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添加代码优化技巧总结

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	`1`	`+package com.learnjava.optimization;`
	`2`	`+`
	`3`	`+import java.util.HashMap;`
	`4`	`+import java.util.Map;`
	`5`	`+`
	`6`	`+/**`
	`7`	`+ *`
	`8`	`+ * 代码优化技巧总结`
	`9`	`+ *`
	`10`	`+ * @author lhy`
	`11`	`+ * @date 2021年7月19日`
	`12`	`+ */`
	`13`	`+public class OptimizeDemo {`
	`14`	`+ public static void main(String[] args) {`
	`15`	`+ Map<String, Integer> map = new HashMap<>();`
	`16`	`+ mergeData(map);`
	`17`	`+ }`
	`18`	`+`
	`19`	`+ /**`
	`20`	`+ * 对于通过map来聚合数据(非Lambda方式)`
	`21`	`+ * @param map`
	`22`	`+ */`
	`23`	`+ public static void mergeData(Map<String, Integer> map) {`
	`24`	`+ String key = "mapKey";`
	`25`	`+ int value = 1;`
	`26`	`+ // 普通方式`
	`27`	`+ if (map.containsKey(key)) {`
	`28`	`+ map.put(key, map.get(key) + value);`
	`29`	`+ } else {`
	`30`	`+ map.put(key,value);`
	`31`	`+ }`
	`32`	`+`
	`33`	`+ // 简洁方式`
	`34`	`+ Integer mapValue = map.get(key);`
	`35`	`+ if (null != mapValue) {`
	`36`	`+ mapValue += value;`
	`37`	`+ }`
	`38`	`+ map.put(key, mapValue);`
	`39`	`+ }`
	`40`	`+}`

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