得到java.lang.OutOfMemoryError：Java堆空間創建一個使用PDFRender API

Question

我對項目工作從pdfFile圖像（縮略圖/圖片），我需要從PdfFile創造PDFImags，對於我使用PDFRendere API時。我的程序運行成功時，PDF文件大小很小，如104 kb，180 kb，421 kb等，但我得到「異常在線程」Image Fetcher 0「* java.lang.OutOfMemoryError：Java堆空間 」 *當PDF文件大小大約或多於12 MB，13 MB，20 MB。 我檢查它在Windows XP，WINDOWS2003服務器，並在Linux操作系統和並增加Java堆的大小約爲1024萬桶，但我仍然得到java.lang.OutOfMemoryError：Java堆空間。 我的代碼

try { 

     pdfFileName = pdfFileName.trim(); 
     if (pdfFileName != null || !(pdfFileName.equals(""))) { 
      lastIndexx = pdfFileName.lastIndexOf('.'); 

      if (lastIndexx < 0) // if extension not present, concatenate the extension 
      { 
       filePath = pdfPath+ pdfFileName + ".pdf"; 

      } else { 
       filePath = pdfPath+ pdfFileName; 
       pdfFileName = pdfFileName.substring(0, lastIndexx); 
      } 
      System.out.println("Pdf system's redefine physical path, where pdfFile are stored, from PdfController.java : " +filePath); 
      file = new File(filePath); 
      raf = new RandomAccessFile(file, "r"); 
      channel = raf.getChannel(); 
      byteBuf = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size()); 
      System.out.println("PdfFile Name before Trim() :" + pdfFileName + ":"); 
      // get a pdf file when pdf is password protected. 
      byte[] bytePassword = pdfFileName.trim()).getBytes();    
      pdfPassword = new PDFPassword(bytePassword); 
      pdffile = new PDFFile(byteBuf, pdfPassword); 

      // draw the image of particular page 
      dpage = pdffile.getPage(pageNo);    

      //get the width and height for the doc at the default zoom 
      rect = new Rectangle(0, 0, (int) dpage.getBBox().getWidth(), (int) dpage.getBBox().getHeight()); 
      //Rectangle rect = new Rectangle(0,0, 200, 300); 

      //BufferedImage bufferedImage = new BufferedImage(rect.width, rect.height, BufferedImage.TYPE_INT_RGB); 
      bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);     
      //generate the image 
      img = dpage.getImage(
        //rect.width, rect.height, //width & height 
        width, height,     // hardcoded in jsp 
        rect, // clip rect 
        null, // null for the ImageObserver 
        true, // fill background with white 
        true // block until drawing is done 
        );     
      bufImageGraphics = bufferedImage.createGraphics();     
      bufImageGraphics.drawImage(img, 0, 0, null); 
      ImageIO.write(bufferedImage, "jpg", new File(directoryName + "//" + pdfFileName + "_" + pageNo + ".jpg")); 
        succ = true; 

    } /*catch (OutOfMemoryError ex) { 
     System.out.println("From showPdfMetaData.jsp, OutOfMemoryError, Message : " + ex.getMessage()); 
     System.out.println("From showPdfMetaData.jsp, OutOfMemoryError, Message : " + ex.getCause()); 
     //errorType = "Jvm throw OutOfMemoryError"; 
    }*/catch (MethodNotFoundException ex) { 
     System.out.println("From pdfToImage(), MethodNotFoundException, Message : " + ex.getMessage()); 
     System.out.println("From pdfToImage(), MethodNotFoundException, Message : " + ex.getCause()); 
     System.out.println("pdfFileName, from pdfToImage(), MethodNotFoundException: " + pdfFileName); 
     succ = false; 
    } catch (StringIndexOutOfBoundsException e) { 
     System.out.println("from pdfToImage(), StringIndexOutOfBoundsException !!!"); 
     System.out.println("pdfFileName, from pdfToImage(), StringIndexOutOfBoundsException: " + pdfFileName); 
     e.printStackTrace(); 
     succ = false; 
    } catch (FileNotFoundException e) { 
     System.out.println("from pdfToImage(), FileNotFoundException !!!"); 
     System.out.println("pdfFileName, from pdfToImage(), FileNotFoundException: " + pdfFileName); 
     e.printStackTrace(); 
     succ = false; 
    } catch (IOException e) { 
     System.out.println("from pdfToImage(), IOException !!!"); 
     System.out.println("pdfFileName, from pdfToImage(), IOException: " + pdfFileName); 
     e.printStackTrace(); 
     succ = false; 
    } catch (NullPointerException e) { 
     System.out.println("from pdfToImage(), NullPointerException !!!"); 
     System.out.println("pdfFileName, from pdfToImage(), NullPointerException: " + pdfFileName); 
     e.printStackTrace(); 
     succ = false; 
    } catch (Exception e) { 
     System.out.println("from pdfToImage(), General Exception !!!"); 
     System.out.println("pdfFileName, from pdfToImage(), Exception: " + pdfFileName); 
     e.printStackTrace(); 
     succ = false; 
    } finally { 
     if (raf != null) {     
      byteBuf.clear(); 
      channel.close(); 
      raf.close(); 
     } 
     if(bufferedImage !=null){ 
      bufferedImage.flush(); 
      //bufImageGraphics.finalize(); 
     } 
     if(bufImageGraphics !=null){ 
      bufImageGraphics.dispose(); 
     } 
     if(pdfPassword !=null){ 
      pdfPassword = null;    
     }    
     if(dpage !=null){ 
      dpage = null; 
     } 
     if(rect !=null){ 
      rect = null; 
     }if(img !=null){ 
      img.flush(); 
      img = null; 
     }if(dmsMgmt !=null){ 
      dmsMgmt = null; 
     } 
    } 
    return succ; 
} 

當調試程序在它

img = dpage.getImage(
        //rect.width, rect.height, //width & height 
        width, height, 
        rect, // clip rect 
        null, // null for the ImageObserver 
        true, // fill background with white 
        true // block until drawing is done 
        ); 

我打電話從JSP此方法拋出內存不足的錯誤。所以請引導我任何可能的建議。 在此先感謝，我對任何錯誤的原因，因爲它我的第一個問題在這裏對不起...我會盡量不重複，如果要問qustion錯誤的方式

Answer 1

至少有2個可能的原因java.lang.OutOfMemoryError： Java堆空間。

1. 你的應用程序只需要你提供的更多的內存。您可以嘗試使用-Xmx參數爲java增加內存分配。例如。嘗試將-Xmx512m添加到您的java命令行。
2. 您的應用程序或一個你使用leaks memory庫。然後，您需要嘗試使用衆多工具中的一種來找出並修復泄漏的原因。您可以推薦​​，該領域的新玩家。