Merge pull request #481 from zhenlineo/1.6-or-default

lutovich · web-flow · commit 7c5570d9d2dd · 2018-04-09T11:50:15.000+02:00
Add `Value#asXXX(defalutValue)` for primary types
diff --git a/driver/src/main/java/org/neo4j/driver/internal/value/ValueAdapter.java b/driver/src/main/java/org/neo4j/driver/internal/value/ValueAdapter.java
@@ -90,6 +90,42 @@ public String asString()
         throw new Uncoercible( type().name(), "Java String" );
     }
 
+    @Override
+    public boolean asBoolean( boolean defaultValue )
+    {
+        return computeOrDefault( Value:: asBoolean, defaultValue );
+    }
+
+    @Override
+    public String asString( String defaultValue )
+    {
+        return computeOrDefault( (Value::asString), defaultValue );
+    }
+
+    @Override
+    public long asLong( long defaultValue )
+    {
+        return computeOrDefault( Value::asLong, defaultValue );
+    }
+
+    @Override
+    public int asInt( int defaultValue )
+    {
+        return computeOrDefault( Value::asInt, defaultValue );
+    }
+
+    @Override
+    public double asDouble( double defaultValue )
+    {
+        return computeOrDefault( Value::asDouble, defaultValue );
+    }
+
+    @Override
+    public float asFloat( float defaultValue )
+    {
+        return computeOrDefault( Value::asFloat, defaultValue );
+    }
+
     @Override
     public long asLong()
     {
@@ -150,6 +186,88 @@ public Object asObject()
         throw new Uncoercible( type().name(), "Java Object" );
     }
 
+    @Override
+    public <T> T computeOrDefault( Function<Value,T> mapper, T defaultValue )
+    {
+        if ( isNull() )
+        {
+            return defaultValue;
+        }
+        return mapper.apply( this );
+    }
+
+    @Override
+    public Map<String,Object> asMap( Map<String,Object> defaultValue )
+    {
+        return computeOrDefault( Value::asMap, defaultValue );
+    }
+
+    @Override
+    public <T> Map<String,T> asMap( Function<Value,T> mapFunction, Map<String,T> defaultValue )
+    {
+        return computeOrDefault( value -> value.asMap( mapFunction ), defaultValue );
+    }
+
+    @Override
+    public byte[] asByteArray( byte[] defaultValue )
+    {
+        return computeOrDefault( Value::asByteArray, defaultValue );
+    }
+
+    @Override
+    public List<Object> asList( List<Object> defaultValue )
+    {
+        return computeOrDefault( Value::asList, defaultValue );
+    }
+
+    @Override
+    public <T> List<T> asList( Function<Value,T> mapFunction, List<T> defaultValue )
+    {
+        return computeOrDefault( value -> value.asList( mapFunction ), defaultValue );
+    }
+
+    @Override
+    public LocalDate asLocalDate( LocalDate defaultValue )
+    {
+        return computeOrDefault( Value::asLocalDate, defaultValue );
+    }
+
+    @Override
+    public OffsetTime asOffsetTime( OffsetTime defaultValue )
+    {
+        return computeOrDefault( Value::asOffsetTime, defaultValue );
+    }
+
+    @Override
+    public LocalTime asLocalTime( LocalTime defaultValue )
+    {
+        return computeOrDefault( Value::asLocalTime, defaultValue );
+    }
+
+    @Override
+    public LocalDateTime asLocalDateTime( LocalDateTime defaultValue )
+    {
+        return computeOrDefault( Value::asLocalDateTime, defaultValue );
+    }
+
+    @Override
+    public ZonedDateTime asZonedDateTime( ZonedDateTime defaultValue )
+    {
+        return computeOrDefault( Value::asZonedDateTime, defaultValue );
+    }
+
+    @Override
+    public IsoDuration asIsoDuration( IsoDuration defaultValue )
+    {
+        return computeOrDefault( Value::asIsoDuration, defaultValue );
+    }
+
+    @Override
+    public Point asPoint( Point defaultValue )
+    {
+        return computeOrDefault( Value::asPoint, defaultValue );
+    }
+
     @Override
     public byte[] asByteArray()
     {
diff --git a/driver/src/main/java/org/neo4j/driver/v1/Value.java b/driver/src/main/java/org/neo4j/driver/v1/Value.java
@@ -26,6 +26,7 @@
 import java.util.List;
 import java.util.Map;
 
