public
class
Download
implements
Serializable {
private
static
final
int
START =
1
;
// 开始下载
private
static
final
int
PUBLISH =
2
;
// 更新进度
private
static
final
int
PAUSE =
3
;
// 暂停下载
private
static
final
int
CANCEL =
4
;
// 取消下载
private
static
final
int
ERROR =
5
;
// 下载错误
private
static
final
int
SUCCESS =
6
;
// 下载成功
private
static
final
int
GOON =
7
;
// 继续下载
private
static
ExecutorService mThreadPool;
// 线程池
static
{
mThreadPool = Executors.newFixedThreadPool(
5
);
// 默认5个
}
private
int
mDownloadId;
// 下载id
private
String mFileName;
// 本地保存文件名
private
String mUrl;
// 下载地址
private
String mLocalPath;
// 本地存放目录
private
boolean
isPause =
false
;
// 是否暂停
private
boolean
isCanceled =
false
;
// 是否手动停止下载
private
OnDownloadListener mListener;
// 监听器
/**
* 配置下载线程池的大小
* @param maxSize 同时下载的最大线程数
*/
public
static
void
configDownloadTheadPool(
int
maxSize) {
mThreadPool = Executors.newFixedThreadPool(maxSize);
}
/**
* 添加下载任务
* @param downloadId 下载任务的id
* @param url 下载地址
* @param localPath 本地存放地址
*/
public
Download(
int
downloadId, String url, String localPath) {
if
(!
new
File(localPath).exists()) {
new
File(localPath).mkdirs();
}
Log.log(
"下载地址；"
+ url);
mDownloadId = downloadId;
mUrl = url;
String[] tempArray = url.split(
"/"
);
mFileName = tempArray[tempArray.length-
1
];
mLocalPath = localPath;
}
/**
* 设置监听器
* @param listener 设置下载监听器
* @return this
*/
public
Download setOnDownloadListener(OnDownloadListener listener) {
mListener = listener;
return
this
;
}
/**
* 获取文件名
* @return 文件名
*/
public
String getFileName() {
return
mFileName;
}
/**
* 开始下载
* params isGoon是否为继续下载
*/
public
void
start(
final
boolean
isGoon) {
// 处理消息
final
Handler handler =
new
Handler() {
@Override
public
void
handleMessage(Message msg) {
switch
(msg.what) {
case
ERROR:
mListener.onError(mDownloadId);
break
;
case
CANCEL:
mListener.onCancel(mDownloadId);
break
;
case
PAUSE:
mListener.onPause(mDownloadId);
break
;
case
PUBLISH:
mListener.onPublish(mDownloadId, Long.parseLong(msg.obj.toString()));
break
;
case
SUCCESS:
mListener.onSuccess(mDownloadId);
break
;
case
START:
mListener.onStart(mDownloadId, Long.parseLong(msg.obj.toString()));
break
;
case
GOON:
mListener.onGoon(mDownloadId, Long.parseLong(msg.obj.toString()));
break
;
}
}
};
// 真正开始下载
mThreadPool.execute(
new
Runnable() {
@Override
public
void
run() {
download(isGoon,handler);
}
});
}
/**
* 下载方法
* @param handler 消息处理器
*/
private
void
download(
boolean
isGoon, Handler handler) {
Message msg =
null
;
Log.log(
"开始下载。。。"
);
try
{
RandomAccessFile localFile =
new
RandomAccessFile(
new
File(
mLocalPath + File.separator + mFileName),
"rwd"
);
DefaultHttpClient client =
new
DefaultHttpClient();
client.setParams(getHttpParams());
HttpGet get =
new
HttpGet(mUrl);
long
localFileLength = getLocalFileLength();
final
long
remoteFileLength = getRemoteFileLength();
long
downloadedLength = localFileLength;
// 远程文件不存在
if
(remoteFileLength == -1l) {
Log.log(
"下载文件不存在..."
);
localFile.close();
handler.sendEmptyMessage(ERROR);
return
;
}
// 本地文件存在
if
(localFileLength > -1l && localFileLength < remoteFileLength) {
Log.log(
"本地文件存在..."
);
localFile.seek(localFileLength);
get.addHeader(
"Range"
,
"bytes="
+ localFileLength +
"-"
+ remoteFileLength);
}
msg = Message.obtain();
// 如果不是继续下载
if
(!isGoon) {
// 发送开始下载的消息并获取文件大小的消息
msg.what = START;
msg.obj = remoteFileLength;
}
else
{
msg.what = GOON;
msg.obj = localFileLength;
}
handler.sendMessage(msg);
HttpResponse response = client.execute(get);
int
httpCode = response.getStatusLine().getStatusCode();
if
(httpCode >=
200
&& httpCode <=
300
) {
InputStream in = response.getEntity().getContent();
byte
[] bytes =
new
byte
[
1024
];
int
len = -
1
;
while
(-
1
!= (len = in.read(bytes))) {
localFile.write(bytes,
0
, len);
downloadedLength += len;
// Log.log((int)(downloadedLength/(float)remoteFileLength * 100));
if
((
int
)(downloadedLength/(
float
)remoteFileLength *
100
) %
10
==
0
) {
// 发送更新进度的消息
msg = Message.obtain();
msg.what = PUBLISH;
msg.obj = downloadedLength;
handler.sendMessage(msg);
// Log.log(mDownloadId + "已下载" + downloadedLength);
}
// 暂停下载， 退出方法
if
(isPause) {
// 发送暂停的消息
handler.sendEmptyMessage(PAUSE);
Log.log(
"下载暂停..."
