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What is the purpose of MapUtils in Apache Commons Collections?
MapUtils provides static helpers for working with Map instances, focused on null-safety and type-safe value extraction.
Methods like getString(map, key, defaultValue), getInteger(), and getBoolean() pull a value out, cast it to the expected type, and fall back to a supplied default if the key is missing or the value can't be converted - avoiding a raw ClassCastException or manual null-check chain.
Map<String, Object> config = new HashMap<>(); config.put("retries", "3"); int retries = MapUtils.getIntValue(config, "retries", 1); boolean isEmpty = MapUtils.isEmpty(config);
It also offers invertMap() to swap keys and values, and unmodifiableMap()/synchronizedMap() decorators mirroring the JDK's own but consistent with the rest of the Commons Collections API.
MapUtils.getIntValue(map, key, defaultValue) is useful because it:
Which MapUtils method swaps a map's keys and values?
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