JAVA EXAMPLE PROGRAMS

JAVA EXAMPLE PROGRAMS

Publish Your Article Here

Program: How to copy Map content to another Hashtable?


Description:

Below example shows how to copy another collection object to Hashtable. Below example copies all HashMap entries to Hashtable. putAll() method helps us to copy another collection object.


Code:
package com.java2novice.hashtable;

import java.util.HashMap;
import java.util.Hashtable;

public class MyHashtableCopy {

	public static void main(String a[]){
		Hashtable<String, String> hm = new Hashtable<String, String>();
		//add key-value pair to Hashtable
		hm.put("first", "FIRST INSERTED");
		hm.put("second", "SECOND INSERTED");
		hm.put("third","THIRD INSERTED");
		System.out.println(hm);
		HashMap<String, String> subMap = new HashMap<String, String>();
		subMap.put("s1", "S1 VALUE");
		subMap.put("s2", "S2 VALUE");
		hm.putAll(subMap);
		System.out.println(hm);
	}
}

Output:
{third=THIRD INSERTED, second=SECOND INSERTED, first=FIRST INSERTED}
{s2=S2 VALUE, third=THIRD INSERTED, second=SECOND INSERTED, s1=S1 VALUE, first=FIRST INSERTED}
<< Previous Program | Next Program >>

List Of All Hashtable Sample Programs:

  1. Basic Hashtable Operations.
  2. How to iterate through Hashtable?
  3. How to copy Map content to another Hashtable?
  4. How to search a key in Hashtable?
  5. How to search a value in Hashtable?
  6. How to get all keys from Hashtable?
  7. How to get entry set from Hashtable?
  8. How to delete all elements from Hashtable?
  9. How to read elements using Enumeration in Hashtable?
  10. Hashtable implementation with equals and hashcode example.
  11. How to fetch values with user define object as keys in Hashtable?
  12. How to eliminate duplicate keys (user defined objects) with Hashtable?
Knowledge Centre
ServletOuptputStream Vs PrintWriter
ServletOutputStream: ServletResponse.getOutputStream() returns a ServletOutputStream suitable for writing binary data in the response. The servlet container does not encode the binary data, it sends the raw data as it is.

PrintWriter: ServletResponse.getWriter() returns PrintWriter object which sends character text to the client. The PrintWriter uses the character encoding returned by getCharacterEncoding(). If the response's character encoding has not been specified then it does default character encoding.
Famous Quotations
Education is what remains after one has forgotten what one has learned in school.
-- Albert Einstein

About Author

I'm Nataraja Gootooru, programmer by profession and passionate about technologies. All examples given here are as simple as possible to help beginners. The source code is compiled and tested in my dev environment.

If you come across any mistakes or bugs, please email me to [email protected].

Most Visited Pages

Other Interesting Sites

Reference: Java™ Platform Standard Ed. 7 - API Specification | Java™ Platform Standard Ed. 8 - API Specification | Java is registered trademark of Oracle.
Privacy Policy | Copyright © 2019 by Nataraja Gootooru. All Rights Reserved.