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)); &=~Jw5WK
} S3$&}I <
for(int i=0;i<nEndPos.length-1;i++) Ch>r.OfP
{ )m|)cLT&
nEndPos = nStartPos[i+1]; f]Xh7m(Gh
} UZz/v#y~
nEndPos[nEndPos.length-1] = nFileLength; `fS$@{YI_
} ]@0C1r
} )1N~-VuT
Dr)B0]KG
7*.nd
//启动子线程 h:xvnyaI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <v%Q|r
for(int i=0;i<nStartPos.length;i++) 0-6rIdDTM
{ :pq+SifP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -e(e;e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `p#tx.o
nStartPos,nEndPos,i); Zcjh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x.8fxogz
fileSplitterFetch.start(); LtW}R4}3
} O |!cPB:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k..AP<hH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }20~5!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uVN2}3!)Y
nEndPos = " + nFileLength); f?W_/daP
// fileSplitterFetch[nPos.length-1].start(); 4 Fl>XM
]Q$Sei5
t^ Ge"
//等待子线程结束 !Ah v07SI
//int count = 0; )Vd^#p
//是否结束while循环 $t0o*i{
boolean breakWhile = false; f\xmv|8
- ({h @
{.eo?dQ
while(!bStop) *O_>3Hgl
{ >jz9o9?8
write_nPos(); xu\s2x$
Utility.sleep(500); w$iQ,--
breakWhile = true; MroN=%|t
xIA]5@;a
pmRm&VgE.
for(int i=0;i<nStartPos.length;i++) KrdEB0qh
{ 5\V""fH
if(!fileSplitterFetch.bDownOver) [4w*<({*
{ agt/;>q\~
breakWhile = false; Hsn'"
break; z^vfha
} qA0PGo
} iYD5~pK8
if(breakWhile) e.\dqt~%y
break; <p/zm}?')
DG?g~{Y~b
-U*J5Q
//count++; SSxp!E'
//if(count>4) ,.Lwtp,n
// siteStop(); DSQ2|{
} 9TX2h0U?
+-C.E
bgLa`8
System.err.println("文件下载结束！"); kMJ}sS
} \HXq~Y
catch(Exception e){e.printStackTrace ();} 60;_^v
} eSQkW
d~ +(g!
EHN(K-
//获得文件长度 OClG dFJ|
public long getFileSize() NOg/rDs'{
{ 0<7sM#sI!
int nFileLength = -1; k4a51[SYBK
try{ _3(rwD
URL url = new URL(siteInfoBean.getSSiteURL()); Unvl~lm6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \3OEC`
httpConnection.setRequestProperty("User-Agent","NetFox"); Ge_fU'F
Q3Pu<j}Y
URceq2_
int responseCode=httpConnection.getResponseCode(); "AU.Eh"-1
if(responseCode>=400) >"8;8Ev
{ 3~{I/ft
processErrorCode(responseCode); }4N'as/ZO
return -2; //-2 represent access is error 8OKG@hc
} qg{gCG
7HkFDI()1
}f;WYz5
String sHeader; :.4O Hp1
T%% 0W J
9dq"x[
for(int i=1;;i++) }4p)UX>aWT
{ Li]bU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b"WF]x|^
//Utility.log(in.readLine()); b"uO BB
sHeader=httpConnection.getHeaderFieldKey(i); ckMG4 3i\j
if(sHeader!=null) \_WR:?l
{ %cLS*=MO
if(sHeader.equals("Content-Length")) jYi,oE
{ C7ug\_,s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $2\8Rn6'
break; ~5'7u-;
} s3eS` rK-
} UAPd["`)y
else Lo3N)~5
break; :h5G|^
} $m;`O_-T
} y{/7z}d
catch(IOException e){e.printStackTrace ();} 0KnL{Cj
catch(Exception e){e.printStackTrace ();} M^[;{p2uZ
_tJt eDRY
jB8Q% {%
Utility.log(nFileLength); ele@xl
<Xl#}6II
%ggf|\-e
return nFileLength; P&sWn?q Ol
} )w0x{_
sEFQ8S
@QV0l]H0+
//保存下载信息（文件指针位置） *#'j0;2F
private void write_nPos() tBbOxMm0
{ PQDLbSe)\
try{ +=jS!
