String str = "hello world!";
// capitalize first letter
String output = str.substring(0, 1).toUpperCase() + str.substring(1);
// print the string
System.out.println(output);
// Hello world!
//You can user the WordUtils class from apache commons-text library
WordUtils.capitalize(str)
String str = "java";
String cap = str.substring(0, 1).toUpperCase() + str.substring(1);