COMMONS CSV (Sandbox) framework technical principle analysis in Java class library
COMMONS CSV (Sandbox) framework technical principle analysis in the Java class library analysis
introduce:
Commons CSV (SANDBOX) is a Java class library for processing the comma -segmental value (CSV) file.It provides the function of reading, writing and analysis of CSV files, making processing CSV files more simple and convenient.This article will introduce the technical principles of the Commons CSV framework and provide the corresponding Java code example.
1. Read the CSV file:
It is very simple to read the CSV file with the Commons CSV framework.We only need to create a CSVPARSER object and associate it with the Reader object of the CSV file, and then get the value of the record by traversing the CSV record.
Reader reader = new FileReader("data.csv");
CSVParser parser = new CSVParser(reader, CSVFormat.DEFAULT);
for (CSVRecord record : parser) {
String value1 = record.get(0);
String value2 = record.get(1);
// Execute the operation of the record value
}
parser.close();
In the above example, we use CSVFormat.default format to define the structure of the CSV file.You can also use other formats, such as CSVFormat.excel or custom format to adapt to different CSV file structures.
2. Write into CSV file:
The Commons CSV framework can also be used to write data to CSV files.We can use the CSVPrinter class to create a CSVPrinter object associated with the WRITER object of the CSV file, and use the WriterCord method to write the data to the CSV file.
Writer writer = new FileWriter("data.csv");
CSVPrinter printer = new CSVPrinter(writer, CSVFormat.DEFAULT);
printer.printRecord("Value1", "Value2");
printer.printRecord("Value3", "Value4");
// Add more records
printer.close();
In the above example, we first use the PRINTRECORD method to write the CSV records into the file.You can add more records as needed and close the CSVPrinter object at the end.
3. Analyze the CSV file:
The Commons CSV framework also provides a flexible method to analyze the CSV file.We can use the method provided by the CSVRecord object to obtain the value of the CSV record and process it as needed.
Reader reader = new FileReader("data.csv");
CSVParser parser = new CSVParser(reader, CSVFormat.DEFAULT);
for (CSVRecord record : parser) {
String value1 = record.get(0);
String value2 = record.get(1);
// Execute the operation of the record value
}
parser.close();
In the above example, we use the CSVPARSER object to analyze the CSV file and use the CSVRecord object to obtain the value of each record.We can then deal with these values as needed.
Summarize:
Commons CSV (SANDBOX) is a powerful and easy -to -use Java class library that can be used to process CSV files.This article introduces the technical principles of the Commons CSV framework and provides the corresponding Java code example.You can use these example code to read, write and analyze CSV files in order to better process CSV data.
