我不是一個Guice用戶,所以這個答案使用了Jersey的DI框架HK2。在基本配置級別,HK2與Guice配置沒有多大區別。例如Guice,你有AbstractModule
,其中HK2有AbstractBinder
。對於這兩個組件,您將使用類似的bind(..).to(..).in(Scope)
語法。與Guice不同的是,它是bind(Contract).to(Impl)
,而HK2則是bind(Impl).to(Contract)
。
HK2也有Factory
s,它允許更復雜的創建可注射對象。在您的工廠中,您可以使用語法bindFactory(YourFactory.class).to(YourContract.class)
。
這就是說,你可以實現你的用例如下所示。
創建英語SessionFactory
public class EnglishSessionFactoryFactory implements Factory<SessionFactory> {
@Override
public SessionFactory provide() {
...
}
@Override
public void dispose(SessionFactory t) {}
}
一個Factory
爲法國創建Factory
SessionFactory
public class FrenchSessionFactoryFactory implements Factory<SessionFactory> {
@Override
public SessionFactory provide() {
...
}
@Override
public void dispose(SessionFactory t) {}
}
注意上述兩個SessionFactory
旨意在單身範圍和被綁定名稱。
創建另一個Factory
,它將位於請求範圍內,它將使用請求上下文信息。該工廠將通過名稱(使用名稱綁定)注入上述兩個SessionFactory
,並從任何請求上下文信息中返回適當的SessionFactory
。下面簡單的例子使用的查詢參數
public class SessionFactoryFactory
extends AbstractContainerRequestValueFactory<SessionFactory> {
@Inject
@Named("EnglishSessionFactory")
private SessionFactory englishSessionFactory;
@Inject
@Named("FrenchSessionFactory")
private SessionFactory frenchSessionFactory;
@Override
public SessionFactory provide() {
ContainerRequest request = getContainerRequest();
String lang = request.getUriInfo().getQueryParameters().getFirst("lang");
if (lang != null && "fr".equals(lang)) {
return frenchSessionFactory;
}
return englishSessionFactory;
}
}
然後,你可以注入SessionFactory
(我們會給出一個不同的名稱)到你的道。
public class IDaoImpl implements IDao {
private final SessionFactory sessionFactory;
@Inject
public IDaoImpl(@Named("SessionFactory") SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
}
綁定在一起的一切,你將使用AbstractBinder
類似於以下實施
public class PersistenceBinder extends AbstractBinder {
@Override
protected void configure() {
bindFactory(EnglishSessionFactoryFactory.class).to(SessionFactory.class)
.named("EnglishSessionFactory").in(Singleton.class);
bindFactory(FrenchSessionFactoryFactory.class).to(SessionFactory.class)
.named("FrenchSessionFactory").in(Singleton.class);
bindFactory(SessionFactoryFactory.class)
.proxy(true)
.proxyForSameScope(false)
.to(SessionFactory.class)
.named("SessionFactory")
.in(RequestScoped.class);
bind(IDaoImpl.class).to(IDao.class).in(Singleton.class);
}
}
這裏有一些事情需要注意粘合劑
然後你只需要註冊澤西島AbstractBinder
。爲此,您可以使用ResourceConfig
的register(...)
