From fc02400f5f01084a82ba39a851e053dad946c49a Mon Sep 17 00:00:00 2001 From: Alejandro Gervasio Date: Sat, 28 Jul 2018 03:44:51 -0300 Subject: [PATCH] BAEL-1818 A Simple Guide to Connection Pooling in Java (#4823) * Initial Commit * Update parent pom.xml * Update BasicConnectionPool class * Update BasicConnectionPool class * BAEL-1818 removed code from core-java module, cleaned up a little pom files * BAEL-1818 moved the code from connectionpool.connectionpools package to connectionpool --- core-java-persistence/pom.xml | 59 ++++++ .../connectionpool}/BasicConnectionPool.java | 177 +++++++++--------- .../connectionpool}/C3poDataSource.java | 54 +++--- .../connectionpool}/ConnectionPool.java | 40 ++-- .../connectionpool}/DBCPDataSource.java | 50 ++--- .../connectionpool}/HikariCPDataSource.java | 56 +++--- .../BasicConnectionPoolUnitTest.java | 4 +- .../C3poDataSourceUnitTest.java | 1 - .../DBCPDataSourceUnitTest.java | 1 - .../HikariCPDataSourceUnitTest.java | 1 - core-java/pom.xml | 20 -- pom.xml | 25 ++- 12 files changed, 267 insertions(+), 221 deletions(-) create mode 100644 core-java-persistence/pom.xml rename {core-java/src/main/java/com/baeldung/connectionpool/connectionpools => core-java-persistence/src/main/java/com/baeldung/connectionpool}/BasicConnectionPool.java (93%) rename {core-java/src/main/java/com/baeldung/connectionpool/connectionpools => core-java-persistence/src/main/java/com/baeldung/connectionpool}/C3poDataSource.java (89%) rename {core-java/src/main/java/com/baeldung/connectionpool/connectionpools => core-java-persistence/src/main/java/com/baeldung/connectionpool}/ConnectionPool.java (66%) rename {core-java/src/main/java/com/baeldung/connectionpool/connectionpools => core-java-persistence/src/main/java/com/baeldung/connectionpool}/DBCPDataSource.java (88%) rename {core-java/src/main/java/com/baeldung/connectionpool/connectionpools => core-java-persistence/src/main/java/com/baeldung/connectionpool}/HikariCPDataSource.java (91%) rename {core-java => core-java-persistence}/src/test/java/com/baeldung/connectionpool/BasicConnectionPoolUnitTest.java (91%) rename {core-java => core-java-persistence}/src/test/java/com/baeldung/connectionpool/C3poDataSourceUnitTest.java (81%) rename {core-java => core-java-persistence}/src/test/java/com/baeldung/connectionpool/DBCPDataSourceUnitTest.java (81%) rename {core-java => core-java-persistence}/src/test/java/com/baeldung/connectionpool/HikariCPDataSourceUnitTest.java (81%) diff --git a/core-java-persistence/pom.xml b/core-java-persistence/pom.xml new file mode 100644 index 0000000000..0cb142c7b8 --- /dev/null +++ b/core-java-persistence/pom.xml @@ -0,0 +1,59 @@ + + 4.0.0 + com.baeldung.core-java-persistence + core-java-persistence + 0.1.0-SNAPSHOT + jar + core-java-persistence + + com.baeldung + parent-java + 0.0.1-SNAPSHOT + ../parent-java + + + + org.assertj + assertj-core + ${assertj-core.version} + test + + + com.h2database + h2 + ${h2database.version} + + + org.apache.commons + commons-dbcp2 + ${commons-dbcp2.version} + + + com.zaxxer + HikariCP + ${HikariCP.version} + + + com.mchange + c3p0 + ${c3p0.version} + + + + core-java-persistence + + + src/main/resources + true + + + + + 3.10.0 + 1.4.197 + 2.4.0 + 3.2.0 + 0.9.5.2 + + \ No newline at end of file diff --git a/core-java/src/main/java/com/baeldung/connectionpool/connectionpools/BasicConnectionPool.java b/core-java-persistence/src/main/java/com/baeldung/connectionpool/BasicConnectionPool.java similarity index 93% rename from core-java/src/main/java/com/baeldung/connectionpool/connectionpools/BasicConnectionPool.java rename to