Tutorial by Examples: l

Executable JAR files are the simplest way to assemble Java code into a single file that can be executed. *(Editorial Note: Creation of JAR files should be covered by a separate Topic.) * Assuming that you have an executable JAR file with pathname <jar-path>, you should be able to run it as f...

Suppose that we want to create a simple Hello World document: In iText 5, this would be done like this: public void createPdf(String dest) throws DocumentException, IOException { Document document = new Document(); PdfWriter.getInstance( document, new FileOutputStream(des...

Suppose that we wanted to create a simple Hello World document: In iText 7, we could do that like this: public void createPdf(String dest) throws IOException { PdfDocument pdf = new PdfDocument(new PdfWriter(dest)); Document document = new Document(pdf); document.add(new Paragraph...

A session is simply an array consisting of the following user information: The user's unique Session ID (this is a statistically random string with very strong entropy, hashed with MD5 for portability, and regenerated (by default) every five minutes) The user's IP Address The user's User Agent ...

In the .bashrc or .bash_profile, adding: export MYSQL_PS1="\u@\h [\d]>" make the MySQL client PROMPT show current user@host [database].

Objective-C NSPredicate *predicate = [NSPredicate predicateWithBlock:^BOOL(id item, NSDictionary *bindings) { return [item isKindOfClass:[UILabel class]]; }]; Swift let predicate = NSPredicate { (item, bindings) -> Bool...

An NSPredicate can use substitution variables to allow values to be bound on the fly. Objective-C NSPredicate *template = [NSPredicate predicateWithFormat: @"self BEGINSWITH $letter"]; NSDictionary *variables = @{ @"letter": @"r" }; NSPredicate *beginsWithR = [templ...

Objective-C NSArray *heroes = @[@"tracer", @"bastion", @"reaper", @"junkrat", @"roadhog"]; NSPredicate *template = [NSPredicate predicateWithFormat:@"self BEGINSWITH $letter"]; NSDictionary *beginsWithRVariables = @{ @"letter&qu...

To prevent memory leaks, one should not forget to close an input stream or an output stream whose job is done. This is usually done with a try-catch-finally statement without the catch part: void writeNullBytesToAFile(int count, String filename) throws IOException { FileOutputStream out = null...

You can bind event listeners to the EventSource object to listen to different events channels using the .addEventListener method. EventSource.addEventListener(name: String, callback: Function, [options]) name: The name related to the name of the channel the server is emitting events to. callb...

make a publisher account add an asset in the publisher account download the asset store tools (from the asset store) go to "Asset Store Tools" > "Package Upload" select the correct package and project folder in the asset store tools window click upload submit your asse...

Save aps.cer to a folder Open "Keychain access" and export the key that is under that certificate to a .p12 file (call it key.p12). To do that right click on it and choose Export. Save it to the same folder as step 1. On export you will be prompted for a password. Make something u...

Using redux directly with react might seem little difficult, As for every component you want to update when store changes, you have to subscribe that component to the redux store React Redux takes care of all these and makes it really easy to write components that can request the data it needs from...

As seen in previous examples, basic use of this script is: python setup.py install But there is even more options, like installing the package and have the possibility to change the code and test it without having to re-install it. This is done using: python setup.py develop If you want to p...

When an application has not been packaged as an executable JAR, you need to provide the name of an entry-point class on the java command line. Running the HelloWorld class The "HelloWorld" example is described in Creating a new Java program . It consists of a single class called HelloWo...

A Java entry-point class has a main method with the following signature and modifiers: public static void main(String[] args) Sidenote: because of how arrays work, it can also be (String args[]) When the java command starts the virtual machine, it loads the specified entry-point classes and...

Detailed instructions on getting promise set up or installed.

Swift 2.3 let url = NSURL(string: "http://google.com/lastPath") let lastPath = url?.lastPathComponent Swift 3.0 let url = URL(string: "http://google.com/lastPath") let lastPath = url?.lastPathComponent

GET your REST data and store in a PowerShell object: $Post = Invoke-RestMethod -Uri "http://jsonplaceholder.typicode.com/posts/1" Modify your data: $Post.title = "New Title" PUT the REST data back $Json = $Post | ConvertTo-Json Invoke-RestMethod -Method Put -Uri "h...

GET your REST data and store in a PowerShell object: $Users = Invoke-RestMethod -Uri "http://jsonplaceholder.typicode.com/users" Modify many items in your data: $Users[0].name = "John Smith" $Users[0].email = "[email protected]" $Users[1].name = "Jane S...