反射机制 --> Class.newInstance() && Constructor.newInstance()

[airconditionerr]

1. JDK9文档中，Class.newInstance()方法被标识为Deprecated，同时也提到The call clazz.newInstance() can be replaced by clazz.getDeclaredConstructor().newInstance()。
2. The Java™ Tutorials中提到Constructor.newInstance()是首选，原因为：

• Class.newInstance() can only invoke the zero-argument constructor, while Constructor.newInstance() may invoke any constructor, regardless of the number of parameters.（Class.newInstance()方法只能调用无参数的构造方法，而Constructor.newInstance()方法可以调用任意参数数量的构造方法。）
• Class.newInstance() throws any exception thrown by the constructor, regardless of whether it is checked or unchecked. Constructor.newInstance() always wraps the thrown exception with an InvocationTargetException.（Class.newInstance()会抛出任何构造器抛出的受检查异常和不受检查异常；Constructor.newInstance()会将抛出的异常包装在InvocationTargetException中抛出。）
• Class.newInstance() requires that the constructor be visible; Constructor.newInstance() may invoke private constructors under certain circumstances.（Class.newInstance()要求构造方法可见；而Constructor.newInstance()在某些情况下，可以调用私有的构造方法）

Source1:https://docs.oracle.com/javase/tutorial/reflect/member/ctorInstance.html
Source2:https://docs.oracle.com/javase/9/docs/api/java/lang/Class.html

[Snailclimb]

1. JDK9文档中，Class.newInstance()方法被标识为Deprecated，同时也提到The call clazz.newInstance() can be replaced by clazz.getDeclaredConstructor().newInstance()。
2. The Java™ Tutorials中提到Constructor.newInstance()是首选，原因为：

• Class.newInstance() can only invoke the zero-argument constructor, while Constructor.newInstance() may invoke any constructor, regardless of the number of parameters.（Class.newInstance()方法只能调用无参数的构造方法，而Constructor.newInstance()方法可以调用任意参数数量的构造方法。）
• Class.newInstance() throws any exception thrown by the constructor, regardless of whether it is checked or unchecked. Constructor.newInstance() always wraps the thrown exception with an InvocationTargetException.（Class.newInstance()会抛出任何构造器抛出的受检查异常和不受检查异常；Constructor.newInstance()会将抛出的异常包装在InvocationTargetException中抛出。）
• Class.newInstance() requires that the constructor be visible; Constructor.newInstance() may invoke private constructors under certain circumstances.（Class.newInstance()要求构造方法可见；而Constructor.newInstance()在某些情况下，可以调用私有的构造方法）

Source1:https://docs.oracle.com/javase/tutorial/reflect/member/ctorInstance.html Source2:https://docs.oracle.com/javase/9/docs/api/java/lang/Class.html

感谢分享👍

[Przemek270189wav]

1. JDK9文档中，Class.newInstance()方法被标识为Deprecated，同时也提到The call clazz.newInstance() can be replaced by clazz.getDeclaredConstructor().newInstance()。
2. The Java™ Tutorials中提到Constructor.newInstance()是首选，原因为：

• Class.newInstance() can only invoke the zero-argument constructor, while Constructor.newInstance() may invoke any constructor, regardless of the number of parameters.（Class.newInstance()方法只能调用无参数的构造方法，而Constructor.newInstance()方法可以调用任意参数数量的构造方法。）
• Class.newInstance() throws any exception thrown by the constructor, regardless of whether it is checked or unchecked. Constructor.newInstance() always wraps the thrown exception with an InvocationTargetException.（Class.newInstance()会抛出任何构造器抛出的受检查异常和不受检查异常；Constructor.newInstance()会将抛出的异常包装在InvocationTargetException中抛出。）
• Class.newInstance() requires that the constructor be visible; Constructor.newInstance() may invoke private constructors under certain circumstances.（Class.newInstance()要求构造方法可见；而Constructor.newInstance()在某些情况下，可以调用私有的构造方法）

Source1:https://docs.oracle.com/javase/tutorial/reflect/member/ctorInstance.html
Source2:https://docs.oracle.com/javase/9/docs/api/java/lang/Class.html