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)); -"Hy%wE
} ~v+A6N:qC
for(int i=0;i<nEndPos.length-1;i++) 0.}WZAYy~
{ ygn]f*;?kw
nEndPos = nStartPos[i+1]; l'0fRQc
} YD|;xuh
nEndPos[nEndPos.length-1] = nFileLength; Nn]|#lLP
} WfF~\DlrD
} pNIu;1M5a
Tz{f5c&
{,`)
//启动子线程 Y~%9TC
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; oe*Y(T\G
for(int i=0;i<nStartPos.length;i++) Iurb?
{ [~#]p9|L
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <1(j&U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =@EX!]=x
nStartPos,nEndPos,i); (h3f$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?z$^4u3
fileSplitterFetch.start(); IGC:zZ~z
} Gl@}b\TB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OELh6R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~M!s0jT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]= nM|e
nEndPos = " + nFileLength); Sdn4y(&TP
// fileSplitterFetch[nPos.length-1].start(); Td"_To@jd
"cVJqW
]> dCt<
//等待子线程结束 "ke>O'
//int count = 0; py8)e7gX=
//是否结束while循环 ZN `D!e6
boolean breakWhile = false; 9C_Vb39::$
+M^+qt;]V
3+>;$
while(!bStop) +P5\N,,7R
{ %SHgXd#X
write_nPos(); yRF %SWO
Utility.sleep(500); {InD/l'v6n
breakWhile = true; ?@uyqi~:U
:t8?!9g
zm7IkYF
for(int i=0;i<nStartPos.length;i++) ^;@Q3~DpP%
{ f;7I{Z\<
if(!fileSplitterFetch.bDownOver) Pv3rDQ/Yt|
{ lI"~*"c`
breakWhile = false; 2LqJ.HH
break; @W+m;4HH
} oFC]L1HN&
} @P@j9yR
if(breakWhile) ]W9{<+&
break; aIXN wnq
>q!:*
ZP}NFh%,u
//count++; b|KlWt'
//if(count>4) f0d*%
// siteStop(); nB .?=eUa
} <bbC&O\
TyG;BF|rwk
2YV*U_\L
System.err.println("文件下载结束！"); oM~;du
} Pv#>j\OR&
catch(Exception e){e.printStackTrace ();} oZCjci-
} xP61^*-2
$9%UAqk9
_q7mYc
//获得文件长度 dbG5Cf#K\
public long getFileSize() zD z"Dn9
{ ;?K>dWf3f
int nFileLength = -1; %Xfy.v
try{ {I:nza
URL url = new URL(siteInfoBean.getSSiteURL()); 9iy3 dy^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q`{2yU:r
httpConnection.setRequestProperty("User-Agent","NetFox"); c ?(X(FQ
|_GESpoHH
31> $;"
int responseCode=httpConnection.getResponseCode(); h:3^FV&#
if(responseCode>=400) r-aCa/4y!
{ $(=0J*ND"
processErrorCode(responseCode); xb22:
return -2; //-2 represent access is error 8EBy5X}US
} OoqA`%
zHu w[
\zMx~-2oN
String sHeader; 5dXDL~/2p
j :$Ruy
4!k0
for(int i=1;;i++) .s8u?1b
{ &o]ic(74c?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aSVR+of
//Utility.log(in.readLine()); j+6`nN7L
sHeader=httpConnection.getHeaderFieldKey(i); pHKGK7 S-
if(sHeader!=null) 8`GN8F
{ &RL j^A!
