java - 如何使用java在tomcat webapps文件夹外读写图像

Question

我想在 tomcat 之外的本地 pc 文件夹(如 E:/CustomImage/Images/)中保存和检索图像。

这是我的服务等级

public class ImgUpload_Impl implements Serializable{
private static final long serialVersionUID = 1L;

 public void uploadImg(String imgPath, String fileName,UploadedFile uploadFile){
 ServletContext servletContext = (ServletContext) FacesContext.getCurrentInstance().getExternalContext().getContext();
String filepath = servletContext.getRealPath("/Images/"+imgPath) + File.separator + fileName;
try
   {
    InputStream is;
   try (FileOutputStream fos = new FileOutputStream(new File(filepath))) {
    is = uploadFile.getInputstream();
            int BUFFER_SIZE = 8192;
            byte[] buffer = new byte[BUFFER_SIZE];
            int a;
            while (true) {
            a = is.read(buffer);

                if (a < 0) {
                    break;
                }

                fos.write(buffer, 0, a);

                fos.flush();
            }  
        }
       is.close();
      } 
    catch (IOException e)
    {
        System.out.println("ImgUpload_Impl : uploadImg : "+e.getMessage());
    }
 }

}

这是我的 Controller 类

@ManagedBean
@Scope("session")
@Controller(value = "studentMB")
public class StudentMB{
private UploadedFile uploadedFile;
ImgUpLoad servicedao = new ImgUpload_Impl();

public void doRegistration(){
try{
 boolean imageContentType=servicedao.checkImageContenType(this.uploadedFile);
  if (!this.uploadedFile.getFileName().equals("") && imageContentType) {
  String imageFileName=stdRegBasicInfo.getStudentID()+"_stdimg.jpg";
   this.stdRegBasicInfo.setStudentName(imageFileName);//Here image name are save in database
    servicedao.uploadImgHeightWidth200("studentImage", imageFileName, this.uploadedFile);
 }
}catch(Exception e){
e.printStackTrace();
}
}

public UploadedFile getUploadedFile() {
    return uploadedFile;
}

public void setUploadedFile(UploadedFile uploadedFile) {
    this.uploadedFile = uploadedFile;
}

}

这是查看页面

 <ui:composition xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:p="http://primefaces.org/ui"
template="/WEB-INF/template/template.xhtml">

<ui:define name="content">
    <h:form>
        <p:outputLabel value="Student Image" />
        <p:fileUpload value="#{studentMB.uploadedFile}" skinSimple="true" 
          allowTypes="/(\.|\/)(gif|jpe?g|png)$/" mode="simple" />

        <p:commandButton value="Save" styleClass="btnSave" ajax="false"
            style="margin-left:12px" action="#{studentMB.doRegistration}"
            update="singlestd" icon="fa fa-save" />
    </h:form>
</ui:define>

当我上传并保存图片然后保存图片E:\Eduman.metadata.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\EduManager4\Images\studentImage\100122066717_stdimg.jpg 目录

但我想保存图片 *E:\CustomImage\Images* 目录

谢谢

Answer 1

为了使您的代码按预期工作，您需要通过替换行来修改 class ImgUpload_Impl

String filepath = servletContext.getRealPath("/Images/"+imgPath) + File.separator + fileName;

这个

String filepath = "E:\\CustomImage\\Images\\"+imgPath + File.separator + fileName;

不要忘记确保文件夹 E:\CustomImage\Images\studentImage 确实存在。如果它不存在，请从您的代码中手动或以编程方式创建它。

因为您稍后可能需要读取上传的图像，我建议您将字符串 "E:\\CustomImage\\Images\\" 定义为全局常量(static final)变量或如果有的话，将其移动到某些设置文件中。通过这种方式，您将能够更轻松地维护您的代码，并在有一天您需要更改它时拥有可配置的图像路径。