The technical principles of the CSV Validator framework in the Java library analysis
The technical principles of the CSV Validator framework in the Java library analysis
Overview:
CSV (comma division value) is a common file format for storing and exchange form data.CSV Validator is a Java class library that is used to verify and analyze the effectiveness of CSV files.This article will analyze the technical principles of the CSV Validator framework and provide some Java code examples to illustrate its usage.
1. Analysis of CSV file structure:
CSV Validator first analyzes the structure of the CSV file, including the number of rows and columns.It uses a separatist (usually comma) to distinguish different columns, and to mark different rows.CSV Validator reads CSV files using Java's input/output class library and uses a specific encoding format to analyze the content of the file.
The following is a simple example. It demonstrates how to use CSV Validator to read and analyze the CSV file:
import com.opencsv.CSVReader;
public class CSVParser {
public static void main(String[] args) {
try (CSVReader reader = new CSVReader(new FileReader("data.csv"))) {
String[] nextLine;
while ((nextLine = reader.readNext()) != null) {
// Process each line of data
for (String cell : nextLine) {
System.out.print(cell + " ");
}
System.out.println();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
2. Data verification:
CSV Validator also provides some functions to verify whether the data in the CSV file meets the expected rules.For example, it can verify whether the data types of certain columns are correct, whether there are vacant or repeated values, and whether it is within the specified range.
The following is an example that shows how to use CSV Validator to verify the data:
import com.github.tsohr.JSONArray;
import com.github.tsohr.JSONObject;
import com.github.tsohr.Validator;
public class CSVDataValidator {
public static void main(String[] args) {
String jsonRules = "{
" +
" \"rules\": [
" +
" {
" +
" \"column\": \"Name\",
" +
" \"type\": \"string\",
" +
" \"required\": true
" +
" },
" +
" {
" +
" \"column\": \"Age\",
" +
" \"type\": \"integer\",
" +
" \"minValue\": 18,
" +
" \"maxValue\": 100
" +
" }
" +
" ]
" +
"}";
String csvData = "Name,Age
" +
"John,25
" +
"Amy,16";
Validator validator = new Validator(jsonRules);
JSONArray result = validator.validate(csvData);
for (int i = 0; i < result.length(); i++) {
JSONObject validationResult = result.getJSONObject(i);
String columnName = validationResult.getString("column");
boolean isValid = validationResult.getBoolean("valid");
String message = validationResult.has("message") ? validationResult.getString("message") : "";
System.out.println("Column: " + columnName + ", Valid: " + isValid + ", Message: " + message);
}
}
}
3. Error treatment and log records:
CSV Validator also provides the function of error processing and log records.When the CSV file contains verification errors, it returns a JSON object containing the error message in order to further process it.In addition, CSV Validator can also record error information into the log file to track the execution of the program.
in conclusion:
The CSV Validator framework is a powerful tool for verifying and analyzing the CSV file in the Java library.It provides the function of analysis of the structure of the CSV file, and supports data verification, error processing and log records.By using CSV Validator, developers can easily verify and analyze CSV files to improve the accuracy and reliability of data.
The above is the analysis of the technical principles of the CSV Validator framework in the Java library. Through the Java code example provided, it is hoped that readers can better understand its usage and functions.
