JSF 2.0碰到一个比较纠结的问题——上传文件

JSF 1.2之前还可以用MyFaces的组件，2.0还是个新玩意，只能靠自己。

开始的想法是自己做一个上传文件组件，组件中封装<input type="file" />，然后用commons-fileupload解析ServletRequest。

 

import org.apache.commons.fileupload.*;
import javax.faces.context.*;
import javax.servlet.http.HttpServletRequest;
import java.util.List;

@FacesComponent("uploadFile.UIUpload")
public class UIUpload extends UIInput {
    public UIUpload() {
        this.setRendererType(null);
    }

    @Override
    public void encodeBegin(FacesContext fc) throws IOException {
        ResponseWriter rw = fc.getResponseWriter();
        String clientId = this.getClientId(fc);
        rw.startElement("input", this);
        rw.writeAttribute("type", "file", null);
        rw.writeAttribute("name", clientId + ".file", null);
        rw.endElement("input");
    }

    @Override
    public void decode(FacesContext fc) {
        ExternalContext external = fc.getExternalContext();
        HttpServletRequest request = (HttpServletRequest) external.getRequest();
        String clientId = getClientId(fc);

        if(ServletFileUpload.isMultipartContent(request)) {
            FileItemFactory factory = new DiskFileItemFactory();
            ServletFileUpload upload = new ServletFileUpload(factory);
            try {
                List fileItems = upload.parseRequest(request);
                //......
            } catch (FileUploadException ex) {
                //......
            }
        }
    }
}