Bug 82804 Jar creation should use less memory
I noticed that the JarWriter will read the entire file it plans to store into memory. An optimization would be to stream the file directly into the JarOutputStream. The only catch is with STORED items which need the CRC32 computed. A penalty could be taken in that case to compute the CRC in a loop and then stream the file.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/jarpackager/JarPackageData.java
}
	/**
	 * Set the packages which should explicitly be unsealed.
	 * The following entry will be added to the manifest file for each package:
	 * Name: <name of the package>
	 * Sealed: false
	 * <p>
	 * This should only be used if the JAR itself is sealed.
	 * </p>
	 * 
	 * @param packagesToUnseal an array of <code>IPackageFragment</code>
	 */
	public void setPackagesToUnseal(IPackageFragment[] packagesToUnseal) {
		fPackagesToUnseal= packagesToUnseal;
	}
	/**
	 * Tells whether a description of this JAR package must be saved
	 * to a file by a JAR description writer during the export operation.
	 * <p>
	 * The JAR writer defines the format of the file.
	 * </p>
	 * 
	 * @return	<code>true</code> if this JAR package will be saved
	 * @see #getDescriptionLocation()
	 */
	public boolean isDescriptionSaved() {
		return fSaveDescription;
	}
	
	/**