if(sHeader.equals("Content-Length")) A/A;'9
{ +{dJGPoY]p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E$1P H)
break; |ycN)zuE
} OS]FGD3a
} N6thbH@
else *Q XUy
break; Y-fDYMm
} Y4j%K~lsY
} Yj'/ p
catch(IOException e){e.printStackTrace ();} iR39lOr
catch(Exception e){e.printStackTrace ();} \>N"{T
L2}p<?f
oH>G3n|U^
Utility.log(nFileLength); _p^&]eQ+k#
5`QN<4?%
dc=~EG-_rM
return nFileLength; 4ynGXJmMlR
} U6K!FOND
9tBE=L=
(D~NW*,9
//保存下载信息（文件指针位置） $s,Az_bs
private void write_nPos() W'3~vQF
{ 4E 32DG*
try{ <C{uodFll
output = new DataOutputStream(new FileOutputStream(tmpFile)); kBr?Q
output.writeInt(nStartPos.length); G'c6%;0)
for(int i=0;i<nStartPos.length;i++) e4<[|B!O
{ o)r%4YOL
// output.writeLong(nPos); x4^*YZc$,
output.writeLong(fileSplitterFetch.nStartPos); S>nf]J`
output.writeLong(fileSplitterFetch.nEndPos); B +<i=w
} $dkkgsw7
output.close(); ^w6~?'}
} <F6LC_
catch(IOException e){e.printStackTrace ();} j3&tXZ;F
catch(Exception e){e.printStackTrace ();} ~;D5j) 9I
} 2'T uS?
MNWuw;:v
=Yt)b/0b9
//读取保存的下载信息（文件指针位置） xI(t!aYp
private void read_nPos() >yr1wVS
{ sRaTRL2
try{ t^5xq8w8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;oGpB#[zO
int nCount = input.readInt(); ^6i,PRScS
nStartPos = new long[nCount]; d6vls7J/4
nEndPos = new long[nCount]; Q=n2frW(T
for(int i=0;i<nStartPos.length;i++) XZH\HK)K-]
{ k?VH4yA
nStartPos = input.readLong(); qfS ]vc_N
nEndPos = input.readLong(); *)xjMTJ%
} dQ`=CIr
input.close(); lSK<LytB
} r$<4_*
catch(IOException e){e.printStackTrace ();} rfHAz
catch(Exception e){e.printStackTrace ();} ("txj[v-/
} _4-UM2o;
s^zX9IVnp
.F^372hH3
private void processErrorCode(int nErrorCode) JGG(mrvR
{ q:vc;y
System.err.println("Error Code : " + nErrorCode); W`gzMx
} -v &
|@Sj:^cJD
:=e"D;5
//停止文件下载 ZMGthI}~-
public void siteStop() Z,JoxK2"
{ E9~}%&
bStop = true; h;JO"J@H
for(int i=0;i<nStartPos.length;i++) H%G|8,4
fileSplitterFetch.splitterStop(); -4LckY=]1
" gQJeMU
cTu"Tu\Qw
} wNQhg
} 2e|m3
//负责部分文件的抓取 X3Yi|dyn T
**FileSplitterFetch.java ~tB#Q6`nB
*/ ~d"9?K^#
package NetFox; TS49{^d$
HtAO9
o3,}X@p
import java.io.*; \SyG#.$
import java.net.*; .Hm1ispq
:O/QgGZN$
R}T\<6Y
public class FileSplitterFetch extends Thread { s]'EIw}mo
,ocAB;K
i>{.Y};
String sURL; //File URL [|tlTk
long nStartPos; //File Snippet Start Position #H-EOXy
long nEndPos; //File Snippet End Position kJk6lPSqi7
int nThreadID; //Thread's ID ,}a'h4C
boolean bDownOver = false; //Downing is over &b9bb{y_$K
boolean bStop = false; //Stop identical x't@Mc
FileAccessI fileAccessI = null; //File Access interface _qvzZ6
Sgq" 3(+%,
cllnYvr3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :7[4wQDt4
{ f <pJ_
this.sURL = sURL; r O-=):2
this.nStartPos = nStart; u`Abko<D
this.nEndPos = nEnd; ':#DROe!
