Weblogic 12c环境下单PDF文件上传下载实现方案咨询

Alright, let's put together a complete, working implementation for your PDF upload/download feature—since you already have a Direct-Write File Store set up in Weblogic 12c, we'll build on that with Java 7 backend code and AngularJS frontend. Here's how to do it step by step:

1. Backend Java (Servlet) Setup #

We'll use two servlets: one for handling PDF downloads, another for accepting uploads to replace the existing file. Note that Java 7 (paired with Java EE 6) doesn't have built-in multipart file support, so we'll use Apache Commons FileUpload for upload handling.

1.1 First, Add Dependencies #

Download these JARs and place them in your web app's WEB-INF/lib folder:

• commons-fileupload-1.4.jar
• commons-io-2.11.0.jar (compatible with Java 7)

1.2 Download Servlet #

This servlet streams the stored PDF to the user's browser for download:

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;

@WebServlet("/downloadPdf")
public class PdfDownloadServlet extends HttpServlet {
    // Replace this with your Direct-Write File Store's physical directory path
    private static final String PDF_STORAGE_PATH = "/opt/weblogic/filestores/direct-write-store";
    private static final String STORED_PDF_NAME = "current-document.pdf";

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        File pdfFile = new File(PDF_STORAGE_PATH, STORED_PDF_NAME);
        
        if (!pdfFile.exists()) {
            response.sendError(HttpServletResponse.SC_NOT_FOUND, "No PDF available for download");
            return;
        }

        // Configure response headers for PDF download
        response.setContentType("application/pdf");
        response.setHeader("Content-Disposition", "attachment; filename=\"" + STORED_PDF_NAME + "\"");
        response.setContentLength((int) pdfFile.length());

        // Stream the file to the response
        try (InputStream inputStream = new FileInputStream(pdfFile);
             OutputStream outputStream = response.getOutputStream()) {
            
            byte[] buffer = new byte[4096];
            int bytesRead;
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bytesRead);
            }
        }
    }
}

1.3 Upload Servlet #

This servlet accepts a PDF upload, validates it, and replaces the existing stored file:

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.util.List;

@WebServlet("/uploadPdf")
public class PdfUploadServlet extends HttpServlet {
    private static final String PDF_STORAGE_PATH = "/opt/weblogic/filestores/direct-write-store";
    private static final String STORED_PDF_NAME = "current-document.pdf";
    private static final String ALLOWED_EXTENSION = "pdf";

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // Validate request is multipart
        if (!ServletFileUpload.isMultipartContent(request)) {
            response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Request must be multipart/form-data");
            return;
        }

        DiskFileItemFactory factory = new DiskFileItemFactory();
        ServletFileUpload upload = new ServletFileUpload(factory);

        try {
            List<FileItem> items = upload.parseRequest(request);
            for (FileItem item : items) {
                if (!item.isFormField()) {
                    String fileName = item.getName();
                    
                    // Validate file type
                    if (!fileName.toLowerCase().endsWith("." + ALLOWED_EXTENSION)) {
                        response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Only PDF files are allowed");
                        return;
                    }

                    // Replace existing file
                    File targetFile = new File(PDF_STORAGE_PATH, STORED_PDF_NAME);
                    item.write(targetFile);

                    response.setStatus(HttpServletResponse.SC_OK);
                    response.getWriter().write("PDF uploaded and replaced successfully");
                    return;
                }
            }
            response.sendError(HttpServletResponse.SC_BAD_REQUEST, "No file was selected for upload");
        } catch (FileUploadException e) {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Upload failed: " + e.getMessage());
        } catch (Exception e) {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Failed to save file: " + e.getMessage());
        }
    }
}

2. Frontend AngularJS Implementation #

We'll create a simple controller and template to handle the user interactions:

2.1 HTML Template #

<div ng-controller="PdfManagerController">
    <button ng-click="triggerDownload()" class="btn btn-primary">Download Current PDF</button>
    <br><br>
    <input type="file" id="pdfUploadInput" accept=".pdf" />
    <button ng-click="uploadNewPdf()" class="btn btn-success">Upload & Replace PDF</button>
    <div ng-if="statusMessage" class="mt-3 alert alert-info">{{statusMessage}}</div>
</div>

2.2 AngularJS Controller #

angular.module('yourAppModule').controller('PdfManagerController', ['$scope', '$http', '$window', function($scope, $http, $window) {
    // Replace with your web app's context path
    const APP_CONTEXT = '/your-web-app-context';

    $scope.triggerDownload = function() {
        // Open download link in a new tab to trigger browser download
        $window.open(`${APP_CONTEXT}/downloadPdf`, '_blank');
    };

    $scope.uploadNewPdf = function() {
        const fileInput = document.getElementById('pdfUploadInput');
        const selectedFile = fileInput.files[0];

        if (!selectedFile) {
            $scope.statusMessage = "Please select a PDF file first";
            return;
        }

        if (selectedFile.type !== 'application/pdf') {
            $scope.statusMessage = "Only PDF files are supported";
            return;
        }

        const formData = new FormData();
        formData.append('pdfFile', selectedFile);

        $http.post(`${APP_CONTEXT}/uploadPdf`, formData, {
            transformRequest: angular.identity,
            headers: {'Content-Type': undefined}
        }).then(function(response) {
            $scope.statusMessage = response.data;
            fileInput.value = ''; // Reset file input after successful upload
        }, function(error) {
            $scope.statusMessage = error.data || "Upload failed. Please try again.";
        });
    };
}]);

3. Weblogic Configuration Checks #

Since you already have a Direct-Write File Store, double-check these details:

• Confirm the Physical Directory path of your File Store and replace the PDF_STORAGE_PATH values in both servlets with this path.
• If Weblogic's security policy blocks file access, add this permission to your domain's weblogic.policy file:

  grant codeBase "file:/path/to/your/webapp/WEB-INF/lib/-" {
      permission java.io.FilePermission "/opt/weblogic/filestores/direct-write-store/-", "read,write";
  };
  

• Ensure your web app is deployed with Servlet 3.0 support (Weblogic 12c defaults to this, so @WebServlet annotations will work without manual web.xml mappings).

4. Testing Steps #

1. Initial Download Test: Deploy your app, then visit http://your-weblogic-server:port/your-web-app-context/downloadPdf—you'll get a 404 until you upload your first PDF.
2. Upload Test: Use the frontend upload button to select a local PDF. Check the status message for success.
3. Verify Replacement: Download the PDF again to confirm it's the new file you uploaded.
4. Troubleshooting: Check Weblogic's server logs (domain_home/servers/your-server/logs/your-server.log) for any file permission or path errors.

内容的提问来源于stack exchange，提问作者Ellone