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)); QtvYv!
} [HCAmnb
for(int i=0;i<nEndPos.length-1;i++) detwa}h[0
{ f4L`.~b'hb
nEndPos = nStartPos[i+1]; TEDAb>
} rj6#1kt
nEndPos[nEndPos.length-1] = nFileLength; $H+VA@_
} e["2QIOe
} LBF 1;zjK
_E@:O+K
gn3jy^5
//启动子线程 Nbp!teH6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?B:a|0pf
for(int i=0;i<nStartPos.length;i++) 'Ysx=
{ R'S0 zp6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hAHq\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 97ql5
nStartPos,nEndPos,i); Z!U)I-x&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C+|b1/N-
fileSplitterFetch.start(); T0&f8
} @xB*KyUW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sJ]taY ou
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;A#`]-i C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [,TkFbDq"J
nEndPos = " + nFileLength); JwJ7=P=c
// fileSplitterFetch[nPos.length-1].start(); PssMTEf
7EXI6jGJ|
)c8j}
//等待子线程结束 otk}y8
//int count = 0; U#3J0+!
//是否结束while循环 sP ls zC[
boolean breakWhile = false; +|tC'gCnV
N5 $c]E
=+AS/Jq
while(!bStop) Vb9',a?#n
{ B, 9w0
write_nPos(); \?jeWyo
Utility.sleep(500); WD1G&5XP
breakWhile = true; ,Jd ',>3
W^s ;Bi+Nw
)n,P"0
for(int i=0;i<nStartPos.length;i++) zA[0mkC?$
{ %rxO_
if(!fileSplitterFetch.bDownOver) H/Llj.-jg
{ g&`pgmUX
breakWhile = false; fJ ,1Ef;Z
break; j\m_o% 4
} _)\c&.p]f
} s>^dxF!+
if(breakWhile) e[8LmuIZ
break; v'e[GB0
;X?mmv'
clk[/'1
//count++; ,mj@sC>
//if(count>4) ~q~MoN<R
// siteStop(); w+N> h;j
} aXL{TD:]
{RF-sqce
zD<or&6
System.err.println("文件下载结束！"); G_SG
} Qci4J
catch(Exception e){e.printStackTrace ();} i F+vl]
} n/h,Lr)Z
f aLtdQi
b?Ki;[+O
//获得文件长度 {Lm~r+ U
public long getFileSize() &\Amn?Iq
{ 4T=u`3pD7l
int nFileLength = -1; 6,9o>zT%H
try{ ~j<+k4I~
URL url = new URL(siteInfoBean.getSSiteURL()); 3"P }n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5sb\r,kW
httpConnection.setRequestProperty("User-Agent","NetFox"); eQ&ZX3*}
. Z%{'CC
3K_A<j:
int responseCode=httpConnection.getResponseCode(); PTEHP
if(responseCode>=400) f-%NaTI
{ [w -l?
processErrorCode(responseCode); KjQR$-
return -2; //-2 represent access is error v.]Q$q^
} l\sU
3JVK
V<j.xd7
String sHeader; ,13Lq-
;f"0~D2
Yboiwy,n
for(int i=1;;i++) PP!SK2u"L
{ t1%_DPD%W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qs QNjt
//Utility.log(in.readLine()); +Xemf?
sHeader=httpConnection.getHeaderFieldKey(i); T,VY.ep/
if(sHeader!=null) &cu lbcz
{ )4&cph';
if(sHeader.equals("Content-Length")) -UD\;D?$
{ qv@$ZLR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ; k)@DX
break; 3:C oZ
} *Q,0W:~-
} z-b*D}&
else K=,F#kn
break; 3#TV5+x*"`
} GxKqD;;u?=
} R[;zX(y
catch(IOException e){e.printStackTrace ();} V#`fs|e;y
catch(Exception e){e.printStackTrace ();} sxt-Vs7+6
*;Ed*ibf
(e[}/hf6
Utility.log(nFileLength); 8:/e GM
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return nFileLength; L\#<JxY$p
} 3l#IPRn9AO
uxzze~_+C
qk;{cfzHA
//保存下载信息（文件指针位置） xa pq*oj
private void write_nPos() )lZp9O
{ dx+hhg\L
try{ $]/Zxd
output = new DataOutputStream(new FileOutputStream(tmpFile)); jb^N|zb
output.writeInt(nStartPos.length); oDU ;E
for(int i=0;i<nStartPos.length;i++) g2T -TG'd
{ [!U?}1YQ
// output.writeLong(nPos); .;*s`t
output.writeLong(fileSplitterFetch.nStartPos); - h9?1vc7
output.writeLong(fileSplitterFetch.nEndPos); .3MIcj=p
} ,Y>Bex_v
output.close(); 7IjQi=#:
} )-`;1ca)s
catch(IOException e){e.printStackTrace ();} >J>b>SU=-
catch(Exception e){e.printStackTrace ();} yn/rW$
} %,k][V
^)W[l!!<)
()3O=!
