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)); cq4Ipe
} >Wg hn:^
for(int i=0;i<nEndPos.length-1;i++) ls)%c
{ {h`uV/5@`
nEndPos = nStartPos[i+1]; >`ZyG5
} | (_
nEndPos[nEndPos.length-1] = nFileLength; HT1!5
} \=0Vi6!Mc
} ZO c)
o J;$sj
rguCp}r
//启动子线程 Gjo`&#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u!qP
for(int i=0;i<nStartPos.length;i++) h>OfOx/{q9
{ 2x0<&Xy#P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hODWB&b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'Ne@e)s9
nStartPos,nEndPos,i); 0}quG^%_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aPbE;" f
fileSplitterFetch.start(); Q^txVUL
} dL )<% o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LTx,cP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0F><P?5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \.#>=!Ie
nEndPos = " + nFileLength); )U{Qj5W+F
// fileSplitterFetch[nPos.length-1].start(); NGOfb
K~uq,~
-5QZJF2~
//等待子线程结束 = 6\^%
//int count = 0; )~ h}
//是否结束while循环 d <JM36j?
boolean breakWhile = false; :1KpGj*F
(,Df^4%7
< F+l
while(!bStop) C/6V9;U
{ QbpFE)TYJ|
write_nPos(); D]Xsvv #
Utility.sleep(500); 55c|O
breakWhile = true; w%BL
M}v/tRI
54li^
for(int i=0;i<nStartPos.length;i++) +pn N!:q
{ cY.bO/&l
if(!fileSplitterFetch.bDownOver) ><HE;cVg?
{ l}sjD[2
breakWhile = false; W'+:'_{j:
break; n3 r3"~i
} j Dv{/)
} _8UDT^?8,
if(breakWhile) u.Tcg^v
break; L.0mk_&
]G< Vg5
v9O~@v{=
//count++; Q%mB|i|
//if(count>4) ':m,)G5&
// siteStop(); m<"WDU?y;
} HYSIN^<oy
tr}Loq\y
*CTlOy
System.err.println("文件下载结束！"); `t'W2X
} { W{]L:
catch(Exception e){e.printStackTrace ();} 0$fpIz
} N `F~n%N
7X'u6$i
R2]Z kg
//获得文件长度 dP]\Jo=Yh
public long getFileSize() `W/>XZl+t
{ ]R9HyCl&a6
int nFileLength = -1; 5 -RsnF
try{ 6h,(wo3Y
URL url = new URL(siteInfoBean.getSSiteURL()); j@uOOhy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e@* EzvO
httpConnection.setRequestProperty("User-Agent","NetFox"); ?\s+EE&-
K':;%~I
o@i#|kx,
int responseCode=httpConnection.getResponseCode(); ?[Q3q4
if(responseCode>=400) yx&51G$
{ ;8{4!S&b
processErrorCode(responseCode); C-6F]2:
return -2; //-2 represent access is error lHe{\N[C
} $Kncvu
Zu("#cA.H
c?&X?<
String sHeader; s6.M\^
@Y<bwv
;{tj2m,
for(int i=1;;i++) |My4SoOF
{ !1{e|p 7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %Ax3;g#
//Utility.log(in.readLine()); 3e;^/kf<9
sHeader=httpConnection.getHeaderFieldKey(i); Vi]W|bP
if(sHeader!=null) Rww{:R
{ kN4{13Qs*
if(sHeader.equals("Content-Length")) 6'G6<8>-
{ .|b$NM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K<ft2anY5
break; n+q!l&&
} OJ5#4qJ[
} !()$8
else wL 4dTc
break; }Nm#q@o$P
} jiS_G%G
} fc-iAj
catch(IOException e){e.printStackTrace ();} %Iv,@}kvT+
catch(Exception e){e.printStackTrace ();} S:oi<F
,J^b0@S
"haL
Utility.log(nFileLength); qr4pR-Gdr
yvHA7eq*"
YS@ypzc/
return nFileLength; J1I ;Jgql(
} ERE)A-8
X"e5Y!:M-
dP<=BcH>f
//保存下载信息（文件指针位置） EGzzHIZ`!
