[jOOQ/jOOQ#9991] Offer an org.jooq.impl.AbstractBinding base implementation for the common case

jOOQ/src/main/java/org/jooq/impl/AbstractBinding.java

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+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Other licenses:
+ * -----------------------------------------------------------------------------
+ * Commercial licenses for this work are available. These replace the above
+ * ASL 2.0 and offer limited warranties, support, maintenance, and commercial
+ * database integrations.
+ *
+ * For more information, please visit: http://www.jooq.org/licenses
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ */
+package org.jooq.impl;
+
+import static org.jooq.conf.ParamType.INLINED;
+import static org.jooq.impl.Keywords.K_NULL;
+
+import java.sql.SQLData;
+import java.sql.SQLException;
+
+import org.jooq.Binding;
+import org.jooq.BindingGetSQLInputContext;
+import org.jooq.BindingGetStatementContext;
+import org.jooq.BindingRegisterContext;
+import org.jooq.BindingSQLContext;
+import org.jooq.BindingSetSQLOutputContext;
+import org.jooq.conf.ParamType;
+
+/**
+ * A convenient base implementation for custom bindings, simplifies the
+ * implementation.
+ * <p>
+ * The simplification is provided by offering empty implementations for rarely
+ * used methods, such as those for stored procedure OUT parameter support:
+ * <p>
+ * <ul>
+ * <li>{@link #register(BindingRegisterContext)} to register the OUT parameter.</li>
+ * <li>{@link #get(BindingGetStatementContext)} to read the OUT parameter.</li>
+ * </ul>
+ * <p>
+ * or {@link SQLData} serialisation support (e.g. for Oracle user defined types):
+ * <p>
+ * <ul>
+ * <li>{@link #set(BindingSetSQLOutputContext)} to serialise a user defined type.</li>
+ * <li>{@link #get(BindingGetSQLInputContext)} to read a user defined type.</li>
+ * </ul>
+ * <p>
+ *
+ * @author Lukas Eder
+ */
+@SuppressWarnings("unused")
+public abstract class AbstractBinding<T, U> implements Binding<T, U> {
+
+    /**
+     * Generated UID
+     */
+    private static final long serialVersionUID = 2172557061592118398L;
+
+    /**
+     * A convenient base implementation that handles the {@link ParamType}
+     * setting and delegates to {@link #sqlInline(BindingSQLContext)} or
+     * {@link #sqlBind(BindingSQLContext)} respectively.
+     */
+    @Override
+    public void sql(BindingSQLContext<U> ctx) throws SQLException {
+        if (ctx.render().paramType() == INLINED)
+            if (ctx.value() == null)
+                ctx.render().visit(K_NULL);
+            else
+                sqlInline(ctx);
+        else
+            sqlBind(ctx);
+    }
+
+    /**
+     * Generate the SQL string for inline values.
+     * <p>
+     * The default implementation generates a string literal representation of
+     * the user defined value. Custom implementations may want to override this.
+     */
+    protected void sqlInline(BindingSQLContext<U> ctx) throws SQLException {
+        ctx.render().visit(DSL.inline("" + ctx.value()));
+    }
+
+    /**
+     * Generate the SQL string for a bind variable placeholder.
+     * <p>
+     * In almost all cases, this can just be a "?" string. In some cases, the
+     * placeholder needs to be cast to a vendor specific data type, such as in
+     * PostgreSQL, "?::tsvector".
+     */
+    protected void sqlBind(BindingSQLContext<U> ctx) throws SQLException {
+        ctx.render().sql(ctx.variable());
+    }
+
+    // -------------------------------------------------------------------------
+    // Empty base implementations for stored procedure OUT parameter support:
+    // -------------------------------------------------------------------------
+
+    @Override
+    public void register(BindingRegisterContext<U> ctx) throws SQLException {}
+
+    @Override
+    public void get(BindingGetStatementContext<U> ctx) throws SQLException {}
+
+    // -------------------------------------------------------------------------
+    // Empty base implementations for SQLData serialisation support:
+    // -------------------------------------------------------------------------
+
+    @Override
+    public void set(BindingSetSQLOutputContext<U> ctx) throws SQLException {}
+
+    @Override
+    public void get(BindingGetSQLInputContext<U> ctx) throws SQLException {}
+}