一、Spring基礎
1、核心
（1）IoC/Dependency Injection
l IoC/Dependency Injection（依賴注入）：Beans不依賴於框架；容器注入依賴
l 輕量級Spring容器：配置和管理Beans
<beans><bean id="exampleBean" class="eg.ExampleBean"/>
<bean id="anotherExample" class="eg.ExampleBeanTwo"/>
</beans>InputStream input = new FileInputStream("beans.xml");BeanFactory factory = new XmlBeanFactory(input);ExampleBean eb = (ExampleBean)factory.getBean("exampleBean");
ExampleBeanTwo eb2 = (ExampleBeanTwo)factory.getBean("anotherExample");
可能會拋出NoSuchBeanDefinitionException；
ExampleBean eb = (ExampleBean)factory.getBean("exampleBean", ExampleBean.class);
可能會拋出BeanNotOfRequiredTypeException；
package eg;public class ExampleBean {private AnotherBean beanOne;private YetAnotherBean beanTwo;public void setBeanOne(AnotherBean b) { beanOne = b; }public void setBeanTwo(YetAnotherBean b) { beanTwo = b; }}
<bean id="exampleBean" class="eg.ExampleBean"><property name="beanOne"><ref bean="anotherExampleBean"/></property>
<property name="beanTwo"><ref bean="yetAnotherBean"/></property>
</bean><bean id="anotherExampleBean" class="eg.AnotherBean"/>
<bean id="yetAnotherBean" class="eg.YetAnotherBean"/>
package eg;public class ExampleBean {private String s;private int i;public void setStringProperty(String s) { this.s = s; }
public void setIntegerProperty(int i) { this.i = i; }
}<bean id="exampleBean" class="eg.ExampleBean"><property name="stringProperty"><value>Hi!</value></property>
<property name="integerProperty"><value>1</value></property>
</bean><property name="intProperty"><value>7</value></property>
<property name="doubleProperty"><value>0.25</value></property>
<property name="booleanProperty"><value>true</value></property>
<property name="colorProperty"><value>0,255,0</value></property>
<property name="classProperty">
<value>java.lang.Object</value>
</property><property name="fileProperty">
<value>/home/ziba/file.txt</value>
</property><property name="localeProperty">
<value>pt_BR</value>
</property><property name="urlProperty">
<value>http://java.net</value>
</property><property name="stringArrayProperty">
<value>foo,bar,baz</value>
</property>DateFormat fmt = new SimpleDateFormat("d/M/yyyy");CustomDateEditor dateEditor = new CustomDateEditor(fmt, false);
beanFactory.registerCustomEditor(java.util.Date.class, dateEditor);
<property name="date"><value>19/2/2004</value></property>
StringTrimmerEditor trimmer = new StringTrimmerEditor(true);beanFactory.registerCustomEditor(java.lang.String.class, trimmer);
<property name="string1"><value> hello </value></property>
<property name="string2"><value></value></property>
<property name="string2"><null/></property>
<property name="propertiesProperty"><value>foo=1bar=2baz=3</value></property>
<property name="propertiesProperty"><props><prop key="foo">1</prop><prop key="bar">2</prop><prop key="baz">3</prop></props></property><property name="listProperty"><list><value>a list element</value><ref bean="otherBean"/><ref bean="anotherBean"/></list></property><property name="setProperty"><set><value>a set element</value><ref bean="otherBean"/><ref bean="anotherBean"/></set></property><property name="mapProperty"><map><entry key="yup an entry"><value>just some string</value></entry><entry key="yup a ref"><ref bean="otherBean"/></entry></map></property>public class ExampleBean {private AnotherBean beanOne;private YetAnotherBean beanTwo;private int i;public ExampleBean(AnotherBean b1, YetAnotherBean b2, int i) {
this.beanOne = b1;this.beanTwo = b2;this.i = i;}}
<bean id="exampleBean" class="eg.ExampleBean"><constructor-arg><ref bean="anotherExampleBean"/></constructor-arg>
<constructor-arg><ref bean="yetAnotherBean"/></constructor-arg>
<constructor-arg><value>1</value></constructor-arg>
</bean><bean id="anotherExampleBean" class="eg.AnotherBean"/><bean id="yetAnotherBean" class="eg.YetAnotherBean"/>public class ExampleBean {public void init() {
// do some initialization work}}
<bean id="exampleBean" class="eg.ExampleBean" init-method="init"/>
public class ExampleBean {public void cleanup() {
// do some destruction work}}
<bean id="exampleBean" class="eg.ExampleBean" destroy-method="cleanup"/>
（16）PropertyPlaceholderConfigurer
l 從外部Properties文件中併入屬性
<bean id="dataSource"class="org.apache.commons.dbcp.BasicDataSource"destroy-method="close"><property name="driverClassName"><value>${jdbc.driverClassName}</value>
</property><property name="url"><value>${jdbc.url}</value></property>
<property name="username"><value>${jdbc.username}</value></property>
<property name="password"><value>${jdbc.password}</value></property>
</bean>jdbc.properties
jdbc.driverClassName=org.hsqldb.jdbcDriver
jdbc.url=jdbc:hsqldb:hsql://production:9002
jdbc.username=sa
jdbc.password=root
l 安裝Configurer
InputStream input = new FileInputStream("beans.xml");XmlBeanFactory factory = new XmlBeanFactory(input);Properties props = new Properties();props.load(new FileInputStream("jdbc.properties"));PropertyPlaceholderConfigurer cfg = new PropertyPlaceholderConfigurer();
cfg.setProperties(props);cfg.postProcessBeanFactory(factory);DataSource ds = (DataSource)factory.getBean("dataSource");（17）MethodInvokingFactoryBean
l 暴露使用Singleton模式的Bean
package eg;public class MySingleton {private static MySingleton instance = new MySingleton();private MySingleton() {}public static MySingleton getInstance() {return instance;}} <bean name="mySingleton"class="...beans.factory.config.MethodInvokingFactoryBean"><property name="staticMethod"><value>eg.MySingleton.getInstance</value></property></bean>MySingleton singleton = (MySingleton)ctx.getBean("mySingleton");
FactoryBean factory = (FactoryBean)ctx.getBean("&mySingleton");