output = new DataOutputStream(new FileOutputStream(tmpFile)); Bhxs(NO
output.writeInt(nStartPos.length); :~ pGHl
for(int i=0;i<nStartPos.length;i++) 3("C'(W
{ KEtV
// output.writeLong(nPos); Sp492W+
output.writeLong(fileSplitterFetch.nStartPos); Xd=KBB[r?
output.writeLong(fileSplitterFetch.nEndPos); gzIx!sc
} [02rs@c>
output.close(); tGgxID
} /kY9z~l
catch(IOException e){e.printStackTrace ();} db~^Gqv6k
catch(Exception e){e.printStackTrace ();} 5>I-? Ki
} JcWp14~e
4d`YZNvZW/
qFD ZD)K
//读取保存的下载信息（文件指针位置） 3Rc*vVnI
private void read_nPos() 4~,Z 'k
{ d #1Y^3n
try{ H"FK(N\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *{3d+j/?/
int nCount = input.readInt(); lG)wa
nStartPos = new long[nCount]; \P*_zd@%
nEndPos = new long[nCount]; l)9IgJ|<b
for(int i=0;i<nStartPos.length;i++) bZNqv-5 4h
{ B W<Dmn
nStartPos = input.readLong(); Z#Mm4(KNh
nEndPos = input.readLong(); se\fbe^0
} m,lZy#02s3
input.close(); ^1najUpQ_n
} $DoR@2~y
catch(IOException e){e.printStackTrace ();} -N8rs[c
catch(Exception e){e.printStackTrace ();} x="Wqcnj{
} P9/ (f$=
^+SE_-+]
7q+D}+ Xf
private void processErrorCode(int nErrorCode) 1(gs({
{ q#tUDxf(|
System.err.println("Error Code : " + nErrorCode); bZ\R0[0
} s0/O/G?
$D1ha CL
itg_+%^R
//停止文件下载 j(=w4Sd_W
public void siteStop() hm,{C
{ (-gomn
bStop = true; h^SWb91"G
for(int i=0;i<nStartPos.length;i++) `gX|q3K\s
fileSplitterFetch.splitterStop(); D5,]E`jwu
oZa'cZNs
J,F1Xmr4
} 8M99cx*K
} fOV_ >]u
//负责部分文件的抓取 lI<jYd 0fZ
**FileSplitterFetch.java GGp.u@\r
*/ uzBQK
package NetFox; sp,-JZD
oX|T&"&
e9o\qEm
import java.io.*; 9MMCWMV
import java.net.*; G&ck98
0 0N[ :%
.xN<<+|_v'
public class FileSplitterFetch extends Thread { AJ\&>6GZ(b
zmo2uUEd
i"h\*B=
String sURL; //File URL %T({;/
long nStartPos; //File Snippet Start Position Sc7 Ftb%
long nEndPos; //File Snippet End Position >Uw:cq
int nThreadID; //Thread's ID )0VL$A
boolean bDownOver = false; //Downing is over jE*{^+n
boolean bStop = false; //Stop identical 7*l$i/!
FileAccessI fileAccessI = null; //File Access interface z`zz8hK.
A7%d
lU{)%4e`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $Zu?Gd?
