问题
I'm trying to run AwesomeProject on my Nexus5 (android 5.1.1).
I'm able to build the project and install it on the device. But when I run it, I got a red screen saying
Unable to download JS bundle. Did you forget to start the development server or connect your device?
In react native iOS, I can choose to load jsbundle offline. How can I do the same thing for Android? (Or at least, where can I configure the server address?)
Update
To run with local server, run the following commands under your react-native project root directory
react-native start > /dev/null 2>&1 &
adb reverse tcp:8081 tcp:8081
please take a look at dsissitka's answer for more details.
To run without a server, bundle the jsfile into the apk by running:
- create an assets folder under
android/app/src/main
curl "http://localhost:8081/index.android.bundle?platform=android" -o "android/app/src/main/assets/index.android.bundle"
please take a look at kzzzf's answer for more details.
回答1:
To bundle JS file into your apk while having your server running (react-native start
) download bundle into assets directory of your app:
curl "http://localhost:8081/index.android.bundle?platform=android" -o "android/app/src/main/assets/index.android.bundle"
With the next release (0.12) we'll fix react-native bundle
command to work with android projects as expected.
回答2:
The following made it work for me on Ubuntu 14.04:
cd (App Dir)
react-native start > /dev/null 2>&1 &
adb reverse tcp:8081 tcp:8081
Update: See
- Running On Device (Android)
- Device warning suppressed?
Update 2: @scgough We got this error because React Native (RN) was unable to fetch JavaScript from the dev server running on our workstations. You can see why this happens here:
https://github.com/facebook/react-native/blob/42eb5464fd8a65ed84b799de5d4dc225349449be/ReactAndroid/src/main/java/com/facebook/react/devsupport/DevServerHelper.java#L116-L137
If your RN app detects that you're using Genymotion or the emulator it tries to fetch the JavaScript from GENYMOTION_LOCALHOST (10.0.3.2) or EMULATOR_LOCALHOST (10.0.2.2). Otherwise it presumes that you're using a device and it tries to fetch the JavaScript from DEVICE_LOCALHOST (localhost). The problem is that the dev server runs on your workstation's localhost, not the device's, so in order to get it to work you need to either:
- Forward traffic from (Device's localhost):8081/tcp to (Workstation's localhost):8081/tcp. That's what that adb command does.
- Tell your RN app where it can find your dev server.
回答3:
Ok, I think I've figured what the issue is here. It was to do with the version of watchman
I was running.
In a new shell, run brew update
then: brew unlink watchman
then: brew install watchman
now, you can run react-native start
from your project folder
I leave this shell open, create a new shell window and run: react-native run-android
from my project folder. All is right with the world.
ps. I was originally on version 3.2 of watchman. This upgraded me to 3.7.
pps. I'm new to this so that might not be the swiftest route to the solution but it has worked for me.
* MORE INFO FOR RUNNING/DEBUGGING ON A DEVICE *
You might find that if you deploy your app to your Android device rather than an emulater you get a red screen of death with an error saying Unable to load JS Bundle
. You need to set the debug server for your device to be your computer running react...either its name OR IP address.
- Press the device
Menu
button - Select
Dev Settings
- Select
Debug server host for device
- Type in your machine's IP and Reload JS plus the react port e.g.
192.168.1.10:8081
More info: http://facebook.github.io/react-native/docs/running-on-device-android.html
回答4:
From your project directory, run
react-native start
It outputs the following:
$ react-native start
┌────────────────────────────────────────────────────────────────────────────┐
│ Running packager on port 8081. │
│ │
│ Keep this packager running while developing on any JS projects. Feel │
│ free to close this tab and run your own packager instance if you │
│ prefer. │
│ │
│ https://github.com/facebook/react-native │
│ │
└────────────────────────────────────────────────────────────────────────────┘
Looking for JS files in
/home/user/AwesomeProject
React packager ready.
[11:30:10 PM] <START> Building Dependency Graph
[11:30:10 PM] <START> Crawling File System
[11:30:16 PM] <END> Crawling File System (5869ms)
[11:30:16 PM] <START> Building in-memory fs for JavaScript
[11:30:17 PM] <END> Building in-memory fs for JavaScript (852ms)
[11:30:17 PM] <START> Building in-memory fs for Assets
[11:30:17 PM] <END> Building in-memory fs for Assets (838ms)
[11:30:17 PM] <START> Building Haste Map
[11:30:18 PM] <START> Building (deprecated) Asset Map
[11:30:18 PM] <END> Building (deprecated) Asset Map (220ms)
[11:30:18 PM] <END> Building Haste Map (759ms)
[11:30:18 PM] <END> Building Dependency Graph (8319ms)
回答5:
An easy solution that works for me with Ubuntu 14.04.
react-native run-android
The emulator (already launched) will return: Unable to download JS Bundle; start again the JS server:
react-native start
Hit Reload JS on the emulator. It worked for me. Hope it will help
回答6:
In the app on android I opened Menu (Command + M in Genymotion) -> Dev Settings -> Debug server host & port for device
set the value to: localhost:8081
It worked for me.
回答7:
After trying out a combination of the answers here, this is what is working for me.
I'm using Genymotion as my emulator.
