Tomcat JNDI configuration.

1. Add a JNDI data source to Tomcat
We recommend that you use adiminstration of Tomcat. By default, the Administration component is not installed in Tomcat. For detailed installation steps, see install
The component Admin for Tomcat.
Log on to http: // localhost: 8080/admin,
Choose resources> data sources> Create new data source.
Set the JNDI parameter: (MySQL is used as an example here)
JNDI name: JDBC/MySQL (start with the JNDI name)
Data source URL: JDBC: mysql: // localhost: 3306/test (here test is the database name, of course, other parameters can be included, such as: JDBC: mysql: // localhost: 3306/test? User = root & Password = & useunicode = true &
Characterencoding = GBK & autoreconnect = true & failoverreadonly = false)
JDBC Driver Class: COM. MySQL. JDBC. Driver (put the corresponding driver jar package to $ tomcat_home $/common/LIB)
User name: Root (user name)
Password: ***** (password)
Max. Active connections: 4
Max. idle connections: 2
Max. Wait for connection: 5000

2. Configure resouce-ref in a web project
Add the following content to the project's web. xml root node:

<Resource-ref>
<Res-ref-Name> JDBC/MySQL </RES-ref-Name>
<Res-type> javax. SQL. datasource </RES-type>
<Res-auth> container </RES-auth>
<Res-sharing-scope> retriable </RES-sharing-scope>
</Resource-ref>

Note: res-ref-name must be the same as the JNDI name: JDBC/MySQL (JNDI
Name.

3. Set $ atat_home $/CONF/server. xml
Because Tomcat does not automatically add the data source resource information to the context, this step is often ignored.
The content of the current server. XML is:
<? XML version = "1.0" encoding = "UTF-8"?>
<Server>
<Listener classname = "org. Apache. Catalina. Core. aprlifecyclelistener"/>
<Listener classname = "org. Apache. Catalina. mbeans. globalresourceslifecyclelistener"/>
<Listener classname = "org. Apache. Catalina. storeconfig. storeconfiglifecyclelistener"/>
<Listener classname = "org. Apache. Catalina. mbeans. serverlifecyclelistener"/>
<Globalnamingresources>
<Environment
Name = "simplevalue"
Type = "Java. Lang. Integer"
Value = "30"/>
<Resource
Auth = "Container"
Description = "user database that can be updated and saved"
Name = "userdatabase"
Type = "org. Apache. Catalina. userdatabase"
Path Name = "CONF/tomcat-users.xml"
Factory = "org. Apache. Catalina. Users. memoryuserdatabasefactory"/>
<Resource
Name = "JDBC/MySQL"
Type = "javax. SQL. datasource"
Password = "123456"
Driverclassname = "com. MySQL. JDBC. Driver"
Maxidle = "2"
Maxwait = "5000"
Username = "root"
Url = "JDBC: mysql: // localhost: 3306/test"
Maxactive = "4"/>
</Globalnamingresources>
<Service
Name = "Catalina">
<Connector
Port = "8080"
Redirectport = "8443"
Minsparethreads = "25"
Connectiontimeout = "60000"
Connectionlinger = "-1"
Serversotimeout = "0"
Maxsparethreads = "75"
Maxthreads = "150"
Tcpnodelay = "true"
Maxhttpheadersize = "8192">
</Connector>
<Connector
Port = "8009"
Redirectport = "8443"
Protocol = "AJP/1.3">
</Connector>
<Engine
Defaulthost = "localhost"
Name = "Catalina">
<Realm classname = "org. Apache. Catalina. realm. userdatabaserealm"/>
<Host
Appbase = "webapps"
Name = "localhost">
<Context
Docbase = "/test"
Path = "/test"
Reloadable = "true"
DEBUG = "5"
Crosscontext = "true">
<Resource
Name = "JDBC/MySQL"
Type = "javax. SQL. datasource"
Password = "123456"
Maxidle = "2"
Maxwait = "5000"
Username = "root"
Maxactive = "4"
/>
</Context>
</Host>
</Engine>
</Service>
</Server>
If the server. xml file is not modified, the exception cannot create JDBC driver
Class ''for connect URL 'null '.
Pay attention to the final resource of the Code
<Context
Docbase = "/test"
Path = "/test"
Reloadable = "true"
DEBUG = "5"
Crosscontext = "true">
<Resource
Name = "JDBC/MySQL"
Type = "javax. SQL. datasource"
Password = "123456"
Maxidle = "2"
Maxwait = "5000"
Username = "root"
Maxactive = "4"
/>
</Context>
It is found that the <resource/> label does not contain the driverclassname and URL attributes. This is an exception.
Cannot create JDBC driver of class ''for connect URL 'null.
We only need to set the corresponding resource in <globalnamingresources> </globalnamingresources>

<Resource
Name = "JDBC/MySQL"
Type = "javax. SQL. datasource"
Password = "123456"
Driverclassname = "com. MySQL. JDBC. Driver"
Maxidle = "2"
Maxwait = "5000"
Username = "root"
Url = "JDBC: mysql: // localhost: 3306/test"
Maxactive = "4"/>

Replace the resource in the context.

