文件上传下载工具类

import android.content.Context;

import android.os.Environment;

 

import java.io.ByteArrayOutputStream;

import java.io.DataOutputStream;

import java.io.File; 

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStream; 

import java.io.OutputStream;

import java.net.HttpURLConnection;

import java.net.MalformedURLException;

import java.net.ProtocolException;

import java.net.URL;

import java.util.UUID;

 

import com.mixiaofan.App;

 

public class DownloadUtil {

 

     private static final int TIME_OUT = 30*1000; //超时时间

 

     private static final String CHARSET = "utf-8"; //设置编码

 

     private DownloadUtil() {

        throw new UnsupportedOperationException("DownloadUtil cannot be instantiated");

     }

 

    /**

     * @param file  上传文件

     * @param RequestURL 上传文件URL

     * @return 服务器返回的信息，如果出错则返回为null

     */

     public static String uploadFile(File file,String RequestURL) {

         String BOUNDARY = UUID.randomUUID().toString(); //边界标识 随机生成 String PREFIX = "--" , LINE_END = "\r\n";

         String PREFIX = "--" , LINE_END = "\r\n";

         String CONTENT_TYPE = "multipart/form-data"; //内容类型

         try {

             URL url = new URL(RequestURL);

             HttpURLConnection conn = (HttpURLConnection) url.openConnection();

             conn.setReadTimeout(TIME_OUT);

             conn.setConnectTimeout(TIME_OUT);

             conn.setDoInput(true); //允许输入流

             conn.setDoOutput(true); //允许输出流

             conn.setUseCaches(false); //不允许使用缓存 

             conn.setRequestMethod("POST"); //请求方式 

             conn.setRequestProperty("Charset", CHARSET);

             conn.setRequestProperty("Cookie", "PHPSESSID=" + App.getSessionId());

             //设置编码 

             conn.setRequestProperty("connection", "keep-alive"); 

             conn.setRequestProperty("Content-Type", CONTENT_TYPE + ";boundary=" + BOUNDARY);

             if(file!=null) { 

                     /** * 当文件不为空，把文件包装并且上传 */

                     OutputStream outputSteam=conn.getOutputStream();

                     DataOutputStream dos = new DataOutputStream(outputSteam);

                     StringBuffer sb = new StringBuffer();

                     sb.append(PREFIX);

                     sb.append(BOUNDARY); sb.append(LINE_END);

                     /**

                     * 这里重点注意：

                     * name里面的值为服务器端需要key 只有这个key 才可以得到对应的文件

                     * filename是文件的名字，包含后缀名的 比如:abc.png

                     */

                     sb.append("Content-Disposition: form-data; name=\"img\"; filename=\""+file.getName()+"\""+LINE_END);

                     sb.append("Content-Type: application/octet-stream; charset="+CHARSET+LINE_END);

                     sb.append(LINE_END);

                     dos.write(sb.toString().getBytes());

                     InputStream is = new FileInputStream(file);

                     byte[] bytes = new byte[1024];

                     int len;

                     while((len=is.read(bytes))!=-1)

                     {

                        dos.write(bytes, 0, len);

                     }

                     is.close();

                     dos.write(LINE_END.getBytes());

                     byte[] end_data = (PREFIX+BOUNDARY+PREFIX+LINE_END).getBytes();

                     dos.write(end_data);

                     dos.flush();

                     /**

                     * 获取响应码 200=成功

                     * 当响应成功，获取响应的流

                     */

                     ByteArrayOutputStream bos = new ByteArrayOutputStream();

                     InputStream resultStream = conn.getInputStream();

                     len = -1;

                     byte [] buffer = new byte[1024*8];

                     while((len = resultStream.read(buffer)) != -1) {

                         bos.write(buffer,0,len);

                     }

                     resultStream.close();

                     bos.flush();

                     bos.close();

                     String info = new String(bos.toByteArray());

                     int res = conn.getResponseCode();

                     if(res==200){

                        return info;

                     }else {

                         return null;

                     }

                }

               } catch (MalformedURLException e) {

                    e.printStackTrace();

               } catch (ProtocolException e) {

                    e.printStackTrace();

               } catch (FileNotFoundException e) {

                    e.printStackTrace();

               } catch (IOException e) {

                     e.printStackTrace();

               }

         return null;

     }

 

     public static byte[] download(String urlStr) {

            HttpURLConnection conn = null;

            InputStream is = null;

            byte[] result = null;

            ByteArrayOutputStream bos = null;

            try {

                URL url = new URL(urlStr);

                conn = (HttpURLConnection) url.openConnection();

                conn.setRequestMethod("GET");

                conn.setConnectTimeout(TIME_OUT);

                conn.setReadTimeout(TIME_OUT);

                conn.setDoInput(true);

                conn.setUseCaches(false);//不使用缓存

                if(conn.getResponseCode() == 200) {

                    is = conn.getInputStream();

                    byte [] buffer = new byte[1024*8];

                    int len;

                    bos = new ByteArrayOutputStream();

                    while((len = is.read(buffer)) != -1) {

                        bos.write(buffer,0,len);

                    }

                    bos.flush();

                    result = bos.toByteArray();

                }

            } catch (MalformedURLException e) {

                e.printStackTrace();

            } catch (IOException e) {

                e.printStackTrace();

            } finally {

                try {

                    if(bos != null){

                        bos.close();

                    }

                    if (is != null) {

                        is.close();

                    }

                    if (conn != null)conn.disconnect();

                } catch (IOException e) {

                    e.printStackTrace();

                }

            }

            return result;

        }

 

    /**

     * 获取缓存文件

     */

     public static File getDiskCacheFile(Context context,String filename,boolean isExternal) {

        if(isExternal && (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))) {

            return new File(context.getExternalCacheDir(),filename);

        }else {

            return new File(context.getCacheDir(),filename);

        }

    }

 

    /**

     * 获取缓存文件目录

     */

     public static File getDiskCacheDirectory(Context context) {

        if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {

            return context.getExternalCacheDir();

        }else {

            return context.getCacheDir();

        }

    }

 }