tomcat配置中是可以在context.xml中配置數據庫連接池相關信息的，tomcat中間件通過自己的tomcat-jdbc.jar包實現了jdbc數據庫的連接,有時我們不緊想知道那幾個基礎配置信息，還想深入瞭解其他配置屬性。這時我們去tomcat lib目錄下尋找答案。
找到tomcat-jdbc.jar打開來,裏面org\apache\tomcat\jdbc\pool目錄下有我們要找的答案，mbeans-descriptors.xml ，通過裏面的英文註釋我們可以詳細得知具體配置屬性。
<?xml version="1.0"?>
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<mbeans-descriptors>
<mbean name="TomcatJDBCPool"
description="Provides per diagnostic metrics and notifications for JDBC operations"
domain="tomcat"
group="jdbc"
type="org.apache.tomcat.jdbc.pool.DataSource">
<attribute name="className"
description="Fully qualified class name of the managed object"
type="java.lang.String"
writeable="false"/>
<attribute name="size"
description="The number of established connections in the pool, idle and in use"
type="java.lang.Integer"
writeable="false"/>
<attribute name="idle"
description="The number of established connections in the pool that are idle"
type="java.lang.Integer"
writeable="false"/>
<attribute name="numIdle"
description="Same as the idle attribute"
type="java.lang.Integer"
writeable="false"/>
<attribute name="active"
description="The number of established connections in the pool that are in use"
type="java.lang.Integer"
writeable="false"/>
<attribute name="numActive"
description="Same as the active attribute"
type="java.lang.Integer"
writeable="false"/>
<attribute name="poolSweeperEnabled"
description="Returns true if the pool has a background thread running"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="url"
description="The JDBC url for this connection pool"
type="java.lang.String"
writeable="false"/>
<attribute name="driverClassName"
description="The JDBC driver class for this connection pool"
type="java.lang.String"
writeable="false"/>
<attribute name="defaultAutoCommit"
description="The JDBC auto commit setting for new connections"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="defaultReadOnly"
description="The JDBC read only setting for new connections"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="defaultTransactionIsolation"
description="The JDBC transaction isolation setting for new connections"
type="java.lang.Integer"
writeable="false"/>
<attribute name="connectionProperties"
description="The connection properties that will be set for new connections. Format of the string will be [propertyName=property;]*"
type="java.lang.String"
writeable="false"/>
<attribute name="defaultCatalog"
description="The JDBC transaction isolation setting for new connections"
type="java.lang.String"
writeable="false"/>
<attribute name="initialSize"
description="The number of connections opened at pool startup"
type="java.lang.Integer"
writeable="false"/>
<attribute name="maxActive"
description="The maximum number of open connections"
type="java.lang.Integer"
writeable="false"/>
<attribute name="maxIdle"
description="The max number of idle connections"
type="java.lang.Integer"
writeable="false"/>
<attribute name="minIdle"
description="The minimum number of open connections"
type="java.lang.Integer"
writeable="false"/>
<attribute name="maxWait"
description="The time to wait in milliseconds before a SQLException is thrown when a connection is requested"
type="java.lang.Integer"
writeable="false"/>
<attribute name="validationQuery"
description="The query to run during validation"
type="java.lang.String"
writeable="false"/>
<attribute name="validationQueryTimeout"
description="The timeout in seconds before a connection validation queries fail"
type="java.lang.Integer"
writeable="false" />
<attribute name="testOnBorrow"
description="True if validation happens when a connection is requested"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="testOnReturn"
description="True if validation happens when a connection is returned"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="testWhileIdle"
description="True if validation happens when a connection is not in use (idle)"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="timeBetweenEvictionRunsMillis"
description="Sleep time for background thread in between pool checks"
type="java.lang.Integer"
writeable="false"/>
<attribute name="numTestsPerEvictionRun"
description="Not in use"
type="java.lang.Integer"
writeable="false"/>
<attribute name="minEvictableIdleTimeMillis"
description="Minimum amount of time a connection stays idle before it is evicted"
type="java.lang.Integer"
writeable="false"/>
<attribute name="accessToUnderlyingConnectionAllowed"
description="Returns true if one can retrieve the actual JDBC connection"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="removeAbandoned"
description="Returns true if connection in use can be timed out"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="removeAbandonedTimeout"
description="Timeout in seconds for connections in use"
type="java.lang.Integer"
writeable="false"/>
<attribute name="logAbandoned"
description="If true, stack trace will be recorded and printed out for timed out connection"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="loginTimeout"
