Problem solved, I&#39;ve not added the **index.html**. Which is point out in the **web.xml**


[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/8OoEx.png

**Note:** a project may have more than one **web.xml** file.

if there are another **web.xml** in 

&gt; src/main/webapp/WEB-INF

Then you might need to add another index (this time **index.jsp**) to 

&gt; src/main/webapp/WEB-INF/pages/

Hope this helps. From eclipse, you right click the project -&gt; Run As -&gt; Run on Server and then it worked for me. I used Eclipse Jee Neon and Apache Tomcat 9.0. :)


I just removed the head portion in index.html file and it worked fine.[This is the head tag in html file][1]


  [1]: https://i.stack.imgur.com/d80sE.png

I am receiving the error:
`ValueError: Wrong number of items passed 3, placement implies 1`, and I am struggling to figure out where, and how I may begin addressing the problem.

I don&#39;t really understand the meaning of the error; which is making it difficult for me to troubleshoot.  I have also included the block of code that is triggering the error in my Jupyter Notebook.

The data is tough to attach; so I am not looking for anyone to try and re-create this error for me.  I am just looking for some feedback on how I could address this error.


    KeyError                                  Traceback (most recent call last)
    C:\Users\brennn1\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\indexes\base.py in get_loc(self, key, method, tolerance)
       1944             try:
    -&gt; 1945                 return self._engine.get_loc(key)
       1946             except KeyError:
    
    pandas\index.pyx in pandas.index.IndexEngine.get_loc (pandas\index.c:4154)()
    
    pandas\index.pyx in pandas.index.IndexEngine.get_loc (pandas\index.c:4018)()
    
    pandas\hashtable.pyx in pandas.hashtable.PyObjectHashTable.get_item (pandas\hashtable.c:12368)()
    
    pandas\hashtable.pyx in pandas.hashtable.PyObjectHashTable.get_item (pandas\hashtable.c:12322)()
    
    KeyError: &#39;predictedY&#39;
    
    During handling of the above exception, another exception occurred:
    
    KeyError                                  Traceback (most recent call last)
    C:\Users\brennn1\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\internals.py in set(self, item, value, check)
       3414         try:
    -&gt; 3415             loc = self.items.get_loc(item)
       3416         except KeyError:
    
    C:\Users\brennn1\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\indexes\base.py in get_loc(self, key, method, tolerance)
       1946             except KeyError:
    -&gt; 1947                 return self._engine.get_loc(self._maybe_cast_indexer(key))
       1948 
    
    pandas\index.pyx in pandas.index.IndexEngine.get_loc (pandas\index.c:4154)()
    
    pandas\index.pyx in pandas.index.IndexEngine.get_loc (pandas\index.c:4018)()
    
    pandas\hashtable.pyx in pandas.hashtable.PyObjectHashTable.get_item (pandas\hashtable.c:12368)()
    
    pandas\hashtable.pyx in pandas.hashtable.PyObjectHashTable.get_item (pandas\hashtable.c:12322)()
    
    KeyError: &#39;predictedY&#39;
    
    During handling of the above exception, another exception occurred:
    
    ValueError                                Traceback (most recent call last)
    &lt;ipython-input-95-476dc59cd7fa&gt; in &lt;module&gt;()
         26     return gp, results
         27 
    ---&gt; 28 gp_dailyElectricity, results_dailyElectricity = predictAll(3, 0.04, trainX_dailyElectricity, trainY_dailyElectricity, testX_dailyElectricity, testY_dailyElectricity, testSet_dailyElectricity, &#39;Daily Electricity&#39;)
    
    &lt;ipython-input-95-476dc59cd7fa&gt; in predictAll(theta, nugget, trainX, trainY, testX, testY, testSet, title)
          8 
          9     results = testSet.copy()
    ---&gt; 10     results[&#39;predictedY&#39;] = predictedY
         11     results[&#39;sigma&#39;] = sigma
         12 
    
    C:\Users\brennn1\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\frame.py in __setitem__(self, key, value)
       2355         else:
       2356             # set column
    -&gt; 2357             self._set_item(key, value)
       2358 
       2359     def _setitem_slice(self, key, value):
    
    C:\Users\brennn1\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\frame.py in _set_item(self, key, value)
       2422         self._ensure_valid_index(value)
       2423         value = self._sanitize_column(key, value)
    -&gt; 2424         NDFrame._set_item(self, key, value)
       2425 
       2426         # check if we are modifying a copy
    