private void write_nPos() (b~T]3Es
{ 6qoyiT%P&
try{ [] `&vWZ
output = new DataOutputStream(new FileOutputStream(tmpFile)); QaS7z#/?.
output.writeInt(nStartPos.length); h WtVWVNL
for(int i=0;i<nStartPos.length;i++) 2ZMb<b4H
{ 33ef/MElD$
// output.writeLong(nPos); 6dN7_v)
output.writeLong(fileSplitterFetch.nStartPos); -vR5BMy=
output.writeLong(fileSplitterFetch.nEndPos); '\ey<}?5V
} B9$jSD
output.close(); lpeEpI/gM
} TKY*`?ct
catch(IOException e){e.printStackTrace ();} ,t9^j3Ixg
catch(Exception e){e.printStackTrace ();} y4I6
} q6SXWT'Sa
MVTMwwO\[
IE&!YP(U(
//读取保存的下载信息（文件指针位置） Vp*KfS]
private void read_nPos() v99B7VH4
{ uRRQyZ
try{ ,PuL{%PXu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r1.nTO%
int nCount = input.readInt(); $.PuK~}
nStartPos = new long[nCount]; 'y2nN=CN
nEndPos = new long[nCount]; uK$9Ll{lk
for(int i=0;i<nStartPos.length;i++) q[`]D7W "
{ !tMuuK?IL=
nStartPos = input.readLong(); BJB^m|b)
nEndPos = input.readLong(); g-HN
} P+PR<ZoI{f
input.close(); Xti[[sJ
} K/b_22]CC
catch(IOException e){e.printStackTrace ();} s(%oTKjt
catch(Exception e){e.printStackTrace ();} ;8*`{F[
} q<[_T
iZNts%Y]
{VvqO7A
private void processErrorCode(int nErrorCode) -UdEeZz.
{ [}/LD3
System.err.println("Error Code : " + nErrorCode); u7\J\r4,+
} (?`kYTw7g'
{QZUDPPR
*4xat:@{{
//停止文件下载 SHbtWq}T
public void siteStop() ~\.w^*$#Y
{ M?:c)&$]D
bStop = true; OK6]e3UO
for(int i=0;i<nStartPos.length;i++) ;04Ldb1{|3
fileSplitterFetch.splitterStop(); e8]\U/
8V)^R(\;
r>"
} *x])Y~oQ
} ?^$MRa:D
//负责部分文件的抓取 oA7;.:3
**FileSplitterFetch.java V7[zAq
*/ LbG_z =A
package NetFox; J'fQW<T4wU
jbu8~\"
8p9bCE>\
import java.io.*; #u"k~La
import java.net.*; j>x-"9N
T[uiPs/xD
S<u-n8bv
public class FileSplitterFetch extends Thread { =p?WBZT|:
4EZ9hA9+
n9A7K$ZD@
String sURL; //File URL bQP{|
long nStartPos; //File Snippet Start Position ->O2I?
long nEndPos; //File Snippet End Position W#BM(I
int nThreadID; //Thread's ID x~{;TZa[I
boolean bDownOver = false; //Downing is over 5ish\"
boolean bStop = false; //Stop identical {%{`l-
FileAccessI fileAccessI = null; //File Access interface PSVc+s[Q+V
`v}%33$hA
8J~1-;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !Mim@!5M
{ &f^l^K5:
this.sURL = sURL; Jn3An
this.nStartPos = nStart; *l;B\=KR
this.nEndPos = nEnd; $Y_i4(
nThreadID = id; 1jPJw3"3h
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &S]@Ot<z
} F;[T#N:~
7.@TK&
%]6~Eq%s
public void run() @@rEs40
{ ,0~9dS
while(nStartPos < nEndPos && !bStop) P=&o%K,:f
{ <Ib[82PU
vab@-=%k
tBT<EV{ G
try{ d&u]WVU
URL url = new URL(sURL); o{EC&-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iMFgmM|
httpConnection.setRequestProperty("User-Agent","NetFox"); E%v?t1>/
String sProperty = "bytes="+nStartPos+"-"; Wg0g/
httpConnection.setRequestProperty("RANGE",sProperty); Ns0cgCrhX
Utility.log(sProperty); )+"'oY$]}
|t)}VM%
!x>%+&c>k
InputStream input = httpConnection.getInputStream(); iNWo"=J
//logResponseHead(httpConnection); \uq/x^?yo
~7t$MF.
