public class TreeMap extends AbstractMap implements NavigableMap, Cloneable, Serializable

import java.util.*;
class TreeMap1{
 public static void main(String args[]){
   TreeMap map=new TreeMap();  
  map.put(100,"Amit");  
  map.put(102,"Ravi");  
  map.put(101,"Vijay");  
  map.put(103,"Rahul");  
  
  for(Map.Entry m:map.entrySet()){  
   System.out.println(m.getKey()+" "+m.getValue());  
  }  
 }
}

Output:100 Amit
       101 Vijay
       102 Ravi
       103 Rahul

import java.util.*;
public class TreeMap2 {
   public static void main(String args[]) {
TreeMap map=new TreeMap();  
  map.put(100,"Amit");  
  map.put(102,"Ravi");  
  map.put(101,"Vijay");  
  map.put(103,"Rahul");  
  System.out.println("Before invoking remove() method");
  for(Map.Entry m:map.entrySet())
  {
  System.out.println(m.getKey()+" "+m.getValue());  
  }
  map.remove(102);  
  System.out.println("After invoking remove() method");
  for(Map.Entry m:map.entrySet())
  {
  System.out.println(m.getKey()+" "+m.getValue());  
  }
  }
}

Before invoking remove() method
100 Amit
101 Vijay
102 Ravi
103 Rahul
After invoking remove() method
100 Amit
101 Vijay
103 Rahul

import java.util.*;
class TreeMap3{
 public static void main(String args[]){
   NavigableMap map=new TreeMap();  
  map.put(100,"Amit");  
  map.put(102,"Ravi");  
  map.put(101,"Vijay");  
  map.put(103,"Rahul");  
  //Maintains descending order
  System.out.println("descendingMap: "+map.descendingMap());
  //Returns key-value pairs whose keys are less than or equal to the specified key.
  System.out.println("headMap: "+map.headMap(102,true));
  //Returns key-value pairs whose keys are greater than or equal to the specified key.
  System.out.println("tailMap: "+map.tailMap(102,true));
  //Returns key-value pairs exists in between the specified key.
  System.out.println("subMap: "+map.subMap(100, false, 102, true)); 
 }
}

descendingMap: {103=Rahul, 102=Ravi, 101=Vijay, 100=Amit}
headMap: {100=Amit, 101=Vijay, 102=Ravi}
tailMap: {102=Ravi, 103=Rahul}
subMap: {101=Vijay, 102=Ravi}

import java.util.*;
class TreeMap4{
 public static void main(String args[]){
   SortedMap map=new TreeMap();  
  map.put(100,"Amit");  
  map.put(102,"Ravi");  
  map.put(101,"Vijay");  
  map.put(103,"Rahul");  
  //Returns key-value pairs whose keys are less than the specified key.
  System.out.println("headMap: "+map.headMap(102));
  //Returns key-value pairs whose keys are greater than or equal to the specified key.
  System.out.println("tailMap: "+map.tailMap(102));
  //Returns key-value pairs exists in between the specified key.
  System.out.println("subMap: "+map.subMap(100, 102));  
 }
}

headMap: {100=Amit, 101=Vijay}
tailMap: {102=Ravi, 103=Rahul}
subMap: {100=Amit, 101=Vijay}

import java.util.*;  
class Book {  
int id;  
String name,author,publisher;  
int quantity;  
public Book(int id, String name, String author, String publisher, int quantity) {  
    this.id = id;  
    this.name = name;  
    this.author = author;  
    this.publisher = publisher;  
    this.quantity = quantity;  
}  
}  
public class MapExample {  
public static void main(String[] args) {  
    //Creating map of Books  
    Map map=new TreeMap();  
    //Creating Books  
    Book b1=new Book(101,"Let us C","Yashwant Kanetkar","BPB",8);  
    Book b2=new Book(102,"Data Communications & Networking","Forouzan","Mc Graw Hill",4);  
    Book b3=new Book(103,"Operating System","Galvin","Wiley",6);  
    //Adding Books to map 
    map.put(2,b2);
    map.put(1,b1);
    map.put(3,b3);
    
    //Traversing map
    for(Map.Entry entry:map.entrySet()){  
    int key=entry.getKey();
    Book b=entry.getValue();
        System.out.println(key+" Details:");
        System.out.println(b.id+" "+b.name+" "+b.author+" "+b.publisher+" "+b.quantity); 
    }  
}  
}  

1 Details:
101 Let us C Yashwant Kanetkar BPB 8
2 Details:
102 Data Communications & Networking Forouzan Mc Graw Hill 4
3 Details:
103 Operating System Galvin Wiley 6