- Java.util Package Classes
- Java.util - Home
- Java.util - ArrayDeque
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- Java.util - BitSet
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- Java.util - GregorianCalendar
- Java.util - HashMap
- Java.util - HashSet
- Java.util - Hashtable
- Java.util - IdentityHashMap
- Java.util - LinkedHashMap
- Java.util - LinkedHashSet
- Java.util - LinkedList
- Java.util - ListResourceBundle
- Java.util - Locale
- Java.util - Observable
- Java.util - PriorityQueue
- Java.util - Properties
- Java.util - PropertyPermission
- Java.util - PropertyResourceBundle
- Java.util - Random
- Java.util - ResourceBundle
- Java.util - ResourceBundle.Control
- Java.util - Scanner
- Java.util - ServiceLoader
- Java.util - SimpleTimeZone
- Java.util - Stack
- Java.util - StringTokenizer
- Java.util - Timer
- Java.util - TimerTask
- Java.util - TimeZone
- Java.util - TreeMap
- Java.util - TreeSet
- Java.util - UUID
- Java.util - Vector
- Java.util - WeakHashMap
- Java.util Package Extras
- Java.util - Interfaces
- Java.util - Exceptions
- Java.util - Enumerations
- Java.util Useful Resources
- Java.util - Useful Resources
- Java.util - Discussion
Java TreeMap floorEntry() Method
Description
The Java TreeMap floorEntry(K key) method is used to return a key-value mapping associated with the greatest key less than or equal to the given key, or null if there is no such key.
Declaration
Following is the declaration for java.util.TreeMap.floorEntry() method.
public Map.Entry<K,V> floorEntry(K key)
Parameters
key − This is the key to be matched.
Return Value
The method call returns an entry with the greatest key less than or equal to key, or null if there is no such key.
Exception
ClassCastException − This exception is thrown if the specified key cannot be compared with the keys currently in the map.
NullPointerException − This exception is thrown if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys.
Getting Floor Key from a TreeMap of Integer, Integer Pairs Example
The following example shows the usage of Java TreeMap floorEntry() method to get the mapping associated with the greatest key less than or equal to the given key. We've created a TreeMap object of Integer,Integer pairs. Then few entries are added, and using floorEntry() we're printing relevant mapping.
package com.tutorialspoint; import java.util.TreeMap; public class TreeMapDemo { public static void main(String[] args) { // creating tree map TreeMap<Integer, Integer> treemap = new TreeMap<>(); // populating tree map treemap.put(2, 2); treemap.put(1, 1); treemap.put(3, 3); treemap.put(6, 6); treemap.put(5, 5); System.out.println("Checking floor entry for 6"); System.out.println("Value is: "+ treemap.floorEntry(6)); } }
Output
Let us compile and run the above program, this will produce the following result.
Checking floor entry for 6 Value is: 6=6
Getting First Key from a TreeMap of Integer, String Pairs Example
The following example shows the usage of Java TreeMap floorEntry() method to get the mapping associated with the greatest key less than or equal to the given key. We've created a TreeMap object of Integer,String pairs. Then few entries are added, and using floorEntry() we're printing relevant mapping.
package com.tutorialspoint; import java.util.TreeMap; public class TreeMapDemo { public static void main(String[] args) { // creating tree map TreeMap<Integer, String> treemap = new TreeMap<>(); // populating tree map treemap.put(2, "two"); treemap.put(1, "one"); treemap.put(3, "three"); treemap.put(6, "six"); treemap.put(5, "five"); System.out.println("Checking floor entry for 6"); System.out.println("Value is: "+ treemap.floorEntry(6)); } }
Output
Let us compile and run the above program, this will produce the following result.
Checking floor entry for 6 Value is: 6=six
Getting First Key from a TreeMap of Integer, Object Pairs Example
The following example shows the usage of Java TreeMap floorEntry() method to get the mapping associated with the greatest key less than or equal to the given key. We've created a TreeMap object of Integer,Student pairs. Then few entries are added, and using floorEntry() we're printing relevant mapping.
package com.tutorialspoint; import java.util.TreeMap; public class TreeMapDemo { public static void main(String[] args) { // creating tree map TreeMap<Integer, Student> treemap = new TreeMap<>(); // populating tree map treemap.put(2, new Student(2, "Robert")); treemap.put(1, new Student(1, "Julie")); treemap.put(3, new Student(3, "Adam")); treemap.put(6, new Student(6, "Julia")); treemap.put(5, new Student(5, "Tom")); System.out.println("Checking floor entry for 6"); System.out.println("Value is: "+ treemap.floorEntry(6)); } } class Student { int rollNo; String name; Student(int rollNo, String name){ this.rollNo = rollNo; this.name = name; } @Override public String toString() { return "[ " + this.rollNo + ", " + this.name + " ]"; } @Override public boolean equals(Object obj) { if(obj == null) return false; Student s = (Student)obj; return this.rollNo == s.rollNo && this.name.equalsIgnoreCase(s.name); } }
Output
Let us compile and run the above program, this will produce the following result.
Checking floor entry for 6 Value is: 6=[ 6, Julia ]
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