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)); B(h%>mT[
} TdWatvY5p
for(int i=0;i<nEndPos.length-1;i++) ,@4~:OY
{ \RDS~u\d
nEndPos = nStartPos[i+1]; C4^o= 6{
} 6#DDMP8;I
nEndPos[nEndPos.length-1] = nFileLength; X{G&r$
} {<1 ]cP
} y$C\b\hM
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u</LgOP`-
//启动子线程 -oR P ZtW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R /0zB
for(int i=0;i<nStartPos.length;i++) ZF~@a+o
{ ,37\8y?o\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5VR=D\j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qz6@'1
nStartPos,nEndPos,i); K#!c<Li#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .bvEE
fileSplitterFetch.start(); dcbE<W#ss
} &Y3r'"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ap|$8G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); aT"0tn^LO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^(on"3sG
nEndPos = " + nFileLength); !b4v}70,
// fileSplitterFetch[nPos.length-1].start(); ~duF2m 72
!rZ r:@
5l[&-:(Lh
//等待子线程结束 ,Vr-E
//int count = 0; zqt{oN_
//是否结束while循环 xfK@tLEZ-1
boolean breakWhile = false; ptMDhMVW
e-Ma8+X\
iininITOS{
while(!bStop) ykat0iqo
{ ;Qq<5I"y
write_nPos(); m;@8z[ ^5
Utility.sleep(500); f1,VbuS9I
breakWhile = true; BOdd~f%&tn
^2)<H7p
xh|<`>5
for(int i=0;i<nStartPos.length;i++) &UfP8GE9
{ RBOg;EJ
if(!fileSplitterFetch.bDownOver) iV2v<ap.n
{ !\Vc#dslt
breakWhile = false; &\$~
break; )wyC8`&-
} -"uOh,G}
} 7*\CfqrU
if(breakWhile) n5>OZ3 E@
break; HP2J`>oo
!hWS%m@
IF'Tj`yD
//count++; o'J^kd`
//if(count>4) *!m(oP
// siteStop(); u1;sH{YK>
} JpE7"Z"~MS
hAU@}"=G
34<k)0sO
System.err.println("文件下载结束！"); y/>IF|aX
} \zLKSJ]
catch(Exception e){e.printStackTrace ();} [PX%p;"D
} nAaY5s0D
xVN(It7g
buKSZ
//获得文件长度 ]e6$ ={
public long getFileSize() Q4ZKgcC
{ @id!F<+%oD
int nFileLength = -1; H;{IOBo
try{ IN7Cpg~9%
URL url = new URL(siteInfoBean.getSSiteURL()); B]u!BBjC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,{2= nb[
httpConnection.setRequestProperty("User-Agent","NetFox"); -an~&C5\
!U=o<)I
l/-qVAd!q
int responseCode=httpConnection.getResponseCode(); wQX18aF/#d
if(responseCode>=400) t$z 5m<8
{ pS+hE4D
processErrorCode(responseCode); Te2C<c
return -2; //-2 represent access is error (tvfF0~
} (lg~}Jwq
N$N7aE$
%E2V$l0
String sHeader; d.$0X/0
Q8D#kAYw
_E2W%N
for(int i=1;;i++) {PKf]m
{ rT_J6F5J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rT(b t~Z
//Utility.log(in.readLine()); EGVS8YP>h
sHeader=httpConnection.getHeaderFieldKey(i); LK+67Y{25
if(sHeader!=null) @{{6Nd5
{ >S>B tRl
if(sHeader.equals("Content-Length")) bF'Jm*f
{ DT3"uJTt
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~,7Tj
break; %>!W+rO,
} KAg-M#
} 9AJ"C7
else K57u87=*X?
break; MU:q`DRr
} =[,EFkU?B
} MdhD "Q
catch(IOException e){e.printStackTrace ();} Q zp!)i
catch(Exception e){e.printStackTrace ();} RQ;w$I\
$Y M(NC
9Ed=`c
Utility.log(nFileLength); k)R~o b
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*Hz]<b?
return nFileLength; fd$nAE
} upnX7as
,\T7{=ZG\!
