Commons IO example source code file (StringBuilderWriter.java)

This example Commons IO source code file (StringBuilderWriter.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons IO tags/keywords

io, override, override, serializable, string, stringbuilder, stringbuilder, stringbuilderwriter, stringbuilderwriter, writer, writer

The Commons IO StringBuilderWriter.java source code

/*
 * 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 org.apache.commons.io.output;

import java.io.Serializable;
import java.io.Writer;

/**
 * {@link Writer} implementation that outputs to a {@link StringBuilder}.
 * <p>
 * <strong>NOTE: This implementation, as an alternative to
 * <code>java.io.StringWriter, provides an un-synchronized
 * (i.e. for use in a single thread) implementation for better performance.
 * For safe usage with multiple {@link Thread}s then
 * <code>java.io.StringWriter should be used.
 *
 * @version $Revision: 1003647 $ $Date: 2010-10-01 21:53:59 +0100 (Fri, 01 Oct 2010) $
 * @since Commons IO 2.0
 */
public class StringBuilderWriter extends Writer implements Serializable {

    private final StringBuilder builder;

    /**
     * Construct a new {@link StringBuilder} instance with default capacity.
     */
    public StringBuilderWriter() {
        this.builder = new StringBuilder();
    }

    /**
     * Construct a new {@link StringBuilder} instance with the specified capacity.
     *
     * @param capacity The initial capacity of the underlying {@link StringBuilder}
     */
    public StringBuilderWriter(int capacity) {
        this.builder = new StringBuilder(capacity);
    }

    /**
     * Construct a new instance with the specified {@link StringBuilder}.
     *
     * @param builder The String builder
     */
    public StringBuilderWriter(StringBuilder builder) {
        this.builder = (builder != null ? builder : new StringBuilder());
    }

    /**
     * Append a single character to this Writer.
     *
     * @param value The character to append
     * @return This writer instance
     */
    @Override
    public Writer append(char value) {
        builder.append(value);
        return this;
    }

    /**
     * Append a character sequence to this Writer.
     *
     * @param value The character to append
     * @return This writer instance
     */
    @Override
    public Writer append(CharSequence value) {
        builder.append(value);
        return this;
    }

    /**
     * Append a portion of a character sequence to the {@link StringBuilder}.
     *
     * @param value The character to append
     * @param start The index of the first character
     * @param end The index of the last character + 1
     * @return This writer instance
     */
    @Override
    public Writer append(CharSequence value, int start, int end) {
        builder.append(value, start, end);
        return this;
    }

    /**
     * Closing this writer has no effect. 
     */
    @Override
    public void close() {
    }

    /**
     * Flushing this writer has no effect. 
     */
    @Override
    public void flush() {
    }


    /**
     * Write a String to the {@link StringBuilder}.
     * 
     * @param value The value to write
     */
    @Override
    public void write(String value) {
        if (value != null) {
            builder.append(value);
        }
    }

    /**
     * Write a portion of a character array to the {@link StringBuilder}.
     *
     * @param value The value to write
     * @param offset The index of the first character
     * @param length The number of characters to write
     */
    @Override
    public void write(char[] value, int offset, int length) {
        if (value != null) {
            builder.append(value, offset, length);
        }
    }

    /**
     * Return the underlying builder.
     *
     * @return The underlying builder
     */
    public StringBuilder getBuilder() {
        return builder;
    }

    /**
     * Returns {@link StringBuilder#toString()}.
     *
     * @return The contents of the String builder.
     */
    @Override
    public String toString() {
        return builder.toString();
    }
}