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)); e&;e<6l&{
} i8V\x>9
for(int i=0;i<nEndPos.length-1;i++) EL`|>/[J
{ p[JIH~nb
nEndPos = nStartPos[i+1]; 4j=3'Z|
} -`I|=lBz{H
nEndPos[nEndPos.length-1] = nFileLength; U0_)J1Yp
} d}4NL:=&
} ;[::&qf
SvM\9
ZU`9]7"87B
//启动子线程 #"4ioTL2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; aDdGhB
for(int i=0;i<nStartPos.length;i++) =\< 7+nv
{ 3P6O]x<-?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Bib<ySCre
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @e)}#kN.
nStartPos,nEndPos,i); 8X,6U_>#a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @!P2f
fileSplitterFetch.start(); 5`.CzQVb
} G1z*e.+y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wtek5C^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VO:4wC"7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b]]8Vs)'
nEndPos = " + nFileLength); pJ] Ix *M
// fileSplitterFetch[nPos.length-1].start(); J,?#O#j
v8ap"9b
@PvO;]]%
//等待子线程结束 *DPX4P
//int count = 0; Y6v{eWtSn
//是否结束while循环 /A7( `l;6
boolean breakWhile = false; O=2|'L'h!
!1)aie+p6
vUpAW[[
while(!bStop) (L/>LZn|
{ _= v4Iz0
write_nPos(); AT"gRCU$4
Utility.sleep(500); (!nkv^]
breakWhile = true; uxf,95<g)
!rUP&DA
>1sa*Wf
for(int i=0;i<nStartPos.length;i++) {U=J>#@G
{ >38>R0k35
if(!fileSplitterFetch.bDownOver) ?#K.D vGJ
{ [KK |_
breakWhile = false; uE's&H
break; \(Sly&gL
} 8TP$?8l
} Nj>6TD81u
if(breakWhile) 7S{qo&j'
break; 2`f{D~w
{zb'Z Yz
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//count++; huC{SzXM
//if(count>4) FHOw ]"#
// siteStop(); K}l3t2uk
} 4eHSAN"$
|o5eG><
y74Q(
System.err.println("文件下载结束！"); DhM=q
} '8q3ub<\
catch(Exception e){e.printStackTrace ();} M|DMoi8x
} &O'W+4FAc
ukR0E4p
R:~aX,qR
//获得文件长度 O)dnr8*
public long getFileSize() /z-rBfdy^
{ V+`kB3GV
int nFileLength = -1; Clum m@z;#
try{ s>>&3jfM
URL url = new URL(siteInfoBean.getSSiteURL()); ?Q]&;5o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N1'`^ay$
httpConnection.setRequestProperty("User-Agent","NetFox"); eGEwXza 4
l?m"o-Gp3
qd0G sr}j
int responseCode=httpConnection.getResponseCode(); wsQnjT>
if(responseCode>=400) Dd?G4xUG
{ ,%9XG077
processErrorCode(responseCode); "|3I|#s
return -2; //-2 represent access is error ZG=]b%
} tyR?A>F4
}3*<sxw7<
^OY$ W
String sHeader; ^OV; P[
Dmh$@Uu#F
|xB`cSu(
for(int i=1;;i++) rp@:i _]
{ wC{sP"D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p.W7>o,[w
//Utility.log(in.readLine()); ]ae(t`\l^
sHeader=httpConnection.getHeaderFieldKey(i); MRpMmu
if(sHeader!=null) mV^w|x
{ -m`|Sq
if(sHeader.equals("Content-Length")) $J6 .0O
{ fJLl-H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K&[0`sH!
break; 1GN^uia7
} ]t0o%w
} ?\\wLZ
else ;u2[Ww~k
break; Y(,RJ&7
} Q`bXsH
} s,_+5ukv
catch(IOException e){e.printStackTrace ();} eCI'<^
catch(Exception e){e.printStackTrace ();} H>+/k-n-
goR_\b SU
.<t{saToU
Utility.log(nFileLength); (XOz_K6c%K
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m'2F#{
return nFileLength; ;<i u*a
} mu B Y
dC6>&@ VX
1:eWZ]B5"
//保存下载信息（文件指针位置） O8Mypv/C
private void write_nPos() j)@W1I]2#
{ ~|KqG
try{ @JSWqi>
output = new DataOutputStream(new FileOutputStream(tmpFile)); /o4_rzR?
