com.google.inject.spi.DefaultElementVisitor#com.google.inject.spi.Element源码实例Demo

@Override
public Void visit(ExposedBinding<? extends T> binding) {
    final PrivateBinder privateBinder = this.binder.newPrivateBinder();
    final Scoper scoper = new Scoper(privateBinder, scoping);
    for(Element element : binding.getPrivateElements().getElements()) {
        if(element instanceof Binding) {
            ((Binding) element).acceptTargetVisitor(scoper);
        } else {
            element.applyTo(privateBinder);
        }
    }
    for(Key key : binding.getPrivateElements().getExposedKeys()) {
        privateBinder.expose(key);
    }
    return null;
}
 

/**
 * Parse single guice element.
 *
 * @param injector injector instance
 * @param element  element to analyze
 * @return parsed descriptor or null if element is not supported (or intentionally skipped)
 */
public static BindingDeclaration parseElement(final Injector injector, final Element element) {
    final BindingDeclaration dec = element.acceptVisitor(ELEMENT_VISITOR);

    if (dec != null) {
        fillDeclaration(dec, injector);
        fillSource(dec, element);
        dec.setModule(BindingUtils.getModules(element).get(0));

        if (dec.getKey() != null) {
            final Class ann = dec.getKey().getAnnotationType();
            if (ann != null) {
                if (ann.getName().equals("com.google.inject.internal.Element")) {
                    dec.setSpecial(Collections.singletonList("multibinding"));
                }
                if (ann.getName().startsWith("com.google.inject.internal.RealOptionalBinder")) {
                    dec.setSpecial(Collections.singletonList("optional binding"));
                }
            }
        }
    }

    return dec;
}
 

private static Map<String, ModuleDeclaration> indexElements(final Injector injector,
                                                            final Collection<? extends Element> elements) {
    final Map<String, ModuleDeclaration> index = new LinkedHashMap<>();
    for (Element element : elements) {
        try {
            final BindingDeclaration dec = parseElement(injector, element);
            if (dec == null) {
                continue;
            }
            // create modules for entire modules chains
            final ModuleDeclaration mod = initModules(index, BindingUtils.getModules(element));
            mod.getDeclarations().add(dec);
        } catch (PrivateModuleException ex) {
            // private module appeared
            indexPrivate(index, injector, ex.getElements());
        }
    }
    return index;
}
 

private void renderGuiceWeb(final TreeNode filter) throws Exception {
    final List<String> servlets = new ArrayList<>();
    final List<String> filters = new ArrayList<>();

    for (Element element : Elements.getElements(Stage.TOOL, modules)) {
        if (!(element instanceof Binding)) {
            continue;
        }
        @SuppressWarnings("unchecked") final WebElementModel model =
                (WebElementModel) ((Binding) element).acceptTargetVisitor(VISITOR);
        if (model == null) {
            continue;
        }
        final String line = renderGuiceWebElement(model, element);
        if (model.getType().equals(WebElementType.FILTER)) {
            filters.add(line);
        } else {
            servlets.add(line);
        }
    }
    renderGucieWebElements(servlets, filters, filter);
}
 

private static boolean isInDisabledModule(final Element element,
                                          final List<String> disabled,
                                          final Set<String> actuallyDisabled) {
    if (!disabled.isEmpty()) {
        final List<String> modules = BindingUtils.getModules(element);
        // need to check from top modules to lower, otherwise removed modules list will be incorrect
        for (int i = modules.size() - 1; i >= 0; i--) {
            final String mod = modules.get(i);
            if (disabled.contains(mod)) {
                actuallyDisabled.add(mod);
                return true;
            }
        }
    }
    return false;
}
 

/**
 * Resolve guice configuration element declaration module chain. The first list element is declaration module.
 * Later elements appear if module was installed by other module.
 *
 * @param element guice SPI element
 * @return modules chain from declaration point or single {@link #JIT_MODULE} if binding is a JIT binding
 */
public static List<String> getModules(final Element element) {
    final List<String> modules;
    if (element.getSource() instanceof ElementSource) {
        ElementSource source = (ElementSource) element.getSource();
        // if module was repackaged by elements api, we need an original source in order to build correct report
        if (source.getOriginalElementSource() != null) {
            source = source.getOriginalElementSource();
        }
        modules = source.getModuleClassNames();
    } else {
        // consider JIT binding
        modules = Collections.singletonList(JIT_MODULE);
    }
    return modules;
}
 

