Suppose you have a comma-separated list of String e.g. "Samsung, Apple, Sony, Google, Microsoft, Amazon" and you want to convert it into an ArrayList containing all String elements e.g. Samsung, Apple, Google, etc. How do you do that? Well, Java doesn't provide any such constructor or factory method to create ArrayList from delimited String, but you can use String.split() method and Arrays.asList() method together to create an ArrayList from any delimited String, not just comma separated one.
How to Show Open Save File Dialog in Java Swing Application? JFileChooser Example
Hello guys, if you worked in Java GUI-based application then you may know that Swing provides class javax.swing.JFileChooser can be used to present a dialog for the user to choose a location and type a file name to be saved, using the showSaveDialog() method. Syntax of this method is as follows:
public int showSaveDialog(Component parent)
where the parent is the parent component of the dialog, such as a JFrame.
float and double data types in Java with Examples
Hello guys, float and double are two of the important data types in Java, but many developers don't pay enough attention to these two data types, resulting in writing poor code with subtle bugs. To be honest, they are not easy to use because of the complexity with floating-point calculation but knowing even simple things like the maximum and minimum limit of float and double data types and how to compare float and double variables can go a long way in eliminating bugs which are not obvious.
Java - Convert String to Short Example
In the last couple of examples, I have taught you how to convert String to Integer, Long, Double, Float, Boolean, and Byte in Java, and today I will show you how to convert String to Short in Java, but before that let's revise what is a short data type in Java. The short is an integral data type similar to the int but it only takes 2 bytes to store data as compared to 4 bytes required by an int variable. Since it takes only 2 bytes or 16 bits to store data, the range of short is also shorter than int. It ranges from -32,768 to 32767 (inclusive) or -2^15 to 2^15 -1. You might be wondering why the upper bound is 255 and the lower bound is -256 but that's because we have included zero in between.
How to Fix Access restriction: The type BASE64Decoder is not accessible due to restriction Error in Eclipse? [Solution]
Hello guys, if you have been using Eclipse for Java development then you might have seen this dreaded "Access restriction: The type BASE64Decoder is not accessible due to restriction Error" before. This error comes when you are trying to encode String into Base64 using BASE64Decoder in Eclipse because the class BASE64Decoder is not part of JDK's public API, it comes from sun.misc package which is non-public. Though this class is present in JDK and JRE and allows you to encode and decode String into base 64, any access to this class from Eclipse flags as an error in Eclipse IDE. If you compile and run the same program from the command line or NetBeans you will not get this error.
How to Fix javax.net.ssl.SSLHandshakeException: unable to find valid certification path to requested target in Java
Hello guys, this is one of the common errors in a client-server application. The big problem in solving this error is not the error but the knowledge of how client-server SSL handshake works. I have blogged about that before and if you have read that you know that in order to connect to any website or server (like LDAP Server) using SSL, you need to have certificates (public keys) to validate the certificates sends by the website you are connecting. If you don't have the root certificate or public key, which is required to validate the certificate presented by the server in your JRE truststore then Java will throw this error.
5 Difference between BufferedReader and Scanner class in Java? Example
Hello guys, welcome to my blog. Today, we'll discuss another interesting Java interview question, BufferedReader vs Scanner. It's not only important from an interview point of view but also to work efficiently with Java. Even though both BufferedReader and Scanner can read a file or user input from the command prompt in Java, there are some significant differences between them. One of the main differences between BufferedReader and Scanner class is that the former class is meant to just read String or text data while the Scanner class is meant to both read and parse text data into Java primitive types like int, short, float, double, and long.
11 Examples of LocalDate, LocalTime, and LocalDateTime in Java 8
Hello guys, if you are wondering how to use LocalDate, LocalTime, and LocalDateTime classes from Java's new Date and Time API then you have come to the right place. Earlier, I have shared best Java 8 courses, books, and Java 8 interview questions and in this article, I Am going to share common examples of LocalDateTime, LocalDate, and LocalTime class in Java. It's been many years since Java SE 8 was released and Java 8 adoption has come a long way. Java programmers around the world have accepted with both ends, many companies have switched their development on Java 8 and several others are migrating to Java 8 platform.
3 Examples to Convert Date to LocalDate in Java 8? Tutorial
One of the great features of Java 8 is the new Date and Time API which is intended to fix existing issues related to mutability and thread-safety with existing java.util.Date class. But given java.util.Date is used very heavily across all the Java applications, you will often end up with a situation where you need to convert java.uti.Date to java.time.LocalDate while working in Java 8. Unfortunately there is no toLocalDate() method in the java.util.Date class. Though, you can easily convert Date to LocalDate if you are familiar with how new and old API classes map to each other.
How to Convert Date to LocalDate in Java 8 - Example Tutorial
Hello guys, if you want to learn how to convert old Date to new LocalDate in Java 8 then you have come to the right place. Earlier, I have shared 10 examples of LocalDate in Java 8, and in this article, I am going to teach you how to convert Date to LocalDate in Java. you may know that JDK 8 introduced the new Date and Time API, which has got a new set of shiny date classes like LocalDate, LocalTime, etc, but you still have a lot of code written against java.util.Date? In order to work with that code, you should know how to convert java.util.Date to java.util.LocalDate in Java.
How to convert String to Date in Java? Example Tutorial
Hello guys, if you are wondering how to convert a String to Date object in Java then you have come to the right place. Data type conversion is one of the most common tasks in programming and every Java programmer must know how to convert one type to another type. There are many times when you will be required to convert a String to LocalDate or java.util.Date object mostly in a different format like dd-MM-yy or yyyy-MM-dd or simply yyyy MM dd. For example, clients pass dates as String to the Server or sometimes we read Date related data from CSV file. Java provides API for parsing String to date using DateFormat class, though Java's Date and Time API is severely criticized, it is also the most used Date and Time format solution.
