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POConnection Pool Java
 

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  1. POConnection Pool Java
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    <p>Here is a ConnectionPool that i implemented. Is it a good design to have all variables and methods as static. Please explain why or why not</p> <pre><code>public class MyCp1 { private static final int MAX_SIZE=100; private static final BlockingQueue&lt;Connection&gt; bq; static{ System.out.println("Inside begin static block" ); bq= new ArrayBlockingQueue&lt;Connection&gt;(MAX_SIZE); for(int i=0;i&lt;MAX_SIZE;i++) { try { try { bq.put(makeConnection()); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } System.out.println("total size:" + bq.size()); } public static Connection getConnection() throws InterruptedException { System.out.println("size before getting connection "+ bq.size()+ " Thread name "+ Thread.currentThread().getName()); Connection con=bq.take(); System.out.println("size after getting connection "+ bq.size()+" Thread name "+ Thread.currentThread().getName()); return (con); } public static boolean releaseConnection(Connection con) throws InterruptedException { System.out.println("size before releasing connection "+ bq.size()+" Thread name "+ Thread.currentThread().getName()); boolean bool =bq.add(con); System.out.println("size after releasing connection "+ bq.size()+" Thread name "+ Thread.currentThread().getName()); return (bool); } public static Connection makeConnection() throws SQLException { Connection conn = null; Properties connectionProps = new Properties(); connectionProps.put("user", "root"); connectionProps.put("password", "java33"); try { Class.forName("com.mysql.jdbc.Driver"); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } conn = DriverManager.getConnection("jdbc:" + "mysql" + "://" + "localhost" + ":" + "3306" + "/test", connectionProps); System.out.println("Connected to database"); return conn; } } </code></pre> <p>I know there are issues with exceptional handling and others, but i would appreciate if you can please stick to the above mentioned question</p> <p>EDIT::</p> <p>It looks like using static is not favored. So I refactored as much as i could to get rid of static. While this works, not sure if this is good design </p> <pre><code> public class ConnectionPool { private static final int MAX_SIZE = 100; private BlockingQueue&lt;Connection&gt; bq; private static ConnectionPool cp= new ConnectionPool(); private ConnectionPool(){ System.out.println("inside constructor"); bq = new ArrayBlockingQueue&lt;Connection&gt;(MAX_SIZE); Properties connectionProps = new Properties(); connectionProps.put("user", "root"); connectionProps.put("password", "java33"); try { Class.forName("com.mysql.jdbc.Driver"); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } for (int i = 0; i &lt; MAX_SIZE; i++) { try { bq.put(makeConnection(connectionProps)); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } System.out.println("total size:" + bq.size()); } public static ConnectionPool getInstance() { return cp; } public Connection getConnection() throws InterruptedException { System.out.println("size before getting connection" + bq.size()); Connection con = bq.take(); System.out.println("size after getting connection" + bq.size()); return (con); } public void releaseConnection(Connection con) throws InterruptedException { System.out.println("size before releasing connection" + bq.size()); bq.put(con); System.out.println("size after releasing connection" + bq.size()); //return (bool); } private Connection makeConnection(Properties connectionProps) throws SQLException { Connection conn = null; conn = DriverManager.getConnection("jdbc:" + "mysql" + "://" + "localhost" + ":" + "3306" + "/test", connectionProps); System.out.println("Connected to database"); return conn; } } </code></pre>
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    1. USuser830818
    1. USuser830818
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    1. CONo need to write your implementation of a connection pool. Use [DBCP](http://commons.apache.org/dbcp/) or [C3P0](http://sourceforge.net/projects/c3p0/) . Why re-invent the wheel? :)
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      1. USCoolBeans
    2. CO[BoneCP](http://jolbox.com). Please don't try to reinvent such an extremely important software aspect such as a connection pool as long as you're new to Java and already don't know when to use `static`. It'll kill you sooner or later.
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      1. USBalusC
    3. COIs it an exercise? I recommend you use `commons-dbcp` or `c3p0` open source pools.
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      1. USAlexander Pogrebnyak
 

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