LaukvikCSV

Continuous Integration:
License: Apache 2.0

An easy to use API for reading, writing, querying and exporting data.

Reading files

The easiest way to read a CSV file is to call the default constructor. This method will try to auto detect separator character and encoding.

CSV csv = new CSV(new File("presidents.csv"));

To read files using a SEMI COLON as separator character

CSV csv = new CSV();
csv.readFile( new File("presidents.csv"), CSV.SEMICOLON );

To read files using a semi colon as PIPE character

CSV csv = new CSV();
csv.readFile( new File("presidents.csv"), CSV.PIPE );

To read files using a semi colon as TAB character

CSV csv = new CSV();
csv.readFile( new File("presidents.csv"), CSV.TAB );

Reading file with very large data sets

try (CsvReader r = new CsvReader( new File("presidents"), Charset.forName(charset)) )) {
    while (r.hasNext()) {
        Row row = r.next();
    }
}
catch (IOException e) {
    e.printStacktrace();
}

Reading POJO

List<Employee> employees = new ArrayList<>();
employees.add( new Employee("Bob",25,false) );
employees.add( new Employee("Jane",24,true) );
employees.add( new Employee("Yay",32,false) );
CSV csv = new CSV();
csv.readJava(employees);

Writing files

csv.write( new File("presidents.csv") );

Export files

To write the contents to a CSV file

csv.writeFile( new File("presidents.csv") );

To write the contents to a XML file

csv.writeXML( new File("presidents.xml") );

To write the contents to a JSON file

csv.writeXML( new File("presidents.json") );

To write the contents to a HTML file

csv.writeXML( new File("presidents.html") );

To write the contents to ResourceBundle(s)

csv.writeXML( new File("presidents.properties") );

Working with columns

Creating a CSV with two columns

CSV csv = new CSV();
csv.addColumn("President");
csv.addColumn("Party");

Reordering columns. The following example moves the column "Party" from index 1 to index 0

csv.getMetaData().moveColumn(1,0);

Removes the first column (President).

csv.getMetaData().removeColumn(0);

Working with rows

Adding a new row with data

CSV csv = new CSV();
StringColumn president = csv.addColumn("President");
StringColumn party = csv.addColumn("Party");

csv.addRow().update(president, "Barack Obama").update(party, "Democratic");

Moving a row up or down

csv.moveRow( 1, 2 );

Swapping two rows

csv.swapRows( 1, 2 );

Removing rows

csv.removeRow( 5 );

Removing rows between range

csv.removeRows( 5, 10 );

Finding the index

csv.indexOf( row );

Inserting row at a specific index

CSV csv = new CSV();
StringColumn president = csv.addStringColumn("President");
csv.addRow(0).update(president, "Barak Obama");

Iterating rows

Iterating all rows

CSV csv = new CSV();
for (int y=0; y<csv.getRowCount(); y++){
    Row row = csv.getRow(y);
}

Using queries

The API supports fluent queries similar to SQL. The first example finds all rows where President is Barack Obama

List<Row> rows = csv.findByQuery().where().column("President").is("Barack Obama").getResultList();

The second example uses sorting for the results

List<Row> rows = csv.findByQuery().orderBy().asc("President").getResultList();

FrequencyDistribution

Builds a FrequencyDistribution for column with index 2;

FrequencyDistribution fd = csv.buildFrequencyDistribution( 2 );

Distinct Values

Set<String> values = csv.buildDistinctValues(1);