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)); N:gstp
} )/N Xh'
for(int i=0;i<nEndPos.length-1;i++) xdTzG4
{ M'!!EQo
nEndPos = nStartPos[i+1]; hcp'+:
} ,n,7.m.D
nEndPos[nEndPos.length-1] = nFileLength; ;uWIl
} <x%my4M
} ~V$5m j
H@&"M%
(m =u;L"o
//启动子线程 $Bwvw)(%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tB(X`A.|
for(int i=0;i<nStartPos.length;i++) EBn:[2
{ n4d(`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dE9aE#o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \8>N<B)
nStartPos,nEndPos,i); BKP!+V/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?[>BssW
fileSplitterFetch.start(); )*L?PT
} MT#[ -M\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1 FIiX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;;"c+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T?}=k{C]
nEndPos = " + nFileLength); jQwg)E+o;
// fileSplitterFetch[nPos.length-1].start(); J`D<
;uo|4?E:\(
cF<DUr)Ve
//等待子线程结束 O6/=/-?N=c
//int count = 0; k3|9U'r!c
//是否结束while循环 T.Y4L
boolean breakWhile = false; zZ"')+7q&%
wCEfR!i
N@`9 ~JS
while(!bStop) v_F?x!
{ {~p %\
write_nPos(); x?k |i}Q
Utility.sleep(500); bA9dbe
breakWhile = true; c$Nl-?W
8w@jUGsc
;>hPHx
for(int i=0;i<nStartPos.length;i++) >a] s
{ H-y-7PW*~
if(!fileSplitterFetch.bDownOver) I:2jwAl
{ Q]koj!mMl
breakWhile = false; O7_NXfh|
break; K]azUK7
} ^J=txsx
} sAAIyPJts
if(breakWhile) 1~iBzPU2
break; /SM#hwFxJ&
"lj:bxM2C
=81Xt1,
//count++; T=KrT7
//if(count>4) I3=Sc^zz&V
// siteStop(); RoXOGVo
} r3lr`s`
Z"8cGN'
2OOj8JS
System.err.println("文件下载结束！"); V\lF:3C
} mp$II?hZ*
catch(Exception e){e.printStackTrace ();} Rn^N+3o'M
} #+Gs{iXr
t$ ~:C
;."{0gq
//获得文件长度 ,3TD $2};.
public long getFileSize() kR|DzB7
{ '`VO@a
int nFileLength = -1; ;iI2K/ 3
try{ /|^^v DL
URL url = new URL(siteInfoBean.getSSiteURL()); Jx[e{o)o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )uJ`E8>-
httpConnection.setRequestProperty("User-Agent","NetFox"); WQ`P^5e
20xGj?M
x-k/rZ
int responseCode=httpConnection.getResponseCode(); <5L`d}
if(responseCode>=400) @)B5^[4(;
{ ^rb7`s#G
processErrorCode(responseCode); R_&V.\e_
return -2; //-2 represent access is error d~s-;T
} \evgDZf
;Cpm3at
<^$b1<@
String sHeader; GdwHm
=7Gi4X%
fH{$LjH(
for(int i=1;;i++) xg!\C@$
{ VH*(>^OfF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5 `mVe0uI
//Utility.log(in.readLine()); i; uM!d}
sHeader=httpConnection.getHeaderFieldKey(i); ;Awzm )Q
if(sHeader!=null) ;{u#~d}
{ \}(-9dr
if(sHeader.equals("Content-Length")) )u:8Pv
{ 6q7Y`%j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iFT3fP'> 5
break; 4y)1*VU:
} jh!IOtf
} nr%^:u
else ,$*klod
break; o{,(`o.1O
} E 4(muhY
} {_D'\i(Y_
catch(IOException e){e.printStackTrace ();} BbhdGFG1
catch(Exception e){e.printStackTrace ();} 6iS+3+
gU$3Y#R
Z.19v>-c
Utility.log(nFileLength); SaScP
rV{e[fGd
N1+]3kt ~
return nFileLength; N1t:i? q&
} je0 ?iovY
pfIvBU?
