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A new empty file with the required abstract path name can be created using the method java.io.File.createNewFile(). This method requires no parameters and it returns true if the file is newly created and it did not exist previously. If the file existed previously, it returns false.A program that demonstrates this is given as follows −Example Live Demoimport java.io.File; public class Demo { public static void main(String[] args) { try { File file = new File("demo1.txt"); file.createNewFile(); System.out.println("File: " + file); } catch(Exception ... Read More
To get the creation date of MySQL table, use the information_schema. The syntax is as follows −SELECT create_time FROM INFORMATION_SCHEMA.TABLES WHERE table_schema = 'yourDatabaseName’ AND table_name = 'yourTableName';Apply the above syntax for your database and the table name. Here I am using the database ‘business’ and table name is ‘student’. The query is as follows −mysql> SELECT create_time FROM INFORMATION_SCHEMA.TABLES -> WHERE table_schema = 'business' -> AND table_name = 'student';The following is the output displaying the creation time of a table −+---------------------+ | CREATE_TIME ... Read More
To get difference between two timestamps in seconds, use two in-built functions TIME_TO_SEC() and TIMEDIFF() in MySQL. The syntax is as follows −select time_to_sec(timediff(yourCoulnName1, yourCoulnName2)) as anyVariableName from yourTableName;To understand the above concept, let us first create a table. The query to create a table.mysql> create table TimeToSecond −> ( −> MyTime timestamp, −> YourTime timestamp −> ); Query OK, 0 rows affected (0.48 sec)Now you can insert some datetime values in the table. The query is as follows −mysql> insert into TimeToSecond values('2016-05-10 10:02:00', '2016-05-10 10:00:00'); Query ... Read More
Use the get() method to get the value associated with a given key.Here is our HashMap and its elements −// Create a hash map HashMap hm = new HashMap(); // Put elements to the map hm.put("Bag", new Integer(1100)); hm.put("Sunglasses", new Integer(2000)); hm.put("Frames", new Integer(800)); hm.put("Wallet", new Integer(700)); hm.put("Belt", new Integer(600));To get the associated value. the key is set as a parameter like this −hm.get("Frames")Above, the key is Frames and we are fetching the value associated with it.The following is an example to get the value associated with a given key in Java HashMap −Example Live Demoimport java.util.*; public class Demo { ... Read More
The engineering societies such as AAES, ABET, NSPE, IEEE, and AICTE have framed these codes of ethics which are helpful to engineers to strengthen the moral issues on their work. The codes of ethics play at least eight important roles such as the following.Serving and Protecting the PublicEngineers are in a responsible position where trust and trustworthiness, both are essential. A code of ethics functions as a commitment to the profession as a whole that engineers will serve the public health, safety, and welfare. All the remaining ones contribute to this function in some or other way.GuidanceCodes are written in ... Read More
Go-Back-N Automatic Repeat reQuest (Go-Back-N ARQ), is a data link layer protocol that uses a sliding window method for reliable and sequential delivery of data frames. It is a case of sliding window protocol having to send window size of N and receiving window size of 1.Working PrincipleGo – Back – N ARQ uses the concept of protocol pipelining, i.e. sending multiple frames before receiving the acknowledgment for the first frame. The frames are sequentially numbered and a finite number of frames. The maximum number of frames that can be sent depends upon the size of the sending window. If ... Read More
First, create a HashMap and add elements to it −// Create a hash map HashMap hm = new HashMap(); // Put elements to the map hm.put("Bag", new Integer(1100)); hm.put("Sunglasses", new Integer(2000)); hm.put("Frames", new Integer(800)); hm.put("Wallet", new Integer(700)); hm.put("Belt", new Integer(600));Now, to modify the value associated with a given key, use the put() method. Here, we are modifying the value for the key “Frames” −hm.put("Frames", "900");The following is an example to modify the value associated with a given key −Example Live Demoimport java.util.*; public class Demo { public static void main(String args[]) { ... Read More
A TreeMap cannot contain duplicate keys. TreeMap cannot contain the null key. However, It can have null values.Let us first see how to create a TreeMap −TreeMap m = new TreeMap();Add some elements in the form of key-value pairs −m.put(1, "India"); m.put(2, "US"); m.put(3, "Australia"); m.put(4, "Netherlands"); m.put(5, "Canada");The following is an example to create a TreeMap and add key-value pairs −Example Live Demoimport java.util.*; public class Demo { public static void main(String args[]) { TreeMap m = new TreeMap(); m.put(1, "India"); m.put(2, "US"); m.put(3, "Australia"); ... Read More
When a new product developed, the Research and Development department initiate and perform an intensive study and get the details to support the project. Research and Development departments help corporations stay ahead of the competition, utilize new technology, and produce goods more efficiently. This is just the purpose of any research.Research PhaseThe research phase includes determining product specifications, production costs, and a production timeline.It contributes to the development, as a scientist or inventor in the field of Science and Technology. The research plan is a map for one’s career as a research science professional.In the medical field, research enables us ... Read More
The java.io.File class has display constants File.separatorChar and File.pathSeparatorChar mainly. The File.separatorChar is ‘/’ and the File.pathSeparatorChar is ‘:’ for Unix.A program that demonstrates this is given as follows −Example Live Demoimport java.io.File; public class Demo { public static void main(String[] args) { try { System.out.println("File.pathSeparatorChar = " + File.pathSeparatorChar); System.out.println("File.separatorChar = " + File.separatorChar); } catch(Exception e) { e.printStackTrace(); } } }The output of the above program is as follows −OutputFile.pathSeparatorChar = : File.separatorChar = /Now let ... Read More