Java中如何读取大于>40MB的XLSX文件呢?

当我们使用 apache-POI  读取大excel时
      出现 java.lang.OutOfMemoryError: Java heap space

当我使用 -Xmx1024m 为 java 类增加了堆大小
       任然出现相应的错误，那么如何解决呢?

读取大excel的方法

使用POI对excel读取
      即可使用流的方式读取excel 

OPCPackage pkg = OPCPackage.open(file.getPath());
XSSFReader reader = new XSSFReader(pkg);

StylesTable styles = reader.getStylesTable();
ReadOnlySharedStringsTable sharedStrings = new ReadOnlySharedStringsTable(pkg);
ContentHandler handler = new XSSFSheetXMLHandler(styles, sharedStrings, mySheetContentsHandler, true);

XMLReader parser = XMLReaderFactory.createXMLReader();
parser.setContentHandler(handler);
parser.parse(new InputSource(reader.getSheetsData().next()));


String pass ="secret";
File file = new File("data/test1232000.xlsx");
   
try (POIFSFileSystem fs = new POIFSFileSystem(file);
   // wrap in org.apache.poi.poifs.filesystem.DocumentFactoryHelper.getDecryptedStream
   InputStream in = DocumentFactoryHelper.getDecryptedStream(fs, pass);
   OPCPackage pkg = OPCPackage.open(in))
{
    XSSFReader reader = new XSSFReader(pkg);
       
    StylesTable styles = reader.getStylesTable();
    ReadOnlySharedStringsTable sharedStrings = new ReadOnlySharedStringsTable(pkg);
    SheetContentsHandler f = new SheetContentsHandler() {
       // ... your implementation of SheetContentsHandler interface ...
    };
    ContentHandler handler = new XSSFSheetXMLHandler(styles, sharedStrings, f, true);
    XMLReader parser = XMLReaderFactory.createXMLReader();
    parser.setContentHandler(handler);
    parser.parse(new InputSource(reader.getSheetsData().next()));
}