output.writeInt(nStartPos.length); %/2 ` u
for(int i=0;i<nStartPos.length;i++) B>i%:[-e
{ r8(oTx
// output.writeLong(nPos); $@VJ@JAe
output.writeLong(fileSplitterFetch.nStartPos); <);j5)/
output.writeLong(fileSplitterFetch.nEndPos); =)bOteWM
} _L8&.=4]i
output.close(); )nHMXZ>Td
} HP*)^`6X
catch(IOException e){e.printStackTrace ();} yl>^QMmo
catch(Exception e){e.printStackTrace ();} Y5E0n(Z
} bAt!S
kgBkwp
U,b80%k:
//读取保存的下载信息（文件指针位置） $U,]c
private void read_nPos() _U}|Le@ e
{ zDYJe_m ~
try{ E`N`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >XZ2w_
int nCount = input.readInt(); 9ZOQNN<ex
nStartPos = new long[nCount]; f.ua,,P.
nEndPos = new long[nCount]; 7_Vd%<:
for(int i=0;i<nStartPos.length;i++) T \34<+n1N
{ ]>)}xfL &,
nStartPos = input.readLong(); pYCMJK-H
nEndPos = input.readLong(); T72Li"00
} z .lb(xQ
input.close(); ';eAaDM
} o<b
catch(IOException e){e.printStackTrace ();} tQj=m_
catch(Exception e){e.printStackTrace ();} [GyPwb-
} [GknE#p
4-O.i\1q
2s2KI=6
private void processErrorCode(int nErrorCode) lxTqGwx
{ (O ;R~Io
System.err.println("Error Code : " + nErrorCode); f[zKA{R
} %.[AZ>
=[4C[s
@ &c@
//停止文件下载 [9EL[}
public void siteStop() #)D$\0ag
{ +SV!QMIg
bStop = true; Pd:tRY+t/
for(int i=0;i<nStartPos.length;i++) 6mZpyt
fileSplitterFetch.splitterStop(); U&kdR+dB
#;2mP6a[
bN*zx)f
} Qm3RXO
} q+YK NXI
//负责部分文件的抓取 /\jRr7 Cd
**FileSplitterFetch.java v]drDVJ
*/ vO{[P#L}
package NetFox; gO~>*q &
n-9X<t|*?a
Ft2ZZ<As
import java.io.*; 1 xrmmK
import java.net.*; #$t93EI
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public class FileSplitterFetch extends Thread { $I@. <J*
kD+B8TrW
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String sURL; //File URL mnMY)-6C
long nStartPos; //File Snippet Start Position Q!Dr3x
long nEndPos; //File Snippet End Position d cht8nX7~
int nThreadID; //Thread's ID 4pu>f.
