关于Spring-IoC的简单使用参考：
spring ioc的简单实例及bean的作用域属性解析
1、通过set方法注入不同数据类型
测试类代码(set方式注入的属性一定要加set方法)
/**通过set方法注入示例*/public class IoC_By_Set {/**注入Integer类型参数*/private Integer id;/**注入String类型参数*/private String name;/**注入实体Bean*/private User user;/**注入数组*/private Object[] array;/**注入List集合*/private List<Object> list;/**注入Set集合*/private Set<Object> set;/**注入Map键值对*/private Map<Object, Object> map;/**注入properties类型*/private Properties properties;/**注入空字符串*/private String emptyValue;/**注入null值*/private String nullValue = "";/**检测注入的属性是否全部正确*/public Boolean checkAttr() {if(id == null) {return false;} else {System.out.println("id:" + id);}System.out.println("--------------------------");if(name == null) {return false;} else {System.out.println("name:" + name);}System.out.println("--------------------------");if(user == null) {return false;} else {System.out.println("Bean:" + user.getId() + "|" + user.getUserName() + "|" + user.getPassWord());}System.out.println("--------------------------");if(array == null) {return false;} else {System.out.println("array:");for (Object object : array) {System.out.println(object.toString());}}System.out.println("--------------------------");if(list == null) {return false;} else {System.out.println("list:");for (Object object : list) {System.out.println(object.toString());}}System.out.println("--------------------------");if(set == null) {return false;} else {System.out.println("set:");for (Object object : set) {System.out.println(object.toString());}}System.out.println("--------------------------");if(map == null) {return false;} else {Set<Entry<Object, Object>> set = map.entrySet();System.out.println("map:");for (Entry<Object, Object> entry : set) {System.out.println(entry.getKey() + "|" + entry.getValue());}}System.out.println("--------------------------");if(properties == null) {return false;} else {Set<Entry<Object, Object>> set = properties.entrySet();System.out.println("properties:");for (Entry<Object, Object> entry : set) {System.out.println(entry.getKey() + "|" + entry.getValue());}}System.out.println("--------------------------");if(!"".equals(emptyValue)) return false;System.out.println("--------------------------");if(!(null == nullValue)) return false;System.out.println("--------------------------");System.out.println("全部正确！！！");return true;}public void setId(Integer id) {this.id = id;}public void setName(String name) {this.name = name;}public void setUser(User user) {this.user = user;}public void setArray(Object[] array) {this.array = array;}public void setList(List<Object> list) {this.list = list;}public void setSet(Set<Object> set) {this.set = set;}public void setMap(Map<Object, Object> map) {this.map = map;}public void setProperties(Properties properties) {this.properties = properties;}public void setEmptyValue(String emptyValue) {this.emptyValue = emptyValue;}public void setNullValue(String nullValue) {this.nullValue = nullValue;}}applicationContext.xml配置
<!-- set方式注入 --> <bean id="ioC_By_Set"> <!-- 注入id属性 --> <property name="id" value="1"/> <!-- 使用<![CDATA[]]>标记处理XML特 殊字符 --> <property name="name"> <!-- 也可以使用P&G --> <value><![CDATA[P&G]]></value> </property> <!-- 定义内部Bean注入 --> <property name="user"> <bean> <property name="id" value="1"/> <property name="userName" value="内部Bean"/> <property name="passWord" value="233"/> </bean> </property> <!-- 注入数组类型 --> <property name="array"> <array> <!-- 定义数组元素 --> <value>array01</value> <value>array02</value> <value>array03</value> </array> </property> <!-- 注入List类型 --> <property name="list"> <list> <!-- 定义list中元素 --> <value>list01</value> <value>list02</value> <value>list03</value> </list> </property> <!-- 注入Set类型 --> <property name="set"> <set> <!-- 定义set中元素 --> <value>set01</value> <value>set02</value> <value>set03</value> </set> </property> <!-- 注入Map类型 --> <property name="map"> <map> <!-- 定义map中的键值对 --> <entry> <key> <value>mapKey01</value> </key> <value>mapValue01</value> </entry> <entry> <key> <value>mapKey02</value> </key> <value>mapValue02</value> </entry> </map> </property> <!-- 注入properties类型 --> <property name="properties"> <props> <!-- 定义properties中的键值对 --> <prop key="propKey1">propValue1</prop> <prop key="propKey2">propValue2</prop> </props> </property> <!-- 注入空字符串 --> <property name="emptyValue"> <value></value> </property> <!-- 注入null值 --> <property name="nullValue"> <null/> </property> </bean>
