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)); l#u$w&
} xa#;<8 iV
for(int i=0;i<nEndPos.length-1;i++) EYWRTh
{ y,'M3GGl
nEndPos = nStartPos[i+1]; vYb.Ub+
} D*.U?
nEndPos[nEndPos.length-1] = nFileLength; 0Cd)w4C
} ?e( y/
} K",YAfJa
&iR3]FNI
:}(Aq;}X
//启动子线程 :_9MS0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &$$KC?!w
for(int i=0;i<nStartPos.length;i++) (%.[MilxPM
{ L~9Q7 6w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2$ m#)*\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %f3qCN
nStartPos,nEndPos,i); ]e`&py E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C#<b7iMg
fileSplitterFetch.start(); 8Ld{Xg
} SQ&nQzL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <&JK5$l<X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j#4 Iu&YJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5B6twn~[
nEndPos = " + nFileLength); \%&BK.t
// fileSplitterFetch[nPos.length-1].start(); ybk~m
t<=Ru*p
zv[$N,
//等待子线程结束 y2Eq-Ie
//int count = 0; 96G8B62
//是否结束while循环 n}0n!Pr^
boolean breakWhile = false; VPOzt7:
h[eCi
C7PVJnY0
while(!bStop) -_@zyF<G
{ iM \3~3'
write_nPos(); 3XykIj1
Utility.sleep(500); =Q+i(UGHi
breakWhile = true; Yf1&"WW4
WXq=FZ-
{"kEu
for(int i=0;i<nStartPos.length;i++) Y=G9|7*lO
{ .M(')$\U
if(!fileSplitterFetch.bDownOver) >-S?rXO
{ H(|n,c
breakWhile = false; v9*ugu[K9
break; o,qq*}=
} c_V^~hq
} j8Pqc]
if(breakWhile) CG#lpAs
break; <O<Kf:i&c1
|h^[/
6ijL+5
//count++; Z%&$_-yJ
//if(count>4) sF.oZ>
// siteStop(); \NZ(Xk
} 5;v_?M!UCK
nR%ey"
%<dvdIB
System.err.println("文件下载结束！"); Fh8 8DDJ
} L i g7Ac,
catch(Exception e){e.printStackTrace ();} zv%]j0 ?
} ]S
gm^j8B
6DkFIkS
//获得文件长度 *sJT\J$D[
public long getFileSize() gWk?g^KJL
{ 0Y>5&
int nFileLength = -1; pseN!7+or
try{ Fal##6B
URL url = new URL(siteInfoBean.getSSiteURL()); EKgY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r!+..c
httpConnection.setRequestProperty("User-Agent","NetFox"); QT8GP?F
C4[)yJ
Yamu"#
int responseCode=httpConnection.getResponseCode(); X&LaAqlSG
if(responseCode>=400) <6.aSOS
{ 8(3nv[
processErrorCode(responseCode); V><,.p8
return -2; //-2 represent access is error @5RbMf{
} )tvP|
:?!b\LJ2^
?d!*[Ke8
String sHeader; #Vy8<Vy&w
!+FrU'^
Q6 oM$qiM
for(int i=1;;i++) z@<OR$/`L
{ g)Tr#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <(Rbu2_
//Utility.log(in.readLine()); :~^_*:
sHeader=httpConnection.getHeaderFieldKey(i); vZiuElxKi
if(sHeader!=null) K0aT(Rc e
{ mAM:Q*a'
if(sHeader.equals("Content-Length")) 5FJ(x:k?z
{ P.y06^ X}A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0:iR=S
break; #lfW0?Y'
} oBS m>V
} p3,m),
else [%c5MQ?H
break; _|Uv7>}J^
} _j\GA6
} XN^l*Q?3n
catch(IOException e){e.printStackTrace ();} \Ota~A
catch(Exception e){e.printStackTrace ();} sRI0;
^7Rc\
>d3`\(v-
Utility.log(nFileLength); WR"?j9y_q
B"Ma<"HU
ey]WoUZ
return nFileLength; <*Gd0 v%
} a$=He
^qY?x7mx1
eH_< <Xh!v
//保存下载信息（文件指针位置） XfQK kol
private void write_nPos() J))U YJO
{ fi~jT"_CI
try{ ,W|cyQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); $L4h'(s
output.writeInt(nStartPos.length); rT|wZz9$@
for(int i=0;i<nStartPos.length;i++) ?CD[jX}!