@Override
protected void configure() {
    for (Element element : privateElements.getElements()) {
        if (element instanceof Binding && isExcluded(((Binding<?>) element).getKey())) {
            continue;
        }
        element.applyTo(binder());
    }

    for (Key<?> exposedKey : privateElements.getExposedKeys()) {
        if (isExcluded(exposedKey)) {
            continue;
        }
        expose(exposedKey);
    }
}
 

default void installIn(Scoping scoping, Module... modules) {
    final Scoper scoper = new Scoper(this, scoping);
    for(Element element : Elements.getElements(modules)) {
        if(element instanceof Binding) {
            ((Binding) element).acceptTargetVisitor(scoper);
        } else {
            element.applyTo(this);
        }
    }
}
 

public DependencyCollector processElements(Iterable<Element> elements) {
    final ElementVisitor visitor = new ElementVisitor();
    for(Element element : elements) {
        element.acceptVisitor(visitor);
    }
    processImplicitBindings();
    return this;
}
 

public static <T> Optional<Binding<T>> findBinding(Iterable<? extends Element> elements, Key<T> key) {
    for(Element element : elements) {
        if(element instanceof Binding && key.equals(((Binding<?>) element).getKey())) {
            return Optional.of((Binding<T>) element);
        }
    }
    return Optional.empty();
}
 

private Module createModule() {
    List<Element> allElements = new LinkedList<>();
    for (List<Element> moduleElements : modules.values()) {
        allElements.addAll(moduleElements);
    }
    ElementCollector collector = new ElementCollector();
    for (ListIterator<Element> it = allElements.listIterator(allElements.size()); it.hasPrevious(); ) {
        it.previous().acceptVisitor(collector);
    }
    return Elements.getModule(collector.elements);
}
 

public void assertAllDependenciesDeclared() {
  List<Key> requiredKeys = new ArrayList<>();

  List<Element> elements = Elements.getElements(module);
  for (Element element : elements) {
    element.acceptVisitor(new DefaultElementVisitor<Void>() {
      @Override
      public <T> Void visit(ProviderLookup<T> providerLookup) {
        // Required keys are the only ones with null injection points.
        if (providerLookup.getDependency().getInjectionPoint() == null) {
          requiredKeys.add(providerLookup.getKey());
        }
        return null;
      }
    });
  }

  Injector injector = Guice.createInjector(module,
      new AbstractModule() {
        @Override
        @SuppressWarnings("unchecked")
        protected void configure() {
          binder().disableCircularProxies();
          binder().requireAtInjectOnConstructors();
          binder().requireExactBindingAnnotations();

          for (Key<?> key : requiredKeys) {
            bind((Key) key).toProvider(Providers.of(null));
          }
        }
      });

  injector.getAllBindings();
}
 

@Override
public String renderReport(final GuiceAopConfig config) {
    final StringBuilder res = new StringBuilder();

    // AOP declarations
    final List<Element> declared = Elements.getElements(Stage.TOOL, modules).stream()
            .filter(it -> it instanceof InterceptorBinding)
            .collect(Collectors.toList());

    if (!config.isHideDeclarationsBlock()) {
        final List<ModuleDeclaration> declarationModules = GuiceModelParser.parse(injector, declared);
        res.append(Reporter.NEWLINE).append(Reporter.NEWLINE);
        renderDeclared(declarationModules, res);
    }

    if (!declared.isEmpty()) {
        // AOP appliance map
        final List<Binding> guiceManagedObjects = injector.getAllBindings().values().stream()
                .filter(it -> it instanceof ConstructorBinding)
                .collect(Collectors.toList());
        final List<AopDeclaration> tree = filter(GuiceModelParser.parse(injector, guiceManagedObjects), config);
        if (!tree.isEmpty()) {
            res.append(Reporter.NEWLINE).append(Reporter.NEWLINE);
            renderMap(tree, res);
        }
    }
    return res.toString();
}
 

/**
 * NOTE: this will work only for elements, parsed with SPI api, and not for real bindings!
 *
 * @param element guice binding element
 * @return element declaration stacktrace element
 */
public static StackTraceElement getDeclarationSource(final Element element) {
    final Object source = element.getSource();
    StackTraceElement traceElement = null;
    if (source instanceof ElementSource) {
        final ElementSource src = (ElementSource) source;
        if (src.getDeclaringSource() instanceof StackTraceElement) {
            traceElement = (StackTraceElement) src.getDeclaringSource();
        } else if (src.getDeclaringSource() instanceof Method) {
            traceElement = (StackTraceElement) StackTraceElements.forMember((Method) src.getDeclaringSource());
        }
    }
    return traceElement;
}
 

/**
 * Parse guice elements into modules tree. Only direct bindings are accepted. Supports both module elements
 * and injector bindings (but result will slightly vary). JIT bindings are also grouped into special module.
 *
 * @param injector injector instance
 * @param elements elements to analyze
 * @return tree of modules.
 */
public static List<ModuleDeclaration> parse(final Injector injector,
                                            final Collection<? extends Element> elements) {
    final Map<String, ModuleDeclaration> index = indexElements(injector, elements);
    final List<ModuleDeclaration> res = new ArrayList<>();

    // build modules tree
    for (ModuleDeclaration mod : index.values()) {
        if (mod.getParent() != null) {
            index.get(mod.getParent()).getChildren().add(mod);
        } else {
            res.add(mod);
        }
        // sort declarations according to declaration order (in module)
        mod.getDeclarations().sort(Comparator
                .comparingInt(BindingDeclaration::getSourceLine)
                .thenComparing(BindingDeclaration::getType)
                .thenComparing(it -> it.getScope() != null ? it.getScope().getSimpleName() : "")
                .thenComparing(it -> it.getKey() != null ? GuiceModelUtils.renderKey(it.getKey()) : ""));
    }