A1n4R
//保存下载信息（文件指针位置） _+,>NJ
private void write_nPos() i0F6eqe=J
{ n0Qp:_2z
try{ &v#pS!UOj
output = new DataOutputStream(new FileOutputStream(tmpFile)); f2u4*X E\
output.writeInt(nStartPos.length); g@Pq<
for(int i=0;i<nStartPos.length;i++) Y`."=8R~
{ P9W?sPnC5
// output.writeLong(nPos); t;`ULp~&
output.writeLong(fileSplitterFetch.nStartPos); /ke[nr
output.writeLong(fileSplitterFetch.nEndPos); Z7>Nd$E{
} E24j(>
output.close(); i.{.koH<
} Rn)fwGC
catch(IOException e){e.printStackTrace ();} OIDP#K
catch(Exception e){e.printStackTrace ();} rl,i,1t
} _nM 7SK
Hk'R!X
3YG%YhevO
//读取保存的下载信息（文件指针位置） (8~D^N6Z
private void read_nPos() a"l\_D'.K8
{ UF$O@l
try{ "7eL&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g7{:F\S
int nCount = input.readInt(); dQ_hlx!J
nStartPos = new long[nCount]; (|>rDk;
nEndPos = new long[nCount]; izzX$O[=:
for(int i=0;i<nStartPos.length;i++) Tgl>
{ R90#T6^
nStartPos = input.readLong(); V|~o`(]
nEndPos = input.readLong(); @}2EEo#
} 51tZ:-1!
input.close(); |{JI=$
} Shv$"x:W
catch(IOException e){e.printStackTrace ();} OZA^L;#>
catch(Exception e){e.printStackTrace ();} WrS>^\:
} 6AoKuT;
IJVzF1vC
[] el4.J,
private void processErrorCode(int nErrorCode) lF t^dl^
{ "dT"6,
System.err.println("Error Code : " + nErrorCode); 10)RLh|+
} {T-^xwc
'rTJ*1i
GaV}@Q
//停止文件下载 hxMV?\MYj
public void siteStop() &;~?\>?I
{ i[ >U#5
bStop = true; ^C92R"*Qu
for(int i=0;i<nStartPos.length;i++) 3 NFo=Z8
fileSplitterFetch.splitterStop(); y` {|D*
bDm7$ (
*Q)-"]O(k
} " %qr*|
} :K5?&kT
//负责部分文件的抓取 D)Ep!`Q
**FileSplitterFetch.java )U7fPKQ
*/ 1wm`a
package NetFox; /='Q-`?9
hC9EL= A
?z2!?
import java.io.*; BMqr YW
import java.net.*; 7t1as.
/]U;7)
(G/(w%#7_
public class FileSplitterFetch extends Thread { &H P g>
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gVe]?Jva`
String sURL; //File URL E-($Xc
long nStartPos; //File Snippet Start Position <EQaYZY=
long nEndPos; //File Snippet End Position z;y{QO
int nThreadID; //Thread's ID s;..a&C'
boolean bDownOver = false; //Downing is over R7K`9 c1f6
boolean bStop = false; //Stop identical Fq_>}k@fI
FileAccessI fileAccessI = null; //File Access interface ,LlYRj 5
uE<8L(*B
^B%c3U$o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 00{a}@n
{ B:Ft(,
this.sURL = sURL; W#E(?M[r
this.nStartPos = nStart; h"/'H)G7_&
this.nEndPos = nEnd; 2W`WOBz
nThreadID = id; Xs# _AX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JWYe~
} cy)-Rfg
![nL/
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public void run() QqRF?%7q"q
{ cTS.yN({G
while(nStartPos < nEndPos && !bStop) \#WWJh"W
{ : p)R,('g
ij!],
D4C:%D
try{ 7qZC+x6_L
URL url = new URL(sURL); -FI)o`AE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }2;iIw`
httpConnection.setRequestProperty("User-Agent","NetFox"); <:NahxIlu
String sProperty = "bytes="+nStartPos+"-"; :WX OD
