CSV Helper

The CSVHelper class provides comprehensive utilities for working with CSV (Comma-Separated Values) files. It offers methods for reading, writing, and manipulating CSV data with a focus on ease of use and robust error handling.

Basic Operations

Reading CSV Data

// Read all data from a CSV file
List<Map<String, String>> allData = CSVHelper.getCsvData("data/employees.csv");

// Read data by filtering on a specific column
List<Map<String, String>> managers = CSVHelper.getCsvDataByColumn(
    "data/employees.csv", 
    "role", 
    "manager"
);

// Read a specific column
List<String> emails = CSVHelper.readColumn("data/employees.csv", "email");

// Read a specific row
Map<String, String> thirdEmployee = CSVHelper.readRow("data/employees.csv", 2);

// Read a specific cell
String salary = CSVHelper.readCell("data/employees.csv", 5, "salary");

// Get row count
int totalEmployees = CSVHelper.getRowCount("data/employees.csv");

Writing CSV Data

// Create new data
List<Map<String, String>> employeeData = new ArrayList<>();
Map<String, String> employee1 = new HashMap<>();
employee1.put("id", "1001");
employee1.put("name", "John Doe");
employee1.put("email", "john@example.com");
employee1.put("role", "developer");
employeeData.add(employee1);

// Write data to a new or existing CSV file
CSVHelper.setCsvData("data/new_employees.csv", employeeData);

// Append data to an existing CSV file
CSVHelper.appendData("data/employees.csv", newEmployeeData);

// Write a value to a specific cell
CSVHelper.writeCell("data/employees.csv", 3, "salary", "75000");

// Update an entire row
Map<String, String> updatedInfo = new HashMap<>();
updatedInfo.put("email", "john.doe@example.com");
updatedInfo.put("role", "senior developer");
CSVHelper.updateRow("data/employees.csv", 0, updatedInfo);

Data Manipulation

Structure Modifications

// Add a new column
CSVHelper.addNewColumn("data/employees.csv", "department", "Engineering");

// Rename a column
CSVHelper.renameColumn("data/employees.csv", "dept", "department");

// Delete a row
CSVHelper.deleteRow("data/employees.csv", 4);

// Delete a column
CSVHelper.deleteColumn("data/employees.csv", "phone_number");

// Update all values in a column
CSVHelper.updateColumn("data/employees.csv", "status", "active");

// Replace specific values in a column
CSVHelper.replaceColumnData(
    "data/employees.csv", 
    "department", 
    "Engineering", 
    "Software Engineering"
);

Filtering and Sorting

// Filter data based on multiple conditions
Map<String, String> filters = new HashMap<>();
filters.put("department", "Sales");
filters.put("location", "New York");
List<Map<String, String>> salesNY = CSVHelper.filterData(
    "data/employees.csv", 
    filters
);

// Sort data by a column
List<Map<String, String>> sortedBySalary = CSVHelper.sortData(
    "data/employees.csv", 
    "salary", 
    true // ascending order
);

// Find duplicate entries in a column
List<String> duplicateEmails = CSVHelper.findDuplicateEntries(
    "data/employees.csv", 
    "email"
);

File Operations

// Check if a CSV file exists
boolean exists = CSVHelper.doesFileExist("data/employees.csv");

// Validate if a CSV file has the expected columns
List<String> requiredColumns = Arrays.asList("id", "name", "email", "role");
boolean isValid = CSVHelper.validateFileStructure(
    "data/employees.csv", 
    requiredColumns
);

// Merge two CSV files
CSVHelper.mergeCsvFiles(
    "data/team1.csv", 
    "data/team2.csv", 
    "data/all_teams.csv"
);

// Merge multiple CSV files
List<String> files = Arrays.asList(
    "data/team1.csv", 
    "data/team2.csv", 
    "data/team3.csv"
);
CSVHelper.mergeCsvFiles("data/all_teams.csv", files);

// Export CSV data to a list of lists (for custom processing)
List<List<String>> rawData = CSVHelper.exportToList("data/employees.csv");

Error Handling

The CSVHelper class incorporates robust error handling and logging through the Ellithium reporting system. All operations log their status, making it easy to trace CSV operations during test execution.

// All methods include error logging:
try {
    List<Map<String, String>> data = CSVHelper.getCsvData("data/missing.csv");
    // If file is missing, logs: "CSV file not found: data/missing.csv"
} catch (Exception e) {
    // Additional exception handling if needed
}

Working with Large Files

The CSVHelper is designed to efficiently handle large CSV files by using streaming APIs where appropriate. This ensures memory efficiency when working with large datasets.

Basic Operations​

Reading CSV Data​

Writing CSV Data​

Data Manipulation​

Structure Modifications​

Filtering and Sorting​

File Operations​

Error Handling​

Working with Large Files​