问题
I have created restfull web application using spring boot web starter which works well. I am able to access it through urls.
But I have requirement to create console command which can compute and store some values at the backend. I want to be able to run console command manually or through bash script.
I could not find any documentation on how to integrate spring-shell project in spring boot web application.
Also there is no option to choose spring-shell dependency in spring boot starter https://start.spring.io/
1) Do webapp and console need to be two separate applications and I need to deploy them separately ?
2) Is it possible to deploy web app and run console commands in the same app ?
3) What is the best approach to share common code (model, services, entities, business logic) between shell and web applications ?
Can anyone please help on this ?
回答1:
Here's 2 options:
(1) Rest API called from the command line
You could create a Spring @RestController, which you then call from the command line ?
curl -X POST -i -H "Content-type: application/json" -c cookies.txt -X POST http://hostname:8080/service -d '
{
"field":"value",
"field2":"value2"
}
'
You can easily embed this in a nice shell script.
(2) Use spring-boot-remote-shell (deprecated)
Though it is mainly for monitoring/administration purposes, you may use the spring-boot-remote-shell for that.
Dependencies
You need the following dependencies to enable the remote-shell:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-remote-shell</artifactId>
</dependency>
<dependency>
<groupId>org.crsh</groupId>
<artifactId>crsh.shell.telnet</artifactId>
<version>1.3.0-beta2</version>
</dependency>
Groovy script:
Add the following script in src/main/resources/custom.groovy:
package commands
import org.crsh.cli.Command
import org.crsh.cli.Usage
import org.crsh.command.InvocationContext
class custom {
@Usage("Custom command")
@Command
def main(InvocationContext context) {
return "Hello"
}
}
To get a hold of a Spring bean from this groovy script (source: https://stackoverflow.com/a/24300534/641627):
BeanFactory beanFactory = (BeanFactory) context.getAttributes().get("spring.beanfactory");
MyController myController = beanFactory.getBean(MyController.class);
Launch your SpringBootApp
With spring-boot-remote-shell on the classpath, the Spring Boot Application listens on port 5000 (by default). You can now do this:
$ telnet localhost 5000
Trying ::1...
Connected to localhost.
Escape character is '^]'.
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.3.5.RELEASE)
Help
You can type help to see the list of available commands:
NAME DESCRIPTION
autoconfig Display auto configuration report from ApplicationContext
beans Display beans in ApplicationContext
cron manages the cron plugin
custom Custom command
dashboard
egrep search file(s) for lines that match a pattern
endpoint Invoke actuator endpoints
env display the term env
filter A filter for a stream of map
help provides basic help
java various java language commands
jmx Java Management Extensions
jul java.util.logging commands
jvm JVM informations
less opposite of more
log logging commands
mail interact with emails
man format and display the on-line manual pages
metrics Display metrics provided by Spring Boot
shell shell related command
sleep sleep for some time
sort Sort a map
system vm system properties commands
thread JVM thread commands
Call our custom command
Our custom command is listed (the fourth from the top), you can call it:
> custom
Hello
So, essentially, your crontab would do a telnet 5000 and execute custom
(3) How to use arguments and options (to answer question in comments)
Arguments
To use arguments, you can take a look at the documentation:
class date {
@Usage("show the current time")
@Command
Object main(
@Usage("the time format")
@Option(names=["f","format"])
String format) {
if (format == null)
format = "EEE MMM d HH:mm:ss z yyyy";
def date = new Date();
return date.format(format);
}
}
% date -h
% usage: date [-h | --help] [-f | --format]
% [-h | --help] command usage
% [-f | --format] the time format
% date -f yyyyMMdd
Sub-command (or options)
Still from their documentation:
@Usage("JDBC connection")
class jdbc {
@Usage("connect to database with a JDBC connection string")
@Command
public String connect(
@Usage("The username")
@Option(names=["u","username"])
String user,
@Usage("The password")
@Option(names=["p","password"])
String password,
@Usage("The extra properties")
@Option(names=["properties"])
Properties properties,
@Usage("The connection string")
@Argument
String connectionString) {
...
}
@Usage("close the current connection")
@Command
public String close() {
...
}
}
% jdbc connect jdbc:derby:memory:EmbeddedDB;create=true
The last command executes:
- the command
jdbc - with subcommand
connect - and the argument
jdbc:derby:memory:EmbeddedDB;create=true
A Complete example
The following contains:
- a constructor;
- a command with arguments;
- a spring managed bean;
- a subcommand with arguments.
The code:
package commands
import org.crsh.cli.Command
import org.crsh.cli.Usage
import org.crsh.command.InvocationContext
import org.springframework.beans.factory.BeanFactory
import com.alexbt.goodies.MyBean
class SayMessage {
String message;
SayMessage(){
this.message = "Hello";
}
@Usage("Default command")
@Command
def main(InvocationContext context, @Usage("A Parameter") @Option(names=["p","param"]) String param) {
BeanFactory beanFactory = (BeanFactory) context.getAttributes().get("spring.beanfactory");
MyBean bean = beanFactory.getBean(MyBean.class);
return message + " " + bean.getValue() + " " + param;
}
@Usage("Hi subcommand")
@Command
def hi(InvocationContext context, @Usage("A Parameter") @Option(names=["p","param"]) String param) {
BeanFactory beanFactory = (BeanFactory) context.getAttributes().get("spring.beanfactory");
MyBean bean = beanFactory.getBean(MyBean.class);
return "Hi " + bean.getValue() + " " + param;
}
}
> saymsg -p Johnny
> Hello my friend Johnny
> saymsg hi -p Johnny
> Hi my friend Johnny
回答2:
It sounds like you have two distinct use cases here: running scheduled tasks, and running commands manually. From my understanding, Spring Shell isn't part of the Boot ecosystem. You can write a Spring Shell application that is external to your Boot Web app, but it's not going to embed within it. At least from my experience.
For the first case of scheduled tasks, you should look at Spring's Scheduler. You should be able to configure a Spring application (Boot or normal) that has a Task Scheduler within it. Then you can configure your Tasks that can be scheduled, letting the scheduler do the work.
For manually executing the commands, you do have a few options here. If you use Spring Shell, assume it's running in its own process, external to the Spring Boot process. You would need to have the Shell app call into the Boot application (presuming that's where you want to work to occur) using remote method invocation technologies (eg, RMI, REST, etc).
An alternative to Spring Shell is to embed a remote shell into your Boot application. Essentially, you can use SSH to connect to your Boot application and define commands in a similar fashion as Spring Shell. The benefit is that this is in the same process as the Boot application. So you can inject the Task Scheduler and run the same Tasks manually as are scheduled. This might be a good option if you want to manually kick of the same Tasks are being scheduled. Doco for the remote console is here.
Hope this helps
来源：https://stackoverflow.com/questions/39329017/how-to-build-console-command-in-spring-boot-web-application-using-spring-shell