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)); 5xMA~I0c
} 7TV>6i+7
for(int i=0;i<nEndPos.length-1;i++) yul<n>X|
{ Th~3mf #
nEndPos = nStartPos[i+1]; i9&K
} *X=@yB*aK
nEndPos[nEndPos.length-1] = nFileLength; Y|m_qB^_
} y/X:=d6"
} zj9bSDVL(
+Q SxYV
yhSk"e'G
//启动子线程 s<Ex"+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; FI?gT
for(int i=0;i<nStartPos.length;i++) I 9{40_
{ n&0mz1rw
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _[}G(<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }[>RxHd
nStartPos,nEndPos,i); a1 46kq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +,&m7L
fileSplitterFetch.start(); V17>j0Ev$W
} zB#_:(1qK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nd$H 3sf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~rgf{oGz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K/f>f;c
nEndPos = " + nFileLength); MB]#%g&
// fileSplitterFetch[nPos.length-1].start(); !dfS|BA]
Jh37pI
a&$Zpf!!
//等待子线程结束 Smqr q
//int count = 0; o,?!"*EP
//是否结束while循环 t{/:(Nu
boolean breakWhile = false; =oo[ Eyr
cm@jt\D
Np.no$_
while(!bStop) &u+yM D
{ 5z1\#" B[
write_nPos(); ZhhI@_sz
Utility.sleep(500); vC{h2A
breakWhile = true; FovE$Dj]
^~ Ekg:`
%==G+S{
for(int i=0;i<nStartPos.length;i++) XMt u"K
{ -Nsk}Rnk*
if(!fileSplitterFetch.bDownOver) lq:]`l,6@
{ 8K|J:[7
breakWhile = false; 1pd 9s8CA
break; 8h*t55
} r0)JUc}Fyq
} <_"B}c/2$
if(breakWhile) c*N50%=4
break; |w=Ec#)t4
seu ~'s-
?TIV2m^?
//count++; <KKDu$W|T
//if(count>4) Wt>J`
// siteStop(); TG1P=g5h
} tS?a){^:c
qOW#Q:T
"Owct(9
System.err.println("文件下载结束！"); fZ[kh{|
} ^`tk/#h\9F
catch(Exception e){e.printStackTrace ();} +C'XS{K,#
} `-4'/~G
9Hu d|n
-7k[Vg?
//获得文件长度 C`dkD0_
public long getFileSize() ;xfO16fNk
{ zm3-C%:Bw
int nFileLength = -1; YnSbw3U.I
try{ ar Q)%W
URL url = new URL(siteInfoBean.getSSiteURL()); <O.Kqk* nq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +fM&su=wl
httpConnection.setRequestProperty("User-Agent","NetFox"); #;`Oj
M~als3
88 {1mA,v
int responseCode=httpConnection.getResponseCode(); VKy5=2&
if(responseCode>=400) y`4{!CEyLW
{ b6|Z"{TI _
processErrorCode(responseCode); $`pd|K`
return -2; //-2 represent access is error )u0O_R
} e8oKn&
S`=n&'
[9OSpq
String sHeader; dXl]Pe|v
8"x9#kyU<3
I FsE!oDs4
for(int i=1;;i++) Y.>kO
{ J@QdieW6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _%{0?|=
//Utility.log(in.readLine()); 'G8 ?'u_)
sHeader=httpConnection.getHeaderFieldKey(i); *<IR9.~{6%
if(sHeader!=null) 4@6<
{ fz3lR2~G
if(sHeader.equals("Content-Length")) +Qs!Nhsq
{ LKx`v90p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vG~+r<:
break; }~F~hf>s
} mZ7B<F[qV
} -(9O6)Rs$
else G6V/SaD
break; 3CM^j<9
} [/cIUQ
} [(ygisqt
catch(IOException e){e.printStackTrace ();} mw4JQ\
catch(Exception e){e.printStackTrace ();} *g_w I%l
eLV.qLBUs
Ns<?b;aK
Utility.log(nFileLength); 8}BS2C%P
W pN.]x
RBE7485
return nFileLength; +AoP{x$Ia
} =u=Kw R
uE`r/=4
NEVp8)w
//保存下载信息（文件指针位置） XQ?fJWLU
private void write_nPos() ^"x<)@X
{ 'Jydu
try{ >b48>@~bY
output = new DataOutputStream(new FileOutputStream(tmpFile)); <bUXC@3W
output.writeInt(nStartPos.length); z)}!e,7
for(int i=0;i<nStartPos.length;i++) JoJukoy}F
{ 6+3$:?