    C:\Users\brennn1\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\generic.py in _set_item(self, key, value)
       1462 
       1463     def _set_item(self, key, value):
    -&gt; 1464         self._data.set(key, value)
       1465         self._clear_item_cache()
       1466 
    
    C:\Users\brennn1\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\internals.py in set(self, item, value, check)
       3416         except KeyError:
       3417             # This item wasn&#39;t present, just insert at end
    -&gt; 3418             self.insert(len(self.items), item, value)
       3419             return
       3420 
    
    C:\Users\brennn1\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\internals.py in insert(self, loc, item, value, allow_duplicates)
       3517 
       3518         block = make_block(values=value, ndim=self.ndim,
    -&gt; 3519                            placement=slice(loc, loc + 1))
       3520 
       3521         for blkno, count in _fast_count_smallints(self._blknos[loc:]):
    
    C:\Users\brennn1\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\internals.py in make_block(values, placement, klass, ndim, dtype, fastpath)
       2516                      placement=placement, dtype=dtype)
       2517 
    -&gt; 2518     return klass(values, ndim=ndim, fastpath=fastpath, placement=placement)
       2519 
       2520 # TODO: flexible with index=None and/or items=None
    
    C:\Users\brennn1\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\internals.py in __init__(self, values, placement, ndim, fastpath)
         88             raise ValueError(&#39;Wrong number of items passed %d, placement &#39;
         89                              &#39;implies %d&#39; % (len(self.values),
    ---&gt; 90                                              len(self.mgr_locs)))
         91 
         92     @property
    
    ValueError: Wrong number of items passed 3, placement implies 1

My code is as follows:

    def predictAll(theta, nugget, trainX, trainY, testX, testY, testSet, title):
    
        gp = gaussian_process.GaussianProcess(theta0=theta, nugget =nugget)
        gp.fit(trainX, trainY)
    
        predictedY, MSE = gp.predict(testX, eval_MSE = True)
        sigma = np.sqrt(MSE)
        
        results = testSet.copy()
        results[&#39;predictedY&#39;] = predictedY
        results[&#39;sigma&#39;] = sigma
    
        print (&quot;Train score R2:&quot;, gp.score(trainX, trainY))
        print (&quot;Test score R2:&quot;, sklearn.metrics.r2_score(testY, predictedY))
    
        plt.figure(figsize = (9,8))
        plt.scatter(testY, predictedY)
        plt.plot([min(testY), max(testY)], [min(testY), max(testY)], &#39;r&#39;)
        plt.xlim([min(testY), max(testY)])
        plt.ylim([min(testY), max(testY)])
        plt.title(&#39;Predicted vs. observed: &#39; + title)
        plt.xlabel(&#39;Observed&#39;)
        plt.ylabel(&#39;Predicted&#39;)
        plt.show()
        
        return gp, results
    
    gp_dailyElectricity, results_dailyElectricity = predictAll(3, 0.04, trainX_dailyElectricity, trainY_dailyElectricity, testX_dailyElectricity, testY_dailyElectricity, testSet_dailyElectricity, &#39;Daily Electricity&#39;)



ValueError: Wrong number of items passed - Meaning and suggestions?

I just spent a week reading the Rust Book, and now I&#39;m working on my first program, which returns the filepath to the system wallpaper:

    pub fn get_wallpaper() -&gt; &amp;str {
        let output = Command::new(&quot;gsettings&quot;);
        // irrelevant code
        if let Ok(message) = String::from_utf8(output.stdout) {
            return message;
        } else {
            return &quot;&quot;;
        }
    }

I&#39;m getting the error `expected lifetime parameter on &amp;str` and I know Rust wants an input `&amp;str` which will be returned as the output because any `&amp;str` I create inside the function will be cleaned up immediately after the function ends.

I know I can sidestep the issue by returning a `String` instead of a `&amp;str`, and many answers to similar questions have said as much. But I can also seemingly do this:

    fn main() {
        println!(&quot;message: {}&quot;, hello_string(&quot;&quot;));
    }
    
    fn hello_string(x: &amp;str) -&gt; &amp;str {
        return &quot;hello world&quot;;
    }

to get a `&amp;str` out of my function. Can someone explain to me why this is bad and why I should never do it? Or maybe it&#39;s not bad and okay in certain situations?

