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ParameterizedType的作用

標籤： Gradle

2015-01-09 18:55 16259人閱讀評論(0)收藏舉報

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public interface ParameterizedType extends Type

subParam.Java

[java] view plain copy

print?

package com.example.test;
public class subParam extends param<myclass, myinvoke> {
public static void main(String[] args) throws Exception{
subParam s = new subParam();
}
}

package com.example.test;

public class subParam extends param<myclass, myinvoke> {
	public static void main(String[] args) throws Exception{
		subParam  s = new subParam();
	}
}

param.java

[java] view plain copy

print?

package com.example.test;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
public class param<T1, T2> {
class A {}
class B extends A {}
private Class<T1> entityClass;
protected param (){
Type type = getClass().getGenericSuperclass();
System.out.println("getClass()==" + getClass());
System.out.println("type = " + type);
Type trueType = ((ParameterizedType)type).getActualTypeArguments()[0];
System.out.println("trueType1 = " + trueType);
trueType = ((ParameterizedType)type).getActualTypeArguments()[1];
System.out.println("trueType2 = " + trueType);
this.entityClass = (Class<T1>)trueType;
B t = new B();
type = t.getClass().getGenericSuperclass();
System.out.println("B is A's super class :" + ((ParameterizedType)type).getActualTypeArguments().length);
}
}

package com.example.test;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

public class param<T1, T2> {
	class A {}
	class B extends A {}
	
	private Class<T1> entityClass;
	protected param (){
		Type type = getClass().getGenericSuperclass();
		System.out.println("getClass()==" + getClass());
		System.out.println("type = " + type);
		Type trueType = ((ParameterizedType)type).getActualTypeArguments()[0];
		System.out.println("trueType1 = " + trueType);
		trueType = ((ParameterizedType)type).getActualTypeArguments()[1];
		System.out.println("trueType2 = " + trueType);
		this.entityClass = (Class<T1>)trueType;
		
		
		B t = new B();
		type = t.getClass().getGenericSuperclass();
	
		System.out.println("B is A's super class :" + ((ParameterizedType)type).getActualTypeArguments().length);
	}
	
}

===================== output =======================

getClass()==class com.example.test.subParam

type = com.example.test.param<com.example.test.myclass, com.example.test.myinvoke>

trueType1 = class com.example.test.myclass

trueType2 = class com.example.test.myinvoke

B is A's super class :0

總結

((ParameterizedType)type).getActualTypeArguments()

是用來的到類的模板參數的類型的？入T1, T2 etc...

返回表示此類型實際類型參數的 Type 對象的數組。