A Fast Zero Copy CSV files merger for JVM that uses very minimal memory footprint
CsvMerger merges input CSV files without loading them into memory, using direct file copy
Original line separators CR, LF or CRLF are retained after merge, any additional end of file line separators are removed
Just pass in Seq of input file java.io.Path and output file java.io.Path
import com.bpairan.csv.merge.CsvMerger
import java.nio.file.Paths
val inputFilePaths = Seq(Paths.get("File1.csv"), Paths.get("File2.csv"))
val outputPath = Paths.get("output.csv")
CsvMerger().merge(inputFilePaths, outputPath)By default, CsvMerger allocates buffer size of 256 in the heap, but size of the buffer can be input while constructing CsvMerger
import com.bpairan.csv.merge.CsvMerger
import java.nio.file.Paths
val inputFilePaths = Seq(Paths.get("File1.csv"), Paths.get("File2.csv"))
val outputPath = Paths.get("output.csv")
CsvMerger(128).merge(inputFilePaths, outputPath)To merge files without header just set the flag hasHeader = false
import com.bpairan.csv.merge.CsvMerger
import java.nio.file.Paths
val inputFilePaths = Seq(Paths.get("File1.csv"), Paths.get("File2.csv"))
val outputPath = Paths.get("output.csv")
CsvMerger(hasHeader = false).merge(inputFilePaths, outputPath)Just pass in List of input file java.io.Path and output file java.io.Path
import com.bpairan.csv.merge.javaApi.CsvMerger;
import java.nio.file.Paths;
import java.util.List;
import java.util.ArrayList;
public class Main {
public static void main(String[] args) {
List<Path> inputPaths = new ArrayList<>();
inputPaths.add(Paths.get("File1.csv"));
inputPaths.add(Paths.get("File2.csv"));
Path outputPath = Paths.get("output.csv");
new CsvMerger().merge(inputPaths, outputPath);
// with bufferSize - size allocated to read the input files default is 256
new CsvMerger(512).merge(inputPaths, outputPath);
//if input file has no header then set false, default is true
new CsvMerger(false).merge(inputPaths, outputPath);
// to set both buffer and header
new CsvMerger(512, false).merge(inputPaths, outputPath);
}
}