Q 7?4GxMj
//保存下载信息（文件指针位置） 0;`PHNBq
private void write_nPos() Fsdn2{g8U
{ !T1i_
try{ $:P~21,
output = new DataOutputStream(new FileOutputStream(tmpFile)); cA^7}}?e
output.writeInt(nStartPos.length); XBBRB<l)
for(int i=0;i<nStartPos.length;i++) TMs\#
{ [r~lO@
// output.writeLong(nPos); L3Iz]D3s
output.writeLong(fileSplitterFetch.nStartPos); {=Y&q~:8v
output.writeLong(fileSplitterFetch.nEndPos); CF4y$aC#
} 7m$/.\5
output.close(); MYm6C;o$
} jP]'gQ!-w
catch(IOException e){e.printStackTrace ();} 8BdeqgU/_
catch(Exception e){e.printStackTrace ();} kF7Al]IgT
} 27gm_*
B)iJH
-4a&R=%p
//读取保存的下载信息（文件指针位置） YRXe j
private void read_nPos() tt91)^GdYa
{ od|.E$B
try{ vDL/PXNC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sRG3`>1
int nCount = input.readInt(); smNr%}_g
nStartPos = new long[nCount]; 6C5qW8q]u3
nEndPos = new long[nCount]; %?y`_~G
for(int i=0;i<nStartPos.length;i++) [!$>:_Vq/
{ c}cboe2
nStartPos = input.readLong(); /267Q;d C)
nEndPos = input.readLong(); EORAx
} w, wt<@}
input.close(); WNi<|A#T{
} #pK)
catch(IOException e){e.printStackTrace ();} Sn,z$-;h;
catch(Exception e){e.printStackTrace ();} Rx<F^J
} NoIdO/vy"
P$yJA7]j;%
e4P.G4
private void processErrorCode(int nErrorCode) gA*zFhGVS7
{ kDQXPp
System.err.println("Error Code : " + nErrorCode); 2y,wN"qH*
} ^6n]@4P
cPYQ<Y=
lUz@Em
//停止文件下载 bvKi0-
public void siteStop() YWdvL3Bgk,
{ _X/`4 G
bStop = true; )$i3j 1[;
for(int i=0;i<nStartPos.length;i++) D.}b<kDD
fileSplitterFetch.splitterStop(); lX7^LB
'{~ej:
v|z1nD!?]
} ,%^0 4sl
} )}v2Z3:
//负责部分文件的抓取 + u+fEg/A
**FileSplitterFetch.java ^~od*:
*/ bHNaaif}P
package NetFox; [8n4lE[)"
UYUdIIoL
|@F<ajlV
import java.io.*; Y_B(R
import java.net.*; j.*}W4`Q_
[d}1Cq=_
\~>#<@h
public class FileSplitterFetch extends Thread { UK/k?0
C09@2M'
5=\b+<pE
String sURL; //File URL R!ij CF\
long nStartPos; //File Snippet Start Position |V5H(2/nk
long nEndPos; //File Snippet End Position aDESO5
int nThreadID; //Thread's ID O!jCQ{ T
boolean bDownOver = false; //Downing is over :n4x}%
boolean bStop = false; //Stop identical FE.:h'^h
FileAccessI fileAccessI = null; //File Access interface K9iR>put
(A_9;uL^_
>E#4mm
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uNjy&I:
{ Q]C1m<x
this.sURL = sURL; ijfT!W
this.nStartPos = nStart; K[H$qJmPX
this.nEndPos = nEnd; Hl51R"8o
nThreadID = id; R !HL+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `7`iCYiTy
} d!cx%[
li?Gb1
W=/B[@3'
public void run() S6uBk"V!
