2017-07-29T14:24:32Z

Below is the request I received from server log. I am worried this may trigger some crash. The server is a simple express dev server.

"GET login.cgi HTTP/1.0"

How do I use curl to duplicate the above exact request?

no path
login.cgi
HTTP 1.0

2015-04-27T04:14:39Z

When I close a java program in intellJ, the following log appears in the console: "Process finished with exit code 130"

Some times, the code is "1".

I know this is the very basic, but I googled Internet and still couldn't find the explanation for the exit code.

What does the code mean? Where can I find the explanation?

2015-07-05T09:10:21Z

I am plotting a line chart using jFreeChart, which is a series of (x, y) value connected by a straight line.

But the problem is the shape, a circle or a rect that represents a data point is too big, since I have a lot of values in one series. You can see how it looks like in this screenshot:

Also, I learned the shapes that represent data point do not scale as the rest of the plot does when I resize the chart panel.

Question:

How to make the shape(the circles and rects that represent data point) smaller so that they won't clog together?

Here is my code to generate the chart, and I used a customized renderer to draw different color for different part of the line in one data series.

    private JFreeChart createChart(XYDataset dataCollection) {

    // create the chart...
    JFreeChart chart = ChartFactory.createXYLineChart(
            fileName, // chart title
            "Count", // x axis label
            "Price", // y axis label
            dataCollection, // data
            PlotOrientation.VERTICAL,
            true, // include legend
            true, // tooltips
            false // urls
    );

    // customize chart
    XYPlot plot = (XYPlot) chart.getPlot();
    // find out the max and min value for price series
    XYSeriesCollection collection = (XYSeriesCollection)plot.getDataset();
    XYSeries priceSeries = collection.getSeries(0);
    double maxY = priceSeries.getMaxY();
    double minY = priceSeries.getMinY();
    // set max and min for range axis (y axis)
    NumberAxis rangeAxis = (NumberAxis)plot.getRangeAxis();
    rangeAxis.setRange(minY, maxY);

    XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer() {

        public Color getItemColor(int series, int item) {
            // modify code here to change color for different part of the line in one serie line
            if(series == 1) {
                System.out.println("getting color at: " + item);
                int isBuy = 0;
                if(item < kFilter.buySellSignal.size()) {
                    isBuy = kFilter.buySellSignal.get(item);
                }

                if(isBuy == 1) {
                    return Color.red;
                } else {
                    return Color.green;
                }
            } else {
                return Color.yellow;
            }



        }

        @Override
        protected void drawFirstPassShape(Graphics2D g2, int pass, int series, int item, Shape shape) {
            super.drawFirstPassShape(g2, pass, series, item, shape);

            //g2.setStroke(getItemStroke(series, item));
            Color c1 = getItemColor(series, item - 1);
            Color c2 = getItemColor(series, item);

            GradientPaint linePaint = new GradientPaint(0, 0, c1, 0, 300, c2);
            g2.setPaint(linePaint);
            g2.draw(shape);
        }
    };

    plot.setRenderer(renderer);

    return chart;
}

2023-01-19T20:30:29Z

import { useQuery } from "vue-query";
const { isLoading, data /* read only */, error, isError, refetch } = useQuery("todo", todo)

I just found out data returned by vue-query is read only. Vue-query is similary project to React-query. You can find it here.
If I do data.todoList.push(newTodo) then I got the following warning

[Vue warn] Set operation on key "xxx" failed: target is readonly

My question is 1) How do I change the value returned by vue-query? 2) If I need to change the returned data, what is the best way to do it?

2016-04-01T18:46:46Z

I've learned Java language features in the past 3 months and compiled many projects using IntelliJ. The experience was great! But when I trying to learn Java Spring, I couldn't even get it running.

To run Spring, they introduce a new thing called Gradle. Why do we need it? I just couldn't figure out what Gradle is AFTER READING document on Gradle official site.

