Frequently Asked Questions Answers: Commons CSV (SANDBOX) framework
Frequently Asked Questions Answers: Commons CSV (SANDBOX) framework
Commons CSV (Sandbox) is a Java library for reading and writing to CSV files.It provides a simple and easy -to -use method to process CSV data, which can easily convert the CSV file into a Java object. It can also convert the Java object to CSV files.
Here are some common questions and answers about the Commons CSV (SANDBOX) framework:
Q: How to read a CSV file and convert it to Java object?
Answer: You can use the CSVParser of the Commons CSV (SANDBOX) framework to analyze the CSV file, and the CSV records can be converted to the Java object by implementing the custom class of the CSVRecord.The following is an example code:
import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;
import org.apache.commons.csv.CSVRecord;
public class CSVReaderExample {
public static void main(String[] args) {
try {
CSVParser parser = CSVParser.parse(new File("data.csv"), Charset.defaultCharset(), CSVFormat.DEFAULT);
for (CSVRecord record : parser) {
String name = record.get(0);
int age = Integer.parseInt(record.get(1));
double salary = Double.parseDouble(record.get(2));
// Perform follow -up operations, such as creating a Java object or saving to database, etc.
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
This code will read data from a CSV file named "Data.csv" and convert each line into a Java object. You can perform subsequent operations as needed.
Q: How to convert the Java object to CSV file and save it on the disk?
Answer: You can use the CSVPrinter of the Commons CSV (SANDBOX) framework to convert the Java object into a CSV format and write it into the CSV file.The following is an example code:
import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVPrinter;
public class CSVWriterExample {
public static void main(String[] args) {
try {
CSVPrinter printer = new CSVPrinter(new FileWriter("data.csv"), CSVFormat.DEFAULT);
printer.printRecord("John Doe", 25, 5000.0);
printer.printRecord("Jane Smith", 30, 6000.0);
printer.flush();
printer.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
This code will create a CSV file called "Data.CSV" and write the data of the two lines into the file.You can modify this code as needed to adapt to your objects and data.
Q: How to process CSV files containing special characters (such as comma and quotes)?
Answer: The Commons CSV (SANDBOX) framework provides a variety of CSV formats. You can select the appropriate format to process CSV files containing special characters as needed.For example, when the field in the CSV file contains a comma, it can be handled using CSVFormat.tdf (Tab Delimited Format).The following is an example code:
import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;
import org.apache.commons.csv.CSVRecord;
public class CSVSpecialCharactersExample {
public static void main(String[] args) {
try {
CSVParser parser = CSVParser.parse(new File("data.csv"), Charset.defaultCharset(), CSVFormat.TDF);
for (CSVRecord record : parser) {
String name = record.get(0);
int age = Integer.parseInt(record.get(1));
double salary = Double.parseDouble(record.get(2));
// Perform follow -up operations, such as creating a Java object or saving to database, etc.
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
This code will read data from a CSV file called "Data.csv" and convert each line into a Java object.CSVFormat.tdf regards the comma as a field separator, not a special character.
These are some common questions and answers about the Commons CSV (Sandbox) framework.I hope this information can help you better use the Commons CSV (Sandbox) framework.
