Java 14 Made Easy: Records, Pattern Matching, Switch Expressions & Clear NPEs

Java 14 adds several language features that simplify common coding patterns and improve error reporting.

1. Record

Traditionally, defining a simple data class requires writing fields, constructors, getters, setters, and overriding toString, equals, and hashCode. The example below shows the verbose version:

public class Student {
    private int id;
    private String name;

    public Student() {
        // ...
    }

    public int getId() {
        // ...
    }

    // ... other getter()/setter()
    public boolean equals(Student s) {
        // ...
    }
    public int hashCode() {
        // ...
    }
    public String toString() {
        // ...
    }
}

With record , the same class can be declared in a single line, and the compiler automatically generates the boilerplate methods: record Student(int id, String name) { } Records define a final class with immutable fields, so no setters are generated and field access is direct.

2. Pattern Matching

Traditional instanceof checks require a separate cast:

public void attendTo(Animal a) {
    if (a instanceof Dog) {
        walk((Dog) a);
    } else if (a instanceof Cat) {
        cleanLitterBoxOf((Cat) a);
    } else {
        returnToStore(a);
    }
}

Pattern matching combines the type test and variable declaration:

public void attendTo(Animal a) {
    if (a instanceof Dog d) {
        walkDog(d);
    } else if (a instanceof Cat c) {
        cleanLitterBoxOf(c);
    } else {
        returnToStore(a);
    }
}

This eliminates the explicit cast and makes the code clearer.

3. Switch Expressions

Prior to Java 14, switch was a statement. It can now be used as an expression that yields a value:

int i = ...;
String s = switch (i) {
    case 0 -> "none";
    case 1 -> "one";
    default -> "many";
};

Another example shows a compact way to compute the number of days in a month:

int days = switch (month) {
    case 1, 3, 5, 7, 8, 10, 12 -> 31;
    case 4, 6, 9 -> 30;
    case 2 -> 28;
    default -> 0;
};

4. Improved NullPointerException

Traditional NPE messages only indicate the line where the null occurred, leaving developers to guess which method returned null:

Exception in thread "main" java.lang.NullPointerException
    at xxx.HelpfulNullPointerException.main(HelpfulNullPointerException.java:10)

Java 14 enhances the message to show the exact null source:

Exception in thread "main" java.lang.NullPointerException:
  Cannot invoke "String.toLowerCase()" because the return value of
  "xxx.HelpfulNullPointerException$PersonalDetails.getEmailAddress()" is null
    at xxx.HelpfulNullPointerException.main(HelpfulNullPointerException.java:10)

These features collectively reduce boilerplate, make type checks safer, enable more expressive control flow, and provide clearer diagnostics.