java反射---我之见解

最近在做一个项目，开始就没打算使用反射，但是做着做着，发现有很多代码相同！感觉很郁闷，还有很多地方需要运行时才定义的类型，这让我不禁想起了反射，开始只是用一点，然后发现使用反射代码少了，循环多了！很多地方不用写死一个类型，可以使用反射去获取源对象，越做就感觉越好用，甚至连对象封装我都放弃了apache的BeanUtils，自己去写一个封装的方法，可能性能和优势都不够别人强，但是爆出异常至少我可以控制到！这个是使用框架无法做到的！
所以我觉得，作为一个优秀的程序员，需要懂得反射，会用反射，如果作为一个架构师，需要精通反射！有了反射可以让代码更少，让代码的复用性更高更容易维护！而且会减少模块和模块之间的耦合，进一步做到了低耦合高内聚！

 

public class DemoBean {
	private String name;
	private String engName;
	private int age;
	private String dept;
	private String address;
	private String phone;
	private String info;
	private String desc;

	public String getName() {
		return name;
	}

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

	public String getEngName() {
		return engName;
	}

	public void setEngName(String engName) {
		this.engName = engName;
	}

	public int getAge() {
		return age;
	}

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

	public String getDept() {
		return dept;
	}

	public void setDept(String dept) {
		this.dept = dept;
	}

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

	public String getPhone() {
		return phone;
	}

	public void setPhone(String phone) {
		this.phone = phone;
	}

	public String getInfo() {
		return info;
	}

	public void setInfo(String info) {
		this.info = info;
	}

	public String getDesc() {
		return desc;
	}

	public void setDesc(String desc) {
		this.desc = desc;
	}

}

 

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

public class Demo {
	public static void main(String[] args) throws SecurityException,
			NoSuchFieldException, NoSuchMethodException,
			IllegalArgumentException, IllegalAccessException,
			InvocationTargetException {
		DemoBean2 db = new DemoBean2();
		merge(db, getMap());
		System.out.println(db.getAge());
		System.out.println(db.getEngName());
		System.out.println(db.getDept());
		System.out.println(db.getInfo());
		System.out.println(db.getAddress());
		System.out.println(db.getPhone());
	}

	public static void merge(Object bean, Map<String, Object> map)
			throws SecurityException, NoSuchFieldException,
			NoSuchMethodException, IllegalArgumentException,
			IllegalAccessException, InvocationTargetException {
		Set<String> set = map.keySet();
		Iterator<String> it = set.iterator();
		while (it.hasNext()) {
			String fieldName = it.next();
			Field f = bean.getClass().getDeclaredField(fieldName);
			String methodName = fieldName.substring(0, 1).toUpperCase()
					+ fieldName.substring(1, fieldName.length());
			Method m = bean.getClass().getDeclaredMethod("set" + methodName,
					f.getType());
			m.invoke(bean, map.get(fieldName));
		}
	}

	public static Map<String, Object> getMap() {
		Map<String, Object> map = new HashMap<String, Object>();
		map.put("engName", "vincent");
		map.put("age", 12);
		map.put("dept", "Boss");
		map.put("address", "中国北京");
		map.put("phone", "12450358357");
		map.put("info", "this is infomation");
		return map;
	}
}

 

    利用反射去封装一个实体,这样无论你在map里面放入多少个元素都和可以完整的封装到实体里面，用别的方法就比较难实现了！

评论

2 楼 hnzuoxian 2009-01-05  

1 楼 huaiwen 2008-09-29  

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