JAVA重构规则

「爱情、让人受尽委屈。」 2022-02-01 06:15 144阅读 0赞

##### No.1：重复代码的提炼 #####

class BadExample {
    
        public void someMethod1(){
            //code
            System.out.println("重复代码");/* 重复代码块 */
            //code
        }
        
        public void someMethod2(){
            //code
            System.out.println("重复代码");/* 重复代码块 */
            //code
        }
        
    }
    
    /* ---------------------分割线---------------------- */
    
    class GoodExample {
    
        public void someMethod1(){
            //code
            someMethod3();
            //code
        }
        
        public void someMethod2(){
            //code
            someMethod3();
            //code
        }
        
        public void someMethod3(){
            System.out.println("重复代码");/* 重复代码块 */
        }
        
    }

##### No.2：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]
        }
        
    }

##### No.3：嵌套条件分支的优化（1） #####

class BadExample {
    
        public void someMethod(Object A,Object B){
            if (A != null) {
                if (B != null) {
                    //code[1]
                }else {
                    //code[3]
                }
            }else {
                //code[2]
            }
        }
        
    }
    
    /* ---------------------分割线---------------------- */
    
    class GoodExample {
    
        public void someMethod(Object A,Object B){
            if (A == null) {
                //code[2]
                return;
            }
            if (B == null) {
                //code[3]
                return;
            }
            //code[1]
        }
        
    }

##### No.4：嵌套条件分支的优化（2） #####

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
            }
        }
        
    }

##### No.5：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;
        }
        
    }

##### No.6：消除过长参数列表 #####

class BadExample {
        
        public void someMethod(int i,int j,int k,int l,int m,int n){
            //code
        }
        
    }
    
    /* ---------------------分割线---------------------- */
    
    class GoodExample {
    
        public void someMethod(Data data){
            //code
        }
        
    }
    
    class Data{
        
        private int i;
        private int j;
        private int k;
        private int l;
        private int m;
        private int n;
    
    　　//getter&&setter
        
    }

##### No.7：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
        }
        
    }

##### No.8：让类提供应该提供的方法 #####

class BadExample {
        
        public int someMethod(Data data){
            int i = data.getI();
            int j = data.getJ();
            int k = data.getK();
            return i * j * k;
        }
        
        public static class Data{
            
            private int i;
            private int j;
            private int k;
            
            public Data(int i, int j, int k) {
                super();
                this.i = i;
                this.j = j;
                this.k = k;
            }
    
            public int getI() {
                return i;
            }
            
            public int getJ() {
                return j;
            }
            
            public int getK() {
                return k;
            }
            
        }
        
    }
    
    /* ---------------------分割线---------------------- */
    
    class GoodExample {
        
        public int someMethod(Data data){
            return data.getResult();
        }
        
        public static class Data{
            
            private int i;
            private int j;
            private int k;
            
            public Data(int i, int j, int k) {
                super();
                this.i = i;
                this.j = j;
                this.k = k;
            }
    
            public int getI() {
                return i;
            }
            
            public int getJ() {
                return j;
            }
            
            public int getK() {
                return k;
            }
            
            public int getResult(){
                return i * j * k;
            }
            
        }
        
    }

##### No.9：拆分冗长的类 #####

##### No.10：提取继承体系中重复的属性与方法到父类 #####

[转载][Link 1]：[http://www.cnblogs.com/zuoxiaolong/p/pattern27.html][Link 1]

[Link 1]: http://www.cnblogs.com/zuoxiaolong/p/pattern27.html