資訊專欄INFORMATION COLUMN
摘要：構(gòu)造函數(shù)方法進(jìn)行依賴注入注入的效率最高新建方法電源供電中。。。。。無參數(shù)構(gòu)造函數(shù)選創(chuàng)建有參的構(gòu)造函數(shù)有參數(shù)構(gòu)造函數(shù)多參數(shù)構(gòu)造函數(shù)。。。。
一、Spring基礎(chǔ) 1.Spring簡介 1.1 核心概念
| 序號(hào) | 概念 | 全稱 | 具體內(nèi)容 |
|---|---|---|---|
| 1 | IoC | Inversion of Control (控制反轉(zhuǎn)) | 對(duì)象創(chuàng)建和對(duì)象關(guān)系管理權(quán)限，由開發(fā)者轉(zhuǎn)為spring |
| 2 | DI | Dependency Injection(依賴注入) | 對(duì)象的依賴關(guān)系的創(chuàng)建過程 |
| 3 | AOP | Aspect Oriented Programming(面向切面編程) |
功能模塊組成：
| 模塊 | 功能 | 備注 |
|---|---|---|
| Core | IoC，DI 功能實(shí)現(xiàn)最基本實(shí)現(xiàn) | 核心模塊 |
| Beans | Bean工廠(創(chuàng)建對(duì)象的工廠) | 核心模塊 |
| Context | IoC容器，上下文 | 核心模塊 |
| SpEL | spring 表達(dá)式語言 | 核心模塊 |
| JDBC | JDBC封裝 | 數(shù)據(jù)訪問集成模塊 |
| ORM | 數(shù)據(jù)集成框架封裝，jpa jdo | 數(shù)據(jù)訪問集成模塊 |
| OXM | 實(shí)現(xiàn)對(duì)象和xml轉(zhuǎn)換 | 數(shù)據(jù)訪問集成模塊 |
| JMS | 生產(chǎn)消費(fèi)實(shí)現(xiàn) | 數(shù)據(jù)訪問集成模塊 |
| Transactions | 事務(wù)管理 | 數(shù)據(jù)訪問集成模塊 |
| web | web監(jiān)聽，初始化ioc容器，上傳等 | web模塊 |
| webSocket | webSocket開發(fā) | web模塊 |
| Servlet | spring MVC | web模塊 |
| Portlet | 內(nèi)容集成 聚合 | web模塊 |
| AOP | AOP相關(guān) | |
| Aspects | Aspects面向切面編程 | |
| Instrumentation | 設(shè)備相關(guān) | |
| Messaging | 消息相關(guān) | |
| Test | 測(cè)試模塊 |
spring 包含spring MVC
1.2 相關(guān)參數(shù)解析| 名稱 | 用途 | 備注 | 類型 |
|---|---|---|---|
| private | 聲明成員變量 | ||
| 有參的構(gòu)造函數(shù) | 關(guān)聯(lián)成員變量和無參構(gòu)造函數(shù)的關(guān)系 | ||
| public void play() | 構(gòu)造一個(gè)方法play，執(zhí)行具體邏輯 | ||
| @Autowired | 自動(dòng)滿足bean之間的依賴 | 自動(dòng)裝配，自動(dòng)注入注解 | 定義組件 |
| @Transactional | @Transactional 可以作用于接口、接口方法、類以及類方法上。當(dāng)作用于類上時(shí)，該類的所有 public 方法將都具有該類型的事務(wù)屬性，同時(shí)，我們也可以在方法級(jí)別使用該標(biāo)注來覆蓋類級(jí)別的定義。 但是 Spring 建議不要在接口或者接口方法上使用該注解，因?yàn)檫@只有在使用基于接口的代理時(shí)它才會(huì)生效。另外， @Transactional 注解應(yīng)該只被應(yīng)用到 public 方法上 | 事務(wù)管理 | |
| @Component | 表示這個(gè)累需要在應(yīng)用程序中被創(chuàng)建，被掃描 | 被spring上下文發(fā)現(xiàn)，自動(dòng)發(fā)現(xiàn)注解 | 定義組件 |
| @ComponentScanTransactional | 自動(dòng)發(fā)現(xiàn)應(yīng)用程序中創(chuàng)建的類 | 自動(dòng)掃描Component類 | 定義配置 |
| @Configuration | 表示當(dāng)前類是一個(gè)配置類 | 標(biāo)注類為配置類 | 定義配置 |
| @Test | 表示當(dāng)前類是一個(gè)測(cè)試類 | ||
| @RunWith(SpringJUnit4ClassRunner.class) | 引入Spring單元測(cè)試模塊 | 聲明使用SpringJUnit4ClassRunner.class 測(cè)試單元 | spring測(cè)試環(huán)境 |
| @ContextConfiguration(classes = AppConfig.class) | 加載配置類 | spring測(cè)試環(huán)境 | |
| @Primary | 首選bean | 設(shè)置實(shí)現(xiàn)類的首選 | 自動(dòng)裝配歧義性 |
| @Qualifier | 給bean做注解 | 調(diào)用的時(shí)候可以通過注解區(qū)分實(shí)現(xiàn)類 | 自動(dòng)裝配歧義性 |
| @Resource | @Resource 相當(dāng)于@Autowired + @Qualifier("userServiceNormal") | java標(biāo)準(zhǔn) | 自動(dòng)裝配歧義性 |
| @Repository | 標(biāo)注數(shù)據(jù)dao實(shí)現(xiàn)類 | 本質(zhì)和@Component沒有區(qū)別，只是更加明確 | 分層架構(gòu)中定義組件 |
| @Service | 標(biāo)注Service實(shí)現(xiàn)類 | 本質(zhì)和@Component沒有區(qū)別，只是更加明確 | 分層架構(gòu)中定義組件 |
| @Controller | 標(biāo)注web、controller實(shí)現(xiàn)類， API接口 | 本質(zhì)和@Component沒有區(qū)別，只是更加明確 | 分層架構(gòu)中定義組件 |
| @Bean | 當(dāng)前配置類為默認(rèn)配置類，自動(dòng)調(diào)用 | ||
| @Override | 重寫，重載 | 自雷重寫父類的方法 | |
| @RequestMapping | 是一個(gè)用來處理請(qǐng)求地址映射的注解，可用于類或方法上。用于類上，表示類中的所有響應(yīng)請(qǐng)求的方法都是以該地址作為父路徑。 | 配置url映射 | |
| @RestController | 是@ResponseBody和@Controller的組合注解 | ||
| Extends-繼承類 | 全盤繼承 | 在類的聲明中，通過關(guān)鍵字extends來創(chuàng)建一個(gè)類的子類。 | 對(duì)于class而言，Extends用于(單)繼承一個(gè)類（class） |
| implements-實(shí)現(xiàn)接口 | 給這個(gè)類附加額外的功能 | 實(shí)現(xiàn)接口就是在接口中定義了方法，這個(gè)方法要你自己去實(shí)現(xiàn)，接口可以看作一個(gè)標(biāo)準(zhǔn)，比如定義了一個(gè)動(dòng)物的接口，它里面有吃（eat()）這個(gè)方法，你就可以實(shí)現(xiàn)這個(gè)方法implements，這個(gè)方法是自己寫，可以是吃蘋果，吃梨子，香蕉，或者其他的。implements就是具體實(shí)現(xiàn)這個(gè)接口 | implements用于實(shí)現(xiàn)一個(gè)接口(interface) |
| DAO | DAO是傳統(tǒng)MVC中Model的關(guān)鍵角色，全稱是Data Access Object。DAO直接負(fù)責(zé)數(shù)據(jù)庫的存取工作，乍一看兩者非常類似，但從架構(gòu)設(shè)計(jì)上講兩者有著本質(zhì)的區(qū)別： | DAO則沒有擺脫數(shù)據(jù)的影子，仍然停留在數(shù)據(jù)操作的層面上，DAO則是相對(duì)數(shù)據(jù)庫而言 | |
| Repository | Repository蘊(yùn)含著真正的OO概念，即一個(gè)數(shù)據(jù)倉庫角色，負(fù)責(zé)所有對(duì)象的持久化管理。 | Repository是相對(duì)對(duì)象而言， | https://segmentfault.com/a/11... |
接口：
接口一般是只有方法聲明沒有定義的。
接口可以比作協(xié)議，比如我說一個(gè)協(xié)議是“殺人”那么這個(gè)接口你可以用 砍刀去實(shí)現(xiàn)，至于怎么殺砍刀可以去實(shí)現(xiàn)，當(dāng)然你也可以用搶來實(shí)現(xiàn)殺人接口，但是你不能用殺人接口去殺人，因?yàn)闅⑷私涌谥徊贿^是個(gè)功能說明，是個(gè)協(xié)議，具體怎么干，還要看他的實(shí)現(xiàn)類。那么一個(gè)包里面如果有接口，你可以不實(shí)現(xiàn)。這個(gè)不影響你使用其他類。
