Detail the construction methods, attributes and common methods in reflection

How to get

How to get   public Method of type , Methods that are not limited to this class also include methods that inherit from the parent class public Method

example 1

package keeper;

import java.lang.reflect.Method;

public class Test {

	public static void main(String[] args) {	
		//1. How to get   public  Methods that are not limited to this class also include methods that inherit from the parent class public Method 		
		Class clazz=Student.class;
		Method [] methods =clazz.getMethods(); 
		for (Method method : methods) {
			System.out.println(method.getName());
		}		
	}
}
package keeper;

public class Student {
	public static String name;
	public void doHomework(int a,String [] sd) {		
		System.out.println(name+"fadfsf");
	}
	public Student() {		
	}
	public Student(String name) {
		this.name=name;
	}
}

result ：

doHomework
wait
wait
wait
equals
toString
hashCode
getClass
notify
notifyAll

How to get methods in this class

example 2

package keeper;

import java.lang.reflect.Method;

public class Test {

	public static void main(String[] args) {	
		Class clazz=Student.class;
		Method method;
		try {
			method = clazz.getMethod("doHomework");
			System.out.println(method);
		} catch (Exception e) {
			e.printStackTrace();
		} 		
	}
}
package keeper;

public class Student {
	public static String name;
	public void doHomework() {		
		System.out.println(name+"fadfsf");
	}
	public Student() {		
	}
	public Student(String name) {
		this.name=name;
	}
}

result ：

public void keeper.Student.doHomework()

example 3

package keeper;

import java.lang.reflect.Method;

public class Test {

	public static void main(String[] args) {	
		Class clazz=Student.class;
		Method [] methods =clazz.getDeclaredMethods();
		for (Method method : methods) {
			System.out.println(method.getName());
		}		
	}
}
package keeper;

public class Student {
	public static String name;
	public void doHomework() {		
		System.out.println(name+"fadfsf");
	}
	public Student() {		
	}
	public Student(String name) {
		this.name=name;
	}
}

result ：

doHomework

 

pick up information

example 4

package keeper;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

public class Test {

	public static void main(String[] args) {	
		Class clazz=Student.class;
		try {
			Method method =clazz.getMethod("doHomework", Integer.TYPE,String[].class);
			System.out.println(method.getDeclaringClass());
			System.out.println(Modifier.toString(method.getModifiers()));
			clazz =method .getReturnType();
			System.out.println(clazz.getName());
			System.out.println(method.getName());
			Class [] clazzs =method.getParameterTypes();
			for (Class str : clazzs) {
				System.out.println(str.getName());
			}
		} catch (Exception e) {
			e.printStackTrace();
		}		
	}
}
package keeper;

public class Student {
	public static String name;
	public void doHomework(int a,String [] sd) {		
		System.out.println(name+"fadfsf");
	}
	public Student() {		
	}
	public Student(String name) {
		this.name=name;
	}
}

result ：

class keeper.Student
public
void
doHomework
int
[Ljava.lang.String;

example 5：

package keeper;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

public class Test {

	public static void main(String[] args) {	
		Class clazz=Student.class;
		try {
			Method method =clazz.getDeclaredMethod("doHomework", Integer.TYPE,String[].class);
			method.setAccessible(true);
			Object object =method.invoke(new Student(), 1,new String[] {});
			System.out.println(object);
		} catch (Exception e) {
			e.printStackTrace();
		}	
	}
}
package keeper;

public class Student {
	public static String name;
	private void doHomework(int a,String [] sd) {		
		System.out.println(name+"fadfsf");
	}
	public Student() {		
	}
	public Student(String name) {
		this.name=name;
	}
}

 

result ：

nullfadfsf
null

How to use

attribute
        1. How to get
             a obtain public（ Contains ） Level attribute

package keeper;

import java.lang.reflect.Field;

public class Test {

	public static void main(String[] args) {	
		Class clazz=Student.class;
		Field field;
		try {
			field = clazz.getField("name");
			System.out.println(field.getName());			
		} catch (Exception e) {
			e.printStackTrace();
		}	
	}
}
package keeper;

public class Student {
	public static String name;
	private void doHomework(int a,String [] sd) {		
		System.out.println(name+"fadfsf");
	}
	public Student() {		
	}
	public Student(String name) {
		this.name=name;
	}
}

result ：

name

 

 

             b Getting this type of attribute does not distinguish permissions

package keeper;

import java.lang.reflect.Field;

public class Test {

	public static void main(String[] args) {	
		Class clazz=Student.class;
		Field field;
		try {
			field = clazz.getDeclaredField("name");
			System.out.println(field.getName());			
		} catch (Exception e) {
			e.printStackTrace();
		}	
	}
}
package keeper;

public class Student {
	public static String name;
	private void doHomework(int a,String [] sd) {		
		System.out.println(name+"fadfsf");
	}
	public Student() {		
	}
	public Student(String name) {
		this.name=name;
	}
}

 

result ：

name

       2. pick up information

package keeper;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

public class Test {

	public static void main(String[] args) {	
		Class clazz=Student.class;
		try {// class , Modifier , type , name 
			Method method =clazz.getDeclaredMethod("doHomework", Integer.TYPE,String[].class);
			System.out.println(method.getDeclaringClass());
			System.out.println(Modifier.toString(method.getModifiers()));
			clazz =method .getReturnType();
			System.out.println(clazz.getName());
			System.out.println(method.getName());
			Class [] clazzs =method.getParameterTypes();
			for (Class str : clazzs) {
				System.out.println(str.getName());
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}
package keeper;

public class Student {
	public static String name;
	public void doHomework(int a,String [] sd) {		
		System.out.println(name+"fadfsf");
	}
	public Student() {		
	}
	public Student(String name) {
		this.name=name;
	}
}

result ：

class keeper.Student
public
void
doHomework
int
[Ljava.lang.String;

       3. Operation properties （ Assign and get values ）

package keeper;

import java.lang.reflect.Field;

public class Test {

	public static void main(String[] args) {	
		Class clazz=Student.class;
		try {
			Field field = clazz.getDeclaredField("name");
			field.setAccessible(true);
			Student student = new Student();
			field.set(student, "sgfgsdgdsfg");
			Object object =field.get(student);
			System.out.println(object);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}
package keeper;

public class Student {
	public static String name;
	private void doHomework(int a,String [] sd) {		
		System.out.println(name+"fadfsf");
	}
	public Student() {		
	}
	public Student(String name) {
		this.name=name;
	}
}

result ：

sgfgsdgdsfg