DBCP

Introduction

OpenJAX DBCP is a light wrapper around the Apache Commons DBCP library, which provides a simple API to describe and initialize a JDBC Database Connection Pool.

OpenJAX DBCP allows a developer to configure a Connection Pool with a standardized XML Schema, which is used by a consumer class to initiate the connection pool. dbcp uses the JAXB framework to significantly reduce the boilerplate code, thus providing a lean API with support for the all possible connection pool configuration variations.

Validating and Fail-Fast

OpenJAX DBCP is based on a XML Schema used to specify the formal of XML documents accepted by the configuration consumer. The XML Schema is designed to use the full power of XML Validation to allow a developer to qiuckly determine errors in his draft. Once a dbcp.xml passes the validation checks, it is almost guaranteed to properly initialize the Connection Pool configured by the file.

Getting Started

Prerequisites

• Java 8 - The minimum required JDK version.
• Maven - The dependency management system.

Example

1. Create a dbcp.xml in src/main/resources/.

   <dbcp id="example"
    xmlns="http://www.openjax.org/dbcp-1.2.xsd"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.openjax.org/dbcp-1.2.xsd http://www.openjax.org/dbcp.xsd">
    <jdbc>
      <url>jdbc:derby:memory:example;create=true</url>
      <driverClassName>org.apache.derby.jdbc.EmbeddedDriver</driverClassName>
    </jdbc>
    <default>
      <catalog>catalog</catalog>
      <autoCommit>true</autoCommit>
      <readOnly>false</readOnly>
      <queryTimeout>300000</queryTimeout>
      <transactionIsolation>READ_UNCOMMITTED</transactionIsolation>
    </default>
    <connection>
      <properties>
        <property name="prop1" value="value1"/>
        <property name="prop2" value="value2"/>
      </properties>
      <initSqls>
        <initSql>SELECT 1 FROM SYSIBM.SYSDUMMY1</initSql>
        <initSql>SELECT 1 FROM SYSIBM.SYSDUMMY1</initSql>
      </initSqls>
    </connection>
    <size>
      <initialSize>0</initialSize>
      <maxTotal>8</maxTotal>
      <maxIdle>8</maxIdle>
      <minIdle>0</minIdle>
      <poolPreparedStatements/>
    </size>
    <pool>
      <queue>lifo</queue>
      <cacheState>false</cacheState>
      <maxWait>INDEFINITE</maxWait>
      <maxConnectionLifetime>INDEFINITE</maxConnectionLifetime>
      <autoCommitOnReturn>true</autoCommitOnReturn>
      <rollbackOnReturn>true</rollbackOnReturn>
      <removeAbandoned on="maintenance" timeout="300"/>
      <abandonedUsageTracking>true</abandonedUsageTracking>
      <allowAccessToUnderlyingConnection>false</allowAccessToUnderlyingConnection>
      <eviction>
        <timeBetweenRuns>300000</timeBetweenRuns>
        <numTestsPerRun>3</numTestsPerRun>
        <minIdleTime>1800000</minIdleTime>
        <softMinIdleTime>INDEFINITE</softMinIdleTime>
        <policyClassName>org.openjax.dbcp.MockEvictionPolicy</policyClassName>
      </eviction>
    </pool>
    <validation>
      <query>SELECT 1 FROM SYSIBM.SYSDUMMY1</query>
      <testOnBorrow>false</testOnBorrow>
      <testOnReturn>false</testOnReturn>
      <testWhileIdle>false</testWhileIdle>
      <fastFail>
        <disconnectionSqlCodes>42X01 42X02 42X03</disconnectionSqlCodes>
      </fastFail>
    </validation>
    <logging>
      <level>INFO</level>
      <logExpiredConnections>true</logExpiredConnections>
      <logAbandoned>true</logAbandoned>
    </logging>

```

1. Add org.openjax:dbcp dependency to the POM.

   <dependency>
     <groupId>org.openjax</groupId>
     <artifactId>dbcp</artifactId>
     <version>1.2.0</version>
   </dependency>

2. In the main() method in App.java, add the following line and let your IDE resolve the missing imports.

   DataSource dataSource = DataSources.createDataSource(ClassLoader.getSystemClassLoader().getResource("dbcp.xml"));

   The dataSource object is a reference to the initialized JDBC Connection Pool configured in dbcp.xml.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

This project is licensed under the MIT License - see the LICENSE.txt file for details.