http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ?xX9o
} aI^Z0[P+
for(int i=0;i<nEndPos.length-1;i++) VelR8tjP
{ >n(Ga9E
nEndPos = nStartPos[i+1]; i`st'\I
} /u&{=nU
nEndPos[nEndPos.length-1] = nFileLength; n=_jmR1
} a|Yry
} S:F8`Gh
6O@/Y;5i
jVdRy{MH
//启动子线程 Rlyx&C8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3OZu v};k
for(int i=0;i<nStartPos.length;i++) .G/>X%X
{ I_"KhBM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )\3 RR.p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E!rgR5Bd
nStartPos,nEndPos,i); k\/idd[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {BI5lvx:
fileSplitterFetch.start(); |i~Ab!*8n
} AhA4IOG`.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q\uzmOh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a@?2T,$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q |1-j
nEndPos = " + nFileLength); HzdyfZ!jR
// fileSplitterFetch[nPos.length-1].start(); X6Wj,a
j84g6;4Dv
/$-Tg)o5i
//等待子线程结束 N"k IQe*}1
//int count = 0; 8`]1Nt!*B
//是否结束while循环 @a]O(S>Ub
boolean breakWhile = false; P/?'ea
{];8jdg/?
m,|)$R
while(!bStop) n97pxD_74
{ KEfx2{k b
write_nPos(); tqYwPSr
Utility.sleep(500); ]-+%]'
breakWhile = true; i*l-w4D^U
/9wmc2
>0c4C<_
for(int i=0;i<nStartPos.length;i++) V;-$k@$b.
{ 40i]I@:JK
if(!fileSplitterFetch.bDownOver) 4n5r<?rY
{ p*ic@n*G
breakWhile = false; -:]-g:;/
break; 2Y-NxW^]
} ~u^MRe|`
} QKVFH:"3
if(breakWhile) {wq~+O
break; [gE_\=FSKu
pf@H;QS`
^f?>;,<&
//count++; yzH[~O7
//if(count>4) 7}%Z>
// siteStop(); xC}9W6
} Ng 3r`S"_<
/$Ca}>
=Ul{#R z
System.err.println("文件下载结束！"); |Ym3.hz
} vlSSw+r9
catch(Exception e){e.printStackTrace ();} ,)beK*Iw
} P;7 Y9}
*kM^l!<g
8Ts_;uId
//获得文件长度 JQ"R%g`8
public long getFileSize() \YMe&[C:o
{ _7=LSf,9
int nFileLength = -1; tOT(!yz
try{ @en*JxIM
URL url = new URL(siteInfoBean.getSSiteURL()); *MD\YFXR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k[<Uxh%
httpConnection.setRequestProperty("User-Agent","NetFox"); -:~"c@D
[==x4Nb
G W@g
int responseCode=httpConnection.getResponseCode(); T@P[jtH<d
if(responseCode>=400) =+ vl+h
{ 0CR~ vQf#r
processErrorCode(responseCode); Uz$.sa
return -2; //-2 represent access is error bZf}m=C!
} Tk~Y
'fS&WVR?
<%ba 3<sg
String sHeader; UY~N4IR8
}P*x/z~
b-Xc6f
for(int i=1;;i++) &|Cd1z#?
{ I:=rwnd
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8kYI ~
//Utility.log(in.readLine()); ,We'AR3X
sHeader=httpConnection.getHeaderFieldKey(i); 4qvE2W}&
if(sHeader!=null) ({!S!k
{ ttfCiP$
if(sHeader.equals("Content-Length")) S!6 ? b5
{ H7?Sd(U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PW QRy
break; 0 P2lq
} HD!2|b~@
} g|=1U
else 0i4XS*vPv
break; 5lrjM^E|
} cP2n,>:
} 5KgAY;|
catch(IOException e){e.printStackTrace ();} tYUg%2G
catch(Exception e){e.printStackTrace ();} Y{D?&x%yq
`;HZO8
o>75s#= b=
Utility.log(nFileLength); _X)`S"EsJ
zJH:`~GxE
0@>
return nFileLength; |*>s%nF|
} JJ4w]Dd4
EV[ BB;eb
ZO8r8 [
//保存下载信息（文件指针位置） ',m!L@7M5
private void write_nPos() GV8`.3DBOF
{ L2> )HG
try{ Vi<6i0
output = new DataOutputStream(new FileOutputStream(tmpFile)); o7kQ&w
output.writeInt(nStartPos.length); zT+ "Z(oz,
for(int i=0;i<nStartPos.length;i++) *3#RS
{ b NR@d'U
// output.writeLong(nPos); mt\pndTy7!
