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)); akzKX}
} c]NZGn*
for(int i=0;i<nEndPos.length-1;i++) 1cD
{ ~)*uJ wW/a
nEndPos = nStartPos[i+1]; ] -%B4lT
} ?@7Reh\
nEndPos[nEndPos.length-1] = nFileLength; i<*W,D6
} meZZQ:eSl
} c9Q_Qr0'
.gY=<bG/fA
2:&L|;
//启动子线程 xXCsJ9]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ne%(`XY{Q]
for(int i=0;i<nStartPos.length;i++) 0F6~S
{ P?+ VR=t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r%%@~ \z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @ssT$#)$!
nStartPos,nEndPos,i); ]>[0DX]j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j+Q+.39s-~
fileSplitterFetch.start(); XQZiJ %'
} &3:<WU:U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q}#xfrprF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y<PQ$D)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zA|)9Dq
nEndPos = " + nFileLength); 6 2t9SY
// fileSplitterFetch[nPos.length-1].start(); !J[!i"e
3\K;y>NK
e8{!Kjiz
//等待子线程结束 oE)xL%*
//int count = 0; ;#=y5Q4
//是否结束while循环 '`j MNKn\
boolean breakWhile = false; OV`li#H
J:G{
W&7(
while(!bStop) qUk-BG8^
{ }O2P>Z?V
write_nPos(); p ^Y2A
Utility.sleep(500); De<i 8/^=
breakWhile = true; GjbOc
Kf`/ Gc!
[Xww`OUsh
for(int i=0;i<nStartPos.length;i++) 3e1%G#fu
{ [^gb6W9Y
if(!fileSplitterFetch.bDownOver) o90[,
{ N'Vj& DWC
breakWhile = false; r`e6B!p
break; m,&2s-v
} 1^2]~R9,9
} J7@Q;gcl:
if(breakWhile) d3NER}f4V
break; %2'Y@AX`
Qe`Nb4xf
b^"mQ
//count++; qyjVB/ko
//if(count>4) g|M>C:ZT
// siteStop(); q siV
} z&z5EtFUTh
,r;E[k@
p]jG ,S
System.err.println("文件下载结束！"); K4b2)8
} @{ L|&Mk!
catch(Exception e){e.printStackTrace ();} bjq.nn<=
} o)8VJ\ &
kArF Gb2c
O;.DQ
//获得文件长度 " "S&zN
public long getFileSize() B5[As8Sa
{ M-(,*6Q
int nFileLength = -1; 1jd.tup
try{ ~J >Jd
URL url = new URL(siteInfoBean.getSSiteURL()); _)6r@fZ.p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r(<91~Ww
httpConnection.setRequestProperty("User-Agent","NetFox"); 3gv?rJV
r9p ((ir
I_|W'%N]
int responseCode=httpConnection.getResponseCode(); &_' evZ8
if(responseCode>=400) V!s#xXD}
{ n>,? V3ly
processErrorCode(responseCode); F(w<YU%6
return -2; //-2 represent access is error CKX3t:HP0
} d"S\j@
_p<wATv?7t
%&wi@ *#
String sHeader; :0p$r pJP
HC"yC;_
qAt#0
for(int i=1;;i++) CHDt^(oa!B
{ xu>grj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8v6AfTo%
//Utility.log(in.readLine()); pv^:G;
sHeader=httpConnection.getHeaderFieldKey(i); RY\0dv>
if(sHeader!=null) {ITxHt
{ f]2;s#cu
if(sHeader.equals("Content-Length")) f||S?ns_
{ EmyE%$*T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1w+)ne_&
break; gFXz:!A
} 31N5dIi,
} fn8|@)J
else w8F`RRHEE
break; 'fZ\uMdTx
} hJ?PV@xy
} XE#$|Z
catch(IOException e){e.printStackTrace ();} ycf)*0k
catch(Exception e){e.printStackTrace ();} )U{\c2b
hLT?aQLx
H%{k.#O
Utility.log(nFileLength); :bkmm,%O
7_J0[C!G
}/jWa|)f
return nFileLength; gI/(hp3ob
} {uxTgX
0JW =RW
u.}H)wt
