使用 Java 类将文件上传到服务器

Question

我想创建一个允许将文件上传到远程服务器的 Java 应用程序（然后使其和小程序在网络上工作）。该文件之前已从服务器下载。我已经有了下载部分的代码，但对于上传部分，我有如下所示的代码。

导入库很好，但问题出在 Uploader 类上，它确实引发了错误.. 我认为我的 BufferReader 类缺少某些内容，但我需要您的帮助来调试它...

UploadApplet.java

import com.leo.upload.BufferReader;
import com.leo.upload.Uploader;
import java.awt.Color;
import java.awt.FileDialog;
import java.awt.Frame;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintStream;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import java.security.AccessControlException;
import java.security.AccessController;
import java.security.SecureRandom;
import java.util.Arrays;
import java.util.Properties;
import java.util.Random;
import java.util.logging.ConsoleHandler;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogManager;
import java.util.logging.Logger;
import java.util.logging.LoggingPermission;
import java.util.logging.SimpleFormatter;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.swing.JApplet;
import javax.swing.JPanel;
import netscape.javascript.JSObject;

public class UploadApplet extends JApplet {


      public void start()
      {
        super.start();
        uploadFile("/Users/XXXXX/Desktop/Tesing123.indd","http://xx.xx.xxx.xxx/");
      }


     public String uploadFile(String paramString1, String paramString2)
      {
        String str = "0";
        try {
          // I call the Uploader class to make the upload to the server
              str = (String)AccessController.doPrivileged(new Uploader(paramString1, paramString2));
          System.out.println(str);

        }
        catch (Exception e) {
            e.printStackTrace();
        }
        return str;
      }

Uploader.java

import com.leo.upload.BufferReader;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.security.PrivilegedAction;
import java.util.logging.Logger;
import javax.swing.JOptionPane;

public class Uploader
  implements PrivilegedAction<String>
{
  private static final String a = Uploader.class.getName();

  private Logger b = Logger.getLogger(a);
  private String c;
  private String d;

  public Uploader(String paramString1, String paramString2)
  {
    this.c = paramString1;
    this.d = paramString2;
  }

  public String run()
  {
    FileInputStream localFileInputStream = null;
    BufferedInputStream localBufferedInputStream = null;
    Writer localWriter = null;
    InputStream localInputStream = null;
    LineNumberReader localLineNumberReader = null;

    Object localObject1 = "0";
    try
    {
      File localFile = new File(this.c);
      localFileInputStream = new FileInputStream(localFile);
      localBufferedInputStream = new BufferedInputStream(localFileInputStream);

      Object localObject2 = new URL(this.d);
      URLConnection localURLConnection = ((URL)localObject2).openConnection();

      localURLConnection.addRequestProperty("Filename", localFile.getName());
      localURLConnection.setRequestProperty("Content-type", "application/binary");

      long l = localFile.length();
      Object localObject3;
      if (l <= 2147483647L) {
        if ((localURLConnection instanceof HttpURLConnection)) {
          localObject3 = (HttpURLConnection)localURLConnection;
          ((HttpURLConnection)localObject3).setFixedLengthStreamingMode((int)localFile.length());
        }

        localURLConnection.setDoOutput(true);

        **// I call the BufferReader class, and the a method to perform the writing**
        BufferReader.a(localBufferedInputStream, localURLConnection.getOutputStream());

        localInputStream = localURLConnection.getInputStream();
        localLineNumberReader = new LineNumberReader(new InputStreamReader(localInputStream, "UTF8"));
        localObject1 = localLineNumberReader.readLine();
      }
      else {
        localObject3 = "An error occurred during file upload: Cannot upload a file larger than 2GB.";
        JOptionPane.showMessageDialog(null, localObject3, "Error during file upload", 0);
        this.b.severe((String)localObject3);
        localObject1 = localObject3;
      }
    }
    catch (Throwable localIOException4) {
        localIOException4.printStackTrace();

      Object localObject2 = "An error occurred during file upload: " + localIOException4.toString();
      localObject1 = localObject2;
    } finally {
      BufferReader.a(localFileInputStream, localBufferedInputStream, localWriter);
      if (localLineNumberReader != null) {
        try {
          localLineNumberReader.close();
        } catch (IOException localIOException5) {
          localIOException5.printStackTrace();
        }
      }
      if (localInputStream != null) {
        try {
          localInputStream.close();
        } catch (IOException localIOException6) {
          localIOException6.printStackTrace();
        }
      }
    }
    return (String)(String)(String)localObject1;
  }


}

BufferReader.java

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.Writer;
import java.util.logging.Logger;

public final class BufferReader
{
  private static Logger logthis = Logger.getLogger(BufferReader.class.getName());

  public static void a(InputStream paramInputStream, OutputStream paramOutputStream)
    throws IOException
  {
    byte[] arrayOfByte = new byte[4096];
    int i = 0;
    int j;
    while ((j = paramInputStream.read(arrayOfByte)) != -1) {
      paramOutputStream.write(arrayOfByte, 0, j);
      i += j;
    }
    logthis.fine("CopyBytes : " + i);
  }

  public static void a(InputStream paramInputStream, FileOutputStream paramFileOutputStream, BufferedOutputStream paramBufferedOutputStream)
  {
    if (paramInputStream != null) {
      try {
        paramInputStream.close();
      } catch (IOException localIOException1) {
        localIOException1.printStackTrace();
      }
    }

    if (paramFileOutputStream != null) {
      try {
        paramFileOutputStream.flush();
      } catch (IOException localIOException2) {
        localIOException2.printStackTrace();
      }
    }

    if (paramBufferedOutputStream != null) {
      try {
        paramBufferedOutputStream.flush();
      } catch (IOException localIOException3) {
        localIOException3.printStackTrace();
      }
    }
    if (paramFileOutputStream != null) {
      try {
        paramFileOutputStream.close();
      } catch (IOException localIOException4) {
        localIOException4.printStackTrace();
      }
    }
    if (paramBufferedOutputStream != null)
      try {
        paramBufferedOutputStream.close();
      } catch (IOException localIOException5) {
        localIOException5.printStackTrace();
      }
  }

  public static void a(InputStream paramInputStream, BufferedInputStream paramBufferedInputStream, Writer paramWriter)
  {
    if (paramBufferedInputStream != null)
      try {
        paramBufferedInputStream.close();
      }
      catch (IOException localIOException1)
      {
      }
    if (paramInputStream != null)
      try {
        paramInputStream.close();
      }
      catch (IOException localIOException2)
      {
      }
    if (paramWriter != null)
      try {
        paramWriter.close();
      }
      catch (IOException localIOException3)
      {
      }
  }

  public static String a(InputStream paramInputStream)
    throws IOException
  {
    BufferedReader localBufferedReader = new BufferedReader(new InputStreamReader(paramInputStream, "UTF-8"));
    StringBuilder localStringBuilder = new StringBuilder();
    String str = null;

    while ((str = localBufferedReader.readLine()) != null) {
      localStringBuilder.append(str);
    }

    localBufferedReader.close();
    return localStringBuilder.toString();
  }
}

Answer 1

请记住，未签名的小程序通常不允许打开与不是其原始 Web 服务器的地址的连接...除非您指定小程序可以在客户端的 java 控制面板中执行它们想要的任何操作