JDBC Configuration Errors_JDBC 4.0 and Oracle JDeveloper for J2EE Development-QQ阅读男生轻小说网

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JDBC Configuration Errors

You might get errors while configuring a JDBC connection. If you are using MySQL, and the connection URL is incorrect, or the MySQL database is not running, the following error message is generated:

Communications link failure

If you are using Oracle database, some possible connection configuration errors are listed below:

IO exception: The Network Adapter could not establish the connection IO exception: Connection refused

The The Network Adapter could not establish the connection exception is caused by one or more of the following configuration errors:

The database host name, port number, or database instance name is wrong.
The database TNSListener has not been started. The TNSListener may be started with the lsnrctl utility.
```
C:\>lsnrctl start 
```

The Connection refused exception is caused by one or more of the following configuration errors:

The database SID specified is incorrect.
The database instance has not been started. To start the database instance connect to SQL*Plus as SYSDBA.
```
C:\>sqlplus SYS/<pwd> AS SYSDBA 
```

At the SQL prompt, start the database instance with the startup command.

SQL>startup