java.io.FilterWriter Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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;
/**
* Wraps an existing {@link Writer} and performs some transformation on the
* output data while it is being written. Transformations can be anything from a
* simple byte-wise filtering output data to an on-the-fly compression or
* decompression of the underlying writer. Writers that wrap another writer and
* provide some additional functionality on top of it usually inherit from this
* class.
*
* @see FilterReader
*/
public abstract class FilterWriter extends Writer {
/**
* The Writer being filtered.
*/
protected Writer out;
/**
* Constructs a new FilterWriter on the Writer {@code out}. All writes are
* now filtered through this writer.
*
* @param out
* the target Writer to filter writes on.
*/
protected FilterWriter(Writer out) {
super(out);
this.out = out;
}
/**
* Closes this writer. This implementation closes the target writer.
*
* @throws IOException
* if an error occurs attempting to close this writer.
*/
@Override
public void close() throws IOException {
synchronized (lock) {
out.close();
}
}
/**
* Flushes this writer to ensure all pending data is sent out to the target
* writer. This implementation flushes the target writer.
*
* @throws IOException
* if an error occurs attempting to flush this writer.
*/
@Override
public void flush() throws IOException {
synchronized (lock) {
out.flush();
}
}
/**
* Writes {@code count} characters from the char array {@code buffer}
* starting at position {@code offset} to the target writer.
*
* @param buffer
* the buffer to write.
* @param offset
* the index of the first character in {@code buffer} to write.
* @param count
* the number of characters in {@code buffer} to write.
* @throws IOException
* if an error occurs while writing to this writer.
*/
@Override
public void write(char[] buffer, int offset, int count) throws IOException {
synchronized (lock) {
out.write(buffer, offset, count);
}
}
/**
* Writes the specified character {@code oneChar} to the target writer. Only the
* two least significant bytes of the integer {@code oneChar} are written.
*
* @param oneChar
* the char to write to the target writer.
* @throws IOException
* if an error occurs while writing to this writer.
*/
@Override
public void write(int oneChar) throws IOException {
synchronized (lock) {
out.write(oneChar);
}
}
/**
* Writes {@code count} characters from the string {@code str} starting at
* position {@code index} to this writer. This implementation writes
* {@code str} to the target writer.
*
* @param str
* the string to be written.
* @param offset
* the index of the first character in {@code str} to write.
* @param count
* the number of chars in {@code str} to write.
* @throws IOException
* if an error occurs while writing to this writer.
*/
@Override
public void write(String str, int offset, int count) throws IOException {
synchronized (lock) {
out.write(str, offset, count);
}
}
}