21 }
22 }
23 }
24 }
25 /* 输出结果如下(由于输出较长，这里只是给出有代表性的输出)：
26 ... ...
27 public void java.util.ArrayList.add(int,E)
28 ReturnType: void
29 GenericReturnType: void
30 ParameterType: int
31 GenericParameterType: int
32 ParameterType: class java.lang.Object
33 GenericParameterType: E
34 ... ...
35 public
36 ReturnType: class [Ljava.lang.Object;
37 GenericReturnType: T[]
38 ParameterType: class [Ljava.lang.Object;
39 GenericParameterType: T[]
40 ... ...
41 */
4) 输出对象域字段的类型信息：
1 public class MyTest
2 public String name = "Alice";
3 public List
4 public T val;
5
6 public static void main(String args[]) throws Exception {
7 Class< > c = Class.forName("MyTest");
8 for (Field f : c.getFields()) {
9 //getType和getGenericType之间的差异和上面用到的
10 //getReturnType和getGenericReturnType之间的差别相同
11 System.out.format("Type: %s%n", f.getType());
12 System.out.format("GenericType: %s%n", f.getGenericType());
13 }
14 }
15 }
16 /* 输出结果如下：
17 Type: class java.lang.String
18 GenericType: class java.lang.String
19 Type: interface java.util.List
20 GenericType: java.util.List
21 Type: class java.lang.Object
22 GenericType: T
23 */
5. 枚举的反射：
1) 获取枚举的常量列表：
1 import static java.lang.System.out;
2 public class MyTest {
3 public static void main(String args[]) throws Exception {
4 //判断该类是否为枚举
5 if (!Eon.class.isEnum())
6 return;
7 Class< > c = Eon.class;
8 out.format("Enum name: %s%nEnum constants: %s%n", c.getName(),
9 Arrays.asList(c.getEnumConstants()));
10 Eon[] vs = Eon.values();
11 for (Eon e : vs) {
12 out.println("The name is " + e.name() + "\tThe ordinal is " + e.ordinal());
13 }
14 }
15 }
16
17 enum Eon {
18 HADEAN, ARCHAEAN, PROTEROZOIC, PHANEROZOIC
19 }
20 /* 输出结果如下：
21 Enum name: Eon
22 Enum constants: [HADEAN, ARCHAEAN, PROTEROZOIC, PHANEROZOIC]
23 The name is HADEAN The ordinal is 0
24 The name is ARCHAEAN The ordinal is 1
25 The name is PROTEROZOIC The ordinal is 2
26 The name is PHANEROZOIC The ordinal is 3
27 */
6. 域方法的反射：
1) 通过类构造器的反射对象构造新实例：
1 public static void main(String args[]) throws Exception {
2 //根据构造函数的参数列表获取Point类的带有该参数列表的构造函数的反射类
3 //该构造函数的原型为Point(int x,int y);
4 Constructor
5 int.class, int.class });
6 //由于参数必须是Object的数组表示，因此对于Point构造的两个
7 //int参数，只能使用他们的包括类Integer.
8 Point obj = (Point) con.newInstance(new Object[] {
9