Try to make an OOM while reading file with an extream large buffer.

gistfile1.java

package demo;

import java.io.File;
import java.io.FileInputStream;

/**
 * Run the demo on Linux with 32-bit JVM
 * Add the command line parameters -Xmx1600m -Xms1600m. 
 * 
 * readBigBuffer should fail with OOM.
 * readSmallBuffer should be OK.
 * 
 * @author DigitalSonic
 */
public class ReadFileWithBufferDemo {
    public static void main(String[] args) throws Exception {
        System.out.println("Max mem: " + Runtime.getRuntime().maxMemory());
        System.out.println("Current mem: " + Runtime.getRuntime().totalMemory());
        File f = File.createTempFile("tmp", ".txt").getCanonicalFile();
        f.deleteOnExit();
        readBigBuffer(f);
        readSmallBuffer(f);
    }

    public static void readBigBuffer(File f) throws Exception {
        System.out.println("Read the file with 1GB buffer.");
        FileInputStream fis = new FileInputStream(f);
        byte[] bytes = new byte[1024 * 1024 * 1024]; // 1GB
        try {
            System.out.println(fis.read(bytes));
        } catch (OutOfMemoryError e) {
            System.out.println("FAILED!!! OutOfMemoryError!!!");
            e.printStackTrace();
        } finally {
            fis.close();
        }
    }

    public static void readSmallBuffer(File f) throws Exception {
        System.out.println("Read the file with 10MB buffer.");
        FileInputStream fis = new FileInputStream(f);
        byte[] bytes = new byte[1024 * 1024 * 10]; // 10 MB
        int i = 0;
        try {
            while ((i = fis.read(bytes)) > -1) {
                System.out.print(i + ",");
            }
        } catch (OutOfMemoryError e) {
            System.out.println("FAILED!!! OutOfMemoryError!!!");
            e.printStackTrace();
        } finally {
            fis.close();
        }
    }
}