这就是我如何使用动态构造函数args list创建Class clazz的实例。

final Constructor constructor = clazz.getConstructors()[0];
final int constructorArgsCount = constructor.getParameterCount();
if (constructorArgsCount > 0) {
    final Object[] constructorArgs = new Object[constructorArgsCount];
    int i = 0;
    for (Class parameterClass : constructor.getParameterTypes()) {
        Object dummyParameterValue = getDummyValue(Class.forName(parameterClass.getTypeName()), null);
        constructorArgs[i++] = dummyParameterValue;
    }
    instance = constructor.newInstance(constructorArgs);
} else {
    instance = clazz.newInstance();
}

这就是getDummyValue()方法的样子，

private static Object getDummyValue(final Class clazz, final Field field) throws Exception {
    if (int.class.equals(clazz) || Integer.class.equals(clazz)) {
        return DUMMY_INT;
    } else if (String.class.equals(clazz)) {
        return DUMMY_STRING;
    } else if (boolean.class.equals(clazz) || Boolean.class.equals(clazz)) {
        return DUMMY_BOOL;
    } else if (List.class.equals(clazz)) {
        Class fieldClassGeneric = Class.forName(((ParameterizedType) field.getGenericType()).getActualTypeArguments()[0].getTypeName());
        return List.of(getDummyValue(fieldClassGeneric, null));
    } else if (USER_DEFINED_CLASSES.contains(clazz.getSimpleName())) {
        return createClassInstance(clazz);
    } else {
         throw new Exception("Dummy value for class type not defined - " + clazz.getName();
    }
}

我觉得这正是你想要的 http://da2i.univ-lille1.fr/doc/tutorial-java/reflect/object/arg.html

虽然它看起来是一条死线，但有人可能会发现它有用

不要使用Class.newInstance();为什么Class.newInstance()是邪恶的?

像其他答案说，使用Constructor.newInstance()代替。

按照以下步骤调用参数化构造函数。

通过在Class[]中传递类型获取带参数类型的构造函数 用于类的getDeclaredConstructor方法 通过在Object[]中传递值创建构造函数实例 构造函数的newInstance方法

示例代码:

import java.lang.reflect.*;

class NewInstanceWithReflection{
    public NewInstanceWithReflection(){
        System.out.println("Default constructor");
    }
    public NewInstanceWithReflection( String a){
        System.out.println("Constructor :String => "+a);
    }
    public static void main(String args[]) throws Exception {

        NewInstanceWithReflection object = (NewInstanceWithReflection)Class.forName("NewInstanceWithReflection").newInstance();
        Constructor constructor = NewInstanceWithReflection.class.getDeclaredConstructor( new Class[] {String.class});
        NewInstanceWithReflection object1 = (NewInstanceWithReflection)constructor.newInstance(new Object[]{"StackOverFlow"});

    }
}

输出:

java NewInstanceWithReflection
Default constructor
Constructor :String => StackOverFlow

MyClass.class.getDeclaredConstructor(String.class).newInstance("HERESMYARG");

or

obj.getClass().getDeclaredConstructor(String.class).newInstance("HERESMYARG");

这就是我如何使用动态构造函数args list创建Class clazz的实例。

final Constructor constructor = clazz.getConstructors()[0];
final int constructorArgsCount = constructor.getParameterCount();
if (constructorArgsCount > 0) {
    final Object[] constructorArgs = new Object[constructorArgsCount];
    int i = 0;
    for (Class parameterClass : constructor.getParameterTypes()) {
        Object dummyParameterValue = getDummyValue(Class.forName(parameterClass.getTypeName()), null);
        constructorArgs[i++] = dummyParameterValue;
    }
    instance = constructor.newInstance(constructorArgs);
} else {
    instance = clazz.newInstance();
}

这就是getDummyValue()方法的样子，

private static Object getDummyValue(final Class clazz, final Field field) throws Exception {
    if (int.class.equals(clazz) || Integer.class.equals(clazz)) {
        return DUMMY_INT;
    } else if (String.class.equals(clazz)) {
        return DUMMY_STRING;
    } else if (boolean.class.equals(clazz) || Boolean.class.equals(clazz)) {
        return DUMMY_BOOL;
    } else if (List.class.equals(clazz)) {
        Class fieldClassGeneric = Class.forName(((ParameterizedType) field.getGenericType()).getActualTypeArguments()[0].getTypeName());
        return List.of(getDummyValue(fieldClassGeneric, null));
    } else if (USER_DEFINED_CLASSES.contains(clazz.getSimpleName())) {
        return createClassInstance(clazz);
    } else {
         throw new Exception("Dummy value for class type not defined - " + clazz.getName();
    }
}