1.3 for 循環(huán)this.tracks.for + Enter 可以快速得到for循環(huán)
for (String track : this.tracks) {
System.out.println("音樂:" + track);
}
2.Component對(duì)象
2.1 創(chuàng)建maven項(xiàng)目
2.2 創(chuàng)建基礎(chǔ)目錄
2.3 配置pom.xml
4.0.0 com.xfedu spring01 1.0-SNAPSHOT org.springframework spring-context 4.3.13.RELEASE
2.4 編寫純java版本代碼
編寫MessagesService
package hello;
public class MessagesService {
/**
* 執(zhí)行打印功能
* @return返回要打印的字符串
*/
public String getMessage(){
return "hello world!";
}
}
編寫MessagePrinter
package hello;
public class MessagePrinter {
/**
* private 建立MessagePrinter 和 MessagesService 關(guān)聯(lián)關(guān)系
*/
private MessagesService service;
/**
* service setter 方法 選擇service 按住alt+insert 選擇setter
* 設(shè)置service的值
* @param service
*/
public void setService(MessagesService service) {
this.service = service;
}
public void printMessage(){
System.out.println(this.service.getMessage());
}
}
編寫Application
package hello;
/**
* 創(chuàng)建Application來調(diào)用MessagePrinter類
*/
public class Application {
public static void main(String[] args) {
System.out.println("application");
//創(chuàng)建打印機(jī)對(duì)象
MessagePrinter printer = new MessagePrinter();
//創(chuàng)建消息服務(wù)對(duì)象
MessagesService service = new MessagesService();
//設(shè)置打印機(jī)的service屬性
printer.setService(service);
//打印消息
printer.printMessage();
}
}
2.5 編寫spring 框架版本代碼
編寫MessagesService
package hello;
import org.springframework.stereotype.Component;
/**
* @Component通知spring容器,
* 應(yīng)用程序的對(duì)象(MessagesService)未來會(huì)通過spring容器自動(dòng)創(chuàng)建出來
* 不需要程序員通過new關(guān)鍵字來創(chuàng)建
*/
@Component
public class MessagesService {
/**
* ctrl+o 創(chuàng)建無參構(gòu)造的方法(object)
*
*/
public MessagesService() {
super();
System.out.println("MessageServer....");
}
/**
* 執(zhí)行打印功能
* @return返回要打印的字符串
*/
public String getMessage(){
return "hello world!";
}
}
編寫MessagePrinter
package hello;
import org.springframework.stereotype.Component;
/**
* @Component通知spring容器,
* 應(yīng)用程序的對(duì)象(MessagePrinter)未來會(huì)通過spring容器自動(dòng)創(chuàng)建出來
* 不需要程序員通過new關(guān)鍵字來創(chuàng)建
*/
@Component
public class MessagePrinter {
/**
* ctrl+o 創(chuàng)建無參構(gòu)造的方法(object)
*
*/
public MessagePrinter() {
super();
System.out.println("MessagePrinter");
}
/**
* private 建立MessagePrinter 和 MessagesService 關(guān)聯(lián)關(guān)系
*/
private MessagesService service;
/**
* service setter 方法 選擇service 按住alt+insert 選擇setter
* 設(shè)置service的值
* @param service
*/
public void setService(MessagesService service) {
this.service = service;
}
public void printMessage(){
System.out.println(this.service.getMessage());
}
}
編寫ApplicationSpring
package hello;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
/**
* 創(chuàng)建Application來調(diào)用MessagePrinter類
* @ComponentScan 掃描@Component注解的類
*/
@ComponentScan
public class ApplicationSpring {
public static void main(String[] args) {
System.out.println("application");
//
// //創(chuàng)建打印機(jī)對(duì)象
// MessagePrinter printer = new MessagePrinter();
// //創(chuàng)建消息服務(wù)對(duì)象
// MessagesService service = new MessagesService();
// //設(shè)置打印機(jī)的service屬性
// printer.setService(service);
//
// //打印消息
// printer.printMessage();
//初始化Spring容器
ApplicationContext context = new AnnotationConfigApplicationContext(ApplicationSpring.class);
}
}
優(yōu)點(diǎn)：通過 * @ComponentScan 掃描@Component注解的類，創(chuàng)建對(duì)象的時(shí)候就可以不用重新new
3.對(duì)象裝配注入Bean 3.1 Bena裝配(注入)的三種方式 3.1.1 隱式的bean發(fā)現(xiàn)機(jī)制和自動(dòng)裝配(主流)
package hello;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
/**
* 創(chuàng)建Application來調(diào)用MessagePrinter類
* @ComponentScan 掃描@Component注解的類
*/
@ComponentScan
public class ApplicationSpring {
public static void main(String[] args) {
System.out.println("application");
//
// //創(chuàng)建打印機(jī)對(duì)象
// MessagePrinter printer = new MessagePrinter();
// //創(chuàng)建消息服務(wù)對(duì)象
// MessagesService service = new MessagesService();
// //設(shè)置打印機(jī)的service屬性
// printer.setService(service);
//
// //打印消息
// printer.printMessage();
//初始化Spring容器
ApplicationContext context = new AnnotationConfigApplicationContext(ApplicationSpring.class);
//從容器中獲取MessagePrinter對(duì)象
