Explore the technical principles of the "Simple CSV" framework in the Java library
Learn about the technical principles of the "Simple CSV" framework in the Java class library
Introduction:
Simple CSV is an open source Java class library that is used to analyze and write the CSV (comma split value) file.It can easily read and operate CSV data, and is widely used in data introduction, export and data cleaning.This article will introduce the technical principles of the Simple CSV framework and related programming code and configuration.
Technical principle:
The technical principles of the Simple CSV framework are mainly based on the following aspects:
1. CSV file structure:
The CSV file consists of lines and columns. Each row represents a record, and columns represent the field of the record.Each column is divided (usually comma) through a specific separator, and at the same time, the quotation marks (such as dual quotation marks) can be used to surround the column data to process fields with separators.The Simple CSV framework can automatically analyze the data based on the structure of the CSV file.
2. Data analysis:
The Simple CSV framework analyzes CSV files by programming by providing corresponding APIs.Developers can read the CSV files with the readNext () method of the CSVReader class and obtain all the field values of the line.At the same time, you can also use the setSeparators () method of the CSVREADER class to specify the customizable partition character.
Below is a sample code for reading CSV files:
try (CSVReader reader = new CSVReader(new FileReader("data.csv"))) {
String[] record;
while ((record = reader.readNext()) != null) {
for (String field : record) {
System.out.print(field + " ");
}
System.out.println();
}
} catch (IOException e) {
e.printStackTrace();
}
3. Data writing:
In addition to data analysis, the Simple CSV framework also provides a CSVWriter class to write data into CSV files.Developers can use the Writnext () method of the CSVWRITER class to write a line of data into the CSV file, and use the setSeparator () method of the CSVWRiter class to set the separators.
Below is a sample code written to the CSV file:
try (CSVWriter writer = new CSVWriter(new FileWriter("data.csv"))) {
String[] record = {"John Doe", "25", "john.doe@example.com"};
writer.writeNext(record);
} catch (IOException e) {
e.printStackTrace();
}
This code writes a line of data into CSV files, and the data field is "John Doe", "25" and "John.doe@example.com".
Related configuration:
The Simple CSV framework also supports some related configurations to meet different needs.For example, you can set whether to ignore the air line, whether to skip the header, and set the pre -processor that sets the column field.Developers can set up the corresponding configuration method.
Below is a sample code that ignores the empty line and skip the head head:
CSVReader reader = new CSVReaderBuilder(new FileReader("data.csv"))
.withskiplines (1) // Skip the first line of head head
.withignoreemptylines (true) // ignore the empty line
.build();
This code creates a CSVReader object, setting the first line of the header and ignoring the empty line.
in conclusion:
The Simple CSV framework is a powerful and easy -to -use Java class library for parsing and writing into CSV files.By understanding the technical principles of the Simple CSV framework, we can better understand its working principles and use it flexibly in practical applications.I hope this article will help you understand the Simple CSV framework.
