring6.bean1.User;
>     import org.junit.Test;
>     import org.springframework.context.ApplicationContext;
>     import org.springframework.context.support.ClassPathXmlApplicationContext;
>     
>     public class TestAnnotation
>     {
>         @Test
>         public void TestAnnotation()
>         {
>             ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring.xml");
>         }
>         @Test
>         public void TestDIByAnnotation()
>         {
>             ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring-di.xml");
>             MyDataSource myDataSource = applicationContext.getBean("myDataSource", MyDataSource.class);
>             System.out.println(myDataSource);
>             User user = applicationContext.getBean("user", User.class);
>             System.out.println(user);
>         }
>     }
> 
> package com.powernode.spring6.test;  
>   
> import com.powernode.spring6.bean1.MyDataSource;  
> import com.powernode.spring6.bean1.User;  
> import org.junit.Test;  
> import org.springframework.context.ApplicationContext;  
> import org.springframework.context.support.ClassPathXmlApplicationContext;  
>   
> public class TestAnnotation  
> \{  
> @Test  
> public void TestAnnotation()  
> \{  
> ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring.xml");  
> \}  
> @Test  
> public void TestDIByAnnotation()  
> \{  
> ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring-di.xml");  
> MyDataSource myDataSource = applicationContext.getBean("myDataSource", MyDataSource.class);  
> System.out.println(myDataSource);  
> User user = applicationContext.getBean("user", User.class);  
> System.out.println(user);  
> \}  
> \}