MessagePrinter printer = context.getBean(MessagePrinter.class);
//從容器中獲取MessagesService對(duì)象
MessagesService service = context.getBean(MessagesService.class);
System.out.println(printer);
System.out.println(service);
//設(shè)置打印機(jī)的service屬性,printer和service 建立關(guān)聯(lián)關(guān)系
printer.setService(service);
//打印消息調(diào)用printMessage打印
printer.printMessage();
}
}
從Context中獲取class
ApplicationContext context = new AnnotationConfigApplicationContext(ApplicationSpring.class);
如何在對(duì)象中獲取對(duì)象
//從容器中獲取MessagePrinter對(duì)象,使用context.getBean方法 MessagePrinter printer = context.getBean(MessagePrinter.class);
如何建立對(duì)象的關(guān)聯(lián)關(guān)系
//設(shè)置打印機(jī)的service屬性,printer和service 建立關(guān)聯(lián)關(guān)系 printer.setService(service);
1.定義CompactDisc類，
內(nèi)置CompactDisc無參構(gòu)造函數(shù)
paly方法
用@Component包裝
2.定義CDPlayer
內(nèi)置CDPlayer無參數(shù)構(gòu)造函數(shù)
聲明CompactDisc
構(gòu)建有參構(gòu)造函數(shù)關(guān)聯(lián)CDPlayer和CompactDisc，利用@Autowired進(jìn)行關(guān)聯(lián)自動(dòng)管理
定義play方法
3.定義執(zhí)行main函數(shù)
先通過AnnotationConfigApplicationContext 查出類
執(zhí)行paly方法
利用@ComponentScan包裝，進(jìn)行自動(dòng)組件掃描
4.解耦組件掃描和主類
將注解和主類解耦，多帶帶新建配置類AppConfig
CompactDisc
package soundsystem;
import org.springframework.stereotype.Component;
@Component
public class CompactDisc {
public CompactDisc() {
super();
System.out.println("CompactDisc無參構(gòu)造函數(shù)");
}
public void play(){
System.out.println("正在播放音樂......");
}
}
CDPlayer
package soundsystem;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
/**
* Component 讓他能被spring上下文發(fā)現(xiàn)
*/
@Component
public class CDPlayer {
/**
*private 成員變量
*/
private CompactDisc cd;
public CDPlayer() {
super();
System.out.println("CDPlayer無參數(shù)構(gòu)造函數(shù)");
}
/**
* Ctrl + Insert 選(Constructor)創(chuàng)建有參的構(gòu)造函數(shù)
* @param
*/
@Autowired
public CDPlayer(CompactDisc cd) {
this.cd = cd;
System.out.println("CDPlayer有參數(shù)構(gòu)造函數(shù)");
}
/**
* 定義一個(gè)方法play,執(zhí)行cd.play()播放工作
*/
public void play(){
cd.play();
}
}
App
package soundsystem;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
@ComponentScan
public class App {
public static void main(String[] args) {
ApplicationContext context = new AnnotationConfigApplicationContext(App.class);
CDPlayer player = context.getBean(CDPlayer.class);
player.play();
}
}
將注解和主類解耦，多帶帶新建配置類AppConfig
AppConfig
這里就配置類掃描@ComponentScan 和@Configuration 注解
package soundsystem;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
/**
* 這就是一個(gè)配置類
*/
@Configuration
@ComponentScan
public class AppConfig {
public AppConfig() {
super();
System.out.println("配置類，用于將注解和主類解耦");
}
}
App
這里就將@ComponentScan注解取消了
package soundsystem;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class App {
public static void main(String[] args) {
ApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);
CDPlayer player = context.getBean(CDPlayer.class);
player.play();
}
}
3.1.2 在XML進(jìn)行顯示
applicationContext.xml
MessagePrinter
package hello;
/**
* @Component通知spring容器,
* 應(yīng)用程序的對(duì)象(MessagePrinter)未來會(huì)通過spring容器自動(dòng)創(chuàng)建出來
* 不需要程序員通過new關(guān)鍵字來創(chuàng)建
*/
public class MessagePrinter {
/**
* ctrl+o 創(chuàng)建無參構(gòu)造的方法(object)
*
*/
public MessagePrinter() {
super();
System.out.println("MessagePrinter");
}
/**
* private 建立MessagePrinter 和 MessagesService 關(guān)聯(lián)關(guān)系
*/
private MessagesService service;
/**
* service setter 方法 選擇service 按住alt+insert 選擇setter
* 設(shè)置service的值
* @param service
*/
public void setService(MessagesService service) {
this.service = service;
}
public void printMessage(){
System.out.println(this.service.getMessage());
}
}
MessagesService
package hello;
/**
* @Component通知spring容器,
* 應(yīng)用程序的對(duì)象(MessagesService)未來會(huì)通過spring容器自動(dòng)創(chuàng)建出來
* 不需要程序員通過new關(guān)鍵字來創(chuàng)建
*/
public class MessagesService {
/**
* ctrl+o 創(chuàng)建無參構(gòu)造的方法(object)
*
*/
public MessagesService() {
super();
System.out.println("MessageServer....");
}
/**
* 執(zhí)行打印功能
* @return返回要打印的字符串
*/
public String getMessage(){
return "hello world!";
}
}
ApplicationSpring
package hello;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* 創(chuàng)建Application來調(diào)用MessagePrinter類
* @ComponentScan 掃描@Component注解的類
*/
public class ApplicationSpring {
public static void main(String[] args) {
