java基础帮我我哪里错误了

public class WeekHow{
public static void main(String[] args){
int week = (int)(Math.random()*7);
char ch =(char)('0'+random);
switch(ch){
case'0':
System.out.println("星期天");
break;
case'1':
System.out.println("星期"+ch);
break;
case'2':
System.out.println("星期"+ch);
break;
case'3':
System.out.println("星期"+ch);
break;
case'4':
System.out.println("星期"+ch);
break;
case'5':
System.out.println("星期"+ch);
break;
case'6':
System.out.println("星期"+ch);
break;
default:
System.out.println("输入错误");
}
}
}

char ch =(char)('0'+random);
替换成
char ch =(char)('0'+week);

char ch =(char)('0'+random);
这里是week，不是random