add dynamic support

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

@@ -55,8 +55,11 @@ public final class ConnectionHolder {
     private int                                 underlyingHoldability;
     private int                                 underlyingTransactionIsolation;
     private boolean                             underlyingAutoCommit;
+    private final int                           modCount;
 
     public ConnectionHolder(DruidAbstractDataSource dataSource, Connection conn) throws SQLException{
+        this.modCount = dataSource.getModCount();
+
         this.dataSource = dataSource;
         this.conn = conn;
         this.connecttimeMillis = System.currentTimeMillis();
@@ -75,6 +78,10 @@ public final class ConnectionHolder {
         statementPool = null;
     }
 
+    public int getModCount() {
+        return modCount;
+    }
+
     public boolean isUnderlyingReadOnly() {
         return underlyingReadOnly;
     }
@@ -143,10 +150,10 @@ public final class ConnectionHolder {
     }
 
     public boolean isPoolPreparedStatements() {
-//        if (dataSource.isOracle()) {
-//            return false;
-//        }
-        
+        // if (dataSource.isOracle()) {
+        // return false;
+        // }
+
         boolean poolPreparedStatements = dataSource.isPoolPreparedStatements();
         if (poolPreparedStatements) {
             boolean transaction = !isUnderlyingAutoCommit();

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

@@ -37,6 +37,7 @@ import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Logger;
 
 import javax.management.JMException;
@@ -213,10 +214,18 @@ public abstract class DruidAbstractDataSource extends WrapperAdapter implements
 
     protected boolean                                                                           useOracleImplicitCache                    = true;
 
+    protected final ReentrantLock                                                               lock                                      = new ReentrantLock();
+
+    protected int                                                                               modCount                                  = 0;
+
     public boolean isOracle() {
         return isOracle;
     }
 
+    protected int getModCount() {
+        return modCount;
+    }
+
     public void setOracle(boolean isOracle) {
         if (inited) {
             throw new IllegalStateException();
@@ -832,11 +841,39 @@ public abstract class DruidAbstractDataSource extends WrapperAdapter implements
     }
 
     public void setUsername(String user) {
-        if (inited) {
-            throw new UnsupportedOperationException();
-        }
+        lock.lock();
+        try {
+            if (equals(this.username, user)) {
+                return;
+            }
 
-        this.username = user;
+            if (inited) {
+                this.modCount++;
+                clear();
+            }
+
+            this.username = user;
+        } finally {
+            lock.unlock();
+        }
+    }
+    
+    public void setUrlAndUserAndPassword(String url, String user, String password) {
+        lock.lock();
+        try {
+            if (equals(this.jdbcUrl, url) && equals(this.username, user) && equals(this.password, password)) {
+                return;
+            }
+
+            if (inited) {
+                this.modCount++;
+                clear();
+            }
+
+            this.username = user;
+        } finally {
+            lock.unlock();
+        }
     }
 
     public String getPassword() {
@@ -844,11 +881,21 @@ public abstract class DruidAbstractDataSource extends WrapperAdapter implements
     }
 
     public void setPassword(String password) {
-        if (inited) {
-            throw new UnsupportedOperationException();
-        }
+        lock.lock();
+        try {
+            if (equals(this.password, password)) {
+                return;
+            }
 
-        this.password = password;
+            if (inited) {
+                this.modCount++;
+                clear();
+            }
+
+            this.password = password;
+        } finally {
+            lock.unlock();
+        }
     }
 
     public Properties getConnectProperties() {
@@ -901,12 +948,24 @@ public abstract class DruidAbstractDataSource extends WrapperAdapter implements
     }
 
     public void setUrl(String jdbcUrl) {
-        if (inited) {
-            throw new UnsupportedOperationException();
-        }
+        lock.lock();
+        try {
+            if (equals(this.jdbcUrl, jdbcUrl)) {
+                return;
+            }
 
-        this.jdbcUrl = jdbcUrl;
+            if (inited) {
+                this.modCount++;
+                clear();
+            }
+
+            this.jdbcUrl = jdbcUrl;
+        } finally {
+            lock.unlock();
+        }
     }
+    
+    public abstract void clear();
 
     public String getDriverClassName() {
         return driverClass;
@@ -1532,4 +1591,14 @@ public abstract class DruidAbstractDataSource extends WrapperAdapter implements
 
         JdbcUtils.close(stmtHolder.getStatement());
     }
+    
+    public static boolean equals(Object object1, Object object2) {
+        if (object1 == object2) {
+            return true;
+        }
+        if ((object1 == null) || (object2 == null)) {
+            return false;
+        }
+        return object1.equals(object2);
+    }
 }

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

@@ -28,7 +28,6 @@ import java.util.Properties;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.Condition;
-import java.util.concurrent.locks.ReentrantLock;
 
 import javax.naming.NamingException;
 import javax.naming.Reference;
@@ -67,8 +66,6 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
 
     private static final long       serialVersionUID        = 1L;
 
-    private final ReentrantLock     lock                    = new ReentrantLock();
-
     private final Condition         notEmpty                = lock.newCondition();
     private final Condition         empty                   = lock.newCondition();
 
@@ -295,7 +292,7 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
                     throw new SQLException("not support oracle driver " + driver.getMajorVersion() + "."
                                            + driver.getMinorVersion());
                 }
-                
+
                 if (driver.getMajorVersion() == 10 && isUseOracleImplicitCache()) {
                     this.getConnectProperties().setProperty("oracle.jdbc.FreeMemoryOnEnterImplicitCache", "true");
                 }
@@ -605,17 +602,29 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
                 }
             }
 
+            boolean neadDestory = false;
             lock.lockInterruptibly();
             try {
-                activeCount--;
-                closeCount++;
+                if (holder.getModCount() == this.modCount) {
+                    activeCount--;
+                    closeCount++;
 
-                // 第六步，加入队列中(putLast)
-                putLast(holder);
-                recycleCount++;
+                    // 第六步，加入队列中(putLast)
+                    putLast(holder);
+                    recycleCount++;
+                } else {
+                    destroyCount++;
+                    activeCount--;
+                    closeCount++;
+                    neadDestory = true;
+                }
             } finally {
                 lock.unlock();
             }
+
+            if (neadDestory) {
+                JdbcUtils.close(conn);
+            }
         } catch (Throwable e) {
             JdbcUtils.close(conn);
 
@@ -657,7 +666,7 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
             if (this.closed) {
                 return;
             }
-            
+
             if (!this.inited) {
                 return;
             }
@@ -685,9 +694,9 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
             enable = false;
             notEmpty.signalAll();
             notEmptySignalCount++;
-            
+
             this.closed = true;
-            
+
             for (Filter filter : filters) {
                 filter.destory();
             }
@@ -1176,6 +1185,28 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
         }
     }
 
+    public void clear() {
+        final List<ConnectionHolder> evictList = new ArrayList<ConnectionHolder>();
+
+        lock.lock();
+        try {
+            for (int i = 0; i < poolingCount; ++i) {
+                ConnectionHolder connection = connections[i];
+                evictList.add(connection);
+            }
+
+            poolingCount = 0;
+        } finally {
+            lock.unlock();
+        }
+
+        for (ConnectionHolder item : evictList) {
+            Connection connection = item.getConnection();
+            JdbcUtils.close(connection);
+            destroyCount++;
+        }
+    }
+
     public int getWaitThreadCount() {
         lock.lock();
         try {