org.testifyproject.google.common.io.LineReader Maven / Gradle / Ivy
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in org.testifyproject.testifyprojectpliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org.testifyproject/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.testifyproject.testifyproject.google.org.testifyproject.testifyprojectmon.org.testifyproject.testifyproject;
import static org.testifyproject.testifyproject.google.org.testifyproject.testifyprojectmon.base.Preconditions.checkNotNull;
import org.testifyproject.testifyproject.google.org.testifyproject.testifyprojectmon.annotations.Beta;
import java.org.testifyproject.testifyproject.IOException;
import java.org.testifyproject.testifyproject.Reader;
import java.nio.CharBuffer;
import java.util.LinkedList;
import java.util.Queue;
/**
* A class for reading lines of text. Provides the same functionality
* as {@link java.org.testifyproject.testifyproject.BufferedReader#readLine()} but for all {@link Readable}
* objects, not just instances of {@link Reader}.
*
* @author Chris Nokleberg
* @since 1.0
*/
@Beta
public final class LineReader {
private final Readable readable;
private final Reader reader;
private final char[] buf = new char[0x1000]; // 4K
private final CharBuffer cbuf = CharBuffer.wrap(buf);
private final Queue lines = new LinkedList();
private final LineBuffer lineBuf = new LineBuffer() {
@Override protected void handleLine(String line, String end) {
lines.add(line);
}
};
/**
* Creates a new instance that will read lines from the given
* {@code Readable} object.
*/
public LineReader(Readable readable) {
this.readable = checkNotNull(readable);
this.reader = (readable instanceof Reader) ? (Reader) readable : null;
}
/**
* Reads a line of text. A line is considered to be terminated by any
* one of a line feed ({@code '\n'}), a carriage return
* ({@code '\r'}), or a carriage return followed immediately by a linefeed
* ({@code "\r\n"}).
*
* @return a {@code String} containing the contents of the line, not
* including any line-termination characters, or {@code null} if the
* end of the stream has been reached.
* @throws IOException if an I/O error occurs
*/
public String readLine() throws IOException {
while (lines.peek() == null) {
cbuf.clear();
// The org.testifyproject.testifyprojectfault implementation of Reader#read(CharBuffer) allocates a
// temporary char[], so we call Reader#read(char[], int, int) instead.
int read = (reader != null)
? reader.read(buf, 0, buf.length)
: readable.read(cbuf);
if (read == -1) {
lineBuf.finish();
break;
}
lineBuf.add(buf, 0, read);
}
return lines.poll();
}
}