file-upload - 如何限制使用<p:fileUpload>允许上传的文件数

如何限制在JSF 2 + primefaces应用程序中允许使用的文件上传数量。属性'filelimit'在primeface 3.3中存在，但我使用的是primefaces 3.4

最佳答案

看起来在Issue 3618中已删除fileLimit选项

如注释中所述，在后备Bean中使用一个计数器，并丢弃多余的文件或添加FacesMessage来通知用户已达到最大fileLimit。

代码示例:

@ManagedBean
@ViewScoped
public class FileUploadController {

    private final static int MAX_NUM_FILES = 3;
    private List<UploadedFile> uploadedFiles;
    private int counter = 0;

    @PostConstruct
    public void init() {
        uploadedFiles = new ArrayList<UploadedFile>();
    }


    public void handleFileUpload(FileUploadEvent event) {
        if (counter < MAX_NUM_FILES) {
            uploadedFiles.add(event.getFile());
            FacesMessage msg = new FacesMessage("Succesful", event.getFile().getFileName() + " is uploaded.");
            FacesContext.getCurrentInstance().addMessage(null, msg);
            counter ++;
        }
        else {
            FacesMessage msg = new FacesMessage(FacesMessage.SEVERITY_ERROR, "File Upload Limit Reached ", event.getFile().getFileName() + " is not uploaded.");
            FacesContext.getCurrentInstance().addMessage(null, msg);
        }

    }
}