package nl.hsac.fitnesse.fixture.util;
import org.apache.commons.lang3.StringUtils;
import java.io.*;
import java.nio.channels.FileChannel;
import java.util.Scanner;
/**
* File utilities.
*/
public final class FileUtil {
private static final int BUFFER_SIZE = 4096;
private static final String FILE_ENCODING = "UTF-8";
private FileUtil() {
// ensure no instance is made.
}
/**
* Reads content of UTF-8 file on classpath to String.
*
* @param filename file to read.
* @return file's content.
* @throws IllegalArgumentException if file could not be found.
* @throws IllegalStateException if file could not be read.
*/
public static String loadFile(String filename) {
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
InputStream is = classLoader.getResourceAsStream(filename);
if (is == null) {
throw new IllegalArgumentException("Unable to locate: " + filename);
}
return streamToString(is, filename);
}
/**
* Copies UTF-8 input stream's content to a string (closes the stream).
*
* @param is input stream (UTF-8) to read.
* @param name description for stream in error messages.
* @return content of stream
* @throws RuntimeException if content could not be read.
*/
public static String streamToString(InputStream inputStream, String fileName) {
return streamToString(inputStream, fileName, null);
}
/**
* Copies first <numberOfLines> or all lines from UTF-8 input stream's content to a
* string and closes the stream.
*
* @param is input stream (UTF-8) to read.
* @param name description for stream in error messages.
* @param numberOfLines number of lines to be read from input stream - if null, all lines are read
* @return content of stream
* @throws RuntimeException if content could not be read.
*/
public static String streamToString(InputStream is, String name, Integer numberOfLines) {
String result = null;
try {
try {
if (numberOfLines == null) {
// read complete file into string
result = new Scanner(is, FILE_ENCODING).useDelimiter("\\A").next();
} else {
// read only given number of lines
Scanner scanner = new Scanner(is, FILE_ENCODING);
int resultNrOfLines = 1;
result = "";
while (scanner.hasNext()) {
result = result + scanner.nextLine() + System.lineSeparator();
if (++resultNrOfLines > numberOfLines) {
break;
}
}
scanner.close();
if (result.isEmpty()) {
result = null;
}
}
} catch (java.util.NoSuchElementException e) {
throw new IllegalStateException("Unable to read: " + name + ". Error: " + e.getMessage(), e);
}
} finally {
try {
is.close();
} catch (IOException e) {
// what the hell?!
throw new RuntimeException("Unable to close: " + name, e);
}
}
return result;
}
/**
* Copies source file to target.
* @param source source file to copy.
* @param target destination to copy to.
* @return target as File.
* @throws IOException when unable to copy.
*/
public static File copyFile(String source, String target) throws IOException {
FileChannel inputChannel = null;
FileChannel outputChannel = null;
try {
inputChannel = new FileInputStream(source).getChannel();
outputChannel = new FileOutputStream(target).getChannel();
outputChannel.transferFrom(inputChannel, 0, inputChannel.size());
} finally {
if (inputChannel != null) {
inputChannel.close();
}
if (outputChannel != null) {
outputChannel.close();
}
}
return new File(target);
}
/**
* Copy the contents of the given InputStream to the given OutputStream.
* Closes both streams when done.
*
* @param in the stream to copy from
* @param out the stream to copy to
* @return the number of bytes copied
* @throws java.io.IOException in case of I/O errors
*/
public static int copy(InputStream in, OutputStream out) throws IOException {
try {
int byteCount = 0;
byte[] buffer = new byte[BUFFER_SIZE];
int bytesRead = -1;
while ((bytesRead = in.read(buffer)) != -1) {
out.write(buffer, 0, bytesRead);
byteCount += bytesRead;
}
out.flush();
return byteCount;
} finally {
try {
in.close();
} catch (IOException ex) {
throw new RuntimeException(ex);
}
try {
out.close();
} catch (IOException ex) {
throw new RuntimeException(ex);
}
}
}
/**
* Writes content to file, in UTF-8 encoding.
*
* @param filename file to create or overwrite.
* @param content content to write.
* @return file reference to file.
*/
public static File writeFile(String filename, String content) {
PrintWriter pw = null;
try {
pw = new PrintWriter(filename, FILE_ENCODING);
pw.write(content);
pw.flush();
} catch (FileNotFoundException e) {
throw new IllegalArgumentException("Unable to write to: " + filename, e);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
} finally {
if (pw != null) {
pw.close();
}
}
return new File(filename);
}
public static File writeFromScanner(String filename, Scanner sc) {
PrintWriter pw = null;
try {
pw = new PrintWriter(filename, FILE_ENCODING);
while (sc.hasNextLine()) {
String next = sc.nextLine();
pw.write(next + System.getProperty("line.separator"));
}
} catch (FileNotFoundException e){
throw new IllegalArgumentException("Unable to write to: " + filename + ".tmp", e);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
} finally {
if(pw != null) {
pw.flush();
pw.close();
}
}
return new File(filename);
}
/**
* Saves byte[] to new file.
*
* @param baseName name for file created (without extension),
* if a file already exists with the supplied name an
* '_index' will be added.
* @param extension extension for file.
* @param content data to store in file.
* @return absolute path of created file.
*/
public static String saveToFile(String baseName, String extension, byte[] content) {
String result;
File output = determineFilename(baseName, extension);
FileOutputStream target = null;
try {
target = new FileOutputStream(output);
target.write(content);
result = output.getAbsolutePath();
} catch (Exception e) {
throw new RuntimeException(e);
} finally {
if (target != null) {
try {
target.close();
} catch (IOException ex) {
// what to to?
}
}
}
return result;
}
private static File determineFilename(String baseName, String extension) {
if (!StringUtils.isEmpty(extension)) {
extension = "." + extension;
}
File output = new File(baseName + extension);
// ensure directory exists
File parent = output.getAbsoluteFile().getParentFile();
if (!parent.exists()) {
if (!parent.mkdirs()) {
throw new IllegalArgumentException(
"Unable to create directory: "
+ parent.getAbsolutePath());
}
}
int i = 0;
// determine first filename not yet in use.
while (output.exists()) {
i++;
String name = String.format("%s_%s%s", baseName, i, extension);
output = new File(name);
}
return output;
}
}