SharedStringBuilder.java

/*
 * Copyright 2009-2014 PrimeTek.
 *
 * 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 org.primefaces.util;

import javax.faces.context.FacesContext;

public class SharedStringBuilder {

    /**
	 * Get a shared {@link StringBuilder} instance.
	 * This is required as e.g. 100 e.g. {@link org.primefaces.expression.SearchExpressionFacade#resolveComponentsForClient} calls would create 
	 * 300 {@link StringBuilder} instances!
	 *
	 * @param context The {@link FacesContext}
	 * @param key The key for the {@link FacesContext} attributes.
	 * @return The shared {@link StringBuilder} instance
	 */
	public static StringBuilder get(FacesContext context, String key) {
		StringBuilder builder = (StringBuilder) context.getAttributes().get(key);

		if (builder == null) {
			builder = new StringBuilder();
			context.getAttributes().put(key, builder);
		}
        else {
			builder.setLength(0);
		}

		return builder;
	}
    
    /**
	 * Get a shared {@link StringBuilder} instance.
	 * This is required as e.g. 100 e.g. {@link org.primefaces.expression.SearchExpressionFacade#resolveComponentsForClient} calls would create 
	 * 300 {@link StringBuilder} instances!
	 *
	 * @param key The key for the {@link FacesContext} attributes.
	 * @return The shared {@link StringBuilder} instance
	 */
	public static StringBuilder get(String key) {
        return get(FacesContext.getCurrentInstance(), key);
	}
}