com.hecloud.runtime.common.collections.Maps Maven / Gradle / Ivy

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package com.hecloud.runtime.common.collections;

import com.alibaba.fastjson.JSONObject;

import java.util.*;

/**
 * @author LoveinBJ
 */
public class Maps {

    public static boolean isEmpty(Map map) {
        return null == map || map.size() == 0;
    }

    /**
     * 创建简单的Map 

     * 返回示例：{key : value}
     *
     * @param key   键
     * @param value 值
     * @return map对象
     */
    public static Map single(String key, Object value) {
        Map map = new HashMap<>(16, 0.75F);
        map.put(key, value);
        return map;
    }

    public static String string(Map map) {
        final Map target = Optional.ofNullable(map).orElse(new HashMap<>(0));
        clear(target);
        StringBuilder builder = new StringBuilder();
        List keyList = new ArrayList<>(map.keySet());
        Collections.sort(keyList);
        keyList.stream().filter(key -> Objects.nonNull(target.get(key)))
                .forEach(key -> builder.append(key).append("=")
                        .append(JSONObject.toJSONString(map.get(key)).replace("\"", ""))
                        .append("&"));
        builder.deleteCharAt(builder.length() - 1);
        return builder.toString();
    }

    /**
     * 移除key值为空或者value值为空的的数据 

     * 例如：sourceMap = {null:"c","b":"b"}，处理之后为：sourceMap = {"b":"b"}
     *
     * @param source 待清理空值map
     */
    private static void clear(Map source) {
        source = Optional.ofNullable(source).orElse(new HashMap<>(0));
        Iterator> iterator = source.entrySet().iterator();
        while (iterator.hasNext()) {
            Map.Entry entry = iterator.next();
            String key = entry.getKey();
            Object value = entry.getValue();
            if (null == key || null == value) {
                iterator.remove();
            }
        }
    }
}