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)); Z!)~?<gcq:
} ilA45@
for(int i=0;i<nEndPos.length-1;i++) 0NXH449I=
{ 5% 2A[B
nEndPos = nStartPos[i+1]; l4OrlS/5
} yD7BZI xW
nEndPos[nEndPos.length-1] = nFileLength; ;-+q*@sa]
} or/gx3
} 1~5DIU^
qN $t_
A&Y5z[p
//启动子线程 ;mkkaW,D*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x HRSzYn$
for(int i=0;i<nStartPos.length;i++) ,`@pi@<"#
{ 7?$?Yu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R4m{D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5*AXL.2ih
nStartPos,nEndPos,i); nHseA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i[v4[C=WB!
fileSplitterFetch.start(); hF%M!otcJ-
} rtV`Q[E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KK){/I=z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Fx9-A8oIR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E/P~HE{
nEndPos = " + nFileLength); O>~,RI!
// fileSplitterFetch[nPos.length-1].start(); <+`%=r)4
WsI`!ez;D
!@xO]Jwv
//等待子线程结束 g!'R}y
//int count = 0; >|$]=e,Z
//是否结束while循环 $[ {5+*
boolean breakWhile = false; g7\=
&Y{^yb
}LzBo\
while(!bStop) M/zO|-j&
{ ,_2-Op
write_nPos(); Xz$4cI#n:
Utility.sleep(500); {>]\<
breakWhile = true; :xd;=;q5
*g/klK
i0vm00oT
for(int i=0;i<nStartPos.length;i++) L, JQ\!c
{ G]^[i6PQs
if(!fileSplitterFetch.bDownOver) T(b9b,ov)
{ @60D@Y
breakWhile = false; C]`uC^6g
break; *l2`- gbE
} c8l>OS5i3_
} j4.wd RK
if(breakWhile) "6B7EH
break; fz&B$1;8
-@orIwA&
%TB(E<p`
//count++; I6>J.6luF9
//if(count>4) .iXN~*+g
// siteStop(); R><g\{G]
} }A#IBqf5
g@.$P>Bh
0> f!S` *
System.err.println("文件下载结束！"); h9vcN#22D
} K7 e~%mY
catch(Exception e){e.printStackTrace ();} [a=exK
} |Splbsk
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rQ;w{8J\t
//获得文件长度 5)[~ T2j!
public long getFileSize() HA6tGZP*L
{ i"8mrWb
int nFileLength = -1; LP<A q
try{ _plK(g-1J%
URL url = new URL(siteInfoBean.getSSiteURL()); zLI0RI.Pe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }z3j7I
httpConnection.setRequestProperty("User-Agent","NetFox"); g'0CYY
+#O+%!
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int responseCode=httpConnection.getResponseCode(); VYvfx
if(responseCode>=400) K_7pr~D]@r
{ %y1!'R:ZW
processErrorCode(responseCode); jc^QWK*q
return -2; //-2 represent access is error t@q'm.:uw<
} +H)'(<
Q8p6n
7_0p& 3
String sHeader; |)-kUu
vOQ%f?%G\
@Nu2 :~JO
for(int i=1;;i++) Z;BS@e
{ |P|B"I<?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;b~ S/
//Utility.log(in.readLine()); PwY/VGT
sHeader=httpConnection.getHeaderFieldKey(i); tFN >]`Z
if(sHeader!=null) dzVi ~wt_&
{ @MW@mP)#
if(sHeader.equals("Content-Length")) +-9vrEB
{ Q&9yrx.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P7x;G5'.
break; S-Uod y
} @"@a70WHk
} .~z'm$s1o
else 96=<phcwN[
break; gI+8J.AG=
} TP }a9-9?
