added parameter bind logging

[closes #278][#309]

Author: Kirill Marchuk

README.md

@@ -480,6 +480,7 @@ Logging facilities:
 
 * Driver Logging (`io.r2dbc.postgresql`)
 * Query Logging (`io.r2dbc.postgresql.QUERY` on `DEBUG` level)
+* Parameters' values Logging (`io.r2dbc.postgresql.PARAM` on `DEBUG` level)
 * Transport Logging (`io.r2dbc.postgresql.client`)
     * `DEBUG` enables `Message` exchange logging
     * `TRACE` enables traffic logging

src/main/java/io/r2dbc/postgresql/BindingLogger.java

@@ -0,0 +1,20 @@
+package io.r2dbc.postgresql;
+
+import reactor.util.Logger;
+import reactor.util.Loggers;
+
+/**
+ * Binding logger to log parameter bindings
+ */
+final class BindingLogger {
+
+    private static final Logger BINDING_LOGGER = Loggers.getLogger("io.r2dbc.postgresql.PARAM");
+
+    static void logBinding(int index, String bindValue) {
+        BINDING_LOGGER.debug("Parameter {} value bound: {}", index, bindValue);
+    }
+
+    static void logBinding(String name, String bindValue) {
+        BINDING_LOGGER.debug("Parameter {} value bound: {}", name, bindValue);
+    }
+}

src/main/java/io/r2dbc/postgresql/ExtendedQueryPostgresqlStatement.java

@@ -31,6 +31,7 @@
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Objects;
 import java.util.Set;
 import java.util.function.Predicate;
 import java.util.regex.Matcher;
@@ -74,13 +75,15 @@ public ExtendedQueryPostgresqlStatement bind(String identifier, Object value) {
         Assert.requireNonNull(identifier, "identifier must not be null");
         Assert.requireType(identifier, String.class, "identifier must be a String");
 
+        BindingLogger.logBinding(identifier, Objects.toString(value));
         return bind(getIndex(identifier), value);
     }
 
     @Override
     public ExtendedQueryPostgresqlStatement bind(int index, Object value) {
         Assert.requireNonNull(value, "value must not be null");
 
+        BindingLogger.logBinding(index, Objects.toString(value));
         this.bindings.getCurrent().add(index, this.context.getCodecs().encode(value));
 
         return this;
@@ -92,6 +95,7 @@ public ExtendedQueryPostgresqlStatement bindNull(String identifier, Class<?> typ
         Assert.requireType(identifier, String.class, "identifier must be a String");
         Assert.requireNonNull(type, "type must not be null");
 
+        BindingLogger.logBinding(identifier, "null of type " + type.getName());
         bindNull(getIndex(identifier), type);
         return this;
     }
@@ -100,6 +104,7 @@ public ExtendedQueryPostgresqlStatement bindNull(String identifier, Class<?> typ
     public ExtendedQueryPostgresqlStatement bindNull(int index, Class<?> type) {
         Assert.requireNonNull(type, "type must not be null");
 
+        BindingLogger.logBinding(index, "null of type " + type.getName());
         this.bindings.getCurrent().add(index, this.context.getCodecs().encodeNull(type));
         return this;
     }