boolean bDownOver = false; //Downing is over ,J-YfL^x6*
boolean bStop = false; //Stop identical ">I50#bT
FileAccessI fileAccessI = null; //File Access interface eR1]<Z$W\
j"+R*H(#
Xo4K!U>TzZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8-vNXvl
{ WAw} ?&k
this.sURL = sURL; FCr>$
this.nStartPos = nStart; d7QWK(d
this.nEndPos = nEnd; *O-si%@]
nThreadID = id; F[|aDj@q e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c;7ekj
} v/Ei0}e6~
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public void run() tO QY./I
{ R75np^
while(nStartPos < nEndPos && !bStop) b!|c:mE9|
{ ^$O,Gy)V
hz+x)M`Y
b{d@:"
try{ ?To r)>A'
URL url = new URL(sURL); \xaK?_hv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ddjaM/.E
httpConnection.setRequestProperty("User-Agent","NetFox"); {@[z-)N7\,
String sProperty = "bytes="+nStartPos+"-"; *FUbKr0
httpConnection.setRequestProperty("RANGE",sProperty); bjJ212J
Utility.log(sProperty); wg,w;Gle
>'lte&
6d3-GMUQ
InputStream input = httpConnection.getInputStream(); rOy-6og
//logResponseHead(httpConnection); pEE.%U
&P{[22dQ
_gF )aE
byte[] b = new byte[1024]; 2^7VDqLc
int nRead; ',p`B-dw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {)0"?$C_H
{ t1YVE%`w
nStartPos += fileAccessI.write(b,0,nRead); "M.vu}~>
//if(nThreadID == 1) e'z[JG=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vN%SN>=L<
} Hh8)d/D
LN?W~^gsR
@nS+!t{
Utility.log("Thread " + nThreadID + " is over!"); W]rK*Dc
bDownOver = true; ^J]~&.l
//nPos = fileAccessI.write (b,0,nRead); dw!cDfT+
} .5zqpm
catch(Exception e){e.printStackTrace ();} LMrb 1lg$
} /r Hd9^Y
} ~sSlfQWMzy
=q(;g]e
b}9Ry"
//打印回应的头信息 viT/$7`AI
public void logResponseHead(HttpURLConnection con) yb#NB)+E@
{ G~I@'[ur
for(int i=1;;i++) ^U.8grA
{ <o";?^0Q
String header=con.getHeaderFieldKey(i); G.,dP+i
if(header!=null) A-&C.g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m]$!wp
Utility.log(header+" : "+con.getHeaderField(header)); g,!6,v@
else Lh6G"f(n
break; UHYnl]
} @""aNKA^r>
} R*D0A@
$4y;F]
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public void splitterStop() jd|? aK;(
{ 1O0o18'
bStop = true; u|.L73<j%
} wG4=[d
HgP9evz,0
PYYOC"$
} F`;oe[wfk
++Qg5FukR
+^ n\?!
/* ~*9 vn Z@
**FileAccess.java C#`VVtei
*//文件访问(定位，写) e.%` tK3J
package NetFox; V^WR(Q}
import java.io.*; wIIxs_2Q0c
ML!Zm[I9
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public class FileAccessI implements Serializable{ 't:|>;Wx
-(4)lw>U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Bkvh]k;F8
RandomAccessFile oSavedFile; @sRUl ,M;Z
long nPos; #wL}4VN
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Z> jk\[
public FileAccessI() throws IOException R87-L*9B^0
{ 8_6\>hW&
this("",0); T> cvV
} 5_@ u Be~
fJ_d,4
fGDR<t3yiQ
public FileAccessI(String sName,long nPos) throws IOException 2yk32|
{ SR@yG:~
oSavedFile = new RandomAccessFile(sName,"rw"); C~IsYdln
this.nPos = nPos; E^aHe
oSavedFile.seek(nPos); _Gv[ D
} hce *G@b
_zq"<Q c
&L[7jA'[J
public synchronized int write(byte[] b,int nStart,int nLen) #gzY _)E
{ y%A!|aBu
int n = -1; zyyt`
try{ 8.4 1EKr2
oSavedFile.write(b,nStart,nLen); \^O#)&5 V
n = nLen; .}W#YN$
} 'k[O?}
catch(IOException e) .:?X<=!S&t
{ MYgh^%w:
e.printStackTrace (); TxL;qZRY ^
} ?-mDvW
Gq_rZo(@
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return n; G9y 0;br
} wg<UCmfu!
