Simplified MIME multipart generation modes (legacy, strict and extended)

httpclient5/src/main/java/org/apache/hc/client5/http/entity/mime/HttpMultipartMode.java

@@ -28,18 +28,35 @@
 package org.apache.hc.client5.http.entity.mime;
 
 /**
+ * MIME compliance mode.
  *
  * @since 4.0
  */
 public enum HttpMultipartMode {
 
-    /** RFC 822, RFC 2045, RFC 2046 compliant */
+    /**
+     * Legacy compatibility mode.
+     * <p>
+     * In this mode only the most essential fields are generated
+     * such as Content-Type and Content-Disposition.
+     */
+    LEGACY,
+
+    /**
+     * Strict MIME specification conformance.
+     * <p>
+     * Presently conforms to RFC 822, RFC 2045, RFC 2046.
+     */
     STRICT,
-    /** browser-compatible mode, i.e. only write Content-Disposition; use content charset */
+
-    BROWSER_COMPATIBLE,
+    /**
-    /** RFC 6532 compliant */
+     * Extended MIME specification conformance.
-    RFC6532,
+     * <p>
-    /** RFC 7578 compliant */
+     * In this mode header field values may contain international UTF-8 encoded
-    RFC7578
+     * characters.
+     * <p>
+     * Presently conforms to RFC 6532 and RFC 7578.
+     */
+    EXTENDED,
 
 }

httpclient5/src/main/java/org/apache/hc/client5/http/entity/mime/LegacyMultipart.java

@@ -38,11 +38,11 @@ import java.util.List;
  *
  * @since 4.3
  */
-class HttpBrowserCompatibleMultipart extends AbstractMultipartFormat {
+class LegacyMultipart extends AbstractMultipartFormat {
 
     private final List<MultipartPart> parts;
 
-    public HttpBrowserCompatibleMultipart(
+    public LegacyMultipart(
             final Charset charset,
             final String boundary,
             final List<MultipartPart> parts) {

httpclient5/src/main/java/org/apache/hc/client5/http/entity/mime/MultipartEntityBuilder.java

@@ -56,9 +56,6 @@ public class MultipartEntityBuilder {
             "-_1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
                     .toCharArray();
 
-    private final static String FORM_SUBTYPE = "form-data";
-    private final static String MIXED_SUBTYPE = "mixed";
-
     private ContentType contentType;
     private HttpMultipartMode mode = HttpMultipartMode.STRICT;
     private String boundary = null;
@@ -78,7 +75,7 @@ public class MultipartEntityBuilder {
     }
 
     public MultipartEntityBuilder setLaxMode() {
-        this.mode = HttpMultipartMode.BROWSER_COMPATIBLE;
+        this.mode = HttpMultipartMode.LEGACY;
         return this;
     }
 
@@ -219,9 +216,9 @@ public class MultipartEntityBuilder {
             }
 
             if (formData) {
-                contentTypeCopy = ContentType.create("multipart/" + FORM_SUBTYPE, params);
+                contentTypeCopy = ContentType.MULTIPART_FORM_DATA.withParameters(params);
             } else {
-                contentTypeCopy = ContentType.create("multipart/" + MIXED_SUBTYPE, params);
+                contentTypeCopy = ContentType.create("multipart/mixed", params);
             }
         }
         final List<MultipartPart> multipartPartsCopy = multipartParts != null ? new ArrayList<>(multipartParts) :
@@ -229,17 +226,18 @@ public class MultipartEntityBuilder {
         final HttpMultipartMode modeCopy = mode != null ? mode : HttpMultipartMode.STRICT;
         final AbstractMultipartFormat form;
         switch (modeCopy) {
-            case BROWSER_COMPATIBLE:
+            case LEGACY:
-                form = new HttpBrowserCompatibleMultipart(charsetCopy, boundaryCopy, multipartPartsCopy);
+                form = new LegacyMultipart(charsetCopy, boundaryCopy, multipartPartsCopy);
                 break;
-            case RFC6532:
+            case EXTENDED:
-                form = new HttpRFC6532Multipart(charsetCopy, boundaryCopy, multipartPartsCopy);
+                if (ContentType.MULTIPART_FORM_DATA.isSameMimeType(ContentType.MULTIPART_FORM_DATA)) {
-                break;
+                    if (charsetCopy == null) {
-            case RFC7578:
+                        charsetCopy = StandardCharsets.UTF_8;
-                if (charsetCopy == null) {
+                    }
-                    charsetCopy = StandardCharsets.UTF_8;
+                    form = new HttpRFC7578Multipart(charsetCopy, boundaryCopy, multipartPartsCopy);
+                } else {
+                    form = new HttpRFC6532Multipart(charsetCopy, boundaryCopy, multipartPartsCopy);
                 }
-                form = new HttpRFC7578Multipart(charsetCopy, boundaryCopy, multipartPartsCopy);
                 break;
             default:
                 form = new HttpStrictMultipart(StandardCharsets.US_ASCII, boundaryCopy, multipartPartsCopy);

httpclient5/src/test/java/org/apache/hc/client5/http/entity/mime/TestMultipartEntityBuilder.java

@@ -58,7 +58,7 @@ public class TestMultipartEntityBuilder {
                 .setLaxMode()
                 .buildEntity();
         Assert.assertNotNull(entity);
-        Assert.assertTrue(entity.getMultipart() instanceof HttpBrowserCompatibleMultipart);
+        Assert.assertTrue(entity.getMultipart() instanceof LegacyMultipart);
         Assert.assertEquals("blah-blah", entity.getMultipart().boundary);
         Assert.assertEquals(StandardCharsets.UTF_8, entity.getMultipart().charset);
     }
@@ -151,7 +151,7 @@ public class TestMultipartEntityBuilder {
         parameters.add(new BasicNameValuePair(MimeConsts.FIELD_PARAM_FILENAME, "hello \u03BA\u03CC\u03C3\u03BC\u03B5!%"));
 
         final MultipartFormEntity entity = MultipartEntityBuilder.create()
-                .setMode(HttpMultipartMode.RFC7578)
+                .setMode(HttpMultipartMode.EXTENDED)
                 .setBoundary("xxxxxxxxxxxxxxxxxxxxxxxx")
                 .addPart(new FormBodyPartBuilder()
                         .setName("test")

httpclient5/src/test/java/org/apache/hc/client5/http/entity/mime/TestMultipartForm.java

@@ -300,7 +300,7 @@ public class TestMultipartForm {
         final FormBodyPart p2 = FormBodyPartBuilder.create(
                 "field2",
                 new InputStreamBody(new FileInputStream(tmpfile), s2 + ".tmp")).build();
-        final HttpBrowserCompatibleMultipart multipart = new HttpBrowserCompatibleMultipart(
+        final LegacyMultipart multipart = new LegacyMultipart(
                 StandardCharsets.UTF_8, "foo",
                 Arrays.<MultipartPart>asList(p1, p2));
 

httpclient5/src/test/java/org/apache/hc/client5/http/entity/mime/TestMultipartMixed.java

@@ -264,7 +264,7 @@ public class TestMultipartMixed {
         @SuppressWarnings("resource")
         final MultipartPart p2 = MultipartPartBuilder.create(
                 new InputStreamBody(new FileInputStream(tmpfile), s2 + ".tmp")).build();
-        final HttpBrowserCompatibleMultipart multipart = new HttpBrowserCompatibleMultipart(
+        final LegacyMultipart multipart = new LegacyMultipart(
                 StandardCharsets.UTF_8, "foo",
                 Arrays.<MultipartPart>asList(p1, p2));