I basically have a program that filters records from one excel file to another excel file using the apache poi. My program runs fine when it runs using netbeans. However, upon doing a clean and build and double clicking the .jar file inside the dist folder, it runs for very long( too long!) and gives me the following error( that I got by running the program from command prompt ). Is there any work around for it? I have already increase the heap size to be -Xms1500m inside netbeans before cleaning and building. Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: Java heap space at org.apache.xmlbeans.impl.store.Saver$TextSaver.resize(Saver.java:1592) at org.apache.xmlbeans.impl.store.Saver$TextSaver.preEmit(Saver.java:1223) at org.apache.xmlbeans.impl.store.Saver$TextSaver.emit(Saver.java:1144) at org.apache.xmlbeans.impl.store.Saver$TextSaver.emitElement(Saver.java:926) at org.apache.xmlbeans.impl.store.Saver.processElement(Saver.java:456) at org.apache.xmlbeans.impl.store.Saver.process(Saver.java:307) at org.apache.xmlbeans.impl.store.Saver$TextSaver.saveToString(Saver.java:1727) at org.apache.xmlbeans.impl.store.Cursor._xmlText(Cursor.java:546) at org.apache.xmlbeans.impl.store.Cursor.xmlText(Cursor.java:2436) at org.apache.xmlbeans.impl.values.XmlObjectBase.xmlText(XmlObjectBase.java:1455) at org.apache.poi.xssf.model.SharedStringsTable.getKey(SharedStringsTable.java:130) at org.apache.poi.xssf.model.SharedStringsTable.addEntry(SharedStringsTable.java:176) at org.apache.poi.xssf.usermodel.XSSFCell.setCellType(XSSFCell.java:755) at equity.EquityFrame_Updated.copyRowsFromOldToNew(EquityFrame_Updated.java:646) at equity.EquityFrame_Updated.init(EquityFrame_Updated.java:133) at equity.EquityFrame_Updated.createAndShowGUI(EquityFrame_Updated.java:71) at equity.EquityFrame_Updated.<init>(EquityFrame_Updated.java:50) at equity.FileOpener.generateButtonPressed(FileOpener.java:160) at equity.FileOpener.access$100(FileOpener.java:17) at equity.FileOpener$2.actionPerformed(FileOpener.java:61) at javax.swing.AbstractButton.fireActionPerformed(Unknown Source) at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source) at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source) at javax.swing.DefaultButtonModel.setPressed(Unknown Source) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source) at java.awt.Component.processMouseEvent(Unknown Source) at javax.swing.JComponent.processMouseEvent(Unknown Source) at java.awt.Component.processEvent(Unknown Source) at java.awt.Container.processEvent(Unknown Source) at java.awt.Component.dispatchEventImpl(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source)