add ConnectionPool.from(url), ConnectionPool.from(url, user, password…

…), ConnectionPool.from(url, properties), NonBlockingConnectionPool.Builder.user(user) and .password(password) #34

rxjava2-jdbc/src/main/java/org/davidmoten/rx/jdbc/ConnectionProvider.java

@@ -1,9 +1,14 @@
 package org.davidmoten.rx.jdbc;
 
 import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.util.Properties;
 
 import javax.annotation.Nonnull;
 
+import org.davidmoten.rx.jdbc.exceptions.SQLRuntimeException;
+
 import com.github.davidmoten.guavamini.Preconditions;
 
 /**
@@ -18,17 +23,26 @@ public interface ConnectionProvider {
      * 
      * @return a new Connection to a database
      */
-    @Nonnull 
+    @Nonnull
     Connection get();
 
     /**
      * Closes the connection provider and releases its resources. For example, a
-     * connection pool may need formal closure to release its connections
-     * because connection.close() is actually just releasing a connection back
-     * to the pool for reuse. This method should be idempotent.
+     * connection pool may need formal closure to release its connections because
+     * connection.close() is actually just releasing a connection back to the pool
+     * for reuse. This method should be idempotent.
      */
     void close();
 
+    /**
+     * Warning: Don't pass one of these as a ConnectionProvider to a pool because
+     * once the pool closes the connection the pool cannot create a new one (the
+     * same closed connection is returned). Instead use a different ConnectionProvider
+     * factory method.
+     * 
+     * @param connection connection for singleton provider
+     * @return singleton connection provider (don't use with connection pools!)
+     */
     static ConnectionProvider from(@Nonnull Connection connection) {
         Preconditions.checkNotNull(connection, "connection cannot be null");
         return new ConnectionProvider() {
@@ -45,4 +59,65 @@ public void close() {
         };
     }
 
+    static ConnectionProvider from(@Nonnull String url) {
+        Preconditions.checkNotNull(url, "url cannot be null");
+        return new ConnectionProvider() {
+
+            @Override
+            public Connection get() {
+                try {
+                    return DriverManager.getConnection(url);
+                } catch (SQLException e) {
+                    throw new SQLRuntimeException(e);
+                }
+            }
+
+            @Override
+            public void close() {
+                // do nothing as closure will be handle by pool
+            }
+        };
+    }
+
+    static ConnectionProvider from(@Nonnull String url, String username, String password) {
+        Preconditions.checkNotNull(url, "url cannot be null");
+        return new ConnectionProvider() {
+
+            @Override
+            public Connection get() {
+                try {
+                    return DriverManager.getConnection(url, username, password);
+                } catch (SQLException e) {
+                    throw new SQLRuntimeException(e);
+                }
+            }
+
+            @Override
+            public void close() {
+                // do nothing as closure will be handle by pool
+            }
+        };
+    }
+
+    static ConnectionProvider from(@Nonnull String url, Properties properties) {
+        Preconditions.checkNotNull(url, "url cannot be null");
+        Preconditions.checkNotNull(properties, "properties cannot be null");
+        return new ConnectionProvider() {
+
+            @Override
+            public Connection get() {
+                try {
+                    return DriverManager.getConnection(url, properties);
+                } catch (SQLException e) {
+                    throw new SQLRuntimeException(e);
+                }
+            }
+
+            @Override
+            public void close() {
+                // do nothing as closure will be handle by pool
+            }
+        };
+    }
+
 }

rxjava2-jdbc/src/main/java/org/davidmoten/rx/jdbc/pool/NonBlockingConnectionPool.java

@@ -95,6 +95,18 @@ public Builder<T> url(String url) {
             this.url = url;
             return this;
         }
+
+        public Builder<T> user(String user) {
+            properties.put("user", user);
+            return this;
+        }
+
+        public Builder<T> password(String password) {
+            properties.put("password", password);
+            return this;
+        }
+
+
 
         /**
          * Sets the JDBC properties that will be passed to