What Happens When the Size of the String Pool Exceeds in Java?

What occurs if the size of the String Pool in Java exceeds its limits?

// Example of Java String Pool usage
String str1 = "Hello";
String str2 = "Hello"; // Reuses the same instance
String str3 = new String("Hello"); // Creates a new instance in heap

In Java, the String Pool is a special storage area in the Java heap that stores string literals. If the size of the String Pool exceeds its limits, the behavior of the application can be affected in various ways, mainly in terms of memory consumption and performance.

// Example of inappropriate usage that may lead to excess string allocation
public class ExcessStringPool {
    public static void main(String[] args) {
        for (int i = 0; i < 100000; i++) {
            String str = "String number " + i; // Concatenation will create new instances
        }
    }
}

Causes

• Creating a large number of unique string literals that exceed the available String Pool space.
• Excessive usage of the `new String()` constructor which bypasses the String Pool, leading to more objects in the heap.

Solutions

• Optimize string usage by reusing string literals instead of creating new string objects.
• Use `StringBuilder` or `StringBuffer` for string manipulations instead of excessive string concatenation.

Mistake: Using the `new String()` constructor unnecessarily.

Solution: Always prefer string literals to take advantage of String Pool.

Mistake: Frequent string concatenation within loops, leading to out-of-memory errors.

Solution: Use `StringBuilder` for efficient string concatenation.