From 54032be1c04e293fc20184517c5b7da8864596c8 Mon Sep 17 00:00:00 2001
From: Antonio Freire <antonio.freire@visma.com>
Date: Thu, 26 Apr 2018 12:25:55 +0100
Subject: [PATCH] Improvement: No database connection required

This merge request will add the ability to use this library with other frameworks, like Spring JDBC.
It will also allow its use with PreparedStatements.

Additional patches:
Using try-with-resources on SQL statements.
---
 .../jonathanhds/sqlbuilder/Context.java       | 20 +++++++++-----
 .../jonathanhds/sqlbuilder/Database.java      |  2 +-
 .../sqlbuilder/builder/QueryBuilder.java      |  4 +++
 .../sqlbuilder/select/SelectTest.java         | 26 ++++++++++++++++---
 4 files changed, 42 insertions(+), 10 deletions(-)

diff --git a/src/main/java/com/github/jonathanhds/sqlbuilder/Context.java b/src/main/java/com/github/jonathanhds/sqlbuilder/Context.java
index 59e4687..5c36557 100644
--- a/src/main/java/com/github/jonathanhds/sqlbuilder/Context.java
+++ b/src/main/java/com/github/jonathanhds/sqlbuilder/Context.java
@@ -44,6 +44,13 @@ public Context(Database database, Connection connection) {
 		parameters = new LinkedList<>();
 	}
 
+	public Context(Database database) {
+		this.database = database;
+		this.connection = null;
+		this.sql = new StringBuilder();
+		this.parameters = new LinkedList<>();
+	}
+
 	@Override
 	public String toString() {
 		return sql.toString();
@@ -111,14 +118,15 @@ private ResultSet execute(String sql) throws SQLException {
 	}
 
 	private PreparedStatement prepareStatement(String sql) throws SQLException {
-		PreparedStatement statement = connection.prepareStatement(sql);
+		try (PreparedStatement statement = connection.prepareStatement(sql)) {
 
-		int i = 1;
-		for (Object parameter : parameters) {
-			statement.setObject(i++, parameter);
-		}
+			int i = 1;
+			for (Object parameter : parameters) {
+				statement.setObject(i++, parameter);
+			}
 
-		return statement;
+			return statement;
+		}
 	}
 
 }
\ No newline at end of file
diff --git a/src/main/java/com/github/jonathanhds/sqlbuilder/Database.java b/src/main/java/com/github/jonathanhds/sqlbuilder/Database.java
index a62d162..8fa3f1a 100644
--- a/src/main/java/com/github/jonathanhds/sqlbuilder/Database.java
+++ b/src/main/java/com/github/jonathanhds/sqlbuilder/Database.java
@@ -1,5 +1,5 @@
 package com.github.jonathanhds.sqlbuilder;
 
 public enum Database {
-	ORACLE, HSQLDB
+	ORACLE, HSQLDB, NONE
 }
\ No newline at end of file
diff --git a/src/main/java/com/github/jonathanhds/sqlbuilder/builder/QueryBuilder.java b/src/main/java/com/github/jonathanhds/sqlbuilder/builder/QueryBuilder.java
index 4a2e94c..f06b775 100644
--- a/src/main/java/com/github/jonathanhds/sqlbuilder/builder/QueryBuilder.java
+++ b/src/main/java/com/github/jonathanhds/sqlbuilder/builder/QueryBuilder.java
@@ -23,6 +23,10 @@ public QueryBuilder(Database database, Connection connection) {
 		this.context = new Context(database, connection);
 	}
 
+	public QueryBuilder() {
+		this.context = new Context(Database.NONE);
+	}
+
 	public Select select() {
 		return new Select(context);
 	}
diff --git a/src/test/java/com/github/jonathanhds/sqlbuilder/select/SelectTest.java b/src/test/java/com/github/jonathanhds/sqlbuilder/select/SelectTest.java
index ae033b8..673a224 100644
--- a/src/test/java/com/github/jonathanhds/sqlbuilder/select/SelectTest.java
+++ b/src/test/java/com/github/jonathanhds/sqlbuilder/select/SelectTest.java
@@ -1,5 +1,6 @@
 package com.github.jonathanhds.sqlbuilder.select;
 
+import com.github.jonathanhds.sqlbuilder.builder.QueryBuilder;
 import com.github.jonathanhds.sqlbuilder.builder.QueryBuilderHSQLDB;
 import com.github.jonathanhds.sqlbuilder.builder.QueryBuilderOracle;
 import com.github.jonathanhds.sqlbuilder.support.*;
@@ -9,6 +10,7 @@
 
 import java.sql.Connection;
 import java.sql.SQLException;
+import java.sql.Statement;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.List;
@@ -16,6 +18,7 @@
 import static com.github.jonathanhds.sqlbuilder.select.OrderByType.DESC;
 import static java.util.Calendar.*;
 import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThat;
 
 public class SelectTest {
@@ -25,18 +28,33 @@ public class SelectTest {
 	@Before
 	public void startConnection() throws Exception {
 		connection = new MemoryDatabase().getConnection();
-		connection.createStatement().executeQuery("SET DATABASE SQL SYNTAX ORA FALSE");
+        try (Statement statement = connection.createStatement()) {
+            statement.executeQuery("SET DATABASE SQL SYNTAX ORA FALSE");
+        }
 	}
 
 	@After
 	public void closeConnection() throws Exception {
-		connection.createStatement().execute("SHUTDOWN");
+        try (Statement statement = connection.createStatement()) {
+            statement.execute("SHUTDOWN");
+        }
 
 		if (!connection.isClosed()) {
 			connection.close();
 		}
 	}
 
+	@Test
+	public void selectWithoutDatabase() {
+		String query = new QueryBuilder()
+				.select()
+				.all()
+				.from()
+				.table("User u")
+				.toString();
+		assertEquals(query, "SELECT\n*\nFROM\nUser u\n\n\n");
+	}
+
 	@Test
 	public void selectAllFromTable() throws Exception {
 		List<Person> persons = new QueryBuilderHSQLDB(connection).select()
@@ -332,7 +350,9 @@ public void selectColumnsFromTableGroupByHavingOrderBy() throws Exception {
 
 	@Test
 	public void selectAllFromTableWithPagination_Oracle() throws Exception {
-		connection.createStatement().executeQuery("SET DATABASE SQL SYNTAX ORA TRUE");
+        try (Statement statement = connection.createStatement()) {
+            statement.executeQuery("SET DATABASE SQL SYNTAX ORA TRUE");
+        }
 		List<Person> persons = new QueryBuilderOracle(connection).select()
 				.all()
 				.from()