I added the code to get data from the server using Asynchronous Callbacks (and log the error) and am surprised to find it gives a 404 error.
I had moved the code into a class ResponseFromServerPanel.
I don't know what I am missing.
Elf_g$ @ ConsoleLogger.java:33
:8888/stockwatcher.StockWatcher/stockPrices:1 Failed to load resource: the server responded with a status of 404 (Not Found)
ConsoleLogger.java:33 ERROR!!! com.google.gwt.user.client.rpc.StatusCodeException: 404 Not Found <html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>Error 404 Not Found</title>
</head>
<body><h2>HTTP ERROR 404</h2>
<p>Problem accessing /stockwatcher.StockWatcher/stockPrices. Reason:
<pre> Not Found</pre></p><hr><i><small>Powered by Jetty://</small></i><hr/>
</body>
</html>
Chrome browser developer tools console
Elf_g$ @ ConsoleLogger.java:33
$Md_g$ @ XMLHttpRequest.java:305
ckc_g$ @ RequestBuilder.java:418
lkc_g$ @ RequestBuilder.java:242
o3c_g$ @ RemoteServiceProxy.java:372
L3c_g$ @ RemoteServiceProxy.java:74
Dof_g$ @ StockPriceService_Proxy.java:32
Pnf_g$ @ ResponseFromServerPanel.java:157
Vnf_g$ @ ResponseFromServerPanel.java:68
vb_g$ @ Timer.java:135
(anonymous) @ Timer.java:139
xI_g$ @ Impl.java:309
AI_g$ @ Impl.java:368
(anonymous) @ Impl.java:78
ConsoleLogger.java:33 ERROR!!! com.google.gwt.user.client.rpc.StatusCodeException: 404 Not Found <html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>Error 404 Not Found</title>
</head>
<body><h2>HTTP ERROR 404</h2>
<p>Problem accessing /stockwatcher.StockWatcher/stockPrices. Reason:
<pre> Not Found</pre></p><hr><i><small>Powered by Jetty://</small></i><hr/>
</body>
</html>
"C:\Program Files\Java\jdk-11.0.10\bin\java.exe" -Dmaven.multiModuleProjectDirectory=C:\Users\user\Documents\Learn\GWT\StockWatcher "-Dmaven.home=C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.3.2\plugins\maven\lib\maven3" "-Dclassworlds.conf=C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.3.2\plugins\maven\lib\maven3\bin\m2.conf" "-Dmaven.ext.class.path=C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.3.2\plugins\maven\lib\maven-event-listener.jar" "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.3.2\lib\idea_rt.jar=61479:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.3.2\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.3.2\plugins\maven\lib\maven3\boot\plexus-classworlds-2.6.0.jar;C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.3.2\plugins\maven\lib\maven3\boot\plexus-classworlds.license" org.codehaus.classworlds.Launcher -Didea.version=2021.1.1 net.ltgt.gwt.maven:gwt-maven-plugin:1.0.0:devmode
[INFO] Scanning for projects...
[INFO]
[INFO] ---------------------< stockwatcher:StockWatcher >----------------------
[INFO] Building StockWatcher HEAD-SNAPSHOT
[INFO] ------------------------------[ gwt-app ]-------------------------------
[INFO]
[INFO] >>> gwt-maven-plugin:1.0.0:devmode (default-cli) > process-classes @ StockWatcher >>>
[INFO]
[INFO] --- gwt-maven-plugin:1.0.0:enforce-encoding (default-enforce-encoding) @ StockWatcher ---
[INFO]
[INFO] --- gwt-maven-plugin:1.0.0:add-super-sources (default-add-super-sources) @ StockWatcher ---
[INFO]
[INFO] --- gwt-maven-plugin:1.0.0:add-test-super-sources (default-add-test-super-sources) @ StockWatcher ---
[INFO]
[INFO] --- gwt-maven-plugin:1.0.0:generate-module (default-generate-module) @ StockWatcher ---
[INFO]
[INFO] --- maven-resources-plugin:3.0.2:resources (default-resources) @ StockWatcher ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory C:\Users\user\Documents\Learn\GWT\StockWatcher\src\main\resources
[INFO] skip non existing resourceDirectory C:\Users\user\Documents\Learn\GWT\StockWatcher\src\main\super
[INFO]
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ StockWatcher ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] <<< gwt-maven-plugin:1.0.0:devmode (default-cli) < process-classes @ StockWatcher <<<
[INFO]
[INFO]
[INFO] --- gwt-maven-plugin:1.0.0:devmode (default-cli) @ StockWatcher ---
[INFO] Super Dev Mode starting up
[INFO] workDir: C:\Users\user\Documents\Learn\GWT\StockWatcher\target\gwt\devmode\work
[WARNING] 2021-05-13 14:38:07.107:INFO::main: Logging initialized @1464ms
[INFO] Loading Java files in stockwatcher.StockWatcher.