);
break
;
}
// 取消下载， 删除文件并退出方法
if
(isCanceled) {
Log.log(
"手动关闭下载。。"
);
localFile.close();
client.getConnectionManager().shutdown();
new
File(mLocalPath + File.separator + mFileName)
.delete();
// 发送取消下载的消息
handler.sendEmptyMessage(CANCEL);
return
;
}
}
localFile.close();
client.getConnectionManager().shutdown();
// 发送下载完毕的消息
if
(!isPause) handler.sendEmptyMessage(SUCCESS);
}
}
catch
(Exception e) {
// 发送下载错误的消息
handler.sendEmptyMessage(ERROR);
}
}
/**
* 暂停/继续下载
* param pause 是否暂停下载
* 暂停 return true
* 继续 return false
*/
public
synchronized
boolean
pause(
boolean
pause) {
if
(!pause) {
Log.log(
"继续下载"
);
isPause =
false
;
start(
true
);
// 开始下载
}
else
{
Log.log(
"暂停下载"
);
isPause =
true
;
}
return
isPause;
}
/**
* 关闭下载， 会删除文件
*/
public
synchronized
void
cancel() {
isCanceled =
true
;
if
(isPause) {
new
File(mLocalPath + File.separator + mFileName)
.delete();
}
}
/**
* 获取本地文件大小
* @return 本地文件的大小 or 不存在返回-1
*/
public
synchronized
long
getLocalFileLength() {
long
size = -1l;
File localFile =
new
File(mLocalPath + File.separator + mFileName);
if
(localFile.exists()) {
size = localFile.length();
}
Log.log(
"本地文件大小"
+ size);
return
size <=
0
? -1l : size;
}
/**
* 获取远程文件打下 or 不存在返回-1
* @return
*/
public
synchronized
long
getRemoteFileLength() {
long
size = -1l;
try
{
DefaultHttpClient client =
new
DefaultHttpClient();
client.setParams(getHttpParams());
HttpGet get =
new
HttpGet(mUrl);
HttpResponse response = client.execute(get);
int
httpCode = response.getStatusLine().getStatusCode();
if
(httpCode >=
200
&& httpCode <=
300
) {
size = response.getEntity().getContentLength();
}
client.getConnectionManager().shutdown();
}
catch
(Exception e) {
e.printStackTrace();
}
Log.log(
"远程文件大小"
+ size);
return
size;
}
/**
* 设置http参数 不能设置soTimeout
* @return HttpParams http参数
*/
private
static
HttpParams getHttpParams() {
HttpParams params =
new
BasicHttpParams();
HttpProtocolParams.setContentCharset(params, HTTP.UTF_8);
HttpProtocolParams.setUseExpectContinue(params,
true
);
HttpProtocolParams
.setUserAgent(
params,
"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2041.4 Safari/537.36"
);
ConnManagerParams.setTimeout(params,
4000
);
HttpConnectionParams.setConnectionTimeout(params,
4000
);
return
params;
}
/**
* 关闭下载线程池
*/
public
static
void
closeDownloadThread() {
if
(
null
!= mThreadPool) {
mThreadPool.shutdownNow();
}
}
public
interface
OnDownloadListener {
public
void
onStart(
int
downloadId,
long
fileSize);
// 回调开始下载
public
void
onPublish(
int
downloadId,
long
size);
// 回调更新进度
public
void
onSuccess(
int
downloadId);
// 回调下载成功
public
void
onPause(
int
downloadId);
// 回调暂停
public
void
onError(
int
downloadId);
// 回调下载出错
public
void
onCancel(
int
downloadId);
// 回调取消下载
public
void
onGoon(
int
downloadId,
long
localSize);
// 回调继续下载
}
}
|
如何调用，如下：
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Download d =
new
Download(
1
,
"http://baidu.com/test.zip"
,
"/sdcard/download/"
);
d.setOnDownloadListener(
new
Download.OnDownloadListener() {
@Override
public
void
onSuccess(
int
downloadId) {
System.out.println(downloadId +
"下载成功"
);
}
@Override
public
void
onStart(
int
downloadId,
long
fileSize) {
System.out.println(downloadId +
"开始下载，文件大小："
+ fileSize);
}
@Override
public
void
onPublish(
int
downloadId,
long
size) {
System.out.println(
"更新文件"
+ downloadId +
"大小："
+ size);
}
@Override
public
void
onPause(
int
downloadId) {
System.out.println(
"暂停下载"
+ downloadId);
}
@Override
public
void
onGoon(
int
downloadId,
long
localSize) {
System.out.println(
"继续下载"
+ downloadId);
}
@Override
public
void
onError(
int
downloadId) {
System.out.println(
"下载出错"
+ downloadId);
}
@Override
public
void
onCancel(
int
downloadId) {
System.out.println(
"取消下载"
+ downloadId);
}
});
d.start(
false
);
|