nThreadID = id; :)DvZxHE@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h)pYV>!d
} qt`HP3J&
3F?_{A
!~fy".|x
public void run() 6YF<GF{
{ nl+8C}=u
while(nStartPos < nEndPos && !bStop) ,KFF[z
{ fX{Xw0
f?W"^6Df
5KC Zg'h
try{ l dw!G/
URL url = new URL(sURL); W,bu=2K6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bTc^huP
httpConnection.setRequestProperty("User-Agent","NetFox"); MwTouEGGgA
String sProperty = "bytes="+nStartPos+"-"; $VnPs!a
httpConnection.setRequestProperty("RANGE",sProperty); qc"PTv0q
Utility.log(sProperty); >?|c>HGX
{VT**o
"] [u
InputStream input = httpConnection.getInputStream(); pz ~REsx
//logResponseHead(httpConnection); Hd89./v`:
NEW0dF&)
qx";G
byte[] b = new byte[1024]; L17{W4
int nRead; wOn*QO[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8T}Dn\f
{ h)h%y)1
nStartPos += fileAccessI.write(b,0,nRead); 4MPR
//if(nThreadID == 1) k\Z@B!VAq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FJ{6_=@D
} =i:,")W7=
{+jO/ZQu5
Q3rLCg,;
Utility.log("Thread " + nThreadID + " is over!"); @j'GcN vs
bDownOver = true; 6!Uk c'r
//nPos = fileAccessI.write (b,0,nRead); ()(^B}VK
} 0 LQ%tn
catch(Exception e){e.printStackTrace ();} CS\8ej}y
} )*nZ6Cg'
} {-1N@*K
'H-hp
YYF.0G}
//打印回应的头信息 EpB3s{B"
public void logResponseHead(HttpURLConnection con) iH>IV0 <
{ =?[:Nj636
for(int i=1;;i++) =h,J!0Y
{ ?yKG\tPhM
String header=con.getHeaderFieldKey(i); `2hLs _
if(header!=null) n*rXj{Kt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VYnB&3%DF
Utility.log(header+" : "+con.getHeaderField(header)); C=x70Y/
else k|3hs('y|
break; vf?Xt
} tu6<>
} <6.?:Jj
4P}d/w?'KL
y/;DA=
public void splitterStop() dZuPR
{ ~WKWx.ul
bStop = true; Q& S 7_
} ]e(\<R6Gf
TTD#ovo'
w}0rDWuR[
} @YbZ"Jb
_V(FHjY
zuI7Px
/* (&Mv!6]
**FileAccess.java K)GpQ|4:<
*//文件访问(定位，写) ?^WX]SAl
package NetFox; 5V8`-yO9
import java.io.*; cp2a @
*0x!C8*`Xe
~T!D:2G
public class FileAccessI implements Serializable{ @T] G5|\ok
S2:G#%EAa
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~toR)=Yv
RandomAccessFile oSavedFile; <4P.B?-/t
long nPos; C=(~[Y
";TqYk=-
k,LaFe`W
public FileAccessI() throws IOException 7ea%mg\
{ &(h@]F!
this("",0); 9F7}1cH7g@
} XwDt8TxL
8@r>`c
!im%t9
public FileAccessI(String sName,long nPos) throws IOException wU-Cb<^
{ zICAV -&
oSavedFile = new RandomAccessFile(sName,"rw"); DaqlL
this.nPos = nPos; oF_ '<\ly=
oSavedFile.seek(nPos); ;i!$rL
} Z_s]2y1
F%$lcQ04%
0Ok[`r`
public synchronized int write(byte[] b,int nStart,int nLen) 2]V8-
{ X0]Se(
int n = -1; WF-^pfRq~
try{ I].ddR%
oSavedFile.write(b,nStart,nLen); 7>f)pfLM
n = nLen; ~^>g<YR[
} (dP9`Na]
catch(IOException e) 2XyC;RWJ%
{ {7.uwIW.1
e.printStackTrace (); c=aVYQ"2
} ,.AXQ#~&`
>nO[5
1rV9dM#F
return n; 7pM&))R
} b6g/SIae
c*",AZ>U
c=<^pCa9t1
} \6!s";=hQ
Ict+|<f
`HILsU=|
/* oI"gQFGu`u
**SiteInfoBean.java f!G%$?]
*/ ;ZTh(_7
package NetFox; p1s|JI
Up*6K=Tny
S+l>@wa)|
public class SiteInfoBean { 6C!TXV'
jF-0fK;)*
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private String sSiteURL; //Site's URL P_(<?0l
private String sFilePath; //Saved File's Path {6iHUK
private String sFileName; //Saved File's Name n1)].`
private int nSplitter; //Count of Splited Downloading File 0>:`|IGnT2
NN~PWy1opa
$'KhA6u
public SiteInfoBean() ~R7{gCqdr
{//nSplitter的缺省值为5 $E^*^({
//default value of nSplitter is 5 !J(6E:,b#
this("","","",5); +f,I$&d.V
} tDtqTB}
Qm4cuV-0{
5Zl7crA[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }DQ[C&
{ 9`!#5i)VU8
sSiteURL= sURL; zwK$ q=-:
sFilePath = sPath; W3&~[DS@~
sFileName = sName; Ox6^=D"
this.nSplitter = nSpiltter; TSj)XU {W
aZCxyoh+
D!D}mPi[
} 1~[GGl
be'&tsZ9
$it>*%
public String getSSiteURL() gXB&Sgjo
{ Y{L|ja%9?
