非常使用的重构小技巧，你都知道吗？

一、提取类或继承体系中的常量

    class BadExample { 
    public void someMethod1(){
        send("您的操作已成功！");
    }    
    public void someMethod2(){
        send("您的操作已成功！");
    }    
    public void someMethod3(){
        send("您的操作已成功！");
    }    
    private void send(String message){
        //code
    }
}
/* ---------------------分割线---------------------- */
class GoodExample {    
    protected static final String SUCCESS_MESSAGE = "您的操作已成功！";
    public void someMethod1(){
        send(SUCCESS_MESSAGE);
    }    
    public void someMethod2(){
        send(SUCCESS_MESSAGE);
    }   
    public void someMethod3(){
        send(SUCCESS_MESSAGE);
    }    
    private void send(String message){
        //code
    }    
}

二、去掉一次性的临时变量

class BadExample {    
    private int i;
    public int someMethod(){
        int temp = getVariable();
        return temp * 100;
    }    
    public int getVariable(){
        return i;
    }    
}
/* ---------------------分割线---------------------- */
class GoodExample {
    private int i;
    public int someMethod(){
        return getVariable() * 100;
    }  
    public int getVariable(){
        return i;
    }    
}

三、嵌套条件分支的优化

class BadExample {
    public void someMethod(Object A,Object B){
        if (A != null) {
            if (B != null) {
                //code
            }
        }
    }   
}
/* ---------------------分割线---------------------- */
class GoodExample {
    public void someMethod(Object A,Object B){
        if (A != null && B != null) {
            //code
        }
    }    
}

四、冗长方法的分割

class BadExample {
    public void someMethod(){
        //function[1]
        //function[2]
        //function[3]
    }    
}
/* ---------------------分割线---------------------- */
class GoodExample {
    public void someMethod(){
        function1();
        function2();
        function3();
    }   
    private void function1(){
        //function[1]
    }   
    private void function2(){
        //function[2]
    }
    private void function3(){
        //function[3]
    }  
}