JavaServer Pages, Second Edition

Integrating Custom Database Actions

The JSTL database access actions look for the default values set by the configuration settings described in Table 22-5 and 22-6.

Table 22-5. Data-source configuration setting

Variable name:	javax.servlet.jsp.jstl.sql.dataSource
Java constant:	Config.SQL_DATA_SOURCE
Java type:	String or javax.sql.DataSource
Set by:	<sql:setDataSource>, context parameter or custom code
Used by:	<sql:query>, <sql:update>, and <sql:transaction>

Table 22-6. Maximum rows configuration setting

Variable name:	javax.servlet.jsp.jstl.sql.maxRows
Java constant:	Config.SQL_MAX_ROWS
Java type:	String or Integer
Set by:	Context parameter or custom code
Used by:	<sql:query>

The data-source setting can be set as a String in this format, in which optional parts are shown between brackets:

url [, [driver] [, [user] [, [password]]]

Commas separate the parts, so if the value for any part contains a comma, it must be escaped with a backslash. This type of value creates a simple DataSource without any pooling capabilities and is intended only for prototype and low-end applications, as described in Chapter 11. It can also be set to a JNDI path for a DataSource made available by the container or to a DataSource created by custom code, such as a servlet or listener. These options are described in detail in Chapter 23.

The maximum rows setting can be set as a String value for a context parameter or as an Integer by custom code. It can be used to prevent run-away ...