Analysis of the "Simple CSV" framework technical principle in the Java class library
Analysis of the "Simple CSV" framework technical principle in the Java class library
Brief introduction
CSV (COMMA SEPARATED VALUES) is a commonly used file format in a comma -separated file.In order to facilitate Java developers to handle the CSV file, the Java class library provides a framework called Simple CSV.This article will analyze the technical principles of the Simple CSV framework and introduce the corresponding programming code and related configuration.
Simple CSV framework technical principle
The Simple CSV framework provides a set of easy -to -use API for reading and writing to CSV files.The technical principles behind it are as follows:
1. Data reading
Simple CSV first reads CSV files through the CSVReader class.It analyzes each line in the file and splits it into a data field that is separated by a comma.The comma is the default separator, but you can also specify other separators.
2. Data writing
Simple CSV's CSVWRITER class can be used to write data to CSV files.You can write the data into the file in the form of a comma, or you can specify other separators.CSVWriter also provides some auxiliary methods, such as writing file header information and one -time written data table.
3. Class mapping
Simple CSV uses annotations to map the data of the CSV file to the attributes of the Java class.You can use the @CSVBindByname annotation to map the column of the CSV file to the attribute field of the Java class, and you can also use the specified date format of the @CSVDATE annotation.
4. Filter
Simple CSV provides some filters for screening data to be written or read.You can use the @CSVBindByPosition filter to specify the file location you want to read. You can also use the @CSVNUMBER filter to specify the value format.
5. Dreatment of abnormalities
The Simple CSV framework provides an abnormal processing mechanism to process errors that may occur when reading or writing to CSV files.You can make errors by capturing and handling the corresponding abnormalities.
Related programming code and configuration
The following is a sample code read and write to the CSV file with the Simple CSV framework:
import com.opencsv.CSVReader;
import com.opencsv.CSVWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.List;
public class SimpleCSVExample {
public static void main(String[] args) {
try {
// Read the CSV file
CSVReader reader = new CSVReader(new FileReader("data.csv"));
List<String[]> data = reader.readAll();
reader.close();
// Traversing read data
for (String[] row : data) {
for (String field : row) {
System.out.print(field + " ");
}
System.out.println();
}
// Write into CSV files
CSVWriter writer = new CSVWriter(new FileWriter("output.csv"));
String[] record1 = {"John", "Doe", "john@example.com"};
String[] record2 = {"Jane", "Smith", "jane@example.com"};
writer.writeNext(record1);
writer.writeNext(record2);
writer.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
It should be noted that in order to run the above code, you need to introduce the relevant dependencies of the Simple CSV framework first, and correctly configure the file path that may be involved.
Summarize
The Simple CSV framework is a convenient Java library for handling CSV files.By analyzing the technical principles and using the corresponding programming code, we can better understand and use the framework.It is hoped that this article can provide a certain help for readers' understanding of the Simple CSV framework.
