通过包中的类型转换接口 ref 变量访问类对象

Question

我正在尝试使用forName((和newInstance((内置方法来提供 将为其创建对象的类的名称，接口 ref 变量将指向该类。但是编译器不断抛出异常：

Exception in thread "main" java.lang.ClassNotFoundException: fclas
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at primary.main(primary.java:12) 

正常引用变量声明，即

inter1 obj = new fclass();

&

inter1 obj = new sclass();

似乎工作得很好。

任何帮助将不胜感激TY。

====

====================================================================包中的接口 -- 程序-1

package pack1;    //the interface in the package
public interface inter1
{
void print1();
void print2();
}

====

============================================================接口的实现类 1 -- 程序-2

package pack1;
import pack1.inter1;   // the 1st implementation class
import java.io.*;
public class fclass implements inter1
{
//method bodies
}

====

===============================================================接口的实现类 2 -- 程序-3

package pack1;
import pack1.inter1;     // the 2nd implementation class
import java.io.*;
public class sclass implements inter1
{
//method bodies
}

====

=============================================================主要方法 -- 程序 4

import pack1.fclass;
import pack1.sclass;
import pack1.inter1;    // the main program
import java.io.*;
import java.util.*;
class primary
{
public static void main(String args[]) throws Exception
{
String s1 = "fclass";
Class c = Class.forName(s1);         //THESE 2 LINES R THE PROBLEM
inter1 obj1 = (inter1)c.newInstance(); // THESE 2 LINES R THE PROBLEM
obj1.print1();
obj1.print2();
inter1 obj = new sclass();    // THIS FORMAT WORKS FINE
obj.print1();
obj.print2();
System.out.println("end..........");
}
}

我期待这个输出：

i am print 1 method of package pack1 in fclass
i am print 2 method of package pack1 in fclass
i am print 1 method in package pack1 of sclass
i am print 2 method in package pack1 of sclass
end..........

Answer 1

您需要提供完整的类名：

String s1 = "pack1.fclass";