Java方式配置Spring

時間 2019-11-08

標籤 java 方式配置 spring 欄目 Java 简体版

原文原文鏈接

概述

　　本文主要講的是如何使用Java Bean來配置Spring，而不是用xml來配置Spring。java

　　本文主要是代碼，須要注意的都在註釋裏面。spring

Java配置Spring

 1 package com.wisely.highlight_spring4.ch1.javaconfig;
 2 
 3 /**
 4  * 最終被調用的類
 5  */
 6 public class FunctionService {
 7     public String sayHello(String word){
 8         return "Hello " + word +" !"; 
 9     }
10 }

 1 package com.wisely.highlight_spring4.ch1.javaconfig;
 2 
 3 /**
 4  * 調用類
 5  */
 6 public class UseFunctionService {
 7     //這裏也能夠使用@Autowired將FunctionService的實體bean注入到UseFunctionService中,
 8     //讓UseFunctionService具有將FunctionService的實體bean注入到UseFunctionService中的功能
 9     //@Autowired
10     FunctionService functionService;
11     
12     public void setFunctionService(FunctionService functionService) {
13         this.functionService = functionService;
14     }
15     
16     public String SayHello(String word){
17         return functionService.sayHello(word);
18     }
19 }

 1 package com.wisely.highlight_spring4.ch1.javaconfig;
 2 
 3 import org.springframework.context.annotation.Bean;
 4 import org.springframework.context.annotation.Configuration;
 5 
 6 /**
 7  * 配置類，代替xml配置
 8  */
 9 //聲明當前類是一個配置類
10 @Configuration
11 //自動掃描包名下全部使用@Service/@Component/@Repository和@Controller的類,並註冊爲Bean
12 //@ComponentScan("com.wisely.highlight_spring4.ch1")
13 public class JavaConfig {
14     /**
15      * 聲明當前方法的返回值是一個bean,bean的名稱是方法名
16      * @return bean
17      */
18     @Bean
19     public FunctionService functionService(){
20         return new FunctionService();
21     }
22     
23     @Bean 
24     public UseFunctionService useFunctionService(){
25         UseFunctionService useFunctionService = new UseFunctionService();
26         //注入FunctionService的時候直接調用functionService
27         useFunctionService.setFunctionService(functionService()); //3
28         return useFunctionService;
29         
30     }
31     /**
32      * 也能夠將bean做爲方法參數傳入,spring會自動注入
33      */
34 //    @Bean 
35 //    public UseFunctionService useFunctionService(FunctionService functionService){//4
36 //        UseFunctionService useFunctionService = new UseFunctionService();
37 //        useFunctionService.setFunctionService(functionService);
38 //        return useFunctionService;
39 //    }
40 }

 1 package com.wisely.highlight_spring4.ch1.javaconfig;
 2 
 3 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 4 
 5 /**
 6  * 程序入口
 7  */
 8 public class Main {
 9     public static void main(String[] args) {
10         //使用AnnotationConfigApplicationContext做爲容器,
11         //接受輸入一個配置類做爲參數
12         AnnotationConfigApplicationContext context =
13                 new AnnotationConfigApplicationContext(JavaConfig.class);
14         //得到聲明配置的UseFunctionService的Bean
15         UseFunctionService useFunctionService = context.getBean(UseFunctionService.class);
16         //調用輸出方法
17         System.out.println(useFunctionService.SayHello("java config"));
18         context.close();
19     }
20 }

　　最終效果以下所示spa

Java配置AOP

 1 package com.wisely.highlight_spring4.ch1.aop;
 2 
 3 import java.lang.annotation.Documented;
 4 import java.lang.annotation.ElementType;
 5 import java.lang.annotation.Retention;
 6 import java.lang.annotation.RetentionPolicy;
 7 import java.lang.annotation.Target;
 8 
 9 /**
10  * 攔截規則的註解
11  */
12 @Target(ElementType.METHOD)
13 @Retention(RetentionPolicy.RUNTIME)
14 @Documented
15 public @interface Action {
16     //註解參數
17     String name();
18 }

