这个恢复下载的代码在Android中无法正常工作,尽管它在Java应用程序中运行良好。在这里,我试图下载一个zip文件,它将恢复下载,但最终结果是一个无效的zip文件。
BufferedInputStream in = null;
FileOutputStream fos = null;
BufferedOutputStream bout=null;
try {
downloaded=0;
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
if(ISSUE_DOWNLOAD_STATUS.intValue()==ECMConstant.ECM_DOWNLOADING){
File file=new File(DESTINATION_PATH);
if(file.exists()){
downloaded = (int) file.length();
}
}
connection.setRequestProperty("Range", "bytes=" + downloaded + "-");
connection.connect();
size=connection.getContentLength();
Dialog.setMax(size);
in = new BufferedInputStream(connection.getInputStream());
fos=(downloaded==0)? new FileOutputStream(DESTINATION_PATH): new FileOutputStream(DESTINATION_PATH,true);
bout = new BufferedOutputStream(fos, 1024);
byte[] data = new byte[1024];
int x = 0;
while ((x = in.read(data, 0, 1024)) >= 0) {
bout.write(data, 0, x);
downloaded += x;
System.out.println(downloaded);
onProgressUpdate((int)(downloaded*100/size));
}
succes=true;
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
in.close();
bout.close();
} catch (IOException e) {
e.printStackTrace();
}
}
感谢。
答案 0 :(得分:10)
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
int buf = 1024;
if (ISSUE_DOWNLOAD_STATUS.intValue() == ECMConstant.ECM_DOWNLOADING) {
File file = new File(DESTINATION_PATH);
if (file.exists()) {
downloaded = (int) file.length();
connection.setRequestProperty("Range",
"bytes=" + file.length() + "-");
}
} else {
connection.setRequestProperty("Range", "bytes=" + downloaded + "-");
}
connection.setDoInput(true);
connection.setDoOutput(true);
progressBar.setMax(connection.getContentLength());
in = new BufferedInputStream(connection.getInputStream());
fos = new FileOutputStream(DESTINATION_PATH, downloaded == 0 ? false : true);
bout = new BufferedOutputStream(fos, buf);
byte[] data = new byte[buf];
while ((int x = in.read(data, 0, buf)) >= 0) {
bout.write(data, 0, x);
downloaded += x;
progressBar.setProgress(downloaded);
}
答案 1 :(得分:3)
您的zip文件已损坏,因为您认为该流从您指定的范围字节中恢复。它实际上从头开始流,所以你有一个比原来大的文件。简而言之,您的服务器不支持范围属性。