Does Using Reflection for Object Instantiation in Java Significantly Impact Performance?

Performance Implications of Object Instantiation Using Reflection in Java

When creating an object in Java, one may wonder if using reflection, as opposed to invoking the class constructor directly, has noticeable performance impacts.

Performance Penalty

The answer is a definitive yes. Reflection incurs a significant performance overhead compared to traditional constructor calls.

Java's documentation explicitly states that "reflection involves types that are dynamically resolved, certain Java virtual machine optimizations cannot be performed" and that "reflective operations have slower performance than their non-reflective counterparts."

Benchmarks

To illustrate this, a simple test was conducted. It created 1,000,000 objects using both reflection and constructor calls and measured the execution time in milliseconds. The results revealed a stark difference:

• Constructor calls: 35 ms
• Reflection: 465 ms

Implications for Performance-Sensitive Applications

This performance penalty implies that reflection should be avoided in code sections called frequently in applications where performance is critical.

Even if the lookup operation is optimized to be performed only once, there is still a performance hit associated with object instantiation using reflection.

Therefore, it is recommended to utilize constructor calls for object creation unless there are specific requirements or architectural constraints that necessitate the use of reflection.

The above is the detailed content of Does Using Reflection for Object Instantiation in Java Significantly Impact Performance?. For more information, please follow other related articles on the PHP Chinese website!