My previous Java projects, class, packages was running perfectly. Why they invented Gradle? What is this thing?

2014-07-06T14:01:26Z

I am writing spec for testing RESTful api. The module I use to make http request is standard http module in nodejs.

If I don't specify the 'Content-Length' in header, then the request is made successfully, but I specify the length by

options.headers['Content-Length'] = post_data.length;

, then it is a bad request with 400 error code. I searched stackoverflow for Content-Length related question, but got no inspiration so far. I tried length +1, and just 100, all ending with same bad request.

Below is my code. Can you tell me what is the problem?

var options = {
  hostname: hostname,
  port: port,
  headers: {
        'Content-Type': 'application/json',
        'Cache-Control': 'no-cache'
        // 'Content-Length': post_data.length
    }
};

describe('API Testing Function', function () {

    db.bind('user');

    describe('POST /api/user', function () {
        it('should return 400 when password is not present', function (done) {

            options.method = 'POST';
            options.path = '/api/user';
            var post_data = JSON.stringify({email:'111@email.com'});
            options.headers['Content-Length'] = post_data.length; // error here
            // if I delete above line, then it is totally good request. 

            var req = http.request(options, function(res){

                res.on('data', function(chunk){
                    // console.log('BODY:' + chunk);
                    var result = JSON.parse(chunk);
                    assert.equal(400, result.code);
                    done();
                });
            });
            req.write(post_data, 'utf8');
            req.end();
        });
    });
});

2018-08-06T21:05:05Z

Below is my code. I don't think there is any problem.

How can I fool codacy? If I can't use obj[key], then what the hell is this thing? There is no way I can avoid [].

handleClick = (e, titleProps) => {
     const { index } = titleProps
     const newVal = this.state.activeIndexObj[index]? false: true
     let activeIndexObj = {...this.state.activeIndexObj}
     activeIndexObj[index] = newVal
     // Generic Object Injection Sink (security/detect-object-injection)

2016-09-21T17:17:44Z

I encountered new() in the official document here about generics.

Here is the code context:

function create<T>(c: { new(): T; } ): T {
    return new c();
}

The above code is transpiled to the following JavaScript code:

function create(c) {
    return new c();
}

new() is illegal syntax in JavaScript. What does it mean in TypeScript?

Furthermore, what does {new(): T; } mean? I know it must be a type, but how?

2023-07-12T15:05:06Z

type Activity = {
  activity: string
  type: string
  participants: number
  price: number
  link: string
  key: string
  accessibility: number
}

async function fetchOne(): Promise<Activity> {
  const url = "https://www.boredapi.com/api/activity"
  const res: Activity = await fetch(url).then(res => (res.json()))
  // Unsafe assignment of an `any` value.eslint@typescript-eslint/no-unsafe-assignment
  // how to fix this? 
  return res
}

I got :

Unsafe assignment of an any value.eslint@typescript-eslint/no-unsafe-assignment

Any suggestion on how to fix this?

2014-08-23T09:38:56Z

I'd like to find all *.html files in src folder and all its sub folders using nodejs. What is the best way to do it?

var folder = '/project1/src';
var extension = 'html';
var cb = function(err, results) {
   // results is an array of the files with path relative to the folder
   console.log(results);

}
// This function is what I am looking for. It has to recursively traverse all sub folders. 
findFiles(folder, extension, cb);

I think a lot developers should have great and tested solution and it is better to use it than writing one myself.

2014-01-13T04:42:42Z

In the Express generated code:

...
app.use(express.urlencoded());
app.use(express.methodOverride());
app.use(express.cookieParser('my secret cat'));
...

The method express.methodOverride() is unfamiliar to me. I read the doc Connect document here, but I still miss the whole picture.

My question is:

In what situation do we need to override a method (GET, POST, PUT, and DELETE) using express.methodOverride()?

I found an relevant answer here, but my follow up question is:

If no express.methodOverride(), I can't use app.put(), app.delete(), app.get(), app.post() in Express. Is this correct?

