Bean 的四种构造方式

1.通过构造函数创建

    <bean id='injectBean' class="di.InjectBean"></bean>
    <bean id="diConstruct" class="di.DependencyInjectConstruct">
    	<constructor-arg type="java.lang.String" value="Inject construct test"/>
        <constructor-arg ref="injectBean"/>
    </bean>

 

package di;

public class DependencyInjectConstruct {
	private final String value;
	private final InjectBean injectBean;
	public DependencyInjectConstruct(String value, InjectBean injectBean) {
		this.value = value;
		this.injectBean = injectBean;
	}
	
	public void print() {
		System.out.println(value);
		System.out.println(injectBean);
	}
}

 2.通过Setter注入

	<bean id="diSetter" class="di.DependencyInjectSetter">
		<property name="value" value="Inject setter test"/>
		<property name="injectBean" ref="injectBean"/>
	</bean>

 

package di;

public class DependencyInjectSetter {
	private String value;
	private InjectBean injectBean;
	public void setValue(String value) {
		this.value = value;
	}
	public void setInjectBean(InjectBean injectBean) {
		this.injectBean = injectBean;
	}
	@Override
	public String toString() {
		return "DependencyInjectSetter [value=" + value + ", injectBean=" + injectBean + "]";
	}
}

 3.通过工厂方法

<bean id="diStaticMethod" class="di.DependencyInjectStaticMethod" factory-method="create"></bean>

 

package di;

public class DependencyInjectStaticMethod {
	private final String value;
	private final InjectBean injectBean;
	
	private DependencyInjectStaticMethod(String value, InjectBean injectBean) {
		this.value = value;
		this.injectBean = injectBean;
	}
	
	public static DependencyInjectStaticMethod create() {
		return new DependencyInjectStaticMethod("Dependency inject for status method", new InjectBean());
	}

	@Override
	public String toString() {
		return "DependencyInjectStaticMethod [value=" + value + ", injectBean=" + injectBean + "]";
	}
	
	
}

 4.如果需要的非static的工厂方法可以用factory-bean类引用一个对象来创建bean

<bean id="factoryBean" class="di.DependencyInjectMethod"></bean>
	<bean id="diMethod" class="di.DependencyInjectStaticMethod" factory-bean="factoryBean" factory-method="create"></bean>

 

package di;

public class DependencyInjectMethod {
	private String value;
	private InjectBean injectBean;
	
	public DependencyInjectMethod() {
	}
	
	private DependencyInjectMethod(String value, InjectBean injectBean) {
		this.value = value;
		this.injectBean = injectBean;
	}
	
	public DependencyInjectMethod create() {
		return new DependencyInjectMethod("Dependency inject for method", new InjectBean());
	}

	@Override
	public String toString() {
		return "DependencyInjectMethod [value=" + value + ", injectBean=" + injectBean + "]";
	}
	
	
}