//保存下载信息（文件指针位置） <(1[n pS&+
private void write_nPos() (Mw+SM3<
{ w,t !<i
try{ gO/\Yi
output = new DataOutputStream(new FileOutputStream(tmpFile)); QE721y
output.writeInt(nStartPos.length); k{bC3)'$#R
for(int i=0;i<nStartPos.length;i++) 0XI6gPo%
{ 9[[$5t`8
// output.writeLong(nPos); XJ1Bl
output.writeLong(fileSplitterFetch.nStartPos); ,M$h3B\;r
output.writeLong(fileSplitterFetch.nEndPos); FLIU}doc
} #Fkp6`Q$x
output.close(); <&tdyAT?&
} E0.o/3Gw6
catch(IOException e){e.printStackTrace ();} -*qoF(/U
catch(Exception e){e.printStackTrace ();} <KX+j,4
} Nl^uA
o* e'D7
DH)E9HL
//读取保存的下载信息（文件指针位置） (4/W)L$
private void read_nPos() s%G%s,d
{ 5=1Ml50
try{ V?~!Dp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |Z8Eu0RSb
int nCount = input.readInt(); (IIZvCek
nStartPos = new long[nCount]; &g]s@S|%
nEndPos = new long[nCount]; HE0m#
for(int i=0;i<nStartPos.length;i++) I/u>Gt
{ B?4Iu)bCxI
nStartPos = input.readLong(); 5>hXqNjP2
nEndPos = input.readLong(); @QE&D+NS
} VFKFO9
input.close(); D58RHgY[
} 6_K7!?YG7
catch(IOException e){e.printStackTrace ();} H%0WD_
catch(Exception e){e.printStackTrace ();} yi2F#o 'K
} 3CPSyF
Hxn#vAc
!t?5U_on
private void processErrorCode(int nErrorCode) |O;vWn'U2
{ ~.z82m
System.err.println("Error Code : " + nErrorCode); )"_&CYnd
} 7c8`D;A-K
y[GqV_~?Y
t+M'05-U2
//停止文件下载 ;O~%y'
public void siteStop() QY*F(S,\
{ M^G9t*I
bStop = true; 9U3.=J
for(int i=0;i<nStartPos.length;i++) <@c@`K
fileSplitterFetch.splitterStop(); g!Ui|]BI9
Bq,MTzxD
"*:?m{w5
} h<qi[d4X
} kV4L4yE
//负责部分文件的抓取 +}eK8>2
**FileSplitterFetch.java c=aZ[
*/ E&)o.l<h|
package NetFox; m ;wj|@cF
%CqG/ol
_|#P~Ft
import java.io.*; m= %KaRI
import java.net.*; +o35${
!Z0S@]C
)S}.QrG
public class FileSplitterFetch extends Thread { Q]OR0-6<.
WkV0,_(P
ft~QVe!
String sURL; //File URL 'r1X6?dJ
long nStartPos; //File Snippet Start Position RFq=`/>dG
long nEndPos; //File Snippet End Position X.ZG-TC
int nThreadID; //Thread's ID iO$ ?No
boolean bDownOver = false; //Downing is over [7 t
boolean bStop = false; //Stop identical C8=rsh
FileAccessI fileAccessI = null; //File Access interface /l8wb~vl
l~[ K.p&
7^1K4%IPl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t0Inf [um
{ O`Htdnu
this.sURL = sURL; SZ:R~4 A
this.nStartPos = nStart; $QwzL/a
this.nEndPos = nEnd; O2xqNQ`d
nThreadID = id; n^nQrRIp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (%G>TV
} _qH]OSo
@c}Gw;e
}N:QB}7'_
public void run() y,`q6(&
{ ygd*zy9
while(nStartPos < nEndPos && !bStop) b#n
{ U !%IC7@
Nh !U
4tSh.qBht
try{ \w-3Spk*
URL url = new URL(sURL); 9fCU+s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bNHsjx@
httpConnection.setRequestProperty("User-Agent","NetFox"); TQOJN
String sProperty = "bytes="+nStartPos+"-"; 2}_^~8
httpConnection.setRequestProperty("RANGE",sProperty); Sg13Dp@x
Utility.log(sProperty); 5!jt^i]O
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hMgk+4*
