Example usage for java.lang Class getDeclaredConstructors

Introduction

In this page you can find the example usage for java.lang Class getDeclaredConstructors.

Prototype

@CallerSensitive
public Constructor<?>[] getDeclaredConstructors() throws SecurityException

Source Link

Document

Returns an array of Constructor objects reflecting all the constructors declared by the class represented by this Class object.

Usage

From source file:ReflectionTest.java

public static void printConstructors(Class cl) {
    Constructor[] constructors = cl.getDeclaredConstructors();

    for (int i = 0; i < constructors.length; i++) {
        Constructor c = constructors[i];
        Class[] paramTypes = c.getParameterTypes();
        String name = c.getName();
        System.out.print(Modifier.toString(c.getModifiers()));
        System.out.print(" " + name + "(");
        for (int j = 0; j < paramTypes.length; j++) {
            if (j > 0)
                System.out.print(", ");
            System.out.print(paramTypes[j].getName());
        }/*from  www .java  2 s.  c o m*/
        System.out.println(");");
    }
}

From source file:Main.java

private static Constructor<?> getDefaultConstructor(@NonNull Class<?> cls) {
    final Constructor[] ctors = cls.getDeclaredConstructors();
    Constructor ctor = null;/*  w w w .j a  v  a  2s . co m*/
    for (Constructor ct : ctors) {
        ctor = ct;
        if (ctor.getGenericParameterTypes().length == 0)
            break;
    }
    if (ctor == null)
        throw new IllegalStateException("No default constructor found for " + cls.getName());
    ctor.setAccessible(true);
    return ctor;
}

From source file:ReflectionTest.java

/**
 * Prints all constructors of a class/*from www .  j a  va 2 s .co  m*/
 * @param cl a class
 */
public static void printConstructors(Class cl) {
    Constructor[] constructors = cl.getDeclaredConstructors();

    for (Constructor c : constructors) {
        String name = c.getName();
        System.out.print("   ");
        String modifiers = Modifier.toString(c.getModifiers());
        if (modifiers.length() > 0)
            System.out.print(modifiers + " ");
        System.out.print(name + "(");

        // print parameter types
        Class[] paramTypes = c.getParameterTypes();
        for (int j = 0; j < paramTypes.length; j++) {
            if (j > 0)
                System.out.print(", ");
            System.out.print(paramTypes[j].getName());
        }
        System.out.println(");");
    }
}

From source file:Main.java

public static <T> T newInstance(Class<T> claxx)
        throws IllegalAccessException, InvocationTargetException, InstantiationException {
    Constructor<?>[] cons = claxx.getDeclaredConstructors();
    for (Constructor<?> c : cons) {
        Class[] cls = c.getParameterTypes();
        if (cls.length == 0) {
            c.setAccessible(true);/*from w  ww.  j  av  a  2s  .co m*/
            return (T) c.newInstance();
        } else {
            Object[] objs = new Object[cls.length];
            for (int i = 0; i < cls.length; i++) {
                objs[i] = getDefaultPrimiticeValue(cls[i]);
            }
            c.setAccessible(true);
            return (T) c.newInstance(objs);
        }
    }
    return null;
}

From source file:com.edmunds.autotest.ClassUtil.java

public static Constructor getDefaultConstructor(Class cls) {
    final Constructor[] constructors = cls.getDeclaredConstructors();

    for (Constructor constructor : constructors) {
        if (constructor.getParameterTypes().length == 0) {
            return constructor;
        }/*from ww  w  .  j a va2  s.c  o  m*/
    }

    return null;
}

From source file:org.apache.bval.util.reflection.Reflection.java

/**
 * Convenient point for {@link Privilizing} {@link Class#getDeclaredConstructors()}.
 * @param clazz/*from  w w w . j  a va2s  .com*/
 * @return {@link Constructor} array
 */
public static Constructor<?>[] getDeclaredConstructors(final Class<?> clazz) {
    return clazz.getDeclaredConstructors();
}

From source file:MethodHashing.java

public static Constructor findConstructorByHash(Class clazz, long hash) throws Exception {
    Constructor[] cons = clazz.getDeclaredConstructors();
    for (int i = 0; i < cons.length; i++) {
        if (constructorHash(cons[i]) == hash)
            return cons[i];
    }/*w ww .j  a  va2  s  . com*/
    if (clazz.getSuperclass() != null) {
        return findConstructorByHash(clazz.getSuperclass(), hash);
    }
    return null;
}

From source file:com.edmunds.autotest.ClassUtil.java

public static boolean hasDefaultConstructor(Class cls) {
    boolean defaultConstructor = false;

    final Constructor[] constructors = cls.getDeclaredConstructors();

    for (Constructor constructor : constructors) {
        if (constructor.getParameterTypes().length == 0) {
            defaultConstructor = true;/*from  w  w w. j  a va2s .c o m*/
            break;
        }
    }
    return defaultConstructor;
}

From source file:org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.GroovyCallSiteSelector.java

public static @CheckForNull Constructor<?> constructor(@Nonnull Class<?> receiver, @Nonnull Object[] args) {
    for (Constructor<?> c : receiver.getDeclaredConstructors()) {
        if (matches(c.getParameterTypes(), args)) {
            return c;
        }//from w w w  . ja v a  2s.  c om
    }
    return null;
}

From source file:com.github.tomakehurst.wiremock.matching.StringValuePatternJsonDeserializer.java

@SuppressWarnings("unchecked")
private static Constructor<? extends StringValuePattern> findConstructor(
        Class<? extends StringValuePattern> clazz) {
    Optional<Constructor<?>> optionalConstructor = tryFind(asList(clazz.getDeclaredConstructors()),
            new Predicate<Constructor<?>>() {
                @Override//from www .  ja  v  a 2 s  . c om
                public boolean apply(Constructor<?> input) {
                    return input.getParameterTypes().length == 1
                            && input.getGenericParameterTypes()[0].equals(String.class);
                }
            });

    if (!optionalConstructor.isPresent()) {
        throw new IllegalStateException(
                "Constructor for " + clazz.getSimpleName() + " must have a single string argument constructor");
    }

    return (Constructor<? extends StringValuePattern>) optionalConstructor.get();
}