return sSiteURL; jR{t=da
} iBCIJ!;
V,eH E5C
e)oi3d.wJf
public void setSSiteURL(String value) \oO&c
{ F2v9XMi
sSiteURL = value; B|SX?X
} E#n:d9WA:
f0g&=k{OD
6+Y@dJnPT
public String getSFilePath() EI@ep~
{ kv`5"pa7M
return sFilePath; +'UxO'v3]
} )T@+"Pw8t
\p\rPfY{>
g$mqAz<
public void setSFilePath(String value) %Gm4,+8P3o
{ WiFZY*iu5
sFilePath = value; >k(AQW5?
} y|YhDO
3Ael
%j?7O00@
public String getSFileName() >c.HH}O0W
{ 6H:EBj54?
return sFileName; {=_xze)
} Y4*?QBYA
*'R2Lo<C
>IHf5})R
public void setSFileName(String value) OgkbN`
{ (Jk:Qz5
sFileName = value; 2_){4+,fu
} 6/Z 8/PL
42 Sk`
LdyE*u_
public int getNSplitter() =[o/D0-Kn
{ 0*o=JM]
return nSplitter; G[!<mh4h|
} a0Q\]S
CvqUaHW@
;sd] IZ$#
public void setNSplitter(int nCount) IFWP&20
{ ~<[]l~`
nSplitter = nCount; iPrAB*
} Dz+R Q`Vn
} <(Ktf0'__
"`5BAv;u
]j<& :_
/* m ,TYF
**Utility.java ooT~R2u
*/ BO;LK-V
package NetFox; {4b8s%:!4
<nn!9V\C
RQ[6svfP
public class Utility { e6^iakSd.L
mC84fss
kk3G~o+
public Utility() S;S_<GX
{ BU;E6s>P
) 2Hl\"F
+K[H!fD
} P4~C0z
N9cUlrDO
//线程睡眠 ^v@& q
public static void sleep(int nSecond) U+g<lgH1J
{ kam\dn04
try{ !,PoH
Thread.sleep(nSecond); a5%IjgQ&z
} T8a!"lPP7
catch(Exception e) (1Ii86EP
{ R~(_m#6`:
e.printStackTrace (); uJ/&!q<3
} Cg&cz]*q|
} k'+Mc%pg4E
]}dAm S/
//日志 Q GDfX_
public static void log(String sMsg) kM/;R)3t4/
{ ;923^*\:F{
System.err.println(sMsg); Mhze!!
} b `.h+=3
JV9Ft,xk
'} LAZQ"
public static void log(int sMsg) !Ql&Ls
{ z c,Q
System.err.println(sMsg); lDhuL;9e
} /h73'"SpDy
} Iw) 'Yyg
qluaop
HCKj8-*
/* viR-h iD
**TestMethod.java <3c|S_|L*m
*/ k/V:QdD Sb
package NetFox; 1\+d 5Q0
S`GM#(t@_
Zw"K69A)
public class TestMethod { yTL<S'
NKb,>TO
Qz/1^xy
public TestMethod() ' fP`ET5
{ ///xx/weblogic60b2_win.exe 0CRk&_ht
try{ Se %"C&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S4BU!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w@ =Uf7
SiteFileFetch fileFetch = new SiteFileFetch(bean); Og~3eL[1%C
fileFetch.start(); T)PH8 "
} ;p'Ej'E
catch(Exception e){e.printStackTrace ();} %{M&"Mv
:0RfA%
U49 `!~b7
} +cnBEv~y
q%A.)1<'_
lGtTZcg
public static void main(String[] args) " )_-L8
{ Vtr5<:eEx
new TestMethod(); S^4T#/
} p/!P kKJ
} (}LLk+
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