core-java-persistence/src/main/java/com/baeldung/connectionpool/BasicConnectionPool.java index 1934d0cfc2..289db18c53 100644 --- a/core-java/src/main/java/com/baeldung/connectionpool/connectionpools/BasicConnectionPool.java +++ b/core-java-persistence/src/main/java/com/baeldung/connectionpool/BasicConnectionPool.java @@ -1,85 +1,92 @@ -package com.baeldung.connectionpool.connectionpools; - -import java.sql.Connection; -import java.sql.DriverManager; -import java.sql.SQLException; -import java.util.ArrayList; -import java.util.List; - -public class BasicConnectionPool implements ConnectionPool { - - private final String url; - private final String user; - private final String password; - private final List connectionPool; - private final List usedConnections = new ArrayList<>(); - private static final int INITIAL_POOL_SIZE = 10; - private final int MAX_POOL_SIZE = 20; - - public static BasicConnectionPool create(String url, String user, String password) throws SQLException { - List pool = new ArrayList<>(INITIAL_POOL_SIZE); - for (int i = 0; i < INITIAL_POOL_SIZE; i++) { - pool.add(createConnection(url, user, password)); - } - return new BasicConnectionPool(url, user, password, pool); - } - - private BasicConnectionPool(String url, String user, String password, List connectionPool) { - this.url = url; - this.user = user; - this.password = password; - this.connectionPool = connectionPool; - } - - @Override - public Connection getConnection() throws SQLException { - if (connectionPool.isEmpty()) { - if (usedConnections.size() < MAX_POOL_SIZE) { - connectionPool.add(createConnection(url, user, password)); - } else { - throw new RuntimeException("Maximum pool size reached, no available connections!"); - } - } - - Connection connection = connectionPool.remove(connectionPool.size() - 1); - usedConnections.add(connection); - return connection; - } - - @Override - public boolean releaseConnection(Connection connection) { - connectionPool.add(connection); - return usedConnections.remove(connection); - } - - private static Connection createConnection(String url, String user, String password) throws SQLException { - return DriverManager.getConnection(url, user, password); - } - - public int getSize() { - return connectionPool.size() + usedConnections.size(); - } - - @Override - public String getUrl() { - return url; - } - - @Override - public String getUser() { - return user; - } - - @Override - public String getPassword() { - return password; - } - - public void shutdown() throws SQLException { - usedConnections.forEach(this::releaseConnection); - for (Connection c : connectionPool) { - c.close(); - } - connectionPool.clear(); - } -} +package com.baeldung.connectionpool; + +import java.sql.Connection; +import java.sql.DriverManager; +import java.sql.SQLException; +import java.util.ArrayList; +import java.util.List; + +public class BasicConnectionPool implements ConnectionPool { + + private final String url; + private final String user; + private final String password; + private final List connectionPool; + private final List usedConnections = new ArrayList<>(); + private static final int INITIAL_POOL_SIZE = 10; + private final int MAX_POOL_SIZE = 20; + + public static BasicConnectionPool create(String url, String user, String password) throws SQLException { + List pool = new ArrayList<>(INITIAL_POOL_SIZE); + for (int i = 0; i < INITIAL_POOL_SIZE; i++) { + pool.add(createConnection(url, user, password)); + } + return new BasicConnectionPool(url, user, password, pool); + } + + private BasicConnectionPool(String url, String user, String password, List connectionPool) { + this.url = url; + this.user = user; + this.password = password; + this.connectionPool = connectionPool; + } + + @Override + public Connection getConnection() throws SQLException { + if (connectionPool.isEmpty()) { + if (usedConnections.size() < MAX_POOL_SIZE) { + connectionPool.add(createConnection(url, user, password)); + } else { + throw new RuntimeException("Maximum pool size reached, no available connections!"); + } + } + + Connection connection = connectionPool.remove(connectionPool.size() - 1); + usedConnections.add(connection); + return connection; + } + + @Override + public boolean releaseConnection(Connection connection) { + connectionPool.add(connection); + return usedConnections.remove(connection); + } + + private static Connection createConnection(String url, String user, String password) throws SQLException { + return DriverManager.getConnection(url, user, password); + } + + @Override + public int getSize() { + return connectionPool.size() + usedConnections.size(); + } + + @Override + public List getConnectionPool() { + return connectionPool; + } + + @Override + public String getUrl() { + return url; + } + + @Override + public String getUser() { + return user; + } + + @Override + public String getPassword() { + return password; + } + + @Override + public void shutdown() throws SQLException { + usedConnections.forEach(this::releaseConnection); + for (Connection c : connectionPool) { + c.close(); + } + connectionPool.clear(); + } +} diff --git a/core-java/src/main/java/com/baeldung/connectionpool/connectionpools/C3poDataSource.java b/core-java-persistence/src/main/java/com/baeldung/connectionpool/C3poDataSource.java similarity index 89% rename from core-java/src/main/java/com/baeldung/connectionpool/connectionpools/C3poDataSource.java rename to core-java-persistence/src/main/java/com/baeldung/connectionpool/C3poDataSource.java index 5b91f707a9..78642459d5 100644 --- a/core-java/src/main/java/com/baeldung/connectionpool/connectionpools/C3poDataSource.java +++ b/core-java-persistence/src/main/java/com/baeldung/connectionpool/C3poDataSource.java @@ -1,28 +1,28 @@ -package com.baeldung.connectionpool.connectionpools; - -import com.mchange.v2.c3p0.ComboPooledDataSource; -import java.beans.PropertyVetoException; -import java.sql.Connection; -import java.sql.SQLException; - -public class C3poDataSource { - - private static final ComboPooledDataSource cpds = new ComboPooledDataSource(); - - static { - try { - cpds.setDriverClass("org.h2.Driver"); - cpds.setJdbcUrl("jdbc:h2:mem:test"); - cpds.setUser("user"); - cpds.setPassword("password"); - } catch (PropertyVetoException e) { - e.printStackTrace(); - } - } - - public static Connection getConnection() throws SQLException { - return cpds.getConnection(); - } - - private C3poDataSource(){} +package com.baeldung.connectionpool; + +import com.mchange.v2.c3p0.ComboPooledDataSource; +import java.beans.PropertyVetoException; +import java.sql.Connection; +import java.sql.SQLException; + +public class C3poDataSource { + + private static final ComboPooledDataSource cpds = new ComboPooledDataSource(); + + static { + try { + cpds.setDriverClass("org.h2.Driver"); + cpds.setJdbcUrl("jdbc:h2:mem:test"); + cpds.setUser("user"); + cpds.setPassword("password"); + } catch (PropertyVetoException e) { + e.printStackTrace(); + } + } + + public static Connection getConnection() throws SQLException { + return cpds.getConnection(); + } + + private C3poDataSource(){} } \ No newline at end of file diff --git a/core-java/src/main/java/com/baeldung/connectionpool/connectionpools/ConnectionPool.java