//读取保存的下载信息（文件指针位置） iX4Iu3
private void read_nPos() z~>pVs
{ |K|h+fgG6*
try{ g'|MA~4yB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3dRr/Ilc
int nCount = input.readInt(); cJL'$`gWf
nStartPos = new long[nCount]; I;1lX L
nEndPos = new long[nCount]; ?A )hN8
for(int i=0;i<nStartPos.length;i++) &[;HYgp
{ 6A=8+R'`F
nStartPos = input.readLong(); 1M}&ZH
nEndPos = input.readLong(); :G<E^<M\)^
} !1G."fo
input.close(); S!sqbLrBn
} W<E47
catch(IOException e){e.printStackTrace ();} h@LHRMO
catch(Exception e){e.printStackTrace ();} q|LDo~H
} Co3:*nbRv
17OH]
4~N[%>zJ
private void processErrorCode(int nErrorCode) C|o`k9I#
{ tT79p.z B
System.err.println("Error Code : " + nErrorCode); rrCNo^W1
} wW/7F;54
P:N1#|g
0s>/mh;
//停止文件下载 |a#f\
public void siteStop() ;Yg{zhJX~
{ -^ C=]Medl
bStop = true; [V) L
for(int i=0;i<nStartPos.length;i++) u3o#{~E/#
fileSplitterFetch.splitterStop(); _Y[jyD1>
56Vb+0J'
G2^et$<{uU
} 4NdN<#Lr
} jr3ti>,xV
//负责部分文件的抓取 wWp(yvz
**FileSplitterFetch.java =lVK IW
*/ +|ycvHd
package NetFox; _BDK`D
+tD[9b! m
hsw9(D>jp
import java.io.*; e A}%C.ZR
import java.net.*; O1`9Y}G(r
?Sb8@S&J
"hdvHUz
public class FileSplitterFetch extends Thread { ~wVd$%7`
9,^_<O@Q
Y!T %cTK)a
String sURL; //File URL MX ;J5(Ae
long nStartPos; //File Snippet Start Position FEJ~k1z
long nEndPos; //File Snippet End Position EMc;^ d
int nThreadID; //Thread's ID DK oN}c
boolean bDownOver = false; //Downing is over "kA*Vc#
boolean bStop = false; //Stop identical O/!bG~\Y
FileAccessI fileAccessI = null; //File Access interface Tr#V*.x
5P'p2x#U
c-Pw]Ju
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +L5\;
{ e0$=!QlPr
this.sURL = sURL; rgOfNVyJG<
this.nStartPos = nStart; STJJU]H
this.nEndPos = nEnd; > z^#
nThreadID = id; HdLH2+|P;D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <2nZ&M4/s{
} 2 6>ZW4Z
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''kS*3
public void run() =Z+nX0qF
{ 7YAIA%8
while(nStartPos < nEndPos && !bStop) LB.co4
{ "hQ_sgz[Z
o'$jNciOW
yA3wtm/?
try{ 8Y#\xzod
URL url = new URL(sURL); CV{r5Sye
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0JD~M\-!^a
httpConnection.setRequestProperty("User-Agent","NetFox"); <Tot|R;
String sProperty = "bytes="+nStartPos+"-"; G\a8B#hg
httpConnection.setRequestProperty("RANGE",sProperty); ,<Q~b%(3
Utility.log(sProperty); wm+})SOX9
G5FaYL.7
ZKdeB3D
InputStream input = httpConnection.getInputStream(); gp-T"l
//logResponseHead(httpConnection); nIvJrAm4k
Z'k|u4ZC
5H9r=a
byte[] b = new byte[1024]; d|iy#hy"_
int nRead; Q*XE h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q}FVzahv
{ aBzszp]l+
nStartPos += fileAccessI.write(b,0,nRead); @+WQ ^
//if(nThreadID == 1) -&e92g&n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [JaS??ig
} wlPx,UqZ
qSejLh6
/N-_FMl?
