java - Yet Another ApplicationContext is Null -
i'm having trouble autowiring spring bean in application. i've done before in other applications success, reason i'm getting stumped. i've googled around, , have found many folks having same troubles, , warnings go along using getapplicationcontext() approach no answers helped me. understand warnings , still have case want way, maybe i'll working using aspectj , compile time weaving.
here setup:
applicationcontext.xml
<?xml version="1.0" encoding="utf-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/xmlschema-instance" xmlns:oxm="http://www.springframework.org/schema/oxm" xmlns:util="http://www.springframework.org/schema/util" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xsi:schemalocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/oxm http://www.springframework.org/schema/oxm/spring-oxm-3.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd"> <context:property-placeholder location="classpath:widgetclient.properties"/> <context:component-scan base-package="com.mycompany.widget.domain" /> <context:component-scan base-package="com.mycompany.widget.services" /> <context:annotation-config /> <bean id="messagesource" class="org.springframework.context.support.resourcebundlemessagesource"> <property name="basename" value="messages" /> </bean> <bean id="heartbeat" class="com.company.widget.domain.checkwidgetserverheartbeat" destroy-method="destroy"> <constructor-arg type="java.lang.integer" name="interval" value="${heartbeat.interval}"/> <constructor-arg type="java.lang.integer" name="timeout" value="${heartbeat.timeout}"/> <constructor-arg type="java.lang.integer" name="unhealthythreshold" value="${unhealthy.threshold}"/> <constructor-arg type="java.lang.integer" name="healthythreshold" value="${healthy.threshold}"/> <constructor-arg type="java.lang.integer" name="backupverifytime" value="${backup.verify.time}"/> <constructor-arg type="java.lang.string" name="apiserverurl" value="${api.server.url}" /> </bean> </beans> baseservice.java
package com.company.widget.services; import com.company.widget.domain.checkwidgetserverheartbeat; import org.springframework.beans.factory.annotation.autowired; import org.springframework.context.applicationcontext; import org.springframework.stereotype.component; @component public class baseservice{ @autowired private applicationcontext appcontext; public baseservice(){} public checkwidgetserverheartbeat getheartbeat(){ return (checkwidgetserverheartbeat) appcontext.getbean("heartbeat"); } } heartbeatservice.java
package com.company.widget.services; import org.springframework.stereotype.service; import org.apache.log4j.logger; @service public class heartbeatservice extends baseservice{ private static final logger logger = logger.getlogger(heartbeatservice.class); public heartbeatservice(){} public boolean ishealthy(){ return getheartbeat().check(); } } companywidgetclient.java
package com.company.widget.domain; import javax.servlet.http.httpservletrequest; import java.io.*; import java.util.locale; import java.util.resourcebundle; import java.net.httpurlconnection; import java.net.inetaddress; import java.net.uri; import java.net.url; import java.net.urlconnection; import java.net.unknownhostexception; import java.util.*; import com.company.widget.services.heartbeatservice; import org.apache.log4j.logger; import org.springframework.beans.factory.annotation.autowired; import org.springframework.context.applicationcontext; import org.springframework.stereotype.component; @component public class companywidgetclient{ @autowired private heartbeatservice heartbeatservice; public companywidgetclient(string settingsxmlfilepath, httpservletrequest request){ if(settingsxmlfilepath != null){ configuration = new companywidgetconfiguration(settingsxmlfilepath, request); } if(request != null){ this.request = request; } //use api server url settings file if present if (configuration.getproperty("api_server_url") != null) { this.apiserverurl = configuration.getproperty("api_server_url"); log.debug("set api_server_url " + this.apiserverurl + " found in settings.xml"); } } public companywidgetclient(companywidgetconfiguration configuration, httpservletrequest request){ if(configuration != null){ this.configuration=configuration; } if(request != null){ this.request = request; } //use api server url settings file if present if (configuration.getproperty("api_server_url") != null) { this.apiserverurl = configuration.getproperty("api_server_url"); log.debug("set api_server_url " + this.apiserverurl + " found in settings.xml"); } } public companywidgetclient(){} private companywidgetresponse requestwidget(){ if(heartbeatservice.ishealthy()){ stuff... } index.jsp
<%@ page import="com.company.widget.domain.*" %> <%@ page contenttype="text/html;charset=utf-8" language="java" %> <% companywidgetclient widgetclient = new companywidgetclient("/web-inf/settings.xml", request); string companywidgetcomponent = widgetclient.createwidget(); %> ... html stuff ... <div id="widget"> <%=companywidgetcomponent%> </div> ... the error:
500 org.apache.jasper.jasperexception: exception occurred processing jsp page /index.jsp @ line 5 2: <%@ page contenttype="text/html;charset=utf-8" language="java" %> 3: <% 4: companywidgetclient widgetclient = new companywidgetclient("/web-inf/settings.xml", request); 5: string companywidgetcomponent = widgetclient.createwidget(); 6: %> 7: <!doctype html public "-//w3c//dtd xhtml 1.0 strict//en" 8: "http://www.w3.org/tr/xhtml1/dtd/xhtml1-strict.dtd"> stacktrace: org.apache.jasper.servlet.jspservletwrapper.handlejspexception(jspservletwrapper.java:568) org.apache.jasper.servlet.jspservletwrapper.service(jspservletwrapper.java:470) org.apache.jasper.servlet.jspservlet.servicejspfile(jspservlet.java:390) org.apache.jasper.servlet.jspservlet.service(jspservlet.java:334) javax.servlet.http.httpservlet.service(httpservlet.java:722) root cause java.lang.nullpointerexception com.company.widget.domain.companywidgetclient.requestwidget(companywidgetclient.java:553) com.company.widget.domain.companywidgetclient.createwidget(companywidgetclient.java:603) org.apache.jsp.index_jsp._jspservice(index_jsp.java:67) org.apache.jasper.runtime.httpjspbase.service(httpjspbase.java:70) javax.servlet.http.httpservlet.service(httpservlet.java:722) org.apache.jasper.servlet.jspservletwrapper.service(jspservletwrapper.java:432) org.apache.jasper.servlet.jspservlet.servicejspfile(jspservlet.java:390) org.apache.jasper.servlet.jspservlet.service(jspservlet.java:334) javax.servlet.http.httpservlet.service(httpservlet.java:722) observations:
i know i'm missing required default constructor present on companyclient object, , logs builds companyclient object on deployment. guess i'm not clear on scope when comes spring application context. understanding singleton bean should available using application context irrespective of scope of calling bean. , appreciated!
when instantiating companywidgetclient directly:
new companywidgetclient(...) you not giving spring di container chance inject instance of heartbeatservice - null.
when getting instance of companywidgetclient - retrieve instance spring applicaiton context (via getbean() or similar) - heartbeatservice have been autowired.
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