java.lang.OutOfMemoryError: Java-Heap-Speicherplatz beim Download riesige Datei

Question

Ich versuche über 100 MB Video MP4-Datei mit dem unten genannten Code herunterladen. Aber ich bekomme "java.lang.OutOfMemoryError: Java Heap Space" beim Herunterladen.

Verwenden von jdk1.7 & Feder MVC.

Ich habe unter SO Links verwiesen, aber keine funktioniert für mich.

how to download large files without memory issues in java

java.lang.OutOfMemoryError: Java heap space while downloading a large file from an URL

mir bitte helfen dieses Problem zu beheben.

OutputStream outStream = null; 
FileInputStream inputStream = null; 
try { 
    ServletContext context = request.getSession().getServletContext();  
    String fileName = Integer.toString(fileId);  
    filePath = fileName+".mp4"; 

    File downloadFile = new File(filePath); 
    inputStream = new FileInputStream(new File(filePath)); 
    // get MIME type of the file 
    String mimeType = context.getMimeType(filePath); 
    if (mimeType == null) { 
     mimeType = "application/octet-stream"; 
    } 
    response.setContentType(mimeType); 
    response.setContentLength((int) downloadFile.length()); 
    String headerKey = "Content-Disposition"; 
    String headerValue = String.format("attachment; filename=\"%s\"",downloadFile.getName()); 
    response.setHeader(headerKey, headerValue); 
    outStream = response.getOutputStream(); 
    byte[] buffer = new byte[1024]; 
    int bytesRead = 0, bytesBuffered = 0; 
    while((bytesRead = inputStream.read(buffer)) > -1) { 
     outStream.write(buffer, 0, bytesRead); 
     bytesBuffered += bytesRead; 
     if (bytesBuffered > 1024 * 1024) { //flush after 1MB 
      bytesBuffered = 0; 
      outStream.flush(); 
     } 
    } 
} catch(Exception e) { 
    e.printStackTrace(); 
} finally { 
    if (inputStream != null) { 
     inputStream.close(); 
    } 
    if (outStream != null) { 
     outStream.flush(); 
     outStream.close(); 
    } 
} 

Answer 1

Sie müssen HttpServletResponse.flushBuffer() nennen, nicht nur OutputStream.flush(), und ziemlich häufig mehr.

Answer 2

Ich habe versucht, unter Code mit 500 MB-Datei und aus Speicherfehler nicht

OutputStream outStream = response.getOutputStream(); 

String mimeType = "application/zip"; 
String headerKey = "Content-Disposition"; 
String headerValue = String.format("attachment; filename=\"%s\"", 
      "abc.zip"); 
response.setHeader(headerKey, headerValue); 
response.setContentType(mimeType); 
response.setStatus(HttpServletResponse.SC_OK); 

File downloadFile = new File("file path"); 
InputStream inputStream = new FileInputStream(downloadFile); 

int n = 0; 
byte[] buf = new byte[1024]; 

while ((n = inputStream.read(buf)) != -1) { 
     outStream.write(buf, 0, n); 
} 

inputStream.close(); 
outStream.flush(); 
outStream.close(); 

und JVM-Einstellungen sind erhalten:

-XX:PermSize=256m 
-XX:MaxPermSize=512m 
-Xms1024m 
-Xmx2048m 
-Dosgi.requiredJavaVersion=1.8 
-XX:+UseG1GC 
-XX:+UseStringDeduplication