System.out.println("application");
//初始化Spring容器
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
//從容器中獲取MessagePrinter對(duì)象
MessagePrinter printer = context.getBean(MessagePrinter.class);
//打印消息調(diào)用printMessage打印
printer.printMessage();
}
}
聲明使用xml文件
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
3.1.3 在java中進(jìn)行顯示 3.2 Autowired 使用場(chǎng)景用于管理對(duì)象之間的關(guān)聯(lián)關(guān)系
3.2.1 簡單的依賴注入例子MessagePrinter
package hello;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
/**
* @Component通知spring容器,
* 應(yīng)用程序的對(duì)象(MessagePrinter)未來會(huì)通過spring容器自動(dòng)創(chuàng)建出來
* 不需要程序員通過new關(guān)鍵字來創(chuàng)建
*/
@Component
public class MessagePrinter {
/**
* ctrl+o 創(chuàng)建無參構(gòu)造的方法(object)
*
*/
public MessagePrinter() {
super();
System.out.println("MessagePrinter");
}
/**
* private 建立MessagePrinter 和 MessagesService 關(guān)聯(lián)關(guān)系
*/
private MessagesService service;
/**
* service setter 方法 選擇service 按住alt+insert 選擇setter
* 設(shè)置service的值
* @param service
* @Autowired 用于spring管理對(duì)象之間的關(guān)聯(lián)關(guān)系
*/
@Autowired
public void setService(MessagesService service) {
this.service = service;
}
public void printMessage(){
System.out.println(this.service.getMessage());
}
}
ApplicationSpring
package hello;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
/**
* 創(chuàng)建Application來調(diào)用MessagePrinter類
* @ComponentScan 掃描@Component注解的類
*/
@ComponentScan
public class ApplicationSpring {
public static void main(String[] args) {
System.out.println("application");
//
// //創(chuàng)建打印機(jī)對(duì)象
// MessagePrinter printer = new MessagePrinter();
// //創(chuàng)建消息服務(wù)對(duì)象
// MessagesService service = new MessagesService();
// //設(shè)置打印機(jī)的service屬性
// printer.setService(service);
//
// //打印消息
// printer.printMessage();
//初始化Spring容器
ApplicationContext context = new AnnotationConfigApplicationContext(ApplicationSpring.class);
//從容器中獲取MessagePrinter對(duì)象
MessagePrinter printer = context.getBean(MessagePrinter.class);
//從容器中獲取MessagesService對(duì)象
//MessagesService service = context.getBean(MessagesService.class);
//System.out.println(printer);
//System.out.println(service);
//設(shè)置打印機(jī)的service屬性,printer和service 建立關(guān)聯(lián)關(guān)系
//printer.setService(service);
//打印消息調(diào)用printMessage打印
printer.printMessage();
}
}
注解：使用@Autowired管理對(duì)象之間的關(guān)聯(lián)關(guān)系，這樣就可以自動(dòng)處理關(guān)聯(lián)關(guān)系。
3.2.2 構(gòu)造函數(shù)方法進(jìn)行依賴注入注入的效率最高
Power 新建power方法
package soundsystem;
import org.springframework.stereotype.Component;
@Component
public class Power {
public Power() {
super();
}
public void supply(){
System.out.println("電源供電中。。。。。");
}
}
CDPlayer 增加power注入
package soundsystem;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
/**
* Component 讓他能被spring上下文發(fā)現(xiàn)
*/
@Component
public class CDPlayer {
/**
*private 成員變量
*/
private CompactDisc cd;
private Power power;
public CDPlayer() {
super();
System.out.println("CDPlayer無參數(shù)構(gòu)造函數(shù)");
}
/**
* Ctrl + Insert 選(Constructor)創(chuàng)建有參的構(gòu)造函數(shù)
* @param
*/
// @Autowired
// public CDPlayer(CompactDisc cd, Power power) {
// this.cd = cd;
// this.power = power;
// System.out.println("CDPlayer多參數(shù)構(gòu)造函數(shù)");
// }
@Autowired
public CDPlayer(CompactDisc cd, Power power) {
this.cd = cd;
this.power = power;
System.out.println("CDPlayer多參數(shù)構(gòu)造函數(shù)。。。。");
}
/**
* 定義一個(gè)方法play,執(zhí)行cd.play() power.supply();播放工作
*/
public void play(){
power.supply();
cd.play();
}
}
CompactDisc 無修改
package soundsystem;
import org.springframework.stereotype.Component;
@Component
public class CompactDisc {
public CompactDisc() {
super();
System.out.println("CompactDisc無參構(gòu)造函數(shù)");
}
public void play(){
System.out.println("正在播放音樂......");
}
}
AppConfig 無修改
package soundsystem;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
/**
* 這就是一個(gè)配置類
*/
@Configuration
@ComponentScan
public class AppConfig {
public AppConfig() {
super();
System.out.println("配置類，用于將注解和主類解耦");
}
}
AppTest 無修改
package soundsystem;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = AppConfig.class)
public class AppTest {
@Autowired
private CDPlayer player;
@Test
public void testPlay(){
player.play();
}
}
3.2.3 用成員變量的方式進(jìn)行依賴注入
這個(gè)方式就是spring通過反射機(jī)制做的依賴注入
