Introduction to the technical principles of Java CVS Reader and Writer framework
The Java CVS Reader and Writer framework are the Java frameworks for reading and writing to the CVS (comma separation value) file.The CVS file is a common text file format, where the data is separated in a comma and each row represents a data record.
Technical principle:
1. Read CSV file:
-W read the content of the CSV file with the input stream of Java.
-The data of each line of data is divided through the comma, and the Java's Split method can be split into fields per line of data.
-Ad the segmentation field data with appropriate data structures (such as arrays, lists, etc.).
-Ad the fields of Java to iterate in each line and do the necessary treatment.
Below is an example of Java code reading CSV files:
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class CSVReader {
public static void main(String[] args) {
String csvFile = "path/to/your/file.csv";
String line;
String cvsSplitBy = ",";
try (BufferedReader br = new BufferedReader(new FileReader(csvFile))) {
while ((line = br.readLine()) != null) {
String[] fields = line.split(cvsSplitBy);
// Make necessary treatment of each field
for (String field : fields) {
System.out.println(field);
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
2. Write into CSV file:
-We the content of the CSV file with the output stream of Java.
-Colate the string of CVS rows, separate the field with a comma, and add a change symbol at the end of the line.
-Chiminate all rows into files with appropriate cycles.
Below is an example of Java code written to CVS files:
import java.io.FileWriter;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
public class CSVWriter {
public static void main(String[] args) {
String csvFile = "path/to/your/file.csv";
try (FileWriter writer = new FileWriter(csvFile)) {
List<String> row1 = Arrays.asList("Data1", "Data2", "Data3");
List<String> row2 = Arrays.asList("Data4", "Data5", "Data6");
// Write the first line
writer.write(String.join(",", row1));
writer.write("
");
// Write into the second line
writer.write(String.join(",", row2));
writer.write("
");
System.out.println("CSV file written successfully.");
} catch (IOException e) {
e.printStackTrace();
}
}
}
Summarize:
The Java CVS Reader and Writer framework make the reading and writing CSV files simple and convenient by using the input flow and output stream of Java and the proper string processing method.Reading CVS files can be split into fields per line of data, and writing CSV files can separate the field from a comma and a change line.The function provided by this framework is an important tool for processing and operation of CSV files.