{ im3BQIPR
// output.writeLong(nPos); 4%$#
output.writeLong(fileSplitterFetch.nStartPos); it$w.v+W7V
output.writeLong(fileSplitterFetch.nEndPos); } *jmWP
} %a:>3! +
output.close(); 4aiI&,
} tfCK^{
catch(IOException e){e.printStackTrace ();} (PC)R9r5
catch(Exception e){e.printStackTrace ();} 2EH0d6nt
} Ya&\b 6
ffQm"s:P
:+_
//读取保存的下载信息（文件指针位置） eakQZ-Q
private void read_nPos() r3NdE~OAi
{ "x0/i?pqa
try{ hLr\;Swyp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /o^/J~/3
int nCount = input.readInt(); _+9o'<#u(
nStartPos = new long[nCount]; m%cwhH_B
nEndPos = new long[nCount]; G3o`\4p
for(int i=0;i<nStartPos.length;i++) }60/5HNr
{ 3UX6Y]E3
nStartPos = input.readLong(); &Nw[J5-"k
nEndPos = input.readLong(); +O)Y7k{?C5
} ?="?)t[
input.close(); 0VZC7@
} 4(dgunP
catch(IOException e){e.printStackTrace ();} mpNS}n6
catch(Exception e){e.printStackTrace ();} ?_7iL?
} &;naaV_2T
TT oW>RP#
%i.Prckrb
private void processErrorCode(int nErrorCode) fZp3g%u
{ |s,y/svp
System.err.println("Error Code : " + nErrorCode); K: |-s4=
} h])oo:u'/Q
{TZV^gT4
DB+oCE<.#
//停止文件下载 bao"iv~z
public void siteStop() FeNNzV=
{ qfX26<q
bStop = true; "QvTn=
for(int i=0;i<nStartPos.length;i++) N F,<^ u
fileSplitterFetch.splitterStop(); CiV^bYi
^ib =fLu
mqtYny'
} iS< ^MD
} R;zf x/
//负责部分文件的抓取 uO)vGzt3^x
**FileSplitterFetch.java 2;K2|G7
*/ Jflm-Hhsf
package NetFox; J|w%n5Y
8O_yZ ~Z4
Us.k,
import java.io.*; Ae%AG@L
import java.net.*; _\gCdNrD
]v]tBVO$
"d`u#YmR
public class FileSplitterFetch extends Thread { 7&dK_x,a
6!se,SCvw
-ykD/
String sURL; //File URL *,zrg%8
long nStartPos; //File Snippet Start Position e{H(
long nEndPos; //File Snippet End Position n]6-`fpD
int nThreadID; //Thread's ID #-o 'g!
boolean bDownOver = false; //Downing is over T!I3.
boolean bStop = false; //Stop identical +KaVvf
FileAccessI fileAccessI = null; //File Access interface g4y&6!g
I_ AFHrj
(*_lLM@Cd
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LJ K0WWch
{ ,M~> t7+
this.sURL = sURL; dvM%" k
this.nStartPos = nStart; phQ{<wzwp
this.nEndPos = nEnd; k?rJGc G
nThreadID = id; ]:;dJc'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \XO'7bNu-
} &;sW4jnt
~6K.5t7
R9(Yi<CC
public void run() Dr76+9'i
{ JLt%G^W>
while(nStartPos < nEndPos && !bStop) E3] 8(P%D-
{ :5F(,Z_
l"7#(a
U~d%5?q
try{ 'Z]wh.]T
URL url = new URL(sURL); NTEN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rHi4Pw{L
httpConnection.setRequestProperty("User-Agent","NetFox"); dtE"1nR
String sProperty = "bytes="+nStartPos+"-"; NwxDxIIH/)
httpConnection.setRequestProperty("RANGE",sProperty); '\GU(j
Utility.log(sProperty); 1:r#m- \
_u'y7-
Uy.ihh$I-
InputStream input = httpConnection.getInputStream(); ^^lx Ot
//logResponseHead(httpConnection); ?bpVdm!