注入效率低，但是簡潔
package soundsystem;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
/**
* Component 讓他能被spring上下文發(fā)現(xiàn)
*/
@Component
public class CDPlayer {
/**
*private 成員變量
*/
@Autowired
private CompactDisc cd;
@Autowired
private Power power;
public CDPlayer() {
super();
System.out.println("CDPlayer無參數(shù)構(gòu)造函數(shù)");
}
/**
* Ctrl + Insert 選(Constructor)創(chuàng)建有參的構(gòu)造函數(shù)
* @param
*/
// @Autowired
// public CDPlayer(CompactDisc cd) {
// this.cd = cd;
// System.out.println("CDPlayer有參數(shù)構(gòu)造函數(shù)");
// }
// @Autowired
// public CDPlayer(CompactDisc cd, Power power) {
// this.cd = cd;
// this.power = power;
// System.out.println("CDPlayer多參數(shù)構(gòu)造函數(shù)。。。。");
// }
/**
* 定義一個(gè)方法play,執(zhí)行cd.play()播放工作
*/
public void play(){
power.supply();
cd.play();
}
}
3.2.3 利用setter方法進(jìn)行依賴注入
Alt+Insert 選setter進(jìn)行setter對(duì)對(duì)象方法進(jìn)行裝配
package soundsystem;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
/**
* Component 讓他能被spring上下文發(fā)現(xiàn)
*/
@Component
public class CDPlayer {
/**
*private 成員變量
*/
//@Autowired
private CompactDisc cd;
//@Autowired
private Power power;
@Autowired
public void setCd(CompactDisc cd) {
this.cd = cd;
System.out.println("調(diào)用setCd。。。。");
}
@Autowired
public void setPower(Power power) {
this.power = power;
System.out.println("調(diào)用setPower。。。");
}
public CDPlayer() {
super();
System.out.println("CDPlayer無參數(shù)構(gòu)造函數(shù)");
}
/**
* Ctrl + Insert 選(Constructor)創(chuàng)建有參的構(gòu)造函數(shù)
* @param
*/
// @Autowired
// public CDPlayer(CompactDisc cd) {
// this.cd = cd;
// System.out.println("CDPlayer有參數(shù)構(gòu)造函數(shù)");
// }
// @Autowired
// public CDPlayer(CompactDisc cd, Power power) {
// this.cd = cd;
// this.power = power;
// System.out.println("CDPlayer多參數(shù)構(gòu)造函數(shù)。。。。");
// }
/**
* 定義一個(gè)方法play,執(zhí)行cd.play()播放工作
*/
public void play(){
power.supply();
cd.play();
}
}
3.2.4 用在任意方法上
package soundsystem;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
/**
* Component 讓他能被spring上下文發(fā)現(xiàn)
*/
@Component
public class CDPlayer {
/**
*private 成員變量
*/
//@Autowired
private CompactDisc cd;
//@Autowired
private Power power;
// @Autowired
// public void setCd(CompactDisc cd) {
// this.cd = cd;
// System.out.println("調(diào)用setCd。。。。");
// }
//
// @Autowired
// public void setPower(Power power) {
// this.power = power;
// System.out.println("調(diào)用setPower。。。");
// }
@Autowired
public void prepare(CompactDisc cd ,Power power){
this.cd = cd;
this.power = power;
System.out.println("調(diào)用prepare。。。");
}
public CDPlayer() {
super();
System.out.println("CDPlayer無參數(shù)構(gòu)造函數(shù)");
}
/**
* Ctrl + Insert 選(Constructor)創(chuàng)建有參的構(gòu)造函數(shù)
* @param
*/
// @Autowired
// public CDPlayer(CompactDisc cd) {
// this.cd = cd;
// System.out.println("CDPlayer有參數(shù)構(gòu)造函數(shù)");
// }
// @Autowired
// public CDPlayer(CompactDisc cd, Power power) {
// this.cd = cd;
// this.power = power;
// System.out.println("CDPlayer多參數(shù)構(gòu)造函數(shù)。。。。");
// }
/**
* 定義一個(gè)方法play,執(zhí)行cd.play()播放工作
*/
public void play(){
power.supply();
cd.play();
}
}
4.接口開發(fā) interface
4.1 簡單的接口實(shí)現(xiàn)，單一實(shí)現(xiàn)類環(huán)境
創(chuàng)建com.cloud.demo.service 包
創(chuàng)建UserService 接口
package com.cloud.demo.service; /**
*/
public interface UserService {
void add();
}
- 創(chuàng)建接口實(shí)現(xiàn)方法(實(shí)現(xiàn)類)，創(chuàng)建包c(diǎn)om.cloud.demo.service.com.cloud.demo.service.impl，創(chuàng)建實(shí)現(xiàn)類UserServiceNormal
package com.cloud.demo.service.com.cloud.demo.service.impl;
import com.cloud.demo.service.UserService;
import org.springframework.stereotype.Component;
/**
UserServiceNormal 實(shí)現(xiàn)UserService 的方法
這里為實(shí)現(xiàn)類,@Component不寫在接口，寫在實(shí)現(xiàn)類上
*/
@Component
public class UserServiceNormal implements UserService {
public void add() {
System.out.println("添加用戶");
}
}
- 創(chuàng)建配置類AppConfig
package com.cloud.demo.service;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
@Configuration
@ComponentScan
public class AppConfig {
}
- 創(chuàng)建單元測(cè)試，新建包c(diǎn)om.cloud.demo.service，userService的接口UserServiceTest
package com.cloud.demo.service;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
/**
1.要測(cè)試的是userService的接口
2.private UserService userService; 接口注入@Autowired
