[DMR-12] Add asXXXOrNull methods to return null from undefined nodes

src/main/java/org/jboss/dmr/ModelNode.java

@@ -238,6 +238,19 @@ public long asLong(final long defVal) {
         return value.asLong(defVal);
     }
 
+    /**
+     * Get the value of this node as a {@code Long}, or {@code null} if this node is not {@link #isDefined() defined}.
+     * Collection types will return the size of the collection for this value.  Other types may attempt a string conversion.
+     *
+     * @return the long value or {@code null}
+     *
+     * @throws NumberFormatException if this node's {@link #getType() type} is {@link ModelType#STRING} and a numeric conversion of the string value is not possible
+     * @throws IllegalArgumentException if this node's {@link #getType() type} is one where no numeric conversion is possible
+     */
+    public Long asLongOrNull() {
+        return isDefined() ? asLong() : null;
+    }
+
     /**
      * Get the value of this node as an {@code int}.  Collection types will return the size
      * of the collection for this value.  Other types may attempt a string conversion.
@@ -263,6 +276,17 @@ public int asInt(final int defVal) {
         return value.asInt(defVal);
     }
 
+    /**
+     * Get the value of this node as an {@code int}, or {@code null} if this node is not {@link #isDefined() defined}.
+     * Collection types will return the size of the collection for this value.  Other types may attempt a string conversion.
+     *
+     * @return the int value or {@code null}
+     * @throws IllegalArgumentException if no conversion is possible
+     */
+    public Integer asIntOrNull() {
+        return isDefined() ? asInt() : null;
+    }
+
     /**
      * Get the value of this node as a {@code boolean}.  Collection types return {@code true} for non-empty
      * collections.  Numerical types return {@code true} for non-zero values.
@@ -287,6 +311,18 @@ public boolean asBoolean(final boolean defVal) {
         return value.asBoolean(defVal);
     }
 
+
+    /**
+     * Get the value of this node as a {@code boolean}, or {@code null} if this node is not {@link #isDefined() defined}.
+     * Collection types return {@code true} for non-empty collections.  Numerical types return {@code true} for non-zero values.
+     *
+     * @return the boolean value or {@code null}
+     * @throws IllegalArgumentException if no conversion is possible
+     */
+    public Boolean asBooleanOrNull() throws IllegalArgumentException {
+        return isDefined() ? value.asBoolean() : null;
+    }
+
     /**
      * Get the value as a string.  This is the literal value of this model node.  More than one node type may
      * yield the same value for this method.
@@ -308,6 +344,16 @@ public String asString(String defVal) {
         return isDefined() ? value.asString() : defVal;
     }
 
+    /**
+     * Get the value as a string or {@code null} if this node is not {@link #isDefined() defined}.  This is the literal value of this model node.  More than one node type may
+     * yield the same value for this method.
+     *
+     * @return the string value or {@code null}
+     */
+    public String asStringOrNull() {
+        return isDefined() ? value.asString() : null;
+    }
+
     /**
      * Get the value of this node as a {@code double}.  Collection types will return the size
      * of the collection for this value.  Other types may attempt a string conversion.
@@ -333,6 +379,17 @@ public double asDouble(final double defVal) {
         return value.asDouble(defVal);
     }
 
+    /**
+     * Get the value of this node as a {@code double} or {@code null} if this node is not {@link #isDefined() defined}.
+     * Collection types will return the size of the collection for this value.  Other types may attempt a string conversion.
+     *
+     * @return the double value or {@code null}
+     * @throws IllegalArgumentException if no conversion is possible
+     */
+    public Double asDoubleOrNull() throws IllegalArgumentException {
+        return isDefined() ? value.asDouble() : null;
+    }
+
     /**
      * Get the value of this node as a type, expressed using the {@code ModelType} enum.  The string
      * value of this node must be convertible to a type.
@@ -345,7 +402,7 @@ public ModelType asType() throws IllegalArgumentException {
     }
 
     /**
-     * Get the value of this node as a {@code BigDecimal}.  Collection types will return the size
+     * Get the value of this node as a {@code BigDecimal}. Collection types will return the size
      * of the collection for this value.  Other types may attempt a string conversion.
      *
      * @return the {@code BigDecimal} value
@@ -355,6 +412,17 @@ public BigDecimal asBigDecimal() throws IllegalArgumentException {
         return value.asBigDecimal();
     }
 