{ +V4)><
this.sURL = sURL; gJQ#j~'
this.nStartPos = nStart; :W.H#@'(
this.nEndPos = nEnd; rYb5#aT[
nThreadID = id; )9hqd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WC#6(H5t$
} EhxpMTS
}u_D{bz
1Gsh%0r3
public void run() 2_q/<8t
{ %e~xO x
while(nStartPos < nEndPos && !bStop) W/qXQORv
{ L7$f01*
KN}#8.'>3
E_ wVAz3
try{ ` ,\b_SFg
URL url = new URL(sURL); ("8Hku?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !"N,w9MbD
httpConnection.setRequestProperty("User-Agent","NetFox"); /6')B !&
String sProperty = "bytes="+nStartPos+"-"; yaR>?[h
httpConnection.setRequestProperty("RANGE",sProperty); 2lTt
Utility.log(sProperty); }J#HIE\RG
*ERV\/
"t0^4=c+7
InputStream input = httpConnection.getInputStream(); J :O!4gI
//logResponseHead(httpConnection); cYA:k
Xdn&%5rI
B4y_{V
byte[] b = new byte[1024]; ZC?~RXL(
int nRead; t<45[~[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (Ceruo S
{ &<t%u[3
nStartPos += fileAccessI.write(b,0,nRead); }j/\OY _&
//if(nThreadID == 1) Rw?w7?I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "*bLFORkq'
} /HdXJL9B
74([~Qs _M
T8S&9BM7
Utility.log("Thread " + nThreadID + " is over!"); ]3 "0#Y
bDownOver = true; &W\e 5X<A
//nPos = fileAccessI.write (b,0,nRead); W`[VLi}fe
} `i`P}W!F
catch(Exception e){e.printStackTrace ();} ,;pUBrz/[
} dcf,a<K\
} jr`swyg
!]F`qS>
I):c#
//打印回应的头信息 "9;
public void logResponseHead(HttpURLConnection con) HxO+JI`'3
{ A?MM9Y}K
for(int i=1;;i++) TAYh#T=S
{ [j6]!p]S$
String header=con.getHeaderFieldKey(i); V D#q\
if(header!=null) sl$6Zv-l%0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^(q .f=I!a
Utility.log(header+" : "+con.getHeaderField(header)); .q2r!B
else Bl+\|[yd
break; uuM1_nD[
} sVh)Ofn
} I#OZ:g^
}ILBX4c
2hHRitt36
public void splitterStop() I bD u+~)
{ tR!C8:u
bStop = true; |>ztx}\
} )<QX2~m<
~>@~U]
ew\:&"@2]w
} &b (*
/`M#
e#oK% {A
/* ;r@=[h
**FileAccess.java 7&id(&y/
*//文件访问(定位，写) ,1I-%6L
package NetFox; {iyJHY
import java.io.*; N^QxqQ~
LuZlGm
/4+L2O[
public class FileAccessI implements Serializable{ .s\lfBo9
2*sTU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &<><4MQ
RandomAccessFile oSavedFile; M[qhy.
long nPos; ?b7ttlX{
{J"]tx9 ]
^|<>`i6
public FileAccessI() throws IOException 7)U ik}0
{ 3FvVM0l"
this("",0); Fx!D:.)/G
} MsIR~
E{)X ;kN=
4rDVCXE
public FileAccessI(String sName,long nPos) throws IOException ;=joQWNDm
{ T`^Jws{;7
oSavedFile = new RandomAccessFile(sName,"rw"); e#hg,I
this.nPos = nPos; ;8<HB1 &,
oSavedFile.seek(nPos); oLkzLJ
} g{Av =66Z
ASdW!4.p
=R:O`qdC4e
public synchronized int write(byte[] b,int nStart,int nLen) %f CkR`:
{ >K'dgJ245
int n = -1; uG -+&MU?
try{ 6D]fDeH\
oSavedFile.write(b,nStart,nLen); 4M%|N
n = nLen; /,SVG1
} qUfoEpW2=6
catch(IOException e) GLIY!BU<C
{ '`;=d<'
e.printStackTrace (); Z'A 3\f
} qMEd R;o
0to`=;JI
nP[Z6h
return n; KC"S06
} Rk5#5R n
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a;bmlV04
} 4Q#{,y944
yR~$i3Z*
~0+<-T
/* zf8SpQ2~
**SiteInfoBean.java CA|l| t^
*/ yT:2*sZRc
package NetFox; rV\G/)xL
UB+~K/
/*;a6S8q
public class SiteInfoBean { '__>M>[
TfJ*G6\7e#
uhj]le!
private String sSiteURL; //Site's URL rI\5djiYJ
private String sFilePath; //Saved File's Path z#Qe$`4&
private String sFileName; //Saved File's Name |(l]Xr&O
private int nSplitter; //Count of Splited Downloading File r<kgYU`
*A`ZcO=
UU(Pg{DA6
public SiteInfoBean() /t`|3Mw
{//nSplitter的缺省值为5 e<uf)K=(C
//default value of nSplitter is 5 w;Azxcw
this("","","",5); %AJ9fs4/
} V5-!w0{
%h(%M'm?
