関連ワード:  java generate random number    java generate random number in range    java generate random number between 1 and 10    java generate random number between 1 and 100    java generate random number between 0 and 1    java generate random number between 1000 and 9999    java generate random number 6 digits    java generate random number with n digits    java generate random number from 1 to 100    generate multiple random numbers