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
2018-07-28 03:44:51 -03:00
parent 25fb0c94c2
commit fc02400f5f
12 changed files with 267 additions and 221 deletions
@@ -1,85 +0,0 @@
-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<Connection> connectionPool;
-    private final List<Connection> 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<Connection> 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<Connection> 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();
-    }
-}
@@ -1,28 +0,0 @@
-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(){}
-}
@@ -1,18 +0,0 @@
-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();
-}   
@@ -1,25 +0,0 @@
-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(){}
-}
@@ -1,28 +0,0 @@
-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(){}
-}