Java 中 HashMap 转换为 TreeMap 的程序
java 8object oriented programmingprogramming更新于 2025/12/9 8:12:17
首先创建一个 HashMap −
Map<String, String> map = new HashMap<>();
map.put("1", "One");
map.put("2", "Two");
map.put("3", "Three");
map.put("4", "Four");
map.put("5", "Five");
map.put("6", "Six");
现在，将上面的 HashMap 转换为 TreeMap −
Map<String, String> treeMap = new TreeMap<>(); treeMap.putAll(map);
示例
以下是 Java 中将 HashMap 转换为 TreeMap 的程序 −
import java.util.*;
import java.util.stream.*;
public class Demo {
public static void main(String args[]) {
Map<String, String> map = new HashMap<>();
map.put("1", "One");
map.put("2", "Two");
map.put("3", "Three");
map.put("4", "Four");
map.put("5", "Five");
map.put("6", "Six");
map.put("7", "Seven");
map.put("8", "Eight");
map.put("9", "Nine");
System.out.println("HashMap = " + map);
Map<String, String> treeMap = new TreeMap<>();
treeMap.putAll(map);
System.out.println("TreeMap (HashMap to TreeMap) " + treeMap);
}
}
输出
HashMap = {1=One, 2=Two, 3=Three, 4=Four, 5=Five, 6=Six, 7=Seven, 8=Eight, 9=Nine}
TreeMap (HashMap to TreeMap) {1=One, 2=Two, 3=Three, 4=Four, 5=Five, 6=Six, 7=Seven, 8=Eight, 9=Nine}
