JAVAでHttpURLConnectionを通じてファイルをアップロードし、ダウンロードする方法

本論文では、JAVAがHttpURLConnectionを通じてファイルをアップロードし、ダウンロードする方法を紹介します。
HttpURLConnectionファイルアップロード
HttpURLConnectionはアナログブラウザでアップロードされたデータフォーマットを使って、サーバーにアップロードします。
アップロードコードは以下の通りです。

package com.util;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Iterator;
import java.util.Map;

/**
 * Java   API     HTTP  ， java.net.URL、java.net.URLConnection，  API   、   ，
 *      ；
 * 
 * 1.         （java.net.URL）     （java.net.URLConnection） 2.        3.    
 * 4.              5.     
 * 
 * @author H__D
 *
 */
public class HttpConnectionUtil {


 /**
  *         
  * 
  * @param actionUrl：     
  * @param uploadFilePaths：         ，  
  * @return
  */
 @SuppressWarnings("finally")
 public static String uploadFile(String actionUrl, String[] uploadFilePaths) {
  String end = "\r
";
  String twoHyphens = "--";
  String boundary = "*****";

  DataOutputStream ds = null;
  InputStream inputStream = null;
  InputStreamReader inputStreamReader = null;
  BufferedReader reader = null;
  StringBuffer resultBuffer = new StringBuffer();
  String tempLine = null;

  try {
   //     
   URL url = new URL(actionUrl);
   //       ，   
   URLConnection urlConnection = url.openConnection();
   // http    
   HttpURLConnection httpURLConnection = (HttpURLConnection) urlConnection;

   //      httpUrlConnection  ，      true;
   httpURLConnection.setDoInput(true);
   //      httpUrlConnection  
   httpURLConnection.setDoOutput(true);
   // Post         
   httpURLConnection.setUseCaches(false);
   //        ，   GET
   httpURLConnection.setRequestMethod("POST");
   //           
   httpURLConnection.setRequestProperty("Connection", "Keep-Alive");
   //       
   httpURLConnection.setRequestProperty("Charset", "UTF-8");
   //         
   httpURLConnection.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);

   //   DataOutputStream
   ds = new DataOutputStream(httpURLConnection.getOutputStream());
   for (int i = 0; i < uploadFilePaths.length; i++) {
    String uploadFile = uploadFilePaths[i];
    String filename = uploadFile.substring(uploadFile.lastIndexOf("//") + 1);
    ds.writeBytes(twoHyphens + boundary + end);
    ds.writeBytes("Content-Disposition: form-data; " + "name=\"file" + i + "\";filename=\"" + filename
      + "\"" + end);
    ds.writeBytes(end);
    FileInputStream fStream = new FileInputStream(uploadFile);
    int bufferSize = 1024;
    byte[] buffer = new byte[bufferSize];
    int length = -1;
    while ((length = fStream.read(buffer)) != -1) {
     ds.write(buffer, 0, length);
    }
    ds.writeBytes(end);
    /* close streams */
    fStream.close();
   }
   ds.writeBytes(twoHyphens + boundary + twoHyphens + end);
   /* close streams */
   ds.flush();
   if (httpURLConnection.getResponseCode() >= 300) {
    throw new Exception(
      "HTTP Request is not success, Response code is " + httpURLConnection.getResponseCode());
   }

   if (httpURLConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
    inputStream = httpURLConnection.getInputStream();
    inputStreamReader = new InputStreamReader(inputStream);
    reader = new BufferedReader(inputStreamReader);
    tempLine = null;
    resultBuffer = new StringBuffer();
    while ((tempLine = reader.readLine()) != null) {
     resultBuffer.append(tempLine);
     resultBuffer.append("
");
    }
   }

  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } finally {
   if (ds != null) {
    try {
     ds.close();
    } catch (IOException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
   if (reader != null) {
    try {
     reader.close();
    } catch (IOException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
   if (inputStreamReader != null) {
    try {
     inputStreamReader.close();
    } catch (IOException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
   if (inputStream != null) {
    try {
     inputStream.close();
    } catch (IOException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }

   return resultBuffer.toString();
  }
 }


 public static void main(String[] args) {

  //       
   String str = uploadFile("http://127.0.0.1:8080/image/image.do",new String[] { "/Users//H__D/Desktop//1.png","//Users/H__D/Desktop/2.png" });
   System.out.println(str);


 }

}

HttpURLConnectionファイルのダウンロード
ダウンロードコードは以下の通りです。

package com.util;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Iterator;
import java.util.Map;

/**
 * Java   API     HTTP  ， java.net.URL、java.net.URLConnection，  API   、   ，
 *      ；
 * 
 * 1.         （java.net.URL）     （java.net.URLConnection） 2.        3.    
 * 4.              5.     
 * 
 * @author H__D
 *
 */
public class HttpConnectionUtil {


 /**
  * 
  * @param urlPath
  *       
  * @param downloadDir
  *         
  * @return       
  */
 public static File downloadFile(String urlPath, String downloadDir) {
  File file = null;
  try {
   //     
   URL url = new URL(urlPath);
   //       ，   
   URLConnection urlConnection = url.openConnection();
   // http    
   HttpURLConnection httpURLConnection = (HttpURLConnection) urlConnection;
   //        ，   GET
   httpURLConnection.setRequestMethod("POST");
   //       
   httpURLConnection.setRequestProperty("Charset", "UTF-8");
   //      URL           （           ）。
   httpURLConnection.connect();

   //     
   int fileLength = httpURLConnection.getContentLength();

   //    
   String filePathUrl = httpURLConnection.getURL().getFile();
   String fileFullName = filePathUrl.substring(filePathUrl.lastIndexOf(File.separatorChar) + 1);

   System.out.println("file length---->" + fileLength);

   URLConnection con = url.openConnection();

   BufferedInputStream bin = new BufferedInputStream(httpURLConnection.getInputStream());

   String path = downloadDir + File.separatorChar + fileFullName;
   file = new File(path);
   if (!file.getParentFile().exists()) {
    file.getParentFile().mkdirs();
   }
   OutputStream out = new FileOutputStream(file);
   int size = 0;
   int len = 0;
   byte[] buf = new byte[1024];
   while ((size = bin.read(buf)) != -1) {
    len += size;
    out.write(buf, 0, size);
    //        
    // System.out.println("   -------> " + len * 100 / fileLength +
    // "%
");
   }
   bin.close();
   out.close();
  } catch (MalformedURLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } finally {
   return file;
  }

 }

 public static void main(String[] args) {

  //       
  downloadFile("http://localhost:8080/images/1467523487190.png", "/Users/H__D/Desktop");

 }

}

以上が本文の全部です。皆さんの勉強に役に立つように、私たちを応援してください。