+import org.neo4j.driver.internal.value.NullValue;
 import org.neo4j.driver.v1.exceptions.ClientException;
 import org.neo4j.driver.v1.exceptions.value.LossyCoercion;
 import org.neo4j.driver.v1.exceptions.value.Uncoercible;
@@ -194,24 +195,54 @@ public interface Value extends MapAccessor, MapAccessorWithDefaultValue
      */
     Object asObject();
 
+    /**
+     * Apply the mapping function on the value if the value is not a {@link NullValue}, or the default value if the value is a {@link NullValue}.
+     * @param mapper The mapping function defines how to map a {@link Value} to T.
+     * @param defaultValue the value to return if the value is a {@link NullValue}
+     * @param <T> The return type
+     * @return The value after applying the given mapping function or the default value if the value is {@link NullValue}.
+     */
+    <T>T computeOrDefault( Function<Value, T> mapper, T defaultValue );
+
     /**
      * @return the value as a Java boolean, if possible.
      * @throws Uncoercible if value types are incompatible.
      */
     boolean asBoolean();
 
+    /**
+     * @param defaultValue return this value if the value is a {@link NullValue}.
+     * @return the value as a Java boolean, if possible.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    boolean asBoolean( boolean defaultValue );
+
     /**
      *  @return the value as a Java byte array, if possible.
      *  @throws Uncoercible if value types are incompatible.
      */
     byte[] asByteArray();
 
+    /**
+     *  @param defaultValue default to this value if the original value is a {@link NullValue}
+     *  @return the value as a Java byte array, if possible.
+     *  @throws Uncoercible if value types are incompatible.
+     */
+    byte[] asByteArray( byte[] defaultValue );
+
     /**
      *  @return the value as a Java String, if possible.
      *  @throws Uncoercible if value types are incompatible.
      */
     String asString();
 
+    /**
+     * @param defaultValue return this value if the value is null.
+     * @return the value as a Java String, if possible
+     * @throws Uncoercible if value types are incompatible.
+     */
+    String asString( String defaultValue );
+
     /**
      * @return the value as a Java Number, if possible.
      * @throws Uncoercible if value types are incompatible.
@@ -227,6 +258,15 @@ public interface Value extends MapAccessor, MapAccessorWithDefaultValue
      */
     long asLong();
 
+    /**
+     * Returns a Java long if no precision is lost in the conversion.
+     * @param defaultValue return this default value if the value is a {@link NullValue}.
+     * @return the value as a Java long.
+     * @throws LossyCoercion if it is not possible to convert the value without loosing precision.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    long asLong( long defaultValue );
+
     /**
      * Returns a Java int if no precision is lost in the conversion.
      *
@@ -236,6 +276,15 @@ public interface Value extends MapAccessor, MapAccessorWithDefaultValue
      */
     int asInt();
 
+    /**
+     * Returns a Java int if no precision is lost in the conversion.
+     * @param defaultValue return this default value if the value is a {@link NullValue}.
+     * @return the value as a Java int.
+     * @throws LossyCoercion if it is not possible to convert the value without loosing precision.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    int asInt( int defaultValue );
+
     /**
      * Returns a Java double if no precision is lost in the conversion.
      *
@@ -245,6 +294,15 @@ public interface Value extends MapAccessor, MapAccessorWithDefaultValue
      */
     double asDouble();
 
+    /**
+     * Returns a Java double if no precision is lost in the conversion.
+     * @param defaultValue default to this value if the value is a {@link NullValue}.
+     * @return the value as a Java double.
+     * @throws LossyCoercion if it is not possible to convert the value without loosing precision.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    double asDouble( double defaultValue );
+
     /**
      * Returns a Java float if no precision is lost in the conversion.
      *
@@ -254,6 +312,15 @@ public interface Value extends MapAccessor, MapAccessorWithDefaultValue
      */
     float asFloat();
 
