在Java中使用 TreeMap 对用户定义的对象进行排序

给出的示例显示了如何对用户定义的对象 TreeMap 进行排序，您可以根据方法内部提供的逻辑对键进行排序。
给定员工姓名和薪水为正整数的记录，需要使用Java中的 TreeMap 根据员工薪水对记录进行排序。如果工资相同，则使用员工姓名进行比较。

例子：

Input : xbnnskd 100 geek 50
Output : geek 50 xbnnskd 100

Input : shyam 50 ram 50
Output : ram 50 shyam 50
Explanation : 
As both the employees have equal pay, 
sorting is done on the basis of employee's name.

方法：

1. Traverse through the string 
   and map the employee's salary(S)
   with the list of employee names having salary S.
2. Use a TreeMap to have 
   keys(Employee's Salary) in a sorted manner.
3. Now, Traverse through the map 
   and print the sorted records.

以下是上述方法的实现：

// Java program to print employees
// records in a sorted manner
  
import java.io.*;
import java.util.*;
  
public class GFG {
  
    // Function to sort the records
    static void sortRecords(String records)
    {
  
        // split the string
        // on the basis of delimiter space(" ")
        String[] rec = records.split(" ");
  
        // Create a Treemap to store
        // employee's salary with employee's name
        Map > map = new TreeMap<>();
  
        // Traverse the records array
        // and store values in map
        for (int i = 1; i < rec.length; i += 2) {
  
            // Converting String to integer
            int sal = Integer.parseInt(rec[i]);
  
            String name = rec[i - 1];
  
            if (map.containsKey(sal)) {
  
                ArrayList al = map.get(sal);
                al.add(name);
  
                // Sorting list of employees having Salary sal
                Collections.sort(al);
                map.remove(sal);
                map.put(sal, al);
            }
            else {
                ArrayList al = new ArrayList<>();
                al.add(name);
                map.put(sal, al);
            }
        }
  
        // Traversing the map
        // to print the sorted records
        for (Map.Entry >
                 entry : map.entrySet()) {
  
            ArrayList al1 = entry.getValue();
  
            for (int i = 0; i < al1.size(); i++)
                System.out.print(al1.get(i) + " "
                                 + entry.getKey() + " ");
        }
    }
  
    // Driver code
    public static void main(String args[])
    {
       String records = "Harsh 100 Neha 100 Neha 20 Samay 600 Karan 50";
        // Calling function to sort the records
        sortRecords(records);
    }
}

输出：

Neha 20 Karan 50 Harsh 100 Neha 100 Samay 600