java.lang.Class is a class in java, it represents classes and interfaces in a running Java application.
objects created using newInstance() method will call the default constructor of the class.
Creates a new instance of the class represented by this Class object. The newInstance method of the Class class is used to create an object.
package org.wesome.dsalgo.design.pattern;
public class Apple {
String name = "McIntosh";
public static void main(String[] args) {
try {
Class classObj = Class.forName("org.wesome.dsalgo.design.pattern.Apple");
Apple apple = (Apple) classObj.newInstance();
System.out.println("apple = " + apple.name);
} catch (Exception e) {
e.printStackTrace();
}
}
}
The newInstance method will call the default constructor of the class.
package org.wesome.dsalgo.design.pattern;
public class Apple {
String name = "McIntosh";
public Apple() {
System.out.println("Apple default constructor");
}
public Apple(String name) {
System.out.println("Apple parameterized constructor");
this.name = name;
}
public static void main(String[] args) {
try {
Class classObj = Class.forName("org.wesome.dsalgo.design.pattern.Apple");
Apple apple = (Apple) classObj.newInstance();
System.out.println("apple = " + apple.name);
} catch (Exception e) {
e.printStackTrace();
}
}
}
New Instance with Exception
The newInstance by default calls the default constructor of the class, if the constructor throws an Exception while creating an object, the newInstance will create the object, but if creating an object using new keyword will fail.
package org.wesome.dsalgo.design.pattern;
public class Apple {
String name = "McIntosh";
public Apple() throws Exception {
System.out.println("Apple default constructor");
throw new Exception();
}
public static void main(String[] args) {
try {
Class classObj = Class.forName("org.wesome.dsalgo.design.pattern.Apple");
Apple apple = (Apple) classObj.newInstance();
System.out.println("apple = " + apple.name);
} catch (Exception e) {
e.printStackTrace();
}
}
}
