我正在尝试使用正则表达式在Java中查找字符串中的一些匹配项。实际的正则表达式是
^(interface \X*!)
当我这样做时，我使用
^(interface \\X*!)
现在这会在索引13附近抛出非法/不支持的转义序列。我搜索了一下板，发现它实际上应该是四个反斜杠才能使它工作。但如果我使用
^(interface \\\\X*!)
它不返回任何匹配项。任何指针都会非常有用。
只是样本匹配就像
interface ABC
temp
abc
xyz
!
答案 0 :(得分：2)
.MODEL small
.STACK 100h
.DATA
uinp db 13, 0, 14 DUP('$') ; Username register input, max 12 letters ;
pinp db 17, 0, 16 DUP('$') ; Password register input, max 16 letters
ulinp db 13, 0, 14 DUP('$') ; Username login input
plinp db 17, 0, 16 DUP('$') ; Password login input
wlmsg db " Welcome user! ", 10, 13, "$" ;
wlmsg2 db " Please login... ", 10, 13, "$" ; Welcome messages
wlmsg3 db " Press any key.. ", 10, 13, "$" ;
umsg db " Username: ", 10, 13, ;
db " Password: $", 10, 13, ; Username and password text
question db " Would you like to ", 10, 13 ;
db " (R) Register ", 10, 13 ; Main menu text
db " (L) Login ", 10, 13 ;
db " ( ) $", 10, 13 ;
errormsg db " ERROR! ", 10, 13 ;
db " Please make sure you ", 10, 13 ;
db " followed the instructions ", 10, 13 ; Error message ; JUST TO CLARIFY:
db " and wrote your choice ", 10, 13 ; ; At first I wanted to create a file, write the username and password onto it
db " with CAPITAL LETTERS $", 10, 13 ; ; and then read it. Turn's out that it was out of the course scope and it's not
; critical for the program.
errormsg2 db " username or password are incorrect ", 10, 13 ; Second error message
db " try again later... $"
afterRegisterMsg db " Nice, now go back to menu $", 10, 13 ; After registration message
sLogin db " ", 10, 13
db " ********************************* ", 10, 13
db " *You have succesfully logged in!* ", 10, 13 ; Message after succesful match to the user name and password
db " *********************************$", 10, 13
choice db ' ' ;o Choice of user in menu
fLogin db " Username and password are incorrect.",10 ,13 ; Fail to login message
db " Please try again and make sure", 10, 13
db " enterd the right username and", 10, 13
db " password. $", 10, 13
.CODE
mov ax, @data
mov ds, ax
Welcome:
mov dx, offset wlmsg ; First message
mov ah, 09h
int 21h
mov dx, offset wlmsg2 ; Second message
mov ah, 09h
int 21h
mov dx, offset wlmsg3 ; Third message
mov ah, 09h
int 21h
mov ah, 01h ; Wait for user to continue
int 21h ;
call clear ; Clear screen
Menu:
call clear ; Clear screen
mov dx, offset question ;
mov ah, 09h ; Print menu
int 21h ;
mov dh, 03h ;
mov dl, 12 ;
mov bh, 0 ; Set cursor to (12,3)
mov ah, 02h ;
int 10h
mov ah, 01h ;
int 21h ; Reads user's choice
cmp al, 'R' ; Check if user picked register option
je Register ; Jump to 1register label
cmp al, 'L' ; Check if user picked login option
je Login ; Jump to login label
jmp Error
Error:
call clear
mov dx, offset errormsg ;
mov ah, 09h ; Print error message
int 21h ;
mov ah, 08h ; Wait for user to continue
int 21h ;
jmp Menu ; Jump back to menu
Register:
call clear ; Clear screen
mov dx, offset umsg ;
mov ah, 09h ; Print username
int 21h ;
mov dx, 18 ;
mov bh, 0 ; Set cursor to (18,0)
mov ah, 02h ;
int 10h
mov dx, offset uinp ;
mov ah, 0Ah ; Read username input and puts it into uinp
int 21h ;
mov dh, 01h ;
mov dl, 18 ;
mov bh, 0 ; Set cursor to (18,1)
mov ah, 02h ;
int 10h
mov dx, offset pinp ;
mov ah, 0Ah ; Reads password input and puts it into pinp
int 21h ;
call clear
mov dx, offset afterRegisterMsg ;
mov ah, 09h ; Print after registration message
int 21h ;
mov ah, 01h ; Waits for user to click a button
int 21h ;
jmp menu ; Go back to menu
Login:
call clear ; Clear screen
mov dx, offset umsg ;
mov ah, 09h ; Prints username and password
int 21h ;
mov dx, 18 ;
mov bh, 0 ; Set cursor to (18,0)
mov ah, 02h ;
int 10h
mov dx, offset ulinp ;
mov ah, 0Ah ; Reads username login input
int 21h ;
mov dh, 01h ;
mov dl, 18 ;
mov bh, 0 ; Set cursor to (18,1)
mov ah, 02h ;
int 10h
mov dx, offset plinp ;
mov ah, 0Ah ; Reads password login input
int 21h ;
call chkLength ; Match length
mov dx, 0 ;
mov cx, 0 ; Reset all the registers for compUser
mov ax, 0 ;
