Fixed #413

FasterXML · Jun 23, 2020 · cbabade · cbabade
1 parent d895334
commit cbabade
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diff --git a/release-notes/CREDITS-2.x b/release-notes/CREDITS-2.x
@@ -65,3 +65,8 @@ Martin Vysny (mvysny@github)
 
 * Reported #395: Namespace repairing generates xmlns definitions for xml: prefix (which is implicit)
  (2.10.5)
+
+James Bushell (jimnz111@github)
+
+* Suggested #413: Null String field serialization through ToXmlGenerator causes NullPointerException
+ (2.10.5)
diff --git a/release-notes/VERSION-2.x b/release-notes/VERSION-2.x
@@ -8,7 +8,9 @@ Project: jackson-dataformat-xml
 
 #395: Namespace repairing generates xmlns definitions for xml: prefix (which is implicit)
  (reported by Martin V)
-- Upgrade Woodstox dependency to 6.2.0 (minor fix to namespace binding)
+#413: Null String field serialization through ToXmlGenerator causes NullPointerException
+ (suggested by James B)
+- Upgrade Woodstox dependency to 6.2.1
 
 2.10.4 (03-May-2020)
 

diff --git a/src/main/java/com/fasterxml/jackson/dataformat/xml/ser/ToXmlGenerator.java b/src/main/java/com/fasterxml/jackson/dataformat/xml/ser/ToXmlGenerator.java
@@ -590,10 +590,14 @@ public void writeFieldName(SerializableString name) throws IOException
     {
         writeFieldName(name.getValue());
     }
-    
+
     @Override
     public void writeString(String text) throws IOException
     {
+        if (text == null) { // [dataformat-xml#413]
+            writeNull();
+            return;
+        }
         _verifyValueWrite("write String value");
         if (_nextName == null) {
             handleMissingName();

diff --git a/src/test/java/com/fasterxml/jackson/dataformat/xml/stream/XmlGeneratorTest.java b/src/test/java/com/fasterxml/jackson/dataformat/xml/stream/XmlGeneratorTest.java
@@ -12,11 +12,12 @@
 
 public class XmlGeneratorTest extends XmlTestBase
 {
+    private final XmlFactory XML_F = new XmlFactory();
+
     public void testSimpleElement() throws Exception
     {
-        XmlFactory f = new XmlFactory();
         StringWriter out = new StringWriter();
-        ToXmlGenerator gen = f.createGenerator(out);
+        ToXmlGenerator gen = XML_F.createGenerator(out);
         // root name is special, need to be fed first:
         gen.setNextName(new QName("root"));
         gen.writeStartObject();
@@ -30,11 +31,37 @@ public void testSimpleElement() throws Exception
         assertEquals("<root><elem>value</elem></root>", xml);
     }
 
+    public void testNullValuedElement() throws Exception
+    {
+        // First explicitly written
+        StringWriter out = new StringWriter();
+        ToXmlGenerator gen = XML_F.createGenerator(out);
+        gen.setNextName(new QName("root"));
+        gen.writeStartObject();
+        gen.writeFieldName("elem");
+        gen.writeNull();
+        gen.writeEndObject();
+        gen.close();
+        String xml = removeSjsxpNamespace(out.toString());
+        assertEquals("<root><elem/></root>", xml);
+
+        // and then indirectly (see [dataformat-xml#413])
+        out = new StringWriter();
+        gen = XML_F.createGenerator(out);
+        gen.setNextName(new QName("root"));
+        gen.writeStartObject();
+        gen.writeFieldName("elem");
+        gen.writeString((String) null);
+        gen.writeEndObject();
+        gen.close();
+        xml = removeSjsxpNamespace(out.toString());
+        assertEquals("<root><elem/></root>", xml);
+    }
+
     public void testSimpleAttribute() throws Exception
     {
-        XmlFactory f = new XmlFactory();
         StringWriter out = new StringWriter();
-        ToXmlGenerator gen = f.createGenerator(out);
+        ToXmlGenerator gen = XML_F.createGenerator(out);
         // root name is special, need to be fed first:
         gen.setNextName(new QName("root"));
         gen.writeStartObject();
@@ -52,9 +79,8 @@ public void testSimpleAttribute() throws Exception
 