} fi+}hGj(r
catch(IOException e){e.printStackTrace ();} Nw;qJ58@
catch(Exception e){e.printStackTrace ();} 0|3I^b
8tY>%A~^z
7& M-^Ev
Utility.log(nFileLength); SI(f&T(
|,8z"g
-<iP$,bq72
return nFileLength; @[GV0*yz$
} e#Tv5O
+pofN-*%
m]p{]6h
//保存下载信息（文件指针位置） Q*ITs!~Z
private void write_nPos() ;>6< u.N
{ wxN)dB
try{ GES}o9?#
output = new DataOutputStream(new FileOutputStream(tmpFile)); qJey&_
output.writeInt(nStartPos.length); Di9RRHn&q
for(int i=0;i<nStartPos.length;i++) j=\h|^gA
{ WI8}_){ d
// output.writeLong(nPos); N0`9/lr|
output.writeLong(fileSplitterFetch.nStartPos); R@e'=z[%1
output.writeLong(fileSplitterFetch.nEndPos); l|5 h
} m</m9h8
output.close(); e`*}?N4d
} ]#/nn),Z
catch(IOException e){e.printStackTrace ();} t,/ G
catch(Exception e){e.printStackTrace ();} W4^L_p>Tm^
} ;vn0%g
kY0HP a
$|4@Zx4vf
//读取保存的下载信息（文件指针位置） $vn6%M[
private void read_nPos() 3JazQU
{ 2e48L677-
try{ d;i|s[6ds`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K<JzIuf&
int nCount = input.readInt(); ts]e M1;
nStartPos = new long[nCount]; s%[F,hQRk
nEndPos = new long[nCount]; |/.J{=E0K
for(int i=0;i<nStartPos.length;i++) ]a3$hAcj6"
{ AFLtgoXn:
nStartPos = input.readLong(); q0sf\|'<}
nEndPos = input.readLong(); dFg>uo
} tV}!_
input.close(); JK,MK|
} #w$Y1bjn
catch(IOException e){e.printStackTrace ();} V&Y`?Edc
catch(Exception e){e.printStackTrace ();} `Rq=:6U;3
} _nGx[1G( 5
qGk+4 yC
R2bqhSlF
private void processErrorCode(int nErrorCode) _&KqmQ8$7
{ Im]@#X
System.err.println("Error Code : " + nErrorCode); =H95?\}T[
} WtSs:D
z]7 WC
r>mBe;[TX
//停止文件下载 b?wrOS
public void siteStop() Mz+I YP`L
{ ULx:2jz
bStop = true; 1" '3/MFQ8
for(int i=0;i<nStartPos.length;i++) Ple.fKu
fileSplitterFetch.splitterStop(); n ]%2Kx
B|`?hw@g+
5epI'D
} a@}.96lStD
} 8$FH;=
//负责部分文件的抓取 Iix,}kzss
**FileSplitterFetch.java U~G7~L &m
*/ "8za'@D"f
package NetFox; D%>Bj>xQD
i4D(8;
bpu`'Vx
import java.io.*; q<RjAi
import java.net.*; )\wkVAm
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{X,%GI
public class FileSplitterFetch extends Thread { sG g458
p.8bX
$<*) 5|6
String sURL; //File URL B4s$| i{D
long nStartPos; //File Snippet Start Position n,T &n
long nEndPos; //File Snippet End Position !$)reaS
int nThreadID; //Thread's ID HZrA}|:h
boolean bDownOver = false; //Downing is over J+D|/^
boolean bStop = false; //Stop identical 7w )?s@CD
FileAccessI fileAccessI = null; //File Access interface d<c29Y
G?4@[m
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tFU4%c7V
{ $v>q'8d
this.sURL = sURL; A;cA|`b
this.nStartPos = nStart; kD#T_d
this.nEndPos = nEnd; VoCg,gow
nThreadID = id; 'h$:~C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &X4anH>O
} b42%^E
;@+|]I
vNi;)"&*
public void run() ^} {r@F
{ lKbWQ>
while(nStartPos < nEndPos && !bStop) fECV\Z
{ j26i+Z
=7!s8D,[
rfV'EjiM}
try{ (Jp~=6&lKf
URL url = new URL(sURL); Y7GsL7I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =DwLNyjU4
httpConnection.setRequestProperty("User-Agent","NetFox"); YNr5*P1
String sProperty = "bytes="+nStartPos+"-"; 082}=Tsx
httpConnection.setRequestProperty("RANGE",sProperty); 2EgvS!"
