Super CSV Java 8 Extension framework in the Java class library
Super CSV Java 8 Extension framework in the Java class library
introduce:
Super CSV Java 8 Extension is an open source framework for processing CSV files in the Java class library.It provides a set of powerful functions and flexible options that enable developers to easily read, write and operate CSV files.In this article, we will explore the technical principles of the Super CSV Java 8 EXTENSION framework in the Java class library.
Technical principle:
The core working principle of the Super CSV Java 8 Extension framework is based on the Lambda expression and function interface characteristics of the Java 8.It uses these features to simplify the reading and writing process of CSV files, and provide flexible conversion and verification options.
Reading of CSV files:
In the Super CSV Java 8 Extension framework, the core component of the CSV file is CSVReader.The component is responsible for reading the entire CSV file or some CSV files and converted it to the Java object.Based on the Stream API in Java 8, it reads CSV files through streaming operations and uses SeparatorChar (separators) and quotechar (reference characters) to analyze each line record.
The following is an example, showing how to use the Super CSV Java 8 EXTENSION framework to read the CSV file:
public class CSVReaderExample {
public static void main(String[] args) throws IOException {
ICsvBeanReader beanReader = null;
try {
beanReader = new CsvBeanReader(new FileReader("file.csv"), CsvPreference.STANDARD_PREFERENCE);
final String[] header = beanReader.getHeader(true);
final CellProcessor[] processors = getProcessors();
MyBean bean;
while ((bean = beanReader.read(MyBean.class, header, processors)) != null) {
System.out.println(bean);
}
} finally {
if (beanReader != null) {
beanReader.close();
}
}
}
private static CellProcessor[] getProcessors() {
return new CellProcessor[]{
new notnull (), // check whether the column is empty
New Parseint (), // Convert the string to an integer
New PARSEDATE ("DD/MM/YYYY") // Convert the string to the date
};
}
}
Writing of CSV files:
The Super CSV Java 8 Extension framework also provides the writing function of the CSV file.It uses CSVBEANWRITER to convert the Java object into a CSV format and write it into the file.Similar to CSVReader, CSVBEANWRITER also uses the Stream API of Java 8 to streaming the CSV file writing operation.
The following is an example. How to show how to use the Super CSV Java 8 EXTENSION framework to write to the CSV file:
public class CSVWriterExample {
public static void main(String[] args) throws IOException {
ICsvBeanWriter beanWriter = null;
try {
beanWriter = new CsvBeanWriter(new FileWriter("file.csv"), CsvPreference.STANDARD_PREFERENCE);
final String[] header = { "name", "age", "email" };
// Write the head of the CSV file
beanWriter.writeHeader(header);
// The record of writing into the CSV file
beanWriter.write(new MyBean("John Doe", 30, "john.doe@example.com"), header);
beanWriter.write(new MyBean("Jane Smith", 25, "jane.smith@example.com"), header);
} finally {
if (beanWriter != null) {
beanWriter.close();
}
}
}
}
Summarize:
The Super CSV Java 8 EXTENSION framework uses the Lambda expression and function interface characteristics of the Java 8 to provide a concise and elegant way to read and write the CSV file.By using this framework, developers can easily process CSV files, realize data conversion and verification, and greatly improve development efficiency.Whether you have the need to deal with CSV files, this framework is worth trying.
