Java Server

Important Oracle JDK License Update The Oracle JDK License has changed for releases starting April 16, 2019. The server may still need access to sites outside the firewall, for example, to use the administrative console to fetch and install a JDBC driver. In this tutorial, we will learn how to create a simple HTTP Server in Java, which can listen HTTP request on a port let's say 80 and can send response to client. Jetty can be easily embedded in devices, tools, frameworks, application servers, and clusters. der -outform der From here the easiest thing to do is import this certificate into Java's system truststore. org where server. substitute your password and migrate your Minecraft account in case you have not any greater yet. ServerSocket is a java. Download Minecraft: Java Edition server software. Free, fast and easy way find java server engineer jobs of 1. According to the Weblogic, Weblogic Application Server is world's #1 Java application server. 1, because the Server and Client running on the same machine. Java Download » What is Java? » Do I have Java? » Need Help? » Uninstall About Java. In terms which may sound more familiar, it's a Java-based web framework. jrDesktop is an open source software licensed under the terms of the GNU Public License (GPL). It's the platform for launching careers, exploring human-to-digital interfaces, architecting the world's best applications, and unlocking innovation everywhere—from garages to global organizations. A servlet is a Java class implementing the javax. Binding is nothing but dedicating the port number to. Play Framework makes it easy to build web applications with Java & Scala. Although other server-side languages can be used to create a WebSocket server, this example uses Oracle Java to simplify the example code. 0 adds several frequently requested features, like support for non-blocking I/O, better start-up performance and automatic iteration over paginated responses. As you can see, this sample code is a complete Java socket client class that you can use for your own tests. Once the Connection is at hand, it works exactly the same as the one obtained through the ServerConnection class in Server. WebDAV server with Oracle back-end example is a Class 2 server that runs as Java Web Application in Apache Tomcat, Glassfish or JBoss and stores all data including locks, file content and custom properties in Oracle database. In case you prefer to use Java NIO instead of Java Networking (standard API), then you can also use a ServerSocketChannel instead of the java. Demonstrates how to connect to an SSL server and verify its SSL certificate. If you are running NGINX on the same server of the Java, the best practice is to deny access to port 8080 so only NGINX can access it. org without administrative privileges or without system integration? How do I install OpenOffice. It's designed to be a complete and portable FTP server engine solution based on currently available open protocols. Jetty is a Servlet container and a web server. Gitblit includes a backup mechanism (*federation*) which can be used to backup repositories and, optionally, user accounts, team definitions, server settings, & Groovy push hook scripts from your Gitblit instance to another Gitblit instance or to a Gitblit Federation. 8 is available for Minecraft Servers! * Note: Linux users should avoid using OpenJDK 6 for server hosting, as it has been known to cause issues Only the JRE version is required, however, Java JDK will still work. Play Framework makes it easy to build web applications with Java & Scala. JavaServer Faces (JSF) is the "official" component-based view technology in the Java EE web tier. In this example, the Java client is sending an HTTP request to an external web server. On Windows Server 2008, I was trying to get Java installed, but Internet Explorer kept saying that I was unable to download the file because of my security settings. It correctly supports a variety of file types, allowing delivery of multimedia web content and allows many HTTP requests to be dealt with simultaneously. For a class I am taking, we are testing out a simple UDP Server and UDP Client to demonstrate what each one does and how sockets work. on Aug 11, 2013 at 01:22 UTC. And Java 7 is the latest which have less bugs and better performance + much more, i'm running my server on the latest Server JRE (7u40) Bye and regards!. The Java Servlet, JavaServer Pages, Java Expression Language and Java WebSocket specifications are developed under the Java Community Process. By the help of it, users log on to a host computer and perform work as if they are working on an isolated computer. Here we give as 127. Go to the Certificates Tab/Server Certificates. Although other server-side languages can be used to create a WebSocket server, this example uses Oracle Java to simplify the example code. Welcome to the ACME Java mines! ACME Labs is exploring the use of Java for fun and profit. The Java WebDAV Server supports PUT requests with Content-Range header as well as it can report how much of the file content was successfully saved if upload was interrupted and must be resumed. It was a Java applet and did a simple staged download and upload. Java SSL handshake with Server Name Identification (SNI) SNI (Server Name Indication) was an extension added to TLS, to support multiple digital certificates per host name on a single