-:kIIK
J"Fp),
byte[] b = new byte[1024]; 7<Qmpcp =
int nRead; wFMw&=j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4*D"*kR;
{ /2 hk9XM
nStartPos += fileAccessI.write(b,0,nRead); &po!X )
//if(nThreadID == 1) EqGpo_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~ivOSr7s}
} gX7R-&[UD
)Ay90Wt
.lq83; k
Utility.log("Thread " + nThreadID + " is over!"); &r,)4q+
bDownOver = true; g~$UU(HX
//nPos = fileAccessI.write (b,0,nRead); `/?'^A%Ik
} =6+99<G|%M
catch(Exception e){e.printStackTrace ();} +xgP&nw[-
} 3Fxr=
} E NCWOj
T--%UZD]W
?z <-Ww
//打印回应的头信息 JypP[yQ
public void logResponseHead(HttpURLConnection con) nt+OaXe5D
{ 9UVT]acq
for(int i=1;;i++) }-J0cV
{ 1;DRcVyS+
String header=con.getHeaderFieldKey(i); V#b=mp
if(header!=null) @OGG]0 J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fUGappb
Utility.log(header+" : "+con.getHeaderField(header)); Zxhbnl6
else q3#+G:nh
break; (Q @'fb9z
} 9zS
} 7(oA(l1V
`R>z{-@=
KQvSeH>r
public void splitterStop() ~**x_ v
{ .Zj`_5C
bStop = true; C\aHr!
} vf$IF|
ji ./m8(
G~v:@
} ~;a\S3
HsUh5;
#r]Z2Y]
/* .)_2AoT7[
**FileAccess.java ~#jiX6<I
*//文件访问(定位，写) 7Xu#|k
package NetFox; zA8@'`Id
import java.io.*; wpN3-D
d6ef)mw
Lt=32SvTn
public class FileAccessI implements Serializable{ 1YJ?Y
biU_ImJ>0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |Tc4a4jS
RandomAccessFile oSavedFile; zL9~gJ
long nPos; $+_1F`
fK+ 5
pjX=:K|
public FileAccessI() throws IOException Eu:/U*j
{ C}pm>(F~
this("",0); <R;wa@a>
} _^NaP
6%ofS8[
$Seh4
public FileAccessI(String sName,long nPos) throws IOException @+H0D"
{ l EzN
oSavedFile = new RandomAccessFile(sName,"rw"); T'vI@i9
this.nPos = nPos; c9fz x
oSavedFile.seek(nPos); VXWV Pj#
} `=P_ed%&'
R:YVmqd
FZ?eX`,
public synchronized int write(byte[] b,int nStart,int nLen) Zfcf?&><
{ Xd5s8C/}
int n = -1; o2U5irU
try{ <j>;5!4!}
oSavedFile.write(b,nStart,nLen); )\EIXTZY=
n = nLen; Ec}%!p_$
} $/D?Vw:]
catch(IOException e) NytTyk)
{ T|wz%P<J
e.printStackTrace (); h!K" ;qw
} G^#>HE|
<{Y3}Q
]6[+tpx
return n; 3CjixXaA$
} aG^E^^Y
v9-4yZU^WR
IPK1g3Z
} 7~XA92
vm_]X{80;
W/xPVmnV
/* S-q"'5>
**SiteInfoBean.java t#|R"Q#
*/ CvE^t#Bok
package NetFox; *c[w9(fU
8|=C/k
(w)%2vZ^
public class SiteInfoBean { yzp#
r8:"\%"f>
!zF07.(E
private String sSiteURL; //Site's URL 5l1R")0`t_
private String sFilePath; //Saved File's Path 7<!x:G?C
private String sFileName; //Saved File's Name f^B'BioW(
private int nSplitter; //Count of Splited Downloading File 4Ii5V c
'(3 QyCD
P@ew' JL%
public SiteInfoBean() 8`urkEI^r
{//nSplitter的缺省值为5 ub-e!{
//default value of nSplitter is 5 FEu"b@v
this("","","",5); SfC* ZM}<
} ||QK)$"
%p )"_q!ge
cMZy~>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2SC-c `9)
{ M.t,o\xl
sSiteURL= sURL; U|tacO5w`
sFilePath = sPath; Od~uYOL/B
sFileName = sName; */aQ+%>jf
this.nSplitter = nSpiltter; $&Vba@v
ZH;4e<gg
TS9<uRO0
} (LmU\Pe%
cYK:Y!|`F
L<@*6QH
public String getSSiteURL() 5)'Y\~2
{ ajk}&`Wj"
return sSiteURL; C0N}B1-MU
} O[t?*m1/
GkI'.
