Add a db pool in a slightly elegant way without having to modify the …

…existing code base TOO much!:

Database pools required you to get a Connection object and then close it afterwards. LWC has 2000+ lines of database code. Modifying every instance of this is extremely (!!) time consuming and very inconvenient.

Instead of doing this we exploit the fact that in LWC's usecase, once a PreparedStatement or ResultSet is closed, everything above it is closed, e.g a close chain: ResultSet -> PreparedStatement -> Connection. This is done automatically by the new backing AutoClosingPreparedStatement and AutoClosingResultSet.

This however did require manually modifying anything that used raw Statement objects.

This means that this build truly is a "dev" build not an unreleased stable build. Care should be taken with this build.

build.xml

@@ -65,6 +65,9 @@
         <mkdir dir="${bin}/core/"/>
         <mkdir dir="${bin}/core/resources/"/>
 
+        <!-- shade dbpool -->
+        <unzip src="lib/dbpool-5.0.jar" dest="${bin}/core/" />
+
         <!-- Timestamp, bitches -->
         <tstamp>
             <!-- Date format: MONTH DD YYYY e.g January 25, 2012 -->

src/main/java/com/griefcraft/io/BackupManager.java

@@ -40,6 +40,7 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.Statement;
 import java.text.SimpleDateFormat;
@@ -250,7 +251,8 @@ public void run() {
                         database.load();
 
                         // TODO separate stream logic to somewhere else :)
-                        Statement resultStatement = database.getConnection().createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
+                        Connection connection =  database.createConnection();
+                        Statement resultStatement = connection.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
 
                         if (lwc.getPhysicalDatabase().getType() == Database.Type.MySQL) {
                             resultStatement.setFetchSize(Integer.MIN_VALUE);
@@ -324,6 +326,7 @@ public Void call() throws Exception {
                         // close the sql statements
                         result.close();
                         resultStatement.close();
+                        connection.close();
 
                         // close the backup file
                         backup.close();

src/main/java/com/griefcraft/lwc/LWC.java

@@ -129,6 +129,7 @@
 import org.bukkit.plugin.Plugin;
 
 import java.io.IOException;
+import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
@@ -962,7 +963,8 @@ public int fastRemoveProtections(CommandSender sender, String where, boolean sho
         sender.sendMessage("Loading protections via STREAM mode");
 
         try {
-            Statement resultStatement = physicalDatabase.getConnection().createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
+            Connection connection = physicalDatabase.createConnection();
+            Statement resultStatement = connection.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
 
             if (physicalDatabase.getType() == Database.Type.MySQL) {
                 resultStatement.setFetchSize(Integer.MIN_VALUE);
@@ -1007,6 +1009,7 @@ public int fastRemoveProtections(CommandSender sender, String where, boolean sho
             // Close the streaming statement
             result.close();
             resultStatement.close();
+            connection.close();
 
             // flush all of the queries
             fullRemoveProtections(sender, toRemove);
@@ -1039,7 +1042,8 @@ private void fullRemoveProtections(CommandSender sender, List<Integer> toRemove)
         String prefix = getPhysicalDatabase().getPrefix();
 
         // create the statement to use
-        Statement statement = getPhysicalDatabase().getConnection().createStatement();
+        Connection connection = getPhysicalDatabase().createConnection();
+        Statement statement = connection.createStatement();
 
         while (iter.hasNext()) {
             int protectionId = iter.next();
@@ -1063,6 +1067,7 @@ private void fullRemoveProtections(CommandSender sender, List<Integer> toRemove)
         }
 
         statement.close();
+        connection.close();
     }
 
     /**
@@ -1420,7 +1425,7 @@ public void load() {
 
             physicalDatabase.load();
 