IP. 6 has been deprecated. Developer friendly. I'm running my server on Java 8 and my startup command is just. Server makes an HTTP request passing the name of the Java class which implements the method along with any specified arguments to a servlet which knows how to execute the specified method. Java Download » What is Java? » Do I have Java? » Need Help? » Uninstall About Java. Java Network Programming, Manning Publications, 1997. First make sure you can use java from the command line. org is where you can learn about the technologies developed at Eclipse to make Internet of Things (IoT) development simpler. java ReverseServer 9090 The server is up and running, waiting for incoming requests from clients: Server is listening on port 9090 Now, let's create a client program. Welcome to the ACME Java mines! ACME Labs is exploring the use of Java for fun and profit. TCP is a two-way communication protocol. This can be useful to you for a number of reasons: To capture traffic between a client and server. Hannes Wallnöfer has provided an excellent implementation of XML-RPC for Java. The client connection with PHP and with generated local classes for Java, with java. Typically OPC UA is used for data acquisition, process monitoring, device diagnostics, etc. i have to make an application with client-server system with java (client application for on android and server application for on PC) and i asked to make the class diagram for both in one class diagram (not seperately). Starting with the installation of Glassfish 4 application server, you’ll then progress to developing powerful applications for it. I don't believe you will be able to do this in one big statement, unless your Sql connectivity tech (e. Java is becoming more and more popular as a tool for building Web applications, thanks to Java servlets and Java Server Pages. Creating a simple Chat Client/Server Solution. in my server MySQL taking more than 200% CPU usage. 0 and following versions require Java 1. It is intended to speed up applications by providing a means to manage cached data of various dynamic natures. Product downloads are available for many Red Hat products, such as Red Hat Enterprise Linux and Red Hat JBoss Enterprise Application Platform (based on WildFly. ServerSocket class provides a mechanism for the server application to listen to clients and establish connections with them. It’s also a core language of Google’s Android mobile application development, which brought it back onto developers’ radars in. Apache Tomcat is a J2EE application server, which means, it can run web applications that have been written in java (J2EE) If you ever want to run an application written in PHP in apache tomcat, you can’t with the default setup; Why would you want to run a PHP application on a J2EE server?. My questions follow the programs. For more information, see vnc_Server_getPeerAddress(). It provides an easy way to implement networking protocols. Welcome to Apache FtpServer¶ Overview¶ The Apache FtpServer is a 100% pure Java FTP server. This java server engineer sample job description can assist in your creating a job application that will attract job candidates who are qualified for the job. I am using AWS windows server 2016 64- bit. Any idea, why it is happening? thanks. I did a Java program that basically implemented a sort of chat between a client and a server. Java Server Pages is a technology that helps software developers to create platform independent dynamic web applications rapidly. keytool can be used to generate a local Server Certificate - the certificate is valid but it is not. Nagios XI provides complete monitoring of Java applications and servers. Server-side Java code is written to the ref_send API, which defines the asynchronous invocation interface. The Java Language server supports sockets, named pipes, and standard streams of the server process to communicate with the client. 0 Open Source license - our codebase will be open forever. On Windows Server 2008, I was trying to get Java installed, but Internet Explorer kept saying that I was unable to download the file because of my security settings. Apache Olingo is a Java library that implements the Open Data Protocol (OData). Many universities contribute to UniTime, producing their own features and adaptations that are played back into the software for the general good. The JRE is used to run a broad variety of Java programs including Java applications on desktops. - For memory parameter, I suggest you can copy all the parameters from existing server node including Java memory this will make sure that you have same parameters across all the serer nodes. java with IE HttpsEchoer. A Web Server in 150 Lines A simple but functioning HTTP file server in Java. Web apps with Java and Spring. In most cases you should set the JRE_HOME environment variable, but if it is not set, Confluence will use JAVA_HOME. Socket class represents a socket, and the java. The project is developed under the Eclipse Foundation. In Windows RT, Java and other add-ons aren't supported by Internet Explorer or Internet Explorer in the desktop. A computer was usually placed within a large room and the information to be processed had to be taken to it. dll manually, then it's clear that Siebel can also not find it. Pebble is a lightweight, open source, Java EE blogging tool. Java for macOS 2017-001 installs the legacy Java 6 runtime for macOS 10. HSQLDB (HyperSQL DataBase) is the leading SQL relational database software written in Java. The following section describes how to initially setup a project to compile a CMIS server. 