httpConnection.setRequestProperty("RANGE",sProperty); u|T]Ne
Utility.log(sProperty); /zb/am1#
(z.n9lkfi
^)I}#
InputStream input = httpConnection.getInputStream(); G;iH.rCH
//logResponseHead(httpConnection); KO%$
W$2\GPJt
?Z_T3/ f
byte[] b = new byte[1024]; Kh[l};/F
int nRead; F\^8k/0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SDV#p];u
{ LMx/0
nStartPos += fileAccessI.write(b,0,nRead); l2:-).7xt
//if(nThreadID == 1) 3;VH'hh_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,msP(*qoI
} 1G"ohosmF
*S"RU~1_
Jwfb%Xge~
Utility.log("Thread " + nThreadID + " is over!"); %8h=_(X\7
bDownOver = true; <7SE|
//nPos = fileAccessI.write (b,0,nRead); /e[m;+9^&
} zi3v,Kq
catch(Exception e){e.printStackTrace ();} iETUBZ
} X7AxI\h
} WcoA)we
M_Q`9
ZSW@,Ti
//打印回应的头信息 P+CdqOL
public void logResponseHead(HttpURLConnection con) Maq`Or|4
{ L+p}%!g
for(int i=1;;i++) Q{?\qCrrYl
{ dNNXMQ0"
String header=con.getHeaderFieldKey(i); [@5cYeW3.
if(header!=null) `2LmLFkb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2G$px
Utility.log(header+" : "+con.getHeaderField(header)); fP5i3[T
else 5>+@.hPX
break; TfT^.p*
} ?jUgDwc(w
} }$ySZa9
.r{t&HO;Y
M2p|&Z%
public void splitterStop() 8<mloM-4
{ YY:{/0?
bStop = true; yn$1nt4
} iE HWD.u
xw_klHL-o
pe0ax-Zv
} }/&Zo=Q$
:$k1I-^R
]'[:QGr
/* pfHjs3A=
**FileAccess.java y6tqemz
*//文件访问(定位，写) yP"}(!~m
package NetFox; |;xEKnF
import java.io.*; JbL3/h]
&9)/"
i%.k{MY
public class FileAccessI implements Serializable{ bf+C=A)s0
ymqv@Byi8A
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %K')_NS@
RandomAccessFile oSavedFile; n44 T4q
long nPos; EyVu-4L:#
m BFNg3_
kP+,x H)1
public FileAccessI() throws IOException /;+\6(+X
{ 3@\/5I xn
this("",0); e)B1)c8s
} B>>_t2IU
`|>]P"9yp
>'W,8F
public FileAccessI(String sName,long nPos) throws IOException "{qnm+G
{ ,$/Ld76U
oSavedFile = new RandomAccessFile(sName,"rw"); GiX3c^V"1
this.nPos = nPos; MGMJeqvr
oSavedFile.seek(nPos); {*F =&D
} JxwKTFU'3O
!J<Xel{
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public synchronized int write(byte[] b,int nStart,int nLen) J&fIWZ
{ 4-SU\_
int n = -1; k<Gmb~Tg1
try{ i0/QfB%O
oSavedFile.write(b,nStart,nLen); b way+lh
n = nLen; <!FcQVH+L
} ]s0wJD=
catch(IOException e) zps=~|
{ /7\q#qIm:
e.printStackTrace (); xok T
} f4\$<g/~
9ghzK?Yc
X"d"a={]
return n; y3b"'-%
} m4oj1h_4
]tT=jN&(
y[85eM
} qQ^CSn98J
B-w`mcqp$
u9KT_` )
/* G^nG^HTo5
**SiteInfoBean.java ^gx~{9`RR
*/ xBc|rqge
package NetFox; -O?HfQ
CF','gPnc
N8At N\e
public class SiteInfoBean { IMbF]6%p(
5o 5DG
=cS5f#0
private String sSiteURL; //Site's URL "GZ}+K*GG
private String sFilePath; //Saved File's Path %V]v,
private String sFileName; //Saved File's Name h M7 SGEV
private int nSplitter; //Count of Splited Downloading File 9#P~cW?
y7:f^4
K/Yeh<_&
public SiteInfoBean() ![ce }
{//nSplitter的缺省值为5 y[.lfW?)