b/core-java-persistence/src/main/java/com/baeldung/connectionpool/ConnectionPool.java similarity index 66% rename from core-java/src/main/java/com/baeldung/connectionpool/connectionpools/ConnectionPool.java rename to core-java-persistence/src/main/java/com/baeldung/connectionpool/ConnectionPool.java index 3d5ad06c3d..fa9355721b 100644 --- a/core-java/src/main/java/com/baeldung/connectionpool/connectionpools/ConnectionPool.java +++ b/core-java-persistence/src/main/java/com/baeldung/connectionpool/ConnectionPool.java @@ -1,18 +1,24 @@ -package com.baeldung.connectionpool.connectionpools; - -import java.sql.Connection; -import java.sql.SQLException; -import java.util.List; - -public interface ConnectionPool { - - Connection getConnection() throws SQLException; - - boolean releaseConnection(Connection connection); - - String getUrl(); - - String getUser(); - - String getPassword(); +package com.baeldung.connectionpool; + +import java.sql.Connection; +import java.sql.SQLException; +import java.util.List; + +public interface ConnectionPool { + + Connection getConnection() throws SQLException; + + boolean releaseConnection(Connection connection); + + List getConnectionPool(); + + int getSize(); + + String getUrl(); + + String getUser(); + + String getPassword(); + + void shutdown() throws SQLException;; } \ No newline at end of file diff --git a/core-java/src/main/java/com/baeldung/connectionpool/connectionpools/DBCPDataSource.java b/core-java-persistence/src/main/java/com/baeldung/connectionpool/DBCPDataSource.java similarity index 88% rename from core-java/src/main/java/com/baeldung/connectionpool/connectionpools/DBCPDataSource.java rename to core-java-persistence/src/main/java/com/baeldung/connectionpool/DBCPDataSource.java index 2f33cde883..1e33a08d46 100644 --- a/core-java/src/main/java/com/baeldung/connectionpool/connectionpools/DBCPDataSource.java +++ b/core-java-persistence/src/main/java/com/baeldung/connectionpool/DBCPDataSource.java @@ -1,25 +1,25 @@ -package com.baeldung.connectionpool.connectionpools; - -import java.sql.Connection; -import java.sql.SQLException; -import org.apache.commons.dbcp2.BasicDataSource; - -public class DBCPDataSource { - - private static final BasicDataSource ds = new BasicDataSource(); - - static { - ds.setUrl("jdbc:h2:mem:test"); - ds.setUsername("user"); - ds.setPassword("password"); - ds.setMinIdle(5); - ds.setMaxIdle(10); - ds.setMaxOpenPreparedStatements(100); - } - - public static Connection getConnection() throws SQLException { - return ds.getConnection(); - } - - private DBCPDataSource(){} -} +package com.baeldung.connectionpool; + +import java.sql.Connection; +import java.sql.SQLException; +import org.apache.commons.dbcp2.BasicDataSource; + +public class DBCPDataSource { + + private static final BasicDataSource ds = new BasicDataSource(); + + static { + ds.setUrl("jdbc:h2:mem:test"); + ds.setUsername("user"); + ds.setPassword("password"); + ds.setMinIdle(5); + ds.setMaxIdle(10); + ds.setMaxOpenPreparedStatements(100); + } + + public static Connection getConnection() throws SQLException { + return ds.getConnection(); + } + + private DBCPDataSource(){} +} diff --git a/core-java/src/main/java/com/baeldung/connectionpool/connectionpools/HikariCPDataSource.java b/core-java-persistence/src/main/java/com/baeldung/connectionpool/HikariCPDataSource.java similarity index 91% rename from core-java/src/main/java/com/baeldung/connectionpool/connectionpools/HikariCPDataSource.java rename to core-java-persistence/src/main/java/com/baeldung/connectionpool/HikariCPDataSource.java index 5ed2de181d..cc0cc24520 100644 --- a/core-java/src/main/java/com/baeldung/connectionpool/connectionpools/HikariCPDataSource.java +++ b/core-java-persistence/src/main/java/com/baeldung/connectionpool/HikariCPDataSource.java @@ -1,28 +1,28 @@ -package com.baeldung.connectionpool.connectionpools; - -import com.zaxxer.hikari.HikariConfig; -import com.zaxxer.hikari.HikariDataSource; -import java.sql.Connection; -import java.sql.SQLException; - -public class HikariCPDataSource { - - private static final HikariConfig config = new HikariConfig(); - private static final HikariDataSource ds; - - static { - config.setJdbcUrl("jdbc:h2:mem:test"); - config.setUsername("user"); - config.setPassword("password"); - config.addDataSourceProperty("cachePrepStmts", "true"); - config.addDataSourceProperty("prepStmtCacheSize", "250"); - config.addDataSourceProperty("prepStmtCacheSqlLimit", "2048"); - ds = new HikariDataSource(config); - } - - public static Connection getConnection() throws SQLException { - return ds.getConnection(); - } - - private HikariCPDataSource(){} -} +package com.baeldung.connectionpool; + +import com.zaxxer.hikari.HikariConfig; +import com.zaxxer.hikari.HikariDataSource; +import java.sql.Connection; +import java.sql.SQLException; + +public class HikariCPDataSource { + + private static final HikariConfig config = new HikariConfig(); + private static final HikariDataSource ds; + + static { + config.setJdbcUrl("jdbc:h2:mem:test"); + config.setUsername("user"); + config.setPassword("password"); + config.addDataSourceProperty("cachePrepStmts", "true"); + config.addDataSourceProperty("prepStmtCacheSize", "250"); + config.addDataSourceProperty("prepStmtCacheSqlLimit", "2048"); + ds = new HikariDataSource(config); + } + + public static Connection getConnection() throws SQLException { + return ds.getConnection(); + } + + private HikariCPDataSource(){} +} diff --git a/core-java/src/test/java/com/baeldung/connectionpool/BasicConnectionPoolUnitTest.java b/core-java-persistence/src/test/java/com/baeldung/connectionpool/BasicConnectionPoolUnitTest.java similarity index 91% rename from core-java/src/test/java/com/baeldung/connectionpool/BasicConnectionPoolUnitTest.java rename to core-java-persistence/src/test/java/com/baeldung/connectionpool/BasicConnectionPoolUnitTest.java index 5edc6bba94..479cd0db25 100644 --- a/core-java/src/test/java/com/baeldung/connectionpool/BasicConnectionPoolUnitTest.java +++ b/core-java-persistence/src/test/java/com/baeldung/connectionpool/BasicConnectionPoolUnitTest.java @@ -1,10 +1,8 @@ package com.baeldung.connectionpool; -import com.baeldung.connectionpool.connectionpools.BasicConnectionPool; -import com.baeldung.connectionpool.connectionpools.ConnectionPool; import java.sql.Connection; import java.sql.SQLException; -import java.util.List; + import static org.assertj.core.api.Assertions.assertThat; import static org.junit.Assert.assertTrue; import static org.junit.Assert.fail; diff --git a/core-java/src/test/java/com/baeldung/connectionpool/C3poDataSourceUnitTest.java b/core-java-persistence/src/test/java/com/baeldung/connectionpool/C3poDataSourceUnitTest.java similarity index 81% rename from core-java/src/test/java/com/baeldung/connectionpool/C3poDataSourceUnitTest.java rename to core-java-persistence/src/test/java/com/baeldung/connectionpool/C3poDataSourceUnitTest.java index a02daa40f6..a07fa9e74b 100644 --- a/core-java/src/test/java/com/baeldung/connectionpool/C3poDataSourceUnitTest.java +++ b/core-java-persistence/src/test/java/com/baeldung/connectionpool/C3poDataSourceUnitTest.java @@ -1,6 +1,5 @@ package com.baeldung.connectionpool; -import com.baeldung.connectionpool.connectionpools.C3poDataSource; import