com.google.gwt.emul.java.io.StringReader Maven / Gradle / Ivy
/*
* Copyright 2018 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/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 java.io;
import static javaemul.internal.InternalPreconditions.checkArgument;
/**
* Reads characters from a string.
*/
public class StringReader extends Reader {
private final String text;
private int position;
private int mark;
/**
* Constructs a reader which will read from the given string.
*/
public StringReader(String text) {
this.text = text;
}
@Override
public void close() throws IOException { }
/**
* Reads up to the specified number of characters from the string.
*/
@Override
public int read(char[] buf, int off, int readLength) {
if (position >= text.length()) {
return -1;
}
int length = Math.min(text.length() - position, readLength);
text.getChars(position, position + length, buf, off);
position += length;
return length;
}
@Override
public boolean markSupported() {
return true;
}
@Override
public void mark(int readAheadLimit) throws IOException {
checkArgument(readAheadLimit >= 0);
mark = position;
}
@Override
public void reset() throws IOException {
position = mark;
}
}