测试代码
public class IoC_Test {private ApplicationContext ctx;@Before public void load() {//读取applicationContext.xml配置文件ctx = new ClassPathXmlApplicationContext("applicationContext.xml");}@Test public void SetTest() {IoC_By_Set ioc = (IoC_By_Set) ctx.getBean("ioC_By_Set");ioc.checkAttr();}}控制台结果：
id:1--------------------------name:P&G--------------------------Bean:1|内部Bean|233--------------------------array:array01array02array03--------------------------list:list01list02list03--------------------------set:set01set02set03--------------------------map:mapKey01|mapValue01mapKey02|mapValue02--------------------------properties:propKey2|propValue2propKey1|propValue1------------------------------------------------------------------------------全部正确！！！
2、通过构造方法注入各种类型属性
注意：使用JDK1.8版本请将spring相关jar包升级到4.x版本以上,否则不兼容构造方法注入
测试类代码
/** 通过构造方法注入示例 */public class IoC_By_Constructor {private Integer id;private String name;private User user;private List<Object> list;public IoC_By_Constructor() {}public IoC_By_Constructor(Integer id, String name, User user, List<Object> list) {this.id = id;this.name = name;this.user = user;this.list = list;}/**检查是否注入成功*/public Boolean checkAttr() {if(id == null) {return false;} else {System.out.println("id:" + id);}System.out.println("----------------------------");if(name == null) {return false;} else {System.out.println("name:" + name);}System.out.println("----------------------------");if(user == null) {return false;} else {System.out.println("user:" + user.getId() + "|" + user.getUserName() + "|" + user.getPassWord());}System.out.println("----------------------------");if(list == null) {return false;} else {System.out.println("list:");for (Object object : list) {System.out.println(object.toString());}}System.out.println("----------------------------");System.out.println("全部正确！！！");return true;}}applicationContext.xml配置
<!-- 构造方法注入 演示几种类型--> <bean id="ioC_By_Constructor"> <!-- 注入Integer属性,可以选择使用index指定参数位置,也可以选择使用type指定参数类型 --> <constructor-arg index="0" value="1" type="java.lang.Integer"/> <!-- 注入字符串 --> <constructor-arg value="P&G"/> <!-- 注入对象 --> <constructor-arg> <!-- 内建对象 --> <bean> <constructor-arg value="1"/> <constructor-arg value="构造内部Bean"/> <constructor-arg value="666"/> </bean> </constructor-arg> <!-- 注入集合 --> <constructor-arg> <list> <value>list01</value> <value>list02</value> <value>list03</value> </list> </constructor-arg> </bean>
测试代码：
public class IoC_Test {private ApplicationContext ctx;@Before public void load() {//读取applicationContext.xml配置文件ctx = new ClassPathXmlApplicationContext("applicationContext.xml");}@Test public void constructorTest() {IoC_By_Constructor ioc = (IoC_By_Constructor) ctx.getBean("ioC_By_Constructor");ioc.checkAttr();}}控制台结果：
id:1----------------------------name:P&G----------------------------user:1|构造内部Bean|666----------------------------list:list01list02list03----------------------------全部正确！！！
3、自动注入(自动装配)
自动装配虽然能节省一些代码但是不推荐使用
测试类代码：
/**自动装配注入*/public class IoC_By_Auto {private User user;/**检查是否注入成功*/public Boolean checkAttr() {if(user == null) {return false;} else {System.out.println("user:" + user.getId() + "|" + user.getUserName() + "|" + user.getPassWord());}System.out.println("正确！！！");return true;}/**自动装配的属性需要设置set方法*/public void setUser(User user) {this.user = user;}}applicationContext.xml配置
<!-- 被自动装配获取的bean --> <bean id="user"> <property name="id" value="1"/> <property name="userName" value="自动装配"/> <property name="passWord" value="233"/> </bean> <!-- 自动装配的bean autowire:byName 根据类的属性名查找与之命名相同的id的bean进行装配 byType 根据类的属性类型查找唯一一个匹配类型的bean,如果有多个bean匹配则抛出异常 constructor 根据类的构造方法参数类型匹配对应的bean no 默认,表示不使用自动装配 default：由上级标签<beans>的default-autowire属性确定 --> <bean id="ioC_By_Auto" autowire="byName"></bean>
