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)); h;0S%ZC
} /soKucN"h
for(int i=0;i<nEndPos.length-1;i++) +$Rt+S BD
{ )(@Hd
nEndPos = nStartPos[i+1]; 7hcNf,
} /Ju;MeE9
nEndPos[nEndPos.length-1] = nFileLength; t2"FXTAq
} y a_<^O 9
} wiBVuj#
S<J}[I7V
y\x+
//启动子线程 /:FOPPs
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .c$316
for(int i=0;i<nStartPos.length;i++) }-@`9(o`)
{ iya"ky~H
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *<!oHEwkN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !Xph_SQ!B=
nStartPos,nEndPos,i); B2O}1.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); plZ>03(6Q
fileSplitterFetch.start(); CJ++?hB]X
} ki)#d' }
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w[ ~#av9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); uDZT_c'Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y TDNNK
nEndPos = " + nFileLength); k]I0o)+O.
// fileSplitterFetch[nPos.length-1].start(); RH|XxH*
>i6yl5s
9WR6!.y#f
//等待子线程结束 3Gip<\$v
//int count = 0; fS`$'BQ
//是否结束while循环 gatB QwJb9
boolean breakWhile = false; 'R:"5d
NG6& :4!
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while(!bStop) Kx%Sku<F'
{ 2j&AiD
write_nPos(); cSm%s
Utility.sleep(500); Nj 00W1
breakWhile = true; (V HL{rj
>orK';r<
]i)j3WDz]
for(int i=0;i<nStartPos.length;i++) ?pzaG{
{ 5;{H&O9Q
if(!fileSplitterFetch.bDownOver) @n": w2^B
{ "T- `$'9
breakWhile = false; piZJJYv t
break; Zg.&V
} c[ ]4n
} QMpoa5ZQG
if(breakWhile) 'Un" rts
break; )[|3ZP`
E)fglYWs2
{qa Aq%'
//count++; @#-q^}3
//if(count>4) <(-hx+^
// siteStop(); Vkc#7W(
} w/K_B:s
aVd,xl
:]1TGfS
System.err.println("文件下载结束！"); ziCHjqT
} ,YMp<C
catch(Exception e){e.printStackTrace ();} aT$9;
} _zwUE
]:~OG@(
uF3qD|I\
//获得文件长度 t0T"@t#c
public long getFileSize() m RO~aD!N
{ x a06i#
int nFileLength = -1; (#E.`e1#6
try{ smDw<slC
URL url = new URL(siteInfoBean.getSSiteURL()); u5%7}<nNi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5EfS^MRf\n
httpConnection.setRequestProperty("User-Agent","NetFox"); G@Z?&"
7?%k7f
v*[.a#1^
int responseCode=httpConnection.getResponseCode(); AD<q%pu&H?
if(responseCode>=400) X<%Q"2hW
{ mFZ?hOyP.
processErrorCode(responseCode); ;{%\9nS
return -2; //-2 represent access is error {b
} ~Wa6J4B{K
_n` a`2C|m
i|m3mcI%2
String sHeader; 6Avw-}.7>
Q(oN/y3,
7[}xP#Z
for(int i=1;;i++) KPj\-g'A
{ " _ka<R..
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;hjwD
//Utility.log(in.readLine()); vt9)pMs
sHeader=httpConnection.getHeaderFieldKey(i); e;[F\ov%
if(sHeader!=null) L-k@-)98
{ ynhmMy%
if(sHeader.equals("Content-Length")) EL9]QI
{ B,=H@[Fj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /x1![$oC0
break; &mtJRfnu
} HI11Jl}{
} =^5Alba/
else KW^7H
break; O|M{-)
} BjzPz
} .ODR]7{
catch(IOException e){e.printStackTrace ();} q*7VqB
catch(Exception e){e.printStackTrace ();} 5w@4:$=I
c>)Yt^q&K
d>t<_}
Utility.log(nFileLength); I]EbodAyZ,
07^iP>?
ptZ <ow&
return nFileLength; ?TKRjgW`@_
} yLQ*"sw\
x-?Sn' m
Cy=Hy@C
//保存下载信息（文件指针位置） rMhB9zB1
private void write_nPos() PU1Qsb5
{ trp0V4b8
try{ ]n~ilS.rkl
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~"kb7Fxp
output.writeInt(nStartPos.length); n*{sTT
for(int i=0;i<nStartPos.length;i++) <t \H^H!
