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Dan Jasek
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Readd @config code. Move it to its own Guice module.
1 parent df973aa commit 6113917

14 files changed

Lines changed: 436 additions & 30 deletions

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‎README.md‎

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@@ -85,6 +85,54 @@ public class HelloWorldApplication extends Application<HelloWorldConfiguration>
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// you must have your health checks inherit from InjectableHealthCheck in order for them to be injected
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}
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}
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```
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Configuration data will be auto-injected and named. Use the provided @Config annotation to specify
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the path to the configuration data to be injected.
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```java
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public class HelloWorldConfiguration extends Configuration {
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@JsonProperty
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private String template;
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@JsonProperty
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private Person defaultPerson = new Person();
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public String getTemplate() { return template; }
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public Person getDefaultPerson() { return defaultPerson; }
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}
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public class Person {
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@JsonProperty
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private String name = "Stranger";
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private String city = "Unknown";
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public String getName() { return name; }
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}
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public class HelloWorldModule extends AbstractModule {
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// configuration data is available for injection and named based on the fields in the configuration objects
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@Inject
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@Config("template")
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private String template;
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// defaultPerson.name will only be available if the Person class is defined within the package path
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// set by addConfigPackages (see below)
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@Inject
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@Config("defaultPerson.name")
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private String defaultName;
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// A root config class may also be specified. The path provided will be relative to this root object.
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@Inject
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@Config(Person.class, "city")
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private String defaultCity;
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@Override
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protected void configure() {
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}
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}
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```
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Modules will also be injected before being added. Field injections only, constructor based injections will not be available.
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Configuration data and initialization module data will be available for injecting into modules.

‎src/main/java/com/hubspot/dropwizard/guice/ConfigData/Config.java‎

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@@ -0,0 +1,22 @@
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package com.hubspot.dropwizard.guice.ConfigData;
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import javax.inject.Qualifier;
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import java.lang.annotation.Retention;
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import java.lang.annotation.Documented;
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import static java.lang.annotation.RetentionPolicy.RUNTIME;
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/**
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* Guice {@linkplain Qualifier qualifier} that is bound
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* to fields in Dropwizard configuration objects.
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*/
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@Qualifier
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@Documented
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@Retention(RUNTIME)
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public @interface Config {
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/** The config path. */
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String value();
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/** The root config object to which the path is relative */
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Class root() default void.class;
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}

