How To Make Connect 4 In Java

[Giulia Satmary]

Iam trying to write a java program that will automatically download and name some of my favorite web comics. Since I will be requesting multiple objects from the same domain, I wanted to have a persistent http connection that I could keep open until all the comics have been downloaded. Below is my work-in-progress. How do I make another request from the same domain but different path without opening a new http connection?

According to the documentation here, HTTP persistence is being handled transparently in Java, although it gives you the options to control it too via http.keepAlive and http.maxConnections system properties.

The current implementation doesn'tbuffer the response body. Which meansthat the application has to finishreading the response body or callclose() to abandon the rest of theresponse body, in order for thatconnection to be reused. Furthermore,current implementation will not tryblock-reading when cleaning up theconnection, meaning if the wholeresponse body is not available, theconnection will not be reused.

According to this link -keepalive.html, HTTP connection reuse is enabled by default, you can use Wireshark to check the interactions between your client and server. The first request contains TCP and SSL handshakes(if your request is https), the subsequent requests fired in the keep-alive time, contains no TCP and SSL handshakes, just application data transfers.

Even though HttpURLConnection enable keep-alive by default, it is not guaranteed that HttpURLConnection uses same TCP connection for multiple HTTP requests. I faced same kind of issue when writing HTTPS client application. Solved this issue by using single instance of SSLContext, SSLSocketFactory and HttpsURLConnection.

I am trying to design a Java swing application. I want to experiment and use an MVC type of architecture whereby my UI is separated from the actual logic to access data and connect to a database. I have decided that I need to create a custom class that contains all the logic to connect to the database and then simply call methods from this class in my action event for any particular form and button. This way I can switch databases and all I need to do (if I have a large code base with many many forms) is change the JDBC connection string to connect to oracle instead of MySQL. So far I have the code to connect to a database but I am trying to figure out how I can make this a class.

Hi I know the language of HTML, CSS, and Java pretty well, but I have absolutely no idea on how to connect the java backend to frontend. I'm a complete amateur when it comes to programming, I just know the basics of each of these languages pretty well. I have my HTML and CSS coded to take in input, and I have all the calculations written in Java, so I have the functions of what I want to do all ready. I just don't know how to pass the user's input from the HTML, to the calculations in Java. I just run my Java code using scanner as the user input, but I want to integrate all my codes to make it a real website, and I think I'm going to need more than scanner for a user to input something on a website. I researched this topic multiple times, and I found information about serverlets and IntelliJ, but the information was confusing to me because again, I am a complete amateur in computer science (other than knowing these languages). Some also said the best way was to convert my java code to javascript, but I'm not sure if that's the best way. Any suggestions/information on what to do? Here's some of my java code (this part takes in user input, searches for the numbers before the last slash, then adds it to double firsum). Thanks!

Like cricket said, you can use a Java based web framework, I suggest Spring. This will provide all the functionality you need such as allowing you to save, index, search, write routes, etc for you application. Depending on how new you are, you probably want to make a basic CRUD app to get to know Spring.

You also want to think of your app from an architectural perspective. Do you want to make a single monolithic application that handles all your business logic, services, and the frontend - or do you want to make it more modular with microservices? (The second option is probably better). For this you are going to want to write an API that handles all your application's data (using Spring), and then make a small frontend app that gets that information and presents it.

However because you mention you are new to programming, I might suggest looking into a more "standard" server language than java. Don't get me wrong it is commonly used, but for beginners languages like php and python have much more front end connection "built in" to make your life easier.

You can use a Java micro web frameworks like Spring, Dropwizard, SparkJava to respond to HTTP requests and produce HTML content, but the common denominator to all frameworks is Servlets. Servlets respond to HTTP requests and can send "static files" (html, css, js, images, etc). Other options include full web application servers such as Tomcat, JBoss, GlassFish, Java EE

You'll also find that majority of websites are not using Java for hosting HTML/CSS/JS, as you can use any backend language with any front-end library via RESTful actions, which, on the web, are interacted with via Javascript (not Java Scanner objects)

I am new to Oracle, and am trying to run a simple example code with Java, but am getting this error when executing the code.. I am able to start up the listener via CMD and am also able to run SQL Plus. Can anyone give me a hand and tell me what I might be doing wrong?

(This strange error message is produced by Oracle's JDBC driver when it can't connect to the database server. 'Network adapter' appears to refer to some component of their code, which isn't very useful. Real network adapters (NICs) don't establish connections at all: TCP protocol stacks do that. It would have been a lot more useful if they had just let the original ConnectException be thrown, or at least used its error message and let it appear in the stack trace.)

Another thing you might want to check that the listener.ora file matches the way you are trying to connect to the DB. If you were connecting via a localhost reference and your listener.ora file got changed from:

then this can cause the error that you had unless you update your hosts file to accommodate for this. Someone might have made this change to allow for remote connections to the DB from other machines.

if you are facing this issue1- make sure you have downloaded oracle databases like oracle 11g,19c, 21c, or any latest databases.2- search for services in your computer or type win+r then services.mis then search for oracleservice you will find orcl or xe or any other sid like oracleserviceorcl;

In my case this happened in SOA (Oracle Weblogic) because the database tablespace was at its limit and in addition the machine's network adapter in OCI was intermittent, it was only resolved after restoring the machine's boot backup from a week ago and extend the tablespace.

I was having issues with this as well. I was using the jdbc connection string to connect to the database. The hostname was incorrectly configured in the string. I am using Mac, and the same string was being used on Windows machines without an issue. On my connection string, I had to make sure that I had the full url with the appending "organizationname.com" to the end of the hostname.

Just try to re-create connection. In my situation one of jdbc connection stopped working for no reason. From console sqlplus was working ok. It took me 2 hours to realize that If i create the same connection - it works.

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HyperSQL Database (HSQLDB) is a modern relational database system. Version 2.7.3 is the latest release of the all-new version 2 code. Written from ground up to follow the international ISO SQL:2023 standard, it supports the complete set of the classic features of the SQL Standard, together with optional features such as stored procedures and triggers.

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This guide covers the database engine features, SQL syntax and different modes of operation. The JDBC interfaces, pooling and XA components are documented in the JavaDoc. Utilities such as SqlTool and DatabaseManagerSwing are covered in a separate Utilities Guide.

The access tools are used for interactive user access to databases, including creation of a database, inserting or modifying data, or querying the database. All tools are run in the normal way for Java programs. In the following example the Swing version of the Database Manager is executed. The hsqldb.jar is located in the directory ../lib relative to the current directory.

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