de.invation.code.toval.file.LineBasedFileTransformer Maven / Gradle / Ivy

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TOVAL comprises a set of java classes for common programming issues. It includes utils for arrays, lists, sets and collections for convenient handling and modification, but also support for mathematic definitions concerning logic (clauses + resolution) together with some algorithms for permutations, powersets and resolution. Additionally it contains a number of types for multisets, matrices with object keys and much more.

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package de.invation.code.toval.file;

import java.io.IOException;
import java.nio.charset.Charset;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

import de.invation.code.toval.validate.ParameterException;
import de.invation.code.toval.validate.Validate;


public class LineBasedFileTransformer {
	
	protected Charset inputCharset = Charset.forName("UTF-8");
	protected Charset outputCharset = Charset.forName("UTF-8");

	protected boolean omitFirstLine = false;

	protected FileReader input = null;
	protected FileWriter output = null;
	
	private String fileExtension = null;
	
	private int inputLines = 0;
	private int outputLines = 0;
	
	
	//------- Constructors -------------------------------------------------------------------
	
	public LineBasedFileTransformer(){}
	
	public LineBasedFileTransformer(Charset charset) throws ParameterException{
		this(charset, charset);
	}
	
	public LineBasedFileTransformer(Charset inputCharset, Charset outputCharset) throws ParameterException{
		Validate.notNull(inputCharset);
		Validate.notNull(outputCharset);
		this.inputCharset = inputCharset;
		this.outputCharset = outputCharset;
	}
	
	
	//------- Getters and Setters ------------------------------------------------------------
	
	public String getInputCharset(){
		return inputCharset.toString();
	}
	
	public String getOutputCharset(){
		return inputCharset.toString();
	}
	
	public boolean omitsFirstLine(){
		return omitFirstLine;
	}
	
	public void setOmitFirstLine(boolean omitFirstLine){
		this.omitFirstLine = omitFirstLine;
	}
	
	public String getFileExtension(){
		return fileExtension;
	}
	
	public void setFileExtension(String extension){
		this.fileExtension = extension;
	}
	
	protected String getHeaderLine() {
		return null;
	}
	
	public int getInputLines() {
		return inputLines;
	}

	public int getOutputLines() {
		return outputLines;
	}
	
	//------- Methods for setting up the parser ----------------------------------------------

	protected synchronized void initialize(String fileName) throws IOException, ParameterException {
		Validate.notNull(fileName, "File Name must not be null");
		input = new FileReader(fileName, inputCharset);
		String inputName = input.getFile().getAbsolutePath();
		String outputFileName = inputName.substring(0, inputName.indexOf('.'))+"_output";
		output = new FileWriter(outputFileName, outputCharset);
		if(fileExtension != null){
			output.setFileExtension(getFileExtension());
		}
	}
		
	
	public void parseFile(String fileName) throws IOException, ParameterException{
		initialize(fileName);
		
		String headerLine = getHeaderLine();
		if(headerLine != null)
			output.writeLine(headerLine);
		
		String line = null;
		int lineCount = 0;
		while ((line = input.readLine()) != null) {
			if(lineCount == 0 && omitFirstLine){
				lineCount++;
				continue;
			} else {
				writeOutputLine(line);
				lineCount++;
			}
			if(!continueParsing(lineCount))
				break;
		}
		inputLines = lineCount;
		input.closeFile();
		output.closeFile();
	}

	protected boolean continueParsing(int lineCount){
		return true;
	}
	
	private synchronized void writeOutputLine(String outputLine) throws IOException{
		Set lines = transformLine(outputLine);
		if(lines == null || lines.isEmpty())
			return;
		for(String line: lines){
			output.writeLine(line);
			outputLines++;
		}
		
	}
	
	protected synchronized Set transformLine(String line){
		return new HashSet(Arrays.asList(line));
	}

}