iciql/src/com/iciql/util/StatementBuilder.java

/*
 * Copyright 2004-2011 H2 Group.
 * Copyright 2011 James Moger.
 *
 * 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 com.iciql.util;

/**
 * A utility class to build a statement. In addition to the methods supported by
 * StringBuilder, it allows to add a text only in the second iteration. This
 * simplified constructs such as:
 * 
 * <pre>
 * StringBuilder buff = new StringBuilder();
 * for (int i = 0; i &lt; args.length; i++) {
 * 	if (i &gt; 0) {
 * 		buff.append(&quot;, &quot;);
 * 	}
 * 	buff.append(args[i]);
 * }
 * </pre>
 * 
 * to
 * 
 * <pre>
 * StatementBuilder buff = new StatementBuilder();
 * for (String s : args) {
 * 	buff.appendExceptFirst(&quot;, &quot;);
 * 	buff.append(a);
 * }
 * </pre>
 */
public class StatementBuilder {

	private final StringBuilder builder = new StringBuilder();
	private int index;

	/**
	 * Create a new builder.
	 */
	public StatementBuilder() {
		// nothing to do
	}

	/**
	 * Create a new builder.
	 * 
	 * @param string
	 *            the initial string
	 */
	public StatementBuilder(String string) {
		builder.append(string);
	}

	/**
	 * Append a text.
	 * 
	 * @param s
	 *            the text to append
	 * @return itself
	 */
	public StatementBuilder append(String s) {
		builder.append(s);
		return this;
	}

	/**
	 * Append a character.
	 * 
	 * @param c
	 *            the character to append
	 * @return itself
	 */
	public StatementBuilder append(char c) {
		builder.append(c);
		return this;
	}

	/**
	 * Append a number.
	 * 
	 * @param x
	 *            the number to append
	 * @return itself
	 */
	public StatementBuilder append(long x) {
		builder.append(x);
		return this;
	}

	/**
	 * Reset the loop counter.
	 * 
	 * @return itself
	 */
	public StatementBuilder resetCount() {
		index = 0;
		return this;
	}

	/**
	 * Append a text, but only if appendExceptFirst was never called.
	 * 
	 * @param s
	 *            the text to append
	 */
	public void appendOnlyFirst(String s) {
		if (index == 0) {
			builder.append(s);
		}
	}

	/**
	 * Append a text, except when this method is called the first time.
	 * 
	 * @param s
	 *            the text to append
	 */
	public void appendExceptFirst(String s) {
		if (index++ > 0) {
			builder.append(s);
		}
	}

	public void append(StatementBuilder sb) {
		builder.append(sb);
	}

	public void insert(int offset, char c) {
		builder.insert(offset, c);
	}

	public String toString() {
		return builder.toString();
	}

	/**
	 * Get the length.
	 * 
	 * @return the length
	 */
	public int length() {
		return builder.length();
	}
}