无法使用java通过rest api从mysql中检索图像

Question

我的问题看似简单，但我无法找到答案。 通过 Java 和 JDBI，我能够从 MySQL 数据库中检索图像并将其存储在本地。 但是当我尝试使用休息 api 时，它会在附加的屏幕截图中给出错误。 我已经搜索了很多，但找不到解决方案。

堆栈跟踪如下：

 Type Exception Report
    Message java.lang.IllegalStateException: No container builder available for java.sql.Blob

    Description The server encountered an unexpected condition that prevented it from fulfilling the request.

    Exception

    javax.servlet.ServletException: java.lang.IllegalStateException: No container builder available for java.sql.Blob
    org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:489)
    org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:427)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:388)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:341)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:228)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

java.lang.IllegalStateException: No container builder available for java.sql.Blob
    org.skife.jdbi.v2.ContainerFactoryRegistry.createBuilderFor(ContainerFactoryRegistry.java:73)
    org.skife.jdbi.v2.Query.first(Query.java:271)
    org.skife.jdbi.v2.sqlobject.ResultReturnThing$SingleValueResultReturnThing.result(ResultReturnThing.java:110)
    org.skife.jdbi.v2.sqlobject.ResultReturnThing.map(ResultReturnThing.java:46)
    org.skife.jdbi.v2.sqlobject.QueryHandler.invoke(QueryHandler.java:43)
    org.skife.jdbi.v2.sqlobject.SqlObject.invoke(SqlObject.java:212)
    org.skife.jdbi.v2.sqlobject.SqlObject$3.intercept(SqlObject.java:127)
    org.skife.jdbi.v2.sqlobject.CloseInternalDoNotUseThisClass$$EnhancerByCGLIB$$8d85a881.retrieveImage(<generated>)
    com.sample.obs.factory.BooksFactory.retrieveImage(BooksFactory.java:188)
    com.sample.obs.model.Books.listAllBooks(Books.java:378)
    com.sample.obs.util.BooksRest.listAllBooks(BooksRest.java:29)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
     sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    java.lang.reflect.Method.invoke(Method.java:498)
    org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81)
    org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:144)
    org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:161)
    org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$TypeOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:205)
    org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:99)
    org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:389)
    org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:347)
    org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:102)
    org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:326)
    org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
    org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
    org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    org.glassfish.jersey.internal.Errors.process(Errors.java:267)
    org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317)
    org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:305)
    org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1154)
    org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:473)
    org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:427)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:388)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:341)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:228)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

在下面添加 rest api 和 listAllBooks 方法：

@GET
@Produces(MediaType.APPLICATION_JSON)
public final Books[] listAllBooks() {
    Books b = new Books();
    Books[] shelf = b.listAllBooks();
    return shelf;
}



public final Books[] listAllBooks() {
    Books[] bList = BooksFactory.listAllBooks();

    for(Books b: bList) {
      String path = "E:\\" + b.getBookId() + ".png";
      Blob imageBlob = BooksFactory.retrieveImage(b.getBookId());

      try {
        byte[] image = handleBlob(imageBlob);
        
        if (image != null) {
          FileOutputStream fos = new FileOutputStream(path);
          fos.write(image);
          fos.close();

          b.setImageUrl(path);
        } else {
          System.out.println("Image not available");
          b.setImageUrl(null);
        }
      } catch (FileNotFoundException e) {
        e.printStackTrace();
      } catch (IOException e) {
        e.printStackTrace();
      }
      int avail = BooksFactory.retrieveAvailableCopies(b.getBookId());
      b.setAvailableCopies(avail);
    }
    return bList;
  }

DAO 和 Factory 方法返回一个 Blob，我有一个用于从数据库中获取 Blob 的映射器。

请指导如何解决这个问题。

Answer 1

我终于找到了解决我的问题的方法。 我将以下代码添加到 dbi 对象。

dbi.registerContainerFactory(new ContainerFactory<Blob>(){

        @Override
        public boolean accepts(Class<?> arg0) {
          return false;
        }

        @Override
        public ContainerBuilder<Blob> newContainerBuilderFor(Class<?> arg0) {
          return newContainerBuilderFor(arg0);
        }
        
      });

我按照此链接获取解决方案。