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} J ik+t\A
egcJ@Of
"iFA&$\
/* i7g+8zd8d
**SiteInfoBean.java 4 [2^#t[
*/ : tKa1vL
package NetFox; HPT{83
u~MD?!LV
o4I&?d7;"
public class SiteInfoBean { M{#
ATq)8Rm\
. C_\xb
private String sSiteURL; //Site's URL 3QlV,)}
private String sFilePath; //Saved File's Path ?'F>DN
private String sFileName; //Saved File's Name t Dx!m~[
private int nSplitter; //Count of Splited Downloading File T8|aFoHCK
6- H81y3
E[N5vG<
public SiteInfoBean() L@> +iZSO
{//nSplitter的缺省值为5 3,qq\gxB
//default value of nSplitter is 5 ?U~}uG^
this("","","",5); -oGJPl{r
} @o&.]FZs
rG7S^,5o
6n9;t\'Gt
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2K/+6t}
{ B/#tR^R
sSiteURL= sURL; s':fv[%
sFilePath = sPath; WH Zz?|^
sFileName = sName; ('1k%`R%
this.nSplitter = nSpiltter; slSQ\;CDA
=Rnx!E
8ut:cCrmg
} C:C9swik"5
)*&I|L<1
:/e=J
public String getSSiteURL() " bHeNWZ
{ cI#2MjL
return sSiteURL; \VW&z:/*pZ
} *h ~Y=#`8*
F_Q,j]0
~r~~0|=
public void setSSiteURL(String value) Bsm>^zZ`YU
{ JM8s]&
sSiteURL = value; @&f3zq
} 6`LC(Nv%-n
F">>,Oc)U"
p_hljgOV
public String getSFilePath() |.D_[QI
{ o!Vs{RRu}
return sFilePath; ;0}8vs
} .F'fBT`$
j[/'`1tOe
5[WhjTo
public void setSFilePath(String value) B!jINOg
{ z~d\d!u1
sFilePath = value; #k%3Ag
} Ed/@&52z0
dvUBuY^[
1XZ|}Xz
public String getSFileName() "i$uV3d
{ x/$s:[0B#
return sFileName; (]BZ8GOx
} :=#*[H
\mZ\1wzn'{
+NRn>1]
public void setSFileName(String value) [P*3ld,,G%
{ Xq&x<td
sFileName = value; {aq\sf;i{
} |Iy55~hK`
pk'@!|g%=
0|X!Uw-Q%_
public int getNSplitter() LX.1]T*m`
{ eafy5vN[zX
return nSplitter; vx=I3o
} 7p}G!]`
+P6#7.p`Z
qR<
public void setNSplitter(int nCount) >Uvtsj#
{ h Ia{s)
nSplitter = nCount; 9frx60
} *qg9~/
} X|L8s$>
{Ny\9r
fmie,[
/* sZ-]yr\E"
**Utility.java c< gM
*/ Kq`Luf
package NetFox; *Kt7"J
~nb%w?vv
xtjTU;T
public class Utility { /#$bb4
<C6/R]x#
bi!4I<E>k
public Utility() L&ws[8-
{ 4:cbasy
w0~iGr}P
9G_=)8sOV
} ;JFE7\-mC
^g[\.Q
//线程睡眠 W<2%J)N<
public static void sleep(int nSecond) <E@7CG.=
{ UVu"meZX
try{ *wp'`3y}
Thread.sleep(nSecond); .Z&OKWL
} >^:g[6Sj
catch(Exception e) &7Ixf?e!K
{ 0P/A
e.printStackTrace (); (Wq9YDD@
} EyNI]XEj
} ^yK94U;<Gy
Vu\|KL|
//日志 V@>?lv(\
public static void log(String sMsg) 94APjqV6'
{ 8tA.d.8
System.err.println(sMsg); (%#d._j>fZ
} N/{A' Wd
.ET;wK
no?)GQ
public static void log(int sMsg) 6xL=JSi~
{ 'VJMi5Y(-
System.err.println(sMsg); ?RpT_u
} #EHBS~^
} c;U\nC<Y
9^a>U(,
+{hxEDz
/* EE}NA{b
**TestMethod.java !a~x|pjJ
*/ WKah$l
package NetFox; 2zFdKs,
1r~lh#_8
c+a f=ac
public class TestMethod { T@yH.4D
\=N tbBL$[
l42m81x"
public TestMethod() ik$wS#1+L
{ ///xx/weblogic60b2_win.exe On'3K+(_
try{ |Y'$+[TE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J`RNik*>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H<1?<1^
SiteFileFetch fileFetch = new SiteFileFetch(bean); _5`M( ;hL2
fileFetch.start(); E<\\'VF
} NWAF4i&$
catch(Exception e){e.printStackTrace ();} BB%(!O4Dl
(VOKa
;~1r{kXxA"
} pRU6jV 6e)
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Hzj*X}X#K
public static void main(String[] args) c%Gz{':+
{ /6q/`vx@
new TestMethod(); ~zm/n,Epb
} Iyc')\W&
} `S~u4+y]
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