Android插件化开发基础之Java反射机制研究（2）-阿里云开发者社区

Android插件化开发基础之Java反射机制研究（2）

2021-12-15 120

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简介： Android插件化开发基础之Java反射机制研究（2）

十一、操作数组

int tmp[] = {1,2,3};

Class<?> c = tmp.getClass().getComponentType();

Array.getLength(tmp); //tmp数组的长度

c.getName(); //获得数组类型名称

Array.get(Object obj,int index); //获得obj数组的index索引的数值

Array.set(Object obj,int index,VALUE); //设置obj数组的index索引的数值为value；

Object obj = Array.newInstance(c,length); //c为数组的类型，length为数组的长度；obj为返回的数组对象；

import java.lang.reflect.*;  
public class GetMethodDemo01{  
    public static void main(String args[])throws Exception{  
        Class<?> c1 = Class.forName("Person");  
        Method m = c1.getMethod("sayHello");  
        m.invoke(c1.newInstance());  
        Method m2 = c1.getMethod("sayHello2",String.class,int.class);  
        String str = (String)m2.invoke(c1.newInstance(),"xiazdong",123);  
        System.out.println(str);  
        Field nameField = c1.getDeclaredField("name");  
        Field ageField = c1.getDeclaredField("age");  
        nameField.setAccessible(true);  
        ageField.setAccessible(true);  
        Person obj = (Person)c1.newInstance();  
        obj.setName("xzdong");  
        obj.setAge(12);  
        System.out.println(nameField.get(obj));  
        System.out.println(ageField.get(obj));  
        Method setName = c1.getMethod("setName",String.class);  
        setName.invoke(obj,"changed");  
        Method getName = c1.getMethod("getName");  
        System.out.println(getName.invoke(obj));  
        int tmp[] = {1,2,3};  
        Class<?> c3 = tmp.getClass().getComponentType();  
        System.out.println(c3.getName());  
        System.out.println("第一个数："+Array.get(tmp,0));  
        Array.set(tmp,0,5);  
        System.out.println("第一个数："+Array.get(tmp,0));  
        Object arr = Array.newInstance(c3,5);  
        System.arraycopy(tmp,0,arr,0,Array.getLength(tmp));  
        System.out.println(Array.get(arr,2));  
        System.out.println(Array.get(arr,3));  
    }  
}

import java.lang.reflect.*;
public class GetMethodDemo01{
  public static void main(String args[])throws Exception{
    Class<?> c1 = Class.forName("Person");
    Method m = c1.getMethod("sayHello");
    m.invoke(c1.newInstance());
    Method m2 = c1.getMethod("sayHello2",String.class,int.class);
    String str = (String)m2.invoke(c1.newInstance(),"xiazdong",123);
    System.out.println(str);
    Field nameField = c1.getDeclaredField("name");
    Field ageField = c1.getDeclaredField("age");
    nameField.setAccessible(true);
    ageField.setAccessible(true);
    Person obj = (Person)c1.newInstance();
    obj.setName("xzdong");
    obj.setAge(12);
    System.out.println(nameField.get(obj));
    System.out.println(ageField.get(obj));
    Method setName = c1.getMethod("setName",String.class);
    setName.invoke(obj,"changed");
    Method getName = c1.getMethod("getName");
    System.out.println(getName.invoke(obj));
    int tmp[] = {1,2,3};
    Class<?> c3 = tmp.getClass().getComponentType();
    System.out.println(c3.getName());
    System.out.println("第一个数："+Array.get(tmp,0));
    Array.set(tmp,0,5);
    System.out.println("第一个数："+Array.get(tmp,0));
    Object arr = Array.newInstance(c3,5);
    System.arraycopy(tmp,0,arr,0,Array.getLength(tmp));
    System.out.println(Array.get(arr,2));
    System.out.println(Array.get(arr,3));
  }
}

import java.lang.reflect.*;  
interface China{  
    public static final String NAME = "CHINA";  
    public int AGE = 60;  
    public void sayHello();  
    public String sayHello2(String name,int age);  
}  
class Person implements China{  
    private String name;  
    private int age;  
    public String getName(){  
        return name;  
    }  
    public void setName(String name){  
        this.name = name;  
    }  
    public int getAge(){  
        return age;  
    }  
    public void setAge(int age){  
        this.age = age;  
    }  
    public void sayHello(){  
        System.out.println(NAME+"  "+AGE);  
    }  
    public String sayHello2(String name,int age){  
        return name+" "+age;  
    }  
}

import java.lang.reflect.*;  
interface China{  
    public static final String NAME = "CHINA";  
    public int AGE = 60;  
    public void sayHello();  
    public String sayHello2(String name,int age);  
}  
class Person implements China{  
    private String name;  
    private int age;  
    public String getName(){  
        return name;  
    }  
    public void setName(String name){  
        this.name = name;  
    }  
    public int getAge(){  
        return age;  
    }  
    public void setAge(int age){  
        this.age = age;  
    }  
    public void sayHello(){  
        System.out.println(NAME+"  "+AGE);  
    }  
    public String sayHello2(String name,int age){  
        return name+" "+age;  
    }  
}

Android插件化开发基础之Java反射机制研究（2）

十一、操作数组

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