♻️ 重构红包代码

crossoverJie · crossoverJie · commit 2e380052b82c · 2018-10-31T22:36:07.000+08:00
🔒 安全修复
diff --git a/pom.xml b/pom.xml
@@ -91,7 +91,7 @@
         <dependency>
             <groupId>com.alibaba</groupId>
             <artifactId>fastjson</artifactId>
-            <version>1.1.40</version>
+            <version>1.2.31</version>
         </dependency>
 
         <dependency>
diff --git a/src/main/java/com/crossoverjie/red/RedPacket.java b/src/main/java/com/crossoverjie/red/RedPacket.java
@@ -15,121 +15,129 @@ public class RedPacket {
     /**
      * 生成红包最小值 1分
      */
-    private static final int MIN_MONEY = 1 ;
+    private static final int MIN_MONEY = 1;
 
     /**
      * 生成红包最大值 200人民币
      */
-    private static final int MAX_MONEY = 200 * 100 ;
+    private static final int MAX_MONEY = 200 * 100;
 
     /**
      * 小于最小值
      */
-    private static final int LESS = -1 ;
+    private static final int LESS = -1;
     /**
      * 大于最大值
      */
-    private static final int MORE = -2 ;
+    private static final int MORE = -2;
 
     /**
      * 正常值
      */
-    private static final int OK = 1 ;
+    private static final int OK = 1;
 
     /**
      * 最大的红包是平均值的 TIMES 倍，防止某一次分配红包较大
      */
-    private static final double TIMES = 2.1F ;
+    private static final double TIMES = 2.1F;
 
-    private int recursiveCount = 0 ;
+    private int recursiveCount = 0;
+
+    public List<Integer> splitRedPacket(int money, int count) {
+        List<Integer> moneys = new LinkedList<>();
+
+        //金额检查，如果最大红包 * 个数 < 总金额；则需要调大最小红包 MAX_MONEY
+        if (MAX_MONEY * count <= money) {
+            System.err.println("请调大最小红包金额 MAX_MONEY=[" + MAX_MONEY + "]");
+            return moneys ;
+        }
 
-    private List<Integer> splitRedPacket(int money,int count){
-        List<Integer> moneys = new LinkedList<>() ;
 
         //计算出最大红包
-        int max = (int) ((money / count) * TIMES) ;
-        max = max > MAX_MONEY ? MAX_MONEY : max ;
+        int max = (int) ((money / count) * TIMES);
+        max = max > MAX_MONEY ? MAX_MONEY : max;
 
-        for (int i = 0 ; i< count ; i++){
+        for (int i = 0; i < count; i++) {
             //随机获取红包
-            int redPacket = randomRedPacket(money, MIN_MONEY,max,count - i) ;
+            int redPacket = randomRedPacket(money, MIN_MONEY, max, count - i);
             moneys.add(redPacket);
             //总金额每次减少
-            money -= redPacket ;
+            money -= redPacket;
         }
 
-        return moneys ;
+        return moneys;
     }
 
     private int randomRedPacket(int totalMoney, int minMoney, int maxMoney, int count) {
         //只有一个红包直接返回
-        if (count == 1){
-            return totalMoney ;
+        if (count == 1) {
+            return totalMoney;
         }
 
-        if (minMoney == maxMoney){
-            return minMoney ;
+        if (minMoney == maxMoney) {
+            return minMoney;
         }
 
         //如果最大金额大于了剩余金额 则用剩余金额 因为这个 money 每分配一次都会减小
-        maxMoney = maxMoney > totalMoney ? totalMoney : maxMoney ;
+        maxMoney = maxMoney > totalMoney ? totalMoney : maxMoney;
 
         //在 minMoney到maxMoney 生成一个随机红包
-        int redPacket = (int) (Math.random() * (maxMoney - minMoney) + minMoney) ;
+        int redPacket = (int) (Math.random() * (maxMoney - minMoney) + minMoney);
 
-        int lastMoney = totalMoney - redPacket ;
+        int lastMoney = totalMoney - redPacket;
 
-        int status = checkMoney(lastMoney,count - 1) ;
+        int status = checkMoney(lastMoney, count - 1);
 
         //正常金额
-        if (OK == status){
-            return redPacket ;
+        if (OK == status) {
+            return redPacket;
         }
 
         //如果生成的金额不合法 则递归重新生成
-        if (LESS == status){
-            recursiveCount ++ ;
+        if (LESS == status) {
+            recursiveCount++;
             System.out.println("recursiveCount==" + recursiveCount);
-            return randomRedPacket(totalMoney,minMoney,redPacket,count) ;
+            return randomRedPacket(totalMoney, minMoney, redPacket, count);
         }
 
-        if (MORE == status){
-            recursiveCount ++ ;
+        if (MORE == status) {
+            recursiveCount++;
             System.out.println("recursiveCount===" + recursiveCount);
-            return randomRedPacket(totalMoney,redPacket,maxMoney,count) ;
+            return randomRedPacket(totalMoney, redPacket, maxMoney, count);
         }
 
-        return redPacket ;
+        return redPacket;
     }
 
     /**
      * 校验剩余的金额的平均值是否在 最小值和最大值这个范围内
+     *
      * @param lastMoney
      * @param count
      * @return
      */
     private int checkMoney(int lastMoney, int count) {
-        double avg = lastMoney / count ;
-        if (avg < MIN_MONEY){
-            return LESS ;
+        double avg = lastMoney / count;
+        if (avg < MIN_MONEY) {
+            return LESS;
         }
 
-        if (avg > MAX_MONEY){
-            return MORE ;
+        if (avg > MAX_MONEY) {
+            return MORE;
         }
 
-        return OK ;
+        return OK;
     }
 
 
     public static void main(String[] args) {
-        RedPacket redPacket = new RedPacket() ;
+        RedPacket redPacket = new RedPacket();
         List<Integer> redPackets = redPacket.splitRedPacket(20000, 100);
-        System.out.println(redPackets) ;
+        System.out.println(redPackets);
 
-        int sum = 0 ;
+        int sum = 0;
         for (Integer red : redPackets) {
-            sum += red ;
+            sum += red;
         }
         System.out.println(sum);
     }
diff --git a/src/test/java/com/crossoverjie/red/RedPacketTest.java b/src/test/java/com/crossoverjie/red/RedPacketTest.java
@@ -0,0 +1,34 @@
+package com.crossoverjie.red;
+
+import org.junit.Test;
+
+import java.util.List;
+
+public class RedPacketTest {
+
+    @Test
+    public void right(){
+        RedPacket redPacket = new RedPacket() ;
+        List<Integer> redPackets = redPacket.splitRedPacket(20000, 100);
+        System.out.println(redPackets) ;
+
+        int sum = 0 ;
+        for (Integer red : redPackets) {
+            sum += red ;
+        }
+        System.out.println(sum);
+    }
+
+    @Test
+    public void right_(){
+        RedPacket redPacket = new RedPacket() ;
+        List<Integer> redPackets = redPacket.splitRedPacket(40000, 2);
+        System.out.println(redPackets) ;
+
+        int sum = 0 ;
+        for (Integer red : redPackets) {
+            sum += red ;
+        }
+        System.out.println(sum);
+    }
+}