1 Start up Genymotion emulator.
2 From a terminal
cd AwesomeProject
react-native run-android # it loads in genymotion and fails with bundle error
react-native start > /dev/null 2>&1 & # from dsissitka
adb reverse tcp:8081 tcp:8081 # from dsissitka
3 Reload from emulator.
It loads!
I can now begin developing.
回答8:
Delete the App from your phone! I tried several steps, but that did it eventually.
- If you tried to run your app before but failed, delete it from your android device.
- Run
$ react-native run-android
- Open the React Rage Shake Menu from within your app on your android device, go to
Dev Settings
and then toDebug server host & port for device
. There enter your server IP (IP of your computer) and host8081
, e.g.192.168.50.35:8081
. On a mac you can find the IP of your computer atSystem Preferences -> Network -> Advanced... -> TCP/IP -> IPv4 Address
. - Open the Rage Shake Menu again and click
Reload JS
.
回答9:
Apparently adb reverse was introduced in Android 5.0
Getting "error: closed" twice on "adb reverse"
I guess we have to go ahead with kzzzf's answer
回答10:
I don't have enough reputation to comment, but this is referring to dsissitka's answer. It works on Windows 10 as well.
To reiterate, the commands are:
cd (App Dir)
react-native start > /dev/null 2>&1 &
adb reverse tcp:8081 tcp:8081
回答11:
Here are the simple steps to run your app on android(release):
1. Go to your application root.
2. Run this command.
react-native bundle --platform android --dev false --entry-file index.android.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res
All your files are copied.
3. Create signed APK.
Open android studio.
Build > Generate Signed APK > [Fill required details, keystroke has to be generated before this step]
Your APK should be generated without any errors. Install on your device and this should work without any issues.
You can also connect your device and directly hit Run icon on android studio for testing.
Generating Keystroke:
Goto C:\Program Files\Java\jdkx.x.x_x\bin
Run
keytool -genkey -v -keystore d:\my_private_key.keystore -alias my-key-alias -keyalg RSA -keysize 2048 -validity 10000
It will probably ask you to fill in some details. Do it and your have your keystroke file(my_private_key.keystore) which can be used to sign your apk.
回答12:
I was getting this on Linux after stopping down the react-native run-android
process. Seems the node server is still running so the next time you run it, it won't run properly and your app can't connect.
The fix here is to kill the node process which is running in an Xterm which you can kill by ctrl-c
ing that window (easier) or you can find it using lsof -n -i4TCP:8081
then kill -9 PID
.
Then run react-native run-android
again.
回答13:
Check your wifi connection.
Another possibility could be you are either not connected to wifi, connected to the wrong network, or the ip address is wrong in your dev settings. For some reason, my android disconnected from the wifi and I started to get this error, unknowingly.
回答14:
Running on device
I have found another answer.
- adb reverse: only work on Android 5.0+ (API 21).
- Another: Open the Developer menu by shaking the device, go to Dev Settings, Go to Debug server host for device, type in your machine's IP address and the port of the local dev server
回答15:
An update
Now on windows no need to run react-native start. The packager will run automatically.
回答16:
One important thing to check that no one has mentioned so far: Check your local firewall, make sure it's turned OFF.
See my response here: https://stackoverflow.com/a/41400708/1459275
回答17:
I am using Ubuntu and Android only, and I was unable to get it running. I found a really simple solution which is to update your package.json file, changing this lines:
"scripts": {
"start": "node node_modules/react-native/local-cli/cli.js start"
},
to
"scripts": {
"start": "adb reverse tcp:8081 tcp:8081 && node node_modules/react-native/local-cli/cli.js start"
},
And then you run the server by typing
npm run start
This ensures the android device looks for the node server on your computer instead of locally on the phone.
回答18:
The initial question was about reloading the application in a phyisical device.
When you're debugging the application in a physical device (ie via adb), you can reload the JS bundle by clicking on the top left "action" button of your device. This will open the option menu (Reload, Debug JS remotely...).
Hope this helps.
回答19:
This error can easily resolved by following steps:
//run the command at /android sdk / platforms-tool folder
adb reverse tcp:8081 tcp:8081
//now come to root folder of your app
1. npm start
2. create 'assets' folder inside rootApp/android/app/src/main/
3. curl "http://localhost:8081/index.android.bundle?platform=android" -o "android/app/src/main/assets/index.android.bundle"
4. make sure anyone physical or virtual device attached is running.
5. react-native run-android
回答20:
You can follow the instruction mentioned on the official page to fix this issue. This issue occur on real device because the JS bundle is located on your development system and the app inside your real device is not aware of it's location.
回答21:
In new React Native (for sure 0.59) debug config is inside android/app/src/debug/res/xml/react_native_config.xml
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
<domain-config cleartextTrafficPermitted="true">
<domain includeSubdomains="false">localhost</domain>
<domain includeSubdomains="false">10.0.2.2</domain>
<domain includeSubdomains="false">10.0.3.2</domain>
</domain-config>
</network-security-config>
回答22:
Start the two terminal on the same and 1st terminal run react-native start and second terminal react-native run-android this problem are solve in simply way. And best of luck
回答23:
Running npm start from react-native directory worked out for me.
来源:https://stackoverflow.com/questions/32572399/android-failed-to-load-js-bundle