[英]using JAVA reflection to execute the class
因此,這是帶有內部聲明的私有內部類和私有屬性的類。 我需要使用Java反射在主函數中編寫測試程序來執行此類。
public class Outter {
private Inner in;
public Outter(){
in = new Inner();
}
private class Inner{
private void test(){
System.out.println("test");
}
}
}
這是測試代碼: 我的問題在語句后列出。
public class Test
{
public static void main(String[] args) throws Exception
{
// 1. How do i create a Class type for Inner class since its modifier
// is private, if I am going to need .setAccessible() then how do i
// use it?
Class outter1 = Outter.class;
// 2. How do I pass parameters of type Inner to the Class object?
Constructor con = outter1.getConstructor(new Class[]{int.class});
// 3. Like this?
Field fields = outter1.getField("test");
fields.setAccessible(true);
// 4. Well I am lost what is the logic route for me to follow when
// using java reflection to execute a class like this!
Object temp = outter1.newInstance();
Outter outter = (Outter)temp;
System.out.println(fields.get(outter));
}
}
這是您要執行的操作的獨立示例。
您正在運行的代碼
try {
// gets the "in" field
Field f = Outer.class.getDeclaredField("in");
// sets it accessible as it's private
f.setAccessible(true);
// gets an instance of the Inner class by getting the instance of the
// "in" field from an instance of the Outer class - we know "in" is
// initialized in the no-args constructor
Object o = Object o = f.get(Outer.class.newInstance());
// gets the "execute" method
Method m = o.getClass().getDeclaredMethod("test", (Class<?>[])null);
// sets it accessible to this context
m.setAccessible(true);
// invokes the method
m.invoke(o, (Object[])null);
}
// TODO better handling
catch (Throwable t) {
t.printStackTrace();
}
班級(內部/外部)...
public class Outer {
private Inner in;
public Outer() {
in = new Inner();
}
private class Inner {
private void test() {
System.out.println("test");
}
}
}
輸出量
test
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