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Java reflection get public constructor


The java.lang.Class provides the methods to examine the runtime properties of the object including its members and type information. For every type of object, the JVM instantiates an immutable instance of java.lang.Class. Using reflection, we can get the metadata of a class at run time.

The getConstructor() method is used to get the public constructor in java.

Example

TestClass.java

package com.codesjava;
 
public class TestClass {
	private String message;
 
	public TestClass(String message){
		this.message = message;
	}
 
	private void display(){
		System.out.println(message);
	}
}

ReflectionTest.java

package com.codesjava;
 
import java.lang.reflect.Constructor;
import java.util.Arrays;
 
public class ReflectionTest {
	public static void main(String args[]){
		try {
			Class c=Class.forName("com.codesjava.TestClass");  
			Constructor<?> constructor = c.getConstructor(String.class);
			System.out.println(Arrays.toString(constructor.getParameterTypes()));
		} catch (Exception e) {
			e.printStackTrace();
		}  
	}
}

Output

[class java.lang.String]


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