TREEMAP detailed analysis and usage example in Jin Collections

Jin Collections is a commonly used Java class library, where TREEMAP provides an orderly mapping based on red and black trees.This article will analyze the use of TreeMap in detail and provide some Java code examples. TREEMAP is a implementation class of the MAP interface. It is essentially sorting the key values according to the natural order of the key or custom order.It uses red and black trees as the underlying data structure to maintain the orderly pair of key values, which makes TreeMap find a better balance point in order of order and efficiency. Using TreeMap needs to import java.util package. The code is as follows: import java.util.TreeMap; public class TreeMapExample { public static void main(String[] args) { // Create a timeMap object TreeMap<Integer, String> treeMap = new TreeMap<>(); // Insert the key value to the keymap pair treeMap.put(3, "Apple"); treeMap.put(1, "Banana"); treeMap.put(4, "Orange"); treeMap.put(2, "Mango"); // Print the key value pair in timeMap for (Integer key : treeMap.keySet()) { System.out.println("Key: " + key + ", Value: " + treeMap.get(key)); } // Get the first and last key value pair of timemap System.out.println("First Entry: " + treeMap.firstEntry()); System.out.println("Last Entry: " + treeMap.lastEntry()); // Get the sub -mapping of timemap System.out.println("SubMap: " + treeMap.subMap(1, 3)); // Delete the key value pair treeMap.remove(2); // Trim whether the timeMap contains a certain key System.out.println("Contains Key 2: " + treeMap.containsKey(2)); // Judging whether timemap contains a certain value System.out.println("Contains Value Apple: " + treeMap.containsValue("Apple")); // Judging whether timemap is empty System.out.println("Is Empty: " + treeMap.isEmpty()); // Get the quantity of the key in the treemap System.out.println("Size: " + treeMap.size()); } } The above code first created a TreeMap object, and inserted some key values into the timeMap through the `Put` method.Then use the `KeySet` method to get the set of all keys, and use an enhanced for loop to traverse the output key value pair.Then obtain the first and last key values pairs of timemap through the method of `FIRTENTRY` and LaistenTry`.Also use the `submap` method to obtain sub -mapping specified in the specified range.Then, the code demonstrates how to delete the key value pair and use the method of `containskey` and` containsValue` to determine whether the timeMap contains a certain key or value.Finally, use the `isempty` and` size` methods to determine whether the timemap is empty and the number of obtained bonds, respectively. Through TreeMap examples, we can understand the basic operations and usage methods of this class. According to the actual needs, we can flexibly use TreeMap to achieve orderly mapping functions.