// output.writeLong(nPos); ^m%52Tm h
output.writeLong(fileSplitterFetch.nStartPos); u,o1{%O
output.writeLong(fileSplitterFetch.nEndPos); . I==-|
} -bS)=L
output.close(); Fp%Ln(/m
} sbnjy"Z%
catch(IOException e){e.printStackTrace ();} dZ]Rqr _!
catch(Exception e){e.printStackTrace ();} ,Dp0fauJ
} rF] +,4
{eQWO.C{
Ur!~<4GO
//读取保存的下载信息（文件指针位置） "^Rv#
private void read_nPos() :(,mL2[
{ ? ?[g}>
try{ `PlOwj@u0`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1e}8LH7
int nCount = input.readInt(); y=Q!-~5|fF
nStartPos = new long[nCount]; %tmp
nEndPos = new long[nCount]; XAuI7e
for(int i=0;i<nStartPos.length;i++) "9XfQ"P
{ (=c1
nStartPos = input.readLong(); vzXag*0
nEndPos = input.readLong(); .H~YI
} ,_ .v_
input.close(); O0huqF$K
} (Rd$VYuf
catch(IOException e){e.printStackTrace ();} >jTp6tu,
catch(Exception e){e.printStackTrace ();} dRaOGm)
} P^)q=A8Z#
sKL:p3r
)9L/sKz
private void processErrorCode(int nErrorCode) O!&,5Dy
{ :P+\p=
System.err.println("Error Code : " + nErrorCode); f p[,C1U
} [L(hG a
M 2q"dz
)L5i&UK.
//停止文件下载 cWLqU
public void siteStop() ;\{`Ci\
{ '@=PGpRF
bStop = true; L,LNv
for(int i=0;i<nStartPos.length;i++) V/%~F6e
fileSplitterFetch.splitterStop(); Z(GfK0vU
(zcLx;N
](jFwxU
} Log|%P\
} ,d_Gn!
//负责部分文件的抓取 F]+~x/!
**FileSplitterFetch.java \6!W05[ Q
*/ D Ml?o:l
package NetFox; *rh,"Zo
ZH 6\><My
kcuzB+
import java.io.*; "Cz<d w]D
import java.net.*; ~O6\6$3b5E
('[TLHP
9KuD(EJS
public class FileSplitterFetch extends Thread { n/4i|-^
+&=?BC}L9^
jp2Q9Z
String sURL; //File URL Ond'R'3\E
long nStartPos; //File Snippet Start Position c1XX~8
long nEndPos; //File Snippet End Position \cJa;WM>
int nThreadID; //Thread's ID {KL5GowH
boolean bDownOver = false; //Downing is over ci9R.U)
boolean bStop = false; //Stop identical )Kd%\PP
FileAccessI fileAccessI = null; //File Access interface na+d;h*~y
~@W*r5/
Wr?'$:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ca<"
{ <%?#AVU[
this.sURL = sURL; k@mVxnC
this.nStartPos = nStart; ` uCIXb
this.nEndPos = nEnd; 2{|$T2?e
nThreadID = id; dtt~ Bd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;q>9W,jy
} s%4M$e
"Zv~QwC
0E`1HP"b
public void run() s#9Ui#[=h
{ ,E )|y4
while(nStartPos < nEndPos && !bStop) rVnd0K
{ $.%rAa_H
O[@q%&_
]b?9zeT*'l
try{ )RgGcHT@
URL url = new URL(sURL); >w6taX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *XOJnyC_H
httpConnection.setRequestProperty("User-Agent","NetFox"); xGk6n4Gg
String sProperty = "bytes="+nStartPos+"-"; V N{NA+I
httpConnection.setRequestProperty("RANGE",sProperty); \c,pEXG
Utility.log(sProperty); dq;|?ESP
5K%SL1N
qy1F*kY
InputStream input = httpConnection.getInputStream(); g`^X#-!(
//logResponseHead(httpConnection); .wA+S8}S
+EXJ\wy
VSX@e|Nj
byte[] b = new byte[1024]; ^ <`(lyph
int nRead; Ga>uFb}W~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U @v*0
{ )::>q5c
nStartPos += fileAccessI.write(b,0,nRead); h"mi"H^o
//if(nThreadID == 1) z+}QZ>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'wasZ b<^
} /wShUR{
EI~"L$?
