How do i use a servlet in my grails app? - grails

I need to use some connectors which are actually servlets. How can I do this in Grails and what about the web.xml? How do I configure the url of the servlet?
I actually have a Spring application here and I am trying to convert it into a partial Grails app. I have a connector servlet in the spring-app, which I wish to use here but the mapping is a must to call the servlet in the gsp file. How can I do this? I basically need to know where the xml file is in case of Grails.

To get the web.xml file, you can run:
grails install-templates
Then, the file can be found in:
<yourapp>/src/templates/war/web.xml
Edit this as usual to add <servlet> and <servlet-mapping> sections, then put your servlet code in:
<yourapp>src/java/your/package/structure/WhateverServlet.java
and you should be good to go

If you are within a grails-plugin, then you have a defined place within your *GrailsPlugin.groovy, where to do such things. E.g. Look at the auto generated closure:
def doWithWebDescriptor = { xml ->
[]
}
In here you can add your custom servlet configurations:
def servlets = xml.'servlet'
servlets[servlets.size() - 1] + {
servlet {
'servlet-name'('yourName')
'servlet-class'('yourpackage.YourClass')
}
}
def mappings = xml.'servlet-mapping'
mappings[mappings.size() - 1] + {
'servlet-mapping' {
'servlet-name'('yourName')
'url-pattern'('/yourPattern/*')
}
}

good news and bad news, and I myself have asked this question here before. With spring application you can have multiple level of URI such as domain.com/abc/def/efg/abc vs grails has a lot of issue with anything beyond domain.com/controller/view. here is a link to my original question: Grails URL mapping cause error on GSP
The good news is, you don't need to deal with XML mapping, grails does it seemlessly by controllers and views. So you are almost limited to domain.com/YouController/YourView/SomeParamteres... but if thats all you'll need, all u have to do is create grails-app/Controller/SomethingController.groovy and you automatically have domain.com/Something

Related

What is the best way to modify a project configuration from within a plugin?

As I am trying to write a Grails Plugin, I stumbled upon two problems:
how do I modify one of the configuration files like Config.groovy or DataSource.groovy from witin the _install.groovy script? It is easy to append something to those files, but how do I modify it in a clean way? text.replaceAll()? Or should I create a new config file?
how do I get the name of the current application into which the plugin will be installed? I tried to use app.name and appName but both do not work.
Is there maybe somewhere a good tutorial on creating plugins which I haven't found yet?
Here is an example of editing configuration files from scripts/_Install.groovy.
My plugin copies three files to the target directory.
.hgignore is used for version control,
DataSource.groovy replaces the default version, and
SecurityConfig.groovy contains extra settings.
I prefer to edit the application's files as little as possible, especially because I expect to change the security setup a few years down the road. I also need to use properties from a jcc-server-config.properties file which is customized for each application server in our system.
Copying the files is easy.
println ('* copying .hgignore ')
ant.copy(file: "${pluginBasedir}/src/samples/.hgignore",
todir: "${basedir}")
println ('* copying SecurityConfig.groovy')
ant.copy(file: "${pluginBasedir}/src/samples/SecurityConfig.groovy",
todir: "${basedir}/grails-app/conf")
println ('* copying DataSource.groovy')
ant.copy(file: "${pluginBasedir}/src/samples/DataSource.groovy",
todir: "${basedir}/grails-app/conf")
The hard part is getting Grails to pick up the new configuration file. To do this, I have to edit the application's grails-app/conf/Config.groovy. I will add two configuration files to be found on the classpath.
println ('* Adding configuration files to grails.config.locations');
// Add configuration files to grails.config.locations.
def newConfigFiles = ["classpath:jcc-server-config.properties",
"classpath:SecurityConfig.groovy"]
// Get the application's Config.groovy file
def cfg = new File("${basedir}/grails-app/conf/Config.groovy");
def cfgText = cfg.text
def appendedText = new StringWriter()
appendedText.println ""
appendedText.println ("// Added by edu-sunyjcc-addons plugin");
// Slurp the configuration so we can look at grails.config.locations.
def config = new ConfigSlurper().parse(cfg.toURL());
// If it isn't defined, create it as a list.
if (config.grails.config.locations.getClass() == groovy.util.ConfigObject) {
appendedText.println('grails.config.locations = []');
} else {
// Don't add configuration files that are already on the list.
newConfigFiles = newConfigFiles.grep {
!config.grails.config.locations.contains(it)
};
}
// Add each surviving location to the list.
newConfigFiles.each {
// The name will have quotes around it...
appendedText.println "grails.config.locations << \"$it\"";
}
// Write the new configuration code to the end of Config.groovy.
cfg.append(appendedText.toString());
The only problem is adding SecurityConfig.groovy to the classpath. I found that you can do that by creating the following event in the plugin's /scripts/Events.groovy.
eventCompileEnd = {
ant.copy(todir:classesDirPath) {
fileset(file:"${basedir}/grails-app/conf/SecurityConfig.groovy")
}
}
Ed.
You might try changing the configuration within the MyNiftyPlugin.groovy file (assuming that your plugin is named my-nifty). I've found that I can change the configuration values within the doWithApplicationContext closure. Here's an example.
def doWithApplicationContext = { applicationContext ->
def config = application.config;
config.edu.mycollege.server.name = 'http://localhost:8080'
config.edu.mycollege.server.instance = 'pprd'
}
The values you enter here do show up in the grailsApplication.config variable at run time. If it works for you, it will be a neater solution, because it doesn't require changes to the client project.
I must qualify that with the fact that I wasn't able to get Spring Security to work by this technique. I believe that my plugin (which depends on Spring Security) was loaded after the security was initialized. I decided to add an extra file to the grails-app/conf directory.
HTH.
For modifying configuration files, you should use ConfigSlurper:
def configParser = new ConfigSlurper(grailsSettings.grailsEnv)
configParser.binding = [userHome: userHome]
def config = configParser.parse(new URL("file:./grails-app/conf/Config.groovy"))
If you need to get application name from script, try:
metadata.'app.name'

