当我尝试运行下面的程序时，我得到一个 java.lang.OutOfMemoryError: GC 开销限制超出异常。该程序的主要方法访问'指定目录并遍历所有包含.xlsx的文件。这很好用，因为我在任何其他逻辑之前对其进行了测试。它调用 xlsx 的方法基本上将 xlsx 文件转换为 csv 并将其附加到现有文件中也可以正常工作。但是当我把它放在 for 循环中时，这就是我得到这个异常的时候。我猜它在打开 xlsx 并将其转换为 csv 及其打开第二个的时间之后会发生冲突，也许我必须以某种方式关闭这一行：
File inputFile = new File("C:\\Users\\edennis.AD\\Desktop\\test\\"+nameOfFile);
这是我现在唯一的猜测，当循环的第二次迭代到来时，当这个文件干扰时。我正在使用 Apache POI 库来操作 excel 文件。提前致谢！
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class ExcelMan {
public static void main(String[] args) throws FileNotFoundException {
int i =0;
File dir = new File("C:\\Users\\edennis.AD\\Desktop\\test\\");
for (File child : dir.listFiles()) {
//initializing whether the sheet sent to method is first or not, and //counting iterations for each time the for loop as run
boolean firstSheet = true;
i++;
String nameOfFile = child.getName();
if (nameOfFile.contains(".xlsx")){
System.out.println(nameOfFile);
if (i != 0)
firstSheet = false;
File inputFile = new File("C:\\Users\\edennis.AD\\Desktop\\test\\"+nameOfFile);
// writing excel data to csv
File outputFile = new File("C:\\Users\\edennis.AD\\Desktop\\test\\memb.csv");
xlsx(inputFile, outputFile, firstSheet);
}
// }
}
}
static void xlsx(File inputFile, File outputFile, boolean firstSheet) {
// For storing data into CSV files
StringBuffer data = new StringBuffer();
try {
FileOutputStream fos = new FileOutputStream(outputFile, true);
// Get the workbook object for XLSX file
XSSFWorkbook wBook = new XSSFWorkbook(new FileInputStream(inputFile));
// Get first sheet from the workbook
XSSFSheet sheet = wBook.getSheetAt(7);
Row row;
Cell cell;
// Iterate through each rows from first sheet
java.util.Iterator<Row> rowIterator = sheet.iterator();
while (rowIterator.hasNext()) {
if (firstSheet != true)
rowIterator.next();
row = rowIterator.next();
// For each row, iterate through each columns
java.util.Iterator<Cell> cellIterator = row.cellIterator();
while (cellIterator.hasNext()) {
cell = cellIterator.next();
switch (cell.getCellType()) {
case Cell.CELL_TYPE_BOOLEAN:
data.append(cell.getBooleanCellValue() + "^");
break;
case Cell.CELL_TYPE_NUMERIC:
data.append(cell.getNumericCellValue() + "^");
break;
case Cell.CELL_TYPE_STRING:
data.append(cell.getStringCellValue() + "^");
break;
case Cell.CELL_TYPE_BLANK:
data.append("" + "^");
break;
default:
data.append(cell + "^");
}
}
data.append("\r\n");
}
fos.write(data.toString().getBytes());
fos.close();
} catch (Exception ioe) {
ioe.printStackTrace();
}
}
}
附加信息：
下面是堆栈跟踪
MR.xlsx
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at org.apache.xmlbeans.impl.store.Cur$CurLoadContext.attr(Cur.java:3039)
at org.apache.xmlbeans.impl.store.Cur$CurLoadContext.attr(Cur.java:3060)
at org.apache.xmlbeans.impl.store.Locale$SaxHandler.startElement(Locale.java:3250)
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.reportStartTag(Piccolo.java:1082)
at org.apache.xmlbeans.impl.piccolo.xml.PiccoloLexer.parseAttributesNS(PiccoloLexer.java:1802)
at org.apache.xmlbeans.impl.piccolo.xml.PiccoloLexer.parseOpenTagNS(PiccoloLexer.java:1521)
at org.apache.xmlbeans.impl.piccolo.xml.PiccoloLexer.parseTagNS(PiccoloLexer.java:1362)
at org.apache.xmlbeans.impl.piccolo.xml.PiccoloLexer.parseXMLNS(PiccoloLexer.java:1293)
at org.apache.xmlbeans.impl.piccolo.xml.PiccoloLexer.parseXML(PiccoloLexer.java:1261)
at org.apache.xmlbeans.impl.piccolo.xml.PiccoloLexer.yylex(PiccoloLexer.java:4808)
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.yylex(Piccolo.java:1290)
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.yyparse(Piccolo.java:1400)
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.parse(Piccolo.java:714)
at org.apache.xmlbeans.impl.store.Locale$SaxLoader.load(Locale.java:3439)
at org.apache.xmlbeans.impl.store.Locale.parseToXmlObject(Locale.java:1270)
at org.apache.xmlbeans.impl.store.Locale.parseToXmlObject(Locale.java:1257)
at org.apache.xmlbeans.impl.schema.SchemaTypeLoaderBase.parse(SchemaTypeLoaderBase.java:345)
at org.openxmlformats.schemas.spreadsheetml.x2006.main.WorksheetDocument$Factory.parse(Unknown Source)
at org.apache.poi.xssf.usermodel.XSSFSheet.read(XSSFSheet.java:138)
at org.apache.poi.xssf.usermodel.XSSFSheet.onDocumentRead(XSSFSheet.java:130)
at org.apache.poi.xssf.usermodel.XSSFWorkbook.onDocumentRead(XSSFWorkbook.java:286)
at org.apache.poi.POIXMLDocument.load(POIXMLDocument.java:159)
at org.apache.poi.xssf.usermodel.XSSFWorkbook.<init>(XSSFWorkbook.java:207)
at ExcelMan.xlsx(ExcelMan.java:71)
at ExcelMan.main(ExcelMan.java:47)
excel文件非常大，目录中大约有30个左右，最大的一个大约170 MB，我应该从POI更改这些文件大小吗？