-            log("Using database: " + StringUtil.capitalizeFirstLetter(physicalDatabase.getConnection().getMetaData().getDriverVersion()));
+            log("Using database: " + physicalDatabase.getType().toString());
         } catch (Exception e) {
             e.printStackTrace();
         }

src/main/java/com/griefcraft/migration/DatabaseMigrator.java

@@ -47,8 +47,6 @@ public class DatabaseMigrator {
      */
     public boolean migrate(PhysDB fromDatabase, PhysDB toDatabase) {
         try {
-            toDatabase.getConnection().setAutoCommit(false);
-
             // some prelim data
             int startProtections = toDatabase.getProtectionCount();
             int protectionCount = fromDatabase.getProtectionCount();
@@ -63,7 +61,6 @@ public boolean migrate(PhysDB fromDatabase, PhysDB toDatabase) {
                     protection.saveNow();
                 }
 
-                toDatabase.getConnection().commit();
                 if (expectedProtections != (protectionCount = fromDatabase.getProtectionCount())) {
                     logger.info("Weird, only " + protectionCount + " protections are in the database? Continuing...");
                 }
@@ -80,9 +77,6 @@ public boolean migrate(PhysDB fromDatabase, PhysDB toDatabase) {
                     history.sync();
                 }
             }
-
-            fromDatabase.getConnection().close();
-            toDatabase.getConnection().setAutoCommit(true);
         } catch (Exception e) {
             e.printStackTrace();
             return false;

src/main/java/com/griefcraft/modules/admin/AdminCleanup.java

@@ -40,6 +40,7 @@
 import org.bukkit.command.CommandSender;
 import org.bukkit.scheduler.BukkitScheduler;
 
+import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
@@ -124,7 +125,8 @@ public void push(List<Integer> toRemove) throws SQLException {
             String prefix = lwc.getPhysicalDatabase().getPrefix();
 
             // create the statement to use
-            Statement statement = lwc.getPhysicalDatabase().getConnection().createStatement();
+            Connection connection = lwc.getPhysicalDatabase().createConnection();
+            Statement statement = connection.createStatement();
 
             while (iter.hasNext()) {
                 int protectionId = iter.next();
@@ -147,6 +149,7 @@ public void push(List<Integer> toRemove) throws SQLException {
             }
 
             statement.close();
+            connection.close();
         }
 
         public void run() {
@@ -173,7 +176,8 @@ public void run() {
                 database.connect();
                 database.load();
 
-                Statement resultStatement = database.getConnection().createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
+                Connection connection = database.createConnection();
+                Statement resultStatement = connection.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
 
                 if (lwc.getPhysicalDatabase().getType() == Database.Type.MySQL) {
                     resultStatement.setFetchSize(Integer.MIN_VALUE);
@@ -240,6 +244,7 @@ public Void call() throws Exception {
                 // close the sql statements
                 result.close();
                 resultStatement.close();
+                connection.close();
 
                 // flush all of the queries
                 push(toRemove);

src/main/java/com/griefcraft/modules/admin/AdminQuery.java

@@ -37,6 +37,7 @@
 import com.griefcraft.util.StringUtil;
 import org.bukkit.command.CommandSender;
 
+import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
@@ -68,14 +69,8 @@ public void onCommand(LWCCommandEvent event) {
         if (args[0].equals("query")) {
             String query = StringUtil.join(args, 1);
 
-            try {
-                Statement statement = lwc.getPhysicalDatabase().getConnection().createStatement();
-                statement.executeUpdate(query);
-                statement.close();
-                sender.sendMessage(Colors.Green + "Done.");
-            } catch (SQLException e) {
-                sender.sendMessage(Colors.Red + "Err: " + e.getMessage());
-            }
+            lwc.getPhysicalDatabase().executeUpdateNoException(query);
+            sender.sendMessage(Colors.Green + "Done.");
         }
 
         // Specific query, but the where statement is given
@@ -92,7 +87,8 @@ public void onCommand(LWCCommandEvent event) {
             // execute the query
             try {
                 PhysDB database = lwc.getPhysicalDatabase();
-                Statement statement = database.getConnection().createStatement();
+                Connection connection = database.createConnection();
+                Statement statement = connection.createStatement();
 
                 // choose the statement
                 if (args[0].startsWith("update")) {