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)); 6no&2a|D
} uPVO!`N3
for(int i=0;i<nEndPos.length-1;i++) 0{'m":D9
{ Wx`$hvdq
nEndPos = nStartPos[i+1]; 3P*[!KI
} M:*)l(
nEndPos[nEndPos.length-1] = nFileLength; e9;5.m
} Kgw,]E&7
} 6hO]eS
S}3?
c6Z"6-}$
//启动子线程 xUF5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; B!x7oD9
for(int i=0;i<nStartPos.length;i++) 5hl!zA?
{ #|QA_5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j a'_syn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |/%X8\
nStartPos,nEndPos,i); S[e> 8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zi_0*znw
fileSplitterFetch.start(); P r2WF~NuO
} Ou]!@s
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q"s]<MtdS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O?f?{Jsx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u\3=m%1
nEndPos = " + nFileLength); -`CE;
// fileSplitterFetch[nPos.length-1].start(); A~@x8
pG^>y0
uC|bC#;
//等待子线程结束 %$&_!
//int count = 0; WS.lDMYE7
//是否结束while循环 QKIg5I-
boolean breakWhile = false; MmQk@~
>ra)4huZ
gs(ZJO1 /L
while(!bStop) 6J<R;g23R]
{ *o=[p2d"X
write_nPos(); &9EcgazV
Utility.sleep(500); 2-%9k)KH
breakWhile = true; wW, n~W
W.c>("gC
48)D%867.;
for(int i=0;i<nStartPos.length;i++) gLwrYG7@
{ .1:B\R((
if(!fileSplitterFetch.bDownOver) e3k58
{ ! JauMR
breakWhile = false; Zg3 /,:1
break; ^+wA,r.
} {ceY:49
} mq+x=
if(breakWhile) {n{-5Y
break; TR9dpt+T
-VvN1G6.x?
W.l#@p
//count++; ;0o% hx
//if(count>4) fwi -
// siteStop(); %-L T56T
} d^Rea8
m[nrr6 G"
o|APsQE
System.err.println("文件下载结束！"); ;)Sf|
} #s{EIj~YR_
catch(Exception e){e.printStackTrace ();} |`pDOd
} O jH"qi
s;#,c(
UHS"{%
//获得文件长度 K$wxiGg8P
public long getFileSize() 6GoQJ
{ 0py29>"t
int nFileLength = -1; ))6YOc
try{ ?>NX}~2cf
URL url = new URL(siteInfoBean.getSSiteURL()); s)#TT9BbV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U U3o(Yq
httpConnection.setRequestProperty("User-Agent","NetFox"); L0qL\>#ejr
xHe"c<
C8O<fwNM
int responseCode=httpConnection.getResponseCode(); qG3MyK%O\
if(responseCode>=400) <l<y R?
{ C6qGCzlG`
processErrorCode(responseCode); A+KpECP
return -2; //-2 represent access is error -ZoAbp$
} UlPhW~F)
y;fnC5Q
r`sG!