Grails External Config Read Incorrectly on First Load

Grails 1.3.7
I have some configuration located in an external config file. One of the entires looks like this:
site.maintenance.mode = false
I have a filter which checks for certain config settings for specific URLs. When I do a run-app or deploy a WAR into Tomcat and do:
boolean maintenanceMode = grailsApplication.config.site.maintenance.mode
maintenanceMode is coming back true. If I look at the config object in debug mode, this is what I get:
site={maintenance={mode=false, message="<p>Our trail guides are working hard to get the system back on track.</p><p>We're sorry, the account system is down for maintenance at the moment. We'll get it back online as quickly as we can. Thanks for your patience.</p>"}}
I have a controller that I use to reload this config file dynamically and hitting this controller will fix the issue. But I'm curious as to why it is incorrect on first runs and why the discrepency in what is getting put in the maintenanceMode variable vs what is actually in the config object.
Are you using a Java properties file or a Groovy file? If you're using a properties file then I believe Grails will interpret site.maintenance.mode=false the same way as site.maintenance.mode='false' and since Groovy will interpret:
"false".asBoolean() == true
then that would explain why you would see that initial true value.
I just ran a simple test locally to verify this behavior. When I externalize my properties in a file called test.properties then site.maintenance.mode=false initially gets a boolean value of true, when I use a file called test.groovy then it interprets the boolean value of site.maintenance.mode=false as false. I believe this is because when you use a Groovy file Grails uses ConfigurationSlurper to process it but when you use a properties file Grails interprets everything as String name/value pairs.
What I do is to have an external Config.groovy file, for instance: MyConfig.groovy
At the end of the standard grails Config.groovy file, I have the following:
def ENV_NAME = "MY_EXTERNAL_CONFIG"
if(!grails.config.locations || !(grails.config.locations instanceof List)) {
grails.config.locations = []
}
if(System.getenv(ENV_NAME)) {
grails.config.locations << "file:" + System.getenv(ENV_NAME)
} else if(System.getProperty(ENV_NAME)) {
grails.config.locations << "file:" + System.getProperty(ENV_NAME)
} else {
println "No external Configs found."
}
So now you can have a MyConfig.groovy file anywhere in production environment (for example) and then set an Environment system variable to point to this file (or pass it as parameter to startup.sh), before you start tomcat:
MY_EXTERNAL_CONFIG="/home/tomcat/configs/MyConfig.groovy"
export MY_EXTERNAL_CONFIG
That's it. Now you have an external MyConfig.groovy file. The properties in it are accessible from your grails app as they were part of the standard Config.groovy
import org.codehaus.groovy.grails.commons.*
//...
ConfigurationHolder.config.foo.bar.hello

Is it possible to load more config files from an externalized config file in Grails?