Utility.log(sProperty); `IN!#b+Eo
?K$&|w%{3
FNGa4
InputStream input = httpConnection.getInputStream(); WcmX"{
//logResponseHead(httpConnection); ^y,h0?Z9
aEf3hB*~
fW= N
byte[] b = new byte[1024]; dv+Gv7&2/
int nRead; x,nl PU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LhG\)>Y%
{ {S0-y
nStartPos += fileAccessI.write(b,0,nRead); av'DyNW\
//if(nThreadID == 1) CU=sQfE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D5gj*/"
} `%YMUBaI
|s3;`Nxu7
m|NZ093d
Utility.log("Thread " + nThreadID + " is over!"); u|KjoO
bDownOver = true; Na@bXcz)
//nPos = fileAccessI.write (b,0,nRead); Z?P^Y%ls
} jCY~Wc
catch(Exception e){e.printStackTrace ();} +~n:*\
} 9]Jv >_W*
} e&sH<hWR
<F^9ML+'
\Zf=A[
//打印回应的头信息 ByqVNz0L
public void logResponseHead(HttpURLConnection con) QC'Ru'8S
{ izSX
for(int i=1;;i++) ~vTwuc\(H
{ eEXNEgbn
String header=con.getHeaderFieldKey(i); cB&_':F
if(header!=null) -9vNV:c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B/X$ZQ0
Utility.log(header+" : "+con.getHeaderField(header)); Y" =8wNbr
else 97Dq;
break; *VsGa<V
} ,h=a+ja8
} ,^bgk -x-
:2lpl%/
<M9NyD`
public void splitterStop() ?22U0UF
{ s AFn.W
bStop = true; NL]_;\ h
} K/9Jx(I,qL
Cl'$*h
]QlW{J
} *I :c@iCNJ
7V%P
-sJ1q^;f@
/* OROvy
**FileAccess.java $e1.y b%
*//文件访问(定位，写) 9(t(sP_
package NetFox; ;6@sC[
import java.io.*; ezw*Lo!
LqYyIbsvf
gaN/ kp
public class FileAccessI implements Serializable{ uD/@d'd_4L
z5gVP8*z5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 UvGxA[~2+
RandomAccessFile oSavedFile; JDf>Qg{
long nPos; 7:B/?E
3;buC|ky
_-BP?'lN
public FileAccessI() throws IOException +a39 !j 1_
{ 3IRur,|'
this("",0); OxDqLX
} Dtd~}-_Q
6):1U
N!ihj:,
public FileAccessI(String sName,long nPos) throws IOException LEM%B??&5z
{ a4UwhbH
oSavedFile = new RandomAccessFile(sName,"rw"); Sm<*TH!\n_
this.nPos = nPos; ~AjPa}@ f
oSavedFile.seek(nPos); ]AQ}_dRi=
} fY^CIb$Y
M(L6PyEa!Y
# bHkI~
public synchronized int write(byte[] b,int nStart,int nLen) QM8Ic,QFvo
{ R*vQvO%)h
int n = -1; ,c"J[$i$
try{ VwH|ed$
oSavedFile.write(b,nStart,nLen); d<d3j9u(#
n = nLen; CNb(\]
} @'>RGaPV
catch(IOException e) 46]BRL2 G
{ YyYZD{^
e.printStackTrace (); ^"O>EY':
} ^R:&c;&,
7tWC<#
W8Ssv
return n; ^vMlRt;
} M6&=-
<y8oYe_!
Tr_gc~
} $F^VtCx2&
F%<*a,m6g
!`%j#bv
/* XA<h,ONE?
**SiteInfoBean.java M?YNK]
*/ 5IUdA?
package NetFox; "x R6~8
]+Lr'HF
Eu' ;f_s
public class SiteInfoBean { ]7}!3m
~-Kx^3(#
2b7-=/[6
private String sSiteURL; //Site's URL 9;Z{++z
private String sFilePath; //Saved File's Path 1q(Qr h
private String sFileName; //Saved File's Name 3F]Dh^IR9
private int nSplitter; //Count of Splited Downloading File 8!|vp7/
)YgntI@
F oC $X
public SiteInfoBean() |;NfH|43;
{//nSplitter的缺省值为5 *-PjcF}Y
//default value of nSplitter is 5 e4Nd
this("","","",5); ^7\kvW
} x?o#}:S
g;=VuQuP|
xI{fd1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R_B0CM<!
