[英]Invoke private method with interface as argument
I've been attempting to invoke a private method whose argument is a parameter and I can't quite seem to get it right. 我一直在尝试调用一个参数为参数的私有方法,但似乎不太正确。
Here's kind of how the code looks so far: 到目前为止,代码看起来是这样的:
public class TestClass {
public TestClass(){
}
private void simpleMethod( Map<String, Integer> testMap) {
//code logic
}
}
Then I attempt to use this to invoke the private method: 然后,我尝试使用它来调用私有方法:
//instance I would like to invoke simpleMethod on
TestClass testClassObject = new TestClass();
//Hashmap
Map <String, Integer> testMap = new HashMap <String, Integer>();
//method I want to invoke
Method simpleMethod = TestClass.class.getDeclaredMethod("simpleMethod", Map.class);
simpleMethod.setAccessible(true);
simpleMethod.invoke(testClassObject, testMap); //Throws an IllegalArgumentException
As you can see, it throws an IllegalArgumentException. 如您所见,它将引发IllegalArgumentException。 I've attempted to cast the hashmap back to a map, but that didn't work. 我试图将哈希图重新投射回地图,但这没有用。
What am I doing wrong? 我究竟做错了什么?
I just tested it, and your code works 100% fine here, when I instantiate your TestClass object like: 我刚刚对其进行了测试,当我实例化您的TestClass对象时,您的代码在这里可以100%正常工作:
TestClass testClassObject = new TestClass();
Maybe you're using different imports (eg a different Map than java.util.Map
)? 也许您使用的是不同的导入(例如,与java.util.Map
不同的Map)?
Everything works just as expected and prints "simpleMethod invoked". 一切都按预期工作,并显示“ simpleMethod invoked”。
TestClass.java TestClass.java
import java.util.Map;
public class TestClass {
public TestClass() {
}
private void simpleMethod(Map<String, Integer> testMap) {
System.err.println("simpleMethod invoked");
}
}
Caller.java Caller.java
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
public class Caller {
public static void main(String[] args) throws IllegalArgumentException,
IllegalAccessException, InvocationTargetException,
SecurityException, NoSuchMethodException {
// Hashmap
Map<String, Integer> testMap = new HashMap<String, Integer>();
// method I want to invoke
Method simpleMethod = TestClass.class.getDeclaredMethod("simpleMethod",
Map.class);
simpleMethod.setAccessible(true);
TestClass testClassObject = new TestClass();
simpleMethod.invoke(testClassObject, testMap);
}
}
The code as posted works fine for me. 发布的代码对我来说很好。 Tweaking the code a little, I get an IllegalArgumentException when testMap is null. 稍微调整一下代码,当testMap为null时,我得到一个IllegalArgumentException。 "wrong number of arguments". “参数数量错误”。
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