{ :1bWVM)
// output.writeLong(nPos); DRi<6Ob
output.writeLong(fileSplitterFetch.nStartPos); K$E3QVa
output.writeLong(fileSplitterFetch.nEndPos); Nqa&_5"
} q;][5
output.close(); 4QIX19{"
} Us0EG\Y
catch(IOException e){e.printStackTrace ();} Z Z:}AQ
catch(Exception e){e.printStackTrace ();} ^8AXxE
} OD6\Mr2=
|* ;B
ub\MlSr
//读取保存的下载信息（文件指针位置） z-.+x3&o @
private void read_nPos() 6U R2IxbE
{ 9vvx*rD
try{ 5Ezw ~hn
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @3C>BLI8+
int nCount = input.readInt(); =t H:,SH
nStartPos = new long[nCount]; 5?F__Hx*2
nEndPos = new long[nCount]; jGpN,/VQa
for(int i=0;i<nStartPos.length;i++) Tw;3_Lj
{ zPjHsulK
nStartPos = input.readLong(); N%*5T[.
nEndPos = input.readLong(); j+uLV{~g6
} P<a)25be/
input.close(); jT]0WS-b
} :6Lx@
catch(IOException e){e.printStackTrace ();} Yd=>K HVD
catch(Exception e){e.printStackTrace ();} sEGO2xeI
} [8*jw'W|[
^!<BQP7
P>NF.BCq
private void processErrorCode(int nErrorCode) g9Xu@N;bL
{ IV\'e}
System.err.println("Error Code : " + nErrorCode); %~2YE
} U$WxHYo
K|hjEQRv
q$B>|y U
//停止文件下载 EkjN{$*
public void siteStop() 'z%o16F)L
{ <YhB8W9 P
bStop = true; ZL&g_jC
for(int i=0;i<nStartPos.length;i++) 1Y7Eajt-5
fileSplitterFetch.splitterStop(); V4'YWdTi
lrIS{MJ+-
&)AVzN+*h
} zGAq-<
} _0]S69lp
//负责部分文件的抓取 #AL=f'2=f
**FileSplitterFetch.java DkvF5c&
*/ t>`asL
package NetFox; R|(q
,0~n3G
Tk:h@F|B.|
import java.io.*; `\#B18eU
import java.net.*; `OXpU,Z 6U
j/f?"VEr
[d1mLJAR
public class FileSplitterFetch extends Thread { hPUYyjXPB
"NXB$a!:
y)W@{@{kl
String sURL; //File URL %'s>QF]'
long nStartPos; //File Snippet Start Position -y8`yHb_
long nEndPos; //File Snippet End Position =E.t`x=
int nThreadID; //Thread's ID ]%wVHC
boolean bDownOver = false; //Downing is over m g4nrr\
boolean bStop = false; //Stop identical V9{]OV%
FileAccessI fileAccessI = null; //File Access interface S~;4*7+?:
1^7hf;|#g
w&o&jAb-M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $Bs {u=+w
{ 7b;I+q
this.sURL = sURL; ,+meT`'vn
this.nStartPos = nStart; 7Z\--=;|[:
this.nEndPos = nEnd; ,y 2$cO_>
nThreadID = id; 7BK0}sxO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *KV0%)}sbL
} s/q7.y7n{
iS WU'K
R3;Tk^5A
public void run() b\$}>O
{ Rv$[)`&T
while(nStartPos < nEndPos && !bStop) X[PZg{
{ ^=RffrlZU
=u2l.CX
Y&d00
try{ WJkZ!O$"j
URL url = new URL(sURL); E[@ u 3i8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $RIecv<e_
httpConnection.setRequestProperty("User-Agent","NetFox"); <SgM@0m
