利用反射机制模拟SPRING IOC实现

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>


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;
	}

}

猜你喜欢

转载自json20080301.iteye.com/blog/1319320