3.userService.add() 調(diào)用add()方法
*/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = AppConfig.class)
public class UserServiceTest {
//單一實(shí)現(xiàn)類環(huán)境下
@Autowired
private UserService userService;
@Test
public void testAdd(){
userService.add();
}
}
***@Component不寫在接口，寫在實(shí)現(xiàn)類上*** ***調(diào)用userService，需要聲明接口 private UserService userService;*** ### 4.2 多實(shí)現(xiàn)類環(huán)境 #### 4.2.1 設(shè)置首選Bean - 配置@Primary，這樣系統(tǒng)默認(rèn)就會(huì)使用UserServiceNormal實(shí)現(xiàn)類，但是有局限性 - 只能定義一個(gè)@Primary
@Component
@Primary
public class UserServiceNormal implements UserService {
public void add() {
System.out.println("增加用戶");
}
public void del() {
System.out.println("刪除用戶");
}
}
#### 4.2.2 使用限定符@Qualifier UserServiceFestival
@Component
@Qualifier("Festival")
public class UserServiceFestival implements UserService {
@Override
public void add() {
System.out.println("注冊(cè)用戶并發(fā)送優(yōu)惠券");
}
@Override
public void del() {
}
}
UserServiceNormal
@Component
@Qualifier("Normal")
public class UserServiceNormal implements UserService {
public void add() {
System.out.println("增加用戶");
}
public void del() {
System.out.println("刪除用戶");
}
}
UserServiceTest
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = AppConfig.class)
public class UserServiceTest {
@Autowired
//這里通過@Qualifier 調(diào)用Festival 實(shí)現(xiàn)類
@Qualifier("Festival")
private UserService userService;
@Test
public void testAdd(){
userService.add();
userService.del();
}
}
#### 4.2.3 通過設(shè)置ID和限定符實(shí)現(xiàn) - 將參數(shù)配置在@Component中實(shí)現(xiàn)@Qualifier UserServiceFestival
@Component("fastival")
public class UserServiceFestival implements UserService {
@Override
public void add() {
System.out.println("注冊(cè)用戶并發(fā)送優(yōu)惠券");
}
@Override
public void del() {
}
}
UserServiceNormal
@Component("normal")
public class UserServiceNormal implements UserService {
public void add() {
System.out.println("增加用戶");
}
public void del() {
System.out.println("刪除用戶");
}
}
UserServiceTest
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = AppConfig.class)
public class UserServiceTest {
@Autowired
@Qualifier("fastival")
private UserService userService;
@Test
public void testAdd(){
userService.add();
userService.del();
}
}
#### 4.2.4 使用系統(tǒng)默認(rèn)ID和限定符 - spring中默認(rèn)會(huì)給實(shí)現(xiàn)類分配一個(gè)ID ,為類名首寫字母小寫 UserServiceTest
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = AppConfig.class)
public class UserServiceTest {
@Autowired
@Qualifier("userServiceNormal")
private UserService userService;
@Test
public void testAdd(){
userService.add();
userService.del();
}
}
#### 4.2.5 使用@Resource
- @Resource 相當(dāng)于@Autowired + @Qualifier("userServiceNormal")
- @Resource是jdk標(biāo)準(zhǔn)類，非spring標(biāo)準(zhǔn)類
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = AppConfig.class)
public class UserServiceTest {
//@Autowired
//@Qualifier("userServiceNormal")
@Resource(name="userServiceNormal")
private UserService userService;
@Test
public void testAdd(){
userService.add();
userService.del();
}
}
## 5.配置類 ComponentScan組件掃描 ### 5.1 直接聲明 直接聲明單個(gè)目錄
@Configuration
@ComponentScan("com.cloud.demo")
直接聲明多個(gè)目錄
@Configuration
@ComponentScan(basePackages = {"com.cloud.demo.web","com.cloud.demo.service","com.cloud.demo.dao"})
- 有風(fēng)險(xiǎn)重構(gòu)不會(huì)自動(dòng)修改 直接聲明接口類
@Configuration
@ComponentScan(basePackageClasses = {UserController.class, UserService.class, UserDao.class})
### 5.2 XML聲明 ***applicationContext.xml 相當(dāng)于@Configuration*** applicationContext.xml
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.xsd">
***測(cè)試用列中修改UserControllerTest***
@ContextConfiguration("classpath:applicationContext.xml") 指定xml位置
@RunWith(SpringJUnit4ClassRunner.class)
//@ContextConfiguration(classes = AppConfig.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class UserControllerTest {
@Autowired
private UserController userController;
@Test
public void testAdd(){
userController.add();
}
}
## 6 配置Java Configuration ### 6.1 如何配置@bean對(duì)象在java Config 接口：UserDao
public interface UserDao {
void add();
}
接口實(shí)現(xiàn)類：UserDaoNormal
public class UserDaoNormal implements UserDao {
@Override
public void add() {
System.out.println("添加用戶到數(shù)據(jù)庫中。。。。");
}
}
