实例化问题

[summer16md]

我要在MAIN里 调用 member 类的一个getName
不用 Member member = new Member(); 这样实例化
应该怎么实例化??


public class Member
{
private string i;

public meber(A类 a,B类 b,C类 c)
{

}

public void setName(string i)
{

}

public string getName
{

}
}

[wd9053]

public class Member
{
	//........
	
	public static Member createMember(参数列表)
	{
		return new Member(参数列表);
	} 
}

[kent4j]

new Member().getName();

[buzaibeishang4617016]

#2正解

[bayougeng]

反射

回复内容太短了！

[luomf]

方法太多了，
常见的又单例模式、工厂模式，
还有Spring注入

[龙四]

Member member = (Member)Class.forName("Member").newInstance();

[cwjieNo1]

Member member = new Member(); 
member.getName()

new Member().getName()

效果一样，2种写法·

[magicluo]

[Quote=引用 5 楼 luomf 的回复:]
方法太多了，
常见的又单例模式、工厂模式，
还有Spring注入
[/Quote]

工厂模式还是要new 的吧..

用反射试试

package com.reflect;

import java.lang.reflect.Constructor;

public class ReflectTest {

	public static void main(String[] args) {
		Class<Member> clazz = com.reflect.Member.class;
		Constructor<Member> constructor = null;
		Member member = null;
		try {
			constructor = clazz.getConstructor(String.class);
		} catch (Exception e) {
			e.printStackTrace();
		}

		if (constructor != null) {
			try {
				member = (Member) constructor.newInstance("hello");
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		System.out.println(member.getName());  //~output: hello
	}

}

class Member {
	private String str;

	public Member(String args) {
		this.str = args;
	}

	public void setName(String args) {
		this.str = args;
	}

	public String getName() {
		return this.str;
	}
}

[magicluo]

[Quote=引用 6 楼 ticmy 的回复:]
Member member = (Member)Class.forName("Member").newInstance();
[/Quote]

楼主代码中已经提供了无参的构造方法

你这个调用.newInstance() 是不会成功的...

这个只是在类有默认无参构造方法时候才可以

[shaoyongyang]

简单问题搞这么悲剧

[龙四]

木有看见

import java.lang.reflect.Constructor;
import java.sql.Timestamp;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import com.sunyard.sunflow.client.SunflowClient;

class Member
{
 private String i;

 public Member(String a,String b,Integer c)
 {
   
 }

 public void setName(String i)
 {
   
 }

 public String getName()
 {
   return null;
 }
}
public class Test {
	public static void main(String[] args) throws Exception {
		Class clazz = Member.class;
		Constructor constructor = clazz.getConstructor(String.class,String.class,Integer.class);
		constructor.newInstance("arg1","arg2",7);
	}
}

[Quote=引用 9 楼 magicluo 的回复:]

引用 6 楼 ticmy 的回复:
Member member = (Member)Class.forName("Member").newInstance();


楼主代码中已经提供了无参的构造方法

你这个调用.newInstance() 是不会成功的...

这个只是在类有默认无参构造方法时候才可以
[/Quote]

[xu3352]

反射挺好的 有参数的，没参数的都可以的

[Ade子夜]

帮顶！！！