Merge pull request #1237 from bimargulies/java-nio-path

Issue #1235; rework to complete the implementation for Path.

Author: cowtowncoder

pom.xml

@@ -81,6 +81,12 @@
       <version>1.0.0</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.jimfs</groupId>
+      <artifactId>jimfs</artifactId>
+      <version>1.1</version>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>

src/main/java/com/fasterxml/jackson/databind/ext/Java7PathDeserializer.java

@@ -9,6 +9,10 @@
 import com.fasterxml.jackson.databind.DeserializationContext;
 import com.fasterxml.jackson.databind.deser.std.StdScalarDeserializer;
 
+/**
+ * Obsolete deserializer for Java.nio.file.Path that only handles the default file system.
+ */
+@Deprecated
 public class Java7PathDeserializer extends StdScalarDeserializer<Path>
 {
     private static final long serialVersionUID = 1;

src/main/java/com/fasterxml/jackson/databind/ext/Java7Support.java

@@ -1,6 +1,7 @@
 package com.fasterxml.jackson.databind.ext;
 
 import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonSerializer;
 import com.fasterxml.jackson.databind.PropertyName;
 import com.fasterxml.jackson.databind.introspect.Annotated;
 import com.fasterxml.jackson.databind.introspect.AnnotatedParameter;
@@ -42,4 +43,6 @@ public static Java7Support instance() {
     public abstract Class<?> getClassJavaNioFilePath();
 
     public abstract JsonDeserializer<?> getDeserializerForJavaNioFilePath(Class<?> rawType);
+
+    public abstract JsonSerializer<?> getSerializerForJavaNioFilePath(Class<?> rawType);
 }

src/main/java/com/fasterxml/jackson/databind/ext/Java7SupportImpl.java

@@ -5,6 +5,7 @@
 import java.nio.file.Path;
 
 import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonSerializer;
 import com.fasterxml.jackson.databind.PropertyName;
 import com.fasterxml.jackson.databind.introspect.Annotated;
 import com.fasterxml.jackson.databind.introspect.AnnotatedParameter;
@@ -33,11 +34,19 @@ public Class<?> getClassJavaNioFilePath() {
     @Override
     public JsonDeserializer<?> getDeserializerForJavaNioFilePath(Class<?> rawType) {
         if (rawType == Path.class) {
-            return new Java7PathDeserializer();
+            return new NioPathDeserializer();
         }
         return null;
     }
-    
+
+    @Override
+    public JsonSerializer<?> getSerializerForJavaNioFilePath(Class<?> rawType) {
+        if (Path.class.isAssignableFrom(rawType)) {
+            return new NioPathSerializer();
+        }
+        return null;
+    }
+
     @Override
     public Boolean findTransient(Annotated a) {
         Transient t = a.getAnnotation(Transient.class);

src/main/java/com/fasterxml/jackson/databind/ext/NioPathDeserializer.java

@@ -0,0 +1,33 @@
+package com.fasterxml.jackson.databind.ext;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+/**
+ *
+ */
+public class NioPathDeserializer extends JsonDeserializer<Path> {
+    @Override
+    public Path deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
+        if (p.getCurrentToken() == JsonToken.VALUE_NULL) {
+            return null;
+        } else if (p.getCurrentToken() != JsonToken.VALUE_STRING) {
+            throw ctxt.wrongTokenException(p, JsonToken.VALUE_STRING, "The value of a java.nio.file.Path must be a string");
+        }
+        URI uri;
+        try {
+            uri = new URI(p.readValueAs(String.class));
+        } catch (URISyntaxException e) {
+            throw ctxt.instantiationException(Path.class, e);
+        }
+        return Paths.get(uri);
+    }
+}

src/main/java/com/fasterxml/jackson/databind/ext/NioPathSerializer.java

@@ -0,0 +1,24 @@
+
+package com.fasterxml.jackson.databind.ext;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+/**
+ *
+ */
+public class NioPathSerializer extends JsonSerializer<Path> {
+    @Override
+    public void serialize(Path value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
+        if (value == null) {
+            gen.writeNull();
+        } else {
+            // write the Path as a URI, always.
+            gen.writeString(value.toUri().toString());
+        }
+    }
+}

src/main/java/com/fasterxml/jackson/databind/ext/OptionalHandlerFactory.java

@@ -85,9 +85,9 @@ public JsonSerializer<?> findSerializer(SerializationConfig config, JavaType typ
         final Class<?> rawType = type.getRawClass();
 
         if (_jdk7Helper != null) {
-            Class<?> path = _jdk7Helper.getClassJavaNioFilePath();
-            if (path.isAssignableFrom(rawType)) {
-                return ToStringSerializer.instance;
+            JsonSerializer<?> ser = _jdk7Helper.getSerializerForJavaNioFilePath(rawType);
+            if (ser != null) {
+                return ser;
             }
         }
         if ((CLASS_DOM_NODE != null) && CLASS_DOM_NODE.isAssignableFrom(rawType)) {

src/test/java/com/fasterxml/jackson/databind/ext/TestJdk7Types.java

@@ -1,9 +1,12 @@
 package com.fasterxml.jackson.databind.ext;
 
+import java.nio.file.FileSystem;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 
 import com.fasterxml.jackson.databind.*;
+import com.google.common.jimfs.Configuration;
+import com.google.common.jimfs.Jimfs;
 
 /**
  * @since 2.7
@@ -13,9 +16,9 @@ public class TestJdk7Types extends BaseMapTest
     public void testPathRoundtrip() throws Exception
     {
         ObjectMapper mapper = new ObjectMapper();
-    
-        // Start with serialization, actually
-        Path input = Paths.get("tmp", "foo.txt");
+
+        FileSystem fs = Jimfs.newFileSystem(Configuration.unix());
+        Path input = fs.getPath("/tmp", "foo.txt");
 
         String json = mapper.writeValueAsString(input);
         assertNotNull(json);
@@ -24,5 +27,6 @@ public void testPathRoundtrip() throws Exception
         assertNotNull(p);
 
         assertEquals(input.toUri(), p.toUri());
+        assertEquals(input, p);
     }
 }