Purecsv framework tutorial: use the Java class library for CSV file read and write operation
Purecsv framework tutorial: use the Java class library for CSV file read and write operation
CSV (comma separation value) is a commonly used text format for storing table data.In Java, we can use the PureCSV framework to process the read and write operation of the CSV file.This tutorial will introduce how to read and write CSV files with the PurecsV framework, and provide some Java code examples.
1. Import the Purecsv library
First, we need to import the PureCSV library in the project.You can add the following dependencies to Maven or Gradle configuration files:
Maven:
<dependency>
<groupId>com.googlecode.jcsv</groupId>
<artifactId>purecsv</artifactId>
<version>2.0.3</version>
</dependency>
Gradle:
implementation 'com.googlecode.jcsv:purecsv:2.0.3'
2. Read the CSV file
To read the CSV file, you first need to create a model class to represent each line of data in the CSV file.For example, if the CSV file contains names and age columns, we can create a class called Person:
public class Person {
private String name;
private int age;
// getters and setters
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
Then, we can use the CSVBeanreader class in the Purecsv library to read the data in the CSV file, as shown below:
CsvBeanReader<Person> csvBeanReader = new CsvBeanReaderBuilder<Person>(new FileReader("data.csv"))
.strategy(new AnnotationBasedBeanStrategy<Person>())
.build();
List<Person> persons = csvBeanReader.readAll();
csvBeanReader.close();
// Print the read data
for (Person person : persons) {
System.out.println("Name: " + person.getName() + ", Age: " + person.getAge());
}
In the above example, we first created a CSVBeanReader object and specified the CSV file path to be read.Then use the annotation as a field specified by the Person class to the CSV column, and call the Readall () method to read the data of all rows.Finally, use a cycle to print each piece of data.
3. Write into CSV files
To write data into the CSV file, we can use the CSVBeanwriter class in the Purecsv library.Similar to reading, we first need to create a model class and use the commentary specified fields corresponding to the CSV column.Then, use the CSVBEANWRITER class to write the data into the CSV file, as shown below:
List<Person> persons = new ArrayList<>();
Persons.add (New Person ("Zhang San", 25);
Persons.add (New Person ("Li Si", 30);
// Create CSVBeanWriter objects and specify the CSV file path to be written
CsvBeanWriter<Person> csvBeanWriter = new CsvBeanWriterBuilder<Person>(new FileWriter("data.csv"))
.strategy(new AnnotationBasedBeanStrategy<Person>())
.build();
// Write the data into the CSV file
csvBeanWriter.writeAll(persons);
csvBeanWriter.close();
In the above example, we first created a CSVBeanWriter object and specified the CSV file path to be written.Then use the Writeall () method to write the data into the CSV file.Finally, call the CLOSE () method to close the CSVBEANWRITER object.
In summary, the PureCSV framework provides a convenient way to handle the read and write operation of the CSV file.Through simple configuration and using CSVBeanReader and CSVBeanwriter, we can easily read and write CSV files.Hope this tutorial will help you!