String sProperty = "bytes="+nStartPos+"-"; `_`QxM
httpConnection.setRequestProperty("RANGE",sProperty); `.FF!P:{C*
Utility.log(sProperty); \n8]M\<
T|7}EAR=b
>0ph9$
InputStream input = httpConnection.getInputStream(); Mn2QZp4
//logResponseHead(httpConnection); j3{I /m
s;S?;(QI
XWS%zLaK
byte[] b = new byte[1024]; uW@oyZUj
int nRead; :(!`/#6H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w$z}r
{ mKL<<L[
nStartPos += fileAccessI.write(b,0,nRead); Li/O
//if(nThreadID == 1) rV R1wsaL
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Mc09ES
} 5Iy;oZ
}Qip&IN
wsIW |@
Utility.log("Thread " + nThreadID + " is over!"); >VP=MbN
bDownOver = true; ^;Y|3)vvB
//nPos = fileAccessI.write (b,0,nRead); E*V`":efS
} s.N7qO^:E
catch(Exception e){e.printStackTrace ();} aE&,]'6
} m#PY,y
} Tx|Ir+f6L
KxYwJ
w+#C-&z
//打印回应的头信息 6:Ch^c+IZ
public void logResponseHead(HttpURLConnection con) XQ9O$ ~q
{ )}D'<^=#T
for(int i=1;;i++) 8\^}~s$$A
{ R?~Yp?B^
String header=con.getHeaderFieldKey(i); u37'~&o{U
if(header!=null) ;aI[=?<x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6*B19+-
Utility.log(header+" : "+con.getHeaderField(header)); ?s\:hNNY
else 2N~Fg^xB
break; m?pstuUK(
} ewa wL"
} -(bXSBs#
7'Zky2F
-+ SF
public void splitterStop() - }7e:!.
{ ej4W{IN~:
bStop = true; Z:,U]Z(
} 5p<ItU$pnL
qq) rd
hAYTj0GZ
} x }\64
k7?N ?7w
'Jt]7;04p
/* ^?cz,N~
**FileAccess.java lE;Ewg
*//文件访问(定位，写) k9 "[H'
package NetFox; uD1e!oU
import java.io.*; D7lK30
WHsgjvh"
tBq nfv
public class FileAccessI implements Serializable{ pm*xb]8y
#MX'^RZ>2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y.e^hRKb
RandomAccessFile oSavedFile; o<<xY<
long nPos; 1rv)&tKs
])|d"[ur=
//T>G_1
public FileAccessI() throws IOException M9V q -U18
{ rR9|6l 3
this("",0); mef<=5t
} [5zx17'
Izhee%c
,sA[)wP{
public FileAccessI(String sName,long nPos) throws IOException G;v8$)Zj
{ #33fGmd[
oSavedFile = new RandomAccessFile(sName,"rw"); jhXkSj
this.nPos = nPos; Q<h-FW8z
oSavedFile.seek(nPos); WF1px%
} 8P^ITL z%
Rv#]I#O
E~%jX }/
public synchronized int write(byte[] b,int nStart,int nLen) tw^,G(
{ :`-,Lbg
int n = -1; u.mJQDTH
try{ jNLw=
oSavedFile.write(b,nStart,nLen); )~+E[|
n = nLen; +=q$x Ia
} Xf02"PXC
catch(IOException e) : >6F+XZ
{ b7NM#Hb
e.printStackTrace (); &y3OR1_Sm*
} 0~ZFv Wv
X9p.gXF
9z}uc@#D=m
return n; KNS.Nw7
} jX3,c%aQ5e
*of3:w
9Wnn'T@Tl
} +?u~APjNN
q#vQv5
RA KFU
/* .q `Hjmg<
**SiteInfoBean.java Xe<sJ.&Wf
*/ ]$Yvj!K*Q
package NetFox; Fs{x(_LOr
q;<h[b?
