java - Spring MVC RestController scope -

-

i have following spring controller:

package hello;  import java.util.concurrent.atomic.atomiclong;  import org.springframework.web.bind.annotation.requestmapping; import org.springframework.web.bind.annotation.requestparam; import org.springframework.web.bind.annotation.restcontroller;  @restcontroller public class testcontroller {     private final atomiclong counter = new atomiclong();      @requestmapping("/test")     public string test() {         long val = counter.incrementandget();         return string.valueof(val);     } }

each time access rest api, returns incremented value. learning java , wondering why not return 1 new instance of atomiclong must have been created each time request comes.

no, testcontroller bean singleton. @restcontroller annotation declares spring @component scope default singleton. documented in @scope annotation:

defaults empty string ("") implies scope_singleton.

this means same instance of testcontroller handle every requests. since counter instance variable, same every request.


Comments

Post a Comment

Popular posts from this blog

javascript - Chart.js (Radar Chart) different scaleLineColor for each scaleLine -

-
Image
i try , create radar chart using chart.js has various colours each scaleline, or coloured between scalelines. wondering if possible? from: to: i have working graph, though there doesn't seem method change individual scale lines. kind regards leigh you can extend radar chart type this, so chart.types.radar.extend({ name: "radaralt", initialize: function (data) { chart.types.radar.prototype.initialize.apply(this, arguments); var originalscaledraw = this.scale.draw; var ctx = this.chart.ctx; this.scale.draw = function () { var linewidth = this.linewidth; // bypasses line drawing in originalscaledraw this.linewidth = linewidth; originalscaledraw.apply(this, arguments); ctx.linewidth = this.linewidth; var scale = this; // draw chart.helpers.each(scale.ylabels, function (label, index) { // color of ...
Read more

apache - Error with PHP mail(): Multiple or malformed newlines found in additional_header -

-
suddenly have started receiving above error without changes having been made script. host 1and1 (i know...) the script still works fine on different server, , suspicion there must have been server config change has lead this, although hosts plead ignorance. there's no information on above error @ in google can find - have ideas? server running apache if helps. had similar problem. came out of blue. no php code changed. what changed: php upgraded 5.5.25-1 5.5.26. a security risk in php mail() function has been fixed , newlines in additional_headers allowed no more. because newlines mean: starts email message (and surely don't want inject newlines through headers followed evil message). what have worked fine, e.g. having newlines after headers or passing whole message additional_headers , function no more. solution : sanitize headers. no multiple newlines in additional_headers argument. these count "multiple or malformed newlines":...
Read more

java - Android – MapFragment overlay button shadow, just like MyLocation button -

-
Image
i'm struggling add shadow custom overlay button on google map. goal make custom button google's mylocation button. here's how app looks now: layout.xml <relativelayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:map="http://schemas.android.com/apk/res-auto" android:layout_height="match_parent" android:layout_width="match_parent" style="@style/apptheme"> <fragment android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/map" tools:context=".mapsactivity" android:name="com.google.android.gms.maps.supportmapfragment" android:layout_alignparentend="true" android:layout_alignparentstart="true" android:layout_alignparentbottom="true" ...
Read more