Not sure how to set up for flutter

[bradyt]

Describe the bug

When writing a Flutter app, we may have to edit the Java source, like MainActivity.java, for example, to write a Platform Channel. Being new to Android and Java, it is not obvious how to properly configure things, especially to get lsp-java working in the Java files.

When I tried on my system, I got

LSP :: MainActivity.java isn't on the classpath. Only syntax errors will be reported

I selected android/ as the project root. Some files and directories, such as .project, were added to android/ and android/app/.

I tried to create a Dockerfile for a recipe to reproduce, but I got instead some errors about gradle, perhaps revealing how little I understand about the Android toolchain.

Here is my Dockerfile:

FROM silex/emacs

RUN apt-get update && apt-get install -y \
        openjdk-8-jdk-headless \
        && rm -rf /var/lib/apt/lists/*

ADD .emacs.d /root/.emacs.d
RUN emacs -batch -l ~/.emacs.d/install.el -f lsp-java-update-server

WORKDIR /root/

RUN curl -L https://github.com/flutter/flutter/archive/v1.7.8+hotfix.2.tar.gz \
        --output flutter-1.7.8-hotfix.2.tar.gz \
        && tar xvzf flutter-1.7.8-hotfix.2.tar.gz \
        && rm flutter-1.7.8-hotfix.2.tar.gz

WORKDIR /root/flutter-1.7.8-hotfix.2/examples/hello_world/android/app/src/main/java/io/flutter/examples/hello_world/

CMD "emacs" "MainActivity.java"

Here is an install.el file.

(setq package-archives
      '(("gnu" . "https://elpa.gnu.org/packages/")
        ("melpa" . "https://melpa.org/packages/")))
(package-initialize)

(package-refresh-contents)

(mapc 'package-install '(spinner lsp-java))

And here is an init.el file.

(setq package-archives
      '(("gnu" . "https://elpa.gnu.org/packages/")
        ("melpa" . "https://melpa.org/packages/")))
(package-initialize)

(unless package-archive-contents
  (package-refresh-contents))

(add-hook 'java-mode-hook (defun my-set-java-tab-width () (setq tab-width 2)))
(setq lsp-java-format-settings-url "https://raw.githubusercontent.com/google/styleguide/gh-pages/eclipse-java-google-style.xml")
(setq lsp-java-format-settings-profile "GoogleStyle")
(setq lsp-enable-snippet nil)

(require 'lsp-java)
(add-hook 'java-mode-hook 'lsp)

(require 'cc-mode)

(setcdr (assoc 'java-mode c-default-style) "java-google-style-indentation")

(c-add-style "java-google-style-indentation"
             '((c-basic-offset . 2)
               (c-offsets-alist
                (inexpr-class . 0)
                (case-label . +)
                (statement-cont . ++))))

That was my attempt at describing my environment, but I'm afraid I don't know yet how to get it working as well in Docker.

I got errors like,

Jul 4, 2019 5:05:40 AM Synchronize project android failed due to an error in the referenced Gradle build.                                                    
Could not run phased build action using Gradle distribution 'https://services.gradle.org/distributions/gradle-5.4-bin.zip'.                                  
org.gradle.tooling.BuildException: Could not run phased build action using Gradle distribution 'https://services.gradle.org/distributions/gradle-5.4-bin.zip'.

[bradyt]

Possible related: #132, similar classpath issue, but not flutter related.

[yyoncho]

AFAIK the language server does not support Android projects - refer to their readme - https://github.com/eclipse/eclipse.jdt.ls and eclipse-jdtls/eclipse.jdt.ls#923

[bradyt]

Ah okay, thank you for clarification.