2018-05-04T17:37:37Z

Consider:

const GET_DOGS = gql`
  {
    dogs {
      id
      breed
    }
  }
`;

I found this new syntax from here.

What is the explanation for this syntax? Where can I find detail about it?

2016-06-25T16:25:33Z

I am learning JSP programing which requires Tomcat. I followed some tutorials but failed to install successfully(Probably some step is not clear match to my situation)

Then I found out you can install easily by this command line:

brew install tomcat

It looks install is successful,

My challenge is after install, I don't know where it is on my hard drive. Therefore, can't configure it in IntelliJ.

My question is:

How do I find out where Tomcat is installed by brew on MacOS?

Thanks!

2016-10-15T16:05:04Z

I've just read this article about what is HTTPS service, and understand the basic of https.

When requesting https content, the server will send a public key to browser, so that every time, the browser receive data will decrypted with the public key.

My question is what is CA certificate for? Why do we need it?

2020-02-07T18:17:36Z

I've read the document here, and from previous question, I can see

The setIndex function is used to specify triangle indices that reference the vertex attribute buffers on the BufferGeometry.

I think I understand 50% of these concepts, but in this interleaved example, (code is here) What is the purpose of setting index (I know it is specifying triangle indices)? but why?

var indices = new Uint16Array( [
            0, 1, 2,
            2, 1, 3,
            4, 5, 6,
            6, 5, 7,
            8, 9, 10,
            10, 9, 11,
            12, 13, 14,
            14, 13, 15,
            16, 17, 18,
            18, 17, 19,
            20, 21, 22,
            22, 21, 23
        ] );

geometry.setIndex( new THREE.BufferAttribute( indices, 1 ) );

My understanding is there are 24 vertexes, and the set index tells the renderer to use vertex at a specific index (not natural order) to arrange a triangle. But why is a new arrangement needed? Do I have to do setIndex every time in my own code?

2017-03-17T19:56:37Z

I've read this official document about Vuejs animation. But using it css hooks, I can only make element appear/disappear with fade and different duration.

<div id="demo">
  <button v-on:click="show = !show">
    Toggle
  </button>
  <transition name="fade">
    <p v-if="show">hello</p>
  </transition>
</div>


.fade-enter-active, .fade-leave-active {
  transition: opacity .5s
}
.fade-enter, .fade-leave-to /* .fade-leave-active in <2.1.8 */ {
  opacity: 0
}

How to use Vuejs Animation to create a sliding effect? Like the one here. Is it possible? Please provide some sample code.

2017-06-08T19:29:33Z

My Jenkins is not run in Docker container, just tradional install to VPS. I got the following error when executing a simple test project. I am using Ubuntu 14, java 7, and stable Jenkins. I tried all methods I can find on google, but can't get it work.

I am trying to execute this shell

docker build --pull=true -t nick/hello-jenkins:$GIT_COMMIT .

After code change.

Here is error:

Got permission denied while trying to connect to the Docker daemon socket at unix: ....