6, there's a built-in HTTP server included with the JDK. This code stream has many more features than the 2. A server plugin is a NetBeans plugin that facilitates integration with a web server or a Java EE server, including starting/stopping the server, deployment, debugging, user interface for server registration and basic administration, handling server-specific data and other tasks. Screenshot on Echo Server UDP Example Java. Starting with the installation of Glassfish 4 application server, you’ll then progress to developing powerful applications for it. This package has no dependencies. Welcome to Apache FtpServer¶ Overview¶ The Apache FtpServer is a 100% pure Java FTP server. Derby is based on the Java, JDBC, and SQL standards. The pro-Trump forces eagerly spread these stories, fervently believing them only because they reinforced their belief that Hillary was the daughter of Satan. Flazr is a Java implementation of protocols such as RTMP used for multimedia streaming. Follow the installation instructions on the Java website. hallo, could somebody please show me an example for sending a string from client to server. Rather than processing the incoming requests in the same thread that accepts the client. listens for HTTP GET requests and sends back files sets MIME type based on file extensions simple access restrictions redirects directory requests Read command-line arguments and open server socket:. Its footprint is so small you can easily embed it in any Java-based solution. The service ticket is a short-lived one-time-use token redeemable at the CAS server for a user identifier (and optionally, user attributes). Verified employers. The RTSP server stops recording when it receives an RTP BYE, after a timeout or when the SIP server receives a SIP BYE from the caller and generates an RTSP TEARDOWN. When working with "Java projects" in VS Code, you must have the necessary extensions installed to work with those project files. If you get a start up message mentioning version errors double check with "java -version". The JRE is used to run a broad variety of Java programs including Java applications on desktops. 2010-02-10 cmislib contribution accepted. jar from distribution archive to your build path. Publish/Subscribe semantics delivers messages to all subscribers of a topic. Built for productivity. That is, a pool of That is, a pool of connections can be shared by different client requests. Apache httpd 2. This code stream has many more features than the 2. Socket class represents a socket, and the java. It's small, fast and feature-rich with unrivalled ease of installation and use. I got it working for now, but in my "ideal" world since every release of an Atlassian product includes it's own JRE, I will automate the above steps into a script to inject the "peer" applications' (hosted on other servers) certificates into only the "vendored" JRE cacerts to allow them to. The Jira Java APIs are typically used when building Plugins2 apps (for Jira Server). Truth is ever to be found in simplicity, and not in the multiplicity and confusion of things. The Cloud SDK for Java includes a local development server for testing your application on your computer. JGit has very few dependencies, making it suitable for embedding in any Java application, whether or not the application is taking advantage of other Eclipse or OSGi technologies. For PCs running Windows 8. Server makes an HTTP request passing the name of the Java class which implements the method along with any specified arguments to a servlet which knows how to execute the specified method. The Open. This should be very useful when we want to test our uPixelstech, this page is to provide vistors information of the most updated technology information around the world. This will only take. Log on to the ePolicy Orchestrator (ePO) console. This is a very small standalone web server written in Java. Full-time, temporary, and part-time jobs. The MongoDB Wire Protocol is implemented with Netty. On top of this implementation, the Wink Server module provides a set of additional features that were designed to facilitate the development of RESTful Web services. Combine APM Insight with Site24x7 Server Monitoring to increase your Java environment monitoring capabilities. JM2PC - Java Mobile to PC. Java for macOS 2017-001 installs the legacy Java 6 runtime for macOS 10. Sorry, you need to have the java plugin enabled for the applet to work. Find answers for the crossword clue: Java server. For more information, see vnc_Server_getPeerAddress(). Server-side technology could be JSP/Servlet, PHP, Coldfusion, CGI or Microsoft ASP. Selenium Standalone Server. The ports can be changed if needed in the MCS server configuration page. Blog content is stored as XML files on disk and served up dynamically, so there's no need to install a database. [Commercial]. Customer service software powered by Desk. Thank you for downloading this package of the Java™ Platform, Standard Edition Runtime Environment (JRE™). org? How can I install OpenOffice. In this tutorial, we will learn how to create a simple HTTP Server in Java, which can listen HTTP request on a port let's say 80 and can send response