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)); @&B!P3{f
} 9?c^~77
for(int i=0;i<nEndPos.length-1;i++) ,e_#
{ c3t8yifQ
nEndPos = nStartPos[i+1]; _q4m7C<
} ='>UKy[=
nEndPos[nEndPos.length-1] = nFileLength; Cw5K*
} O3: dOL/C
} DdO'
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;VRR=p%,
//启动子线程 5^/[]*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e_-/p`9
for(int i=0;i<nStartPos.length;i++) {jf~?/<
{ ptQ(7N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0z#kV}wE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9-6_:N>
nStartPos,nEndPos,i); -"H4brj;G
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O+j:L
fileSplitterFetch.start(); :n9^:srGZH
} H\bIO!vb
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~ }22Dvo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j #YFwX4.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J@iN':l-
nEndPos = " + nFileLength); 3Q)>gh*
// fileSplitterFetch[nPos.length-1].start(); nWu4HFi
elgQcJ99
`p|vutk)U
//等待子线程结束 >#|Yoc
//int count = 0; EPRs%(w`
//是否结束while循环 w\*/(E<:
boolean breakWhile = false; FJ"9Hs2
hspg-|R
Am $L
while(!bStop) F k;su,]_
{ CF_!{X_k}
write_nPos(); n#cN[C9
Utility.sleep(500); qT @IY)e
breakWhile = true; f tDV3If
k;7.qhe:
mO.U)tL[
for(int i=0;i<nStartPos.length;i++) I9>*Yy5RNS
{ q+~CA[H5K
if(!fileSplitterFetch.bDownOver) {Z.@-Tl_
{ 2A+,. S_!x
breakWhile = false; J3;KQ}F.I
break; n.RhA-O
} hh&y2#Io
} 5zOSb$;
if(breakWhile) B,,d~\
break; >,Z{wxzJ
-+|[0hpw
v1)6")8o+
//count++; Bnq\Gg
//if(count>4) yw!`1#3.
// siteStop(); qV,j)b3M
} w-Fk&dC69
GR `ncI$z
2z3A"HrlA
System.err.println("文件下载结束！"); f*Js= hvO
} [hbp#I~*[
catch(Exception e){e.printStackTrace ();} #57z-x[1
} 0+LloB
t@M] ec
gQ#T7
//获得文件长度 3~rc=e
public long getFileSize() cU|jT8Q4H
{ Hc|U@G
int nFileLength = -1; *pp1Wa7O
try{ ^^uD33@_
URL url = new URL(siteInfoBean.getSSiteURL()); +9CUnRv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |pSoBA9U
httpConnection.setRequestProperty("User-Agent","NetFox"); IoOnS)
!@k@7~i
MDt?7c
int responseCode=httpConnection.getResponseCode(); BxYA[#fd}
if(responseCode>=400) Xm'K6JH'
{ 1H7Q[ 2E
processErrorCode(responseCode); Dj"=kL0
return -2; //-2 represent access is error IxBO$2
} n4y6Ua9m{
%;$Y|RbmqE
_B FX5ifK
String sHeader; 38i,\@p`9$
a=VT|CX[
WEAXqDjM
for(int i=1;;i++) +Ob#3PRy
{ );H[lKy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >nEnX
//Utility.log(in.readLine()); s;$TX304
sHeader=httpConnection.getHeaderFieldKey(i); [)vwg`]
if(sHeader!=null) Cq;d2u0)o$
{ J?fh3RW9
if(sHeader.equals("Content-Length")) l}c2l'
{ mXj Ljgc}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5N<v'6&=
break; Z"Ni Y
} i]%"s_l
} olxP`iK
else S'p`ECfVMA
break; KBA%
} @A'1D@f#
} e/jM+%
catch(IOException e){e.printStackTrace ();} rd4'y~#S
catch(Exception e){e.printStackTrace ();} yt:V+qdv
5>Yd\(`K
gi@ji-10
Utility.log(nFileLength); q.km>XRk~
wJ*-K-
[{LnE:
return nFileLength; { BL1j
} IkNt! 2s_
uA`PZ|
ER1mA:8>E
//保存下载信息（文件指针位置） Q.dy $`\
private void write_nPos() N==_'`O1Q0
{ s/H"Ab
try{ 3eP0v
