Android Http下載文件到手機內存與SDCard

訪問Internet和保存文件到SDCard上，首先要在mainifest.xml文件中加上下面的權限。

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>

gettextfilestring(String url)獲取文本文件內容

public String gettextfilestring(String url){
                InputStream input =getinputStream(url);
                StringBuffer sb = new StringBuffer("");
                BufferedReader bfr = new BufferedReader(new InputStreamReader(input));
                String line = "";
                try {
                        while((line=bfr.readLine())!=null){
                                sb.append(line);
                        }
                       
                } catch (IOException e) {
                        toasterror("流文件讀寫錯誤");
                        e.printStackTrace();
                }finally{
                        try {
                                bfr.close();
                        } catch (IOException e) {
                                toasterror("流文件未能正常關閉");
                                e.printStackTrace();
                        }
                }
                return sb.toString();
}

downFiletoDecive(String url,String filename)方法下載文件到設備內存，下載的文件在應用的路徑file下

public void downFiletoDecive(String url,String filename){
                    if((url!=null&&!"".equals(url))&&(filename!=null&&!"".equals(filename))){
                            InputStream input = getinputStream(url);
                            FileOutputStream outStream = null;
                            try {
                                    outStream = c.openFileOutput(filename, Context.MODE_WORLD_READABLE|Context.MODE_WORLD_WRITEABLE);
                                    int temp = 0;
                                    byte[] data = new byte[1024];
                                    while((temp = input.read(data))!=-1){
                                            outStream.write(data, 0, temp);
                                    }
                            } catch (FileNotFoundException e) {
                                    toasterror("請傳入正確的上下文");
                                    e.printStackTrace();
                            } catch (IOException e) {
                                    toastemessage("讀寫錯誤");
                                    e.printStackTrace();
                            }finally{
                                    try {
                                            outStream.flush();
                                            outStream.close();
                                    } catch (IOException e) {
                                            toasterror("流文件未能正常關閉");
                                            e.printStackTrace();
                                    }
                                   
                            }
                    }
                    toastemessage("下載成功");
            }

downFiletoSDCard(String url,String path,String filename)下載文件到SDCard中，自定義保存路徑

public void downFiletoSDCard(String url,String path,String filename){
               
                if((url!=null&&!"".equals(url))&&(path!=null)&&(filename!=null&&!"".equals(filename))){
                               
                                InputStream input = getinputStream(url);
                                downloader(input, path, filename);
                       
                }else{
                                /*
                                 * 對不合發的參數作處理
                                 */
                                if(url==null||"".equals(url)){
                                        toasterror("url不能爲空或爲「」");
                                }
                                if(path==null){
                                        toasterror("path不能爲空");
                                }
                                if(filename==null||"".equals(filename)){
                                        toasterror("filename不能爲空");
                                }
                }
               
        }