to client. The main difference is the server loop. In most cases you should set the JRE_HOME environment variable, but if it is not set, Confluence will use JAVA_HOME. However, there are some limits to what web browsers can do. In this tutorial, we'll use the Java Client for NATs to connect to a NATS Server and publish and receive messages. With Quercus, PHP applications automatically take advantage of Java application server features just as connection pooling and clustered sessions. The 70+ widgets in Telerik UI for JSP are jQuery-based and 40+ of them come with server-side wrappers. Starting out as a YouTube channel making Minecraft Adventure Maps, Hypixel is now one of the largest and highest quality Minecraft Server Networks in the world, featuring original games such as The Walls, Mega Walls, Blitz Survival Games, and many more! The administration works very hard to bring. Apache SSHD is a 100% pure java library to support the SSH protocols on both the client and server side. Get free access to product downloads for development use through the Red Hat Developer Program. Find answers for the crossword clue: Java server. I have been working with NIO since last 2 years and would like to share simple Server-Client code for my readers who are free to use this code in their production environment. Here's the code: import java. JAVA SOCKS Server It is a SOCKS server written entirely in Java, which supports both SOCKS4 and SOCKS5 protocols. Rather than processing the incoming requests in the same thread that accepts the client. Example Server. Here we give as 127. If you're using the installer, you don't need to do this. Server makes an HTTP request passing the name of the Java class which implements the method along with any specified arguments to a servlet which knows how to execute the specified method. Write text to a character-output stream, buffering characters so as to provide for the efficient writing of single characters, arrays, and strings. JSP page are converted by the web container into a Servlet instance. Product downloads are available for many Red Hat products, such as Red Hat Enterprise Linux and Red Hat JBoss Enterprise Application Platform (based on WildFly. Java Powers Our Digital World. To run/install the server use the according scripts in the /bat folder To start the user interface use the script under /bat folder. You can access it by choosing SAP NetWeaver. Java SE 8 and the Eclipse Neon IDE was used. With QuickServer you can concentrate on just the application logic/protocol on hand. Run your Java code on Azure Web Apps—a Linux-based, managed application platform with full support for Java SE based apps, Tomcat, Spring, and custom Docker containers. A connection pool means simultaneous transfers are supported, and a powerful scripting engine and command shell are part of the package. Access your cloud dashboard, manage orders, and more. Many web hosting company promise lot of things but few of them only fulfills their promises. Please note that CMIS comes with two built-in servers. How To Create a Java Server Application. In this post, I will create a HTTPS server and HTTPS client demo which can establish HTTPS communication between a server and a client using Java. My options for changing the security zone settings were grayed out, and adding the Java website to my trusted sites did not work. This JSP Scripting Element allows you to put in a lot of Java code in your HTML code. JSP allows Java code and certain predefined actions to be interleaved with static web markup content, such as HTML. Deployment and operations of the Application Servers has changed little over the years. The Client program remains unchanged. The client is the furthest along, and the current release emulates the most basic functionality of the rsync program. 8 will require Java 7¶ The Apache Lucene/Solr committers decided with a large majority on the vote to require Java 7 for the next minor release of Apache Lucene and Apache Solr (version 4. Anything is possible. It is also not blocked by the firewall (it is white listed). 7 and Java 1. 10 Yosemite, macOS 10. JM2PC - Java Mobile to PC. Since Java 1. Whether you're using J2EE or writing your own, you will need to understand the fundamental concepts of server-based Java. Fig 1: Basic proxy server authentication flow. Welcome Apache Ant™ Apache Ant is a Java library and command-line tool whose mission is to drive processes described in build files as targets and extension points dependent upon each other. Additional features in Java APM. If it still does not work:. Java in VS Code. after a request is received, a client socket is generated. Apply to Sohum Inc. Choosing between the different Java apps servers can be a big challenge for developers who are. Port Requirements. However, in this article, we will discuss about building a multi-threaded server in Java. In this tip we will download and install the JDBC driver, set the classpath to the driver, examine the code, and then execute the program from the Windows command prompt. Java can be used to create complete applications that may run on a single computer or be distributed among servers and clients in a network. Chat with Friends or Colleagues securely! Easy Chat Server is a easy, fast and affordable way to host and manage your own real-time communication software, it allows friends/colleagues to chat with you through a Web