java - 在java中从HTTPS下载

Question

我到处搜索答案，但我似乎无法找到如何从 HTTPS URL 下载。

注意:字符串:文件，是我想要将 URL 下载链接另存为的内容

首先我调用这个函数

String URL = "https://2pi.pw/dl/TimeChanger-1.0 (1.8.9).jar";
String File = "TimeChanger-1.0.jar";

try {
    downloadFile(URL, File);
} catch (IOException e1) {
    // TODO Auto-generated catch block
    e1.printStackTrace();
}

然后它运行:

private static final int BUFFER_SIZE = 4096;
public static void downloadFile(String fileURL, String saveDir)
        throws IOException {
    URL url = new URL(fileURL);
    HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
    httpConn.addRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:25.0) Gecko/20100101 Firefox/25.0");
    int responseCode = httpConn.getResponseCode();


    // always check HTTP response code first
    if (responseCode == HttpURLConnection.HTTP_OK) {
        String fileName = "";
        String disposition = httpConn.getHeaderField("Content-Disposition");
        String contentType = httpConn.getContentType();
        int contentLength = httpConn.getContentLength();

        if (disposition != null) {
            // extracts file name from header field
            int index = disposition.indexOf("filename=");
            if (index > 0) {
                fileName = disposition.substring(index + 10,
                        disposition.length() - 1);
            }
        } else {
            // extracts file name from URL
            fileName = fileURL.substring(fileURL.lastIndexOf("/") + 1,
                    fileURL.length());
        }

        System.out.println("Content-Type = " + contentType);
        System.out.println("Content-Disposition = " + disposition);
        System.out.println("Content-Length = " + contentLength);
        System.out.println("fileName = " + fileName);

        // opens input stream from the HTTP connection
        InputStream inputStream = httpConn.getInputStream();
        String saveFilePath = saveDir + File.separator + fileName;

        // opens an output stream to save into file
        FileOutputStream outputStream = new FileOutputStream(saveFilePath);

        int bytesRead = -1;
        byte[] buffer = new byte[BUFFER_SIZE];
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, bytesRead);
        }

        outputStream.close();
        inputStream.close();

        System.out.println("File downloaded");
    } else {
        System.out.println("No file to download. Server replied HTTP code: " + responseCode);
    }
    httpConn.disconnect();
}

目前正在回归

Content-Type = application/java-archive
Content-Disposition = null
Content-Length = 15089
fileName = TimeChanger-1.0 (1.8.9).jar
java.io.FileNotFoundException: TimeChanger-1.0.jar\TimeChanger-1.0 (1.8.9).jar (The system cannot find the path specified)
    at java.io.FileOutputStream.open0(Native Method)
    at java.io.FileOutputStream.open(Unknown Source)
    at java.io.FileOutputStream.<init>(Unknown Source)
    at java.io.FileOutputStream.<init>(Unknown Source)
    at client.SD.downloadFile(SD.java:173)
    at client.SD$2.actionPerformed(SD.java:85)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$500(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

Answer 1

您确定这不是目标中缺少父目录之一的问题吗？按照以下说明解决该问题:

FileOutputStream outputStream = new FileOutputStream(saveFilePath);