import java.lang.reflect.Constructor;  import java.lang.reflect.Field;  import java.lang.reflect.Method;  import android.os.Bundle;  import android.app.Activity;  /**  * Demo描述:  * Android中Java反射技术的使用示例  * 在Java中描述字节码文件(xxx.class)的类叫Class  * 反射的过程可视为剖析Class的过程  */  public class MainActivity extends Activity {      @Override      protected void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          setContentView(R.layout.main);          init();      }      private void init(){          try {              /**              * 1 反射出无参的构造方法并得到对象              * 注意:              *      1 在Class.forName()中应该传入含有包名的类全名              *      2 newInstance()方法的本质是调用类的无参Public构造方法              */              String className1="cn.testreflect.Worker";              Class clazz1=Class.forName(className1);              Object object1=clazz1.newInstance();              System.out.println("object1.toString()="+object1.toString());                            /**              * 2 反射出带参数的构造方法并得到对象              */              String className2="cn.testreflect.Worker";              Class clazz2=Class.forName(className2);              Constructor constructor1=clazz2.getConstructor(int.class,String.class);              Object object2=constructor1.newInstance(18,"小明");              System.out.println("object2.toString()="+object2.toString());                            /**              * 3 获取类的私有字段              * 注意:              *      获取共有字段应调用clazz3.getField(name)方法              */              String className3="cn.testreflect.Worker";              Class clazz3=Class.forName(className3);              Field ageField1=clazz3.getDeclaredField("age");              System.out.println("ageField1="+ageField1);                            /**              * 4 获取和更改某个对象的私有字段              *   即模拟get()和set()方法              */              String className4="cn.testreflect.Worker";              Class clazz4=Class.forName(className4);              Field ageField2=clazz4.getDeclaredField("age");              Object object4=constructor1.newInstance(18,"小明");              //取消访问私有字段的合法性检查              ageField2.setAccessible(true);              //获取对象的私有字段              Object ageObject4=ageField2.get(object4);              System.out.println("ageObject4="+ageObject4);                            //再更改对象的私有字段的值              ageField2.set(object4, 9527);              //重新获得              Object ageObject5=ageField2.get(object4);              System.out.println("ageObject5="+ageObject5);                            /**              * 5 调用对象的带参数的方法              */              String className5="cn.testreflect.Worker";              Class clazz5=Class.forName(className5);              Method method=clazz5.getMethod("printMessage", String.class,int.class,int.class);              Object object5=clazz5.newInstance();              method.invoke(object5, "周星星",50,9527);                                      } catch (Exception e) {              System.out.println(e.toString());          }            }

public class Worker {          private int age;          private String name;          public Worker() {              super();              System.out.println("---> public Worker(){ }");          }          public Worker(int age, String name) {              super();              this.age = age;              this.name = name;              System.out.println("---> public Worker(int age, String name){ }");          }          public int getAge() {              return age;          }          public void setAge(int age) {              this.age = age;          }          public String getName() {              return name;          }          public void setName(String name) {              this.name = name;          }          @Override          public String toString() {              return "Worker [age=" + age + ", name=" + name + "]";          }                    public void printMessage(String name,int age,int salary){              System.out.println("name="+name+",age="+age+",salary="+salary);          }                }

main.xml