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The application object is direct wrapper around the ServletContext object for the generated Servlet and in reality an instance of a javax.servlet.ServletContext object.This object is a representation of the JSP page through its entire lifecycle. This object is created when the JSP page is initialized and will be removed when the JSP page is removed by the jspDestroy() method.By adding an attribute to application, you can ensure that all JSP files that make up your web application have access to it.
The minute of the hour for a particular LocalTime can be obtained using the getMinute() method in the LocalTime class in Java. This method requires no parameters and it returns the minute of the hour in the range of 0 to 59.A program that demonstrates this is given as followsExample Live Demoimport java.time.*; public class Demo { public static void main(String[] args) { LocalTime lt = LocalTime.parse("23:15:30"); System.out.println("The LocalTime is: " + lt); System.out.println("The minute is: " + lt.getMinute()); } }outputThe LocalTime is: 23:15:30 The minute is: 15Now let us ... Read More
An immutable copy of the Period object where some days are subtracted from it can be obtained using the minusDays() method in the Period class in Java. This method requires a single parameter i.e. the number of days to be subtracted and it returns the Period object with the subtracted days.A program that demonstrates this is given as follows:Example Live Demoimport java.time.Period; public class Demo { public static void main(String[] args) { String period = "P5Y7M15D"; Period p1 = Period.parse(period); System.out.println("The Period is: " + p1); Period p2 ... Read More
In data communications, when a receiver receives a message, it sends an acknowledgement back to the sender to notify it about correct receipt of the message. Cumulative acknowledgement is a process in which the receiver sends a single acknowledgement in response to a finite number of frames received. Through this, the receiver acknowledges that it has correctly received all previous frames or packets. When the sender receives an acknowledgement for frame n, it understands correct delivery of frames n – 1, n – 2 and so on.Cumulative acknowledgement is used along with sliding window protocols. It reduces the time and ... Read More
To reset the primary key to 1 after deleting the data, use the following syntaxalter table yourTableName AUTO_INCREMENT=1; truncate table yourTableName;After doing the above two steps, you will get the primary key beginning from 1.To understand the above concept, let us create a table. The query to create a table is as followsmysql> create table resettingPrimaryKeyDemo -> ( -> UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY -> ); Query OK, 0 rows affected (0.66 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into resettingPrimaryKeyDemo values(); Query OK, 1 row ... Read More
The absolute() method of the ResultSet interface accepts an integer value representing the index of a row and moves the ResultSet pointer of the current ResultSet object to the specified position.Assume we have a table named cricketers_data with 6 records as shown below:+------------+------------+---------------+----------------+-------------+ | First_Name | Last_Name | Date_Of_Birth | Place_Of_Birth | Country | +------------+------------+---------------+----------------+-------------+ | Shikhar | Dhawan | 1981-12-05 | Delhi | India | | Jonathan | Trott | 1981-04-22 | CapeTown | SouthAfrica | | Lumara ... Read More
To store query result (a single document) into a variable, you can use var. Following is the syntaxvar anyVariableName=db.yourCollectionName.find().limit(1); yourVariableName; //Print the records;Let us first create a collection with documents> db.storeQueryResultDemo.insertOne({"ClientName":"Chris", "ClientAge":23}); { "acknowledged" : true, "insertedId" : ObjectId("5c9ecf8fd628fa4220163b8d") } > db.storeQueryResultDemo.insertOne({"ClientName":"Robert", "ClientAge":21}); { "acknowledged" : true, "insertedId" : ObjectId("5c9ecf97d628fa4220163b8e") } > db.storeQueryResultDemo.insertOne({"ClientName":"Sam", "ClientAge":25}); { "acknowledged" : true, "insertedId" : ObjectId("5c9ecf9ed628fa4220163b8f") } > db.storeQueryResultDemo.insertOne({"ClientName":"Mike", "ClientAge":26}); { "acknowledged" : true, "insertedId" : ObjectId("5c9ecfa8d628fa4220163b90") }Following is the query to display all documents from a collection with the help of find() method> db.storeQueryResultDemo.find().pretty();This will produce ... Read More
To get maximum and minimum values in a single query, use the aggregate function min() and max(). Let us first create a table:mysql> create table DemoTable ( FirstValue int, SecondValue int ); Query OK, 0 rows affected (0.66 sec)Following is the query to insert some records in the table using insert command:mysql> insert into DemoTable values(10, 30); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(30, 60); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(100, 500); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(50, 80); Query OK, ... Read More
Intel 8255 is a peripheral interface (PPI) chip which is programmable. It is used for the connection of peripheral devices and interfacing. We call Peripheral device also as Input Output device. We use Input Output ports for the connection of Input Output devices. Hence 8255 is a programmable Input Output port chip. It is a 40 pin chip available for dual line packaging. Power supply of +5 Volt DC is needed for its working. It consists of two programmable Input Output ports having of size 8 bits and two programmable Input Output ports of size 4 bits. We call them ... Read More
You can use $unset operator to remove a field completely from a MongoDb document. The syntax is as follows:db.yourCollectionName.update({}, {$unset: {yourFieldName:1}}, false, true);To understand the above syntax, let us create a collection with some documents. The query to create a collection with documents are as follows:> db.removeFieldCompletlyDemo.insertOne({"StudentName":"Larry", "StudentFavouriteSubject": ["Java", "C", "C++", "Python"]}); { "acknowledged" : true, "insertedId" : ObjectId("5c6ef55a6fd07954a48906a3") } > db.removeFieldCompletlyDemo.insertOne({"StudentName":"Mike", "StudentFavouriteSubject": ["Javascript", "HTML5", "CSS3"]}); { "acknowledged" : true, "insertedId" : ObjectId("5c6ef57b6fd07954a48906a4") } > db.removeFieldCompletlyDemo.insertOne({"StudentName":"Sam", "StudentFavouriteSubject": ["MongoDB", "MySQL", "SQL Server"]}); { "acknowledged" : true, "insertedId" : ObjectId("5c6ef59c6fd07954a48906a5") }Display all documents from a collection ... Read More