Proper way to return a new string in Rust

I was following the tutorial on **o7planning** and got stuck at step 6:
 
http://o7planning.org/en/10169/java-servlet-tutorial

It&#39;s just a simple project that show *HelloWorld* but for some reason I keep getting `404` error. Detail:

[![enter image description here][1]][1]
However the Tomcat welcome page showing properly.

[![Tomcat welcome page][2]][2]


Here solutions that I&#39;ve tried so far (and they are NOT working):

&gt; Right-click project -&gt; properties -&gt; Project Facets -&gt; Runtimes -&gt; checked &quot;Apache Tomcat v9.0&quot; -&gt; Apply -&gt; finish.
&gt;
&gt; Server tab -&gt; Right-click &quot;Tomcat v9.0...&quot; -&gt; properties -&gt; switch location -&gt; Choose &quot;Use tomcat installation&quot; on &quot;Server locations&quot; panel.


  [1]: https://i.stack.imgur.com/ASMwv.png
  [2]: https://i.stack.imgur.com/ybGTj.png

Tomcat 404 error: The origin server did not find a current representation for the target resource or is not willing to disclose that one exists

I was following the tutorial on o7planning and got stuck at step 6:
<a href="http://o7planning.org/en/10169/java-servlet-tutorial" target="_blank" rel="noopener noreferrer">http://o7planning.org/en/10169/java-servlet-tutorial</a>
It's just a simple project that show HelloWorld but for some reason I keep getting <code>404</code> error. Detail:
<a href="https://i.stack.imgur.com/ASMwv.png" target="_blank" rel="noopener noreferrer"><img src="https://i.stack.imgur.com/ASMwv.png" alt="enter image description here"></a>
However the Tomcat welcome page showing properly.
<a href="https://i.stack.imgur.com/ybGTj.png" target="_blank" rel="noopener noreferrer"><img src="https://i.stack.imgur.com/ybGTj.png" alt="Tomcat welcome page"></a>
Here solutions that I've tried so far (and they are NOT working):
> Right-click project -> properties -> Project Facets -> Runtimes -> checked "Apache Tomcat v9.0" -> Apply -> finish.
>
> Server tab -> Right-click "Tomcat v9.0..." -> properties -> switch location -> Choose "Use tomcat installation" on "Server locations" panel.

Using API21+ `Toolbar`:

    // Toolbar
    Toolbar toolbar = new Toolbar(this);
    toolbar.showOverflowMenu();

Would like to remove its shadow completely. `setElevation(0)` doesn&#39;t do anything since `getElevation()` already returns `0`.

There is Material Design reference:

https://material.io/guidelines/layout/structure.html#structure-toolbars

There is Develop Reference:

https://developer.android.com/reference/android/widget/Toolbar.html

But I don&#39;t see any info related to the shadow. `Toolbar` 

**Question:** how to remove/hide `Toolbar` shadow completely?

Remove android.widget.Toolbar shadow

The app I&#39;m working on shows some sensitive information that must not be shown on the &quot;Recent Tasks&quot; screen when stopping the app by pressing the home button.

I&#39;d like to blur the sensitive data in the screenshot or **show the app logo instead**.

I am aware of the following approaches but they don&#39;t fit my requirements:

 - Setting the actvitie&#39;s &lt;code&gt;android:excludeFromRecents&lt;/code&gt; to true in the manifiest prevents the app from being shown at all in the recent tasks. This would disrupt the user experience.
 - Using &lt;code&gt;FLAG_SECURE&lt;/code&gt; results in a blank card on the recents tasks screen. (https://stackoverflow.com/questions/9822076/how-do-i-prevent-android-taking-a-screenshot-when-my-app-goes-to-the-background) I don&#39;t like the blank screen. However, I&#39;ll stick to this solution if there is no workaround.
 - Overriding &lt;code&gt;onCreateThumbnail&lt;/code&gt; seems like the ideal solution but, unfortunately, doesn&#39;t work as it&#39;s currently not invoked by the OS :( (https://code.google.com/p/android/issues/detail?id=29370)

And then there are some workarounds that I tried out but that didn&#39;t work as hoped:

