如何将java.io.File转换为com.liferay.portal.kernel.util.File

Question

我在生活中工作我有这个函数:

public class NewPortlet extends MVCPortlet {
public void abc(ActionRequest arq,ActionResponse ars) throws Exception {
    UploadPortletRequest uploadRequest = PortalUtil.getUploadPortletRequest(arq);
    FileUploader fileUp = new FileUploaderImpl();
    fileUp.setFid(CounterLocalServiceUtil.increment("FileUploader.class"));
    File file = (File) uploadRequest.getFile("file");   
    byte[] bytes = FileUtil.getBytes(file);
    fileUp.setContent(Base64.objectToString(bytes));
    FileUploaderLocalServiceUtil.addFileUploader(fileUp);
}
}

Where File is of com.liferay.portal.kernel.util.File;我试图使用上述功能上传图像。我得到UI来上传图像，当我点击提交时，我得到以下错误:

ERROR [http-bio-8080-exec-37][render_portlet_jsp:154] java.lang.ClassCastException: java.io.File cannot be cast to com.liferay.portal.kernel.util.File
at com.test.image.test.NewPortlet.abc(NewPortlet.java:25)
at com.liferay.portal.kernel.portlet.LiferayPortlet.callActionMethod(LiferayPortlet.java:153)
at com.liferay.util.bridges.mvc.MVCPortlet.callActionMethod(MVCPortlet.java:250)
at com.liferay.portal.kernel.portlet.LiferayPortlet.processAction(LiferayPortlet.java:80)
at com.liferay.util.bridges.mvc.MVCPortlet.processAction(MVCPortlet.java:220)
at com.liferay.portlet.FilterChainImpl.doFilter(FilterChainImpl.java:70)
at com.liferay.portal.kernel.portlet.PortletFilterUtil.doFilter(PortletFilterUtil.java:48)
at com.liferay.portal.kernel.servlet.PortletServlet.service(PortletServlet.java:111)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:72)
at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilter.doFilter(InvokerFilter.java:73)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:593)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:530)
at com.liferay.portlet.InvokerPortletImpl.invoke(InvokerPortletImpl.java:534)
at com.liferay.portlet.InvokerPortletImpl.invokeAction(InvokerPortletImpl.java:579)

如何将java.io.File转换为com.liferay.portal.kernel.util.File?

Answer 1

不能将java.io.File转换为com.liferay.portal.kernel.util.File，因为java.io.File不实现com.liferay.portal.kernel.util.File接口。

请记住，只有当A 是- A B时，才能将A转换为B。

Answer 2

直接的答案是你不能…因为java.io.File不是com.liferay.portal.kernel.util.File接口的子类。

---

但真正的答案是，你可能根本不应该尝试com.liferay.portal.kernel.util.File接口。据我所知，它是某种utils类的接口…它没有任何明显的实现类。(坦率地说，我不明白为什么这个接口存在!)

事实上，我认为你应该这样做:

java.io.File file = ...
byte[] bytes = com.liferay.portal.kernel.util.FileUtil.getBytes(file);

或者:

java.io.File file = ...
com.liferay.portal.kernel.util.FileUtil fu = 
            new com.liferay.portal.kernel.util.FileUtil();
byte[] bytes = fu.getBytes(file);

(我使用完全限定名只是为了说明目的…)

这是基于Liferay 5.1 javadocs和我在这里找到的源代码。YMMV .