Maps.java

/**
 *  Copyright 2005-2016 Red Hat, Inc.
 *
 *  Red Hat licenses this file to you under the Apache License, version
 *  2.0 (the "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 *  implied.  See the License for the specific language governing
 *  permissions and limitations under the License.
 */
package io.fabric8.utils;

import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

/**
 * Some helper methods for working with maps
 */
public class Maps {

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

    /**
     * Copies the entries for the given keys form the input map to the output map
     */
    public static <K,V> void putAll(Map<K,V> output, Map<K,V> input, K... keys) {
        for (K key : keys) {
            V value = input.get(key);
            if (value != null) {
                output.put(key, value);
            }
        }
    }

    /**
     * Returns the boolean value of the given property in the map or false
     */
    public static boolean booleanValue(Map<String,?> map, String key) {
        return booleanValue(map, key, false);
    }

    /**
     * Returns the boolean value of the given property in the map or returns the default value if its not present
     */
    public static boolean booleanValue(Map<String,?> map, String key, boolean defaultValue) {
        Object obj = map.get(key);
        if (obj == null) {
            return defaultValue;
        } else if (obj instanceof Boolean) {
            Boolean value = (Boolean)obj;
            return value.booleanValue();
        }
        else {
            String text = obj.toString();
            return Boolean.parseBoolean(text);
        }
    }

    /**
     * Returns the Integer value of the given property in the map or null
     */
    public static Integer integerValue(Map<String,?> map, String key) {
        return integerValue(map, key, null);
    }

    /**
     * Returns the Integer value of the given property in the map or returns the default value if its not present
     */
    public static Integer integerValue(Map<String,?> map, String key, Integer defaultValue) {
        Object obj = map.get(key);
        if (obj instanceof Integer) {
            return (Integer) obj;
        } else if (obj instanceof Number) {
            Number number = (Number) obj;
            return number.intValue();
        } else if (obj != null) {
            String text = obj.toString();
            if (Strings.isNotBlank(text)) {
                return Integer.parseInt(text);
            }
        }
        return defaultValue;
    }

    /**
     * Returns the Long value of the given property in the map or null
     */
    public static Long longValue(Map<String,?> map, String key) {
        return longValue(map, key, null);
    }

    /**
     * Returns the Integer value of the given property in the map or returns the default value if its not present
     */
    public static Long longValue(Map<String,?> map, String key, Long defaultValue) {
        Object obj = map.get(key);
        if (obj instanceof Long) {
            return (Long) obj;
        } else if (obj instanceof Number) {
            Number number = (Number) obj;
            return number.longValue();
        } else if (obj != null) {
            String text = obj.toString();
            if (Strings.isNotBlank(text)) {
                return Long.parseLong(text);
            }
        }
        return defaultValue;
    }


    protected static Object valueOrNull(Map<String, Object> map, String key) {
        return value(map, key, null);
    }
    /**
     * Returns the value of the given property in the map
     */
    public static Object value(Map<String,Object> map, String key, Object defaultValue) {
        Object obj = map.get(key);
        if (obj == null) {
            return defaultValue;
        } else {
            return obj;
        }
    }

    /**
     * Returns the String value of the given property in the map or null
     */
    public static String stringValue(Map map, String key) {
        return stringValue(map, key, null);
    }

    /**
     * Returns the String value of the given property in the map if its defined or the default value
     */
    public static String stringValue(Map map, String key, String defaultValue) {
        Object obj = map.get(key);
        if (obj == null) {
            return defaultValue;
        } else if (obj instanceof String) {
            return (String) obj;
        } else {
            return String.valueOf(obj);
        }
    }

    /**
     * Sets the value in the map for the given key; if the value is null then remove the value from the map
     */
    public static void setValue(Map map, String key, Object value) {
        if (value != null) {
            map.put(key, value);
        } else {
            map.remove(key);
        }
    }

    /**
     * Returns the string values for the given key. If the value is a String then it is split using a comma
     */
    public static String[] stringValues(Map map, String key) {
        Object obj = map.get(key);
        if (obj instanceof String[]) {
            return (String[]) obj;
        } else if (obj instanceof String) {
            String text = (String) obj;
            return text.split(",");
        }
        return null;
    }

    /**
     * Sets the string values in the map for the given key, using a comma to separate the values as a String
     */
    public static void setStringValues(Map map, String key, String[] values) {
        if (values != null) {
            String text = Arrays.join(",", values);
            map.put(key, text);
        } else {
            map.remove(key);
        }
    }

    /**
     * Returns a list of values for the given key. If its not a list then just return a single value as a List
     */
    public static List listValue(Map<String, Object> map, String key) {
        Object value = null;
        if (map != null) {
            value = map.get(key);
        }
        if (value instanceof List) {
            return (List) value;
        } else if (value instanceof Object[]) {
            return java.util.Arrays.asList((Object[]) value);
        } else if (value != null) {
            List list = new ArrayList();
            list.add(value);
            return list;
        }
        return null;
    }


    public static String valueAsString(Map<String, Object> map, String key) {
        if (map != null) {
            Object value = valueOrNull(map, key);
            if (value != null) {
                return value.toString();
            }
        }
        return null;
    }

    public static String nestedValueAsString(Map<String, Object> map, String... names) {
        int lastIdx = names.length -1;
        for (int i = 0; i < lastIdx; i++) {
            if (map == null) {
                return null;
            }
            map = (Map<String, Object>) value(map, names[i], null);
        }
        return valueAsString(map, names[lastIdx]);
    }

    /**
     * Parses text from an environment variable of the form "key=value,key2=value2" into a Map
     */
    public static LinkedHashMap<String, String> parseMap(String text) {
        LinkedHashMap<String, String> answer = new LinkedHashMap<>();
        if (Strings.isNotBlank(text)) {
            String[] entries = text.split(",");
            if (entries != null) {
                for (String entry : entries) {
                    String[] values = entry.split("=", 2);
                    if (values != null && values.length == 2) {
                        answer.put(values[0], values[1]);
                    }
                }
            }
        }
        return answer;
    }
}