output.writeLong(fileSplitterFetch.nStartPos); WXFCe@
output.writeLong(fileSplitterFetch.nEndPos); 4|h>.^
} O&}`R5Y;
output.close(); OLE@35"v]
} %@^9(xTE
catch(IOException e){e.printStackTrace ();} 91|~KR)
catch(Exception e){e.printStackTrace ();} |vY|jaV}
} s)}EMDY
17[vq!x6
DAQozhP8
//读取保存的下载信息（文件指针位置） UQO?hZ!y/.
private void read_nPos() d=/a{lP\
{ #C+7~ns'
try{ !yu-MpeG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7'RU\0QG
int nCount = input.readInt(); \:>eZl?
nStartPos = new long[nCount]; uO4R5F|tL
nEndPos = new long[nCount]; G\#dMCk?
for(int i=0;i<nStartPos.length;i++) \z?-
{ @!::_E+F]
nStartPos = input.readLong(); Z4{~
nEndPos = input.readLong(); X;d 1@G
} r?}L^bK
input.close(); #Kt5+"+7
} EHda
catch(IOException e){e.printStackTrace ();} /OeOL3Y
catch(Exception e){e.printStackTrace ();} ^K[[:7Aem
} c:,K{ZR
e89IT*
1G 63eH)!
private void processErrorCode(int nErrorCode) I ka V g L
{ g>H\"cUv
System.err.println("Error Code : " + nErrorCode); m-R`(
} J>^KQ
2qPQ3-'
>qci$
//停止文件下载 Z'_EX7r
public void siteStop() &I?d(Z=:\
{ Mf`@X[-;
bStop = true; 89[OaT_hs
for(int i=0;i<nStartPos.length;i++) 9`5qVM1O{
fileSplitterFetch.splitterStop(); CxJH)H$
wsAijHjJI!
X;3gKiD
} eG%Q 3h
} b_-?ZmV^r
//负责部分文件的抓取 YHI@Cj
**FileSplitterFetch.java 6q@VkzF
*/ Fes/8*-
package NetFox; (kZ2D
+t<'{KZ7;
wj|[a,(r
import java.io.*; 'L ]k\GO
import java.net.*; H(ds
Ui05o7xg~p
OM#eJ,MH<)
public class FileSplitterFetch extends Thread { 6"_ytqw7
Dt]*M_
PVX23y;
String sURL; //File URL "yc@_+"\+
long nStartPos; //File Snippet Start Position #mH4\s
long nEndPos; //File Snippet End Position *)um^O
int nThreadID; //Thread's ID Bey|f/ <
boolean bDownOver = false; //Downing is over o :_'R5
boolean bStop = false; //Stop identical TZ]o6Bb
FileAccessI fileAccessI = null; //File Access interface uI+^8-HZ;
_U`1BmTC2
}?=4pGsI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OjBg$f~0F
{ ^HI}bS1+|
this.sURL = sURL; E:S (v
this.nStartPos = nStart; :WnF>zN
this.nEndPos = nEnd; v="2p8@F
nThreadID = id; J?84WS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O`Ge|4
} 0ZjinWkR[
EmubpUS;
ylBjuD+
public void run() $C~OV@I
{ }^}ep2^
while(nStartPos < nEndPos && !bStop) B3-;]6
{ !i*bb~
2N[S*#~*e
<ZgbmRY8
try{ "I)`gy&
URL url = new URL(sURL); >(39K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3v7*@(y
