Java - Swapping Page
<p>I have built a custom hashmap using two arrays. One contains keys another values. Now, I see sometimes JVM can't able to allocate required memory for those arrays and throws exception. Is there any method to solve this using page swapping or any other method ?</p>

<p>Code:</p>

<pre><code>public class Test1{
public static void main(String args[]){


    try {

   int arrays[]  = new int[50000000] ;
for ( int i = 0; i &lt; 50000000 ; i++)
        {
        arrays[i] = i ;
        }

    }

catch(Exception e){
        System.out.println(e) ;
    }
}
}
</code></pre>

<p>Edit:</p>

<pre><code>    public void load() {
        try {
            FileChannel channel2 = new RandomAccessFile(str1, "r").getChannel();
            MappedByteBuffer mbb2 = channel2.map(FileChannel.MapMode.READ_ONLY, 0, channel2.size());
            mbb2.order(ByteOrder.nativeOrder());
            assert mbb2.remaining() == savenum * 8;
            for (int i = 0; i &lt; savenum; i++) {
                long l = mbb2.getLong();
                keys[i] = l;
            }
            channel2.close();

            FileChannel channel3 = new RandomAccessFile(str2, "r").getChannel();
            MappedByteBuffer mbb3 = channel3.map(FileChannel.MapMode.READ_ONLY, 0, channel3.size());
            mbb3.order(ByteOrder.nativeOrder());
            assert mbb3.remaining() == savenum * 4;
            for (int i = 0; i &lt; savenum; i++) {
                int l1 = mbb3.getInt();
                values[i] = l1;
            }
            channel3.close();
        } catch (Exception e) {
            System.out.println(e);
        }
    }

    public void save() {
        try {
            FileChannel channel = new RandomAccessFile(str1, "rw").getChannel();
            MappedByteBuffer mbb = channel.map(FileChannel.MapMode.READ_WRITE, 0, savenum * 8);
            mbb.order(ByteOrder.nativeOrder());

            for (int i = 0; i &lt; savenum; i++) {
                mbb.putLong(keys[i]);
            }
            channel.close();

            FileChannel channel1 = new RandomAccessFile(str2, "rw").getChannel();
            MappedByteBuffer mbb1 = channel1.map(FileChannel.MapMode.READ_WRITE, 0, savenum * 4);
            mbb1.order(ByteOrder.nativeOrder());

            for (int i = 0; i &lt; savenum; i++) {
                mbb1.putInt(values[i]);
            }
            channel1.close();
        } catch (Exception e) {
            System.out.println("IOException : " + e);
        }
    }
</code></pre>
