[C3p0] java. SQL. sqlexception: an attempt by a client to checkout a connection...

Java. SQL. sqlexception: an attempt by a client to checkout a connection has timed out.

Error message:

An attempt by a client to checkout a connection has timed out.

Java. SQL. sqlexception: an attempt by a client to checkout a connection has timed out.
At com. mchange. v2. SQL. sqlutils. tosqlexception (sqlutils. Java: 106)
At com. mchange. v2. SQL. sqlutils. tosqlexception (sqlutils. Java: 65)
At com. mchange. v2.c3p0. impl. c3p0pooledconnectionpool. checkoutpooledconnection (c3p0pooledconnectionpool. Java: 527)
At com. mchange. v2.c3p0. impl. abstractpoolbackeddatasource. getconnection (abstractpoolbackeddatasource. Java: 128)
At services. callcenter. Common. dbutilhelper. searchtomap (dbutilhelper. Java: 278)
At services. callcenter. Test. persondaoimpltest. testpersondaoimpl (persondaoimpltest. Java: 36)
At sun. Reflect. nativemethodaccessorimpl. invoke0 (native method)
At sun. Reflect. nativemethodaccessorimpl. Invoke (unknown source)
At sun. Reflect. delegatingmethodaccessorimpl. Invoke (unknown source)
At java. Lang. Reflect. method. Invoke (unknown source)
At JUnit. Framework. testcase. runtest (testcase. Java: 154)
At JUnit. Framework. testcase. runbare (testcase. Java: 127)
At JUnit. Framework. testresult $1. Protect (testresult. Java: 106)
At JUnit. Framework. testresult. runprotected (testresult. Java: 124)
At JUnit. Framework. testresult. Run (testresult. Java: 109)
At JUnit. Framework. testcase. Run (testcase. Java: 118)
At JUnit. Framework. testsuite. runtest (testsuite. Java: 208)
At JUnit. Framework. testsuite. Run (testsuite. Java: 203)
At org. JUnit. Internal. Runners. oldtestclassrunner. Run (oldtestclassrunner. Java: 35)
At org. Eclipse. jdt. Internal. junit4.runner. junit4testreference. Run (junit4testreference. Java: 38)
At org. Eclipse. jdt. Internal. JUnit. Runner. testexecution. Run (testexecution. Java: 38)
At org. Eclipse. jdt. Internal. JUnit. Runner. remotetestrunner. runtests (remotetestrunner. Java: 460)
At org. Eclipse. jdt. Internal. JUnit. Runner. remotetestrunner. runtests (remotetestrunner. Java: 673)
At org. Eclipse. jdt. Internal. JUnit. Runner. remotetestrunner. Run (remotetestrunner. Java: 386)
At org. Eclipse. jdt. Internal. JUnit. Runner. remotetestrunner. Main (remotetestrunner. Java: 196)
Caused by: COM. mchange. v2.resourcepool. timeoutexception: a client timed out while waiting to acquire a resource from Com. mchange. v2.resourcepool. basicresourcepool @ 4ac216 -- timeout awaitavailable ()
At com. mchange. v2.resourcepool. basicresourcepool. awaitavailable (basicresourcepool. Java: 1317)
At com. mchange. v2.resourcepool. basicresourcepool. prelimcheckoutresource (basicresourcepool. Java: 557)
At com. mchange. v2.resourcepool. basicresourcepool. checkoutresource (basicresourcepool. Java: 477)
At com. mchange. v2.c3p0. impl. c3p0pooledconnectionpool. checkoutpooledconnection (c3p0pooledconnectionpool. Java: 525)
... 22 more

When c3p0 is configured in spring, there is a Configuration Attribute checkouttimeout. It is normal to remove this configuration attribute.