XdCP!iq*8
public void setSSiteURL(String value) E#:!&{O
{ =EFh*sp
sSiteURL = value; /Tm+&Jd
} 2A~o)7JaZ
\]f+{d-&
j AOy3c
public String getSFilePath() dv\bkDF4A
{ gR# k'
return sFilePath; M9R'ONYAa
} Eqz|eS*6
(JlPe)Q5
]VKQm(,0
public void setSFilePath(String value) eZ(ThA*2=t
{ Gm:s;w-;v
sFilePath = value; %6uZb sa
} 4vWiOcJF!O
PB$beQ
!;,\HvEZYw
public String getSFileName() -#9et30
{ =YgH-{
return sFileName; 9h\RXVk{tA
} +S0aA Wal
_|I8+(~)
["Ts7;q9[
public void setSFileName(String value) {Z8GG
{ 2H.g!( Oza
sFileName = value; /}~=)QHH
} 7yyX8p>
Rkg8
NJsaTBT
public int getNSplitter() U&BCd$
{ KLW5Ad:/rI
return nSplitter; T(x@gwc
} L5x;#\#p
x6R M)rr
E8r6P:5d`
public void setNSplitter(int nCount) N Nk
{ "NA<^2W@J
nSplitter = nCount; XyN " Jr
} $+GDPYm'
} jdJTOT
8b'@_s!_
UU>+b:
/* P*iC#w]m
**Utility.java bI:W4y>I=
*/ 5e,u*J]
package NetFox; |3e+ K.
l%_K$$C
K:'^f? P
public class Utility { 85G-`T
<<?32r~
?ld&}|W~
public Utility() 6ScB:8M
{ } uS0N$4
N!~]D[D
b_nE4>
} :5CyR3P
o-H?q!
//线程睡眠 v%T'!(0j/
public static void sleep(int nSecond) a r8iuwfZ
{ gyAJ#N|
try{ [G$#jUt/O
Thread.sleep(nSecond); 5xdeuBEY8
} 4t(/F`
catch(Exception e) hH5~T5?\
{ f}2}Ta
e.printStackTrace (); Z C01MDIY
} _*e_?]G-
} rc[~S
9qCE{[(
//日志 m_0y]RfG
public static void log(String sMsg) .8s-)I
{ f#:3TJV
System.err.println(sMsg); %f&Y=
} YOLzCnI4
uT,i&
,V!"4T,Z
public static void log(int sMsg) i,ZEUdd*_
{ 2k<#e2
System.err.println(sMsg); 8_4!Ar>2
} e%)iDt\j
} _x(hlHFk
082iEG
dVB#Np
/* *KDTBd
**TestMethod.java hJ ^+asr
*/ b]z_2h~`
package NetFox; 1Zc=QJw@
03 gbcNo
FhY#3-jH
public class TestMethod { R&(OWF;~,
WcqR; Nm
EQlb:;j
public TestMethod() \54B
{ ///xx/weblogic60b2_win.exe &Iy5@8
try{ 9pnOAM}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %Ve@DF8G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5n2!Y\
SiteFileFetch fileFetch = new SiteFileFetch(bean); C lf;+G0
fileFetch.start(); &6OY^6<
} af |mk@
catch(Exception e){e.printStackTrace ();} 6k;5T
L>IP!.J]?
w;ZT-Fti
} <}[ !k<
*:TwO=)
QD!NV*
public static void main(String[] args) c6vJ;iz
{ C8|Ls(4Ck
new TestMethod(); k@lJ8(i^qU
} ?:9y !Q=
} Vv+nq_
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