利用JAVA反射机制来简单解释一下IOC实现原理,当然SPRING实现的更完善,但使用的原理和技术是类似;
典型的SPRING IOC 配置代码片段,如何自己使用反射实现见JAVA代码;
<bean id="javabean" class="com.sunshine.test.TestReflect">
<property name="field1" value="test" />
<property name="otherField1" value="AAAA" />
</bean>
典型的SPRING IOC 配置代码片段,如何自己使用反射实现见JAVA代码;
<bean id="javabean" class="com.sunshine.test.TestReflect">
<property name="field1" value="test" />
<property name="otherField1" value="AAAA" />
</bean>
package com.sunshine.test;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
public class TestReflect {
private String field1;
private String field2;
@Override
public String toString() {
return "TestReflect [field1=" + field1 + ", field2=" + field2 + "]";
}
/**
* @param args
* @throws Exception
*
* <bean id="javabean" class="com.sunshine.test.TestReflect">
* <property name="field1" value="test" />
* <property name="otherField1" value="AAAA" />
* </bean>
*/
public static void main(String[] args) throws Exception {
Map<String, Object> context = new HashMap<String, Object>();
String className = TestReflect.class.getName();
String property1 = "field1";
System.out.println("spring 中配置的类名:" + className);
// ----------1.模拟SPRING 利用配置的class 来创建对象实例
Class clazz = Class.forName(className);
Object object = clazz.newInstance();
if (object instanceof TestReflect) {
System.out.println("spring 调用默认构造函数后产生实例:" + object);
}
// ---------2.模拟SPRING 利用配置的property 来进行属性赋值--
Method logMethod = clazz.getDeclaredMethod("set" + "F" + "ield1",
String.class);
logMethod.invoke(object, "test");
System.out.println("spring 实例 的属性赋值后:" + object);
// ---------3.正确理解SPRING属性赋值,其实是调用set方法[set+属性(注意需要大写第一个字母后]来赋值 --
String property2 = "otherField1";
logMethod = clazz.getDeclaredMethod("set" + "O" + "therField1",
String.class);
logMethod.invoke(object, "AAAA");
System.out.println("spring 实例 的属性赋值后:" + object);
// ----------4.模拟SPRING 容器--------------
context.put("javabean", object);
// ---------5 .模拟SPRING 容器取对象-----
Object newObject = context.get("javabean");
System.out.println("spring 取对象:" + newObject);
}
public String getField1() {
return field1;
}
public void setField1(String field1) {
this.field1 = field1;
}
public void setOtherField1(String field) {
this.field2 = field;
}
}