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Articles on Trending Technologies
Technical articles with clear explanations and examples
C++ Program to Decode a Message Encoded Using Playfair Cipher
In this scheme, pairs of letters are encrypted, instead of single letters as in the case of simple substitution cipher.In playfair cipher, initially a key table is created. The key table is a 5×5 grid of alphabets that acts as the key for encrypting the plaintext. Each of the 25 alphabets must be unique and one letter of the alphabet (usually J) is omitted from the table as we need only 25 alphabets instead of 26. If the plaintext contains J, then it is replaced by I.The sender and the receiver deicide on a particular key, say ‘tutorials’. In a ...
Read MoreHow can I intercept the Status Bar Notifications in Android?
This example demonstrate about How can I intercept the Status Bar Notifications in AndroidStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to src/MyListener.javapublic interface MyListener { void setValue (String packageName) ; }Step 3 − Add the following code to src/MyListener.javapackage app.tutorialspoint.com.notifyme ; import android.content.Context ; import android.service.notification.NotificationListenerService ; import android.service.notification.StatusBarNotification ; import android.util.Log ; public class NotificationService extends NotificationListenerService { private String TAG = this .getClass().getSimpleName() ; Context context ; static MyListener ...
Read MoreI/O Redirection in C++
In C, we can use the freopen() function for redirection purposes. Using this function, we can redirect existing FILE pointer to another stream. The syntax of the freopen is like below:FILE *freopen(const char* filename, const char* mode, FILE *stream)In C++ also, we can do the redirection. In C++, the streams are used. Here we can use our own stream, and also redirect system streams. In C++, there are three types of streams.istream : Stream, that can support input onlyostream : Stream, that can support output onlyiostream : These can be used for input and output.These classes, and file stream classes ...
Read MoreHow does generic lambda work in C++14?
In C++11, the lambda was introduced. Lambdas are basically a part of, that can be nested inside other function call statements. By combining lambda expressions with the auto keyword, they can be used later.In C++14, these lambda expressions are improved. Here we can get the generalized or generic lambda. For example, if we want to create a lambda, that can add integers, add numbers, also concatenate strings, then we have to use this generalized lambda.Syntax of the lambda expression is looking like this −[](auto x, auto y) { return x + y; }Let us see one example to get the ...
Read MoreHow to detect a new Android notification?
This example demonstrate about How to detect a new Android notificationStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to src/MyListener.javapublic interface MyListener { void setValue (String packageName) ; }Step 3 − Add the following code to src/MyListener.javapackage app.tutorialspoint.com.notifyme ; import android.content.Context ; import android.service.notification.NotificationListenerService ; import android.service.notification.StatusBarNotification ; import android.util.Log ; public class NotificationService extends NotificationListenerService { private String TAG = this .getClass().getSimpleName() ; Context context ; static MyListener myListener ; @Override ...
Read MoreJava Program to set different height for multiple rows in JTable
To set different height for multiple rows, use the setRowHeight() method for separate rows for which you want to increase the row height. Let us first see an example to create a table with same height for all the rows −Examplepackage my; import java.awt.Color; import java.awt.Font; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.table.DefaultTableModel; public class SwingDemo { public static void main(String[] argv) throws Exception { DefaultTableModel tableModel = new DefaultTableModel(); JTable table = new JTable(tableModel); tableModel.addColumn("Language/ Technology"); tableModel.addColumn("Text Tutorial"); tableModel.addColumn("Video Tutorial"); ...
Read MoreMySQL automatic conversion on lowercase? Is this possible?
Yes, it is possible with triggers. You can create trigger for automatic conversion on lower case. Let us first create a table −mysql> create table DemoTable ( StudentSubject text ); Query OK, 0 rows affected (0.61 sec)Let us create a trigger for automatic conversion on lower case −mysql> CREATE TRIGGER lowerCaseOnInsertDemo BEFORE INSERT ON DemoTable FOR EACH ROW SET NEW.StudentSubject = LOWER(NEW.StudentSubject); Query OK, 0 rows affected (0.21 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('MOngoDb'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('JaVA'); Query OK, ...
Read MoreHow to count element after filtering in Java?
Let’s say the following is the String List:List list = new ArrayList(); list.add("Tom"); list.add("John"); list.add("David"); list.add("Paul"); list.add("Gayle"); list.add("Narine"); list.add("Joseph");Now, let’s say you need to filter elements beginning with a specific letter. For that, use filter() and startsWith():long res = list .stream() .filter((s) -> s.startsWith("J")) .count();We have also counted the elements above after filtering using count().The following is an example to count element after filtering in Java:Exampleimport java.util.ArrayList; import java.util.List; public class Demo { public static void main(final String[] args) { List list = new ArrayList(); list.add("Tom"); list.add("John"); ...
Read MoreC++ Program to Implement the Hill Cypher
Based on linear algebra Hill cipher is a polygraphic substitution cipher in cryptography.To encrypt message: The key string and message string are represented as matrix form. They are multiplied then, against modulo 26. The key matrix should have inverse to decrypt the message.To decrypt message: The encrypted message is multiplied by inverse key matrix used for encryption against modulo 26 to get decrypt message.For exampleKey matrix1 0 1 2 4 0 3 5 6Message string ‘ABC’ in matrix form −0 1 2For encryptionAfter multiplying above two matrices we get, 2 4 17Which will be the encrypted message ‘CER’For decryptionInverse of ...
Read MoreHow to apply NOW() to timestamps field in MySQL Workbench?
Let us first create a table −create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, ShippingDate timestamp );Insert some records in the table using insert command. Here, we have included the current date with NOW() −INSERT INTO DemoTable(ShippingDate) VALUES(now());Display all records from the table using select statement −SELECT *FROM DemoTable;OutputFollowing is the screenshot of query in MySQL workbench to set NOW() to timestamp field “ShippingDate”. The query also displays the output below −
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