java - 如何将上传的文件保存在表单中，直到使用 jsf-2 和 primefaces-3.4 提交

Question

当我提交表单时，我有很多输入字段加上 primefaces 组件来上传多个文件“p:fileUpload”的表单我无法获取上传的文件..manged bean 是“RequestScoped”。那么如何在不设置managed bean View scope的情况下获取上传的文件呢？

上传方式

    public void upload(FileUploadEvent event) {
    try {
        FacesMessage msg = new FacesMessage("Success! ", event.getFile().getFileName() + " is uploaded.");
        FacesContext.getCurrentInstance().addMessage(null, msg);
        // Do what you want with the file
        String thumbnail = getDestination() + event.getFile().getFileName();
        int index = thumbnail.lastIndexOf('.');
        SystemFile systemFile = new SystemFile();
        systemFile.setAccount(getActor().getAccount());
        systemFile.setName(event.getFile().getFileName());
        systemFile.setPath(getTalentPath());

        systemFile.setFileType(FileUtil.checkFileType(thumbnail.substring(index + 1)));
        if (systemFiles == null) {
            systemFiles = new ArrayList<>();
        }
        systemFiles.add(systemFile);
        copyFile(event.getFile().getFileName(), event.getFile().getInputstream());
    } catch (IOException ex) {
        SystemLogger.getLogger(getClass().getSimpleName()).error(null, ex);
    }
}

primefaces 组件

    <p:fileUpload label="#{TalentMessages.lbl_Select_File}" fileUploadListener="#{talentPropertyAction.upload}"
                                  mode="advanced"
                                  multiple="true"
                                  uploadLabel="#{TalentMessages.lbl_upload_File}"
                                  cancelLabel="#{TalentMessages.lbl_cancel_File}"
                                  sizeLimit="2000000"
                                  oncomplete="completeUploadFile(#{talentPropertyAction.talentId});"
                                  />

然后是保存功能

    @Setter
@Getter
private List<SystemFile> systemFiles;
try {
 // save something else then save the files
        if (systemFiles != null) {
            System.out.println("Not Null" + systemFiles);
            for (SystemFile systemFile : systemFiles) {
                TalentPropertyFile talentPropertyFile = new TalentPropertyFile();
                talentPropertyFile.setTalentProperty(talentProperty);
                talentPropertyFile.setFile(systemFile);
                getTalentService().save(getActor().getAccount(), talentPropertyFile);
            }
        } else {
            System.out.println("Null");
        }
    } catch (InvalidParameter ex) {
        SystemLogger.getLogger(getClass().getName()).error(null, ex);
    }

Answer 1

So how can I get the uploaded files without making the manged bean View scope?

只需将上传信息立即存储在一个更永久的位置，而不是作为请求范围 bean 的属性，请求范围 bean 无论如何都会在请求-响应结束时被丢弃(注意:每次上传都算作一个单独的 HTTP 请求)。

public void upload(FileUploadEvent event) {
    // Now, store on disk or in DB immediately. Do not assign to a property.
}

public void save() {
    // Later, during submitting the form, just access them from there.
}

如果您需要一些 key 来访问它们，请考虑将 key 存储在 session 范围内。