use SPI for dialect initialization

Author: alexradzin

build.gradle

@@ -31,12 +31,12 @@ dependencies {
     testCompile group: 'junit', name: 'junit', version: '4.12'
     implementation 'com.upsolver:data-sources-interfaces:1.0.6'
 
-    compileOnly group: 'com.amazon.redshift', name: 'redshift-jdbc42', version: '1.2.1.1001'
-    compileOnly "mysql:mysql-connector-java:8.0.14"
-    compileOnly "com.oracle.ojdbc:ojdbc8:19.3.0.0"
-    compileOnly "net.snowflake:snowflake-jdbc:3.12.2"
-    compileOnly "org.postgresql:postgresql:42.2.9"
-    compileOnly "com.microsoft.sqlserver:mssql-jdbc:8.2.0.jre11"
+    implementation group: 'com.amazon.redshift', name: 'redshift-jdbc42', version: '1.2.1.1001'
+    implementation "mysql:mysql-connector-java:8.0.14"
+    implementation "com.oracle.ojdbc:ojdbc8:19.3.0.0"
+    implementation "net.snowflake:snowflake-jdbc:3.12.2"
+    implementation "org.postgresql:postgresql:42.2.9"
+    implementation "com.microsoft.sqlserver:mssql-jdbc:8.2.0.jre11"
 
 //    implementation fileTree(dir: '/tmp/p/com/upsolver/data-sources-interfaces/1.0.1/', include: '*.jar')
 }

src/main/java/com/upsolver/datasources/jdbc/querybuilders/DefaultQueryDialect.java

@@ -264,4 +264,9 @@ public String getDriverClassName() {
     public ThrowingBiFunction<ResultSet, Integer, String, SQLException> getStringValueGetter(int sqlType) {
         return valueGetters.getOrDefault(sqlType, getString);
     }
+
+    @Override
+    public boolean acceptsURL(String url) {
+        return url.startsWith("jdbc:");
+    }
 }

src/main/java/com/upsolver/datasources/jdbc/querybuilders/OracleQueryDialect.java

@@ -96,4 +96,9 @@ public SQLType getJdbcType(SQLType sqlType) {
         }
         return sqlType;
     }
+
+    @Override
+    public boolean acceptsURL(String url) {
+        return url.startsWith("jdbc:oracle:");
+    }
 }

src/main/java/com/upsolver/datasources/jdbc/querybuilders/PostgreSqlQueryDialect.java

@@ -23,4 +23,9 @@ public boolean isAutoIncrementColumn(ResultSet columnsResultSet) throws SQLExcep
     public String getDriverClassName() {
         return "org.postgresql.Driver";
     }
+
+    @Override
+    public boolean acceptsURL(String url) {
+        return url.startsWith("jdbc:postgresql:");
+    }
 }

src/main/java/com/upsolver/datasources/jdbc/querybuilders/QueryDialect.java

@@ -71,4 +71,6 @@ NamedPreparedStatment queryFullTable(TableInfo tableInfo,
     String getDriverClassName();
 
     ThrowingBiFunction<ResultSet, Integer, String, SQLException> getStringValueGetter(int sqlType);
+
+    boolean acceptsURL(String url);
 }

src/main/java/com/upsolver/datasources/jdbc/querybuilders/QueryDialectProvider.java

@@ -1,21 +1,15 @@
 package com.upsolver.datasources.jdbc.querybuilders;
 
-public class QueryDialectProvider {
+import java.util.ServiceLoader;
+import java.util.stream.StreamSupport;
 
+public class QueryDialectProvider {
     public static QueryDialect forConnection(String connectionString) {
         String connStr = connectionString.toLowerCase();
-        if (connStr.startsWith("jdbc:sqlserver")) {
-            return new SqlServerQueryDialect();
-        } else if (connStr.startsWith("jdbc:oracle")) {
-            return new OracleQueryDialect();
-        } else if (connStr.startsWith("jdbc:redshift")) {
-            return new RedshiftQueryDialect();
-        } else if (connStr.startsWith("jdbc:postgresql")) {
-            return new PostgreSqlQueryDialect();
-        } else if (connStr.startsWith("jdbc:snowflake")) {
-            return new SnowflakeQueryDialect();
-        }
-        return new DefaultQueryDialect();
-
+        Iterable<QueryDialect> iterable = () -> ServiceLoader.load(QueryDialect.class).iterator();
+        return StreamSupport.stream(iterable.spliterator(), false)
+                .filter(d -> d.acceptsURL(connStr))
+                .findFirst()
+                .orElseGet(DefaultQueryDialect::new);
     }
 }

src/main/java/com/upsolver/datasources/jdbc/querybuilders/RedshiftQueryDialect.java

@@ -18,4 +18,9 @@ public boolean isAutoIncrementColumn(ResultSet columnsResultSet) throws SQLExcep
         // Example default value: "identity"(707455, 0, '1,1'::text)
         return def != null && def.startsWith("\"identity\"(");
     }
+
+    @Override
+    public boolean acceptsURL(String url) {
+        return url.startsWith("jdbc:redshift:");
+    }
 }

src/main/java/com/upsolver/datasources/jdbc/querybuilders/SnowflakeQueryDialect.java

@@ -15,4 +15,9 @@ public long utcOffsetSeconds(Connection connection) throws SQLException {
     public boolean requiresUppercaseNames() {
         return true;
     }
+
+    @Override
+    public boolean acceptsURL(String url) {
+        return url.startsWith("jdbc:snowflake:");
+    }
 }

src/main/java/com/upsolver/datasources/jdbc/querybuilders/SqlServerQueryDialect.java

@@ -57,4 +57,9 @@ private static int getIntValue(Field field) {
             throw new IllegalStateException(e);
         }
     }
+
+    @Override
+    public boolean acceptsURL(String url) {
+        return url.startsWith("jdbc:sqlserver:");
+    }
 }

src/main/resources/META-INF/services/com.upsolver.datasources.jdbc.querybuilders.QueryDialect

@@ -0,0 +1,6 @@
+com.upsolver.datasources.jdbc.querybuilders.SqlServerQueryDialect
+com.upsolver.datasources.jdbc.querybuilders.OracleQueryDialect
+com.upsolver.datasources.jdbc.querybuilders.RedshiftQueryDialect
+com.upsolver.datasources.jdbc.querybuilders.PostgreSqlQueryDialect
+com.upsolver.datasources.jdbc.querybuilders.SnowflakeQueryDialect
+com.upsolver.datasources.jdbc.querybuilders.DefaultQueryDialect