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
Object Oriented Programming Articles
Page 572 of 589
Java Program to minus seconds and nanoseconds from Instant
Let us first set an Instant:Instant now = Instant.ofEpochMilli(184142540078l);Let us now minus seconds from Instant:Instant resSeconds = now.minusSeconds(50);Let us now minus nanoseconds from Instant:Instant resNanoSeconds = now.minusNanos(10000);Exampleimport java.time.Instant; public class Demo { public static void main(String[] args) { Instant now = Instant.ofEpochMilli(184142540078l); System.out.println(now); Instant resSeconds = now.minusSeconds(50); System.out.println("After subtracting seconds = "+resSeconds); Instant resNanoSeconds = now.minusNanos(10000); System.out.println("After subtracting nanoseconds = "+resNanoSeconds); } }Output1975-11-02T06:42:20.078Z After subtracting seconds = 1975-11-02T06:41:30.078Z After subtracting nanoseconds = 1975-11-02T06:42:20.077990Z
Read MoreHow to get days, months and years between two Java LocalDate?
Set the two Java dates:LocalDate date1 = LocalDate.of(2019, 3, 25); LocalDate date2 = LocalDate.of(2019, 4, 29);Now, get the difference between two dates with Period class between() method:Period p = Period.between(date1, date2);Now, get the years, month and days:p.getYears() p.getMonths() p.getDays()Exampleimport java.time.LocalDate; import java.time.Period; public class Demo { public static void main(String[] args) { LocalDate date1 = LocalDate.of(2019, 3, 25); LocalDate date2 = LocalDate.of(2019, 4, 29); System.out.println("Date 1 = "+date1); System.out.println("Date 2 = "+date2); Period p = Period.between(date1, date2); System.out.println("Period = "+p); ...
Read MoreHow to check whether the given date represents weekend in Java
At first, display the current date:LocalDate date = LocalDate.now();Now, get the day of week from the above Date (current date):DayOfWeek day = DayOfWeek.of(date.get(ChronoField.DAY_OF_WEEK));On the basis of the above result, use SWITCH to check for the current day. If the day is SATURDAY/SUNDAY, then it’s Weekend.Exampleimport java.time.DayOfWeek; import java.time.temporal.ChronoField; import java.time.LocalDate; public class Demo { public static void main(String[] argv) { LocalDate date = LocalDate.now(); DayOfWeek day = DayOfWeek.of(date.get(ChronoField.DAY_OF_WEEK)); switch (day) { case SATURDAY: System.out.println("Weekend - Saturday"); ...
Read MoreHow to convert Long array list to long array in Java?
Firstly, declare a Long array list and add some elements to it:ArrayList < Long > arrList = new ArrayList < Long > (); arrList.add(100000 L); arrList.add(200000 L); arrList.add(300000 L); arrList.add(400000 L); arrList.add(500000 L);Now, set the same size for the newly created long array:final long[] arr = new long[arrList.size()]; int index = 0;Each and every element of the Long array list is assigned to the long array:for (final Long value : arrList) { arr[index++] = value; }Exampleimport java.util.ArrayList; public class Demo { public static void main(String[] args) { ArrayList
Read MoreJava Program to convert mathematical string to int
To evaluate mathematical string to int, use Nashorn JavaScript in Java i.e. scripting. Nashorn invoke dynamics feature, introduced in Java 7 to improve performance.For scripting, use the ScriptEngineManager class for the engine:ScriptEngineManager scriptEngineManager = new ScriptEngineManager(); ScriptEngine scriptEngine = scriptEngineManager.getEngineByName("nashorn");Now, use put() to set a key/value pair in the state of the ScriptEngine:scriptEngine.put("one", 10); scriptEngine.put("two", 50); scriptEngine.put("three", 40);Now, here is the mathematical string. Use eval to evaluate:String strExp = "(one + two - three) == 20"; Object evalExp = scriptEngine.eval(strExp);Exampleimport javax.script.ScriptEngine; import javax.script.ScriptEngineManager; import javax.script.ScriptException; public class Demo { public static void main(String[] args) { ScriptEngineManager ...