The content of the changed server. xml file is:
<? XML version = "1.0" encoding = "UTF-8"?>
<Server>
<Listener classname = "org. Apache. Catalina. Core. aprlifecyclelistener"/>
<Listener classname = "org. Apache. Catalina. mbeans. globalresourceslifecyclelistener"/>
<Listener classname = "org. Apache. Catalina. storeconfig. storeconfiglifecyclelistener"/>
<Listener classname = "org. Apache. Catalina. mbeans. serverlifecyclelistener"/>
<Globalnamingresources>
<Environment
Name = "simplevalue"
Type = "Java. Lang. Integer"
Value = "30"/>
<Resource
Auth = "Container"
Description = "user database that can be updated and saved"
Name = "userdatabase"
Type = "org. Apache. Catalina. userdatabase"
Path Name = "CONF/tomcat-users.xml"
Factory = "org. Apache. Catalina. Users. memoryuserdatabasefactory"/>
<Resource
Name = "JDBC/MySQL"
Type = "javax. SQL. datasource"
Password = "123456"
Driverclassname = "com. MySQL. JDBC. Driver"
Maxidle = "2"
Maxwait = "5000"
Username = "root"
Url = "JDBC: mysql: // localhost: 3306/test"
Maxactive = "4"/>
</Globalnamingresources>
<Service
Name = "Catalina">
<Connector
Port = "8080"
Redirectport = "8443"
Minsparethreads = "25"
Connectiontimeout = "60000"
Connectionlinger = "-1"
Serversotimeout = "0"
Maxsparethreads = "75"
Maxthreads = "150"
Tcpnodelay = "true"
Maxhttpheadersize = "8192">
</Connector>
<Connector
Port = "8009"
Redirectport = "8443"
Protocol = "AJP/1.3">
</Connector>
<Engine
Defaulthost = "localhost"
Name = "Catalina">
<Realm classname = "org. Apache. Catalina. realm. userdatabaserealm"/>
<Host
Appbase = "webapps"
Name = "localhost">
<Context
Docbase = "/test"
Path = "/test"
Reloadable = "true"
DEBUG = "5"
Crosscontext = "true">
<Resource
Name = "JDBC/MySQL"
Type = "javax. SQL. datasource"
Password = "123456"
Driverclassname = "com. MySQL. JDBC. Driver"
Maxidle = "2"
Maxwait = "5000"
Username = "root"
Url = "JDBC: mysql: // localhost: 3306/test"
Maxactive = "4"/>
</Context>
</Host>
</Engine>
</Service>
</Server>

4. Use the JNDI resource in Java code to obtain the datasource

Javax. Naming. initialcontext CTX = new javax. Naming. initialcontext ();
Datasource DS = (datasource) CTX. Lookup ("Java: COMP/ENV/jdbc/MySQL ");
Connection conn = Ds. getconnection ();

The Code passes the test in jdk1.5.

As mentioned in some documents, in versions earlier than jdk1.5, you can use
Datasource DS = (datasource) CTX. Lookup ("JDBC/MySQL ");
Obtain the datasource.

I have not tested the code.

The above code works well in the J2EE server environment, but a noinitialcontextexception will be reported in main.

The reason for noinitialcontextexception is that necessary JNDI parameters cannot be obtained from system. properties. In the server environment, these parameters are placed in system. properties when the server is started.
You can solve this problem by using the following methods:
Hashtable Env = new hashtable ();
Env. Put (context. initial_context_factory, "weblogic. JNDI. wlinitialcontextfactory ");
Env. Put (context. provider_url, "T3: // localhost: 7001 ");
Initialcontext CTX = new initialcontext (ENV );

Or
System. setproperty (context. initial_context_factory, "weblogic. JNDI. wlinitialcontextfactory ");
System. setproperty (context. provider_url, "RMI: // localhost: 3306/test ");
System. setproperty (context. security_principal, "root ");
System. setproperty (context. security_credentials, "123456 ");

We recommend that you configure the above Code in the configuration file.
Java. Naming. Factory. Initial = weblogic. JNDI. wlinitialcontextfactory
Java. Naming. provider. url = RMI: // localhost: 3306/test
Java. Naming. Security. Principal = user
Java. Naming. Security. Credentials = Password