I am working 2 different processes.
I am passing process name in JVM argument. Using that argument either of the processes should call.
my app context XML.
<bean id="propertyPlaceHolderConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath*:properties/${processJVMArg}.properties</value>
</list>
</property>
</bean>
<bean id="splitService" class="com.split.service.SplitService" init-method="process1"><!-- "based on processJVMArg JVM argument should call process1 or process2. " -->
Is there is a way to configure more than one init method, init method should call based on conduction?
Thanks,
Rama
Spring has profiles. Based on set of conditions you can start app with exact profile. Bean beanCreatingBasedOnProfile will be created only in dev profile.
#Bean
#Profile("dev")
public YourClass beanCreatingBasedOnProfile() {
return new YourClass();
}
Also spring has Conditional Beans .
You can construct bean based on property value or anything else. For example:
#ConditionalOnProperty(prefix = "spring.prop", name = "dynamic", matchIfMissing = true)
public YourClass condBean() {
return new YourClass();
}
Related
I am rewriting a legacy project using Quartz and Spring Framework. The original configuration is in XML and now I am translating it into Java Config. The xml configuration uses jobDetail to set the job detail property of the trigger bean. However, when I try to use the equivalent method, i.e. the setter: setJobDetails(simpleJobDetail), I got a warning that the setter does not have correct type (expecting JobDetails, but got MethodInvokingJobDetailFactoryBean).
May I know whether it is correct to translate xml bean configuration to Java COnfig by using the equivalent named setter in Java COnfig?
Why in the XML property setting, the trigger bean can set its jobDetail property as the simpleJobDetail bean (which has type MethodInvokingJobDetailFactoryBean) , while the Java Config could not?
XML config:
<!-- For times when you just need to invoke a method on a specific object -->
<bean id="simpleJobDetail"
class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
<property name="targetObject" ref="reader" />
<property name="targetMethod" value="readData" />
</bean>
<!-- Run the job every 60 seconds with initial delay of 1 second -->
<bean id="trigger"
class="org.springframework.scheduling.quartz.SimpleTriggerFactoryBean">
<property name="jobDetail" ref="simpleJobDetail" />
<property name="repeatInterval" value="600000" />
</bean>
Java Config:
#Bean
public MethodInvokingJobDetailFactoryBean simpleJobDetail() {
MethodInvokingJobDetailFactoryBean simpleJobDetail = new MethodInvokingJobDetailFactoryBean();
simpleJobDetail.setTargetObject(reader());
simpleJobDetail.setTargetMethod("readData");
return simpleJobDetail;
}
#Bean
private Object reader() {
// TODO: 10/13/2016
return null;
}
#Bean
public SimpleTriggerFactoryBean trigger() {
final SimpleTriggerFactoryBean trigger = new SimpleTriggerFactoryBean();
trigger.setJobDetail( simpleJobDetail()); // got warning about wrong type
trigger.setRepeatInterval(60000);
return trigger;
}
Note that simpleJobDetail() returns a factory, not the bean itself. You can rely on autowiring to inject a JobDetail built using this factory.
#Bean
public SimpleTriggerFactoryBean trigger(final JobDetail simpleJobDetail) {
final SimpleTriggerFactoryBean trigger = new SimpleTriggerFactoryBean();
trigger.setJobDetail(simpleJobDetail); // got warning about wrong type
trigger.setRepeatInterval(60000);
return trigger;
}
Hope it helps.
Java
public class MyObject{}
public class MyFactory{
private Optional<MyObject> myproperty;
public Optional<MyObject> getMyproperty{...}
public void setMyproperty{...}
}
Spring config xml (doesn't work)
<bean id="myproperty" class="java.util.Optional">
<constructor-arg>
<value>com.MyObject</value>
</constructor-arg>
</bean>
<bean id="myfactory" class="com.Myfactory">
<property name="myproperty" ref="myproperty" />
</bean>
Does spring support generics beans?
The reason for using Optional is it provide some useful features such as checking value if null. You can complete checking and further action in one line of code.
getMyproperty().ifPresent(id -> call.setId(id));
Seems the problem have nothing to do with generics.
