From ff68b433b8a126b28facd50f37d5e4ae85c82113 Mon Sep 17 00:00:00 2001 From: Dominik Stadler Date: Tue, 29 Mar 2016 17:27:20 +0000 Subject: [PATCH] Bug 58915: Update javadoc for memory consumption and fix some other javadoc and compiler warnings git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1737024 13f79535-47bb-0310-9956-ffa450edef68 --- .../poi/xssf/streaming/SXSSFWorkbook.java | 51 ++++++++++++------- 1 file changed, 34 insertions(+), 17 deletions(-) diff --git a/src/ooxml/java/org/apache/poi/xssf/streaming/SXSSFWorkbook.java b/src/ooxml/java/org/apache/poi/xssf/streaming/SXSSFWorkbook.java index d5befb615..6757baf21 100644 --- a/src/ooxml/java/org/apache/poi/xssf/streaming/SXSSFWorkbook.java +++ b/src/ooxml/java/org/apache/poi/xssf/streaming/SXSSFWorkbook.java @@ -57,6 +57,19 @@ import org.apache.poi.xssf.usermodel.XSSFWorkbook; /** * Streaming version of XSSFWorkbook implementing the "BigGridDemo" strategy. * + * This allows to write very large files without running out of memory as only + * a configurable portion of the rows are kept in memory at any one time. + * + * You can provide a template workbook which is used as basis for the written + * data. + * + * See https://poi.apache.org/spreadsheet/how-to.html#sxssf for details. + * + * Please note that there are still things that still may consume a large + * amount of memory based on which features you are using, e.g. merged regions, + * comments, ... are still only stored in memory and thus may require a lot of + * memory if used extensively. + * * SXSSFWorkbook defaults to using inline strings instead of a shared strings * table. This is very efficient, since no document content needs to be kept in * memory, but is also known to produce documents that are incompatible with @@ -96,7 +109,7 @@ public class SXSSFWorkbook implements Workbook { private final SharedStringsTable _sharedStringSource; /** - * Construct a new workbook + * Construct a new workbook with default row window size */ public SXSSFWorkbook(){ this(null /*workbook*/); @@ -160,7 +173,7 @@ public class SXSSFWorkbook implements Workbook { * without having a chance to specify any cells. *

* - * @param rowAccessWindowSize + * @param rowAccessWindowSize the number of rows that are kept in memory until flushed out, see above. */ public SXSSFWorkbook(XSSFWorkbook workbook, int rowAccessWindowSize){ this(workbook,rowAccessWindowSize, false); @@ -184,7 +197,7 @@ public class SXSSFWorkbook implements Workbook { * without having a chance to specify any cells. *

* - * @param rowAccessWindowSize + * @param rowAccessWindowSize the number of rows that are kept in memory until flushed out, see above. * @param compressTmpFiles whether to use gzip compression for temporary files */ public SXSSFWorkbook(XSSFWorkbook workbook, int rowAccessWindowSize, boolean compressTmpFiles){ @@ -210,7 +223,7 @@ public class SXSSFWorkbook implements Workbook { *

* * @param workbook the template workbook - * @param rowAccessWindowSize + * @param rowAccessWindowSize the number of rows that are kept in memory until flushed out, see above. * @param compressTmpFiles whether to use gzip compression for temporary files * @param useSharedStringsTable whether to use a shared strings table */ @@ -251,18 +264,22 @@ public class SXSSFWorkbook implements Workbook { * without having a chance to specify any cells. *

* - * @param rowAccessWindowSize + * @param rowAccessWindowSize the number of rows that are kept in memory until flushed out, see above. */ public SXSSFWorkbook(int rowAccessWindowSize){ this(null /*workbook*/, rowAccessWindowSize); } - - public int getRandomAccessWindowSize() - { + + /** + * See the constructors for a more detailed description of the sliding window of rows. + * + * @return The number of rows that are kept in memory at once before flushing them out. + */ + public int getRandomAccessWindowSize() { return _randomAccessWindowSize; } - private void setRandomAccessWindowSize(int rowAccessWindowSize) - { + + private void setRandomAccessWindowSize(int rowAccessWindowSize) { if(rowAccessWindowSize == 0 || rowAccessWindowSize < -1) { throw new IllegalArgumentException("rowAccessWindowSize must be greater than 0 or -1"); } @@ -296,14 +313,12 @@ public class SXSSFWorkbook implements Workbook { XSSFSheet getXSSFSheet(SXSSFSheet sheet) { - XSSFSheet result=_sxFromXHash.get(sheet); - return result; + return _sxFromXHash.get(sheet); } SXSSFSheet getSXSSFSheet(XSSFSheet sheet) { - SXSSFSheet result=_xFromSxHash.get(sheet); - return result; + return _xFromSxHash.get(sheet); } void registerSheetMapping(SXSSFSheet sxSheet,XSSFSheet xSheet) @@ -311,6 +326,7 @@ public class SXSSFWorkbook implements Workbook { _sxFromXHash.put(sxSheet,xSheet); _xFromSxHash.put(xSheet,sxSheet); } + void deregisterSheetMapping(XSSFSheet xSheet) { SXSSFSheet sxSheet=getSXSSFSheet(xSheet); @@ -326,6 +342,7 @@ public class SXSSFWorkbook implements Workbook { _xFromSxHash.remove(xSheet); } + private XSSFSheet getSheetFromZipEntryName(String sheetRef) { for(XSSFSheet sheet : _sxFromXHash.values()) @@ -334,6 +351,7 @@ public class SXSSFWorkbook implements Workbook { } return null; } + private void injectData(File zipfile, OutputStream out) throws IOException { ZipFile zip = ZipHelper.openZipFile(zipfile); @@ -629,7 +647,7 @@ public class SXSSFWorkbook implements Workbook { } SXSSFSheet createAndRegisterSXSSFSheet(XSSFSheet xSheet) { - SXSSFSheet sxSheet=null; + final SXSSFSheet sxSheet; try { sxSheet=new SXSSFSheet(this,xSheet); @@ -704,8 +722,7 @@ public class SXSSFWorkbook implements Workbook { @SuppressWarnings("unchecked") public T next() throws NoSuchElementException { final XSSFSheet xssfSheet = it.next(); - final T sxssfSheet = (T) getSXSSFSheet(xssfSheet); - return sxssfSheet; + return (T) getSXSSFSheet(xssfSheet); } /** * Unexpected behavior may occur if sheets are reordered after iterator