^>x|z.
Utility.log("Thread " + nThreadID + " is over!"); N;oQ^B'
bDownOver = true; aVs(EHF
//nPos = fileAccessI.write (b,0,nRead); 9I7\D8r
} :,12")N
catch(Exception e){e.printStackTrace ();} 8F(h*e_?
} g1E~+@
} 85:NFa@J
1F'1>Bu~
s'aip5P
//打印回应的头信息 bu7'oB~:V^
public void logResponseHead(HttpURLConnection con) %=we`&
{ U6ZR->:
for(int i=1;;i++) '+>fFM,*B
{ w.\w1:d
String header=con.getHeaderFieldKey(i); 63|+2-E2Q
if(header!=null) l- pe4x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d,vNem-Z*L
Utility.log(header+" : "+con.getHeaderField(header)); MTER(L
else @oF$LMD
break; 9fnA
} AUVgPXOwd
} /M~!sPW&?
qSqI7ptA\
<:/&&@2
public void splitterStop() V-I(WzR9y
{ @$"J|s3M
bStop = true; p9U?!L!y
} &c(WE RW?-
u cwnA
-4w=s|#.\
} Xv <G-N4
YIt& >
,oxcq?7#4
/* $8USyGi3J
**FileAccess.java (iJ1 ;x
*//文件访问(定位，写) heaRX4
package NetFox; Tu{&v'!j6
import java.io.*; X8dR+xd
%<?0apO
;4M><OS!
public class FileAccessI implements Serializable{ R+q"_90_
RCTQhTy=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x83 !C}4:
RandomAccessFile oSavedFile; @~<j&FTT
long nPos; <Llp\XcZ
fP tm0.r
S-31-Zjw
public FileAccessI() throws IOException WwF~d+>|C
{ IW8+_#d
this("",0); I)q,kP@yY
} 4Wy<?O2
/(.6bv
ms($9Lv/
public FileAccessI(String sName,long nPos) throws IOException {mWui9 %M
{ ]sz3]"2
oSavedFile = new RandomAccessFile(sName,"rw"); kt[:@Nda9
this.nPos = nPos; )&era` e[
oSavedFile.seek(nPos); P o jmC
} {GvTfZfp
/vY_Y3k#
}?cGf-c
public synchronized int write(byte[] b,int nStart,int nLen) c`lJu_
{ ;fw1
int n = -1; /&u<TJ4
try{ 2fU$J>Y
oSavedFile.write(b,nStart,nLen); Ngr/QL]Q
n = nLen; ve ~05mg
} nf1#tlIJd
catch(IOException e) K.G$]H
{ f:g,_|JD$
e.printStackTrace (); y%sroI('y
} 7'wS\/e4a
&U+ _ -Ph
!R*-R.%
return n; Auy_K?he]
} 8Qh#)hiW!
g}laG8
iv phlw
} @ S<-d
tvXW
Z5c~^jL$-
/* pLMRwgzr
**SiteInfoBean.java g8!wb{8?s
*/ f84:hXo6
package NetFox; oG$)UTzGc
izKfU?2]X@
)>D+x5o]
public class SiteInfoBean { ,!V]jP)
p8s:g~ W
Z/^ u
private String sSiteURL; //Site's URL "cTncL
private String sFilePath; //Saved File's Path MNH1D!}
private String sFileName; //Saved File's Name >3awn*N
private int nSplitter; //Count of Splited Downloading File 0!z@2[Pe66
;q0uE:^S
b':|uu*/
public SiteInfoBean() /7!""{1\\
{//nSplitter的缺省值为5 $3Z-)m
//default value of nSplitter is 5 x8;`i$
this("","","",5); DK0.R]&4(
} mMMQ|ea
ExHKw~y9
A:<;M@q!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [~:-&
{ 2,aPr:]
sSiteURL= sURL; C"lJl k9g^
sFilePath = sPath; jGrN\D?h
sFileName = sName; UpXz&k
this.nSplitter = nSpiltter; $+}+zZX5
-@>BHC
&C>/L;
} )otb>w5
L6>pGx
TpA\9N#$
public String getSSiteURL() :';L/x>
{ vzF5xp.
