文件上传限制超过primefaces大小时如何显示消息

FacesMessage message = new FacesMessage(FacesMessage.SEVERITY_ERROR, "文件上传失败", "文件大小超过限制");
FacesContext.getCurrentInstance().addMessage(null, message);

var fileInput = document.getElementById("fileInput");
var maxSize = 10 * 1024 * 1024; // 10MB
if (fileInput.files[0].size > maxSize) {
    alert("文件大小超过限制");
}

<p:fileUpload id="fileUpload" mode="advanced" dragDropSupport="false" fileLimit="1" 
    fileLimitMessage="只能上传一个文件" invalidSizeMessage="文件大小超过限制" 
    invalidFileMessage="无效的文件" />
<p:progressBar id="progressBar" widgetVar="progressBar" ajax="true" 
    value="#{bean.progress}" labelTemplate="{value}%" style="width:200px" />

public void handleFileUpload(FileUploadEvent event) {
    UploadedFile file = event.getFile();
    if (file.getSize() > maxSize) {
        FacesMessage message = new FacesMessage(FacesMessage.SEVERITY_ERROR, "文件上传失败", "文件大小超过限制");
        FacesContext.getCurrentInstance().addMessage(null, message);
    } else {
        // 处理文件上传逻辑
    }
}