_CW(PsfY
public class SiteInfoBean { A*2 bA
_AQb6Nb
\^ZlG.
private String sSiteURL; //Site's URL P%{^i]
private String sFilePath; //Saved File's Path 4a'N>eDR
private String sFileName; //Saved File's Name r<K(jG[:{f
private int nSplitter; //Count of Splited Downloading File GliwY_
k.uMp<)D
zaah^.MA|
public SiteInfoBean() MYla OT
{//nSplitter的缺省值为5 5]n[]FW
//default value of nSplitter is 5 V}dJ.I /#
this("","","",5); FrTi+& <
} AWP"b?^G|
k`0>36
}emN9Rj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pPcTrN'
{ -i)ZQCE
sSiteURL= sURL; ny`#%Vs
sFilePath = sPath; 0BIy>wy:
sFileName = sName; ;.TRWn#
this.nSplitter = nSpiltter; Q$HG
k Mu8"Az
*^f<W6xc
} lTd #bN
x7~r,x(xM
VY~yg*
public String getSSiteURL() +6';1Nb@
{ &K.?p2$X
return sSiteURL; (vb SM}P
} }oL'8-y
~ ip,Nl
S-k8jm
public void setSSiteURL(String value) #a<Gxj
{ VH+%a<v"
sSiteURL = value; oW<5|FaN
} 9\/xOwR
rcMwFE?|xq
+n#V[~~8AI
public String getSFilePath() $e*ce94
{ m|{3),#V
return sFilePath; }HY-uQ%@g
} w+yC)Rmz
F)W:
_>| =L W@7
public void setSFilePath(String value) R~)\3] "2m
{ @7?#Y|`
sFilePath = value; DpUbzr41+k
} <4P4u*/o
E=>FjCsu<-
G5CI<KRK#
public String getSFileName() 1XD,uoxB
{ @>p<3_Y1
return sFileName; j!]YNH@
} fZ*+2T>
vJ'2@f$
CCL
public void setSFileName(String value) QKr,g
{ ^~3SSLS4"
sFileName = value; K?BOvDW"`
} B]uc<`f
k~jP'aD
h"_MA_]~
public int getNSplitter() dHv68*^\'
{ =~=*&I4Dp
return nSplitter; >[_f3;P
} d4?Mi2/jF
22.8PO0
Bs O+NP
public void setNSplitter(int nCount) wM2*#
{ K%^V?NP*{Z
nSplitter = nCount; %O!v"Xh
} %`&2+\`
} ,M^P!
l]8D7(g
m+lvl
/* UE$UR#T'w
**Utility.java Q0&H#xgt
*/ cVv;Jn
package NetFox; p$PKa.Y3
X)7x<?DAy
0l-Ef1
public class Utility { {\c(ls{
J2'Nd'
WJ4li@T7V
public Utility() /f|X(docI
{ [3{W^WSOz
]Bjyi[#bg
XpBj%e:
} PfC!lI BU
z7Q?D^miy
//线程睡眠 NhaI<J
public static void sleep(int nSecond) NiU2@zgl
{ ]%?YZn<{
try{ G>1eFBh }
Thread.sleep(nSecond); FW/W%^
} STxKE %l
catch(Exception e) 9J9)AV
{ fjs [f'L
e.printStackTrace (); f"qga/
} 6WU(%
} SVO3821
>hk=VyU;
//日志 QA5QweL
public static void log(String sMsg) HN&Z2v
{ FRg^c kb"
System.err.println(sMsg); l}]t~!X=
} >rJnayLF
S$Q8>u6Wk
v?& -xH-S
public static void log(int sMsg) M;p em<
{ IHJ=i-
System.err.println(sMsg); oAPb*;}
} H\qC["
} YN!>}
0},PJ$8x
[&&1j@LQ*
/* m0cP(
**TestMethod.java rzh#CnL3
*/ !+L/Khw/C
package NetFox; ]y,==1To
rld67'KcE
`eIenA
public class TestMethod { rmE"rf
@>E2?CV
2ioQb`=
public TestMethod() \Dd-Xn_b
{ ///xx/weblogic60b2_win.exe }T%}wdj
try{ 4*e0 hWp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~ ; -! n;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1#0{@35
SiteFileFetch fileFetch = new SiteFileFetch(bean); ++V=s\d7
fileFetch.start(); 0IfKJ*]M
} XI22+@d6
catch(Exception e){e.printStackTrace ();} ]K/DY Do-
],RdySN&
K)\M5id]
} dVsE^jsL
$D}{]MN.
Mi/&f
public static void main(String[] args) =u+d_'P7-R
{ 2UFv9
new TestMethod(); )e a:Q?
} (Nx;0"5IX
} 49w=XJ
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