Oracle user password contains special characters causing login failure

I met a strange question today:
ORA-12154: TNS: Unable to resolve the specified connection identifier. ORA-12154: TNS: Unable to resolve the specified connection identifier
SQL > conn system@webdata
Enter password:
ERROR:
ORA-12154: TNS: Unable to resolve the specified connection identifier
SQL > conn xgplat@webdata
Enter password:
The connected.
Because I thought the client was 32 bits, I used sqlplus to log in to the oracle server, and it was still 1
SQL > conn system@webdata
Enter password:
ERROR:
ORA-12541: TNS:no listener
SQL > conn xgplat@webdata
Enter password:
Connected.
Ask a few people everyone is relatively confused, do not know what the question. I happened to see someone saying it was something to do with the password file, and it occurred to me that all of my system/sys users' passwords contain an @ character.
For example, if my password is 123@456, sqlplus system/123@456 @webdata will be read as sqlplus system/123@456 @webdata, then sqlplus will be read as 123. This will be followed by the database connection string. This will automatically report an error and say: Unable to resolve the specified connection identifier or no listener
On the server after using sqlplus/as sysdba modify sys/system password after login, try to just 1 cut normal again

When Oracle database user password contains special characters such as @, directly use the normal password input, because oracle will parse the characters after @ into the network service name, resulting in login failure
User name: wang Password: oracle@1 Network service name: sun

Linux platform: 'wang/"oracle@1"'@sun --1 double quotation mark password, 1 single quotation mark username + password, i.e. 'username /" password "@ service name
[11:41:14oracle@dvd adump]$sqlplus wang/oracle@1@sun
SQL*Plus: Release 11.2.0.1.0 Production on Tue Oct 30 11:41:24 2012
Copyright (c) 1982, 2009, Oracle. All rights reserved.
ERROR:
ORA-12532: TNS:invalid argument
[11:42:24oracle@dvd adump]$sqlplus 'wang/"oracle@1"'@sun --1 double quotes with password, 1 single quotes with username + password, i.e. 'username /" password "@ service name
SQL*Plus: Release 11.2.0.1.0 Production on Tue Oct 30 11:42:25 2012
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
With the OLAP and Data Mining options
wang@SUN >

Windows platform: wang/"""oracle@1"""@sun-- three double quotation mark passwords, i.e. : user name /""" password ""@ service name
C:\Users\wanglei.ITADMIN > sqlplus wang/oracle@1@sun
SQL*Plus: Release 11.2.0.1.0 Production on Week 2 October 30 13:20:00 2012 SQL*Plus: Release 11.2.0.1.0 Production Week 2 October 30 13:20:00 2012
Copyright (c) 1982, 2010, Oracle. All rights reserved.
ERROR:
ORA-12154: TNS: Unable to resolve the specified connection identifier
Please enter user name:
C:\Users\wanglei.ITADMIN > sqlplus wang/"""oracle@1""" @sun --3 enclosed passwords with double quotes, i.e. : user name /""" password ""@ service name
SQL*Plus: Release 11.2.0.1.0 Production on Week 2 October 30 13:20:30 2012
Copyright (c) 1982, 2010, Oracle. All rights reserved.
To connect to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
With the OLAP and Data Mining options