一個類的簡單SPRING

你是否常編一些小工具,做一些小東西?

在你擴展維護的時候,是不是覺得實例傳遞越來越復雜?

你經常改變想法,但小東西不停重構開始耽誤你越來越多的時間?

你想到了用spring,但又不想對於一個簡單的小東西,引入一個相對小重的框架,讓你的小程序加載時都需要卡一下?

哈,試一試用下simpleFactory,是否可以解決你的煩惱,只有一個類哦,copy一下,就可以幫助你實現依賴注入;

simpleFactory是我在做小實驗時,為了解決上面的問題,自己寫的編碼小工具,至少自己用起來很哈皮

SF代碼:

package com.honeysuckle.webx.context;     
    
import Java.lang.reflect.Constructor;     
import Java.lang.reflect.Method;     
import Java.util.HashMap;     
import Java.util.LinkedList;     
import Java.util.Map;     
import Java.util.Queue;     
    
/**    
 * 類SF.Java的實現描述：SimpleBeanFactory no one simpler than this one    
 *     
 * @author yanghang 2010-9-16 下午04:43:05    
 */    
public class SF {     
    
    private final Map<Class<?>, Object> context = new HashMap<Class<?>, Object>();     
    
    /**    
     * 向容器中放入某個實例    
     * @param clazz 該實例的類型,可以是接口    
     * @param object 該實例    
     */    
    public void put(Class<?> clazz, Object object) {     
        this.context.put(clazz, object);     
    }     
    
    /**    
     * 獲取某個實例(單例) <br/>    
     * 如果容器中不存在,會嘗試初使化: <br/>    
     * 1.調用構造函數,args為可能的構造函數的參數 <br/>    
     * 2.會對該實例的set方法進行注入 <br/>    
     * 3.最後會調用init()方法 <br/>         
     */    
    public Object get(Class<?> clazz, Object... args) {     
        Object object = this.context.get(clazz);     
        if (object == null) {     
            try {     
                object = this.instanceClazz(clazz, args);     
                this.instanceSetMethod(object);     
                this.instanceInitMethod(object);     
                this.put(clazz, object);     
            } catch (Exception e) {     
                return null;     
            }     
        }     
        return object;     
    }     
    
    //獲取某個實例的多例,每次都會重新產生該實例     
    public Object getMulti(Class<?> clazz, Object... args) {     
        Object object;     
        try {     
            object = this.instanceClazz(clazz, args);     
            this.instanceSetMethod(object);     
            this.instanceInitMethod(object);     
        } catch (Exception e) {     
            return null;     
        }     
        return object;     
    }     
    
    //初使化該類,調用構造方法     
    private Object instanceClazz(Class<?> clazz, Object[] args) throws Exception {     
        Object object = null;     
        Class<?>[] clazzes = new Class[args.length];     
        for (int i = 0; i < args.length; i++) {     
            clazzes[i] = args[i].getClass();     
        }     
        Constructor<?>[] cons = clazz.getConstructors();     
        for (Constructor<?> con : cons) {     
            if (con.getParameterTypes().length != args.length) continue;     
            object = con.newInstance(args);     
        }     
        return object;     
    }     
    
    //根據set方法,進行注入     
    private void instanceSetMethod(Object object) {     
        Method[] methods = object.getClass().getDeclaredMethods();     
        Queue<Method> queue = new LinkedList<Method>();     
        for (Method method : methods) {     
            queue.add(method);     
        }     
        for (int i = queue.size(); queue.size() > 0; i = queue.size()) {     
            Method method = queue.poll();     
            if (method.getName().indexOf("set") != 0) continue;     
            Class<?>[] clazzes = method.getParameterTypes();     
            if (clazzes.length != 1) continue;     
            Class<?> pclazz = clazzes[0];     
            try {     
                Object pObject = this.get(pclazz);     
                method.invoke(object, new Object[] { pObject });     
            } catch (Exception e) {     
                continue;     
            }     
            if (i == queue.size()) break;     
        }     
    }     
    
    // 初使化該類,調用init方法     
    private void instanceInitMethod(Object object) {     
        try {     
            Method method = object.getClass().getMethod("init", new Class<?>[] {});     
            method.invoke(object, new Object[] {});     
        } catch (Exception e) {     
            return;     
        }     
    }     
}   

用法示例
有類Bean1

    
public class Bean1 {     
    
    private String hello;     
    
    public void init() {     
        this.hello = "hello kitty";     
    }     
    
    public void show() {     
        System.out.println(this.hello);     
    }     
}    

執行 TestSF

public class TestSF {     
    
    private Bean1 bean;     
    
    public void setBean(Bean1 bean) {     
        this.bean = bean;     
    }     
    
    public void test() {     
        this.bean.show();     
    }     
    
    public static void main(String[] args) {     
        SF sf = new SF();     
        TestSF test = (TestSF) sf.get(TestSF.class);     
        test.test();     
    }     
}   

輸出:

hello kitty