本教程操作环境：windows7系统、java10版，DELL G3电脑。
1、过程
（1）测试属性类型
（2）打印type与generic type的区别
（3）测试参数类型
（4）测试返回值类型
2、实例
public class Client {
private Map objectMap;
public void test(Map map, String string) {
}
public Map test() {
return null;
}
/**
* 测试属性类型
*
* @throws NoSuchFieldException
*/
@Test
public void testFieldType() throws NoSuchFieldException {
Field field = Client.class.getDeclaredField("objectMap");
Type gType = field.getGenericType();
// 打印type与generic type的区别
System.out.println(field.getType());
System.out.println(gType);
System.out.println("**************");
if (gType instanceof ParameterizedType) {
ParameterizedType pType = (ParameterizedType) gType;
Type[] types = pType.getActualTypeArguments();
for (Type type : types) {
System.out.println(type.toString());
}
}
}
/**
* 测试参数类型
*
* @throws NoSuchMethodException
*/
@Test
public void testParamType() throws NoSuchMethodException {
Method testMethod = Client.class.getMethod("test", Map.class, String.class);
Type[] parameterTypes = testMethod.getGenericParameterTypes();
for (Type type : parameterTypes) {
System.out.println("type -> " + type);
if (type instanceof ParameterizedType) {
Type[] actualTypes = ((ParameterizedType) type).getActualTypeArguments();
for (Type actualType : actualTypes) {
System.out.println("tactual type -> " + actualType);
}
}
}
}
/**
* 测试返回值类型
*
* @throws NoSuchMethodException
*/
@Test
public void testReturnType() throws NoSuchMethodException {
Method testMethod = Client.class.getMethod("test");
Type returnType = testMethod.getGenericReturnType();
System.out.println("return type -> " + returnType);
if (returnType instanceof ParameterizedType) {
Type[] actualTypes = ((ParameterizedType) returnType).getActualTypeArguments();
for (Type actualType : actualTypes) {
System.out.println("tactual type -> " + actualType);
}
}
}
}
以上就是java使用ParameterizedType实现泛型的方法，希望能对大家有所帮助。更多Java学习指路：Java基础