String sHeader; XHm6K1mGZ
De\Ocxx
kBtzJ#j B
for(int i=1;;i++) Q"K`~QF"
{ IeAi'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); C3KAQU
//Utility.log(in.readLine()); n2Y a'YF
sHeader=httpConnection.getHeaderFieldKey(i); N7!(4|14
if(sHeader!=null) "(iQ-g Mm
{ "}b/[U@>
if(sHeader.equals("Content-Length")) AG|:mQO
{ *9US>mVy
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LCqWL1
break; S&F;~
} x_- SAyH
} e 3TKg
else \"9ysePI
break; #Eqx Eo;
} 6M[OEI5
} s0'6r$xj
catch(IOException e){e.printStackTrace ();} SP4(yJy&
catch(Exception e){e.printStackTrace ();} P&Wf.qr{:
*t`=1Ioj
k/i&e~! \
Utility.log(nFileLength); xu@+b~C\
vBV_aB1{
Ah;`0Hz;
return nFileLength; X.AE>fx*h
} hLaQ[9
F#z1 sl'
Fnuheb'&m
//保存下载信息（文件指针位置） 0U!_o2]
private void write_nPos() TVK*l*
{ >:0^v'[
try{ =WK's8FB;8
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7!~)a
output.writeInt(nStartPos.length); |Ew&.fgz
for(int i=0;i<nStartPos.length;i++) oN,9#*PVL
{ !gi3J @
// output.writeLong(nPos); d!y_N&z|(
output.writeLong(fileSplitterFetch.nStartPos); 8Rnq &8A
output.writeLong(fileSplitterFetch.nEndPos); QEP|%$:i
} Kc`#~-`,(
output.close(); &(NW_<(
} 'JJ :
catch(IOException e){e.printStackTrace ();} of>H&G)@
catch(Exception e){e.printStackTrace ();} A`V:r2hnb
} L(}/W~En
4 ;^
h5lngw
//读取保存的下载信息（文件指针位置） j|VX6U
private void read_nPos() !Hj 7|5
{ Vg7BK%
try{ AIw~@*T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |5*:ThC[
int nCount = input.readInt(); <W/YC2b
nStartPos = new long[nCount]; jWK>=|)=c
nEndPos = new long[nCount]; [ub)`-6 u
for(int i=0;i<nStartPos.length;i++) 58]t iP"
{ UW&K\P
nStartPos = input.readLong(); Mr@{3do$
nEndPos = input.readLong(); c LfPSA
} ootkf=
input.close(); 1$ENNq#0
} kZ=yb-~
catch(IOException e){e.printStackTrace ();} K*5Ij]j&
catch(Exception e){e.printStackTrace ();} Y r8gKhv W
} /U="~{*-R
e'~<uN>
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private void processErrorCode(int nErrorCode) nbBox,zW
{ y27MG
System.err.println("Error Code : " + nErrorCode); +u3vKzD
} 70Ei<
@1V?94T1
F 7X] h
//停止文件下载 9Yji34eDZ
public void siteStop() k"+/DK,:
{ *enT2Q
bStop = true; CL5t6D9Qi
for(int i=0;i<nStartPos.length;i++) 5oR)
fileSplitterFetch.splitterStop(); 8|Wl|@1(
$HAwd6NI
tY60~@YO&
} dl+c+w"
} O`.IE? h#
//负责部分文件的抓取 >viLvDng
**FileSplitterFetch.java o:@A%*jg
*/ e*39/B0S
package NetFox; XXb,*u 3
LGWQBEXw
T/q*k)IoR
import java.io.*; 4TcW%
import java.net.*; tw<}7l_>Au
p+Fh9N<F9
UbP$WIrq
public class FileSplitterFetch extends Thread { ;eMb$px
;MW=F9U*
:Y4G^i
String sURL; //File URL qR^+K@*|
long nStartPos; //File Snippet Start Position $~r=I[5'(
long nEndPos; //File Snippet End Position qcfg 55]'c
int nThreadID; //Thread's ID '3B7F5uLx"
boolean bDownOver = false; //Downing is over Lp{/
boolean bStop = false; //Stop identical on f7V
FileAccessI fileAccessI = null; //File Access interface ]"i^VVw
#3YYE5cB
]gVW&3ZW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i7`/"5I
{ z"Wyf6H0T
this.sURL = sURL; >"D0vj
this.nStartPos = nStart; 8[IR;gZf
this.nEndPos = nEnd; gO bP
nThreadID = id; )NlxW5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WU6F-{M"?
} TWU1@5?Ct
'L2[^iF9
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public void run() ?IR+OCAA
{ &IFXU2t}
while(nStartPos < nEndPos && !bStop) <^adt *m
{ f4^\iZ{`G
BsYJIKfW
s+a#x(7{
try{ ,772$7x
URL url = new URL(sURL); %D[6;PT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |w.5*]?H
httpConnection.setRequestProperty("User-Agent","NetFox"); +\Je B/F
String sProperty = "bytes="+nStartPos+"-"; j`-9.
httpConnection.setRequestProperty("RANGE",sProperty); 0fx.n
Utility.log(sProperty); kQ.3J.Q5
|k)Nf+(}W
k'K 1zUBj
InputStream input = httpConnection.getInputStream(); }Q_ }c9?
