src/java.base/share/classes/java/lang/reflect/Executable.java

*** 120,130 ****
              }
              sb.append(sj.toString());
              sb.append(')');
  
              if (exceptionTypes.length > 0) {
!                 StringJoiner joiner = new StringJoiner(",", "throws ", "");
                  for (Class<?> exceptionType : exceptionTypes) {
                      joiner.add(exceptionType.getTypeName());
                  }
                  sb.append(joiner.toString());
              }
--- 120,130 ----
              }
              sb.append(sj.toString());
              sb.append(')');
  
              if (exceptionTypes.length > 0) {
!                 StringJoiner joiner = new StringJoiner(",", " throws ", "");
                  for (Class<?> exceptionType : exceptionTypes) {
                      joiner.add(exceptionType.getTypeName());
                  }
                  sb.append(joiner.toString());
              }