jmp CompareU ; Check if username is correct
hlt
chkLength: ;
mov dh, [uinp + 1] ; Finding the length of the username that the user have enterd
mov dl, [ulinp + 1] ; " " "
cmp dh, dl ; Comparing their lengths
jne Error2 ; If their lengths aren't equal there will be an error
mov dh, [pinp + 1] ; Finding the length of the password that the user have enterd
mov dl, [plinp + 1] ; " " "
cmp dh, dl ; Comparing their lengths
jne Error2 ; Error if the strings don't have the same lengths
ret ; Go back to the login main
Error2: ; After comparing error
call clear ; call clear
mov dx, offset errormsg2 ;
mov ah, 09h ; Error in case the user entered wrong username and password
int 21h ;
mov ah, 01h ; Wait for click
int 21h ;
call clear ; Clear screen
int 20h ; End the program
CompareU: ; Comparing the usernames
mov dh, offset uinp ; Get uinp address
add dh, 2 ; Add 2 to skip to the actaul string
mov dl, offset ulinp ; Get ulinp address
add dl, 2 ; Add 2 to skip to the actaul string
add dh, cl ; Adding the index to the address so it can know what character to go through
add dl, cl ; " "
push cx ; Maintaining the index count
mov bh, 0 ;
mov bl, dh ; Going into the memory to get uinp actaul string
mov ch, [bx] ;
mov bh, 0 ;
mov bl, dl ; Going into the memory to get ulinp actaul string
mov cl, [bx] ;
cmp cl, ch ; Comparing the two usernames
jne Error2 ; If the usernames are not the same it sum as an error
mov bh, 0 ;
mov bl, dh ;
mov al, [bx] ; Cheking if the string ended
cmp al, '$' ;
je resetReg ; Reset all the registers for the password compare
pop cx ; Pop the index back out again so it could be increased
inc cl ; Increase the index by 1 to go over the next charachter
jmp CompareU ; Jump back again to the head of the label to check all over again
resetReg: ; Reset registers label
mov ax, 0 ; Reset ax
mov bx, 0 ; Reset bx
mov cx, 0 ; Reset cx
mov dx, 0 ; Reset dx
jmp CompareP ; Go to the password comparing
CompareP: ; Comparing the passwords
mov dh, offset pinp ; Get pinp address
add dh, 2 ; Add 2 to skip to the actaul string
mov dl, offset plinp ; Get plinp address
add dl, 2 ; Add 2 to skip to the actaul string
add dh, cl ; Adding the index to the address so it can know what character to go through
add dl, cl ; " "
push cx ; Maintaining the index count
mov bh, 0 ;
mov bl, dh ; Going into the memory to get pinp actaul string
mov ch, [bx] ;
mov bh, 0 ;
mov bl, dl ; Going into the memory to get plinp actaul string
mov cl, [bx] ;
cmp cl, ch ; Comparing the two passwords
jne Error2 ; If the passwords are not the same it sum as an error
mov bh, 0 ;
mov bl, dh ;
mov al, [bx] ; Cheking if the string ended
cmp al, '$' ;
je successLogin ; Letting the user know that he enterd and both username and password are true
pop cx ; Pop the index back out again so it could be increased
inc cl ; Increase the index by 1 to go over the next charachter
jmp CompareP ; Jump back again to the head of the label to check all over again
successLogin: ; Successful login message
call clear ; Clearing the screen
mov dx, offset sLogin ;
mov ah, 09h ; Print the successful login message
int 21h ;
mov ah, 01h ; Waiting for the user to make it's final click
int 21h ;
int 20h ; End of the program in case the login was succesful
clear:
mov ah, 06h ;
mov al, 00h ;
mov bh, 0Fh ;
mov cx, 0 ; Clear Screen
mov dh, 100 ;
mov dl, 40 ;
int 10h ;
mov dx, 0 ;
mov bh, 0 ; Set cursor to (0,0)
mov ah, 02h ;
int 10h
ret ; Return back to where it was called
int 20h ; End of program no matter what
构造来自Perl，而Javadoc for java.util.Pattern在比较Perl 5 部分明确指出它不受支持。
在Java中，您必须使用不同的构造。但是这部分已在https://stackoverflow.com/a/39561579中得到解答。
答案 1 :(得分：1)
为了匹配您在注释中标识的模式，使用Java，这样的事情应该起作用：
Pattern p = Pattern.compile("interface[^!]*!", Pattern.DOTALL);
Matcher m = p.matcher("interface ABC\ntemp\nabc\nxyz\n!"); // your test string
if (m.matches()) {
//
}
此模式匹配以＆＃34; interface＆＃34;开头的任何字符串，后跟除了＆＃34;！＆＃34;之外的任何字符的零个或多个，后跟＆＃34;！＆＃34;。
Pattern.DOTALL告诉它除了所有其他字符外，＆＃34;。＆＃34;还应匹配回车和换行符。有关DOTALL的详细信息，请参阅this。