     public void testSecondLevelAttribute() throws Exception
     {
-        XmlFactory f = new XmlFactory();
         StringWriter out = new StringWriter();
-        ToXmlGenerator gen = f.createGenerator(out);
+        ToXmlGenerator gen = XML_F.createGenerator(out);
         gen.setNextName(new QName("root"));
         gen.writeStartObject();
         gen.writeFieldName("elem");
@@ -74,9 +100,8 @@ public void testSecondLevelAttribute() throws Exception
 
     public void testAttrAndElem() throws Exception
     {
-        XmlFactory f = new XmlFactory();
         StringWriter out = new StringWriter();
-        ToXmlGenerator gen = f.createGenerator(out);
+        ToXmlGenerator gen = XML_F.createGenerator(out);
         gen.setNextName(new QName("root"));
         gen.writeStartObject();
         // and also need to force attribute
@@ -109,9 +134,8 @@ public void testWriteToFile() throws Exception
 
     public void testRawSimpleValue() throws Exception
     {
-        XmlFactory f = new XmlFactory();
         StringWriter out = new StringWriter();
-        ToXmlGenerator gen = f.createGenerator(out);
+        ToXmlGenerator gen = XML_F.createGenerator(out);
         // root name is special, need to be fed first:
         gen.setNextName(new QName("root"));
         gen.writeStartObject();
@@ -127,9 +151,8 @@ public void testRawSimpleValue() throws Exception
 
     public void testRawOffsetValue() throws Exception
     {
-        XmlFactory f = new XmlFactory();
         StringWriter out = new StringWriter();
-        ToXmlGenerator gen = f.createGenerator(out);
+        ToXmlGenerator gen = XML_F.createGenerator(out);
         // root name is special, need to be fed first:
         gen.setNextName(new QName("root"));
         gen.writeStartObject();
@@ -145,9 +168,8 @@ public void testRawOffsetValue() throws Exception
 
     public void testRawCharArrayValue() throws Exception
     {
-        XmlFactory f = new XmlFactory();
         StringWriter out = new StringWriter();
-        ToXmlGenerator gen = f.createGenerator(out);
+        ToXmlGenerator gen = XML_F.createGenerator(out);
         // root name is special, need to be fed first:
         gen.setNextName(new QName("root"));
         gen.writeStartObject();
@@ -163,9 +185,8 @@ public void testRawCharArrayValue() throws Exception
 
     public void testRawSimpleAttribute() throws Exception
     {
-        XmlFactory f = new XmlFactory();
         StringWriter out = new StringWriter();
-        ToXmlGenerator gen = f.createGenerator(out);
+        ToXmlGenerator gen = XML_F.createGenerator(out);
         // root name is special, need to be fed first:
         gen.setNextName(new QName("root"));
         gen.writeStartObject();
@@ -183,9 +204,8 @@ public void testRawSimpleAttribute() throws Exception
 
     public void testRawOffsetAttribute() throws Exception
     {
-        XmlFactory f = new XmlFactory();
         StringWriter out = new StringWriter();
-        ToXmlGenerator gen = f.createGenerator(out);
+        ToXmlGenerator gen = XML_F.createGenerator(out);
         // root name is special, need to be fed first:
         gen.setNextName(new QName("root"));
         gen.writeStartObject();
@@ -203,9 +223,8 @@ public void testRawOffsetAttribute() throws Exception
 
     public void testRawCharArratAttribute() throws Exception
     {
-        XmlFactory f = new XmlFactory();
         StringWriter out = new StringWriter();
-        ToXmlGenerator gen = f.createGenerator(out);
+        ToXmlGenerator gen = XML_F.createGenerator(out);
         // root name is special, need to be fed first:
         gen.setNextName(new QName("root"));
         gen.writeStartObject();