List listUser = new ArrayList();
Type genType = listUser.getClass().getClass().getGenericSuperclass();
Class templatClazz = null;
if(ParameterizedType.class.isInstance(genType)
{
//无法获取到User类，或者可能获取到错误的类型，如果有同名且不带包名的泛型存在
ParameterizedType parameterizedType = (ParameterizedType) genType;
templatClazz = (Class) parameterizedType.getActualTypeArguments()[0];
}
那么，如何才能获取到泛型的类型
①.必须具有真实类型的存在
②.泛型的类型是明确的如(List是明确的，List是不明确的)
满足以上两点，我们就可以获取泛型的类型了
1.通过继承方式，明确类型，然后获取泛型类
public abstract class JdbcDaoSupport {
protected JdbcDaoSupport() {
}
public Class getTempalteType()
{
Class clazz = (Class) ((ParameterizedType) getClass()
.getGenericSuperclass()).getActualTypeArguments()[0];
return clazz;
}
}
public class UserDao extends JdbcDaoSupport {
}
public class Test{
public static void main(String[] args)
{
UserDao dao = new UserDao();
Class clazz = dao.getTemplateType();
System.out.println(clazz.getName()); //输出 xxx.xxx.User
}
}
2.获取类属性的泛型类型
public class Test extends ClassA {
private List list;
private Map map;
/***
* 获取List中的泛型
*/
public static void testList() throws NoSuchFieldException, SecurityException {
Type t = Test.class.getDeclaredField("list").getGenericType();
if (ParameterizedType.class.isAssignableFrom(t.getClass())) {
for (Type t1 : ((ParameterizedType) t).getActualTypeArguments()) {
System.out.print(t1 + ",");
}
System.out.println();
}
}
/***
* 获取Map中的泛型
*/
public static void testMap() throws NoSuchFieldException, SecurityException {
Type t = Test.class.getDeclaredField("map").getGenericType();
if (ParameterizedType.class.isAssignableFrom(t.getClass())) {
for (Type t1 : ((ParameterizedType) t).getActualTypeArguments()) {
System.out.print(t1 + ",");
}
System.out.println();
}
}
public static void main(String args[]) throws Exception {
System.out.println(">>>>>>>>>>>testList>>>>>>>>>>>");
testList();
System.out.println("<<<<<<<<<<>>>>>>>>>>testMap>>>>>>>>>>>");
testMap();
System.out.println("<<<<<<<<<<>>>>>>>>>>testClassA>>>>>>>>>>>");
new Test().testClassA();
System.out.println("<<<<<<<<<<
3.获取局部变量的泛型的类型
List lst = new ArrayList(){};
Type genType = listUser.getClass().getClass().getGenericSuperclass();
Class templatClazz = null;
if(ParameterizedType.class.isInstance(genType)
{
ParameterizedType parameterizedType = (ParameterizedType) genType;
templatClazz = (Class) parameterizedType.getActualTypeArguments()[0];
}
class JsonToObjectUtil {
public static T jsonToObject(Class clz,List jsonList){
Type genType = clz.getClass().getGenericSuperclass();
Class templatClazz = null;
if(ParameterizedType.class.isInstance(genType));
{
ParameterizedType parameterizedType = (ParameterizedType) genType;
templatClazz = (Class) parameterizedType.getActualTypeArguments()[0];
}
List
