java - 理解java中的一些groovy代码

Question

出于某种原因，我需要将groovy代码重写为java。如果重要的话，它是 gradle 插件。但我不明白一些代码。您能一步步解释一下吗？可能用java代码吗？

class DeployPlugin implements Plugin<Project> {
    @Override
    void apply(Project project) {
        project.with {
            apply plugin: 'org.hidetake.ssh'
            ssh.settings {
                identity = file(ssh_file)
                knownHosts = allowAnyHosts
                passphrase = ssh_passphrase
            }
    ...

据我了解 project.with{ } 意味着内部的方法(哪个？)被 project 实例调用。

apply plugin: 'org.hidetake.ssh' - 可以用 project.getPlugins() .apply("org.hidetake.ssh") 表示吗？

ssh.settings - 这里的ssh是什么？如果它是一个变量，我怎样才能在java中获取它的实例？

ssh.settings {someExpressions} - 在此上下文中花括号的用途是什么？

Answer 1

Java 中的代码可能如下所示:

public class DeployPlugin implements Plugin<Project> {
    @Override
    public void apply(Project project) {
        project.getPlugins().apply("org.hidetake.ssh");
        org.hidetake.groovy.ssh.core.Service ssh = project.getExtensions().getByType(org.hidetake.groovy.ssh.core.Service.class);
        ssh.settings(new MethodClosure(this, "configureSettingsClosure"));
    }

    private void configureSettingsClosure(org.hidetake.groovy.ssh.core.settings.GlobalSettings settings) {
        settings.setIdentity(ssh_file);
        settings.setKnownHosts(settings.getAllowAnyHosts());
        settings.setPassphrase("p@ssw0rd");
    }

或者如果你不想依赖 groovy-ssh 可能是这样的，但我不推荐它:

public class DeployPlugin implements Plugin<Project> {
    @Override
    public void apply(Project project) {
        project.getPlugins().apply("org.hidetake.ssh");
        Object ssh = project.getExtensions().getByName("ssh");
        try {
            Method settings = ssh.getClass().getDeclaredMethod("settings", Closure.class);
            settings.invoke(ssh, new MethodClosure(this, "configureSettingsClosure"));
        } catch (IllegalAccessException | NoSuchMethodException e) {
            throw new AssertionError("Should not happen except by using a different groovy-ssh version that changed incompatibly", e);
        } catch (InvocationTargetException e) {
            throw new RuntimeException(e);
        }
    }

    private void configureSettingsClosure(Object settings) throws InvocationTargetException {
        try {
            Method setIdentity = settings.getClass().getDeclaredMethod("setIdentity", Object.class);
            setIdentity.invoke(settings, ssh_file);
            Method getAllowAnyHosts = settings.getClass().getDeclaredMethod("getAllowAnyHosts");
            Method setKnownHosts = settings.getClass().getDeclaredMethod("setKnownHosts", File.class);
            setKnownHosts.invoke(settings, getAllowAnyHosts.invoke(settings));
            Method setPassphrase = settings.getClass().getDeclaredMethod("setPassphrase", String.class);
            setPassphrase.invoke(settings, "p@ssw0rd");
        } catch (NoSuchMethodException | IllegalAccessException e) {
            throw new AssertionError("Should not happen except by using a different groovy-ssh version that changed incompatibly", e);
        }
    }