Java反射Reflectionでクラス属性、メソッド、構築メソッド、および呼び出しクラスメソッドを取得してオブジェクト属性を変更するテスト
15665 ワード
1 package com.li.test;
2 /**
3 * User
4 * @author Administrator
5 */
6 public class User {
7
8 /**
9 * name
10 */
11 private String name;//name
12 private int age;//age
13
14 public User() {
15 }
16 public User(String name,int age) {
17 this.name = name;
18 this.age = age;
19 }
20
21 public String getName() {
22 return name;
23 }
24
25 public void setName(String name) {
26 this.name = name;
27 }
28
29 public int getAge() {
30 return age;
31 }
32
33 public void setAge(int age) {
34 this.age = age;
35 }
36 } 1 package com.li.test;
2
3 import java.lang.reflect.Constructor;
4 import java.lang.reflect.Field;
5 import java.lang.reflect.InvocationTargetException;
6 import java.lang.reflect.Method;
7
8 /**
9 * java Reflection 、 、
10 *
11 * @author Administrator
12 *
13 */
14 public class TestReflect {
15
16 /**
17 * @param args
18 */
19 public static void main(String[] args) {
20 //
21 Field[] field = User.class.getDeclaredFields();
22 System.out.println("User ----begin-----");
23 for (int i = 0; i < field.length; i++) {
24 System.out.println(field[i].getName());
25 }
26 System.out.println("User ----end-----");
27 //
28 Method method[] = User.class.getDeclaredMethods();
29 System.out.println("User ----begin-----");
30 for (int i = 0; i < method.length; i++) {
31 System.out.println(method[i].getName());
32 }
33 System.out.println("User ----end-----");
34 //
35 Constructor constructor[] = User.class.getDeclaredConstructors();
36 System.out.println("User ----begin-----");
37 for (int i = 0; i < constructor.length; i++) {
38 System.out.println(constructor[i]);
39 }
40 System.out.println("User ----end-----");
41 //
42 User user1 = new User("A", 1);
43 System.out.println("begin " + user1.getName() + user1.getAge());
44 Field fieldName = null;
45 try {
46 fieldName = User.class.getDeclaredField("name");
47 } catch (SecurityException e1) {
48 // TODO Auto-generated catch block
49 e1.printStackTrace();
50 } catch (NoSuchFieldException e1) {
51 // TODO Auto-generated catch block
52 e1.printStackTrace();
53 }
54 Method setNameMethod = null;
55 Method getNameMethod = null;
56 Object name = null;
57 try {
58 setNameMethod = user1.getClass().getDeclaredMethod("setName",new Class[]{fieldName.getType()});
59 getNameMethod = user1.getClass().getDeclaredMethod("getName",new Class[]{});
60 } catch (SecurityException e) {
61 e.printStackTrace();
62 } catch (NoSuchMethodException e) {
63 e.printStackTrace();
64 }
65 try {
66 setNameMethod.invoke(user1, new Object[]{"B"});
67 name = getNameMethod.invoke(user1, new Class[]{});
68
69 } catch (IllegalArgumentException e) {
70 // TODO Auto-generated catch block
71 e.printStackTrace();
72 } catch (IllegalAccessException e) {
73 // TODO Auto-generated catch block
74 e.printStackTrace();
75 } catch (InvocationTargetException e) {
76 // TODO Auto-generated catch block
77 e.printStackTrace();
78 }
79
80 System.out.println("end " + user1.getName() + user1.getAge());
81 System.out.println("end " + (String)name);
82 }
83
84 }コンソール出力は次のとおりです.
Userクラス属性------begin------nameageUserクラス属性------end------Userクラスメソッド------begin------get AgesetAgegetNamesetNameUserクラスメソッド------end------Userクラス構造メソッド------begin------public com.li.test.User()public com.li.test.User(java.lang.String,int)Userクラス構築方法------end------begin A 1 end B 1 end B