org.apache.commons.collections.MapUtils Map集合工具类

深藏阁楼爱情的钟 2024-02-05 19:27 43阅读 0赞

<dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-collections4</artifactId>
        <version>4.2</version>
    </dependency>

包：org.[apache][].commons.collections4

public static void main(String[] args) {
        
        // 批量赋值
        Map<String, Object> colorMap = MapUtils.putAll(new HashMap<>(),
                new Object[] {
         "str", "我是字符串", "boo", true, "num", 1000 });
        System.out.println("colorMap：" + colorMap.toString()); // colorMap：{str=我是字符串, boo=true, num=1000}
        System.out.println("colorMap-isEmpty：" + MapUtils.isEmpty(colorMap)); // colorMap-isEmpty：false
        System.out.println("colorMap-isNotEmpty：" + MapUtils.isNotEmpty(colorMap)); // colorMap-isNotEmpty：true
     
        // 获取值，还有其他类型可以看MapUtils的API方法
        String str = MapUtils.getString(colorMap, "str");
        System.out.println("str：" + str); // str：我是字符串
     
        Boolean boo = MapUtils.getBoolean(colorMap, "boo");
        System.out.println("boo：" + boo); // boo：true
     
        Integer num = MapUtils.getInteger(colorMap, "num");
        System.out.println("num：" + num); // num：1000
     
        String not = MapUtils.getString(colorMap, "not");
        System.out.println("not：" + not); // not：null
     
        not = MapUtils.getString(colorMap, "not", "未知");
        System.out.println("not：" + not); // not：未知
     
        // 为NULL的情况设置值
        colorMap = MapUtils.emptyIfNull(null);
        System.out.println("colorMap：" + colorMap.toString()); // colorMap：{}
        System.out.println("colorMap-isEmpty：" + MapUtils.isEmpty(colorMap)); // colorMap-isEmpty：true
        System.out.println("colorMap-isNotEmpty：" + MapUtils.isNotEmpty(colorMap)); // colorMap-isNotEmpty：false
     
        // 判断值
        colorMap = null;
        System.out.println("colorMap-isEmpty：" + MapUtils.isEmpty(colorMap)); // colorMap-isEmpty：true
        System.out.println("colorMap-isNotEmpty：" + MapUtils.isNotEmpty(colorMap)); // colorMap-isNotEmpty：false
    }

[apache]: https://so.csdn.net/so/search?q=apache&spm=1001.2101.3001.7020