 - Start a new activity that shows the app logo in &lt;code&gt;onPause&lt;/code&gt; so that it&#39;s screenshot is shown instead of the actual activitie&#39;s one. But the new activity takes too long to open and it disrupts the user experience.
 - Set the activitie&#39;s content view to an image of the app logo in &lt;code&gt;onPause&lt;/code&gt;. That seemed like a great solution to me. Unfortunately, the screenshot for the recent tasks screen is taken at an unspecified time. During testing the app logo quickly appears before the app is closed when pressing &#39;Home&#39; but the resulting screenshot shows the activity a short time before that.
 - Removing the sensitive data from the widgets (e.g. &lt;code&gt;textView.setText(&quot;&quot;)&lt;/code&gt;) has the same problem of screenshot timing just mentioned.

Any alternative ideas or solutions to the listed workarounds?



Android: Customizing recent apps thumbnail (screenshot by default)

To use Hamcrest with JUnit 4 we use an `assertThat()` function. However, JUnit 5 is no longer going to have an `assertThat()` function. How do I use Hamcrest without an `assertThat()`?

How do I use Hamcrest with JUnit 5 when JUnit 5 doesn&#39;t have an assertThat() function?

The `@BeforeAll` annotation marks a method to run before all tests in a *class*.

http://junit.org/junit5/docs/current/user-guide/#writing-tests-annotations

But is there a way to run some code before *all* tests, in all classes? 

I want to ensure that tests use a certain set of database connections, and the global one-time setup of these connections must occur **before** running **any** tests.


In JUnit 5, how to run code before all tests

I need to modify strings similar to &quot;&#188; cups of sugar&quot; to &quot;cups of sugar&quot;, meaning replacing all fraction symbols with &quot;&quot;.

I have referred to this [post][1] and managed to remove &#188; using this line:

    itemName = itemName.replaceAll(&quot;\u00BC&quot;, &quot;&quot;);

but how do I replace every possible fraction symbol out there?
  [1]: https://stackoverflow.com/questions/16838352/how-to-remove-%C2%BC-and-%C2%BD-from-a-string

Removing all fraction symbols like “&#188;” and “&#189;” from a string

I am receiving below error while running my Jersey API in Tomcat 8.5.11 which is causing my API to stop:

&gt; HTTP Status 500 - Servlet.init() for servlet Jersey REST Service threw
&gt; exception
&gt; 
&gt; type Exception report
&gt; 
&gt; message Servlet.init() for servlet Jersey REST Service threw exception
&gt; 
&gt; description The server encountered an internal error that prevented it
&gt; from fulfilling this request.
&gt; 
&gt; exception
&gt; 
&gt; javax.servlet.ServletException: Servlet.init() for servlet Jersey REST
&gt; Service threw exception
&gt; 	org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474)
&gt; 	org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
&gt; 	org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
&gt; 	org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
&gt; 	org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
&gt; 	org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
&gt; 	org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798)
&gt; 	org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434)
&gt; 	org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
&gt; 	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
&gt; 	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
&gt; 	org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
&gt; 	java.lang.Thread.run(Thread.java:745)
&gt; 
&gt; root cause
&gt; 
&gt; java.lang.IllegalStateException: InjectionManagerFactory not found.
&gt; 	org.glassfish.jersey.internal.inject.Injections.lookupInjectionManagerFactory(Injections.java:97)
&gt; 	org.glassfish.jersey.internal.inject.Injections.createInjectionManager(Injections.java:89)
&gt; 	org.glassfish.jersey.server.ApplicationHandler.&lt;init&gt;(ApplicationHandler.java:282)
&gt; 	org.glassfish.jersey.servlet.WebComponent.&lt;init&gt;(WebComponent.java:335)
&gt; 	org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:178)
&gt; 	org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:370)
&gt; 	javax.servlet.GenericServlet.init(GenericServlet.java:158)
&gt; 	org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474)
&gt; 	org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
&gt; 	org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
&gt; 	org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
&gt; 	org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
&gt; 	org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
&gt; 	org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798)
&gt; 	org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434)
&gt; 	org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
&gt; 	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
&gt; 	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
&gt; 	org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
&gt; 	java.lang.Thread.run(Thread.java:745)