{ lK0coj1+
while(nStartPos < nEndPos && !bStop) 9b>a<Z
{ (msJ:SG
.W\Fa2}%av
IN"qJ3<k
try{ E*zk?G|
URL url = new URL(sURL); Z3Y%VHB_F(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P_}$|zj7
httpConnection.setRequestProperty("User-Agent","NetFox"); wSGUNP9
String sProperty = "bytes="+nStartPos+"-"; 9j/B3CjW
httpConnection.setRequestProperty("RANGE",sProperty); (Y%}N(Jg
Utility.log(sProperty); EW)]75o{QF
6aL`^^
dJk.J9Z
InputStream input = httpConnection.getInputStream(); hk(^?Fp
//logResponseHead(httpConnection); :Fh*4 &Z
LF8B5<[O
ugz1R+f_4{
byte[] b = new byte[1024]; vhKD_}}aP
int nRead; 3't?%$'5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IlY,V
{ TX;|g1K
nStartPos += fileAccessI.write(b,0,nRead); h4U .wk
//if(nThreadID == 1) hM-qC|!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v?}/WKe+0
} MEE]6nU
Mppb34y
'yl`0,3wV
Utility.log("Thread " + nThreadID + " is over!"); -H{{
bDownOver = true; Kgcg:r:
//nPos = fileAccessI.write (b,0,nRead); `C3F?Lch
} ~be&T:7.
catch(Exception e){e.printStackTrace ();} `#~@f!';
} aDs[\'
} >PTq5pk
=d9%ce
~{J.br`
//打印回应的头信息 ?U&onGy
public void logResponseHead(HttpURLConnection con) mY-r:
{ l`d=sOB^
for(int i=1;;i++) umc!KOkL
{ 4JucNGv
String header=con.getHeaderFieldKey(i); /%~`B[4F
if(header!=null) FYzl-7!Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); % nR:Rc!
Utility.log(header+" : "+con.getHeaderField(header)); 7kO 1d{u6b
else K-K+%U
break; %k"-rmW
} I3$v-OiL
} 7l?-2I'c
&iTsuA/7
rkVZP!7!
public void splitterStop() F4*f_lP
{ +K&ze:-Z
bStop = true; hsi#J^n{
} =fm/l-P@
Mv_4*xVc
0&<{o!>k
} @qeI4io-n
!5ppA
cdk;HK_Ve.
/* qr:[y
**FileAccess.java lgU7jn
*//文件访问(定位，写) H}A67J9x
package NetFox; Oa{M9d,l
import java.io.*; ]^dXB0
I\":L
=r`>tWs
public class FileAccessI implements Serializable{ WFTTBUoH
<[(xGrEZV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )U5AnL
RandomAccessFile oSavedFile; 9n1O@~
long nPos; V<1dA\I"
L,n'G%
%ePInpb
public FileAccessI() throws IOException Ta~Ei=d^
{ bjbm"~
this("",0); w}+jfO9
} 5'6Oan7dL:
+YXyfTa
*PD7H9m
public FileAccessI(String sName,long nPos) throws IOException gmt`_Dpm$
{ Tk)y*y
oSavedFile = new RandomAccessFile(sName,"rw"); pX"f "
this.nPos = nPos; s %/3X\_
oSavedFile.seek(nPos); +hi!=^b]
} hCM+=]z"
@N34 Q-l
ho 4~-xmN
public synchronized int write(byte[] b,int nStart,int nLen) . F_pP2A
{ ZfoI7<?33
int n = -1; &!_>J0
try{ (|<}q-wO
oSavedFile.write(b,nStart,nLen); (;\JCeGA
n = nLen; CPAizS
} fE,\1LK4
catch(IOException e) p%8y!^g
{ / F9BbG{
e.printStackTrace (); V4iN2
} 0jG8Gmh!
4;y*y tY*
J&2cf#
return n; p v%`aQ]o{
} IOomBy:
wm_xH_{F
K '7M\:zy
} 5V8WSnO
>E6w,Ab
vT)FLhH6*
/* K<6)SL4
**SiteInfoBean.java 0.qnbDw_
*/ [s"xOP9R
package NetFox; AfB,`l`k
s&TPG0W
AKu]c-
public class SiteInfoBean { Igrr"NuDZ
2XNO*zbve
h:[%' htz
private String sSiteURL; //Site's URL /5pVzv+rm
private String sFilePath; //Saved File's Path wa2?%y_G
private String sFileName; //Saved File's Name 7\HjQ7__
private int nSplitter; //Count of Splited Downloading File :;HJ3V;
t,Ss3
LB$#] Z
public SiteInfoBean() ]?M3X_Mq
{//nSplitter的缺省值为5 N6EG!*
//default value of nSplitter is 5 }}G`yfs}r
this("","","",5); c>mTd{Abi
} v4OroG=^
#-W a3P
i_Ol vuy~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b9X"p*'p
{ b8@?fC+tm
sSiteURL= sURL; gwO]U=Y
sFilePath = sPath; +~Wg@
sFileName = sName; m -]E|
this.nSplitter = nSpiltter; $MhfGMk!'