httpConnection.setRequestProperty("User-Agent","NetFox"); O'~;|-Z<
String sProperty = "bytes="+nStartPos+"-"; GV(@(bI*
httpConnection.setRequestProperty("RANGE",sProperty); 5p`.RWls
Utility.log(sProperty); Y> f 6
X!ad~bt
9_<>#)u5
InputStream input = httpConnection.getInputStream(); xix:= a
//logResponseHead(httpConnection); "0#d F:qt
% C.I2J`_
#gd`X|<Ch
byte[] b = new byte[1024]; qZ|>{^a*
int nRead; |ZuS"'3_w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f=/IwMpn
{ n#lZRwhq
nStartPos += fileAccessI.write(b,0,nRead); o9#8q_D9
//if(nThreadID == 1) u?+i5=N9{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v"N%w1`.e
} MeXGE
ofIw7D*h
I#U"DwM
Utility.log("Thread " + nThreadID + " is over!"); .PJCBTe
bDownOver = true; mcFJ__3MAV
//nPos = fileAccessI.write (b,0,nRead); z c7P2@
} J52- qR/
catch(Exception e){e.printStackTrace ();} /a:sWmxMT
} zUCtH*
} pNIu;1M5a
TaI72"8
_Nmc1azS
//打印回应的头信息 ;+-Dg3
public void logResponseHead(HttpURLConnection con) 5h6c W
{ krI@N}OU
for(int i=1;;i++) O${B)C,
{ ym~
String header=con.getHeaderFieldKey(i); qe{:9
if(header!=null) x%d\}%]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jj$D6f/mOG
Utility.log(header+" : "+con.getHeaderField(header)); CV )v6f
else WQ>y;fi5/{
break; M~jV"OF=
} &W@#pG
} 6Yu&'[?H$
?@uyqi~:U
U&}v1wdZ3
public void splitterStop() $63_*9
{ "0ZBPp1q
bStop = true; }> pNf
} \p%,g&^ x
,/uVq G
Ga M:/.
} j{?ogFfi
MaS"V`NI
,VdNP
/* -cL{9r&X
**FileAccess.java v:7_ZD6kR
*//文件访问(定位，写) [')C]YQb=
package NetFox; ]8;2Oh
import java.io.*; 9H6%\#rw
jM%8h$&E
5tG\5
public class FileAccessI implements Serializable{ |h6u%t2AY
5H!6#pqM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "k'P #v{f
RandomAccessFile oSavedFile; EK=PY
long nPos; zHu w[
lv=rL
zS<idy F`
public FileAccessI() throws IOException f(Uo?_as
{ qQ T^d
this("",0); }VDJ
} &RL j^A!
:5, k64'D
La9:qpj
public FileAccessI(String sName,long nPos) throws IOException p1`")$
{ =`W#R
oSavedFile = new RandomAccessFile(sName,"rw"); +F@ZVMp
this.nPos = nPos; WTX!)H6Zv
oSavedFile.seek(nPos); $z[r(a^a
} f~-qjEWm
2[QyH'"^E
4ynGXJmMlR
public synchronized int write(byte[] b,int nStart,int nLen) S #6:!
{ JuM4Njz|
int n = -1; 5kdh!qy[$,
try{ OZn40"`
oSavedFile.write(b,nStart,nLen); $s`#&.>c-
n = nLen; >'g>CD!
