Java Utililty Methods Class New Instance

List of utility methods to do Class New Instance

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Description

The list of methods to do Class New Instance are organized into topic(s).

Method

ObjectnewInstance(Class klass)
new Instance 
try {
    return klass.newInstance();
} catch (Exception e) {
    throw new RuntimeException(e);
ObjectnewInstance(Class targetClass)
new Instance 
Constructor ctor = targetClass.getDeclaredConstructor(EMPTY_CLASS_ARRAY);
ctor.setAccessible(true);
return ctor.newInstance(EMPTY_OBJECT_ARRAY);
ObjectnewInstance(Class cl, Object[] args)
Create an instance of a class cl from constructor with arguments args, even if the constructor is a private constructor. 
Class<? extends Object>[] classArray = new Class<?>[args == null ? 0 : args.length];
for (int i = 0; i < args.length; i++) {
    classArray[i] = builtInMap.get(args[i].getClass()) == null ? args[i].getClass()
            : builtInMap.get(args[i].getClass());
Constructor<? extends Object> constructor = cl.getDeclaredConstructor(classArray);
constructor.setAccessible(true);
return constructor.newInstance(args);
...
TnewInstance(Class clazz)
new Instance 
try {
    return clazz.newInstance();
} catch (Exception e) {
    throw new RuntimeException("Cant create bean", e);
T[]newInstance(Class componentType, int length)
Creates and returns an array of the given type and size. 
return (T[]) Array.newInstance(componentType, length);
ObjectnewInstance(Class classZ)
new Instance 
Object instance;
try {
    instance = classZ.newInstance();
} catch (InstantiationException | IllegalAccessException e) {
    logger.error("new instance failure", e);
    throw new RuntimeException(e);
return instance;
...
ObjectnewInstance(Class clazz)
new Instance 
if (clazz.isPrimitive()) {
    return primitiveToDefault.get(clazz);
} else if (Calendar.class.isAssignableFrom(clazz)) {
    return Calendar.getInstance();
} else if (clazz.isArray()) {
    Class<?> ct = clazz.getComponentType();
    Object a = Array.newInstance(ct, 1);
    Array.set(a, 0, newInstance(ct));
...
ObjectnewInstance(Class clazz)
new Instance 
try {
    return clazz.newInstance();
} catch (InstantiationException e) {
    throw new IllegalStateException("Failed to instantiate the class: " + clazz, e);
} catch (IllegalAccessException e) {
    throw new IllegalStateException("Illegal access to the constructor of the class: " + clazz, e);
ObjectnewInstance(Class clazz)
Tries to invoke Foo.getInstance() if the method (public+static) getInstance() is there; If not, it creates a new instance via reflection. 
Object o = getInstance(clazz);
return o == null ? clazz.newInstance() : o;
TnewInstance(Class clazz)
new Instance 
try {
    return (T) clazz.newInstance();
} catch (InstantiationException e) {
    throw new RuntimeException(e);
} catch (IllegalAccessException e) {
    throw new RuntimeException(e);