[英]Vertx & HK2 - Launching the application (dependency injection)
我正在嘗試構建具有Vert.x和HK2擴展名的應用程序以進行依賴項注入。 但是,我似乎找不到任何可以向我展示整個畫面的示例。
請注意,我是依賴注入的新手。
我做了如本示例所示的操作,但是在啟動應用程序時遇到了NoSuchMethodException,因為它試圖訪問verticle類(SimpleVerticle)中不存在的默認,無參數構造函數。
在我的build.gradle中,將mainClassName設置為'io.vertx.core.Launcher',在shadowJar清單屬性中,將“ Main-Verticle”設置為SimpleVerticle,如示例所示。
當然,我在某處缺少什么。 誰能告訴我我所缺少的內容,還是給我指出一些最新的完整示例?
build.gradle:
buildscript {
repositories {
mavenCentral()
}
}
plugins {
id 'java'
id 'application'
id 'com.github.johnrengelman.shadow' version '1.2.3'
id 'java-library'
id 'eclipse'
id 'idea'
id 'maven'
id 'groovy'
id 'jacoco'
}
group 'example'
version "${buildVersion}"
repositories {
mavenCentral()
}
sourceCompatibility = '1.8'
targetCompatibility = '1.8'
dependencies {
compile('io.vertx:vertx-core:3.4.2')
compile('io.vertx:vertx-web:3.4.2')
compile('javax.json:javax.json-api:1.1')
compile('org.glassfish:javax.json:1.0.4')
compile('log4j:log4j:1.2.17')
compile('io.vertx:vertx-web-client:3.4.2')
compile('com.englishtown.vertx:vertx-hk2:2.5.0')
testCompile "junit:junit:4.12"
testCompile "io.vertx:vertx-unit:3.3.3"
testCompile "com.jayway.restassured:rest-assured:2.4.0"
testImplementation 'junit:junit:4.12'
}
mainClassName = 'io.vertx.core.Launcher'
shadowJar {
classifier = 'fat'
baseName = 'aggregator-api'
manifest {
attributes "Main-Verticle": 'example.startup.StartupVerticle'
}
mergeServiceFiles {
include 'META-INF/services/io.vertx.core.spi.VerticleFactory'
}
}
StartupVerticle:
package example.startup;
import example.config.ConfigReader;
import io.vertx.core.AbstractVerticle;
import javax.inject.Inject;
public class StartupVerticle extends AbstractVerticle {
private final ConfigReader configReader;
@Inject
public StartupVerticle(final ConfigReader configReader) {
this.configReader = configReader;
}
@Override
public void start() throws Exception {
if(this.configReader == null) throw new IllegalStateException("ConfigReader was not injected!");
super.start();
System.out.println("Started verticle using DI");
}
}
ConfigBinder:
package example.binder;
import example.config.ConfigReader;
import example.config.ConfigReaderImpl;
import org.glassfish.hk2.utilities.binding.AbstractBinder;
public class ConfigBinder extends AbstractBinder {
@Override
protected void configure() {
this.bind(ConfigReaderImpl.class).to(ConfigReader.class);
}
}
ConfigReader:
package example.config;
import io.vertx.core.json.JsonObject;
public interface ConfigReader {
JsonObject getConfig();
}
ConfigReaderImpl:
package example.config;
import io.vertx.core.json.JsonObject;
public class ConfigReaderImpl implements ConfigReader {
private final JsonObject config;
ConfigReaderImpl(JsonObject config) {
this.config = config;
}
@Override
public JsonObject getConfig() {
return this.config;
}
}
設法修復它。
我切換到Guice,我為ConfigReaderImpl類的JsonObject注入丟失了一些東西
新的ConfigBinder:
public class ConfigBinder extends AbstractModule {
private final String CONFIG_PATH = "config";
@Override
protected void configure() {
this.bind(ConfigReader.class).to(ConfigReaderImpl.class).in(Scopes.NO_SCOPE);
this.bindConfig(Vertx.currentContext().config(), this.CONFIG_PATH);
}
private void bindConfig(JsonObject config, String path) {
this.bind(JsonObject.class).annotatedWith(Names.named(path)).toInstance(config);
}
}
我還缺少ConfigReaderImpl類中的注釋:
public class ConfigReaderImpl implements ConfigReader {
private final JsonObject config;
@Inject
private ConfigReaderImpl(@Named("config") final JsonObject config) {
this.config = config;
}
@Override
public JsonObject getConfig() {
return this.config;
}
}
我設法通過以下方式部署了依賴項注入的Verticle:
Injector injector = Guice.createInjector(new ConfigBinder());
Verticle verticle = injector.getInstance(SomeVerticle.class);
this.getVertx().deployVerticle(verticle);
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