O4t0 VL$
7wKT:~~oS3
} VN]70LFz*i
> &tmdE
'(fQtQ%
public String getSSiteURL() rrz^LD
{ @kBy|5
return sSiteURL; ~)vq0]MRg
} oR[-F+__
yI$KBx/]n
WstX>+?'
public void setSSiteURL(String value) 3:qn\"Hj
{ pV[SY6/
sSiteURL = value; _D.4=2@|l8
} <aSjK#
1K\zamBg
upi\pXv
public String getSFilePath() I'[gGK4F
{ p.)IdbC`B
return sFilePath; [+;>u|
} =/kwUjC?
S3Dmc\f
h\-3Y U
public void setSFilePath(String value) ?vh1 >1D
{ %^pm~ck!
sFilePath = value; |pgrR7G'
} vX30Ijm
l\tg.O~
yVfF *nG
public String getSFileName() vb.}SG>
{ }-/oL+j
return sFileName; 0(qtn9;=2
} H'a6] ]2
d RIuA)0s
}o[NB
public void setSFileName(String value) "*8>` 6E
{ Q{=DLm`
sFileName = value; 03Uj0.Z|7
} 4p<c|(f#
)kIZmQ|f1
Fa0Fl}L
public int getNSplitter() uxx(WS
{ Xx,Rah)X3
return nSplitter; s+0n0C
} T|k_$LH
pgd9_'[5
{Ri6975
public void setNSplitter(int nCount) 2=IZD `{!
{ s.$:.*k
nSplitter = nCount; 1$_|h@
} cB0"vbdO
} -J":'xCP!
Lrjp
rczwxWK
/* \%}w7J;
**Utility.java A=96N@m6
*/ +k;][VC[O
package NetFox; zD@RW<M
,8[R0wsBaz
?Gx-q+H
public class Utility { *JArR1J
O-(gkE
7hlzuZob+y
public Utility() K?@x'q1
{ O^Y@&S RrQ
R+# g_"1@p
+!/pzoWpE
} BD2Gv)?g
e'X"uH Xt.
//线程睡眠 "Wg5eML0
public static void sleep(int nSecond) {W'{A
{ NCp]!=uM;
try{ (j&7`9<5
Thread.sleep(nSecond); f?lnBvT|b
} nmw#4yHYy:
catch(Exception e) SoHw9FtS
{ J3 xi5S
e.printStackTrace (); ra F+Bt`
} ^!6T,7B B
} )O,+'w?
yRWZ/,9x
//日志 1}q(Pn2
public static void log(String sMsg) iw^"?:'%
{ 'tDVSj
System.err.println(sMsg); xzw2~(lo
} ZMEYF!jN
,8.zbr
I:UN2`*#
public static void log(int sMsg) \Icd>>)*
{ :!w;Y;L:+
System.err.println(sMsg); H,(4a2zx
} ~p{ fl?
} Mk/ZEyq^
U]Fnf?(
Va$JfWef
/* s+9b.
**TestMethod.java 0Wb3M"#9<
*/ YK V"bI
package NetFox; yK>s]65&
>mMmc!u>G
V9;O1
public class TestMethod { +7Qj%x\
<3 I0$?xL
B/K{sI
public TestMethod() Y'?{yx{
{ ///xx/weblogic60b2_win.exe 7#sb},J{
try{ `G2!{3UD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gmCB4MO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "|GX%>/
SiteFileFetch fileFetch = new SiteFileFetch(bean); r5Xi2!
fileFetch.start(); S~ZRqL7ZO
} {^@qfkZz^
catch(Exception e){e.printStackTrace ();} $yZ(ws
L[Y|K%;~
d[&Ah~,
} !}J19]\
84c[Z
+pjU4>)
public static void main(String[] args) jO5Wemqf
{ h5ZxxtGU
new TestMethod(); zfA"xD
} nE"0?VNW$
} J Sms \
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