//logResponseHead(httpConnection); W<H<~wf#
- S%8
K}Lu1:~
byte[] b = new byte[1024]; Sp@{5
int nRead; S~{}jvc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nb(Od,L
{ y&2O)z!B
nStartPos += fileAccessI.write(b,0,nRead); @*JS[w$1
//if(nThreadID == 1) 7/FF}d
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :qvaI,
} 8o,"G}Hjk
zl$z>z)
0y=lf+xA*
Utility.log("Thread " + nThreadID + " is over!"); SoB6F9
bDownOver = true; 34qfP{9!N
//nPos = fileAccessI.write (b,0,nRead); !p3vnOX6
} Xl/2-'4
catch(Exception e){e.printStackTrace ();} 19i[DR
} \`YV)"y" ~
} fCi1JH;
`^ uX`M/
h5@JS1cY
//打印回应的头信息 \PK}4<x}
public void logResponseHead(HttpURLConnection con) u=sZFr@m[
{ 6"La`}B(T8
for(int i=1;;i++) 4z,n:>oH
{ +qmV|$rmM
String header=con.getHeaderFieldKey(i); j.UO>1{7
if(header!=null) YJBf~0r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mA6Nmq%{ F
Utility.log(header+" : "+con.getHeaderField(header)); incUa;
else ASaNac-3
break; tN&X1
} ;h7O_|<%
} E^t}p[s
2$?j'i!
G4)X~.Fy
public void splitterStop() \yY2 mr
{ r'& 6P-Vm
bStop = true; P>ZIP* Gr
} >Q|S#(c
jR{Rd}QtQ
]D|Hq4ug
} N"2P]Zr
x: 2 o$+v3
.$"69[1H
/* \rmge4`4
**FileAccess.java xMo'SpVz:
*//文件访问(定位，写) ?4lDoP{
package NetFox; B0:/7Ld$Ml
import java.io.*; Ml9
J.n-4J#@
IJofbuzw:
public class FileAccessI implements Serializable{ Nrk/_0^
Eb9{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 S$ 91L
RandomAccessFile oSavedFile; s F3M= uz
long nPos; ,98`tB0
aKC3vR0
+zSdP2s
public FileAccessI() throws IOException ~bLhI
{ `r.
this("",0); Mt+ggF.
} \FjY;rqfKe
3ypf_]<
firiYL"=44
public FileAccessI(String sName,long nPos) throws IOException Be2yS]U
{ BI0 A0
oSavedFile = new RandomAccessFile(sName,"rw"); Qb&gKQtt@
this.nPos = nPos; F[==vte|
oSavedFile.seek(nPos); RTvzS]
} q<wQ/m
qn~:B7f
=j S
public synchronized int write(byte[] b,int nStart,int nLen) !gFUC<4bu
{ kIYV%O
int n = -1; &p:GB_
try{ N!^5<2z@eT
oSavedFile.write(b,nStart,nLen); kS$m$ D
n = nLen; a1# 'uS9W
} ;U$EM+9
catch(IOException e) ]$?\,`
{ f)!7/+9>
e.printStackTrace (); FK.Qj P:
} P};GcV-
uM('R;<^
?FwjbG<
return n; Af7&;8pM
} HU+zzTgI
=CjN=FM
nwPU{4#l<
} K^+}__;]
q.NvwJ
,N`D{H"F
/* M[,G#GO
**SiteInfoBean.java z+6%Ya&ls
*/ Z|qUVD5Ic
package NetFox; cp<jwcc!
9aZ^m$tAt
}uk]1M2=
public class SiteInfoBean { lF.yQ
;B@-RfP
,]|*~dd>G
private String sSiteURL; //Site's URL *'nZ|r v
private String sFilePath; //Saved File's Path Hnc<)_DF
private String sFileName; //Saved File's Name 3eP7vy
private int nSplitter; //Count of Splited Downloading File SjB#"A5
]<?7CpP
mL[Y{t#N
public SiteInfoBean() *IBCThj
{//nSplitter的缺省值为5 u3@v
//default value of nSplitter is 5 e&J_uG
this("","","",5); qI#ow_lL#
} uV+.(sjH
%t<ba[9F
UV8K$n<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W05>\Rl
{ &[|P/gj#>
sSiteURL= sURL; dt|f4XWF
sFilePath = sPath; ~6-6aYhe
sFileName = sName; h`b[c.%
this.nSplitter = nSpiltter; *]RCfHo\=
a#4 'X*
SebJ}P1x
} 2%(RB4+
*oU-V#
Y]>Qu f.!
