通过Class的getConstructors 可以取得类的所有构造函数定义。
[
java] Class aClass = ...//obtain class object
Constructor[] constructors = aClass.getConstructors();
Class aClass = ...//obtain class object
Constructor[] constructors = aClass.getConstructors();
如果知道构造函数的参数定义,可以直接取得对应的构造函数,如:
[
java]
Class aClass = ...//obtain class object
Constructor constructor =
aClass.getConstructor(new Class[]{String.class});
Class aClass = ...//obtain class object
Constructor constructor =
aClass.getConstructor(new Class[]{String.class});
如果Reflection API找不到对应的构造函数,则抛出NoSuchMethodException异常。
1. 获取构造函数的参数定义
[
java]
Class[] parameterTypes = constructor.getParameterTypes();
Class[] parameterTypes = constructor.getParameterTypes();
2. 使用构造函数定义创建实例
[
java]
//get constructor that takes a String as argument
Constructor constructor = MyObject.class.getConstructor(String.class);
MyObject myObject = (MyObject)
constructor.newInstance("constructor-arg1");
//get constructor that takes a String as argument
Constructor constructor = MyObject.class.getConstructor(String.class);
MyObject myObject = (MyObject)
constructor.newInstance("constructor-arg1");
newInstance 的参数可以选,调用时参数个数必须和对应的Constructor 定义的参数个数一致。
摘自 引路蜂移动
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