refactor getProductDataBaseName

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/api/ShardingDataSource.java

@@ -28,8 +28,11 @@ import com.dangdang.ddframe.rdb.sharding.metrics.MetricsContext;
 import com.dangdang.ddframe.rdb.sharding.router.SQLRouteEngine;
 import com.google.common.base.Preconditions;
 
+import javax.sql.DataSource;
 import java.sql.Connection;
 import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Properties;
 
 /**
@@ -39,10 +42,10 @@ import java.util.Properties;
  */
 public class ShardingDataSource extends AbstractDataSourceAdapter {
     
-    private final ShardingContext shardingContext;
-    
     private final ShardingProperties shardingProperties;
     
+    private final ShardingContext shardingContext;
+    
     public ShardingDataSource(final ShardingRule shardingRule) {
         this(shardingRule, new Properties());
     }
@@ -51,13 +54,27 @@ public class ShardingDataSource extends AbstractDataSourceAdapter {
         Preconditions.checkNotNull(shardingRule);
         Preconditions.checkNotNull(props);
         shardingProperties = new ShardingProperties(props);
-        DatabaseType type;
         try {
-            type = DatabaseType.valueFrom(ShardingConnection.getDatabaseMetaDataFromDataSource(shardingRule.getDataSourceRule().getDataSources()).getDatabaseProductName());
-        } catch (final SQLException ex) {
-            throw new ShardingJdbcException("Can not get database product name", ex);
+            shardingContext = new ShardingContext(shardingRule, new SQLRouteEngine(shardingRule, DatabaseType.valueFrom(getDatabaseProductName(shardingRule))), new ExecutorEngine(shardingProperties));
+        } catch (SQLException ex) {
+            throw new ShardingJdbcException(ex);
+        }
+    }
+    
+    private String getDatabaseProductName(final ShardingRule shardingRule) throws SQLException {
+        String result = null;
+        Collection<Connection> connections = new ArrayList<>(shardingRule.getDataSourceRule().getDataSources().size());
+        for (DataSource each : shardingRule.getDataSourceRule().getDataSources()) {
+            Connection connection = each.getConnection();
+            connections.add(connection);
+            String databaseProductName = connection.getMetaData().getDatabaseProductName();
+            Preconditions.checkState(null == result || result.equals(databaseProductName), String.format("Database type inconsistent with '%s' and '%s'", result, databaseProductName));
+            result = databaseProductName;
+        }
+        for (Connection each : connections) {
+            each.close();
         }
-        shardingContext = new ShardingContext(shardingRule, new SQLRouteEngine(shardingRule, type), new ExecutorEngine(shardingProperties));
+        return result;
     }
     
     @Override

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/jdbc/ShardingConnection.java

@@ -17,30 +17,24 @@
 
 package com.dangdang.ddframe.rdb.sharding.jdbc;
 
-import java.sql.Connection;
-import java.sql.DatabaseMetaData;
-import java.sql.PreparedStatement;
-import java.sql.SQLException;
-import java.sql.Statement;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Map;
-import javax.sql.DataSource;
-
 import com.codahale.metrics.Timer.Context;
 import com.dangdang.ddframe.rdb.sharding.api.rule.DataSourceRule;
-import com.dangdang.ddframe.rdb.sharding.exception.ShardingJdbcException;
 import com.dangdang.ddframe.rdb.sharding.jdbc.adapter.AbstractConnectionAdapter;
 import com.dangdang.ddframe.rdb.sharding.metrics.MetricsContext;
-import com.google.common.base.Function;
 import com.google.common.base.Joiner;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.Collections2;
-import com.google.common.collect.Lists;
 import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 
+import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
 /**
  * 支持分片的数据库连接.
  * 
@@ -77,61 +71,10 @@ public final class ShardingConnection extends AbstractConnectionAdapter {
     public DatabaseMetaData getMetaData() throws SQLException {
         if (connectionMap.isEmpty()) {
             DataSourceRule dataSourceRule = shardingContext.getShardingRule().getDataSourceRule();
-            String dsName = dataSourceRule.getDataSourceNames().iterator().next();
-            connectionMap.put(dsName, dataSourceRule.getDataSource(dsName).getConnection());
-        }
-        return getDatabaseMetaDataFromConnection(connectionMap.values().iterator().next());
-    }
-    
-    public static DatabaseMetaData getDatabaseMetaDataFromDataSource(final Collection<DataSource> dataSources) {
-        Collection<Connection> connections = null;
-        try {
-            connections = Collections2.transform(dataSources, new Function<DataSource, Connection>() {
-                
-                @Override
-                public Connection apply(final DataSource input) {
-                    try {
-                        return input.getConnection();
-                    } catch (final SQLException ex) {
-                        throw new ShardingJdbcException(ex);
-                    }
-                }
-            });
-            return getDatabaseMetaDataFromConnection(connections);
-        } finally {
-            if (null != connections) {
-                for (Connection each : connections) {
-                    try {
-                        each.close();
-                    } catch (final SQLException ignored) {
-                    }
-                }
-            }
-        }
-    }
-    
-    private static DatabaseMetaData getDatabaseMetaDataFromConnection(final Connection connection) {
-        return getDatabaseMetaDataFromConnection(Lists.newArrayList(connection));
-    }
-    
-    private static DatabaseMetaData getDatabaseMetaDataFromConnection(final Collection<Connection> connections) {
-        String databaseProductName = null;
-        DatabaseMetaData result = null;
-        for (Connection each : connections) {
-            String databaseProductNameInEach;
-            DatabaseMetaData metaDataInEach;
-            try {
-                metaDataInEach = each.getMetaData();
-                databaseProductNameInEach = metaDataInEach.getDatabaseProductName();
-            } catch (final SQLException ex) {
-                throw new ShardingJdbcException("Can not get data source DatabaseProductName", ex);
-            }
-            Preconditions.checkState(null == databaseProductName || databaseProductName.equals(databaseProductNameInEach),
-                    String.format("Database type inconsistent with '%s' and '%s'", databaseProductName, databaseProductNameInEach));
-            databaseProductName = databaseProductNameInEach;
-            result = metaDataInEach;
+            String dataSourceName = dataSourceRule.getDataSourceNames().iterator().next();
+            connectionMap.put(dataSourceName, dataSourceRule.getDataSource(dataSourceName).getConnection());
         }
-        return result;
+        return connectionMap.values().iterator().next().getMetaData();
     }
     
     @Override