In Spring Web MVC, we can use the @PathVariable annotation to access the captured URI variables. Table of contents: 1. Basic Mapping 2. Basic Mapping – Different Name 3. Basic Mapping – Class and method levels 4. Multiple Captured URI Variables 5. Multiple Captured URI Variables – Map Version 6. Regex Mapping 7. @PathVariable variables […]
In Java, we can use Integer.valueOf(String) to convert a String to an Integer object; For unparsable String, it throws NumberFormatException. Integer.valueOf("1"); // ok Integer.valueOf("+1"); // ok, result = 1 Integer.valueOf("-1"); // ok, result = -1 Integer.valueOf("100"); // ok Integer.valueOf(" 1"); // NumberFormatException (contains space) Integer.valueOf("1 "); // NumberFormatException (contains space) Integer.valueOf("2147483648"); // NumberFormatException (Integer max […]
In Java 8, we can use .map(Object::toString) to convert an Optional<String> to a String. String result = list.stream() .filter(x -> x.length() == 1) .findFirst() // returns Optional .map(Object::toString) .orElse(""); Samples A standard Optional way to get a value. Java8Example1.java package com.mkyong; import java.util.Arrays; import java.util.List; import java.util.Optional; public class Java8Example1 { public static void main(String[] […]
Java 8 has introduced a new class Optional in java.util package. It is used to represent a value is present or absent. The main advantage of this new construct is that No more too many null checks and NullPointerException. It avoids any runtime NullPointerExceptions and supports us in developing clean and neat Java APIs or […]
