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Articles by karthikeya Boyini
Page 106 of 143
How to get the Checksum of a Byte Array in Java?
Create a Byte Array for which you want the Checksum −byte[] arr = "This is it!".getBytes();Now, create a Checksum object −Checksum checksum = new Adler32(); checksum.update(arr, 0, arr.length);The update() above updates the current checksum with the specified array of bytes.Now, get the checksum with getValue() method, which gives the current checksum value.Example Live Demoimport java.util.zip.Adler32; import java.util.zip.Checksum; public class Demo { public static void main(String[] argv) throws Exception { byte[] arr = "This is it!".getBytes(); Checksum checksum = new Adler32(); checksum.update(arr, 0, arr.length); long res = checksum.getValue(); ...
Read MoreHow do you select from MySQL where last value in a string = x?
You can use LIKE operator with wildcards to select the records where last value in a string = x, for example ‘10’, ‘15’, etc.Let us first create a table −mysql> create table DemoTable ( ClientId varchar(20) ); Query OK, 0 rows affected (0.68 sec)Insert records in the table using insert command −mysql> insert into DemoTable values('CLI-101'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('CLI-110'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('CLI-201'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('CLI-210'); Query OK, 1 row affected (0.13 sec) ...
Read MoreCharBuffer put() method in Java
The required value can be written at the current position of the buffer and then the current position is incremented using the method put() in the class java.nio.CharBuffer. This method requires a single parameter i.e. the value to be written in the buffer and it returns the buffer in which the value is inserted.A program that demonstrates this is given as follows −Example Live Demoimport java.nio.*; import java.util.*; public class Demo { public static void main(String[] args) { int n = 5; try { CharBuffer buffer = CharBuffer.allocate(5); ...
Read MoreCheck the frequency of an element in Java with Collections.frequency
Create a List in Java −List< String >list = Arrays.asList("P", "Q", "R", "P", "T", "P", "U", "V", "W", "X", "W" );Now, let’s say you want to get the frequency of element P. For that, use the Collections.frequency() method −Collections.frequency(list, "P");A shown above, we can find the occurrence of any letter as well −Collections.frequency(list, "T");Example Live Demoimport java.util.Arrays; import java.util.Collections; import java.util.List; public class Demo { public static void main(String[] args) { Listlist = Arrays.asList("P", "Q", "R", "P", "T", "P", "U", "V", "W", "X", "W" ); int checkOccurrence = Collections.frequency(list, "P"); System.out.println("Occurrence ...
Read MoreDo Double Equal Sign exist in MySQL?
There is no double equal sign concept. It can be used to compare two values. If you use double equal sign(==) in MySQL, you will get an error message.Let us verify the concept is true or not. Declare a variable −mysql> set @Number=10; Query OK, 0 rows affected (0.00 sec)Now, compare the above variable value with 10. If both the values are same then the result will be 1 otherwise 0.Using double equal sign −mysql> select 10==@Number;This will produce the following output i.e. an error −ERROR 1064 (42000): You have an error in your SQL syntax; check the manual ...
Read MoreGet the Current Working Directory in Java
The method java.lang.System.getProperty() is used to obtain the system property. This system property is specified by the key which is the parameter for the method. To obtain the current working directory, the key used is user.dir.A program that demonstrates this is given as follows −Example Live Demopublic class Demo { public static void main(String[] argv) throws Exception { String currentDirectory = System.getProperty("user.dir"); System.out.println("The current working directory is " + currentDirectory); } }The output of the above program is as follows −OutputThe current working directory is c:\JavaProgramNow let us understand the above program.The current ...
Read MoreCharBuffer hasArray() method in Java
It can be checked if a buffer has the backing of an accessible char array by using the method hasArray() in the class java.nio.CharBuffer. This method returns true if the buffer has the backing of an accessible int array and false otherwise.A program that demonstrates this is given as follows −Example Live Demoimport java.nio.*; import java.util.*; public class Demo { public static void main(String[] args) { int n = 5; try { CharBuffer buffer = CharBuffer.allocate(5); buffer.put('A'); buffer.put('P'); ...
Read MoreChange tinyint default value to 1 in MySQL?
You can use DEFAULT command for this. Following is the syntax −alter table yourTableName change yourColumnName yourColumnName TINYINT(1) DEFAULT 1 NOT NULL;Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, UserName varchar(20), UserAge int, isMarried tinyint(1) ); Query OK, 0 rows affected (0.80 sec)Let us check the description of table −mysql> desc DemoTable;This will produce the following output −+-----------+-------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-----------+-------------+------+-----+---------+----------------+ | Id ...
Read MoreHow to see spaces in data when selecting with MySQL command line client?
Use quote() function for this. The syntax is as follows −select yourColumnName, quote(yourColumnName) from yourTableName;To understand the concept, let us create a table. The query to create a table is as follows −mysql> create table seeSpacesDemo -> ( -> spaceValue varchar(10) -> ); Query OK, 0 rows affected (0.42 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into seeSpacesDemo values(""); Query OK, 1 row affected (0.70 sec) mysql> insert into seeSpacesDemo values(" "); Query OK, 1 row affected (0.45 sec) mysql> insert into seeSpacesDemo values(" "); Query OK, 1 ...
Read MoreFinding only strings beginning with a number using MySQL Regex?
To find strings beginning with a number, use Regular Expressions. Let us first create a table −mysql> create table DemoTable ( Id varchar(200) ); Query OK, 0 rows affected (0.59 sec)Insert records in the table using insert command −mysql> insert into DemoTable values('123User'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values('_$123User'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values('User123456'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('0000User'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values('&^*User'); Query OK, 1 row affected (0.24 sec)Display records ...
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