spring中使用autowire特性时注意

spring中可以只用autowire="byName"或者"byType"来提供自动注入。但是大家有一点还需要注意，那就是它不支持基本数据类型(String，int，long等)的自动注入。例如
J***A类：
public class TestBean {
private String name;
private Long age;
private String fullName;
private TestBean2 testBean2;

public void setTestBean2(TestBean2 testBean2) {
this.testBean2 = testBean2;
}
public TestBean2 getTestBean2() {
return testBean2;
}
public void setFullName(String fullName) {
this.fullName = fullName;
}
public String getFullName() {
return fullName;
}

public void setAge(Long age) {
this.age = age;
}

public Long getAge() {
return age;
}

public void setName(String name) {
this.name = name;
}

public String getName() {
return name;
}
}

J***A类2：
public class TestBean2 {
public String getString(){
return "testB";
}
}
配置文件：
<beans default-autowire="byName">
<!-- login -->
<bean id="testBean" class="TestBean">
<property name="fullName">
<value>fullName</value>
</property>
</bean>
<bean id="name" class="java.lang.String">
<constructor-arg>
<value>hell</value>
</constructor-arg>
</bean>
<bean id="age" class="java.lang.Long">
<constructor-arg>
<value>20</value>
</constructor-arg>
</bean>
<bean id="testBean2" class="TestBean2"/>
</beans>
测试类：
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {
public static void main(String[] args) {
ClassPathXmlApplicationContext t = new ClassPathXmlApplicationContext(
"test.xml");
TestBean bean = (TestBean) t.getBean("testBean");
System.out.println("name:" + bean.getName() + " age:" + bean.getAge()
+ " fullName :" + bean.getFullName() + " testBean2"
+ bean.getTestBean2().getString());
}

}
输出的结果是：
name:null age:null fullName :fullName testBean2:testB

spring源码中排除基本类型的代码（源码来自：org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory类）在：
protected String[] unsatisfiedNonSimpleProperties(AbstractBeanDefinition mbd, BeanWrapper bw) {
Set result = new TreeSet();
PropertyValues pvs = mbd.getPropertyValues();
PropertyDescriptor[] pds = bw.getPropertyDescriptors();
for (int i = 0; i < pds.length; i++) {
if (pds[i].getWriteMethod() != null && !isExcludedFromDependencyCheck(pds[i]) &&
!pvs.contains(pds[i].getName()) && !BeanUtils.isSimpleProperty(pds[i].getPropertyType())) {
result.add(pds[i].getName());
}
}
return StringUtils.toStringArray(result);
}


请注意以上紫色部分。而这个unsatisfiedNonSimpleProperties方法都是在自动注入时调用。所以基本类型不会被注入。