The Scanner input in Java should be of primitive data types, such as int, float, double, etc., and string types. This class is used to obtain input from the user during runtime. Java.util is a package in Java that has a class called Scanner.
#Java scanner how to#
Also, you’ll learn in detail about how to import Scanner in Java and about the different Scanner class methods in Java. In this article, you will learn in detail about the input functionality of the Java language using Scanner in Java. The input part is handled by the Scanner class. The output gets printed on the console using () and () functions. Similarly, Java, as a programming language, also has functionalities that make Java programs take input and display the output. A programming language is incomplete without these two basic functionalities.
The easiest way to read a CSV file is to use an external library like OpenCSV.Taking user input and displaying the correct output are two extremely important aspects of any programming language. But we may not get the expected results when reading a more complicated CSV file.
We can easily read data from basic CSV files by using BufferedReader or Scanner. Each line of a CSV file represents a record. Even the quotations are removed and the data is presented in a better format.Ī CSV file is used to store data delimited by a comma(or a semicolon in some cases). As we can see, the comma is considered as a value and not a delimiter by the CSVReader.
#Java scanner code#
Let's use the above code for the CSV file in which we had a cell whose value was a comma. import java.io.File įileReader fr = new FileReader(filePath) It returns an array of strings and we don't need to worry about splitting the line. We will use the readNext() method of CSVReader to read the file line by line. The CSVReader is used as a wrapper around a FileReader. OpenCSV is a CSV file parsing library that can make reading from CSV files a lot easier. Reading CSV Files by Using the OpenCSV Library Just like the BufferedReader, the Scanner class approach cannot be used for complex CSV files. List lineData = Arrays.asList(s.nextLine().split(",")) //splitting lines String filePath = "C:\\Users\\Lenovo\\Desktop\\demo.csv" //file path Then we can store individual records in a list of lists. We will simply read each line of the file and then split it by using the comma as a delimiter. This approach is quite similar to that of BufferedReader. We can also use the Scanner class of java.util package to read a CSV file. We also don't require the quotation marks.Įxclamation "!" Reading CSV Files by Using the Scanner Class We can see that no value is stored for the second row of the file(the comma has been omitted). If we try to read this file, then the following data is stored in the lists. For example, consider a CSV file in which the second column is used to store punctuation marks. Note that we cannot use this approach to read more complex CSV files or files in which the comma itself is a value. List lineData = Arrays.asList(line.split(",")) //splitting lines String file = "C:\\Users\\Lenovo\\Desktop\\demo.csv" //file pathīufferedReader br = new BufferedReader(fr) List > data = new ArrayList() //list of lists to store data
Then we can split the line using the split() method and passing the comma as a delimiter. We will simply read each line of the file by using the readLine() method.
The BufferedReader class of the java.io package can be used to read a basic CSV file. Justin, 101, 9.1Ĭlark, 103, 7.1 Reading CSV Files by Using BufferedReader The contents of the file are shown below. For this tutorial, we will use a simple CSV file that contains just three records. In this tutorial, we will learn how to read a CSV file and copy its content into an array or list. Each row of the file is used to represent a data record. CSV files are used to store information delimited by commas. CSV stands for Comma Separated Values and is a very popular file type.
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