Started by user nicolas xu
Building in workspace /var/lib/jenkins/workspace/hello-Jenkins
 > git rev-parse --is-inside-work-tree # timeout=10
Fetching changes from the remote Git repository
 > git config remote.origin.url https://github.com/nicolasxu/hello-nick-jenkins.git # timeout=10
Fetching upstream changes from https://github.com/nicolasxu/hello-nick-jenkins.git
 > git --version # timeout=10
 > git fetch --tags --progress https://github.com/nicolasxu/hello-nick-jenkins.git +refs/heads/*:refs/remotes/origin/*
 > git rev-parse refs/remotes/origin/master^{commit} # timeout=10
 > git rev-parse refs/remotes/origin/origin/master^{commit} # timeout=10
Checking out Revision d94ae21a8a2cf58ffc790dcad15bd851fb17df5a (refs/remotes/origin/master)
 > git config core.sparsecheckout # timeout=10
 > git checkout -f d94ae21a8a2cf58ffc790dcad15bd851fb17df5a
 > git rev-list d94ae21a8a2cf58ffc790dcad15bd851fb17df5a # timeout=10
[hello-Jenkins] $ /bin/sh -xe /tmp/hudson5076309502904684976.sh
+ docker build --pull=true -t nick/hello-jenkins:d94ae21a8a2cf58ffc790dcad15bd851fb17df5a .
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post http://%2Fvar%2Frun%2Fdocker.sock/v1.27/build?buildargs=%7B%7D&cachefrom=%5B%5D&cgroupparent=&cpuperiod=0&cpuquota=0&cpusetcpus=&cpusetmems=&cpushares=0&dockerfile=Dockerfile&labels=%7B%7D&memory=0&memswap=0&networkmode=default&pull=1&rm=1&shmsize=0&t=nick%2Fhello-jenkins%3Ad94ae21a8a2cf58ffc790dcad15bd851fb17df5a&ulimits=null: dial unix /var/run/docker.sock: connect: permission denied
Build step 'Execute shell' marked build as failure
Finished: FAILURE

I can run 'docker' in console as root no problem, why jenkins can't try a shell command which runs 'docker'? What is going on? Totally confused.......

2022-11-11T18:01:27Z

Below is official example in React document. The official explanation is

The problem is that inside the setInterval callback, the value of count does not change, because we’ve created a closure with the value of count set to 0 as it was when the effect callback ran.

Can you show me where is the closure? I don't understand why the closure making the counter only reaches 2. I know closure, useEffect(), ()=> {} will not create a closure, but I don't understand how those concepts play together in this example to make the counter bug.

import React, { useEffect, useState } from "react";

function Counter() {
  const [count, setCount] = useState(1);

  useEffect(() => {
    const id = setInterval( () => {
      console.log("interval callback triggered");
      setCount(count + 1); // This effect depends on the `count` state
    }, 1000);
    return () => clearInterval(id);
  }, []); // 🔴 Bug: `count` is not specified as a dependency

  return <h1>{count}</h1>;
}

export default Counter;

2017-12-01T22:01:40Z

'react-router-dom' has refresh function here, but I don't know how to call this method, also their well formatted document doesn't bother to explain this.

window.location.reload() doesn't work for me, because it wipes out the app store as well. I changed some data, and then need to reload the route with updated data.

I also read this: https://github.com/ReactTraining/react-router/issues/1982 https://github.com/ReactTraining/react-router/issues/2243

this thread is exactly discussing my question: https://github.com/ReactTraining/react-router/issues/4056

and still clueless how to do it. This basic function should not require too much effort, but after spending huge amount of effort, I can't reload current route.

here is my code:

@inject('store') @observer
export default class PasswordInput extends Component {
    constructor (props) {
        super(props)
        this.setPwd = this.setPwd.bind(this)
        this.submit = this.submit.bind(this)
    }

    componentWillMount() {
        this.case = this.props.store.case

        this.setState({refresh: false})
    }
    setPwd(e) {
        // console.log(e)
        this.case.pwd = e.target.value

    }
    submit() {
        console.log(this.props.caseId)
        this.setState({refresh: true})

    }

    render() {
        return (
            <Container>
                <div>{this.state.refresh}</div>
                { (this.state.refresh) && <Redirect refresh={true} to={'/cases/' + this.props.caseId}></Redirect>}
                <br />
                <Grid columns="three">
                    <Grid.Row>
                        <Grid.Column key={2}>
                            <Form>
                                <label>Enter Password</label>
                                <input placeholder="empty"  type="text" onChange={this.setPwd} value={this.case.pwd}></input>                               

                                <Button name="Save" color="green" size="mini" 
                                style={{marginTop:'1em'}}
                                onClick={this.submit}>
                                    Submit
                                </Button>                               
                            </Form>
                        </Grid.Column>
                    </Grid.Row>
                </Grid>
            </Container>
        )
    }
}

2013-12-24T02:08:54Z

I am confused about /\w\b\w/. I think it should match "e w" in "we we", since:

\w is word character which is "e"

\b is word broundary which is " " (space)

\w is another word which is "w"

So the match is "e w" in "we we". But...