,4,V4 N
byte[] b = new byte[1024]; /K{9OT@>
int nRead; ""h)LUrl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )a3J9a;ZS0
{ L%$|^T=%
nStartPos += fileAccessI.write(b,0,nRead); E+tB&
//if(nThreadID == 1) RJH,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .8uz 6~
} bY2 C]r(n
_s$_Sa ;
RZ7(J
Utility.log("Thread " + nThreadID + " is over!"); .tmiQ.
bDownOver = true; N!x =eC
//nPos = fileAccessI.write (b,0,nRead); 6uKMCQ=h
} e9Pk"HHl
catch(Exception e){e.printStackTrace ();} ~-t>z
} UMp/\&0
} A@D2+fS
e)IpPTj#
ym/fFm6h
//打印回应的头信息 KdUnD4d
public void logResponseHead(HttpURLConnection con) rVa?JvDO=
{ |?,[@z _,
for(int i=1;;i++) 7`H 1f]d
{ 6^n0[7
String header=con.getHeaderFieldKey(i); k@D0 {z
if(header!=null) I3:[= ,5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (?kl$~&|
Utility.log(header+" : "+con.getHeaderField(header)); l|+BC
else ?D)<,
break; TLf9>= OVh
} x]{E)d"!
} qG/fE'(j&
pdb1GDl0q
CGP3qHrXt
public void splitterStop() Bo+DJizu
{ _l], "[d
bStop = true; Ty@=yA17
} ,j ',x\
).HDru-2
*tX{MSYW
} 9Sq%s&
%q322->Z
hv$m4,0WB
/* f8<o8*`7
**FileAccess.java R%H$%cnj
*//文件访问(定位，写) b7\ cxgRq
package NetFox; \zkw2*t
import java.io.*; $hVYTy~}
]PP:oriWl
";w}3+R
public class FileAccessI implements Serializable{ MfBdNdox7
gbStAr.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A+wv-~3
RandomAccessFile oSavedFile; FNQX7O52
long nPos; {8EW)4Hf
~;OYtz
25|8nfeC5
public FileAccessI() throws IOException @l(vYJ:f
{ T\# *S0^
this("",0); Ekm7 )d$
} 6V+ qnUk
nCvPB/-
]43bere
public FileAccessI(String sName,long nPos) throws IOException (5Tvsw`
{ }^K/?dM
oSavedFile = new RandomAccessFile(sName,"rw"); }T0K^Oe+eS
this.nPos = nPos; p(m1O70C
oSavedFile.seek(nPos); qy!Ou3^
} YIp-Y}6
wj|x:YZ*
>7U>Yh
public synchronized int write(byte[] b,int nStart,int nLen) j#6|V]l
{ &MgeYpd
int n = -1; \hP=-J[~C
try{ jN+N(pIi.o
oSavedFile.write(b,nStart,nLen); X7|.T0{=x
n = nLen; QI[}(O7#6
} 0gF!!m
catch(IOException e) cM&'[CI
{ HT_TP q
e.printStackTrace (); Y/8K;U|
} 2o[IHO]
GfyX'(ge
|\uYv|sT
return n; bv dR"G
} Er:?M_ev
=S]a&*M
Px'!;
} F[7x*-NO-
` e{BId
B7-RU<n
/* 9f}XRz
**SiteInfoBean.java dj[apuiF
*/ 4*UP.r@
package NetFox; :PnSQjV:
8C.!V =@\
I]J*BD#n.
public class SiteInfoBean { /=#~
!m{2WW-
9-bG<`v\E
private String sSiteURL; //Site's URL Lg`Jp&Kg
private String sFilePath; //Saved File's Path , Ut Hc]
private String sFileName; //Saved File's Name [ij,RE7,T
private int nSplitter; //Count of Splited Downloading File g>7Y~_}
{lzG*4?
gw3NS8 A+
public SiteInfoBean() z]$j7dp
{//nSplitter的缺省值为5 D\T!4q'Q
//default value of nSplitter is 5 X`\:_|
this("","","",5); qGPb
} %bX0 mN
MdhT!?