    // sort entire tree by module name for predictable order
    final Comparator<ModuleDeclaration> moduleComparator = Comparator.comparing(ModuleDeclaration::isJitModule)
            .thenComparing(it -> it.getType().getName());
    res.sort(moduleComparator);
    GuiceModelUtils.visit(res, it -> it.getChildren().sort(moduleComparator));

    // return only root modules
    return res;
}
 

private static void fillSource(final BindingDeclaration dec, final Element element) {
    final StackTraceElement trace = GuiceModelUtils.getDeclarationSource(element);
    if (trace != null) {
        // using full stacktrace element to grant proper link highlight in idea
        dec.setSource(trace.toString());
        dec.setSourceLine(trace.getLineNumber());
    } else {
        final Object source = element.getSource();
        if (source instanceof Class) {
            dec.setSource(((Class) source).getName());
        } else {
            LOGGER.warn("Unknown element '{}' source: {}", dec, source);
        }
    }
}
 

private String renderGuiceWebElement(final WebElementModel model, final Element element) throws Exception {
    return String.format("%-15s %-20s %-7s %-30s %s",
            model.getType().equals(WebElementType.FILTER) ? "guicefilter" : "guiceservlet",
            model.getPattern(),
            model.getPatternType() == UriPatternType.REGEX ? "regex" : "",
            (model.isInstance() ? "instance of " : "") + GuiceModelUtils.renderKey(model.getKey()),
            RenderUtils.renderClass(Class.forName(BindingUtils.getModules(element).get(0))));
}
 

/**
 * Search for extensions in guice bindings (directly declared in modules).
 * Only user provided modules are analyzed. Overriding modules are not analyzed.
 * <p>
 * Use guice SPI. In order to avoid duplicate analysis in injector creation time, wrap
 * parsed elements as new module (and use it instead of original modules). Also, if
 * bound extension is disabled, target binding is simply removed (in order to
 * provide the same disable semantic as with usual extensions).
 *
 * @param context configuration context
 * @return list of repackaged modules to use
 */
private static List<Module> analyzeModules(final ConfigurationContext context,
                                           final Stopwatch modulesTimer) {
    List<Module> modules = context.getNormalModules();
    final Boolean configureFromGuice = context.option(AnalyzeGuiceModules);
    // one module mean no user modules registered
    if (modules.size() > 1 && configureFromGuice) {
        // analyzing only user bindings (excluding overrides and guicey technical bindings)
        final GuiceBootstrapModule bootstrap = (GuiceBootstrapModule) modules.remove(modules.size() - 1);
        try {
            // find extensions and remove bindings if required (disabled extensions)
            final Stopwatch gtime = context.stat().timer(Stat.BindingsResolutionTime);
            final List<Element> elements = new ArrayList<>(
                    Elements.getElements(context.option(InjectorStage), modules));
            gtime.stop();

            // exclude analysis time from modules processing time (it's installer time)
            modulesTimer.stop();
            analyzeAndFilterBindings(context, modules, elements);
            modulesTimer.start();

            // wrap raw elements into module to avoid duplicate work on guice startup and put back bootstrap
            modules = Arrays.asList(Elements.getModule(elements), bootstrap);
        } catch (Exception ex) {
            // better show meaningful message then just fail entire startup with ambiguous message
            // NOTE if guice configuration is not OK it will fail here too, but user will see injector creation
            // error as last error in logs.
            LOGGER.error("Failed to analyze guice bindings - skipping this step. Note that configuration"
                    + " from bindings may be switched off with " + GuiceyOptions.class.getSimpleName() + "."
                    + AnalyzeGuiceModules.name() + " option.", ex);
            // recover and use original modules
            modules.add(bootstrap);
            if (!modulesTimer.isRunning()) {
                modulesTimer.start();
            }
        }
    }
    return modules;
}
 

protected V message(Element element, String text) {
    return message(element.getSource(), text);
}
 

public static List<Element> visit(ElementVisitor<?> visitor, Iterable<? extends Module> modules) {
    final List<Element> elements = Elements.getElements(Stage.TOOL, modules);
    elements.forEach(e -> e.acceptVisitor(visitor));
    return elements;
}
 

public static List<Element> visit(ElementVisitor<?> visitor, Module... modules) {
    return visit(visitor, Arrays.asList(modules));
}
 

@Override
public Boolean visitOther(Element element) {
    elements.add(element);
    return Boolean.TRUE;
}
 

/**
 * May return {@link Module} if JIT binding provided.
 *
 * @param element guice SPI element
 * @return top module class name
 */
public static Class<? extends Module> getTopDeclarationModule(final Element element) {
    final List<String> modulesStack = getModules(element);
    // top most element is top most module (registered by user)
    return getModuleClass(modulesStack.get(modulesStack.size() - 1));
}