配置類：AppConfig - @Configuration 聲明為配置類 - @Bean標(biāo)識(shí)spring默認(rèn)啟動(dòng)會(huì)自動(dòng)加載改配置
@Configuration
public class AppConfig {
@Bean
public UserDao UserDaoNormal(){
System.out.println("創(chuàng)建UserDao對(duì)象");
return new UserDaoNormal();
}
}
測(cè)試類：UserDaoTest
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = AppConfig.class)
public class UserDaoTest {
@Autowired
private UserDao userDao;
@Test
public void testAdd(){
userDao.add();
}
}
### 6.2 構(gòu)造函數(shù)注入場(chǎng)景- 普通方式 UserServiceNormal - 通過構(gòu)造函數(shù)關(guān)聯(lián)依賴
public class UserServiceNormal implements UserService {
private UserDao userDao;
//無參構(gòu)造函數(shù)
public UserServiceNormal() {
super();
}
//有參構(gòu)造函數(shù)
public UserServiceNormal(UserDao userDao) {
this.userDao = userDao;
}
@Override
public void add() {
userDao.add();
}
}
UserService
public interface UserService {
void add();
}
UserDao
public interface UserDao {
void add();
}
UserDaoNormal
public class UserDaoNormal implements UserDao {
@Override
public void add() {
System.out.println("添加用戶到數(shù)據(jù)庫中。。。。");
}
}
AppConfig
@Configuration
public class AppConfig {
@Bean
public UserDao userDaoNormal(){
System.out.println("創(chuàng)建UserDao對(duì)象");
return new UserDaoNormal();
}
@Bean
public UserService userServiceNormal(){
System.out.println("創(chuàng)建UserService對(duì)象");
UserDao userDao = userDaoNormal();
return new UserServiceNormal(userDao);
}
}
UserServiceTest
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = AppConfig.class)
public class UserServiceTest {
@Autowired
private UserService userService;
@Test
public void testAdd(){
userService.add();
}
}
### 6.3 構(gòu)造函數(shù)注入場(chǎng)景- 優(yōu)雅方式 AppConfig
@Configuration
public class AppConfig {
@Bean
public UserDao userDaoNormal(){
System.out.println("創(chuàng)建UserDao對(duì)象");
return new UserDaoNormal();
}
@Bean
public UserService userServiceNormal(UserDao userDao){
System.out.println("創(chuàng)建UserService對(duì)象");
//UserDao userDao = userDaoNormal();
return new UserServiceNormal(userDao);
}
}
- 實(shí)際編程中不會(huì)做函數(shù)的調(diào)用，而是在參數(shù)中取獲取UserDao ### 6.4 通過setter方法依賴注入 UserServiceNormal
public class UserServiceNormal implements UserService {
private UserDao userDao;
//setter方法注入
public void setUserDao(UserDao userDao) {
this.userDao = userDao;
}
@Override
public void add() {
userDao.add();
}
}
AppConfig
@Configuration
public class AppConfig {
@Bean
public UserDao userDaoNormal(){
System.out.println("創(chuàng)建UserDao對(duì)象");
return new UserDaoNormal();
}
@Bean
public UserService userServiceNormal(UserDao userDao){
System.out.println("創(chuàng)建UserService對(duì)象");
//賦值給一個(gè)變量userService
UserServiceNormal userService = new UserServiceNormal();
//調(diào)用userService的setter方法，將userDao注入
userService.setUserDao(userDao);
//返回userService
return userService;
}
}
### 6.5 通過任意函數(shù)注入 UserServiceNormal
public class UserServiceNormal implements UserService {
private UserDao userDao;
//任意函數(shù)注入
public void prepare(UserDao userDao){
this.userDao = userDao;
}
@Override
public void add() {
userDao.add();
}
}
AppConfig
@Configuration
public class AppConfig {
@Bean
public UserDao userDaoNormal(){
System.out.println("創(chuàng)建UserDao對(duì)象");
return new UserDaoNormal();
}
@Bean
public UserService userServiceNormal(UserDao userDao){
System.out.println("創(chuàng)建UserService對(duì)象");
UserServiceNormal userService = new UserServiceNormal();
//任意函數(shù)注入
userService.prepare(userDao);
return userService;
}
}
### 6.6 XML裝配 #### 6.6.1 創(chuàng)建xml配置規(guī)范 applicationContext.xml
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.xsd">
#### 6.6.2 xml定義第bean CompactDisc
public class CompactDisc {
public CompactDisc() {
super();
System.out.println("CompacDisc構(gòu)造函數(shù)。。。。" + this.toString());
}
public void play(){
System.out.println("播放CD音樂。。。。。" + this.toString());
}
}
ApplicationSpring
public class ApplicationSpring {
public static void main(String[] args) {
System.out.println("ApplicationSpring is running......");
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
//初始化cd
CompactDisc cd = context.getBean(CompactDisc.class);
//調(diào)用play方法
cd.play();
}
}
applicationContext.xml - xml 定義bean
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.xsd">
輸出結(jié)果
ApplicationSpring is running......
