通过iText合并1000 PDF会抛出java.lang.OutOfMemoryError：Java堆空间

Question

我正在尝试通过iText合并1000个PDF文件。我不确定内存泄漏发生在哪里。下面是示例代码。请注意，一旦合并到父文件，我将删除子pdf文件。请指出以下代码中的错误，或者有没有更好的方法在没有内存的情况下做到这一点。此过程通过servlet（不是独立程序）完成

FileInputStream local_fis = null;
BufferedInputStream local_bis = null;
File localFileObj = null;
for(int taIdx=0;taIdx<totalSize;taIdx++){
    frObj = (Form3AReportObject)reportRows.get(taIdx);
    localfilename = companyId + "_" +  frObj.empNumber + ".pdf";

    local_fis = new FileInputStream(localfilename);
    local_bis = new BufferedInputStream(local_fis); 
    pdfReader = new PdfReader(local_bis);

    cb = pdfWriter.getDirectContent(); 
    document.newPage();
    page = pdfWriter.getImportedPage(pdfReader, 1);
    cb.addTemplate(page, 0, 0);
    local_bis.close();
    local_fis.close();

    localFileObj = new File(localfilename);
    localFileObj.delete();
}
document.close();

Answer 1

您可能想要尝试以下操作（为清楚起见，异常处理，文件关闭和删除已删除）：

for(int taIdx = 0; taIdx < totalSize; taIdx++) {
    Form3AReportObject frObj = (Form3AReportObject)reportRows.get(taIdx);

    localfilename = companyId + "_" +  frObj.empNumber + ".pdf";

    FileInputStream local_fis = new FileInputStream(localfilename);

    pdfWriter.freeReader(new PdfReader(local_fis));

    pdfWriter.flush();
}

pdfWriter.close();