How to Read Contents From Csv File in Java

How to Read CSV File in Coffee

The CSV stands for Comma-Separated Values. It is a simple file format which is used to store tabular data in elementary text form, such as a spreadsheet or database. The files in the CSV format can be imported to and exported from programs (Microsoft Office and Excel) which store data in tables. The CSV file used a delimiter to place and separate different data token in a file. The CSV file format is used when we motion tabular data between programs that natively operate on incompatible formats. There are post-obit means to read CSV file in Java. The default separator of a CSV file is a comma (,).

In that location are post-obit ways to print an array in Java:

• Java Scanner class
• Coffee String.divide() method
• Using OpenCSV API

How to create CSV File

There are 2 ways to create a CSV file:

• Using Microsoft Excel
• Using Notepad

Using Microsoft Excel

Stride 1: Open Microsoft Excel.

Stride 2: Write the following information into the file:

Pace 3: Now, salvage the file. Provide the file name CSVDemo and select CSV (Comma delimited) from the save as type carte du jour. Now, click on the Salve push.

Using Notepad

Stride 1: Open up notepad.

Stride ii: Write some data into file separated by comma (,). For example:

Vivek, Singh, 23, 9999999, Chandigarh

Step 3: Relieve the file with .csv extension.

Nosotros have created the following file.

Java Scanner class

Java Scanner class provide diverse methods past which we can read CSV file. The Scanner class provides a constructor that produces values scanned from the specified file. It breaks data into the token form. It uses a delimiter blueprint which by default matches white space. The resulting tokens then converted into values of dissimilar types using the adjacent() methods.

Example

Output:

Shashank, Mishra, Accountant, 909090090, 45000, Moti Vihar Naveen, Singh, Accountant, 213344455, 12000, Shastri Nagar Mahesh, Nigam, Sr. Manager, 787878878, 30000, Ashok Nagar Manish, Gupta, Manager, 999988765, 20000, Saket Nagar          

Java String.split() method

Java String.split() identifies the delimiter and split the rows into tokens.

Syntax

The method parses a delimiting regular expression. The method returns an array of cord computed by splitting this string around matches of the given regular expression.

Consider the cord:

                "this:is:a:table" Regex Result :         {"this", "is", "a", "table"}

Instance

In the following example, nosotros use BufferedReader class which reads file line by line until the EOF (end of file) character is reached.

Output:

Employee [Get-go Name= Shashank, Last Name= Mishra, Designation= Auditor,  Contact= 909090090, Salary= 45000, Metropolis= Moti Vihar] Employee [Offset Name= Naveen, Terminal Name=Singh, Designation= Auditor,  Contact=213344455, Salary= 12000, Urban center= Shastri Nagar] Employee [First Name= Mahesh, Last Name=Nigam, Designation= Sr. Managing director,  Contact=787878878, Salary= 30000, City= Ashok Nagar] Employee [Commencement Name= Manish, Last Name=Gupta, Designation= Manager,  Contact=999988765, Bacon= 20000, City= Saket Nagar]          

Using OpenCSV API

OpenCSV is a 3rd party API which provide standard libraries to read diverse versions of CSV file. The library provides better control to handle the CSV file. The library can also read TDF (Tab-Delimited File) file format.

Features of OpenCSV

• Whatever number of values per line.
• Ignores commas in quoted elements.
• Handles entries that span multiple lines.

The CSVReader class is used to read a CSV file. The class provides CSVReader grade constructor to parse a CSV file.

Syntax

Parameters

reader: The reader to a CSV source.

separator: It is a delimiter which is used for separating entries.

Steps to read CSV file in eclipse:

Stride 1: Create a course file with the name ReadCSVExample3 and write the following code.

Step 2: Create a lib folder in the project.

Step iii: Download opecsv-3.viii.jar from

https://repo1.maven.org/maven2/com/opencsv/opencsv/3.viii/opencsv-three.8.jar

Step 4: Copy the opencsv-3.eight.jar and paste into the lib folder.

Step 5: At present, run the program.

Example

Output:

Shashank Mishra Auditor 909090090 45000 Moti Vihar Naveen Singh Accountant 213344455 12000 Shastri Nagar Mahesh NigamSr. Director 787878878 30000 Ashok Nagar Manish Gupta Manager 999988765 20000 Saket Nagar          

Reading CSV file with a dissimilar separator

In the post-obit CSV file, we have used semicolon (;) to separate tokens.

Example

Output:

Shashank; Mishra; Auditor; 909090090; 45000; Moti Vihar		 Naveen; Singh; Accountant; 213344455; 12000; Shastri Nagar		 Mahesh; Nigam; Sr. Manager; 787878878; 30000; Ashok Nagar		 Manish; Gupta; Manager; 999988765; 20000; Saket Nagar          

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Source: https://www.javatpoint.com/how-to-read-csv-file-in-java

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