InputStream input = httpConnection.getInputStream(); y^D3}ds
//logResponseHead(httpConnection); pP%+@;
g_eR&kuh
lq?N>~PG
byte[] b = new byte[1024]; J ayax]u7J
int nRead; :u2tu60&MJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [a.(0YLr'w
{ YVk +zt~S
nStartPos += fileAccessI.write(b,0,nRead); sosIu
//if(nThreadID == 1) .!'rI7Kz'i
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Kr`.q:0GK
} ca[*#xiJ
VeH%E.:
.5tXwxad"
Utility.log("Thread " + nThreadID + " is over!"); W k"_lJ
bDownOver = true; |aj]]l[@S
//nPos = fileAccessI.write (b,0,nRead); H~:g=Zw
} V'9OGn2v
catch(Exception e){e.printStackTrace ();} slLTZ]
} xscR Bx
} I]~s{I(EK
ncpA\E;ff^
T,B%iZgCh
//打印回应的头信息 QRF:6bAxsL
public void logResponseHead(HttpURLConnection con) V1A7hRjxvG
{ S)"vyGv
for(int i=1;;i++) GT3}'`f B
{ m-qOyt
String header=con.getHeaderFieldKey(i); 6K >(n
if(header!=null) ^plP1c:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $GVf;M2*
Utility.log(header+" : "+con.getHeaderField(header)); @;[.#hK
else \P*%u
break; WK.,q>#
} nVGOhYn
} \_+Af`
7j"B-k#
fUJe{C<H
public void splitterStop() 5!6}g<z&L
{ f%REN3=5K
bStop = true; GB}X
} y;hco
vVo# nzeZ5
^(:na6C
} @d|]BqQ4jh
!DKl:8mx4
Y1BxRd?D
/* =g=Vv"B_
**FileAccess.java 1+-F3ROP
*//文件访问(定位，写) l%`~aVGJ
package NetFox; |~=4ZrcCP
import java.io.*; UQtG<W]<
b+BX >$
U"Z%_[*
public class FileAccessI implements Serializable{ `?T8NK
lPz5.(5'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zf^@f%R
RandomAccessFile oSavedFile; 6|1#Prj
long nPos; ~SEIIq
~$bQ;`,L
S7CD#Y[s
public FileAccessI() throws IOException 24Htr/lPCT
{ 1EHNg<J(
this("",0); w Qp{z
} UZE%!OWpeK
p+{*w7?8"[
y{nX 6
public FileAccessI(String sName,long nPos) throws IOException 9(BB>o54r
{ o2LUB)=R'
oSavedFile = new RandomAccessFile(sName,"rw"); <Q.-WV]Z
this.nPos = nPos; `=8G?3
oSavedFile.seek(nPos); U9RpHh`
} ~ o5h}OU"
`]<~lf
);^{;fLy%
public synchronized int write(byte[] b,int nStart,int nLen) VF9-&HuC
{ ||4++84{
int n = -1; y(Q.uYz*
try{ 3<6P^p=I
oSavedFile.write(b,nStart,nLen); (' i_Xe
n = nLen; 79U7<]-!
} d.NB@[?*
catch(IOException e) _\FA}d@N
{ y;HJ"5.Mw
e.printStackTrace (); 7JP.c@s
} Zg!E}B:z
55`cNZ
v=+>ids
return n; DFqVZ
} 3a,7lTUuB
hfQ^C6yR
wW^3/
} C#.d sl
B4# gT
Yc V*3`
/* 6j~'>w(F
**SiteInfoBean.java H3o Um1
*/ 7ZgFCK,8m,
package NetFox; z^9df(
9{{CNy p
o=doL{#
public class SiteInfoBean { YCB=RT]&`
3 jay V
?I#zcD)w
private String sSiteURL; //Site's URL [Uu!:SZ
private String sFilePath; //Saved File's Path *:V"C\`^n
private String sFileName; //Saved File's Name cX@72
private int nSplitter; //Count of Splited Downloading File gOA]..lh
"8`f x
Z9 tjo1X
public SiteInfoBean() KRP)y{~o
{//nSplitter的缺省值为5 Hk;) l3oB
//default value of nSplitter is 5 !8>tT
this("","","",5); [a1}r=6~
} YPsuG -is
81U(*6
Nv_"?er+y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) GvT'v0&+
{ w.H\j9E l
sSiteURL= sURL; gj Ue{cb5
sFilePath = sPath; $+a2CZs!