[INFO] Module setup completed in 11059 ms
[WARNING] 2021-05-13 14:38:17.745:INFO:oejs.Server:main: jetty-9.2.14.v20151106
[WARNING] 2021-05-13 14:38:17.772:INFO:oejsh.ContextHandler:main: Started o.e.j.s.ServletContextHandler@419ae2fd{/,null,AVAILABLE}
[WARNING] 2021-05-13 14:38:17.810:INFO:oejs.ServerConnector:main: Started ServerConnector@4c64e6ee{HTTP/1.1}{
127.0.0.1:9876}
[WARNING] 2021-05-13 14:38:17.810:INFO:oejs.Server:main: Started @12163ms
[INFO]
[WARNING] 2021-05-13 14:38:17.906:INFO:oejs.Server:main: jetty-9.2.14.v20151106
[WARNING] 2021-05-13 14:38:18.062:INFO:oejsh.ContextHandler:main: Started c.g.g.d.s.j.WebAppContextWithReload@5af10{/,file:/C:/Users/user/Documents/Learn/GWT/StockWatcher/target/gwt/devmode/war/,AVAILABLE}{C:\Users\user\Documents\Learn\GWT\StockWatcher\target\gwt\devmode\war}
[WARNING] 2021-05-13 14:38:18.062:INFO:oejs.ServerConnector:main: Started ServerConnector@312ccd51{HTTP/1.1}{
127.0.0.1:8888}
[WARNING] 2021-05-13 14:38:18.062:INFO:oejs.Server:main: Started @12422ms
[INFO] GET /recompile/stockwatcher.StockWatcher
[INFO] Job stockwatcher.StockWatcher_1_0
[INFO] starting job: stockwatcher.StockWatcher_1_0
[INFO] binding: user.agent=safari
[INFO] Compiling module stockwatcher.StockWatcher
[INFO] Unification traversed 657 fields and methods and 282 types. 2 are considered part of the current module and 11 had all of their fields and methods traversed.
[INFO] Compiling 1 permutation
[INFO] Compiling permutation 0...
[INFO] Linking per-type JS with 2 new/changed types.
[INFO] Source Maps Enabled
[INFO] Compile of permutations succeeded
[INFO] Compilation succeeded -- 1.690s
[INFO] Linking into C:\Users\user\Documents\Learn\GWT\StockWatcher\target\gwt\devmode\work\stockwatcher.StockWatcher\compile-2\war\stockwatcher.StockWatcher; Writing extras to C:\Users\user\Documents\Learn\GWT\StockWatcher\target\gwt\devmode\work\stockwatcher.StockWatcher\compile-2\extras\stockwatcher.StockWatcher
[INFO] Link succeeded
[INFO] Linking succeeded -- 0.370s
[INFO] 2.607s total -- Compile completed
[INFO] GET /sourcemaps/stockwatcher.StockWatcher/3D0791663BC1DB0FD750DDEC8850522B_sourcemap.json
[INFO] sent source map for module 'stockwatcher.StockWatcher' in 51 ms
<module>
<inherits name="com.google.gwt.user.User"/>
<entry-point class="stockwatcher.client.StockWatcher"/>
<inherits name='com.google.gwt.user.theme.standard.Standard'/>
<!--<source path="client"/>-->
<!--<public path="public"/>-->
</module>