CODEWITHSUNDEEP
java
ulquiorra
ulquiorra

Reputation: 945

OutOfMemoryError: Java heap space error

I am experiencing a memory problem that I do not understand. I have the following case

Case 1

public  byte[] getBytes(InputStream is) throws IOException {

            int len;
            int size = 1024;
            byte[] buf;

              ByteArrayOutputStream bos = new ByteArrayOutputStream();
              buf = new byte[size];
              while ((len = is.read(buf, 0, size)) != -1)
              {
                bos.write(buf, 0, len);
              }
              buf = bos.toByteArray();

            return buf;
          }

Public void dosomething()
{
 //instructions
InputStream is = new ByteArrayInputStream(getBytes(bodyPart.getInputStream()));

}

Work fine without error

but this

Case 2

Public void dosomething()
{
 //instructions
ByteArrayOutputStream bos = new ByteArrayOutputStream();
                    int len;
                    int size = 1024;
                    byte[] bufferFichierEntree = new byte[size];
                     while ((len = bodyPart.getInputStream().read(bufferFichierEntree, 0, size)) != -1)
                     {
                         bos.write(bufferFichierEntree, 0, len);
                     }
InputStream is = new ByteArrayInputStream(bufferFichierEntree);

}

return a java.lang.OutOfMemoryError: Java heap space and a don t know why ? The only difference is that in the first case i use a function unlike the second case

Upvotes: 1

Views: 3594

Answers (3)

Mark Bakker
Mark Bakker

Reputation: 1348

seems like a scoping problem with the getInputStream, in the first example you are using 1 InputStream, in the second one infinity,and reading the first 1000 bytes every time. if you change it to like;

InputStream is = bodyPart.getInputStream(); 
while ((len = is.read(bufferFichierEntree, 0, size)) != -1) {

it should run as expected.

Upvotes: 1

Martijn Courteaux
Martijn Courteaux

Reputation: 68847

The reason for it might be:

When you are using two methods, the ByteArrayOutputStream goes out of scope and can be cleaned up by the Garbage Collector (GC).

Using only one method, you the buffer can't be cleaned up by GC since it is still in the scope, unless you nullify it.

Of course, the other reason might be that you are creating each time a new InputStream inside your loop, since we don't know exactly what bodyPart.getInputStream() does. If this is the case, solve it like this:

InputStream in = bodyPart.getInputStream();
while ((len = in.read(bufferFichierEntree, 0, size)) != -1)
{
    bos.write(bufferFichierEntree, 0, len);
}

Upvotes: 1

Pshemo
Pshemo

Reputation: 124225

In 

while ((len=bodyPart.getInputStream().read(bufferFichierEntree, 0, size)) != -1)

you are creating new InputStream in each loop, so you are reading only first bytes in each loop.

Try to create input stream before while and use it the way you did in your first example.

Upvotes: 4

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