Browser (IE, Safari, Chrome, Opera etc. The mail server just is as important as a web server is. It's small, fast and feature-rich with unrivalled ease of installation and use. Binding is nothing but dedicating the port number to. You will be prompted for the DN information. Java is a programming language used for both client-server programs, web applications and Android development. ) JavaServer Faces (JSF) is a Java-based Web. This application helps the users connected in an intranet environment to communicate with electronic mails, and it handles all the works related to mails. I'm running java war file in tomcat server that uses hibernate JPA to perform MySQL operation I did slowSQLQuerylogs also but there is nothing that. i have to make an application with client-server system with java (client application for on android and server application for on PC) and i asked to make the class diagram for both in one class diagram (not seperately). Developer friendly. Can I install Java after I install OpenOffice. How can I tell what version of Java is currently installed? This thread is locked. With Windows Azure, you can use a virtual machine to provide server capabilities. Update Java from server. Whether you're using J2EE or writing your own, you will need to understand the fundamental concepts of server-based Java. Socket class represents the socket between the client and the server, and the java. The driver is available at no additional charge and provides Java database connectivity from any Java application, application server, or Java-enabled applet. 8 are now available, while Java 1. Wijaya Komunika. Java is an object oriented language and some concepts may be new. We have 1 answer for this clue. Java is a server-side programming language that's widely known, popular for enterprise-level applications, and ideal for high-traffic sites that need room to grow. What is Simple Java Server? Simple Java Server (SJS) is an architecture akin to Unix' inetd process. Any idea, why it is happening? thanks. 00 KB [12: 02: 02 INFO]: [Characters] Enabling Characters v6. Up and running in 55 seconds. I don't believe you will be able to do this in one big statement, unless your Sql connectivity tech (e. will run fine on it. HSQLDB (HyperSQL DataBase) is the leading SQL relational database software written in Java. This information is only relevant if you're installing Confluence manually on a Windows server. I'm assuming you mean "how can I have multiple client socket connections to my server process implemented in Java?" A web server is a good example of this scenario. Java can be used to create complete applications that may run on a single computer or be distributed among servers and clients in a network. private static class server_task implements Runnable { @Override public void run. ServerSocket class provides a mechanism for the server application to listen to clients and establish connections with them. Home; Java Tutorial; Language; Data Type; Operators; Statement Control; A multithreaded. Java allows you to play online games, chat with people around the world, calculate your mortgage interest, and view images in 3D, just to name a few. The compiled pages, as well as any dependent Java libraries, contain Java bytecode rather than machine code. Home; Java Tutorial; Language; Data Type; Operators; Statement Control; A multithreaded. This code stream has many more features than the 2. This report shows the usage statistics of Java as server-side programming language on the web. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. HttpClient Overview. *; import java. The project is developed under the Eclipse Foundation. It can be used check any server or client at uses TCP or UDP protocol to communicate. Come to this session and learn from our real-world experiences of getting our flagship WebSphere Application Server products up-and-running on Java SE 9 (and integrated with our OSGi runtime). hallo, could somebody please show me an example for sending a string from client to server. 0_ version in the current directory. The Microsoft Java Virtual Machine is no longer available from Microsoft directly due to legal wrangling with SUN, however it still can be downloaded Microsoft VM build 3810 for Windows Vista, Windows XP, Windows 2000, Windows 95/98, Windows Me, Windows NT 4. Here, we are using 6666 port number for the communication between the client and server. net package. JVM is launched in client mode by default in SUN/Orace JDK. 8% of all the websites whose server-side programming language we know. Sun Microsystems, the. Here's the code: import java. If you are like many people, you probably get your news and other important information from the internet. Here we give as 127. Java PDF SDK / API PDF Viewing Component PDF Studio for Mac, Windows, Linux Android PDF Tools PDF Automation Server Contact Support If you do not find the answer to your question, email us. // This is our server task. Apache Tomcat is a J2EE application server, which means, it can run web applications that have been written in java (J2EE) If you ever want to run an application written in PHP in apache tomcat, you can’t with the default setup; Why would you want to run a PHP application on a J2EE server?. By the help of it, users log on to a host computer and perform work as if they are working on an isolated computer. LPD (Line Printer Daemon) implementation