fix up remaining errors

src/extension/importer/rest-ng/src/main/java/org/geoserver/importer/rest/ImportTaskController.java

@@ -75,7 +75,7 @@ public ImportTask taskGet(@PathVariable Long id, @PathVariable Integer taskId) {
 
     @GetMapping(path = {"/{taskId}/progress"}, produces = { MediaType.APPLICATION_JSON_VALUE,
             CatalogController.TEXT_JSON , MediaType.TEXT_HTML_VALUE})
-    public ImportJSONWrapper progressGet(@PathVariable Long id, @PathVariable Integer taskId) {
+    public ImportWrapper progressGet(@PathVariable Long id, @PathVariable Integer taskId) {
 
         JSONObject progress = new JSONObject();
         ImportTask inProgress = importer.getCurrentlyProcessingTask(id);
@@ -96,7 +96,7 @@ public ImportJSONWrapper progressGet(@PathVariable Long id, @PathVariable Intege
         } catch (JSONException jex) {
             throw new RestException("Internal Error", HttpStatus.INTERNAL_SERVER_ERROR, jex);
         }
-        return new ImportJSONWrapper(progress);
+        return (writer,builder,converter) -> writer.write(progress.toString());
     }
 
     @GetMapping(path = {"/{taskId}/target"}, produces = { MediaType.APPLICATION_JSON_VALUE,

src/extension/importer/rest-ng/src/main/java/org/geoserver/importer/rest/converters/ImportTransformJSONMessageConverter.java

@@ -0,0 +1,74 @@
+/* (c) 2017 Open Source Geospatial Foundation - all rights reserved
+ * This code is licensed under the GPL 2.0 license, available at the root
+ * application directory.
+ */
+package org.geoserver.importer.rest.converters;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStreamWriter;
+
+import org.geoserver.importer.ImportContext;
+import org.geoserver.importer.ImportTask;
+import org.geoserver.importer.Importer;
+import org.geoserver.importer.rest.converters.ImportJSONWriter.FlushableJSONBuilder;
+import org.geoserver.importer.transform.ImportTransform;
+import org.geoserver.rest.catalog.CatalogController;
+import org.geoserver.rest.converters.BaseMessageConverter;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpInputMessage;
+import org.springframework.http.HttpOutputMessage;
+import org.springframework.http.MediaType;
+import org.springframework.http.converter.HttpMessageNotReadableException;
+import org.springframework.http.converter.HttpMessageNotWritableException;
+import org.springframework.stereotype.Component;
+
+import net.sf.json.JSONObject;
+
+/**
+ * Convert {@link ImportTask} to/from JSON.
+ */
+@Component
+public class ImportTransformJSONMessageConverter extends BaseMessageConverter<ImportTransform> {
+
+    Importer importer;
+
+    @Autowired
+    public ImportTransformJSONMessageConverter(Importer importer) {
+        super(MediaType.APPLICATION_JSON, CatalogController.MEDIATYPE_TEXT_JSON);
+        this.importer = importer;
+    }
+
+    @Override
+    public int getPriority() {
+        return super.getPriority() - 5;
+    }
+
+    @Override
+    protected boolean supports(Class<?> clazz) {
+        return ImportTransform.class.isAssignableFrom(clazz);
+    }
+
+    //
+    // Reading
+    //
+    @Override
+    protected ImportTransform readInternal(Class<? extends ImportTransform> clazz,
+            HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException {
+        try (InputStream in = inputMessage.getBody()) {
+            ImportJSONReader reader = new ImportJSONReader(importer);
+            JSONObject json = reader.parse(in);
+            ImportTransform transform = reader.transform(json);
+
+            return transform;
+        }
+    }
+
+    //
+    // writing
+    //
+    @Override
+    protected boolean canWrite(MediaType mediaType) {
+        return false;
+    }
+}

src/extension/importer/rest-ng/src/main/java/org/geoserver/importer/rest/converters/TransformChainJSONMessageConverter.java

@@ -0,0 +1,69 @@
+/* (c) 2017 Open Source Geospatial Foundation - all rights reserved
+ * This code is licensed under the GPL 2.0 license, available at the root
+ * application directory.
+ */
+package org.geoserver.importer.rest.converters;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.geoserver.importer.ImportTask;
+import org.geoserver.importer.Importer;
+import org.geoserver.importer.transform.TransformChain;
+import org.geoserver.rest.catalog.CatalogController;
+import org.geoserver.rest.converters.BaseMessageConverter;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpInputMessage;
+import org.springframework.http.MediaType;
+import org.springframework.http.converter.HttpMessageNotReadableException;
+import org.springframework.stereotype.Component;
+
+import net.sf.json.JSONObject;
+
+/**
+ * Convert {@link ImportTask} to/from JSON.
+ */
+@Component
+public class TransformChainJSONMessageConverter extends BaseMessageConverter<TransformChain<?>> {
+
+    Importer importer;
+
+    @Autowired
+    public TransformChainJSONMessageConverter(Importer importer) {
+        super(MediaType.APPLICATION_JSON, CatalogController.MEDIATYPE_TEXT_JSON);
+        this.importer = importer;
+    }
+
+    @Override
+    public int getPriority() {
+        return super.getPriority() - 5;
+    }
+
+    @Override
+    protected boolean supports(Class<?> clazz) {
+        return TransformChain.class.isAssignableFrom(clazz);
+    }
+
+    //
+    // Reading
+    //
+    @Override
+    protected TransformChain<?> readInternal(Class<? extends TransformChain<?>> clazz,
+            HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException {
+        try (InputStream in = inputMessage.getBody()) {
+            ImportJSONReader reader = new ImportJSONReader(importer);
+            JSONObject json = reader.parse(in);
+            TransformChain<?> transform = (TransformChain<?>) reader.transform(json);
+
+            return transform;
+        }
+    }
+
+    //
+    // writing
+    //
+    @Override
+    protected boolean canWrite(MediaType mediaType) {
+        return false;
+    }
+}

src/extension/importer/rest-ng/src/test/java/org/geoserver/importer/rest/ImportTaskControllerTest.java

@@ -192,7 +192,7 @@ public void testGetTask() throws Exception {
 
     @Test
     public void testGetTaskProgress() throws Exception {
-        JSONObject json = (JSONObject) getAsJSON(RestBaseController.ROOT_PATH+"/imports/0/tasks/0/progress");
+        JSONObject json = (JSONObject) getAsJSON(RestBaseController.ROOT_PATH+"/imports/0/tasks/0/progress",200);
         assertEquals("READY", json.get("state"));
         //TODO: trigger import and check progress
     }

src/main/src/test/java/org/geoserver/test/GeoServerSystemTestSupport.java

@@ -1277,6 +1277,16 @@ protected Document getAsDOM(final String path, String encoding) throws Exception
     protected JSON getAsJSON(final String path, int statusCode)
             throws Exception {
         MockHttpServletResponse response = getAsServletResponse(path, statusCode);
+        int status = response.getStatus();
+        if( statusCode != status ){
+            String content = response.getContentAsString();
+            if( content == null || content.length() == 0 ){
+                throw new ServiceException("expected status <"+statusCode+"> but was <"+status+">");
+            }
+            else {
+                throw new ServiceException("expected status <"+statusCode+"> but was <"+status+">:"+content);
+            }
+        }
         return json(response);
     }