The source code is as follows:

Spring configuration file: applicationcontext. xml

<? XML version = "1.0" encoding = "UTF-8"?>
<Beans
Xmlns = "http://www.springframework.org/schema/beans"
Xmlns: xsi = "http://www.w3.org/2001/XMLSchema-instance"
Xsi: schemalocation = "http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">

<Bean id = "propertyconfigurer"
Class = "org. springframework. Beans. Factory. config. propertyplaceholderconfigurer">
<Property name = "location">
<Value> classpath: JDBC. properties </value>
</Property>
</Bean>
<Bean id = "datasource" class = "com. mchange. v2.c3p0. combopooleddatasource">
<Property name = "driverclass" value = "oracle. JDBC. Driver. oracledriver"/>
<Property name = "jdbcurl" value = "$ {JDBC. url}"/>
<Property name = "user" value = "$ {JDBC. Username}"/>
<Property name = "password" value = "$ {JDBC. Password}"/>

<Property name = "autocommitonclose" value = "true"/>

<Property name = "checkouttimeout" value = "$ {cpool. checkouttimeout}"/>

<Property name = "initialpoolsize" value = "$ {cpool. minpoolsize}"/>
<Property name = "minpoolsize" value = "$ {cpool. minpoolsize}"/>

<Property name = "maxpoolsize" value = "$ {cpool. maxpoolsize}"/>
<Property name = "maxidletime" value = "$ {cpool. maxidletime}"/>
<Property name = "acquireincrement" value = "$ {cpool. acquireincrement}"/>
<Property name = "maxidletimeexcessconnections" value = "$ {cpool. maxidletimeexcessconnections}"/>
</Bean>

<! -- Transaction Manager for a single JDBC datasource -->
<Bean id = "transactionmanager" class = "org. springframework. JDBC. datasource. cetcetransactionmanager">
<Property name = "datasource" ref = "datasource"/>
</Bean>

<! -- ====================================== Dao definitions: dbutils implementations ===========================-->

<Bean id = "dbconn" class = "services. callcenter. Common. dbconnection">
<Property name = "ds" ref = "datasource"/>
</Bean>

<Bean id = "dbutilhelper" class = "services. callcenter. Common. dbutilhelper">
<Property name = "ds" ref = "datasource"> </property>
</Bean>
</Beans> public class dbutilhelper {

Private datasource Ds;

Public void setds (datasource DS ){
This. DS = Ds;
}

Public map searchtomap (string SQL ){
Connection conn = NULL;
Map result = NULL;
Queryrunner run = new queryrunner ();
Resultsethandler H = new maphandler ();
Try {
Conn = Ds. getconnection ();
Result = (MAP) Run. Query (Conn, SQL, H );

}
Catch (exception e ){
Log. Warn (SQL );
Log. Warn (E. getmessage (), e );

}
Finally {
Try {
Dbutils. Close (conn );
}
Catch (exception e ){
Log. Warn (E. getmessage (), e );
}
}

Return result;
}

}

The JUnit test code is as follows:

Package ***;

Import java. util. Map;

Import JUnit. Framework. testcase;

Import org. JUnit. test;
Import org. springframework. Context. applicationcontext;
Import org. springframework. Context. Support. classpathxmlapplicationcontext;

Public class persondaoimpltest extends testcase {

Applicationcontext AC = NULL;
@ Test
Public void testpersondaoimpl () throws exception {
Dbutilhelper DB = (dbutilhelper) AC. getbean ("dbutilhelper ");
String SQL = "select user_id from ur_users where user_id = 371 ";
Map M = dB. searchtomap (SQL );
System. Out. println (M. tostring ());
}

Protected void setup () throws exception {
System. Out. println ("ddddd ");
AC = new classpathxmlapplicationcontext ("applicationcontext. xml ");
}
}

For spring code testing, spring uses configuration files to inject certain attributes, while JUnit does not read these configuration files by default. Therefore, when testing the spring class, you need to manually specify the configuration file and then load the configuration information through the classpathxmlapplicationcontext class.

Put the applicationcontext. xml file and JDBC. properties file in the src directory.

Of course, the test code here only uses system. Out. println to print the information directly, and does not use assert to judge the information, so don't go into it!