public String getSSiteURL() O)Mf/P'
{ "/}cV5=Z
return sSiteURL; @O%d2bgEWV
} ;IYH5sG{
KK4"H]!.
f:|O);nM
public void setSSiteURL(String value) hXx.
{ ?\$\YX%/p
sSiteURL = value; [.`%]Z(
} q^k]e{PD
@ME .
njN]0l{p
public String getSFilePath() mtn+bV R%
{ %:WM]dc
return sFilePath; '4}c1F1T_
} <UMT:`h1MZ
37QXML
]J* y`jn
public void setSFilePath(String value) wz(D }N5
{ O9tgS@*Tv
sFilePath = value; e=%6\&q
} ]~A<Q{
ZT'Sw%U:
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public String getSFileName() hpVu
{ 7yK1Q_XY>
return sFileName; 8${Yu
} eX@7f!uz
J\V.J/
3Ta<7tEM
public void setSFileName(String value) Cq-#|+zr
{ .6D9m.Q,
sFileName = value; }lzN)e
} ]9}T)Df'
`bF]O"
8K/o/
public int getNSplitter() q4rDAQyPO
{ >7^+ag~&
return nSplitter; r!7e:p JLO
} /NDuAjp[@
[Ifhh2
MlM2(/ok
public void setNSplitter(int nCount) f;"6I
{ 4fCg{
nSplitter = nCount; -=A W. Zo
} ;dh8|ujh
} \O7Vo<B&D
"<J%@
0u"/7OU
/* VI(;8
**Utility.java ]O;Hlty(g
*/ b88Zk*
package NetFox; |_P-
.V\M/q\Tv
!dW77kLTg
public class Utility { Hw"UJP
r4D6I,
-MqWcB9&
public Utility() C,!}WB@VME
{ E(&GZ QE
G2,r%|7ta
) -C9W7?I
} XI*_ti
C;jV{sb9c
//线程睡眠 Q#i^<WUpg
public static void sleep(int nSecond) _x.D< n=X
{ ,OQ!lI_`R
try{ XT|!XC!|
Thread.sleep(nSecond); weOzs]uc
} &z\]A,=Tc
catch(Exception e) ;|hEXd?b
{ B!(t<W8cu
e.printStackTrace (); ffQ%GV_
} BU="BB/[
} yq?_#r
_0rHxh7}q
//日志 GD$jP?
public static void log(String sMsg) 28j=q-9Z
{ `37GVo4
System.err.println(sMsg); | 3`qT#p{
} ; YaR|)B
}bv0~}G4
/ h6(!-"
public static void log(int sMsg) Z`?<Ada
{ q-.e9eoc\
System.err.println(sMsg); !vQ!_|g1
} 1@ j>2>i
} G=8w9-Ww
>t"]gQHtx
jj)9jUz
/* 4pF U`g=
**TestMethod.java m\lSBy6
*/ ,qRSB>5c
package NetFox; / -=(51}E
jz[|rwAp
lK^Q#td:`
public class TestMethod { :{9|/a
[hg|bpEG
T2wn!N?r
public TestMethod() afEp4(X~
{ ///xx/weblogic60b2_win.exe W7as=+;X
try{ fJCh
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G5Ci"0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k"SmbFn%N0
SiteFileFetch fileFetch = new SiteFileFetch(bean); bH41#B
fileFetch.start(); oPNYCE
} y0qE::/H$
catch(Exception e){e.printStackTrace ();} g)'tr '
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\2<2&=h?
} =3=KoH/'
zJMKgw,i*
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public static void main(String[] args) LeW.uh3.
{ qD\%8l.]Z
new TestMethod(); (nrrzOax
} AEwb'
} 4(4JQ(5
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