 1 package com.wisely.highlight_spring4.ch1.aop;
 2 
 3 import org.springframework.stereotype.Service;
 4 
 5 /**
 6  * 使用註解的被攔截類
 7  */
 8 @Service
 9 public class DemoAnnotationService {
10     @Action(name="註解式攔截的add操做")
11     public void add(){} 
12 }

 1 package com.wisely.highlight_spring4.ch1.aop;
 2 
 3 import org.springframework.stereotype.Service;
 4 
 5 /**
 6  * 使用方法規則被攔截類
 7  */
 8 @Service
 9 public class DemoMethodService {
10     public void add(){}
11 }

 1 package com.wisely.highlight_spring4.ch1.aop;
 2 
 3 import org.aspectj.lang.JoinPoint;
 4 import org.aspectj.lang.annotation.After;
 5 import org.aspectj.lang.annotation.Aspect;
 6 import org.aspectj.lang.annotation.Before;
 7 import org.aspectj.lang.annotation.Pointcut;
 8 import org.aspectj.lang.reflect.MethodSignature;
 9 import org.springframework.stereotype.Component;
10 
11 import java.lang.reflect.Method;
12 
13 /**
14  * 配置切面
15  */
16 @Aspect //聲明切面
17 @Component //讓切面成爲spring容器管理的bean
18 public class LogAspect {
19     //聲明切點,攔截Action
20     @Pointcut("@annotation(com.wisely.highlight_spring4.ch1.aop.Action)")
21     public void annotationPointCut() {
22     }
23 
24     //聲明建言,並使用@Pointcut定義的切點annotationPointCut()
25     @After("annotationPointCut()")
26     public void after(JoinPoint joinPoint) {
27         MethodSignature signature = (MethodSignature) joinPoint.getSignature();
28         Method method = signature.getMethod();
29         Action action = method.getAnnotation(Action.class);
30         //經過反射獲可得註解上的name屬性,而後作日誌記錄相關的操做
31         System.out.println("註解式攔截 " + action.name());
32     }
33 
34     //聲明建言,直接使用攔截規則做爲參數
35     @Before("execution(* com.wisely.highlight_spring4.ch1.aop.DemoMethodService.*(..))")
36     public void before(JoinPoint joinPoint) {
37         MethodSignature signature = (MethodSignature) joinPoint.getSignature();
38         Method method = signature.getMethod();
39         System.out.println("方法規則式攔截," + method.getName());
40     }
41 }

 1 package com.wisely.highlight_spring4.ch1.aop;
 2 
 3 import org.springframework.context.annotation.ComponentScan;
 4 import org.springframework.context.annotation.Configuration;
 5 import org.springframework.context.annotation.EnableAspectJAutoProxy;
 6 
 7 /**
 8  * Spring配置類,由於程序中使用了諸如@Service之類的配置,因此這裏不用寫其餘配置
 9  * 只須要使用@ComponentScan掃描一下就能夠了
10  */
11 @Configuration
12 //掃描註解,註冊bean
13 @ComponentScan("com.wisely.highlight_spring4.ch1.aop")
14 //開啓spring對AspectJ的支持
15 @EnableAspectJAutoProxy //1
16 public class AopConfig {
17 
18 }

 1 package com.wisely.highlight_spring4.ch1.aop;
 2 
 3 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 4 
 5 /**
 6  * 程序入口
 7  */
 8 public class Main {
 9     public static void main(String[] args) {
10          AnnotationConfigApplicationContext context =
11                     new AnnotationConfigApplicationContext(AopConfig.class);
12          DemoAnnotationService demoAnnotationService = context.getBean(DemoAnnotationService.class);
13          DemoMethodService demoMethodService = context.getBean(DemoMethodService.class);
14          demoAnnotationService.add();
15          demoMethodService.add();
16          context.close();
17     }
18 }