You can buy this project and download/modify it how often you want.
/* * Copyright MapStruct Authors. * * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0 */ package org.mapstruct.ap.internal.conversion; import org.mapstruct.ap.internal.model.common.ConversionContext; /** * Handles conversion between a target type {@link StringBuilder} and {@link String}. * */ public class StringBuilderToStringConversion extends SimpleConversion { @Override protected String getToExpression(ConversionContext conversionContext) { return ".toString()"; } @Override protected String getFromExpression(ConversionContext conversionContext) { return "new " + ConversionUtils.stringBuilder( conversionContext ) + "( )"; } }