我正在从Excel文档中读取数据，该文档每两周更新一次，包含大约50,000行数据，在开始新工作表之前可能会达到120,000行。我正在使用Apache POI来获取数据。我在下面得到了这个例外，但是我认为最重要的一个例外是
引起原因:java.lang.OutOfMemoryError:Java堆空间。我已经在具有更少数据的其他excel工作表上测试了我的代码，并且能够读取数据。
如果您对阅读大型Excel文档有任何方法或建议，请分享。
org.apache.poi.POIXMLException: java.lang.reflect.InvocationTargetException
at org.apache.poi.xssf.usermodel.XSSFFactory.createDocumentPart(XSSFFactory.java:62)
at org.apache.poi.POIXMLDocumentPart.read(POIXMLDocumentPart.java:456)
at org.apache.poi.POIXMLDocumentPart.read(POIXMLDocumentPart.java:461)
at org.apache.poi.POIXMLDocumentPart.read(POIXMLDocumentPart.java:461)
at org.apache.poi.POIXMLDocumentPart.read(POIXMLDocumentPart.java:461)
at org.apache.poi.POIXMLDocument.load(POIXMLDocument.java:162)
at org.apache.poi.xssf.usermodel.XSSFWorkbook.<init>(XSSFWorkbook.java:271)
at excelreader.readExcelFile(excelreader.java:28)
at excelreader.main(excelreader.java:18)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at org.apache.poi.xssf.usermodel.XSSFFactory.createDocumentPart(XSSFFactory.java:60)
... 13 more
Caused by: java.lang.OutOfMemoryError: Java heap space
at org.apache.xmlbeans.impl.store.Cur.createElementXobj(Cur.java:260)
at org.apache.xmlbeans.impl.store.Cur$CurLoadContext.startElement(Cur.java:2995)
at org.apache.xmlbeans.impl.store.Locale$SaxHandler.startElement(Locale.java:3207)
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.reportStartTag(Piccolo.java:1082)
at org.apache.xmlbeans.impl.piccolo.xml.PiccoloLexer.parseAttributesNS(PiccoloLexer.java:1822)
at org.apache.xmlbeans.impl.piccolo.xml.PiccoloLexer.parseOpenTagNS(PiccoloLexer.java:1521)
at org.apache.xmlbeans.impl.piccolo.xml.PiccoloLexer.parseTagNS(PiccoloLexer.java:1362)
at org.apache.xmlbeans.impl.piccolo.xml.PiccoloLexer.yylex(PiccoloLexer.java:4678)
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.yylex(Piccolo.java:1290)
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.yyparse(Piccolo.java:1400)
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.parse(Piccolo.java:714)
at org.apache.xmlbeans.impl.store.Locale$SaxLoader.load(Locale.java:3454)
at org.apache.xmlbeans.impl.store.Locale.parseToXmlObject(Locale.java:1276)
at org.apache.xmlbeans.impl.store.Locale.parseToXmlObject(Locale.java:1263)
at org.apache.xmlbeans.impl.schema.SchemaTypeLoaderBase.parse(SchemaTypeLoaderBase.java:345)
at org.openxmlformats.schemas.spreadsheetml.x2006.main.CTPivotCacheRecords$Factory.parse(Unknown Source)
at org.apache.poi.xssf.usermodel.XSSFPivotCacheRecords.readFrom(XSSFPivotCacheRecords.java:62)
at org.apache.poi.xssf.usermodel.XSSFPivotCacheRecords.<init>(XSSFPivotCacheRecords.java:53)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at org.apache.poi.xssf.usermodel.XSSFFactory.createDocumentPart(XSSFFactory.java:60)
at org.apache.poi.POIXMLDocumentPart.read(POIXMLDocumentPart.java:456)
at org.apache.poi.POIXMLDocumentPart.read(POIXMLDocumentPart.java:461)
at org.apache.poi.POIXMLDocumentPart.read(POIXMLDocumentPart.java:461)
at org.apache.poi.POIXMLDocumentPart.read(POIXMLDocumentPart.java:461)
at org.apache.poi.POIXMLDocument.load(POIXMLDocument.java:162)
at org.apache.poi.xssf.usermodel.XSSFWorkbook.<init>(XSSFWorkbook.java:271)
at excelreader.readExcelFile(excelreader.java:28)
at excelreader.main(excelreader.java:18)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
最佳答案
1.在Java中解决OutOfMemoryError的简便方法是使用JVM选项"-Xmx512M"增加最大堆大小，这将立即解决您的OutOfMemoryError。
Java虚拟机(JVM)以固定的内存上限运行，您可以这样修改:
-Xms<size> - Set initial Java heap size
-Xmx<size> - Set maximum Java heap size
$ java -Xms512m -Xmx1024m JavaApp
2解决Java中OutOfMemoryError的第二种方法相当困难，并且当您没有足够的内存并且即使增加最大堆大小后，您仍然会遇到java.lang.OutOfMemoryError，在这种情况下，您可能想要分析应用程序并寻找任何内存泄漏。
因此，您可以使用一些工具来检查内存泄漏，如果没有它，这将非常困难。一些受欢迎的是:
Jmap是JDK6附带的命令行实用程序，它允许您在文件中进行堆的内存转储。如下所示，它很容易使用:
jmap -dump:格式= b，文件=堆转储6054
Eclipse memory analyzer (MAT)是eclipse基金会提供的用于分析Java堆转储的工具。它有助于查找类加载器泄漏和内存泄漏，并有助于最大程度地减少内存消耗。您可以使用MAT分析承载数百万个对象的堆转储，还可以帮助您提取内存泄漏的嫌疑人。
关于java - Java Apache POI，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/31185815/