反射获取全部成员变量，并获取对应的值

爱被打了一巴掌 2022-05-21 11:38 234阅读 0赞

直接代码Kotlin、java 两种

准备实体类

class UserInfo(var name: String, var nickname: String) {
      fun loginValue (){
        System.err.print("name = $name nickname = $nickname")
      }
    }

public class UserInfoJ {
      private String name;
      private String nickname;
    
      public UserInfoJ(String name, String nickname) {
        this.name = name;
        this.nickname = nickname;
      }
    
      public String getName() {
        return name;
      }
    
      public void setName(String name) {
        this.name = name;
      }
    
      public String getNickname() {
        return nickname;
      }
    
      public void setNickname(String nickname) {
        this.nickname = nickname;
      }
    }

创建工具类

public class TestUtilJ {
      public void reflex(Object obj){
        Class<?> aClass = obj.getClass();
        // aClass.getFields() 获取 public 类型的成员
        Field[] declaredFields = aClass.getDeclaredFields(); //获取所有成员包含 private
        Method[] methods = aClass.getMethods();
        for (Method mt:
        methods) {
          String mn = mt.getName();
          Object dv = mt.getDefaultValue();
          String returnType = mt.getReturnType().getName();
          System.err.println("方法名称：" + mn + "    默认值：" + dv + "    返回类型：" + returnType);
        }
        for (Field field:
        declaredFields) {
          try {
            field.setAccessible(true);
            String fn = field.getName();
            Log.e(getClass().getSimpleName(), "属性名称：" + fn + "   field.get(obj)= " + field.get(obj));
          } catch (IllegalAccessException e) {
            e.printStackTrace();
          }
        }
      }
    }

需要注意 aClass.fields 无法获取 kotlin 创建的成员

class TestUtil {
      fun reflex(obj: Any) {
        val aClass = obj.javaClass //    aClass.fields 无法获取 kotlin 创建的成员
        val declaredFields = aClass.declaredFields val methods = aClass.methods for (mt in methods) {
          val mn = mt.name val dv = mt.defaultValue val returnType = mt.returnType.name System.err.println("方法名称：$mn    默认值：$dv    返回类型：$returnType")
        }
        for (field in declaredFields) {
          try {
            field.isAccessible = true // 如果不设置不能获对应的值
            val fn = field.name Log.e(javaClass.simpleName, "属性名称：$fn  field.get(obj)= ${
       field.get(obj)}")
          } catch (e: IllegalAccessException) {
            e.printStackTrace()
          }
        }
      }
    }

MainActivity 暂未提供 Java 版本，不懂得小伙伴可自己调用

class MainActivity : AppCompatActivity() {
    
      override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        var userInfoC = UserInfoJ("勤和", "测试")
        TestUtilJ().reflex(userInfoC)
        var userInfo = UserInfo("kotlin", "测试反射")
        var tUtil = TestUtil()
        tUtil.reflex(userInfo)
      }
    }