add DeferredGeneration sample

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1887238 13f79535-47bb-0310-9956-ffa450edef68

src/examples/src/org/apache/poi/examples/xssf/streaming/DeferredGeneration.java

@@ -0,0 +1,49 @@
+/* ====================================================================
+   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.poi.examples.xssf.streaming;
+
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.xssf.streaming.DeferredSXSSFSheet;
+import org.apache.poi.xssf.streaming.DeferredSXSSFWorkbook;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+public class DeferredGeneration {
+
+	public static void main(String[] args) throws IOException {
+		try (DeferredSXSSFWorkbook wb = new DeferredSXSSFWorkbook()) {
+			DeferredSXSSFSheet sheet1 = wb.createSheet("new sheet");
+
+			sheet1.setRowGenerator((ssxSheet) -> {
+				for (int i = 0; i < 10; i++) {
+					Row row = ssxSheet.createRow(i);
+					Cell cell = row.createCell(1);
+					cell.setCellValue("value " + i);
+				}
+			});
+
+			try (FileOutputStream fileOut = new FileOutputStream("DeferredGeneration.xlsx")) {
+				wb.write(fileOut);
+			} finally {
+				wb.dispose();
+			}
+		}
+	}
+}