} S>nf]J`
catch(IOException e) q2}6lf,J K
{ t=BXuFiu
e.printStackTrace (); j3&tXZ;F
} m!LJK`gA
-(1GmU5v(
O&@pi-=o
return n; M'>8P6O
} V \Sl->:
ibL
XZH\HK)K-]
} o%_Hmd;_'
K!jMW
c6~<vV'}
/* Gq0Q}[53
**SiteInfoBean.java kpLx?zW--q
*/ 0*F<tg,+]
package NetFox; `Ti?hQm/
Su*f`~G];
>))K%\p
public class SiteInfoBean { r";;Fk#5
ZMGthI}~-
`w K6B5>
private String sSiteURL; //Site's URL 4ztU) 1
private String sFilePath; //Saved File's Path e763yd
private String sFileName; //Saved File's Name >&D}^TMYY
private int nSplitter; //Count of Splited Downloading File X3Yi|dyn T
y$`@QRW
+Vw]DLWR
public SiteInfoBean() )Nnrsa
{//nSplitter的缺省值为5 o%)38T*n3
//default value of nSplitter is 5 +(/' b'*
this("","","",5); 4"d'iY
} 7(plHW|
g\Akf
A?4s+A@Eg
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~jDf,a2
{ Ux+UcBKm-
sSiteURL= sURL; Kw87 0n<
sFilePath = sPath; ~fY\;
sFileName = sName; ]CGH )4Pe
this.nSplitter = nSpiltter; <Wa7$hF
^ RIWW0
jSdW?IH
} YES-,;ZQ'
EPd
82KWe=
public String getSSiteURL() e_3($pj
{ *_H^]wNJG
return sSiteURL; |H&&80I
} "5b4fQ;x
s}g3*_"
bA02)?L
public void setSSiteURL(String value) i<-a-Z+^
{ ES ?6
sSiteURL = value; :@#6]W
} 80"oT'ZFh
fir#5,*q|
k\Z@B!VAq
public String getSFilePath() 1a_;(T
{ Ws;X;7tS
return sFilePath; "w{$d&+?ag
} K:54`UJ
CS\8ej}y
NKMVp/66D
public void setSFilePath(String value) &}!AjA)
{ j|%>NB ):
sFilePath = value; y1#*c$ O
} =h,J!0Y
oq[r+E-]$@
L7nW_
public String getSFileName() NS){D7T
{ cQrXrij;!
return sFileName; to(lE2`.da
} KskPFXxP
:4[_&]H
<{IeCir
public void setSFileName(String value) 9gac7(2`)
{ ?D['>Rzu
sFileName = value; *r|Zbxf(
} Qq3>Xv <
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gdkHaLL"
public int getNSplitter() -%TwtO<$']
{ ;jh.\a_\
return nSplitter; ~toR)=Yv
} A9y@v{txN
K6stkDhb
`$XgfMBf |
public void setNSplitter(int nCount) 9F7}1cH7g@
{ <jqL4!<
nSplitter = nCount; wU-Cb<^
} c3(0BSv
} 8=u88?Bh
y=zs6HaS
0Ok[`r`
/* F&HvSt}l5
**Utility.java SK5__Ix
*/ #rQT)n
package NetFox; `d4;T|f+=
r{wf;5d(
x LGMN)@r
public class Utility { \`W8#fob
lL&p?MUp
-qG7,t
public Utility() d?><+!a
{ 0%qM`KZC
(zw.?ADPCT
j]m|}n
} Yu:($//w
uFL!*#A
//线程睡眠 O^IS:\JX&
public static void sleep(int nSecond) +/rh8?
{ S*%:ID|/C2
try{ !L)yI#i4C
Thread.sleep(nSecond); 7e /Kh)5G
} ceAefKdb
catch(Exception e) JC9OL.Ob
{ :<uCi\9(
e.printStackTrace (); &Qt1~#1
} -v=tM6
} /Q'O]h0a
7eG@)5Uy
//日志 p7[&H/
public static void log(String sMsg) c[EG cY={
{ S9 @*g3
System.err.println(sMsg); i|fkwV,5
} cBU@853
MT<3OKo?:
uKo4nXVtp
public static void log(int sMsg) ihIRB9
{ :s|xa u=
System.err.println(sMsg); 3Z74&a$
} :U-yO 9!j
} M \>5",0
o+?Ko=vYw
/_r{7Gq.
/* \?AA:U*
**TestMethod.java P> ~Lx
*/ /P*ph0S-
package NetFox; /!-ypIY
*'R2Lo<C
PAu/iqCH
public class TestMethod { CxVrnb[`q
bc\?y2 3
e3kdIOu5
public TestMethod() bM $WU?Z
{ ///xx/weblogic60b2_win.exe M:w]g`LKl
try{ BF]+fs`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); IO?6F@(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O9F#gO|!
SiteFileFetch fileFetch = new SiteFileFetch(bean); JDBNi+t
fileFetch.start(); r'u[>uY
} \K(# r=
catch(Exception e){e.printStackTrace ();} ]BBjFs4#
DJHE6XJ
9|//_4]
} 9wv 7HD|
mOx>p"n
K|-RAjE
public static void main(String[] args) ^os|yRzV*M
{ ZAMS;e+e
new TestMethod(); mKBPIQ+ZS
} [T#9#3
} r$-]NYPi
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