R/<=mZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,i++fOnQ
{ L,-u.vV
sSiteURL= sURL; JAn1{<Ky
sFilePath = sPath; ]s|lxqP
sFileName = sName; G\Q9IcJ0dY
this.nSplitter = nSpiltter; Inuc(_I
?Nl"sVCo
>e8JK*Blz
} bv\ A,+
0B0G2t&hr
?SUQk55w
public String getSSiteURL() T2Z[AvNXFk
{ <e6=% 9
return sSiteURL; {=At#*=A
} }NX\~S"
liNON
Q.(51]'
public void setSSiteURL(String value) 1BD6l2y
{ + >sci
sSiteURL = value; VvgN3e[
} $M]%vG
A"/aGCG0z
>7>7/7=O
public String getSFilePath() %9c|%#3
{ +X!+'>
return sFilePath; .9\Cy4_qSd
} Jc~E"x
J7a-CI_Tf
~! Lw1]&
public void setSFilePath(String value) .wFU:y4r
{ z(d4)z 8'6
sFilePath = value; lfMH1llx
} .g-3e"@
{u]CHN`%Z
TSyzdnMvz
public String getSFileName() o#d$[oa
{ L/k40cEI^z
return sFileName; WX*cICb5
} mvf _@2^
hrlCKL&
O~Uw&Bq
public void setSFileName(String value) _XN~@5elrC
{ F|]rA*2u
sFileName = value; 9c5!\m1
} oBUh]sR{.
&8Wlps`
]b\WaS8I
public int getNSplitter() Rk[8Bd?
{ iH _"W+dq
return nSplitter; *7vue"I*Z
} ^X;JT=r
.xv^G?GG
Z)v)\l9d
public void setNSplitter(int nCount) 0P:F97"1,
{ 'j /q76uXV
nSplitter = nCount; <<BQYU)Ig
} lIy/;hIc
} cJ4S!
)K.R\]XR
uf0^E3H
/* V9$-twhu
**Utility.java :A$wX$H01
*/ ArdJ."
package NetFox; 8c?8X=|D7
Alh?0Fk3)
vj@V !j?
public class Utility { ) hPVX()O!
s{%fi*
6(5c7R#
public Utility() }`@?X"r
{ ks^|>
0- Yeu5A
$pBr &,
} ^k9rDn/AW
\1khyF'
//线程睡眠 ]*h&hsS0
public static void sleep(int nSecond) |x[$3R1@
{ r2)pAiTM*
try{ bn|DRy
Thread.sleep(nSecond); A@{ !:_55
} ][N) 2_^M
catch(Exception e) /op/g]O}
{ RQJ9MGw
e.printStackTrace (); G32_FQ$b
} n=SzF(S[M
} :6sGX p
'XME?H:q a
//日志 z7$}#)Z7
public static void log(String sMsg) 6 cr^<]v!
{ Uc>LFX& -B
System.err.println(sMsg); o[H\{a>
} |<2JQ[]
iqlVlm>E
IM|Se4;x
public static void log(int sMsg) @%keTTZ
{ O^Dc&w
System.err.println(sMsg); m>+A*M8
} Bzwx0c2VY8
} qIUC2,&g
zVn*!c
GHqBnE{B
/* vzQyE0T/
**TestMethod.java @YbZ8Uc
*/ Hm<M@M$aG
package NetFox; -<12~HKK::
-{r!M(47
,$SkaTBe
public class TestMethod { mKMGdN~
jFS'I*1+
se"um5N-
public TestMethod() (h%|;9tF
{ ///xx/weblogic60b2_win.exe *%]+sU
try{ iu+zw[f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QDl)92z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %j!z\pa
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?\l!]vu*
fileFetch.start(); ^S:cNRSW"
} <(ubZ
catch(Exception e){e.printStackTrace ();} sd]0Hx[
{m>~`
sL;z"N@PK
} SIJ# ?0,
V&$ J;
t PAt?
public static void main(String[] args) G<Th<JF)Q
{ k^~@9F5k
new TestMethod(); gA|!$EAM
} ~&vA_/M
} `mQP{od?"?
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