return sSiteURL; [![%9'+P
} ??hJEE
[sW.CK=3
4@.|_zY
public void setSSiteURL(String value) ^\B:R,
{ iqnJ~g
sSiteURL = value; P;PQeXKw
} `Q+moX
V|)>{Xdn
~)?
public String getSFilePath() }HEvr)v9
{ \:> Wpqw
return sFilePath; eT'nl,e|
} 5>J=YLq
1Y_w5dU
A?TBtAe
public void setSFilePath(String value) )Qm[[pnj
{ uS&|"*pR
sFilePath = value; q P ;A}C
} \.XLcz
?=GXqbS"
(wc03,K^
public String getSFileName() ,wKe fpV;5
{ QZ `tNq :/
return sFileName; BQ^H? jo
} 569}Xbc/
-st7_3
39{{7(hh
public void setSFileName(String value) ,fEO> i
{ *%Qn{x
sFileName = value; lCW8<g^
} o`khz{SU:
BF{w)=@/'
)hwV`2>l
public int getNSplitter() ?}Z1(it0
{ M>jtFP<S
return nSplitter; P?BGBbC
} X\p,%hk \
(2?G:+C 7
RkFD*E$
public void setNSplitter(int nCount) &iN--~}!$
{ >]'yK!a?
nSplitter = nCount; ~.PP30'
} ,? E&V_5
} OT %nrzP
bg|!'1bD`5
eMK+X \
/* AvR2_
**Utility.java TJ?g%
*/ uhN%Aj\iu(
package NetFox; 0;,IKXK6X
Dc~,D1xWj
F2(q>#<_
public class Utility { ]IJRnVp%
/R X1UQ.s
wLuv6\E
public Utility() M8w5Ob
{ S)He$B$pp
(_* wt]"'
3`9{T>
} '+<(;2Z vL
Ju@Q6J5
//线程睡眠 0f ER*.F
public static void sleep(int nSecond) ')+0nPV
{ %u?HF4S'
try{ Fb2%!0i
Thread.sleep(nSecond); ~;-9X|
} us?&:L|!=
catch(Exception e) SM[{BH<
{ IL7`0cN(
e.printStackTrace (); 7J>Gd
} n)8Yj/5
} ]TO/kl/
$awi>#[
//日志 wh 0<Uv
public static void log(String sMsg) Vu0KtG9
{ ?y},,
System.err.println(sMsg); x)5V.q
} #i QX6WF
HN5W@5m: .
z?8~[h{i%
public static void log(int sMsg) uMXc0fs!$
{ 3bC yTZk
System.err.println(sMsg); OQ_stE2i
} [nN7qG
} 5''*UFIF1
>AD=31lq
[2$4|;7
/* !7lj>BA>
**TestMethod.java ^<V9'Ut
*/ ^Uw[x\%#gD
package NetFox; ?`sy%G
o|S)C<w
q/@dR{-
public class TestMethod { RcY[rnI6
t\U$8l_;
-@%%*YI>
public TestMethod() e]W0xC-
{ ///xx/weblogic60b2_win.exe jy$@a%FD
try{ #*IVlchA"B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,^T]UHRO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u,i]a#K
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,j980/
fileFetch.start(); K\=8eg93Z
} J2Et-Cz1
catch(Exception e){e.printStackTrace ();} /MMtTB H
=v2%Vs\7k
\&|CM8A
} nW;kcS*A
UKB_Yy^Y
D(Ix!G/
public static void main(String[] args) G\Hq/4
{ 4!%]fg}Um
new TestMethod(); i*tv,f.(
} 9{J?HFw*;
} _\AUQ{
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