java.sql.SQLException; import static org.junit.Assert.assertTrue; import org.junit.Test; diff --git a/core-java/src/test/java/com/baeldung/connectionpool/DBCPDataSourceUnitTest.java b/core-java-persistence/src/test/java/com/baeldung/connectionpool/DBCPDataSourceUnitTest.java similarity index 81% rename from core-java/src/test/java/com/baeldung/connectionpool/DBCPDataSourceUnitTest.java rename to core-java-persistence/src/test/java/com/baeldung/connectionpool/DBCPDataSourceUnitTest.java index 9583eedf4b..43aaf330b6 100644 --- a/core-java/src/test/java/com/baeldung/connectionpool/DBCPDataSourceUnitTest.java +++ b/core-java-persistence/src/test/java/com/baeldung/connectionpool/DBCPDataSourceUnitTest.java @@ -1,6 +1,5 @@ package com.baeldung.connectionpool; -import com.baeldung.connectionpool.connectionpools.DBCPDataSource; import java.sql.SQLException; import static org.junit.Assert.assertTrue; import org.junit.Test; diff --git a/core-java/src/test/java/com/baeldung/connectionpool/HikariCPDataSourceUnitTest.java b/core-java-persistence/src/test/java/com/baeldung/connectionpool/HikariCPDataSourceUnitTest.java similarity index 81% rename from core-java/src/test/java/com/baeldung/connectionpool/HikariCPDataSourceUnitTest.java rename to core-java-persistence/src/test/java/com/baeldung/connectionpool/HikariCPDataSourceUnitTest.java index 6b78815797..b20ce70efd 100644 --- a/core-java/src/test/java/com/baeldung/connectionpool/HikariCPDataSourceUnitTest.java +++ b/core-java-persistence/src/test/java/com/baeldung/connectionpool/HikariCPDataSourceUnitTest.java @@ -1,6 +1,5 @@ package com.baeldung.connectionpool; -import com.baeldung.connectionpool.connectionpools.HikariCPDataSource; import java.sql.SQLException; import static org.junit.Assert.assertTrue; import org.junit.Test; diff --git a/core-java/pom.xml b/core-java/pom.xml index 0b69685e14..b83cb478d4 100644 --- a/core-java/pom.xml +++ b/core-java/pom.xml @@ -158,21 +158,6 @@ jmimemagic ${jmime-magic.version} - - org.apache.commons - commons-dbcp2 - ${commons-dbcp2.version} - - - com.zaxxer - HikariCP - ${HikariCP.version} - - - com.mchange - c3p0 - ${c3p0.version} - org.javassist @@ -544,11 +529,6 @@ 3.10.0 - - 2.4.0 - 3.2.0 - 0.9.5.2 - 2.19.1 4.3.4.RELEASE diff --git a/pom.xml b/pom.xml index 263e4df637..1730449509 100644 --- a/pom.xml +++ b/pom.xml @@ -312,6 +312,7 @@ core-java-collections core-java-io core-java-8 + core-java-persistence core-kotlin core-groovy core-java-concurrency @@ -877,7 +878,7 @@ spring-static-resources hazelcast hbase - + hystrix image-processing immutables @@ -906,11 +907,11 @@ linkrest logging-modules/log-mdc logging-modules/log4j - + logging-modules/logback lombok mapstruct - + maven mesos-marathon msf4j @@ -962,25 +963,25 @@ spring-cucumber spring-ejb spring-aop - + persistence-modules/spring-data-dynamodb spring-data-keyvalue spring-data-mongodb persistence-modules/spring-data-neo4j - + spring-data-rest persistence-modules/spring-data-solr spring-dispatcher-servlet spring-exceptions spring-freemarker persistence-modules/spring-hibernate-3 - + persistence-modules/spring-hibernate-5 persistence-modules/spring-data-eclipselink spring-integration spring-jenkins-pipeline spring-jersey - + spring-jms spring-jooq persistence-modules/spring-jpa @@ -1041,13 +1042,13 @@ testing-modules/testing testing-modules/testng video-tutorials - + xmlunit-2 struts-2 apache-velocity apache-solrj rabbitmq - + persistence-modules/spring-data-gemfire mybatis spring-drools @@ -1090,7 +1091,7 @@ vertx metrics httpclient - + jmeter --> @@ -1233,6 +1234,4 @@ 3.8 - - - + \ No newline at end of file