Tomcat4 database connection pool configuration add by: Fanyhan This article mainly introduces the configuration of the database connection pool under Tomcat4.1.19, and the JNDI lookup of the connection pool, and provides the corresponding
Test code. Finally, the common problems and solutions in the configuration and application process are pointed out. I. Tomcat introduction Tomcat is one of the subprojects of Apache Jakarta, which is a JSP recommended by Sun. As an excellent application service
Merries, Tomcat provides many universal component features such as database connection pool, SSL, proxy, where connecting pools are newly added in 4.0 or higher.
Can, the application is very wide. Second, the text configuration environment Tomcat4.1.19 jbuilder 8.0 win2000 three, the DBCP configuration for Tomcat4.1.19 is convenient, set the connection pool in root, JNDI name is JDBC / SQLServerDB , Database server IP is
192.168.0.47, SID is HRNTEST, the configuration steps are as follows. Step 1: Configure server.xml to find "0" /> -> "" "DocBase =" root "" "
Change it to
SENAME = HRNTEST
Resource item (ie the DataSource object of the connection pool), there are 3 attributes name, auth, type, name item is the name definition of JNDI,
The program can find this object through JNDI, here is named JDBC / SQLServerDB; Auth item, connect pool management rights attribute, here
Container, stated that it is container management; Type item is the type of object, this is valued here javax.sql.datasource, this is declared as a database
Pell. In the next
The user name, password, JDBC driver, and database address of the database are sequentially. Factory parameters:
That is, the base object factory, this is valued in org.apache.commons.dbcp.basicDataSourceFactory, the factory that comes with DBCP, also
Can be used. Driverclassname parameters:
That is, the Database's JDBC driver name, the specific value is: SQL Server 2000: com.microsoft.jdbc.sqlserver.sqlserverDriver first to download the installation SQLServer-JDBC-driver, then put the three JAR files under LIB in Tomcat / Common / Lib. Mysql: org.gjt.mm.mysql.driver mysql JDBC driver package mm.mysql-2.0.14.jar. Oracle8.1.7: Oracle.jdbc.driver.OracleDriver Oracle8.1.7 JDBC driver package name is classs.jar, generally located in the Oracle installation directory
Under the ORA81 / JDBC / LIB directory, the initial extension is ZIP, need to manually change the classs.zip to classes.jar, and put it
Under Tomcat / Common / LIB. Oracle.jdbc.driver.Orcledgedriver This class is provided by classes.jar. URL parameters:
That is, the address of the database. (Different databases are different) SQL Server 2000: JDBC: Microsoft: SQLServer: //192.168.0.47: 1433; DatabaseName = HRNTEST ORACLE8.1.7: JDBC: Oracle: Thin: @ 192.168.0.47: 1521: HRNTESTUSERNAME parameters :
That is, the username of the database is connected.
Password parameter:
That is, the password of the database is connected. MaxActive, Maxidle and Maxwait Parameters:
Maxactive is the maximum number of connections, which is 20, indicating that there are up to 20 databases at the same time. MaxIdle is the maximum number of idle connections, here is 20, indicating that it can still be kept 20 idle even when there is no database connection.
Connection, not cleared, is in standby. MaxWait is the maximum number of seconds, here is all -1, indicating unlimited waits until the timeout can be taken, and the value is 9000, indicating 9 seconds. Step 2: Configure Web.xml Open Web.xml under WebApps / Root / Web-INF, add the following:
Part III: Configuring Tomcat (add classes) Copy the three JAR files in the Microsoft SQL Server 2000 Driver for JDBC / LIB directory to the Tomcat installation directory
COMMON / LIB. Configure completion
Fourth, the test code database is as follows: Create Table Test (ID varchar (12)) method 1: Write a JSP file (TestDb.jsp), put it in a WebApps / root directory, open Tomcat Run Page test
test.
The contents of the page TestDb.jsp are as follows:
<% @ Page ContentType = "Text / HTML; Charset = GBK"%> <% @ page import = "java.sql. *"%> <% @ page import = "javax.naming. *"%>
<% Try {context initctx = new initialcontext (); context ctx = (context) INITCTX.LOOKUP ("java: comp / env"); // Get connection pool object Object obj = (Object) CTX.lookup ("JDBC / SQLServerDB "); // Type conversion javax.sql.datasource DS = (javax.sql.datasource) obj; connection conn = ds.getConnection (); statement stmt = conn.createstatement (); string strsql =" Insert INTO TEST ID, name) VALUES ('00001', 'fany') "; stmt.executeUpdate (strsql); strsql =" select "; resultSet RS = stmt.executeQuery (strsql); if (rs.next )) {Out.println (rs.getstring (1)); out.println (rgetstring (2));}}}} catch (exception ex) {EX.PrintStackTrace (); throw new SQLEXCEPTION ("Cannot Get Connection Pool ");}%> Method 2: Write a database connection class content as follows:
Static string jndiname = "jdbc / sqlserverdb";
/ * ** acquired from an idle database connection pool * @return Connection * @exception Exception * / public static Connection getConnection () throws Exception {Connection conn = null; try {Context initCtx = new InitialContext (); Context ctx = (Context) INITCTX.LOOKUP ("Java: Comp / ENV"); // Gets the connection pool object Object obj = (Object) CTX.lookup (JNDINAME); // Type conversion javax.sql.dataSource DS = (Javax. Sql.datasource) OBJ; // Get the database connection conn = ds.getConnection ();} catch (java.lang.securityException se) {throw se;} catch (exception e) {E.PrintStackTrace (); throw e;} Return conn;
}
