HashMap排序问题详解编程语言

package com.icos.utility.listsort; 
 
import java.util.ArrayList; 
import java.util.Comparator; 
import java.util.HashMap; 
import java.util.Map; 
import java.util.Map.Entry; 
import java.util.TreeMap; 
 
/** 
 * @给出一个集合，排一个叙出来 
 *  
 * */ 
public class CustomSort { 
	/** 
	 * @Function 降序排 
	 *  
	 * */ 
	public static TreeMap<String, Float> sortFloatDESC(HashMap<String, Float> map) { 
		ValueComparatorDesc valComp = new ValueComparatorDesc(map); 
		TreeMap<String, Float> sortedMap = new TreeMap<String, Float>(valComp); 
		sortedMap.putAll(map); 
		return sortedMap; 
	} 
	 
	/** 
	 * @Function 升序排 
	 *  
	 * */ 
	public static TreeMap<String, Float> sortFloatASC(HashMap<String, Float> map) { 
		ValueComparatorAsc valComp = new ValueComparatorAsc(map); 
		TreeMap<String, Float> sortedMap = new TreeMap<String, Float>(valComp); 
		 
		sortedMap.putAll(map); 
		 
		return sortedMap; 
	} 
	 
	public static void main(String[] args){ 
		HashMap<String, Float> map = new HashMap<String,Float>(); 
		map.put("A", (float) 0.9999); 
		map.put("B", (float) 0.111); 
		map.put("C", (float) 1.9090); 
		map.put("D", (float) 0.2); 
		 
		CustomSort sf = new CustomSort(); 
		System.out.println(sf.sortFloatDESC(map)); 
	} 
	 
	 
	/** 获取一个连续数组，最大的那个数组  
	 * @return */ 
	public static Integer[] getMaxCNumber(Integer[] array){ 
		ArrayList<Integer> maxArrays = new ArrayList<Integer>(); 
		ArrayList<Integer> nowArrays = new ArrayList<Integer>(); 
		// {0, 1, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23}; 
		int max = array[0] - 1; 
		for (int i = 0; i < array.length; i++) { 
//			System.out.println("array[i]: "+array[i] + " ; max+1: "+(max+1)); 
			if (array[i] != max + 1) { 
				max = array[i] - 1; 
//				System.out.println("--------------------------------,max="+(array[i] - 1) + " ;array[i]="+array[i]); 
				nowArrays.clear(); 
			} 
 
			nowArrays.add(array[i]); 
			max = array[i]; 
 
			if (nowArrays.size() >= maxArrays.size()) { 
				// maxArrays=nowArrays;这种情况是吧nowdays的地址赋值给了maxarrays的地址，这样以后只要nowarrays的地址改变，maxarrays的值也会改变 
				maxArrays = (ArrayList<Integer>) nowArrays.clone(); 
//				System.out.println("nowArrays: "+nowArrays.toString()); 
//				System.out.println("maxArrays: "+maxArrays.toString()); 
			} 
		} 
 
		return (Integer[]) maxArrays.toArray(new Integer[] {}); 
	} 
} 
 
/** 
 * @Function 降序排，从大到小 
 *  
 * */ 
class ValueComparatorDesc implements Comparator<String> { 
 
	Map<String, Float> mapFloat; 
 
	// 这里需要将要比较的map集合传进来 
	public ValueComparatorDesc(Map<String, Float> mapFloat) { 
		this.mapFloat = mapFloat; 
	} 
 
	public int compare(String a, String b) { 
		if (mapFloat.get(a) >= mapFloat.get(b)) { 
			return -1; 
		} else { 
			return 1; 
		} 
	} 
} 
 
/** 
 * @Function 升序排，从小到大 
 *  
 * */ 
class ValueComparatorAsc implements Comparator<String> { 
 
	Map<String, Float> mapFloat; 
 
	// 这里需要将要比较的map集合传进来 
	public ValueComparatorAsc(Map<String, Float> mapFloat) { 
		this.mapFloat = mapFloat; 
	} 
 
	public int compare(String a, String b) { 
		if (mapFloat.get(a) <= mapFloat.get(b)) { 
			return -1; 
		} else { 
			return 1; 
		} 
	} 
}