测试代码
public class IoC_Test {private ApplicationContext ctx;@Before public void load() {//读取applicationContext.xml配置文件ctx = new ClassPathXmlApplicationContext("applicationContext.xml");}@Test public void AutoTest() {IoC_By_Auto ioc = (IoC_By_Auto) ctx.getBean("ioC_By_Auto");ioc.checkAttr();}}控制台结果
user:1|自动装配|233正确！！！
以上使用的是byName模式,其他模式配置代码已经注明,不做测试。
4、使用P命名空间注入属性
测试类代码
/**使用P命名空间注入*/public class IoC_By_P {private Integer id;private String name;private User user;/**检查是否注入成功*/public Boolean checkAttr() {if(id == null) {return false;} else {System.out.println("id:" + id);}System.out.println("----------------------------");if(name == null) {return false;} else {System.out.println("name:" + name);}System.out.println("----------------------------");if(user == null) {return false;} else {System.out.println("user:" + user.getId() + "|" + user.getUserName() + "|" + user.getPassWord());}System.out.println("----------------------------");System.out.println("全部正确！！！");return true;}//使用P命名空间注入属性需要设置set方法public void setId(Integer id) {this.id = id;}public void setName(String name) {this.name = name;}public void setUser(User user) {this.user = user;}}applicationContext.xml配置
<!-- 使用P命名空间注入各种类型属性 --> <bean id="user2"> <property name="id" value="1"/> <property name="userName" value="P"/> <property name="passWord" value="233"/> </bean> <bean id="ioC_By_P" p:id="1" p:name="命名空间" p:user-ref="user2"></bean>
测试代码
public class IoC_Test {private ApplicationContext ctx;@Before public void load() {//读取applicationContext.xml配置文件ctx = new ClassPathXmlApplicationContext("applicationContext.xml");}@Test public void PTest() {IoC_By_P ioc = (IoC_By_P) ctx.getBean("ioC_By_P");ioc.checkAttr();}}控制台结果
id:1----------------------------name:命名空间----------------------------user:1|P|233----------------------------全部正确！！！
5、使用注解方式注入
Spring在3.0以后，提供了基于Annotation（注解）的注入。
1.@Autowired-对成员变量、方法和构造函数进行标注，来完成自动装配的工作，不推荐使用
2.@Qualifier-配合@Autowired来解决装配多个同类型的bean
3.@Resource-JSR-250标准注解，作用相当于@Autowired，只不过@Autowired按byType自动注入，而@Resource默认按byName自动注入
4.@PostConstruct-在方法上加上注解@PostConstruct，这个方法就会在Bean初始化之后被Spring容器执行
5.@PreDestroy-在方法上加上注解@PreDestroy，这个方法就会在Bean初始化之后被Spring容器执行
6.@Component-只需要在对应的类上加上一个@Component注解，就将该类定义为一个Bean，不推荐使用，推荐使用更加细化的三种：@Repository、@Service、@Controller
@Repository存储层Bean
@Service业务层Bean
@Controller展示层Bean
7.@Scope-定义Bean的作用范围
首先配置applicationContext.xml开启注解
<!-- 扫描包中注解标注的类 --> <context:component-scan base-package="com.bc.ioc.demo05"/>
实体Bean加注解
@Repositorypublic class User {private Integer id = 1;private String userName = "注解注入";private String passWord = "233";public User() {super();}public User(Integer id, String userName, String passWord) {super();this.id = id;this.userName = userName;this.passWord = passWord;}public Integer getId() {return id;}public String getUserName() {return userName;}public String getPassWord() {return passWord;}public void setId(Integer id) {this.id = id;}public void setUserName(String userName) {this.userName = userName;}public void setPassWord(String passWord) {this.passWord = passWord;}}测试类代码加注解
/**使用注解注入属性*/@Service("ioC_By_Annotation")public class IoC_By_Annotation {@Resource private User user;public void setUser(User user) {this.user = user;}/**检查是否注入成功*/public Boolean checkAttr() {if(user == null) {return false;} else {System.out.println("user:" + user.getId() + "|" + user.getUserName() + "|" + user.getPassWord());}System.out.println("正确！！！");return true;}}测试代码
public class IoC_Test {private ApplicationContext ctx;@Before public void load() {//读取applicationContext.xml配置文件ctx = new ClassPathXmlApplicationContext("applicationContext.xml");}@Test public void annotationTest() {IoC_By_Annotation ioc = (IoC_By_Annotation) ctx.getBean("ioC_By_Annotation");ioc.checkAttr();}}控制台输出