MtwlZg`c3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :@5{*o
{ _1RvK? ;.{
sSiteURL= sURL; E5A"sB
sFilePath = sPath; 3f$n8>mq
sFileName = sName; D5xQ
this.nSplitter = nSpiltter; CH(Y.Kj-
dSKvs"
5s\;7>
} |X*y-d77W
VMF?qT3Nd
v.*fJ
public String getSSiteURL() $@kOMT
{ Vo^J2[U
return sSiteURL; Kn3Xn`P?
} R`$Y]@i&B
CAx$A[f<
W%5))R$
public void setSSiteURL(String value) I*j~5fsS'
{ _QHk&-Lp
sSiteURL = value; [>>_%T\I
} oQpGa>6U&
)?OdD7gd
Kg~D~ +j
public String getSFilePath() QuMv1)n
{ G>:v1lde
return sFilePath; uX!6:v]
} O13]H"O_
{/)i}V#RE
vN v'%;L
public void setSFilePath(String value) H!0m8LCnb
{ _\yR/W~
sFilePath = value; ]%-U~avph
} 4Th?q{X
pRh9+1EM;
[;aM8N
public String getSFileName() /2d>nj
{ 1P"{TMd?
return sFileName; sqpo5~
} ";`jS&"=
\IC^z
L'a+1O1q&i
public void setSFileName(String value) 4".I*ij
{ r[^.\&-
sFileName = value; ._>03,"
} |AE{rvP{@
D=vw0Q_3Y3
#b&tNZ4!_
public int getNSplitter() pam9wfP
{ .3UJ*^(?
return nSplitter; I74Rw*fB
} h{_\okC>
^ )"Il
CG@Fn\J
public void setNSplitter(int nCount) 49>b]f,Vc
{ 4a&8G
nSplitter = nCount; eD(5+bm
} ld#x'/
} {[:C_Up)f
raOuD3
At[Q0'jkc
/* |*w)]2Bl
**Utility.java :zo5`[P
*/ e(0cz6
package NetFox; 9[X'9*,
.czUJyFms}
Fhllqh)
public class Utility { y@$E5sz
l="X|t
P5B,= K>r
public Utility() YCStX)r
{ GPGPteC
H-&27?s^
^Os }sJ*5S
} Qp[ Jw?a
p),*4@2<
//线程睡眠 E0VAhN3G\
public static void sleep(int nSecond) A0@,^|]
{ FXY>o>K%h
try{ 8<0P Ssx
Thread.sleep(nSecond); P 0+@,kM
} 3f^jy(
catch(Exception e) h*y+qk-!\g
{ $Yu'B_E6p
e.printStackTrace (); $X-PjQb1Bb
} &R.5t/x_
} ORP<?SG55u
1E||ft-1i*
//日志 XRkUv>Yk
public static void log(String sMsg) q,#s m'S
{ IEm~^D#<=
System.err.println(sMsg); (||qFu9a
} 'ParMT
8Uh|V&
SD*q+Si,1U
public static void log(int sMsg) z__t8yc3
{ PN9vg9'
System.err.println(sMsg); E=,b;S-
} Oprfp^L
} s&o9LdL
I:oEt
Ebj0 {ZL
/* w[l#0ZZ
**TestMethod.java rxMo7px@}I
*/ =$bF[3D
package NetFox; NTZ3Np`
kq(><T
F~E)w5?\O
public class TestMethod { 1Zp/EYWa{
uSI@Cjp
YR~e_cA:
public TestMethod() :ln|n6X
{ ///xx/weblogic60b2_win.exe Z R=[@Oi
try{ 2+)h!y]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "]p&7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); DFZ@q=ZT
SiteFileFetch fileFetch = new SiteFileFetch(bean); w0nbL^f
fileFetch.start(); ):tv V
} z]%@r 7
catch(Exception e){e.printStackTrace ();} Jia@HrLR
W\Scak>
`Nvhp]E
} BcpbS%S
GwDOxH'
KK>jV
public static void main(String[] args) _8K8Ai-~.>
{ JBw2#ry
new TestMethod(); uA =%EEZ
} Bx}"X?%S
} _nzq(m1@
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