Fixed spring form encoder for multiple MultipartFile

feign-form-spring/src/main/java/feign/form/spring/SpringFormEncoder.java

@@ -20,7 +20,9 @@
 import static java.util.Collections.singletonMap;
 
 import java.lang.reflect.Type;
-import java.util.HashMap;
+import java.util.Arrays;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
 
 import feign.RequestTemplate;
 import feign.codec.EncodeException;
@@ -63,22 +65,15 @@ public SpringFormEncoder (Encoder delegate) {
   public void encode (Object object, Type bodyType, RequestTemplate template) throws EncodeException {
     if (bodyType.equals(MultipartFile[].class)) {
       val files = (MultipartFile[]) object;
-      val data = new HashMap<String, Object>(files.length, 1.F);
-      for (val file : files) {
-        data.put(file.getName(), file);
-      }
+      val data = Arrays.stream(files).collect(Collectors.groupingBy(MultipartFile::getName));
       super.encode(data, MAP_STRING_WILDCARD, template);
     } else if (bodyType.equals(MultipartFile.class)) {
       val file = (MultipartFile) object;
       val data = singletonMap(file.getName(), object);
       super.encode(data, MAP_STRING_WILDCARD, template);
     } else if (isMultipartFileCollection(object)) {
-      val iterable = (Iterable<?>) object;
-      val data = new HashMap<String, Object>();
-      for (val item : iterable) {
-        val file = (MultipartFile) item;
-        data.put(file.getName(), file);
-      }
+      val iterable = (Iterable<MultipartFile>) object;
+      val data =  StreamSupport.stream(iterable.spliterator(), false).collect(Collectors.groupingBy(MultipartFile::getName));
       super.encode(data, MAP_STRING_WILDCARD, template);
     } else {
       super.encode(object, bodyType, template);

feign-form-spring/src/test/java/feign/form/feign/spring/Client.java

@@ -108,6 +108,20 @@ String upload4 (@PathVariable("id") String id,
   )
   String upload6Collection (@RequestPart List<MultipartFile> files);
 
+  @RequestMapping(
+          path = "/multipart/upload7",
+          method = POST,
+          consumes = MULTIPART_FORM_DATA_VALUE
+  )
+  String upload7Array (@RequestPart MultipartFile[] files);
+
+  @RequestMapping(
+          path = "/multipart/upload7",
+          method = POST,
+          consumes = MULTIPART_FORM_DATA_VALUE
+  )
+  String upload7Collection (@RequestPart List<MultipartFile> files);
+
   class ClientConfiguration {
 
     @Autowired

feign-form-spring/src/test/java/feign/form/feign/spring/Server.java

@@ -25,6 +25,7 @@
 import static org.springframework.web.bind.annotation.RequestMethod.POST;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Map;
 
 import lombok.SneakyThrows;
@@ -133,6 +134,19 @@ public ResponseEntity<String> upload6 (@RequestParam("popa1") MultipartFile popa
     return ResponseEntity.status(status).body(result);
   }
 
+  @RequestMapping(
+          path = "/multipart/upload7",
+          method = POST,
+          consumes = MULTIPART_FORM_DATA_VALUE
+  )
+  public ResponseEntity<String> upload7 (@RequestParam("files") MultipartFile[] files) throws Exception {
+    StringBuilder result = new StringBuilder();
+    for (MultipartFile kek: files) {
+      result.append(new String(kek.getBytes()));
+    }
+    return ResponseEntity.ok(result.toString());
+  }
+
   @RequestMapping(
       path = "/multipart/download/{fileId}",
       method = GET,

feign-form-spring/src/test/java/feign/form/feign/spring/SpringFormEncoderTest.java

@@ -133,4 +133,24 @@ public void upload6CollectionTest () throws Exception {
     val response = client.upload6Collection(list);
     Assert.assertEquals("Hello world", response);
   }
+
+  @Test
+  public void upload7ArrayTest () throws Exception {
+    val file1 = new MockMultipartFile("files", "debug", null, "Hello".getBytes(UTF_8));
+    val file2 = new MockMultipartFile("files", "release", null, " world".getBytes(UTF_8));
+
+    val response = client.upload7Array(new MultipartFile[] { file1, file2 });
+    Assert.assertEquals("Hello world", response);
+  }
+
+  @Test
+  public void upload7CollectionTest () throws Exception {
+    List<MultipartFile> list = asList(
+            new MockMultipartFile("files", "debug", null, "Hello".getBytes(UTF_8)),
+            new MockMultipartFile("files", "release", null, " world".getBytes(UTF_8))
+    );
+
+    val response = client.upload7Collection(list);
+    Assert.assertEquals("Hello world", response);
+  }
 }