经测试使用注解注入如果applicationContext.xml配置有其他注入方式会报错,也会导致其他注入方式异常。
user:1|注解注入|233正确！！！
6、通过配置静态工厂方法Bean注入
静态工厂代码
/**静态工厂*/public class StaticFactory {public static Integer getId() {return 1;}public static String getName() {return "静态工厂";}public static User getUser() {return new User(1, "工厂User", "666");}}测试类代码
/** 通过静态工厂方式注入 */public class IoC_By_StaticFactory {private Integer id;private String name;private User user;/** 检查是否注入成功 */public Boolean checkAttr() {if (id == null) {return false;} else {System.out.println("id:" + id);}System.out.println("----------------------------");if (name == null) {return false;} else {System.out.println("name:" + name);}System.out.println("----------------------------");if (user == null) {return false;} else {System.out.println("user:" + user.getId() + "|" + user.getUserName() + "|" + user.getPassWord());}System.out.println("----------------------------");System.out.println("全部正确！！！");return true;}/**需要为需要注入的属性设置set方法*/public void setId(Integer id) {this.id = id;}public void setName(String name) {this.name = name;}public void setUser(User user) {this.user = user;}}applicationContext.xml配置
<!-- 配置静态工厂方法Bean 其实就是将工厂方法返回的数值配置成Bean --> <bean id="factory_id" factory-method="getId"/> <bean id="factory_name" factory-method="getName"/> <bean id="factory_user" factory-method="getUser"/> <!-- 注入对应的静态工厂方法Bean --> <bean id="ioC_By_StaticFactory"> <property name="id" ref="factory_id"/> <property name="name" ref="factory_name"/> <property name="user" ref="factory_user"/> </bean>
测试代码
public class IoC_Test {private ApplicationContext ctx;@Before public void load() {//读取applicationContext.xml配置文件ctx = new ClassPathXmlApplicationContext("applicationContext.xml");}@Test public void staticFactoryTest() {IoC_By_StaticFactory ioc = (IoC_By_StaticFactory) ctx.getBean("ioC_By_StaticFactory");ioc.checkAttr();}}控制台输出结果
id:1----------------------------name:静态工厂----------------------------user:1|工厂User|666----------------------------全部正确！！！
7、通过实例工厂方法注入
与静态工厂区别在于实例工厂不是静态的,需要先new 一个实例工厂对象,才可以配置其方法,而new 的这个对象也由spring来管理
工厂代码
/**实例工厂*/public class Factory {public Integer getId() {return 1;}public String getName() {return "实例工厂";}public User getUser() {return new User(1, "实例工厂User", "233");}}测试类代码
/**实例工厂注入*/public class IoC_By_Factory {private Integer id;private String name;private User user;/** 检查是否注入成功 */public Boolean checkAttr() {if (id == null) {return false;} else {System.out.println("id:" + id);}System.out.println("----------------------------");if (name == null) {return false;} else {System.out.println("name:" + name);}System.out.println("----------------------------");if (user == null) {return false;} else {System.out.println("user:" + user.getId() + "|" + user.getUserName() + "|" + user.getPassWord());}System.out.println("----------------------------");System.out.println("全部正确！！！");return true;}/**需要为需要注入的属性设置set方法*/public void setId(Integer id) {this.id = id;}public void setName(String name) {this.name = name;}public void setUser(User user) {this.user = user;}}applicationContext.xml配置
<!-- 配置实例工厂Bean --> <bean id="factory"/> <!-- 配置实例工厂方法Bean --> <bean id="f_id" factory-bean="factory" factory-method="getId"/> <bean id="f_name" factory-bean="factory" factory-method="getName"/> <bean id="f_user" factory-bean="factory" factory-method="getUser"/> <!-- 注入对应的实例工厂方法Bean --> <bean id="ioC_By_Factory"> <property name="id" ref="f_id"/> <property name="name" ref="f_name"/> <property name="user" ref="f_user"/> </bean>
测试类代码
public class IoC_Test {private ApplicationContext ctx;@Before public void load() {//读取applicationContext.xml配置文件ctx = new ClassPathXmlApplicationContext("applicationContext.xml");}@Test public void factoryTest() {IoC_By_Factory ioc = (IoC_By_Factory) ctx.getBean("ioC_By_Factory");ioc.checkAttr();}}控制台输出
id:1----------------------------name:实例工厂----------------------------user:1|实例工厂User|233----------------------------全部正确！！！
总结
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