‎src/main/java/com/hubspot/dropwizard/guice/ConfigData/ConfigDataModule.java‎

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package com.hubspot.dropwizard.guice.ConfigData;
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import com.google.common.base.Function;
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import com.google.common.base.Joiner;
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import com.google.common.base.Preconditions;
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import com.google.common.collect.Lists;
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import com.google.common.collect.Maps;
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import com.google.inject.AbstractModule;
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import com.google.inject.Provider;
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import io.dropwizard.Configuration;
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import org.apache.commons.lang3.ArrayUtils;
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import org.apache.commons.lang3.ClassUtils;
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import org.apache.commons.lang3.reflect.FieldUtils;
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import java.lang.reflect.Field;
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import java.util.HashMap;
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import java.util.List;
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import java.util.Map;
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import java.util.Map.Entry;
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import static com.google.common.base.Throwables.propagate;
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import static java.lang.String.format;
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/**
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* Binds fields in the configurationClasses. Names field using the
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* @Config qualifier.
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* @param <T>
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*/
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public class ConfigDataModule<T extends Configuration> extends AbstractModule {
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private final T configuration;
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private final String[] configurationPackages;
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public ConfigDataModule(T configuration,
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String[] configurationPackages) {
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this.configuration = Preconditions.checkNotNull(configuration);
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Preconditions.checkNotNull(configurationPackages);
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this.configurationPackages = ensureTypeInPackages(configuration.getClass(), configurationPackages);
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}
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private String[] ensureTypeInPackages(Class<?> type, String[] packages) {
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String configName = type.getName();
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for(String pack : packages) {
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if(configName.startsWith(pack)) return packages;
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}
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return ArrayUtils.add(packages, configName);
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}
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@Override
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protected void configure() {
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bindConfigs();
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}
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private void bindConfigs() {
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HashMap<Class, String[]> roots = new HashMap<>();
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roots.put(void.class, new String[0]);
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bindConfigs(configuration.getClass(), roots, Lists.<Class<?>>newArrayList());
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}
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@SuppressWarnings("unchecked")
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private void bindConfigs(Class<?> config, Map<Class,String[]> roots, List<Class<?>> visited) {
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List<Class<?>> classes = Lists.newArrayList(ClassUtils.getAllSuperclasses(config));
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classes.add(config);
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for(Class<?> cls: classes) {
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//Only ever use a given class as a root once. Additional uses will have conflicting paths.
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boolean useAsRoot = false;
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if(!visited.contains(cls)) {
66+
useAsRoot = true;
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visited.add(cls);
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}
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for(Field field: cls.getDeclaredFields()) {
70+
Class<?> type = field.getType();
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final String name = field.getName();
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Map<Class, String[]> newRoots = Maps.newHashMap(Maps.transformValues(roots, new Function<String[], String[]>() {
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@Override
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public String[] apply(String[] path) {
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String[] subpath = new String[path.length + 1];
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System.arraycopy(path, 0, subpath, 0, path.length);
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subpath[path.length] = name;
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return subpath;
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}
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}));
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if(useAsRoot) newRoots.put(cls, new String[]{ name });
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ConfigElementProvider provider = new ConfigElementProvider(newRoots.get(void.class));
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for (Entry<Class, String[]> root : newRoots.entrySet()) {
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bind(type)
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.annotatedWith(new ConfigImpl(root.getKey(), Joiner.on(".").join(root.getValue())))
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.toProvider(provider);
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}
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if(!type.isEnum() && isInConfigPackage(type))
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bindConfigs(type, newRoots, visited);
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}
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}
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}
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private boolean isInConfigPackage(Class<?> type) {
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String name = type.getName();
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if(name == null) return false;
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for(String pack : configurationPackages) {
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if(name.startsWith(pack)) return true;
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}
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return false;
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}
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private class ConfigElementProvider<U> implements Provider<U> {
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private final Field[] path;
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public ConfigElementProvider(String[] path) {
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this.path = new Field[path.length];
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Class<?> cls = configuration.getClass();
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for(int i=0; i<path.length; i++) {
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this.path[i] = findField(cls, path[i]);
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cls = this.path[i].getType();
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}
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}
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private Field findField(final Class<?> cls, String name) {
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Field f;
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Class<?> search = cls;
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do {
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f = FieldUtils.getDeclaredField(search, name, true);
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if(f != null)
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return f;
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else
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search = search.getSuperclass();
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} while(!search.equals(Object.class));
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throw new IllegalStateException(format("Unable to find field %s on %s", name, cls.getName()));
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}
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@Override
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public U get() {
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Object obj = configuration;
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for(Field field: path) {
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try {
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obj = field.get(obj);
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if (obj == null) {
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return null; // Should cause an injection exception
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}
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} catch(IllegalAccessException e) {
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throw propagate(e);
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}
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}
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return (U) obj;
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}
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}
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}

‎src/main/java/com/hubspot/dropwizard/guice/ConfigData/ConfigImpl.java‎

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package com.hubspot.dropwizard.guice.ConfigData;
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import com.hubspot.dropwizard.guice.ConfigData.Config;
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import static com.google.common.base.Preconditions.checkNotNull;
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import java.io.Serializable;
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import java.lang.annotation.Annotation;
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public class ConfigImpl implements Config, Serializable {
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private final String value;
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private final Class root;
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public ConfigImpl(String value) {
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this.value = checkNotNull(value, "name");
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this.root = void.class;
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}
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public ConfigImpl(Class root, String value) {
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this.value = checkNotNull(value, "name");
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this.root = checkNotNull(root);
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}
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public String value() {
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return this.value;
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}
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public Class root() {
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return this.root;
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}
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public int hashCode() {
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// This is specified in java.lang.Annotation.
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return ((127 * "value".hashCode()) ^ value.hashCode()) +
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((127 * "root".hashCode()) ^ root.hashCode());
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}
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public boolean equals(Object o) {
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if (!(o instanceof Config)) {
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return false;
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}
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Config other = (Config) o;
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return value.equals(other.value()) &&
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root.equals(other.root());
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}
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public String toString() {
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return "@" + Config.class.getName() + "(root=" + root + ", " + "value=" + value + ")";
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}
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public Class<? extends Annotation> annotationType() {
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return Config.class;
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}
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private static final long serialVersionUID = 0;
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}

