How Can I Dynamically Instantiate a Class in Java Using Its Name and Constructor Parameters?

Creating an Instance Dynamically Using Class Name and Constructor Parameters

In certain scenarios, you may encounter the need to create an instance of a class dynamically given its class name and provide parameters to its constructor. This can be achieved using the following approach:

1. Obtain the Class object for the given class name:

   • Utilize the Class.forName() method to load the class based on its fully-qualified name, including the namespace.

2. Retrieve the constructor of the class:

   • Invoke getConstructor() on the Class object to obtain the constructor that matches the desired number and types of parameters.

3. Create an instance of the class using the constructor:

   • Call newInstance() on the constructor, passing the specified parameters as an array of objects.

Here's an example to illustrate this process:

Class<?> clazz = Class.forName("mypackage.MyClass");
Constructor<?> ctor = clazz.getConstructor(String.class);
Object object = ctor.newInstance(new Object[] { "MyAttributeValue" });

Note that this approach requires providing a fully-qualified class name, including any nested classes separated by dollar signs ($). For instance, to create an instance of a nested class, you would use a class name like "foo.Outer$Nested".

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