mbean支持shrink

git-svn-id: http://code.alibabatech.com/svn/druid/trunk@541 b9813039-fb51-4c41-a8b9-e21c2acb5095

src/main/java/com/alibaba/druid/pool/DruidDataSource.java

@@ -743,9 +743,11 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
                             }
                         }
                         int removeCount = evictList.size();
-                        System.arraycopy(connections, removeCount, connections, 0, count - removeCount);
-                        Arrays.fill(connections, count - removeCount, count, null);
-                        count -= removeCount;
+                        if (removeCount > 0) {
+                            System.arraycopy(connections, removeCount, connections, 0, count - removeCount);
+                            Arrays.fill(connections, count - removeCount, count, null);
+                            count -= removeCount;
+                        }
                     } finally {
                         lock.unlock();
                     }
@@ -1128,6 +1130,32 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
 
     @Override
     public void shrink() {
-        throw new UnsupportedOperationException();
+        final List<ConnectionHolder> evictList = new ArrayList<ConnectionHolder>();
+        lock.lock();
+        try {
+            for (int i = 0; i < count; ++i) {
+                ConnectionHolder connection = connections[i];
+
+                if (count - evictList.size() <= minIdle) {
+                    break;
+                }
+
+                evictList.add(connection);
+            }
+            int removeCount = evictList.size();
+            if (removeCount > 0) {
+                System.arraycopy(connections, removeCount, connections, 0, count - removeCount);
+                Arrays.fill(connections, count - removeCount, count, null);
+                count -= removeCount;
+            }
+        } finally {
+            lock.unlock();
+        }
+        
+        for (ConnectionHolder item : evictList) {
+            Connection connection = item.getConnection();
+            JdbcUtils.close(connection);
+            destroyCount++;
+        }
     }
 }

src/test/java/com/alibaba/druid/pool/ui/DruidDataSourceUIManager.java

@@ -6,6 +6,7 @@ import java.awt.EventQueue;
 import java.awt.Toolkit;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
+import java.lang.management.ManagementFactory;
 import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -17,6 +18,10 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicInteger;
 
+import javax.management.InstanceNotFoundException;
+import javax.management.MBeanRegistrationException;
+import javax.management.MalformedObjectNameException;
+import javax.management.ObjectName;
 import javax.swing.JButton;
 import javax.swing.JFrame;
 import javax.swing.JLabel;
@@ -446,6 +451,12 @@ public class DruidDataSourceUIManager extends JFrame {
 
     public void closeDataSource_actionPerformed(ActionEvent e) {
         dataSource.close();
+        
+        try {
+            ManagementFactory.getPlatformMBeanServer().unregisterMBean(new ObjectName("com.alibaba.druid:type=DruidDataSource"));
+        } catch (Exception e1) {
+            e1.printStackTrace();
+        }
 
         txtUrl.setEnabled(true);
         txtDriverClass.setEnabled(true);
@@ -487,6 +498,8 @@ public class DruidDataSourceUIManager extends JFrame {
             
             dataSource.setTimeBetweenEvictionRunsMillis(60000);
             dataSource.setNumTestsPerEvictionRun(20);
+            
+            ManagementFactory.getPlatformMBeanServer().registerMBean(dataSource, new ObjectName("com.alibaba.druid:type=DruidDataSource"));
 
             try {
                 Connection conn = dataSource.getConnection();