‎src/main/java/com/hubspot/dropwizard/guice/GuiceBundle.java‎

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import java.util.List;
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import com.google.inject.*;
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import com.hubspot.dropwizard.guice.ConfigData.ConfigDataModule;
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import io.dropwizard.setup.Bootstrap;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
@@ -30,6 +31,7 @@ public class GuiceBundle<T extends Configuration> implements ConfiguredBundle<T>
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private final List<Module> modules;
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private final List<Module> initModules;
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private final List<Function<Injector, ServletContextListener>> contextListenerGenerators;
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private final String[] configurationPackages;
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private final InjectorFactory injectorFactory;
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3537
private Injector initInjector;
@@ -45,6 +47,7 @@ public static class Builder<T extends Configuration> {
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private List<Function<Injector, ServletContextListener>> contextListenerGenerators = Lists.newArrayList();
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private Optional<Class<T>> configurationClass = Optional.absent();
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private InjectorFactory injectorFactory = new InjectorFactoryImpl();
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List<String> configurationPackages = new ArrayList<>();
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/**
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* Add a module to the bundle.
@@ -81,6 +84,17 @@ public Builder<T> setConfigClass(Class<T> clazz) {
8184
configurationClass = Optional.of(clazz);
8285
return this;
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}
87+
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/**
89+
* Sets a list of base packages that may contain configuration objects.
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* When config data is bound in the injector, classes within these
91+
* packages will be recursed into.
92+
*/
93+
public Builder<T> addConfigPackages(String... basePackages) {
94+
Preconditions.checkNotNull(basePackages.length > 0);
95+
configurationPackages.addAll(Arrays.asList(basePackages));
96+
return this;
97+
}
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8599
public Builder<T> setInjectorFactory(InjectorFactory factory) {
86100
Preconditions.checkNotNull(factory);
@@ -101,7 +115,7 @@ public GuiceBundle<T> build() {
101115

102116
public GuiceBundle<T> build(Stage s) {
103117
return new GuiceBundle<>(s, autoConfig, modules, initModules, contextListenerGenerators, injectorFactory,
104-
configurationClass);
118+
configurationClass, configurationPackages.toArray(new String[0]));
105119
}
106120

107121
}
@@ -116,17 +130,20 @@ private GuiceBundle(Stage stage,
116130
List<Module> initModules,
117131
List<Function<Injector, ServletContextListener>> contextListenerGenerators,
118132
InjectorFactory injectorFactory,
119-
Optional<Class<T>> configurationClass) {
133+
Optional<Class<T>> configurationClass,
134+
String[] configurationPackages) {
120135
Preconditions.checkNotNull(modules);
121136
Preconditions.checkArgument(!modules.isEmpty());
122137
Preconditions.checkNotNull(contextListenerGenerators);
123138
Preconditions.checkNotNull(stage);
139+
Preconditions.checkNotNull(configurationPackages);
124140
this.modules = modules;
125141
this.initModules = initModules;
126142
this.contextListenerGenerators = contextListenerGenerators;
127143
this.autoConfig = autoConfig;
128144
this.configurationClass = configurationClass;
129145
this.injectorFactory = injectorFactory;
146+
this.configurationPackages = configurationPackages;
130147
this.stage = stage;
131148
}
132149

@@ -165,10 +182,7 @@ public void run(final T configuration, final Environment environment) {
165182
void run(Bootstrap<T> bootstrap, Environment environment, final T configuration) {
166183
initEnvironmentModule();
167184
setEnvironment(bootstrap, environment, configuration);
168-
//The secondary injected modules generally use config data. If we are starting up a command
169-
//that doesn't have a configuration, loading these modules is useless at best.
170-
boolean addModules = configuration != null;
171-
initGuice(environment, addModules);
185+
initGuice(environment, configuration);
172186
Injector injector = getInjector().get();
173187

174188
if(environment != null) {
@@ -203,10 +217,16 @@ private void initEnvironmentModule() {
203217
}
204218
}
205219

206-
private void initGuice(final Environment environment, boolean addModules) {
207-
Injector environmentInjector = initInjector.createChildInjector(dropwizardEnvironmentModule);
220+
@SuppressWarnings("unchecked")
221+
private void initGuice(final Environment environment, T configuration) {
222+
List<Module> envModules = new ArrayList<>();
223+
envModules.add(dropwizardEnvironmentModule);
224+
if(configuration != null) envModules.add(new ConfigDataModule(configuration, configurationPackages));
225+
Injector environmentInjector = initInjector.createChildInjector(envModules);
208226

209-
if(addModules) {
227+
//The secondary injected modules generally use config data. If we are starting up a command
228+
//that doesn't have a configuration, loading these modules is useless at best.
229+
if(configuration != null) {
210230
for (Module module : modules)
211231
environmentInjector.injectMembers(module);
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