How to compare strings in Java?
String comparison in Java In Java, string comparison is used to compare two string values for equality or inequality. There are two main ways to compare strings in Java: using …
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Repeating a string using StringBuilder
Suppose you have the string ‘qwe’ and you need to repeat string ‘n’ times. Here’s how to do it with StringBuilder: Using StringBuilder and loop
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int n = 3; String in = "qwe"; StringBuilder b = new StringBuilder(n * in.length()); for (int i = 0; i < n; i += 1) { b.append(in); } String newString = b.toString(); |
How to add local jar files to a Maven project?
Imagine that you have implemented your java jar library and you need to connect it. Here are some examples of how to do it.
Read MoreHow to print a java array
Since Java 5 you can use Arrays.toString(arr) or Arrays.deepToString(arr) for arrays within arrays. Note that the Object[] version calls .toString() on each object in the array. The output is even …
Read MoreHow to parse JSON in Java
Google GSON library Let’s assume you have a class Book with just a title.
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private class Book { public String title; public Book(String title) { this.title = title; } } |
Create maven project and add dependencies.
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<dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> <version>2.8.5</version> </dependency> |
Then write this code to transform JSON into class: …
Read MoreCode style examples from top java development companies
I decided to collect code style examples from the well-known company in the java community. There are both direct links to setting up the checkstyle and examples of setting the …
Read MoreHow to generate word document with apache poi
Today we will continue the topic of generating office documents from the template. To generate a docx document, we use the apache poi library.
Read MoreSet java compiler version in pom
Suppose you write a project that must have mandatory support for java 1.6 and higher, but you only have java 9 installed and also want the compiled classes to be …
Read MoreWriting forEach with java 8 lambda
Let’s take a simple example. It’s easier, probably, and can not be – create a list of numbers and display it on the screen through the simplest cycle:
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List <Integer> numbers = Arrays.asList (1, 2, 3, 4, 5, 6); for (int number: numbers) { System.out.println (number); } |