+    /**
+     * Returns a Java float if no precision is lost in the conversion.
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @return the value as a Java float.
+     * @throws LossyCoercion if it is not possible to convert the value without loosing precision.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    float asFloat( float defaultValue );
+
     /**
      * If the underlying type can be viewed as a list, returns a java list of
      * values, where each value has been converted using {@link #asObject()}.
@@ -263,14 +330,35 @@ public interface Value extends MapAccessor, MapAccessorWithDefaultValue
      */
     List<Object> asList();
 
+
+    /**
+     * If the underlying type can be viewed as a list, returns a java list of
+     * values, where each value has been converted using {@link #asObject()}.
+     *
+     * @see #asObject()
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @return the value as a Java list of values, if possible
+     */
+    List<Object> asList( List<Object> defaultValue );
+
     /**
      * @param mapFunction a function to map from Value to T. See {@link Values} for some predefined functions, such
      * as {@link Values#ofBoolean()}, {@link Values#ofList(Function)}.
      * @param <T> the type of target list elements
      * @see Values for a long list of built-in conversion functions
      * @return the value as a list of T obtained by mapping from the list elements, if possible
      */
-    <T> List<T> asList( Function<Value, T> mapFunction );
+    <T> List<T> asList( Function<Value,T> mapFunction );
+
+    /**
+     * @param mapFunction a function to map from Value to T. See {@link Values} for some predefined functions, such
+     * as {@link Values#ofBoolean()}, {@link Values#ofList(Function)}.
+     * @param <T> the type of target list elements
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @see Values for a long list of built-in conversion functions
+     * @return the value as a list of T obtained by mapping from the list elements, if possible
+     */
+    <T> List<T> asList( Function<Value,T> mapFunction, List<T> defaultValue );
 
     /**
      * @return the value as a {@link Entity}, if possible.
@@ -338,6 +426,76 @@ public interface Value extends MapAccessor, MapAccessorWithDefaultValue
      */
     Point asPoint();
 
+    /**
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @return the value as a {@link LocalDate}, if possible.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    LocalDate asLocalDate( LocalDate defaultValue );
+
+    /**
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @return the value as a {@link OffsetTime}, if possible.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    OffsetTime asOffsetTime( OffsetTime defaultValue );
+
+    /**
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @return the value as a {@link LocalTime}, if possible.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    LocalTime asLocalTime( LocalTime defaultValue );
+
+    /**
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @return the value as a {@link LocalDateTime}, if possible.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    LocalDateTime asLocalDateTime( LocalDateTime defaultValue );
+
+    /**
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @return the value as a {@link ZonedDateTime}, if possible.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    ZonedDateTime asZonedDateTime( ZonedDateTime defaultValue );
+
+    /**
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @return the value as a {@link IsoDuration}, if possible.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    IsoDuration asIsoDuration( IsoDuration defaultValue );
+
+    /**
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @return the value as a {@link Point}, if possible.
+     * @throws Uncoercible if value types are incompatible.
+     */
+    Point asPoint( Point defaultValue );
+
+    /**
+     * Return as a map of string keys and values converted using
+     * {@link Value#asObject()}.
+     *
+     * This is equivalent to calling {@link #asMap(Function, Map)} with {@link Values#ofObject()}.
+     *
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @return the value as a Java map
+     */
+    Map<String, Object> asMap( Map<String,Object> defaultValue );
+
+    /**
+     * @param mapFunction a function to map from Value to T. See {@link Values} for some predefined functions, such
+     * as {@link Values#ofBoolean()}, {@link Values#ofList(Function)}.
+     * @param <T> the type of map values
+     * @param defaultValue default to this value if the value is a {@link NullValue}
+     * @see Values for a long list of built-in conversion functions
+     * @return the value as a map from string keys to values of type T obtained from mapping he original map values, if possible
+     */
+    <T> Map<String, T> asMap( Function<Value, T> mapFunction, Map<String, T> defaultValue );
+
     @Override
     boolean equals( Object other );
 
diff --git a/driver/src/test/java/org/neo4j/driver/internal/value/NullValueTest.java b/driver/src/test/java/org/neo4j/driver/internal/value/NullValueTest.java