You simply need to properly tell Spring to create the bean using a factory method, as Optional can only be created though factory methods. Something like:
<bean id="myproperty" class="java.util.Optional" factory-method="of">
<constructor-arg type="java.lang.Object" value="com.MyObject" />
</bean>
for which it is supposed to mean creating the myproperty bean by Optional.of(com.MyObject.class) (Change the factory-method to ofNullable if that's the one you want to use)
Another option is to use SpEL (Spring Expression Language):
<bean id="mybean" ...>
<property name="optProp" value="#{ T(java.util.Optional).of( #wrapme) }"/>
</bean>
Where "wrapme" is the name of a bean defined elsewhere that you want to wrap in java.util.Optional.
How can I configure the Apache CXF CrossOriginResourceSharingFilter without changing the source code (annotated class or beans.xml)?
In the JAX-RS: CORS example the configuration is hard-coded:
Here is the test code showing how CrossOriginResourceSharing annotations can be applied at the resource and individual method levels.
[...]
#GET
#CrossOriginResourceSharing(
allowOrigins = { "http://area51.mil:31415" },
allowCredentials = true,
exposeHeaders = { "X-custom-3", "X-custom-4" }
)
#Produces("text/plain")
#Path("/annotatedGet/{echo}")
public String annotatedGet(#PathParam("echo") String echo) {
return echo;
}
I use beans.xml to configure the allowOrigins property:
<bean id="cors-filter" class="org.apache.cxf.rs.security.cors.CrossOriginResourceSharingFilter">
<property name="allowOrigins">
<list>
<value>myserver1</value>
<value>myserver2</value>
</list>
</property>
</bean>
I thought I could get the property from JNDI, but it is not allowed to add a List (see Servlet Specification 2.5). And I need a way to configure an empty List for CORS *.
<bean id="cors-filter"
class="org.apache.cxf.rs.security.cors.CrossOriginResourceSharingFilter">
<property name="allowOrigins"><
<jee:jndi-lookup jndi-name="CORS/origins"/>
</property>
</bean>
What is the intended/preferred way to configure the CrossOriginResourceSharingFilter in a reusable WAR?
What if you use some environment variable to set a comma separated list of origins like this:
<bean id="cors-filter"
class="org.apache.cxf.rs.security.cors.CrossOriginResourceSharingFilter">
<property name="allowOrigins" value="#{systemProperties['origins'] != null ? systemProperties['origins'].split(',') : null}">
</property>
</bean>
this is a tested code
And pass -Dorigins=or1,or2,... to JVM (or don't pass to get null value)
If you need to pass an empty list in configuration you can edit code like this (replace null with {} in property value):
<bean id="cors-filter"
class="org.apache.cxf.rs.security.cors.CrossOriginResourceSharingFilter">
<property name="prop" value="#{systemProperties['test'] != null ? systemProperties['test'].split(',') : {}}">
</property>
</bean>
this way,if you don't add -Dorigins to Java VM Options, an empty list will be used.
Based on Spring EL Documentation you can use all object methods:
As an example of method invocation, we call the 'concat' method on the string literal.
Expression exp = parser.parseExpression("'Hello World'.concat('!')");
I am new to the Spring framework and can't find a way to achieve the following:
I am using a class whose attributes are all private and there are no setters (the intended way to use objects of that class is to set attributes once with a constructor) - I will refer to it as Preferences. I also have a few classes that each has the same instance of Preferences as an attribute. Preferences is intended to contain certain properties, among which some can only be resolved at runtime (e.g. provided by the user).
In my .xml file I would write something along the lines of:
<bean id="preferenes" class="Preferences" scope="singleton">
<constructor-arg index="0" value="defaultAttrOne" />
<constructor-arg index="1" value="defaultAttrTwo" />
<constructor-arg index="2" value="defaultAttrThree" />
</bean>
<bean id="someOtherBean" class="SomeOtherClass" scope="singleton">
<constructor-arg index="0" ref="preferences" />
</bean>
That is, I could provide default values and replace some of them with custom ones at runtime. As I cannot modify attributes of an existing instance of Preferences, I would have to construct a new object and somehow make the instance of SomeOtherClass point to that new object (is this possible through the bean mechanism?).