方法。 See also,如果你需要web.xml配置。
就是這樣。以下是使用Jersey Test Framework的完整測試。您可以像其他任何JUnit測試一樣運行它。使用的SessionFactory
只是一個虛擬類,而不是實際的Hibernate SessionFactory
。只是儘可能縮短示例的範圍,但只需將其替換爲常規的Hibernate初始化代碼即可。
import java.util.logging.Logger;
import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.ExceptionMapper;
import org.glassfish.hk2.api.Factory;
import org.glassfish.hk2.utilities.binding.AbstractBinder;
import org.glassfish.jersey.filter.LoggingFilter;
import org.glassfish.jersey.process.internal.RequestScoped;
import org.glassfish.jersey.server.ContainerRequest;
import org.glassfish.jersey.server.ResourceConfig;
import org.glassfish.jersey.server.internal.inject.AbstractContainerRequestValueFactory;
import org.glassfish.jersey.test.JerseyTest;
import org.junit.Test;
import static junit.framework.Assert.assertEquals;
/**
* Stack Overflow https://stackoverflow.com/q/35189278/2587435
*
* Run this like any other JUnit test. There is only one required dependency
*
* <dependency>
* <groupId>org.glassfish.jersey.test-framework.providers</groupId>
* <artifactId>jersey-test-framework-provider-inmemory</artifactId>
* <version>${jersey2.version}</version>
* <scope>test</scope>
* </dependency>
*
* @author Paul Samsotha
*/
public class SessionFactoryContextTest extends JerseyTest {
public static interface SessionFactory {
Session openSession();
}
public static class Session {
private final String language;
public Session(String language) {
this.language = language;
}
public String get() {
return this.language;
}
}
public static class EnglishSessionFactoryFactory implements Factory<SessionFactory> {
@Override
public SessionFactory provide() {
return new SessionFactory() {
@Override
public Session openSession() {
return new Session("English");
}
};
}
@Override
public void dispose(SessionFactory t) {}
}
public static class FrenchSessionFactoryFactory implements Factory<SessionFactory> {
@Override
public SessionFactory provide() {
return new SessionFactory() {
@Override
public Session openSession() {
return new Session("French");
}
};
}
@Override
public void dispose(SessionFactory t) {}
}
public static class SessionFactoryFactory
extends AbstractContainerRequestValueFactory<SessionFactory> {
@Inject
@Named("EnglishSessionFactory")
private SessionFactory englishSessionFactory;
@Inject
@Named("FrenchSessionFactory")
private SessionFactory frenchSessionFactory;
@Override
public SessionFactory provide() {
ContainerRequest request = getContainerRequest();
String lang = request.getUriInfo().getQueryParameters().getFirst("lang");
if (lang != null && "fr".equals(lang)) {
return frenchSessionFactory;
}
return englishSessionFactory;
}
}
public static interface IDao {
public String get();
}
public static class IDaoImpl implements IDao {
private final SessionFactory sessionFactory;
@Inject
public IDaoImpl(@Named("SessionFactory") SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
@Override
public String get() {
return sessionFactory.openSession().get();
}
}
public static class PersistenceBinder extends AbstractBinder {
@Override
protected void configure() {
bindFactory(EnglishSessionFactoryFactory.class).to(SessionFactory.class)
.named("EnglishSessionFactory").in(Singleton.class);
bindFactory(FrenchSessionFactoryFactory.class).to(SessionFactory.class)
.named("FrenchSessionFactory").in(Singleton.class);
bindFactory(SessionFactoryFactory.class)
.proxy(true)
.proxyForSameScope(false)
.to(SessionFactory.class)
.named("SessionFactory")
.in(RequestScoped.class);
bind(IDaoImpl.class).to(IDao.class).in(Singleton.class);
}
}
@Path("test")
public static class TestResource {
private final IDao dao;
@Inject
public TestResource(IDao dao) {
this.dao = dao;
}
@GET
public String get() {
return dao.get();
}
}
private static class Mapper implements ExceptionMapper<Throwable> {
@Override
public Response toResponse(Throwable ex) {
ex.printStackTrace(System.err);
return Response.serverError().build();
}
}
@Override
public ResourceConfig configure() {
return new ResourceConfig(TestResource.class)
.register(new PersistenceBinder())
.register(new Mapper())
.register(new LoggingFilter(Logger.getAnonymousLogger(), true));
}
@Test
public void shouldReturnEnglish() {
final Response response = target("test").queryParam("lang", "en").request().get();
assertEquals(200, response.getStatus());
assertEquals("English", response.readEntity(String.class));
}
@Test
public void shouldReturnFrench() {
final Response response = target("test").queryParam("lang", "fr").request().get();
assertEquals(200, response.getStatus());
assertEquals("French", response.readEntity(String.class));
}
}
您可能還想考慮的另一件事是關閉SessionFactory
s。儘管Factory
有一個dispose()
方法,但澤西並不可靠地調用它。你可能想看看ApplicationEventListener
。您可以將SessionFactory
注入其中,並在關閉事件中關閉它們。
您使用的是什麼澤西版本? –
我們正在使用Jersey 2.19,不時更新未成年人 – vvondra