/\w\b\w/ will never match anything, because a word character can never be followed by both a non-word and a word character.

I got this one from MDN:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions?redirectlocale=en-US&redirectslug=JavaScript%2FGuide%2FRegular_Expressions

I can't understand their explanation. Can you help me explain it in baby step? Thank you!

Nick

2016-06-24T17:32:11Z

I have very good pure Java basic knowledge. As long as there are no XML config and no project management tools involved, I am very good.

The things that really confused me are the project management tools, e.g.: Maven, Gradle.

I am learning Spring, and it is so confusing to me since it involves many XML files and there is no clear explanation for it.

I am learning Spring from this set of video tutorials, Lecture 6
Spring "Hello World".

I couldn't get a Spring hello world done because it requires a xxxxx.xml file to config the beans (Java object). To generate the XML files, I need to generate an XML file using a plugin on IntelliJ 2016.

The question is I can't find the plugin to generate a XML file for the bean by following this official tutorial. There is no such plugin called " Spring Support".

What should I do to generate the beans.xml? (The file to manage beans for Spring)

2017-06-08T17:14:46Z

Here are my jenkins config:

Error message:

/var/jenkins_home/.ssh/known_hosts [SSH] No Known Hosts file was found at /var/jenkins_home/.ssh/known_hosts. Please ensure one is created at this path and that Jenkins can read it.

No matter how much I tried it doesn't work. I've read this post, but still no solution.

2015-01-05T01:53:15Z

I use javascript often, and find underscorejs is very handy for manipulating data set, such as array or object.

I am very new to Java, and wonder if there is similar lib for Java?

2014-07-13T13:53:09Z

I have a callback function in before() which is for cleaning database. Is everything in before() guaranteed to finish before it() starts?

before(function(){
   db.collection('user').remove({}, function(res){}); // is it guaranteed to finish before it()? 
});

it('test spec', function(done){
  // do the test
});

after(function(){
});

2018-08-16T21:26:38Z

class ProductQuery(graphene.ObjectType):
    products = graphene.List(Product)

    def resolve_products(self, info):
        return get_all_products()

Above are my code for query all product with no param. What is I want to query product by manufacture_id? How to do I do the resolver?

There is no document on their official site.

2018-08-16T00:31:06Z

I am not interested in the stupid lint, which is not workable at all. It can do nothing but waste of my time.

I need a way to remove it and make sure ESLint will never appear again. What should I do? Please don't tell me to put a comment in my code to disable one warning. I need a solution to completely get rid of ESLint in vue cli 3 generated project.

2021-03-29T19:21:48Z

Caching request is a feature provided by browser itself. You can find the document here: https://developer.mozilla.org/en-US/docs/Web/API/Request/cache

// Download a resource with cache busting, to bypass the cache
// completely.
fetch("some.json", {cache: "no-store"})
  .then(function(response) { /* consume the response */ });

// Download a resource with cache busting, but update the HTTP
// cache with the downloaded resource.
fetch("some.json", {cache: "reload"})
  .then(function(response) { /* consume the response */ });

Is there a way to use browser built-in cache feature to cache Javascript AWS SDK result in browser?