output = new DataOutputStream(new FileOutputStream(tmpFile)); W+C_=7_
output.writeInt(nStartPos.length); 8;&S9'ci
for(int i=0;i<nStartPos.length;i++) Vp"Ug,1
{ %ab)Gs
// output.writeLong(nPos); B/kn&^z$|~
output.writeLong(fileSplitterFetch.nStartPos); ,GP4I3D
output.writeLong(fileSplitterFetch.nEndPos); \&)W#8V
} [c[MQA0
output.close(); )Hm[j)YI
} #(g+jb0E
catch(IOException e){e.printStackTrace ();} #ic 2ofI
catch(Exception e){e.printStackTrace ();} 05I39/T%
} ey\{C`(__y
Ilu`b|%D
q)xl$*g
//读取保存的下载信息（文件指针位置） k&iScMgCTH
private void read_nPos() *oX]=u&
{ I4f
try{ yXo0z_ G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); M2P@ &
int nCount = input.readInt(); q}v04Yy,o
nStartPos = new long[nCount]; |abst&yp
nEndPos = new long[nCount]; |QNLO#$ -
for(int i=0;i<nStartPos.length;i++) 'Mx K}9
{ 7r[%|:
nStartPos = input.readLong(); &W<>^C2v
nEndPos = input.readLong(); Bd~cY/M
} 4S0++Hp4
input.close(); ^@*zH?Rx{
} RR"WO
catch(IOException e){e.printStackTrace ();} Y\Qxdq
catch(Exception e){e.printStackTrace ();} ])j|<W/
} \M"^Oe{Dy?
X>Xp&o
QXxLe*
private void processErrorCode(int nErrorCode) jvc?hUcLKT
{ '}pgUh_
System.err.println("Error Code : " + nErrorCode); ' raB
} iVi3 :7*
^HlLj#
%*6oUb
//停止文件下载 nB@iQxcz
public void siteStop() $:BK{,\
{ _[vdY|_
bStop = true; Lr}b,
for(int i=0;i<nStartPos.length;i++) ^A"lkV7
fileSplitterFetch.splitterStop(); ]pRfY9w
E?gu(\an@
y.*=Ww+
} kuj12
} KjwY'aYwr:
//负责部分文件的抓取 %][$y7
**FileSplitterFetch.java [X">vaa
*/ 1u"*09yZd
package NetFox; 2~&hstd%
5hH6G
AXh3LA
import java.io.*; L740s[,`o#
import java.net.*; 60aKT:KLC_
,8=`*
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public class FileSplitterFetch extends Thread { &<w[4z\
f*T)*R_
Y( $Ji12
String sURL; //File URL @"{'j
long nStartPos; //File Snippet Start Position 29iIG 'N
long nEndPos; //File Snippet End Position gF,[u
int nThreadID; //Thread's ID !&a;P,_Fb
boolean bDownOver = false; //Downing is over Z]aK'
boolean bStop = false; //Stop identical aq0iNbv@
FileAccessI fileAccessI = null; //File Access interface s@ 20#D
^?s~Fk_V
~C"k$;(n
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N$,/Q9h^
{ ;N$0)2w
this.sURL = sURL; &8Jg9#
this.nStartPos = nStart; dm,}Nbc91(
this.nEndPos = nEnd; (,Ja
nThreadID = id; qF{DArc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;naq-%'Sg
} NlF0\+h
rWFcIh5
{7=WU4$
public void run() ]~prR?
{ Y%fVt|
while(nStartPos < nEndPos && !bStop) 1qLl^DW
{ ~3'RW0
z#{0;t
$h 08Z
try{ Gin_E&%g
URL url = new URL(sURL); q[)q|R|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]|,q|c,
httpConnection.setRequestProperty("User-Agent","NetFox"); 5PGlR!^
String sProperty = "bytes="+nStartPos+"-"; dSe8vA!)
httpConnection.setRequestProperty("RANGE",sProperty); b.R!2]T]i^
Utility.log(sProperty); SLdN.4idK
Hbjb7Y?[
vnC<*k4&v
InputStream input = httpConnection.getInputStream(); RGl=7^M
//logResponseHead(httpConnection); qY$*#*Q
v@fe-T&0
O}K_l1
byte[] b = new byte[1024]; -t@y\vZF,
int nRead; b W=.K>|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3!.H^v?