+    /**
+     * Get the value of this node as a {@code BigDecimal} or {@code null} if this node is not {@link #isDefined() defined}.
+     * Collection types will return the size of the collection for this value.  Other types may attempt a string conversion.
+     *
+     * @return the {@code BigDecimal} value or {@code null}
+     * @throws IllegalArgumentException if no conversion is possible
+     */
+    public BigDecimal asBigDecimalOrNull() throws IllegalArgumentException {
+        return isDefined() ? value.asBigDecimal() : null;
+    }
+
     /**
      * Get the value of this node as a {@code BigInteger}.  Collection types will return the size
      * of the collection for this value.  Other types may attempt a string conversion.
@@ -366,6 +434,17 @@ public BigInteger asBigInteger() throws IllegalArgumentException {
         return value.asBigInteger();
     }
 
+    /**
+     * Get the value of this node as a {@code BigInteger} or {@code null} if this node is not {@link #isDefined() defined}.
+     * Collection types will return the size of the collection for this value.  Other types may attempt a string conversion.
+     *
+     * @return the {@code BigInteger} value or {@code null}
+     * @throws IllegalArgumentException if no conversion is possible
+     */
+    public BigInteger asBigIntegerOrNull() throws IllegalArgumentException {
+        return isDefined() ? value.asBigInteger() : null;
+    }
+
     /**
      * Get the value of this node as a byte array.  Strings and string-like values will return
      * the UTF-8 encoding of the string.  Numerical values will return the byte representation of the
@@ -378,6 +457,18 @@ public byte[] asBytes() throws IllegalArgumentException {
         return value.asBytes();
     }
 
+    /**
+     * Get the value of this node as a byte array or {@code null} if this node is not {@link #isDefined() defined}.
+     * Strings and string-like values will return the UTF-8 encoding of the string.  Numerical values will return the
+     * byte representation of the number.
+     *
+     * @return the bytes or {@code null}
+     * @throws IllegalArgumentException if no conversion is possible
+     */
+    public byte[] asBytesOrNull() throws IllegalArgumentException {
+        return isDefined() ? value.asBytes() : null;
+    }
+
     /**
      * Get the value of this node as an expression.
      *

src/test/java/org/jboss/dmr/test/ModelNodeTest.java

@@ -47,6 +47,53 @@ public void testUndefinedAsString() {
         ModelNode testee = new ModelNode();
         assertEquals("undefined", testee.asString());
         assertEquals("a", testee.asString("a"));
+        assertNull(testee.asStringOrNull());
+    }
+
+    @Test
+    public void testUndefinedAsLong() {
+        ModelNode testee = testUndefinedConversion(ModelNode::asLong);
+        assertEquals(Long.MAX_VALUE, testee.asLong(Long.MAX_VALUE));
+        assertNull(testee.asLongOrNull());
+    }
+
+    @Test
+    public void testUndefinedAsInt() {
+        ModelNode testee = testUndefinedConversion(ModelNode::asInt);
+        assertEquals(Integer.MAX_VALUE, testee.asInt(Integer.MAX_VALUE));
+        assertNull(testee.asIntOrNull());
+    }
+
+    @Test
+    public void testUndefinedAsBoolean() {
+        ModelNode testee = testUndefinedConversion(ModelNode::asBoolean);
+        assertTrue(testee.asBoolean(true));
+        assertNull(testee.asBooleanOrNull());
+    }
+
+    @Test
+    public void testUndefinedAsDouble() {
+        ModelNode testee = testUndefinedConversion(ModelNode::asDouble);
+        assertEquals((double) 2, testee.asDouble((double) 2), 0);
+        assertNull(testee.asDoubleOrNull());
+    }
+
+    @Test
+    public void testUndefinedAsBigDecimal() {
+        ModelNode testee = testUndefinedConversion(ModelNode::asBigDecimal);
+        assertNull(testee.asBigDecimalOrNull());
+    }
+
+    @Test
+    public void testUndefinedAsBigInteger() {
+        ModelNode testee = testUndefinedConversion(ModelNode::asBigInteger);
+        assertNull(testee.asBigIntegerOrNull());
+    }
+
+    @Test
+    public void testUndefinedAsBytes() {
+        ModelNode testee = testUndefinedConversion(ModelNode::asBytes);
+        assertNull(testee.asBytesOrNull());
     }
 
     @Test