注入方式一：set注入

<bean id="exampleBean" class="examples.ExampleBean"><!-- setter injection using the nested <ref/> element -->
<property name="beanOne"><ref bean="anotherExampleBean"/></property><!-- setter injection using the neater 'ref' attribute -->
<property name="beanTwo" ref="yetAnotherBean"/>
<property name="integerProperty" value="1"/>
</bean><bean id="anotherExampleBean" class="examples.AnotherBean"/>
<bean id="yetAnotherBean" class="examples.YetAnotherBean"/>

public class ExampleBean {private AnotherBean beanOne;private YetAnotherBean beanTwo;private int i;public void setBeanOne(AnotherBean beanOne) {this.beanOne = beanOne;}public void setBeanTwo(YetAnotherBean beanTwo) {this.beanTwo = beanTwo;}public void setIntegerProperty(int i) {this.i = i;}
}

注入方式二：构造注入

<bean id="exampleBean" class="examples.ExampleBean"><!-- constructor injection using the nested <ref/> element -->
<constructor-arg><ref bean="anotherExampleBean"/>
</constructor-arg><!-- constructor injection using the neater 'ref' attribute -->
<constructor-arg ref="yetAnotherBean"/><constructor-arg type="int" value="1"/>
</bean><bean id="anotherExampleBean" class="examples.AnotherBean"/>
<bean id="yetAnotherBean" class="examples.YetAnotherBean"/>

public class ExampleBean {private AnotherBean beanOne;private YetAnotherBean beanTwo;private int i;public ExampleBean(AnotherBean anotherBean, YetAnotherBean yetAnotherBean, int i) {this.beanOne = anotherBean;this.beanTwo = yetAnotherBean;this.i = i;}
}

注入方式三：静态工厂方法注入

<bean id="exampleBean" class="examples.ExampleBean"factory-method="createInstance">
<constructor-arg ref="anotherExampleBean"/>
<constructor-arg ref="yetAnotherBean"/>
<constructor-arg value="1"/>
</bean><bean id="anotherExampleBean" class="examples.AnotherBean"/>
<bean id="yetAnotherBean" class="examples.YetAnotherBean"/>

public class ExampleBean {// a private constructorprivate ExampleBean(...) {...}// a static factory method; the arguments to this method can be// considered the dependencies of the bean that is returned,// regardless of how those arguments are actually used.public static ExampleBean createInstance (AnotherBean anotherBean, YetAnotherBean yetAnotherBean, int i) {ExampleBean eb = new ExampleBean (...);// some other operations...return eb;}
}

注入方式四：自动装配