in Java This code accepts print jobs over the network and captures them, so a programmer can then manipulate these print jobs. public String getPeerAddress (Connection connection) throws Library. Here is an example of how to extend a very simple client-server demo program into a fully functioning (but simple) Chat Client/Server package. Developer friendly. It's the platform for launching careers, exploring human-to-digital interfaces, architecting the world's best applications, and unlocking innovation everywhere—from garages to global organizations. crt -out server. Java is at the heart of our digital lifestyle. , the commands sent by the client are consistent with what the. EnumSet getPermissions (Connection connection) throws. Record and Upload Voice Messages Home: Download: Docs: Examples: Login: Support: Contact Us: JavaSonics ListenUp is no longer for sale. Servlet technology is used to create a web application (resides at server side and generates a dynamic web page). It is developed by an open source community and can be downloaded for free from Eclipse. It's the most widely-used Java-based cache because it's robust, proven, full-featured, and integrates with other popular libraries and frameworks. java ReverseServer 9090 The server is up and running, waiting for incoming requests from clients: Server is listening on port 9090 Now, let’s create a client program. With Quercus, PHP applications automatically take advantage of Java application server features just as connection pooling and clustered sessions. But because communication with the FTP server is across the network using sockets, it can be used to test FTP client code written in any language. Integrated into the Java Ecosystem. Root and Intermediate Certificates. There is a very active user community and there are many companies who use Axis for Web services support in their products. Additional features in Java APM. It's a bit tricky, but you can do it!. If you are running NGINX on the same server of the Java, the best practice is to deny access to port 8080 so only NGINX can access it. This component provides access to such settings, in a convenient and simple-to-use way. by Danny7062. Socket class represents a socket, and the java. The OPC UA Java SDK allows efficient development of OPC UA clients and servers, because the Server SDK is bundled with the Client SDK (see the Client SDK product page for more information). The only difference is that the new versions are distributed directly as a rpm package so instead of the shell command which unpacks and installs the ". On top of this implementation, the Wink Server module provides a set of additional features that were designed to facilitate the development of RESTful Web services. This had two. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. ) JavaServer Faces (JSF) is a Java-based Web. vmargs: Extra VM arguments used to launch the Java Language Server. These include a directory server, which has been certified as LDAP v3 compliant by the Open Group (ApacheDS), and Eclipse-based directory tools (Apache Directory Studio). This is a very small standalone web server written in Java. Welcome to Apache Maven. Java production debuggers are quite easy to use. Customer service software powered by Desk. jks 'Yourdomain' is the name of the domain you are securing. The resulting page is compiled and executed on the server to deliver a document. On a 64-bit capable jdk only the Java HotSpot Server VM is supported so the -server option is implicit. Java on the server is here to stay. Once retrieved, the server-side program uses the information to formulate the HTML response, then the Web server sends it back to your Web browser. Peladen (bahasa Inggris: server) merupakan sebuah sistem komputer yang menyediakan jenis layanan tertentu dalam sebuah jaringan komputer. Java allows you to play online games, chat with people around the world, calculate your mortgage interest, and view images in 3D, just to name a few. Sign up for a free trial. This happens if it is on the webpage : The PHP client just times out and does not successfully connect to the server. JAMon allows developers to track their applications performance and behavior using predefined modules. It is one of the most popular programming languages and runs on all platforms via the Java Virtual Machine (JVM). ServerSocket sersock = new ServerSocket(5000); The server has two jobs - one is, as expected, to communicate and the other is binding the connection on the port number 5000. JAVA SOCKS Server It is a SOCKS server written entirely in Java, which supports both SOCKS4 and SOCKS5 protocols. It is rapidly evolving across several fronts to simplify and accelerate development of modern applications. Rhino is a JavaScript interpreter written in Java that can also bridge JavaScript to Java server-side. Unpack the tarball and install the Server JRE. 1, because the Server and Client running on the same machine. EnumSet getPermissions (Connection connection) throws. ServerSocket class provides a mechanism for the server application to listen to clients and establish connections with them. General purpose of the Web server is running and debugging servlets. It was created by Sun Microsystems. java ReverseServer 9090 The server is up and running, waiting for incoming requests from clients: Server is listening on port 9090 Now, let's create a client program.