Analysis and practice of "Simple CSV" framework technical principles in the Java class library
Analysis and practice of "Simple CSV" framework technical principles in the Java class library
Introduction:
CSV (comma separation value) is a common data format that is usually used to exchange data between different applications.The Java class library provides a variety of CSV frameworks, one of which is "Simple CSV".This article will explore the technical principles of the "Simple CSV" framework and provide relevant practical examples and configurations.
Technical principle:
1. Read the CSV file:
-Chn the CSV file with the Java FileRereader class.
-Chibly read every line of files.
-Ad the comma as a separators and split each line into fields.
-Ad each field to a Java object and add the object to the list.
2. Write into CSV file:
-Colon a new CSV file with the Java FileWriter class.
-The list of Java objects.
-The format each field of the object into a CSV format and write each line of the file.
3. Configuration selection:
-You can use the default configuration of the "Simple CSV" framework to read and write the CSV file, or customize the configuration as needed.
-The default configuration can automatically detect the separators of the CSV file, and transfer the righteousness as needed.
-The custom configuration can be used to customize segments, reference characters, changes, etc.
Example:
The following example demonstrates how to read and write the CSV file with the "Simple CSV" framework:
1. Read the CSV file example:
import com.simplecsv.CsvReader;
public class CsvReaderExample {
public static void main(String[] args) {
CsvReader reader = new CsvReader();
// Read the CSV file
List<MyObject> objects;
try {
objects = reader.read("data.csv", MyObject.class);
} catch (IOException e) {
e.printStackTrace();
}
// Turn the list of objects read
for (MyObject obj : objects) {
// Print the field value of each object
System.out.println(obj.getField1());
System.out.println(obj.getField2());
// ...
}
}
}
2. Write into the CSV file example:
import com.simplecsv.CsvWriter;
public class CsvWriterExample {
public static void main(String[] args) {
CsvWriter writer = new CsvWriter();
// Create a list of objects
List<MyObject> objects = new ArrayList<>();
objects.add(new MyObject("value1", "value2"));
objects.add(new MyObject("value3", "value4"));
// Write into CSV files
try {
writer.write("data.csv", objects, MyObject.class);
} catch (IOException e) {
e.printStackTrace();
}
}
}
Code explanation:
-In read the CSV file example, we first created a CSVReader object and called its read method to read the CSV file.The Read method accepts the CSV file path and the type of object to be mapping as the parameter, and returns a list containing the read object.
-In the Writing CSV file example, we first created a CSVWriter object and called its Write method to write the object list into the CSV file.The WRITE method accepts the CSV file path, object list, and object type as the parameter.
Related configuration:
If a custom configuration is required, it can be implemented through the constructor or correlation method of CSVReader and CSVWriter.For example, separators, reference characters, and row symbols can be set.
Summarize:
This article introduces the technical principles of the "Simple CSV" framework in the Java class library, and provides a practical example of reading and writing to the CSV file.By understanding the principle and related configuration of the "Simple CSV" framework, you can easily process CSV data in Java applications.