Read MoreJava Program to parse a mathematical expression and operators
At first, we have set the mathematical expressions:String one = "10+15*20-5/5"; String two = "3+5-6"; String three = "9+2*(6-3+7)";To parse mathematical expression, use Nashorn JavaScript in Java i.e. scripting. Nashorn invoke dynamics feature, introduced in Java 7 to improve performance.For scripting, use the ScriptEngineManager class for the engine:ScriptEngineManager scriptEngineManager = new ScriptEngineManager(); ScriptEngine scriptEngine = scriptEngineManager.getEngineByName("Nashorn");Now for JavaScript code from string, use eval i.e. execute the script. Here, we are parsing mathematical expressions set above:Object expResult1 = scriptEngine.eval(one); Object expResult2 = scriptEngine.eval(two); Object expResult3 = scriptEngine.eval(three);Exampleimport javax.script.ScriptEngine; import javax.script.ScriptEngineManager; public class Demo { public static void main(String[] args) throws ...
Read MoreJava Program to adjust LocalDate to next Tuesday with TemporalAdjusters class
At first, set a LocalDate:LocalDate localDate = LocalDate.of(2019, Month.FEBRUARY, 2);Now, adjust the LocalDate to next Tuesday using next() method:LocalDate date = localDate.with(TemporalAdjusters.next(DayOfWeek.TUESDAY));Exampleimport java.time.DayOfWeek; import java.time.LocalDate; import java.time.Month; import java.time.temporal.TemporalAdjusters; public class Demo { public static void main(String[] args) { LocalDate localDate = LocalDate.of(2019, Month.FEBRUARY, 2); System.out.println("Current Date = "+localDate); System.out.println("Current Month = "+localDate.getMonth()); LocalDate date = localDate.with(TemporalAdjusters.firstDayOfMonth()); System.out.println("First day of month = "+date); date = localDate.with(TemporalAdjusters.next(DayOfWeek.TUESDAY)); System.out.println("Next Tuesday date = "+date); } }OutputCurrent Date = 2019-02-02 Current ...
Read MoreJava Program to convert Instant to LocalDateTime
Let’s say you need to convert Instant to LocalDateTime with IST with timezone:Create an Instant:Instant instant = new Date().toInstant();Now, convert Instant to LocalDateTime:LocalDateTime date = LocalDateTime.ofInstant(instant, ZoneId.of(ZoneId.SHORT_IDS.get("IST")));Exampleimport java.time.Instant; import java.time.LocalDateTime; import java.time.ZoneId; import java.util.Date; public class Demo { public static void main(String[] args) { Instant instant = new Date().toInstant(); LocalDateTime date = LocalDateTime.ofInstant(instant, ZoneId.of(ZoneId.SHORT_IDS.get("IST"))); System.out.println("Date (IST) = " + date); date = LocalDateTime.ofInstant(instant, ZoneId.of(ZoneId.SHORT_IDS.get("PST"))); System.out.println("Date (PST) = " + date); date = LocalDateTime.ofInstant(instant, ZoneId.of(ZoneId.SHORT_IDS.get("EST"))); System.out.println("Date (EST) = " ...
Read MoreHow to flush output stream after writing bytes
Let us first crate OutputStream with file input.txt −FileOutputStream fileStream = new FileOutputStream("E:/input.txt"); DataOutputStream dataStream = new DataOutputStream(fileStream);Now, the writeBytes() method writes out the string to the underlying output stream as a sequence of bytes.dataStream.writeBytes("Demo text!");Flush the output stream −dataStream.flush();The following is an example. Here, our file is “E:/input.txt” and at the end we are flushing the output stream −Exampleimport java.io.DataOutputStream; import java.io.FileOutputStream; public class Demo { public static void main(String[] args) throws Exception { FileOutputStream fileStream = new FileOutputStream("E:/input.txt"); DataOutputStream dataStream = new DataOutputStream(fileStream); dataStream.writeBytes("Demo text!"); ...
Read MoreHow to use Iterator to loop through the Map key set?
First, create a HashMap, which is to be iterated −Mapmap = new LinkedHashMap(); map.put("Jack", "0"); map.put("Tim", "1"); map.put("David", "2"); map.put("Tom", "3"); map.put("Kevin", "4");Now, use Iterator to map through keyset −Iterator iterator = map.keySet().iterator();Iterate through all the pairs −while (iterator.hasNext()) { String resKey = (String) iterator.next(); System.out.println("Rank of " + resKey + " is " + map.get(resKey)); }Example Live Demoimport java.util.Iterator; import java.util.LinkedHashMap; import java.util.Map; public class Demo { public static void main(String[] args) { Mapmap = new LinkedHashMap(); map.put("Jack", "0"); map.put("Tim", "1"); map.put("David", "2"); ...
Read More