ai.api.util.IOUtils Maven / Gradle / Ivy
package ai.api.util;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.nio.charset.Charset;
/**
* Small subset of IO helping functions
*/
public class IOUtils {
private static final int DEFAULT_BUFFER_SIZE = 4096;
/**
* Write string to byte stream
* @param data Source string
* @param outputStream Output stream
* @param charset Convert string to bytes according to given {@link Charset}
* @throws IOException
*/
public static void writeAll(String data, OutputStream outputStream, Charset charset)
throws IOException
{
if ((data != null) && (data.length() > 0)) {
outputStream.write(data.getBytes(charset));
}
}
/**
* Read all stream byte data into {@link String}
* @param inputStream Source stream
* @param charset Convert bytes to chars according to given {@link Charset}
* @return Empty {@link String} if there was no data in stream
* @throws IOException
*/
public static String readAll(InputStream inputStream, Charset charset) throws IOException {
try (InputStreamReader streamReader = new InputStreamReader(inputStream, charset)) {
return readAll(streamReader);
}
}
/**
* Read all chars into String
* @param streamReader Input stream reader
* @return Empty {@link String} if there was no data in stream
* @throws IOException
*/
public static String readAll(InputStreamReader streamReader) throws IOException {
StringWriter result = new StringWriter();
copy(streamReader, result);
return result.toString();
}
private static long copy(Reader reader, Writer writer) throws IOException {
return copy(reader, writer, new char[DEFAULT_BUFFER_SIZE]);
}
private static long copy(Reader reader, Writer writer, char[] buffer)
throws IOException
{
assert buffer != null;
assert buffer.length > 0;
long result = 0;
int read = reader.read(buffer);
while (read > 0) {
writer.write(buffer, 0, read);
result += read;
read = reader.read(buffer);
}
return result;
}
}