Hypothetical situation:
I have downloaded a Grails application from the web as a WAR file, foo.war. In the documentation it says that I can put my own custom configuration in /foo.groovy, because this path is included in grails.config.locations in Config.groovy. I can dump all my custom config in that one file and life is good.
How, here's my problem... The configuration for FooApp is big and hairy, and I don't want it all in one file. I would like to break it up into /bar.groovy and /baz.groovy to keep things organized. Is there a way to specify something in /foo.groovy so that FooApp will also pick up /bar.groovy and /baz.groovy and process them?
I already tried appending paths to grails.config.locations in /foo.groovy, but Grails didn't like that and threw a nasty exception on startup. I'm not sure what other approach to take.
Edit for clarity:
grails-app/conf/Config.groovy looks like this:
grails.config.locations = ["file:/foo.groovy"]
Now, without modifying grails-app/conf/Config.groovy, and only by modifying /foo.groovy, is there a way to load more config files other than /foo.groovy?
You could slurp the additional config files within foo.groovy:
foo.groovy
port {
to {
somewhere=8080
another {
place=7070
}
}
}
host = new ConfigSlurper().parse(new File("bar.groovy").toURL())
bar.groovy
to {
somewhere="http://localhost/"
another {
place="https://another.place.com/"
}
}
So within your app you have:
assert grailsApplication.config.port.to.somewhere == 8080
assert grailsApplication.config.port.to.another.place == 7070
assert grailsApplication.config.host.to.somewhere == "http://localhost/"
assert grailsApplication.config.host.to.another.place == "https://another.place.com/"

Grails support for consuming web services

Does Grails provide built-in or via a plugin support to consume (not to generate) XML based REST or SOAP web services ( esp. REST) ?
http://www.grails.org/plugin/rest
For SOAP based webservices, use WSClient. The plugin is a wrapper around GroovyWS. Under the hood, Apache CXF is working there.
In the past, I created a script (grails create-script) that used wsimport to create POJOs in the java src directory. Each time the script ran, it would delete the generated directory if it existed first, then generate new files.
I did this because the API that was being consumed was being developed and I wanted an easy way to consume the latest and greatest when new functionality was added.
In grails 3.x you can use the plugin in build.gradle
compile 'com.github.groovy-wslite:groovy-wslite:1.1.2'
Then add the import to your controller like in http://guides.grails.org/grails-soap/guide/index.html
import wslite.soap.*
import wslite.soap.SOAPClient
import wslite.soap.SOAPResponse
and use as the example available in https://github.com/jwagenleitner/groovy-wslite
def client = new SOAPClient('http://www.holidaywebservice.com/Holidays/US/Dates/USHolidayDates.asmx')
def response = client.send(SOAPAction:'http://www.27seconds.com/Holidays/US/Dates/GetMothersDay') {
body {
GetMothersDay('xmlns':'http://www.27seconds.com/Holidays/US/Dates/') {
year(2011)
}
}
}
assert "2011-05-08T00:00:00" == response.GetMothersDayResponse.GetMothersDayResult.text()
assert 200 == response.httpResponse.statusCode
assert "ASP.NET" == response.httpResponse.headers['X-Powered-By']
render (response.GetMothersDayResponse.GetMothersDayResult.text())

Errors with SSL validation in Grails

I want to make a post to an url with SSL validation in Grails.
I've imported the certificates, and I've generated the jks files.
But it seems Grails does not found those jks files.
Below is the code I'm executing (it's in a Grails Service Class):
def certificate = "mycert.jks"
def http = new HTTPBuilder(url)
def keyStore = KeyStore.getInstance(KeyStore.defaultType)
getClass().getResource(certificate).withInputStream {
keyStore.load(it, "test1234".toCharArray())
}
http.client.connectionManager.schemeRegistry.register(new Scheme("https", new SSLSocketFactory(keyStore), 443))
The error is
"Cannot invoke method withInputStream() on null object"
so
the method getResource() is not working, and returns null.
I saw that this code, in a functionalTest Class, works fine.
Anyone knows how can I solve this problem?
Thanks!!!!!!!
The problem is that non-source files from grails-app/services aren't copied into the classpath. This is the case for src/java though, but not src/groovy. It's also the case for grails-app/conf, but that's the only grails-app folder that this happens for, since it's the configuration file folder.
So your best bet is to move the file to grails-app/conf and use
Thread.currentThread().contextClassLoader.getResource(certificate).withInputStream {
keyStore.load(it, "test1234".toCharArray())
}

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