Rather, I'd pass the desired runtime constructor arguments to the preferences bean before instantiating any of the beans (those arguments will be known before the first call to the ApplicationContext's constructor). I know there is a flavour of the getBean() method that takes varargs as initialization parameters, though it only applies to prototype beans. In this case I want to initialize Preferenes once and have all helper classes refer to that single instance.
Thank you for any hints.
This is pretty much what Spring does for you by default so there is nothing special you'll have to do: if you create that singleton bean reference (called preferences), you'll be able to inject it to any other bean as you would expect.
Regarding your attributes with default values, there's several ways to achieve that:
Regular XML config
You can keep a purely XML-based configuration if you want and configure a PropertyPlaceholderConfigurer with default values. Something like:
<bean class="org.s.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location" value="prefrences.properties"/>
</bean>
<bean id="preferenes" class="Preferences" scope="singleton">
<constructor-arg index="0" value="$[preferences.one:12]" />
<constructor-arg index="1" value="$[preferences.two:AUTO]" />
<constructor-arg index="2" value="$[preferences.three:false]" />
</bean>
And have a prefrences.properties at the root of the classpath hold the specific values if you don't want the default
prefrences.three=true
FactoryBean
As you're already using XML, you can go with a FactoryBean that would create the Preferences instance, something like
<bean id="preferences" class="org.myproject.PreferencesFactoryBean"/>
in the code of the factory you could use whatever mechanism you want to retrieve the non default values for your configuration, including injecting custom properties.
Java config
You can also go the java config way but as you're a beginner this may be a bit of a change. However, java config is really powerful and flexible so you may want to give it a try.
#Configuration
#PropertySource("classpath:preferences.properties")
public class AppConfig {
#Value("${preferences.one}")
private int preferenceOne = 12;
#Value("${preferences.two}")
private MyEnum preferenceTwo = MyEnum.AUTO;
#Value("${preferences.three}")
private boolean preferenceThree;
#Bean
public static PropertySourcesPlaceholderConfigurer propertyPlaceholderConfigurer() {
return new PropertySourcesPlaceholderConfigurer();
}
#Bean
public Preferences preferences() {
return new Preferences(preferenceOne, preferenceTwo, preferenceThree);
}
}
I Am very new to Spring. I have an Interface (MessageHandler ) which has a get method, this method returns a list of Implementations of another interface (messageChecker).
public interface MessageHandler {
public void process(BufferedReader br);
public void setMessageCheckerList(List mcList);
[B]public List getMessageCheckerList();[/B]
}
In my Spring XML configuration , i have something like this ,along with other beans
<bean id="messageHandler" class="com.XXX.messagereceiver.MessageHandlerImpl">
<property name="messageCheckerList" ref="checkerList"/>
</bean>
<bean id="checkerList" class="java.util.ArrayList">
<constructor-arg>
<list>
<ref bean="HL7Checker"/>
</list>
</constructor-arg>
</bean>
<bean id="HL7Checker" class="com.XXX.messagereceiver.HL7CheckerImpl">
<property name="messageExecutor" ref="kahootzExecutor"/>
</bean>
Here i am passing a checkerlist - which is a list of Implementations ( For now i have only 1) of the Interface (messageChecker)
Checkerlist is containing references to Bean Id's which are actual implementaions.
HL7Checker is an implementation of an Interface messageChecker.
But when i run the main program, When i inject the bean "messageHandler" and call the getMessageCheckerList, It returns a null value. These getter and setter methods are working fine without using spring.
I am not sure what seems to be the problem.
I don't know the answer for you troubles, but I would check:
is the setter setMessageCheckerList(List) in messageHandler bean called? (either using some debugger or some trace output like System.out...). If it's not, there's probably something wrong with your Spring XML configuration setup. The bean definition you posted requires the property to be set and Spring wouldn't create the messageHandler bean without setting the property.
who calls the setMessageCheckerList(List) setter? Or even more precise, what code writes to the field which stores the value of the property? Maybe the field is initialized properly by Spring but gets overwritten to null later on?
are you sure you call the getMessageCheckerList on the very same object Spring has configured for you (that is, the messageHandler bean). The definition you have posted clearly states an instance of MessageHandlerImpl is created by Spring, but it doesn't prevent other instances to be created in other ways. So maybe the instance created by Spring holds the proper value, but you run the get... on a wrong instance?