//default value of nSplitter is 5 EGqu-WBS
this("","","",5); z-kv{y*Hu
} C=r`\W
X41Qkf{
<a$!S
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N}%AUm/L
{ *j]Bo,AC
sSiteURL= sURL; zn^7#$fC
sFilePath = sPath; 7L&,Na
sFileName = sName; 0]*W0#{Zj
this.nSplitter = nSpiltter; $t^Td<
y `FZ 0FI
Q njK<}M9
} T^#d;A
1aS:bFi`
nlhv
public String getSSiteURL() WO9vOS>
{ OAs>F"
return sSiteURL; 3bezYk
} "]G'^
2;>uP#1]
h%u!UHA
public void setSSiteURL(String value) +JC"@
{ `3ha~+Goo!
sSiteURL = value; 9-{+U,3)
} d9S?dx
w=(dJ(7gu
BNjMq
public String getSFilePath() H.XyNtJ
{ "}1cQ|0a
return sFilePath; km9#lK
} /KC^x=Xv:
BNE:,I*&
kZG;\
public void setSFilePath(String value) hQe78y
{ G)[gLD{g?
sFilePath = value; xLFMC?I
} $rk=#;6]v;
!ck~4~J
D:j5/ *
public String getSFileName() qzORv
{ --"5yGOL
return sFileName; zfI{cMn'J
} YI*H]V%w
G$'UK
9]ZfSn)
public void setSFileName(String value) (-0d@eqw
{ q({-C
sFileName = value; Tf!6N<dRXR
} VByA6^JR
;Dp*.YJ
CfS;F
public int getNSplitter() ;PG= 3j_
{ vv2[t
return nSplitter; _8y4U[L
} .p=J_%K}0x
0[d*Z
AU)\ lyB
public void setNSplitter(int nCount) ! jApV
{ QR(;a:
nSplitter = nCount; hP WP6;Z
} S2|pn\0V
} V\L%*6O
&$2d=q8mh
zBq&/?
/* A7#nBHwxZ
**Utility.java Y=Ic<WHR
*/ ^fO9oPM|
package NetFox; KwaxNb5
5`e;l$ M`
](n)bF+ym
public class Utility { !PeSnO
qhTVsZ:{C
_}JMBIq$
public Utility() TYR \K
{ wBw(T1VN
Iy;"ht6
PU%f`)
} jHE^d<=O^
z#`Qfvu6Hi
//线程睡眠 tUOY`]0
public static void sleep(int nSecond) Nc[N 11?O
{ Zw{?^6;cS
try{ GNuIcy
Thread.sleep(nSecond); j-"34
} TUwX4X6m
catch(Exception e) N8kNi4$mp=
{ V'dw=W17V
e.printStackTrace (); :eL[nyQr
} =~W=}
} ci2Z_JA+
[FF}HWf
//日志 Z 1wtOL
public static void log(String sMsg) 3Ur_?PM+C
{ n!SHExBp
System.err.println(sMsg); *]R5bj.!o
} `Xeiz'~f8
=E!Y f#p+q
5wAKA`p"z
public static void log(int sMsg) ! N!pvK;
{ r: >RH,
System.err.println(sMsg); mqsAYzG
} ,H.5TQ#
} h0dZr-c
[742s]j
Nr*X1lJ6
/* w?8\9\ ;?
**TestMethod.java A1Uy|Dl
*/ B1U!*yzG6
package NetFox; GNrRc3dr$
l. cp[
cvT@`1
public class TestMethod { H n]( )/
?tqJkL#
uF}B:53A
public TestMethod() b3 =Z~iLv
{ ///xx/weblogic60b2_win.exe [MbbL
try{ +kE~OdZG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (G{S*+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2cIbX
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1\aTA,
fileFetch.start(); dXM8iP
} PrfG
catch(Exception e){e.printStackTrace ();} 0nkC%j
gE^pOn
3 4%B0
} IqepR >5t
PXtF#,roP
3XDU(#
public static void main(String[] args) }hg2}g99
{ O8" t.W
new TestMethod(); o%;ly
} ~a_X 7
} T"X]@9g^-
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