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‎JdkLearn/src/main/java/com/learnjava/optimization/OptimizeDemo.java‎
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‎JdkLearn/src/main/java/com/learnjava/optimization/OptimizeDemo.java‎
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+40Lines changed: 40 additions & 0 deletions
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+package com.learnjava.optimization;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ *
+ * 代码优化技巧总结
+ *
+ * @author lhy
+ * @date 2021/7/19
+ */
+public class OptimizeDemo {
+    public static void main(String[] args) {
+        Map<String, Integer> map = new HashMap<>();
+        mergeData(map);
+    }
+
+    /**
+     * 对于通过map来聚合数据（非Lambda方式）
+     * @param map
+     */
+    public static void mergeData(Map<String, Integer> map) {
+        String key = "mapKey";
+        int value = 1;
+        // 普通方式
+        if (map.containsKey(key)) {
+            map.put(key, map.get(key) + value);
+        } else {
+            map.put(key,value);
+        }
+
+        // 简洁方式
+        Integer mapValue = map.get(key);
+        if (null != mapValue) {
+            mapValue += value;
+        }
+        map.put(key, mapValue);
+    }
+}