{ 't|Un G
nStartPos += fileAccessI.write(b,0,nRead); .~.``a
//if(nThreadID == 1) pHen>BA[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RIy5ww}3|
} s&dO/}3uR]
MX!u$ei
"U%n0r2
Utility.log("Thread " + nThreadID + " is over!"); axK6sIxx
bDownOver = true; +mfe*'AU
//nPos = fileAccessI.write (b,0,nRead); Uvjdx(fY[a
} \~@[QGKN
catch(Exception e){e.printStackTrace ();} *xE"8pN/
} c=A(o
} jl.okWuiY
]#Vo}CVP
+Lm3vj_N
//打印回应的头信息 j+DE|Q&]I
public void logResponseHead(HttpURLConnection con) 3h9Sz8
{ ORGv)>C|
for(int i=1;;i++) bQ-Gp;]
{ E`Jp(gK9F
String header=con.getHeaderFieldKey(i); `fBG~NDw
if(header!=null) -}{%Q?rYj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qQfqlD<
Utility.log(header+" : "+con.getHeaderField(header)); Sl3KpZ
else Gb(C#,xbK
break; nG"tO'J6
} @+'c+
} DtzA$|Q}
{$EH@$./
g.64Id
public void splitterStop() D JLiZS
{ vkd[:CC
bStop = true; 9=t#5J#O
} N\9}\Rk@
3iE-6udCS
^FP} qW~;9
} ZCy`2Fir
3@^MvoC
tHrK~|
/* }.0Bl&\UK
**FileAccess.java ^)&Ly_xrU
*//文件访问(定位，写) A<4_DVd@@
package NetFox; +>JdYV<?0
import java.io.*; 9$Ig~W)
0:Ar|to$m
2R^O,Vu*W
public class FileAccessI implements Serializable{ s%eyW _
0B=[80K;8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 aSc{Ft/O
RandomAccessFile oSavedFile; 6!P`XTTE
long nPos; yGU .AM
<,\ `Psa)N
hf;S]8|F
public FileAccessI() throws IOException q5Fs)B
{ YiD-F7hf.*
this("",0); ]JOephX2R
} lB1#
p6`Pp"J_tr
z< z*Wz
public FileAccessI(String sName,long nPos) throws IOException 0y)}.'
{ o4$Ott%Wm
oSavedFile = new RandomAccessFile(sName,"rw"); gfi AK%
this.nPos = nPos; /\na;GI$
oSavedFile.seek(nPos); M70c{s`w5
} 94\t1fE
2ck4C/ h
Y[2Wt%2\6
public synchronized int write(byte[] b,int nStart,int nLen) &e5(Djz8t
{ (=1)y'.
int n = -1; U4Z[!s$
try{ MWiMUTZg3
oSavedFile.write(b,nStart,nLen); 2@vJ
n = nLen; n5|l|#c$N
} COR;e`%,
catch(IOException e) WzjL-a(
{ yQ9ZhdQS
e.printStackTrace (); Mtm/}I
} pe9@N9_5
d')-7C
gw"~RV0
return n; ][,4,?T7
} BT]ua]T+
0o;O`/x
O`WIkBV!
} >&OUGu|
#/|75 4]]
zrs<#8!Y_!
/* d{f@K71*
**SiteInfoBean.java -T7%dLHY
*/ b/t
package NetFox; } ^i b
p~K9 B-D
6R`Oh uN.>
public class SiteInfoBean { ` @8`qXg
XAPYpBgm
~4\,&HH
private String sSiteURL; //Site's URL VU|;:
private String sFilePath; //Saved File's Path Wqra8u#
private String sFileName; //Saved File's Name oBA`|yW{U
private int nSplitter; //Count of Splited Downloading File D==Mb~
FXV`9uq}Z
$J.T$0pFa
public SiteInfoBean() k@V#HC{t
{//nSplitter的缺省值为5 ,_D"?o
//default value of nSplitter is 5 rz%<AF Z
this("","","",5); \ p4*$
} -?<4Og[^
V >Hf9sZ
;#TaZN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l?/Y
{ !Vheq3"q/
sSiteURL= sURL; RW_q~bA9
sFilePath = sPath; 1S0pd-i
sFileName = sName; 4,G w#@
this.nSplitter = nSpiltter; +R6a}d/K
3$VxRz)
|9Yi7.