CompacDisc構(gòu)造函數(shù)。。。。com.cloud.deam.soundsystem.CompactDisc@2669b199
播放CD音樂。。。。。com.cloud.deam.soundsystem.CompactDisc@2669b199
***多個(gè)重名bean設(shè)置id區(qū)分：***
- name可以通過分號(hào)、空格、逗號(hào)分隔，設(shè)置不同的別名 name="CompactDisc1 CompactDisc12 CompactDisc13 " - id只能通過傳字符進(jìn)行傳遞 ApplicationSpring -- 主方法
public class ApplicationSpring {
public static void main(String[] args) {
System.out.println("ApplicationSpring is running......");
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
//CompactDisc cd = context.getBean(CompactDisc.class);
CompactDisc cd1 = (CompactDisc) context.getBean("compactDisc1");
CompactDisc cd2 = (CompactDisc) context.getBean("compactDisc2");
cd1.play();
cd2.play();
}
}
AppTest -- 測(cè)試類
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class CompactDiscTest {
@Autowired
private CompactDisc CompactDisc1;
@Autowired
private CompactDisc CompactDisc2;
//過濾方式注入
@Autowired
@Qualifier("CompactDisc2")
private CompactDisc cd;
@Test
public void testPlay(){
CompactDisc1.play();
CompactDisc2.play();
cd.play();
}
}
#### 6.6.3 xml注入 - 通過構(gòu)造函數(shù) | 名稱 | 用途 | 備注 | | --------------------- | ------------------------------------------------------------ | ---- | |元素 | 依賴Bean，有參構(gòu)造函數(shù)依賴注入 | | | c-名稱空間 | --c：c函數(shù)命令空間 :cd 構(gòu)造函數(shù)的參數(shù)名字cd
public CDPlayer(CompactDisc cd)，-ref:表示的是CompactDisc2名稱的引用
也可以寫成c:0-ref="CompactDisc2" c:1-ref="CompactDisc2" 表示第一個(gè) 第二個(gè)參數(shù) | | | | | | ***元構(gòu)造函數(shù)依賴注入*** applicationContext.xml
CDPlayerTest
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class CDPlayerTest {
@Autowired
private CDPlayer cdPlayer;
@Test
public void Test01(){
cdPlayer.play();
}
}
***c-名稱空間依賴注入***
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:c="http://www.springframework.org/schema/c"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
CDPlayerTest
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class CDPlayerTest {
@Autowired
private CDPlayer cdPlayer1;
@Autowired
private CDPlayer cdPlayer2;
@Test
public void Test01(){
cdPlayer1.play();
cdPlayer2.play();
}
}
#### 6.6.4 注入簡單類型 -通過構(gòu)造函數(shù) - 給CompactDisc1 對(duì)象注入title、artist
***-c方式注入簡單類型：***
CompactDisc
public class CompactDisc {
private String title;
private String artist;
public CompactDisc() {
super();
System.out.println("CompacDisc構(gòu)造函數(shù)。。。。" + this.toString());
}
public CompactDisc(String title, String artist) {
this.title = title;
this.artist = artist;
System.out.println("CompacDisc構(gòu)造函數(shù)。。。。" + this.toString());
}
public void play(){
System.out.println("播放CD音樂。。。。。" + this.toString() +" " +this.title+ " by " +this.artist);
}
}
#### 6.6.5 注入list類型 -通過構(gòu)造函數(shù) applicationContext.xml
I Do 1 I Do 2 I Do 3
CompactDisc
public class CompactDisc {
private String title; private String artist; //聲明一個(gè)list private Listtracks; public CompactDisc() { super(); System.out.println("CompacDisc構(gòu)造函數(shù)。。。。" + this.toString()); } public CompactDisc(String title, String artist) { this.title = title; this.artist = artist; System.out.println("CompacDisc有參構(gòu)造函數(shù)。。。。" + this.toString()); } //創(chuàng)建包含三個(gè)函數(shù)的構(gòu)造函數(shù) public CompactDisc(String title, String artist, List tracks) { this.title = title; this.artist = artist; this.tracks = tracks; System.out.println("CompacDisc有三個(gè)參構(gòu)造函數(shù)。。。。" + this.toString()); } public void play(){ System.out.println("播放CD音樂。。。。。" + this.toString() +" " +this.title+ " by " +this.artist); //循環(huán)打印tracks內(nèi)容 for (String track : this.tracks) { System.out.println("音樂:" + track); } }
}
***創(chuàng)建一個(gè)復(fù)雜對(duì)象類型*** 創(chuàng)建類型 Music
package com.cloud.deam.soundsystem;
public class Music {
private String title;
private Integer duration;
//創(chuàng)建getter setter 方法
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public Integer getDuration() {
return duration;
}
public void setDuration(Integer duration) {
this.duration = duration;
}
//創(chuàng)建無參構(gòu)造方法
public Music() {
super();
}
//創(chuàng)建有參構(gòu)造方法
public Music(String title, Integer duration) {
this.title = title;
this.duration = duration;
}
}
CompactDisc
public class CompactDisc {
private String title; private String artist; //設(shè)置List為Music類型 private Listtracks; public CompactDisc() { super(); System.out.println("CompacDisc構(gòu)造函數(shù)。。。。" + this.toString()); } public CompactDisc(String title, String artist) { this.title = title; this.artist = artist; System.out.println("CompacDisc有參構(gòu)造函數(shù)。。。。" + this.toString()); } //設(shè)置List為Music類型 public CompactDisc(String title, String artist, List tracks) { this.title = title; this.artist = artist; this.tracks = tracks; System.out.println("CompacDisc有三個(gè)參構(gòu)造函數(shù)。。。。" + this.toString()); } public void play(){ System.out.println("播放CD音樂。。。。。" + this.toString() +" " +this.title+ " by " +this.artist); for (Music track : this.tracks) { //通過get方法獲取屬性 System.out.println("音樂:" + track.getTitle() + ".時(shí)長：" + track.getDuration()); } }
}
applicationContext.xml - 復(fù)雜的對(duì)象依賴注入
#### 6.6.6 注入set類型 -通過構(gòu)造函數(shù) CompactDisc
public class CompactDisc {
private String title; private String artist; //設(shè)置set為Music類型 private Listtracks; public CompactDisc() { super(); System.out.println("CompacDisc構(gòu)造函數(shù)。。。。" + this.toString()); } public CompactDisc(String title, String artist) { this.title = title; this.artist = artist; System.out.println("CompacDisc有參構(gòu)造函數(shù)。。。。" + this.toString()); } //設(shè)置set為Music類型 public CompactDisc(String title, String artist, set tracks) { this.title = title; this.artist = artist; this.tracks = tracks; System.out.println("CompacDisc有三個(gè)參構(gòu)造函數(shù)。。。。" + this.toString()); } public void play(){ System.out.println("播放CD音樂。。。。。" + this.toString() +" " +this.title+ " by " +this.artist); for (Music track : this.tracks) { //通過get方法獲取屬性 System.out.println("音樂:" + track.getTitle() + ".時(shí)長：" + track.getDuration()); } }
}
applicationContext.xml
- ***set和list區(qū)別在裝配的時(shí)候重復(fù)的值在set中會(huì)被過濾*** - ***set元素的順序能夠和插入一致。而list是無序的*** #### 6.6.7 注入MAP集合 -通過構(gòu)造函數(shù) CompactDisc
public class CompactDisc {
