map的简单工具类

MapHelper.java

/**
 * A bunch of utility methods for working with maps
 * 
 * 
 */
public final class MapHelper {

    private MapHelper() {
    }

    /**
     * Extracts the value from the map and coerces to a String
     */
    public static String getString(Map map, String key) {
        Object answer = map.get(key);
        return (answer != null) ? answer.toString() : null;
    }

    /**
     * Extracts the value from the map and coerces to an int value or returns a
     * default value if one could not be found or coerced
     */
    public static int getInt(Map map, String key, int defaultValue) {
        Object value = map.get(key);
        if (value instanceof Number) {
            return ((Number)value).intValue();
        } else if (value instanceof String) {
            return Integer.parseInt((String)value);
        }
        return defaultValue;
    }
}