Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Articles on Trending Technologies
Technical articles with clear explanations and examples
How to retrieve binary data from a table using JDBC?
SQL databases provide a datatype named Blob (Binary Large Object) in this, you can store large binary data like images.To retrieve binary (stream) values from a table JDBC provides a method called getBinaryStream() in the PreparedStatement interface.It accepts an integer representing the index of the column of the table and retrieves the binary data from it.You can retrieve binary data from a table using this method as shown below −FileInputStream fin = new FileInputStream("javafx_logo.jpg"); pstmt.setBinaryStream(3, fin);ExampleLet us create a table with name tutorials_data in MySQL using the CREATE statement as shown below −CREATE TABLE tutorials_data( Name VARCHAR(255), Type ...
Read MoreSort String Array alphabetically by the initial character only in Java
Here, we are sorting string array alphabetically by the initial character i.e. ‘J’ for ‘John’ will come after ‘Chris’ since the first character of ‘Chris’ is ‘C’.Let us first create a String array:String[] strArr = { "PQRS", "AB", "RSTUVW", "RST", "U", "UVWXY", "OUJBG" };Now, sort the string array based on the first character:Arrays.sort(strArr, (str1, str2) -> str1.charAt(0) - str2.charAt(0));The following is an example to sort String Array alphabetically by the initial character only:Exampleimport java.util.Arrays; public class Demo { public static void main(String[] args) { String[] strArr = { "PQRS", "AB", "RSTUVW", "RST", "U", "UVWXY", "OUJBG" }; ...
Read MoreExcept not working in MySQL?
You cannot use except in MySQL. You can work with NOT IN operator to get the same result. Let us first create a table −mysql> create table DemoTable1 ( Number1 int ); Query OK, 0 rows affected (0.71 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1 values(100); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1 values(200); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1 values(300); Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement:mysql> select *from DemoTable1This will produce the following output −+---------+ | Number1 | +---------+ | 100 | | 200 | | 300 | +---------+ 3 rows in set (0.00 sec)Following ...
Read MoreHow can I set scrollbars to never appear in Java?
To set scrollbars to never appear, use the JScrollPane.HORIZONTAL_SCROLLBAR_NEVER and JScrollPane.VERTICAL_SCROLLBAR_NEVER. Let’s say you created a Box with some button components. Now, create a JScrollPane:JScrollPane scrollPane = new JScrollPane();Set the Viewport view as Box:scrollPane.setViewportView(box);Now, set the scrollbars to never appear:scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_NEVER);The following is an example to set scrollbars to never appear:Examplepackage my; import java.awt.BorderLayout; import java.awt.Dimension; import javax.swing.Box; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JScrollPane; public class SwingDemo { public static void main(String args[]) { JFrame frame = new JFrame("Demo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JButton button1 = new JButton("One"); JButton button2 ...
Read MoreTake off last character if a specific one exists in a string?
You can use trim() for this.Let us first create a table −mysql> create table DemoTable ( UserId varchar(100) ); Query OK, 0 rows affected (0.63 sec)Insert some records in the table using insert command. Here, we have added a question mark (?) to the end of some of the strings −mysql> insert into DemoTable values('User123?'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('User777'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('User456'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('User133?'); Query OK, 1 ...
Read MoreRetrieving MySQL Database structure information from Java?
Use DatabaseMetaData class to retrieve MySQL database structure. In this example, we will display all the table names of database “web” using Java with the help of getMetaData().Following is the Java code −Exampleimport java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; import com.mysql.jdbc.DatabaseMetaData; public class getDatabaseInformationDemo { public static void main(String[] args) { Connection con = null; try { con = DriverManager.getConnection("jdbc:mysql://localhost:3306/web?useSSL=false", "root", "123456"); DatabaseMetaData information = (DatabaseMetaData) con.getMetaData(); String allTableName[] = { "TABLE" ...
Read MoreHow to add tooltip to JLabel in Java?
Tooltip is visible whenever you will place the mouse cursor on the label. Use the setToolTipText() method to add tooltip to JLabel −label.setToolTipText("This is a demo tooltip");The following is an example to add tooltip to JLabel −Exampleimport java.awt.Color; import java.awt.Font; import javax.swing.*; import javax.swing.border.Border; public class SwingDemo { public static void main(String args[]) { JFrame frame = new JFrame("Demo"); JLabel label; label = new JLabel("Demo Label!"); label.setFont(new Font("Verdana", Font.PLAIN, 14)); label.setToolTipText("This is a demo tooltip"); Border border = BorderFactory.createLineBorder(Color.ORANGE); ...
Read MoreWhat is the Java equivalent to MySQL's smallint?
The short is equivalent to MySQL’s small int. The Java short takes 2 bytes that has the range -32768 to 32767 while MySQL smallint also take 2 bytes with same range.Here is the demo code of short in Java −public class SmallIntAsShortDemo { public static void main(String[] args) { short value = 32767; System.out.println(value); value = -32768; System.out.println(value); // value = 32768; // System.out.println(value); } }The snapshot is as follows −This will produce the following output −32767 -32768Here is the snapshot of the output we ran in EclipseIDE −The MySQL smallint takes 2 bytes with same range.
Read MoreHow to run a timer in background within your iOS app
If you wish to run a timer in background within your iOS Application, Apple provides beginBackgroundTaskWithExpirationHandler method, you can read more about the same developer.apple.com/documentation/uikit/uiapplication/1623031-beginbackgroundtaskwithexpiration.We will be using the same for writing our code for running the timer in background.So let’s begin.Step 1 − Open Xcode → Single View Application → Let’s name is BackgroundTimer.Step 2 − Open AppDelegate.swift and under method applicationDidEnterBackground write the below code.backgroundTaskIdentifier = UIApplication.shared.beginBackgroundTask(expirationHandler: { UIApplication.shared.endBackgroundTask(self.backgroundTaskIdentifier!) }) _ = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(self.doSomething), userInfo: nil, repeats: true)Step 3 − Write new function doSomething()@objc func doSomething() { print("I'm running") }Finally your code should look like belowfunc applicationDidEnterBackground(_ application: UIApplication) { backgroundTaskIdentifier = UIApplication.shared.beginBackgroundTask(expirationHandler: { ...
Read MoreHow to get the properties of a driver using JDBC?
You can get the properties of a driver using the getPropertyInfo() method of the Driver interface.DriverPropertyInfo[] info = driver.getPropertyInfo(mysqlUrl, null);This method accepts a two parameters: A String variable representing the URL of the database, an object of the class Properties and, returns an array of the DriverPropertyInfo objects, where each object holds information about the possible properties of the current driver.From a DriverPropertyInfo object you can get the information such as name of the property, value of the property, description, choices and, if it is required or not, using its fields name, value, description, choices, required, respectively.DriverPropertyInfo[] info = driver.getPropertyInfo(mysqlUrl, ...
Read More