For example, I want to use above MDN request object to cache the following AWS SDK api request:

    // Function invoked by button click
    function speakText() {
        // Create the JSON parameters for getSynthesizeSpeechUrl
        var speechParams = {
            OutputFormat: "mp3",
            SampleRate: "16000",
            Text: "",
            TextType: "text",
            VoiceId: "Matthew"
        };

        // Create the Polly service object and presigner object
        var polly = new AWS.Polly({apiVersion: '2016-06-10'});
        var signer = new AWS.Polly.Presigner(speechParams, polly)
    
        // Create presigned URL of synthesized speech file
        signer.getSynthesizeSpeechUrl(speechParams, function(error, url) {
        if (error) {
            document.getElementById('result').innerHTML = error;
        } else {
            document.getElementById('audioSource').src = url;
            document.getElementById('audioPlayback').load();
            document.getElementById('result').innerHTML = "Speech ready to play.";
        }
      });
    }

You can find the above code in AWS official tutorial here.

2020-02-04T22:39:07Z

Here are the documents for them:

InstancedMesh: https://threejs.org/docs/#api/en/objects/InstancedMesh

InstancedBufferGeometry: https://threejs.org/docs/#api/en/core/InstancedBufferGeometry

There are also some examples here: https://github.com/mrdoob/three.js/blob/dev/examples/webgl_buffergeometry_instancing.html

I know the basic concept about "instanced" in threejs and WebGL in general. My current understanding is Mesh is made of Geometry and Material (e.g. const plane = new THREE.Mesh(geometry, material)). Geometry does not contain color, but material does.

From the example above, I see they put color attribute in InstancedBufferGeometry, which is very confusing... geometry should not have color, right? Am I wrong?

geometry.setAttribute( 'offset', new THREE.InstancedBufferAttribute( new Float32Array( offsets ), 3 ) );
geometry.setAttribute( 'color', new THREE.InstancedBufferAttribute( new Float32Array( colors ), 4 ) );
geometry.setAttribute( 'orientationStart', new THREE.InstancedBufferAttribute( new Float32Array( orientationsStart ), 4 ) );
geometry.setAttribute( 'orientationEnd', new THREE.InstancedBufferAttribute( new Float32Array( orientationsEnd ), 4 ) );

My question is if I want to render 1000s of square planes with different color and move independently, should I use InstancedMesh or InstancedBufferGeometry? Why? Can they be used together?

2021-03-06T15:37:08Z

aaa = { :one => "eins", :two => "zwei", :three => "drei" }
bbb = { one: "eins", two: "zwei", three: "drei" }

above are valid ruby code. at line 1, why there is ":" before "one"? What's the meaning?

2021-02-23T21:46:07Z

There are hundreds of jest test files, and in each unit test files there could be mutiple describe block.

Is there a config or method to automatically run a block of code to do mock and setup before each describe block?

I know a brutal method which is to put beforeAll() in each describe block in hundreds of files, but it is too much editing. I tried the jest config object, but didn't find any useful option.

2024-06-03T22:46:52Z

does not work, it only produces more error

2024-03-30T21:45:55Z

My coverage is alway 0 by running your above yarn command.

2024-03-26T16:18:32Z

you didn't load dotenv. How could this work?

2024-03-13T17:38:10Z

is Autopilot still available? I can't find Autopilot in twilio console.

2024-02-12T19:40:18Z

It does not work for me.

2023-11-16T17:00:03Z

this is wrong answer

2023-10-31T20:57:42Z

oh my god... I this issue troubled me for hours! What stupid power buttion is it?

2023-07-12T15:12:45Z

@jcalz yes! You are right

2023-01-19T20:42:27Z

[...data.todoList, newTodo] does not work, same warning, no effect. I am not familiar with correct pattern for vue-query. Why they make the returned data read only?

2023-01-18T21:00:34Z

It does not work! it refreshes my page.

2022-11-11T18:20:03Z

So arrow function will create a closure, but not creating its scope. is this right? My previous statement "arrow function will not create closure" is wrong, right?

2022-10-24T18:16:13Z

I still don't understand what is well know symbol. It is so badly named.

2021-09-22T20:03:51Z

My offsetWidth is always 0 during elipsis. what is going one?

2021-01-23T19:13:22Z

@Pointy I see... it is called "spread syntax" in MDN. Thanks!

2021-01-23T17:59:28Z

@Syder Can you explain more?