Combining algorithm random number output specification bis (object-oriented ideas)

{class Tests2020031702 public 
	Private the RANGE static String = "0123456789"; 

	public static void main (String [] args) { 
		// 1-8 bit random combinations 
		for (int len =. 1; len <=. 5; len ++) { 
			the DashBoard Dashboard = the dashBoard new new (len); 
			// initial value 
			dashBoard.println (); 
			the while (dashBoard.add ()) { 
				dashBoard.println (); 
			} 
			// maximum 
			dashBoard.println (); 
		} 
	} 

	/ ** 
	 * dashboard 
	 * / 
	static the dashBoard class { 
		char [] chars; 
		char lastChar = RANGE.charAt (RANGE.length () -. 1); 

		public the dashBoard (int length) { 
			// dashboard display digits  
			this.chars = new char [length] ;
			// initialize
			for (int I = 0; I <chars.length; I ++) { 
				chars [I] = RANGE.charAt (0); 
			} 
		} 

		/ ** 
		 * plus. 1 
		 * @return success 
		 * / 
		public Boolean the Add () { 
			/ / accumulation starts from the last one 
			for (int I = chars.length -. 1; I> = 0; i--) { 
				// add. 1 
				IF (RANGE.indexOf (String.valueOf (chars [I])) <( RANGE.length () -. 1)) { 
					chars [I] = RANGE.charAt (RANGE.indexOf (String.valueOf (chars [I])) +. 1); 
					// do not spill out of the loop 
					BREAK; 
				} 
				chars [I ] = RANGE.charAt (0); 
			} 
			// determines whether the maximum value 
			for (int I = 0; I <chars.length; I ++) {  
				iF (! chars [I] = lastChar) {
					return to true; 
				} 
			}
			return false;
		}

		/**
		 * 打印
		 */
		public void println() {
			for (int i = 0; i< chars.length; i++) {
				System.out.print(chars[i]);
			}
			System.out.println();
		}
	}
}

 print

0
1
2
3
4
5
6
7
8
9
00
01
02
03
04

 Modify the range

private static String RANGE = "abcdefg";

 Reprint

to 
b 
c 
d 
e 
f 
g 
c 
most 
ac 
hat 
EU