description="Not in use"
type="java.lang.Integer"
writeable="false"/>
<attribute name="name"
description="The name of the connection pool, will be used in the ObjectName of the actual pool"
type="java.lang.String"
writeable="false"/>
<attribute name="password"
description="For security purposes,this doesn't return anything"
type="java.lang.String"
writeable="false"/>
<attribute name="username"
description="The username used to open connections"
type="java.lang.String"
writeable="false"/>
<attribute name="validationInterval"
description="If larger than zero than validation will only occur after the interval milliseconds has passed"
type="java.lang.Long"
writeable="false"/>
<attribute name="initSQL"
description="A SQL executed once per connection, when it is established"
type="java.lang.String"
writeable="false"/>
<attribute name="testOnConnect"
description="Validate connection after connection has been established"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="jdbcInterceptors"
description="The interceptors configured for this pool"
type="java.lang.String"
writeable="false"/>
<attribute name="jmxEnabled"
description="Register the pool with JMX or not"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="fairQueue"
description="a fair queue is being used by the connection pool"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="abandonWhenPercentageFull"
description="Connections that have been abandoned isn't closed unless connections in use are above this percentage"
type="java.lang.Integer"
writeable="false"/>
<attribute name="maxAge"
description="Time in milliseconds to keep this connection alive even when used"
type="java.lang.Long"
writeable="false"/>
<attribute name="useEquals"
description="Set to true if you wish the ProxyConnection class to use String.equals and set to false when you wish to use == when comparing method names"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="useLock"
description="If true, use a lock when operations are performed on the connection object"
type="java.lang.Boolean"
is="false"
writeable="false"/>
<attribute name="suspectTimeout"
description="Timeout in seconds for connection that suspected to have been abandoned"
type="java.lang.Integer"
writeable="false"/>
<attribute name="rollbackOnReturn"
description="If autoCommit==false then the pool can terminate the transaction by calling rollback on the connection as it is returned to the pool"
type="java.lang.Boolean"
is="false"
writeable="false"/>
<attribute name="commitOnReturn"
description="If autoCommit==false then the pool can complete the transaction by calling commit on the connection as it is returned to the pool"
type="java.lang.Boolean"
is="false"
writeable="false"/>
<attribute name="alternateUsernameAllowed"
description="If true, getConnection(username,password) is allowed"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<attribute name="dataSource"
description="Data source that is injected into the pool"
type="javax.sql.DataSource"
writeable="false"/>
<attribute name="dataSourceJNDI"
description="The JNDI name for a data source to be looked up"
type="java.lang.String"
writeable="false"/>
<attribute name="useDisposableConnectionFacade"
description="If true, connection pool is configured to use a connection facade to prevent re-use of connection after close() has been invoked"
type="java.lang.Boolean"
is="false"
writeable="false"/>
<attribute name="logValidationErrors"
description="Log errors during the validation phase to the log file"
type="java.lang.Boolean"
is="false"
writeable="false"/>
<attribute name="validatorClassName"
description="The name of validator class which implements org.apache.tomcat.jdbc.pool.Validator interface"
type="java.lang.String"
writeable="false"/>
<attribute name="waitCount"
description="The number of threads waiting for a connection"
type="java.lang.Integer"
writeable="false"/>
<attribute name="propagateInterruptState"
description="If true, propagate the interrupt state for a thread that has been interrupted"
type="java.lang.Boolean"
is="false"
writeable="false"/>
<attribute name="ignoreExceptionOnPreLoad"
description="If true, ignore error of connection creation while initializing the pool"
type="java.lang.Boolean"
is="true"
writeable="false"/>
<operation name="checkIdle"
description="forces a check of idle connections"
impact="ACTION"
returnType="void" />
<operation name="checkAbandoned"
description="forces a check of abandoned connections"
impact="ACTION"
returnType="void" />
<operation name="testIdle"
description="forces a validation of abandoned connections"
impact="ACTION"
returnType="void" />
<operation name="purge"
description="Purges all connections in the pool"
impact="ACTION"
returnType="void" />
<operation name="purgeOnReturn"
description="Purges connections when they are returned from the pool"
impact="ACTION"
returnType="void" />
</mbean>
</mbeans-descriptors>
