Skip to main content

The difference between emulation and simulation?


Explain by Using as an example.
You want to duplicate the behavior of an old HP calculator, there are two options:
  1. You write new program that draws the calculator's display and keys, and when the user clicks on the keys, your programs does what the old calculator did. This is a Simulator
  2. You get a dump of the calculator's firmware, then write a program that loads the firmware and interprets it the same way the microprocessor in the calculator did. This is an Emulator
The Simulator tries to duplicate the behavior of the device.
The Emulator tries to duplicate the inner workings of the device.
More examples,
For Emulation,
You may know something about the case between Google and Oracle. In Brief, google implemented the same APIs(For Android) the java library provided to Java Developers to development Java applications. We can call it JRE Emulation Library. Also, in Google's GWT, it did similiar thing(weird that Oracle did not sue Google For this :) ) .
The Packages google emulated Java's Library.
java.io
java.lang
java.util

For Simulator,
when you develop Android , IOS or Windows phone applications, you don't need to plug in real device, just use the Simulator.



Comments

Post a Comment

Popular posts from this blog

Stretch a row if data overflows in jasper reports

It is very common that some columns of the report need to stretch to show all the content in that column. But  if you just specify the property " stretch with overflow' to that column(we called text field in jasper report world) , it will just stretch that column and won't change other columns, so the row could be ridiculous. Haven't find the solution from internet yet. So I just review the properties in iReport one by one and find two useful properties(the bold  highlighted in example below) which resolve the problems.   example: <band height="20" splitType="Stretch" > <textField isStretchWithOverflow="true" pa...
4 comments
Read more

Live - solving the jasper report out of memory and high cpu usage problems

I still can not find the solution. So I summary all the things and tell my boss about it. If any one knows the solution, please let me know. Symptom: 1.        The JVM became Out of memory when creating big consumption report 2.        Those JRTemplateElement-instances is still there occupied even if I logged out the system Reason:         1. There is a large number of JRTemplateElement-instances cached in the memory 2.     The clearobjects() method in ReportThread class has not been triggered when logging out Action I tried:      About the Virtualizer: 1.     Replacing the JRSwapFileVirtualizer with JRFileVirtualizer 2.     Not use any FileVirtualizer for c...
1 comment
Read more

JasperReports - Configuration Reference

Data Source / Query Executer net.sf.jasperreports.csv.column.names.{arbitrary_name} net.sf.jasperreports.csv.date.pattern net.sf.jasperreports.csv.encoding net.sf.jasperreports.csv.field.delimiter net.sf.jasperreports.csv.locale.code net.sf.jasperreports.csv.number.pattern net.sf.jasperreports.csv.record.delimiter net.sf.jasperreports.csv.source net.sf.jasperreports.csv.timezone.id net.sf.jasperreports.ejbql.query.hint.{hint} net.sf.jasperreports.ejbql.query.page.size net.sf.jasperreports.hql.clear.cache net.sf.jasperreports.hql.field.mapping.descriptions net.sf.jasperreports.hql.query.list.page.size net.sf.jasperreports.hql.query.run.type net.sf.jasperreports.jdbc.concurrency net.sf.jasperreports.jdbc.fetch.size net.sf.jasperreports.jdbc.holdability net.sf.jasperreports.jdbc.max.field.size net.sf.jasperreports.jdbc.result.set.type net.sf.jasperreports.query.chunk.token.separators net.sf.jasperreports.query.executer.factory.{language} net.sf.jasperreports.xpath....
Post a Comment
Read more