} `Gd$:qV
!g>.i`
]u#JuX
public String getSSiteURL() &.Q8Mi aT
{ 09S6#;N&
return sSiteURL; y,=du
} &3Z?UhH
:m'+tGs
vMla'5|l
public void setSSiteURL(String value) WZZ4]cC
{ 1zftrX~v!X
sSiteURL = value; ~9=aT1S|
} w8iR|TV
@*MC/fe
FB:<zmwR
public String getSFilePath() #z!^<,
{ aRJcSV
return sFilePath; Jq ]:<TQ
} ZDx@^P y
V-!"%fO.s
Kmz7c|
public void setSFilePath(String value) DNkWOY#{
{ eKN$jlg
sFilePath = value; Bfr'Zdw
} iWLa>z|,
nmFC%p)4
npp[@*~
public String getSFileName() 9bJQT'<R
{ (\a6H2z8l
return sFileName; tNIlzR-
} s%pfkoOY%
] asBd"
dQb.BOI)h
public void setSFileName(String value) N]N4^A'
{ Nt:9MG>1
sFileName = value; LfLFu9#:w
} ;heHefbvvd
x;\wY'
8K9$,Ii
public int getNSplitter() Ucdj4[/,h
{ T]T;$
return nSplitter; }_ mT l@*
} 4~z?"
?BA^YF
PX(pX>
public void setNSplitter(int nCount) 8|Y.|\
{ "YU{Fkl#j
nSplitter = nCount; |=a}iU8
} J#2!ZQE 3
} ? 1*m,;Z
:-`7Q\c}
"xRBE\B
/* oslJC$cy'
**Utility.java a`(a)9i
*/ =PHIpFIuk
package NetFox; 7piuLq+
!T,AdNa8
8}e,%{q
public class Utility { ul f2vD
hsKmnH@#
fV:4#j
public Utility() D4JLtB'=
{ TXXy\$
4Kwh?8.
WQNE2Q
} f:B>zp;N
;Lm=dd@S:
//线程睡眠 5kNzv~4B,;
public static void sleep(int nSecond) SLfFqc+n0
{ 'CZa3ux
try{ X|D!VX>#!
Thread.sleep(nSecond); l`-bFmpA
} u{N,Ib 8
catch(Exception e) ;6ecrQMw&
{ mo{MR:>)
e.printStackTrace (); ._9 n~=!
} R9rj/Co
} jjM\.KL]
OS|>t./U
//日志 C[!MS5
public static void log(String sMsg) wCf~O'XLw
{ {O<l[|Ip
System.err.println(sMsg); C:8_m1Y{
} :,b iyJt
{gNV[45
>gwz,{
public static void log(int sMsg) 0[?ny`Y
{ &UCsBqIY
System.err.println(sMsg); K_?W\Yg
} 38DT2<qC
} 0$+fkDf
G0O#/%%
Vm}%ttTC
/* #rO8Kf
**TestMethod.java XdLCbY
*/ #GDe08rOw
package NetFox; m'\2:mDu0
<<](XgR(
mkh"Kb*{
public class TestMethod { Ch$*Gm19Z
jcNT<}k C
'I;!pUfVp
public TestMethod() km^^T_ M/
{ ///xx/weblogic60b2_win.exe Ofm%:}LV
try{ n+lOb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V7G7&'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )irRO8
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y HSYu
fileFetch.start(); "8^5>EJWv
} u]u[(K5F
catch(Exception e){e.printStackTrace ();} 6hZ@;Q=b
G7--v,R1x
ZCKka0*
} bl_H4
y2]-&]&
ydw)mT44K
public static void main(String[] args) XU/QA [K
{ c|F[.;cR
new TestMethod(); XNQAi (!GS
} ,QzL)W7
} 7\*FEjRM]
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