sFileName = sName; cwA+?:Ry}
this.nSplitter = nSpiltter; p[-buB]
EK}f-Xei
DvvjIYB~
} u-E*_%y
-|xyj2M
g4*]R>f
public String getSSiteURL() 20H$9M=}
{ vZpt}u
return sSiteURL; W%RjjLJ@
} Y$?<y
slMWk;fmD}
`ynD-_fTN
public void setSSiteURL(String value) Y:XxTa*
{ `l95I7
sSiteURL = value; skP2IMa75
} g4^df%)&
N!F ;!
t^qPQ;"=,
public String getSFilePath() Af>Ho"i
{ 3pKr {U92
return sFilePath; ?$xZ$zW
} 3YF*TxKx
KCkA4`IeM
v-@xO&<
public void setSFilePath(String value) CCZ]`*wJ
{ za20Y?)[
sFilePath = value; we&g9j'
} ,kKMUshBi
|JW-P`tL0
JY tM1d
public String getSFileName() Pz1[ b$%
{ v1Lu.JQC$
return sFileName; (s`yMUC+
} \f_YJit
6uf+,F
|PED8K:rU
public void setSFileName(String value) Ue<Y ~A
{ ~h{v^}
sFileName = value; 3N,!y
} uiIY,FL$
ApYri|^r
qE`
public int getNSplitter() 3g]Sp/
{ fhAK^@h
return nSplitter; L 59q\_|
} rSVU|O3m;
9+\3E4K
gs_nUgcA
public void setNSplitter(int nCount) r9@Q="J_)
{ GJY7vS^#
nSplitter = nCount; ?B2 T'}~
} ^\uj&K6l
} `}^_>
/CAi%UH,F
#eT{?_wM
/* &Q[Y&vNn
**Utility.java n^;:V8k
*/ F$FCfP7
package NetFox; 6XO%l0dC.
YoKY&i6r}
S/|'ggC
public class Utility { X#mppMU
dM(}1%2
lk6*?EJ
public Utility() SPxgIP;IR
{ F.b;O :
AoEG%nT
AopCxaJ`
} ui,#AZQ#{4
EF?@f{YY$n
//线程睡眠 EwcN$Ma
public static void sleep(int nSecond) PYl(~Vac
{ W,iSN}
try{ HKk;oG
Thread.sleep(nSecond); dD3I.?DY
} Y zXL8
catch(Exception e) 0SXWt? }
{ hgCeU+H
e.printStackTrace (); 0.-2FHc9L
} (DCC4%w"
} ?3"bu$@8
aU3 m{pE
//日志 "]ow1{
public static void log(String sMsg) -So&?3,\A@
{ '~3a(1@8
System.err.println(sMsg); :cmfy6h]
} O1Gd_wDC/i
SB1\SNB
@O<kjR<b
public static void log(int sMsg) xr)Rx{)3h
{ t,;1?W#
System.err.println(sMsg); zlmb_akJ
} 2yhtJ9/
} [EDw0e
|*0oz=
5rqjqfFa
/* cjf}yn
**TestMethod.java :Xv3< rS<
*/ mfO:#]K
package NetFox; zm}4=Kz}
N0h"EV[
q#-szZQ
public class TestMethod { \.A~>=:
MEbx{XC
W xyQA:3s
public TestMethod() ti)foam
{ ///xx/weblogic60b2_win.exe e*e}X&|(g
try{ 2Av3.u8%u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ud0%O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $WvI%r
SiteFileFetch fileFetch = new SiteFileFetch(bean); IBY3QG
fileFetch.start(); !JjB,1
} #F.;N<a
catch(Exception e){e.printStackTrace ();} >De\2gbJ
y@J]busU
kIV/o
} @6>R/]
I.j`h2
pr.Vfb
public static void main(String[] args) m,v"N%k,
{ G6xdGUM
new TestMethod(); *plsZ*Q8
} *TA${$K
} !mrB+<:
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