The application is build with the following dependencies with gradle:

    dependencies {
        compile (
        	// REST
        	&quot;org.glassfish.jersey.containers:jersey-container-servlet:2.+&quot;,
        	&quot;javax.servlet:javax.servlet-api:4.+&quot;,
        	// REST Token
        	&quot;org.bitbucket.b_c:jose4j:0.+&quot;,
        	// MongoDB
        	&quot;org.hibernate.ogm:hibernate-ogm-bom:5.+&quot;,
        	&quot;org.hibernate.ogm:hibernate-ogm-infinispan:5.+&quot;,
        	&quot;org.hibernate.javax.persistence:hibernate-jpa-2.1-api:1.+&quot;,
        	&quot;org.jboss.spec.javax.transaction:jboss-transaction-api_1.2_spec:1.+&quot;,
        	&quot;org.jboss.narayana.jta:narayana-jta:5.+&quot;,
        	&quot;org.jboss:jboss-transaction-spi:7.+&quot;,
        	&quot;log4j:log4j:1.+&quot;,
        	&quot;org.hibernate.ogm:hibernate-ogm-mongodb:5.+&quot;,
        	&quot;org.bouncycastle:bcprov-jdk15on:1.+&quot;
        ) }

This downloads `jersey-common-2.26-b04.jar` which contains the missing class under `/org/glassfish/jersey/internal/inject/InjectionManagerFactory`. The jar file is deployed into the Tomcat folder under `WEB-INF/lib`

What can be wrong here? The gradle script worked the last few month with the same Tomcat version.

Jersey stopped working with InjectionManagerFactory not found

How to handle `Image.network` when the url is wrong or the destination leads to 404.

for example try 

    Image.network(&#39;https://image.tmdb.org/t/p/w92&#39;)

Flutter how to handle Image.network error (like 404 or wrong url)

I have deployed my site with Netlify, and I’m having trouble with the routing. 

Here is my website: https://redux-co.netlify.com/

And my GitHub repo: https://github.com/jenna-m/redux-co

Specifically, if a user navigates to any page besides the home page and refreshes the page, the default Netlify 404 renders. From the 404 page, if I navigate back to the home page and refresh, the home page is rendered.

Also, my custom 404 page isn’t working as it does when I’m on `localhost:3000`, but I would like to get this refresh issue figured out first before dealing with my custom 404 component.

I’m using React and react-router, and I understand that since I’m using react-router, my website won’t deploy right out of the box.


----------


This is my `_redirects` file, which is in the `/public` folder with  my `index.html` file:

``` javascript
/*    /index.html   200
```


This is my `“build”` located in `package.json`:
``` javascript
…
&#160;&#160;&quot;scripts&quot;:&#160;{
&#160;&#160;&#160;&#160;&quot;start&quot;:&#160;&quot;react-scripts&#160;start&quot;,
&#160;&#160;&#160;&#160;&quot;build&quot;:&#160;&quot;react-scripts&#160;build&#160;&amp;&amp;&#160;cp&#160;build/index.html&#160;build/404.html&quot;,
&#160;&#160;&#160;&#160;&quot;test&quot;:&#160;&quot;react-scripts&#160;test&quot;,
&#160;&#160;&#160;&#160;&quot;eject&quot;:&#160;&quot;react-scripts&#160;eject&quot;
&#160;&#160;}
…
```


----------


I have read about other people experiencing this and what they’ve done to overcome the problem. This is what I’ve referenced so far…

https://www.freecodecamp.org/news/how-to-deploy-a-react-application-to-netlify-363b8a98a985/

https://hugogiraudel.com/2017/05/13/using-create-react-app-on-netlify/

This person was using Vue and not React, but I gave these solutions an attempt anyway:

https://github.com/vuejs/vuepress/issues/457#issuecomment-390206649

https://github.com/vuejs/vuepress/issues/457#issuecomment-463745656

Content Type	Original Author	Original Content on Stackoverflow
Question	Lê Quang Bảo	View Question on Stackoverflow
Solution 1 - Java	Lê Quang Bảo	View Answer on Stackoverflow
Solution 2 - Java	Michael Joshua Ramos	View Answer on Stackoverflow

Tomcat 404 error: The origin server did not find a current representation for the target resource or is not willing to disclose that one exists

Java Problem Overview

Java Solutions

Solution 1 - Java

Solution 2 - Java

Proper way to return a new string in Rust

ValueError: Wrong number of items passed - Meaning and suggestions?

Attributions