UTF-8 encoding problem with MultiPart/RestEasy

Describe the bug I develop a rest API with MULTIPART_FORM. But I’m having problems with @Consumes charset. I sent some params to the controller which includes German characters. And it didn’t work as expected. The characters are not encoded properly, what can also be seen in debugging the properties in VSCode.

Some of the characters that cause the problem:

• ä, Ä, ü, Ü, ö, Ö, ß

Instead, I receive:

• ��

Expected behavior

• Receive all Umlaut, etc. UTF-8

To Reproduce Using httpie:

http -f POST localhost:8080/general content="Test-Ä" file@testFile.png

Response:

HTTP/1.1 200 OK
Content-Length: 11
Content-Type: text/plain;charset=UTF-8

Test-��

Ressource:

import org.jboss.resteasy.annotations.providers.multipart.MultipartForm;
import javax.ws.rs.Consumes;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

public class FeedbackResource {

    @POST
    @Path("/general")
    @Produces(MediaType.TEXT_PLAIN)
    @Consumes(MediaType.MULTIPART_FORM_DATA+";charset=UTF-8")
    public String postForm(@MultipartForm final FeedbackBody feedback) {
        return feedback.content;
    }
}

Model:

package org.acme;

import org.jboss.resteasy.annotations.providers.multipart.PartType;

import javax.ws.rs.FormParam;
import javax.ws.rs.core.MediaType;

public class FeedbackBody {

    private byte[] file;
    public byte[] getFile() {
        return file;
    }

    @FormParam("file")
    @PartType(MediaType.APPLICATION_OCTET_STREAM)
    public void setFile(byte[] file) {
        this.file = file;
    }

    @FormParam("fileName")
    @PartType(MediaType.TEXT_PLAIN)
    public String fileName;

    @FormParam("content")
    @PartType(MediaType.TEXT_PLAIN+";charset=UTF-8")
    public String content;
}

Configuration

# Add your application.properties here, if applicable.
<properties>
    <compiler-plugin.version>3.8.1</compiler-plugin.version>
    <maven.compiler.parameters>true</maven.compiler.parameters>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <quarkus-plugin.version>1.5.1.Final</quarkus-plugin.version>
    <quarkus.platform.artifact-id>quarkus-universe-bom</quarkus.platform.artifact-id>
    <quarkus.platform.group-id>io.quarkus</quarkus.platform.group-id>
    <quarkus.platform.version>1.5.1.Final</quarkus.platform.version>
    <surefire-plugin.version>2.22.1</surefire-plugin.version>
  </properties>

Environment (please complete the following information):

• Output of uname -a or ver: Darwin Mac.local 19.5.0 Darwin Kernel Version 19.5.0: Tue May 26 20:41:44 PDT 2020; root:xnu-6153.121.2~2/RELEASE_X86_64 x86_64
• Output of java -version: openjdk version “11.0.6” 2020-01-14 OpenJDK Runtime Environment GraalVM CE 19.3.1 (build 11.0.6+9-jvmci-19.3-b07) OpenJDK 64-Bit Server VM GraalVM CE 19.3.1 (build 11.0.6+9-jvmci-19.3-b07, mixed mode, sharing)
• Quarkus version or git rev: 1.5.1.Final
• Build tool (ie. output of mvnw --version or gradlew --version): Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f) Maven home: /Users/.m2/wrapper/dists/apache-maven-3.6.3-bin/1iopthnavndlasol9gbrbg6bf2/apache-maven-3.6.3 Java version: 11.0.6, vendor: Oracle Corporation, runtime: /Users/christian/.sdkman/candidates/java/19.3.1.r11-grl Default locale: en_GB, platform encoding: UTF-8 OS name: “mac os x”, version: “10.15.5”, arch: “x86_64”, family: “mac”