Convert groovy Closure to Java?

Question

EDIT: Why the down-votes? Been googling this at length, without success...

I have some groovy-classes, I'm trying to rewrite to Java.

The groovy-code uses wslite for REST-calls, and follows this pattern:

JsonBuilder request = createRequest();
Map<String, Object> params = createParams();
RESTClient client = new RESTClient(endpoint);
Response response = client.put(params) ( it -> { text(request); });

How do I rewrite the final line with the Closure part?

What is the Java equivalent?

Answer 1

Can't understand the goal because it's better to change rest-client if you are switching to java.

wslite library designed for groovy and using it for java will add complexity to your code.

---

However, in this particular case java code will look like this:

(it's groovy but with java-like syntax)

@Grab(group='com.github.groovy-wslite', module='groovy-wslite', version='1.1.2', transitive=false)

import groovy.json.*
import wslite.rest.*

@groovy.transform.CompileStatic
class TextBodyClosure extends Closure<Object> {
    Object body;
    public TextBodyClosure(Object owner, Object body) {
        super(owner);
        this.body = body;
    }
    public Object call() {
        ContentBuilder cb = (ContentBuilder)this.getDelegate();
        cb.text(body);
        return null;
    }
}

def content = ["hello": "world"];
JsonBuilder request = new JsonBuilder(content);
Map<String, Object> params = [:];
RESTClient client = new RESTClient("http://httpbin.org/put");
//Response response = client.put(params){ it -> text(request) };
Response response = client.put(params, new TextBodyClosure(this, request));

assert response.parsedResponseContent.json.json == content
println "SUCCESS"

this conversion based on a source code of wslite library.

when you are calling client.put(params, content) the following code executed to transform content-closure to bytes:

https://github.com/jwagenleitner/groovy-wslite/blob/master/src/main/groovy/wslite/rest/RESTClient.groovy#L101-L105

as you can see - the content-closure passed into ContentBuilder that executes closure against itself - so, the delegate object is ContentBuilder at moment of execution...

https://github.com/jwagenleitner/groovy-wslite/blob/master/src/main/groovy/wslite/rest/ContentBuilder.groovy#L45