{ o)XrC
sSiteURL= sURL; !.,J;Qt
sFilePath = sPath; OW#0$%f
sFileName = sName; 6&0@k^7~
this.nSplitter = nSpiltter; 5@+?{Cl
8<"g&+T
d)1gpRp
} W]/J]O6
;*Vnwt A
qdI%v#'M
public String getSSiteURL() _!1LV[x!s
{ F}{%*EJ
return sSiteURL; ( jU $
} ymxA<bICS8
UBuh'?j
]?+i6 [6U
public void setSSiteURL(String value) eMnK@J
{ mP\V.^
sSiteURL = value; QNOdt2NN
} vY_[@y
`2]0 X#R
pk9Ics;y
public String getSFilePath() 1v|-+p42
{ VA[EY`8
return sFilePath; Hc'Pp{| X
} @U8u6JNK'
:.ZWYze
h"+7cc@
public void setSFilePath(String value) *Z"`g %,;
{ dscah0T
sFilePath = value; H2BRId
} -y|J_;EG
)XN%pn
d~qQ_2M[G
public String getSFileName() 9no<;1+j,
{ WF`%7A39Af
return sFileName; E>s+"y
} zQulPU
Zpg;hj5_
enJ;#aA
public void setSFileName(String value) Qwpni^D8j
{ pi"M*$
sFileName = value; AMjr[!44 @
} :W,S
={;pg(
't`h?VvL
public int getNSplitter() y/\b0&
{ ~g/"p`2-N
return nSplitter; A9b(P[!]T:
} <b H*f w
w{aGH/LN
3h:~NL
public void setNSplitter(int nCount) jzV"(p!
{ 73rme,
nSplitter = nCount; r{v3XD/
} lo>9 \ Po
} \85%d0@3
neM.M)0
nDdY~f.B
/* ~'lT8 n_
**Utility.java IOZw[9](+
*/ Ztmh z_u7
package NetFox; =!q]0#
F2}Fuupb.
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public class Utility { 7JBs7LG
aC[G_ACwc
t$nJmfzm
public Utility() k)-+ZmMOh
{ 0RA#Y(IR
ISC>]`
`[5xncZ-
} {.$7g8]I
tV(iC~/
//线程睡眠 -:%QoRCy
public static void sleep(int nSecond) ((A@VcX
{ 0a89<yX
try{ "O>~osj
Thread.sleep(nSecond); g)czJ=T2
} "b`#RohCi
catch(Exception e) dh`s^D6Q>
{ [T_[QU:A
e.printStackTrace (); e#Ao]gc
} jdG2u p
} HSNj
;SU<T^a
//日志 ^slIR!L
public static void log(String sMsg) LSc^3=X
{ 8_!qoW@B
System.err.println(sMsg); Y^Buz<OiG
} ?I^$35
h@R n)D
HjA~3l7
public static void log(int sMsg) E~}H,*)
{ M,JwoKyg
System.err.println(sMsg); }PK4 KRn
} P1[.[q/-e
} DGGySO6=$e
5go)D+6s
zgjgEhnvU
/* s U`#hL6;
**TestMethod.java .5; JnJI
*/ 8J'5%$3u
package NetFox; =? !FO'zt"
(E0WZ$f}
)q_,V"
public class TestMethod { $V3If
L?nhm=D
MXaik+2
public TestMethod() t#P7'9Se8
{ ///xx/weblogic60b2_win.exe |.Vgk8oTl
try{ v];YC6shx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8i] S[$Fc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (Z>?\iNJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); mh"PAp
fileFetch.start(); LAc60^t1
} u_WUJ_
catch(Exception e){e.printStackTrace ();} zqj|$YNC
Fxa{ 9'99
,|RKM
} i}8OaX3x
(.N n|lY<i
E'{:HX
public static void main(String[] args) @lDnD%vZ`
{ n>u_>2Ikkj
new TestMethod(); t+A*Ws*o
} ^ulgZ2BQ|
} /95z1e
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