How to convert Date to LocalDateTime in Java 8 - Example Tutorial
The LocalDateTime class has been introduced in Java 8 to represent both date and time values. It's local, so date and time are always in your local time zone. Since the java.util.Date has been widely used everywhere in many Java applications, you will often find yourself converting java.util.Date to LocalDate, LocalTime, and LocalDateTime classes of the java.time package. Earlier I have shown you how to convert Date to LocalDate and today, I am going to teach you how to convert Date to LocalDateTime in Java 8. The approach is the same. Since the equivalent class of java.util.Date in new Date and Time API in java.time.Instant, we first convert Date to Instance and then create LocalDateTime instance from that Instant using System's default timezone.
10 Examples to DateTimeFormatter in Java 8 to Parse, Format LocalDate and LocalTime
Parsing and formatting dates are other essential topics while working with date and time in Java. Even though the old Date API had the SimpleDateFormat and DateFormat class to support the formatting of date and parsing texts, they were not simple, or should I say there were just simple in writing the wrong code. You might know that SimpleDateFormat was not thread-safe and quite heavy to be used as a local variable. Thankfully, this has been sorted now with a new LocalDateTime class and DateTimeFormatter class, which has several inbuilt formats.
How to Format Date to String in Java 8 [Example Tutorial]
One of the common programming tasks in Java is to change the date format of a given Date or String. For example, you have something like "2017-01-18 20:10:00" and you want to convert it that date into "2017-01-18", or you want to convert from dd-MM-YY to MM-dd-YY or to any other format of your choice and need, but a valid date format as per Java specification. How will you do that? Well, it's not that difficult. It's just a two-step process. In the first step, you need to parse String to create an equivalent date using the current format, and then once you got the date, you need to again convert it back to String using the new format. The same process is repeated in both Java 8 and before, only corresponding API and class changes.
How to Convert java.util.Date to LocalDate in Java 8 - Example Tutorial
Hello guys, once you move to Java 8, you will often find yourself working between old and new Date and Time API, as not all the libraries and systems you interact with will be using Java 8. One of the common tasks which arise from this situation is converting old Date to new LocalDate and that's what you will learn in this tutorial. There seems to be a couple of ways to convert a java.util.Date to java.time.LocalDate in Java 8, but which one is the best way? We'll figure it out in this article, but first, let's explore these different ways to convert a java.util.Date object to LocalDate in Java 8 code.
How to parse String to LocalDate in Java 8 - DateTimeFormatter Example
From Java 8 onward, you are no longer dependent on the buggy and bulky SimpleDateFormat class to parse and format date Strings into real Date objects in Java e.g. java.util.Date. You can use the DateTimeFormatter class from java.time package for all your formatting and parsing need. You are also no longer required to use another buggy class java.util.Date if you are doing fresh development, but if you have to support legacy code then you can also easily convert LocalDate and LocalTime to java.util.Date or java.sql.Date. In this tutorial, we will learn about both parsing String to date in Java and formatting Date into String.
How to Convert String to LocalDateTime in Java 8 - Example Tutorial
Hello guys, today, I will talk about a common problem while working in a Java application, yes you guessed it right, I am talking about String to Date conversion in Java. I had discussed this before (see the Date to String) when Java 8 was not out, but with Java 8, I don't see any reason to use old date and time API, and hence I am writing this post to teach you how to convert String to Date in Java 8 or beyond. Suppose you have a date-time String "2016-03-04: 11:01:20" and you want to convert this into a LocalDateTime object of Java 8 new date and time API, how do you do that? Well, if you have worked previously with String and Date then you know that you can parse String to Date in Java.
How to Calculate Next Date and Year in Java? LocalDate and MonthDay Example Tutorial
Hello guys, if you are wondering how to calculate the next premium date, next birthday, or exact date for the next Christmas holiday in Java then you have come to the right place. Earlier, I have shared 20+ examples of Date and Time in Java, and in this article, I will show you how you can use the LocalDate and MonthDay class from the new Java 8 Date and Time package to calculate the next or previous date in Java. This new API is very well structured and you have classes to represent different Date concepts, for example, you can use LocalDate to represent a Date without time components like the next premium date or employee joining date or birth date.
How to find difference between two dates in Java 8? Example Tutorial
One of the most common programming task while working with date and time objects are calculating the difference between dates and finding a number of days, months, or years between two dates. You can use the Calendar class in Java to get days, months between two dates. The easiest way to calculate the difference between two dates is by calculating milliseconds between them by converting java.util.Date to milliseconds using the getTime() method. The catch is converting those milliseconds into Days, Months and Year is not tricky due to leap years, the different number of days in months, and daylight saving times.
How to get current Day, Month, Year from Date in Java? LocalDate vs java.util.Date Example
In this article, I'll show you how to get the current day, month, year, and dayOfWeek in Java 8 and earlier version like Java 6 and JDK 1.7. Prior to Java 8, you can use the Calendar class to get the various attribute from java.util.Date in Java. The Calendar class provides a get() method which accepts an integer field corresponding to the attribute you want to extract and return the value of the field from the given Date, as shown here. You might be wondering, why not use the getMonth() and getYear() method of java.util.Date itself, well, they are deprecated and can be removed in the future version, hence it is not advised to use them.
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