Utility.log("Thread " + nThreadID + " is over!"); ,Hgc-7g@Y
bDownOver = true; W k}AmC
//nPos = fileAccessI.write (b,0,nRead); X.TI>90{
} nJbbzQ,e
catch(Exception e){e.printStackTrace ();} (S^8UV
} Ou>vX[{
} )}L??|#
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~j'l.gQb
//打印回应的头信息 <s@-:;9~
public void logResponseHead(HttpURLConnection con) O,.!2wVrN
{ I_q~*/<h
for(int i=1;;i++) ')N{wSM9Ft
{ A$WZF/x
String header=con.getHeaderFieldKey(i); ~xIjF1Z
if(header!=null) d` Sr4c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +B|7p9qy
Utility.log(header+" : "+con.getHeaderField(header)); 28OWNS M=
else :5yV.7
break; %AW4.3()8
} n$:IVX"2b
} "+uNmUUnm
Ap$y%6
> MG>=A
public void splitterStop() UgN28YrW
{ Ux2U*a;
bStop = true; b5:op@V
} wl1m*`$
Yh)Isg|0>
:L 3&FA
} |/ }\6L]
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1h7+@#<:a
/* ]/cd;u
**FileAccess.java vOgC>_x7
*//文件访问(定位，写) *x>3xQq&
package NetFox; j(#%tIv
import java.io.*; ]P[%Mhg^
0ji q-3V)
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public class FileAccessI implements Serializable{ V|>oGtt7
gLsU:aeCT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fj,m
RandomAccessFile oSavedFile; KL'zXkS
long nPos; <:|3rfm#
{k(eNr,
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public FileAccessI() throws IOException 2ij# H ;
{ w-$[>R[hw
this("",0); 1=2^90
} u z\0cX_
>`jU`bR@
T5O _LCIws
public FileAccessI(String sName,long nPos) throws IOException NcM>{{8
{ bY~@}gC**@
oSavedFile = new RandomAccessFile(sName,"rw"); rx:z#"?I
this.nPos = nPos; bqx0d=Z~[
oSavedFile.seek(nPos); V|MY!uV
} OJ4SbI
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xdy^^3"
public synchronized int write(byte[] b,int nStart,int nLen) smQVWs>
{ _;RVe"tR#
int n = -1; {I{:GcS
try{ $ex!!rqN|
oSavedFile.write(b,nStart,nLen); {0YAzZ7
n = nLen; N{d@^Yj
} 6*@yE
catch(IOException e) Vga-@
{ 2yo cu!4l
e.printStackTrace (); fMf&?`V
} O''y>N9
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T{vR,
return n; eXl=i-'
} La[K!u\B
UF__O.l__
qO`qJ/
} C0x"pO7
/OGA$eP
9x`4RE
/* iz"3\{aN
**SiteInfoBean.java (!?K7<Jv
*/ )yxT+g2!
package NetFox; H'J|U|
%1:chvS
'q%%m/,VPQ
public class SiteInfoBean { Ps R>V)L
mE#nU(+Ta
s* jfMY
private String sSiteURL; //Site's URL ]qw0V
private String sFilePath; //Saved File's Path bZipm(e
private String sFileName; //Saved File's Name ")lw9t`
private int nSplitter; //Count of Splited Downloading File .+K S`
B>TSdn={>
D!TZI
public SiteInfoBean() l*7?Y7FK
{//nSplitter的缺省值为5 +'03>!V
//default value of nSplitter is 5 %3Bpn=k>
this("","","",5); vi {uy
} CV.+P-
_`a&9i &
.gYt0raSY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '5H4z7)
{ 3 EYiQ`
sSiteURL= sURL; yqSY9EX7
sFilePath = sPath; "2Op[~V
sFileName = sName; p/]s)uYp$
this.nSplitter = nSpiltter; %(LvE}[RJ
Ygkv7>?,
o7xgRSz\
} b7h+?!H]R
P -Fg^tl
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public String getSSiteURL() qSiWnN8D t
{ H}b\`N[nr
return sSiteURL; -fIc4u[
} w}<^l
NW.XA! =E)
CB*/ =Y
public void setSSiteURL(String value) hG Apuy
{ M$&>5n7
sSiteURL = value; #s+X+fe
} E8-53"m
YL5>V$i
y@apJ;_R-
public String getSFilePath() R,Ml&4pZ}
{ if~rp-\P
return sFilePath; XT||M)#
} j Selop>N
L0&S0HG
^,7=X8Su
public void setSFilePath(String value) *_)E6Y?9
{ i7eI=f-Q
sFilePath = value; W(&6
} 9qH[o?]
3ps,uozj
C{Blqf3V0
public String getSFileName() [b`6v`x
{ ')nnWlK
return sFileName; (K!4Kp^m
} SFO&=P:U
D<nxr~pQ
!A[S6-18%-
public void setSFileName(String value) .C5@QKU
{ T"W9YpZ
sFileName = value; %ejeyc
} 3Xdn62[&
R [9w
exphe+b
public int getNSplitter() Kpg:yrc['
{ oBw}hH,hp
return nSplitter; n>llSK
} +"L$ed(=nJ
"=A|K~b
B| Q6!
public void setNSplitter(int nCount) rl|Q)A{
{ ~t9Mh^gij
nSplitter = nCount; t:9 ZCu ay
} },6*Y*?{
} J~dTVBx
o>!JrH
*g$agyOfh
/* &s-VSu7
**Utility.java [.U^Wrd
*/ 6_ ]8\n
package NetFox; ^/{4'\p
aQh?}=da
l;5`0N?QO
public class Utility { }jcIDiSu
(C~dkR?
(rMZ
public Utility() 2f`xHI/@fj
{ >a9l>9fyY
ITn;m
[|<EDR
} yiO31uQt
qvTKfIl{
//线程睡眠 %Qd3BZ
public static void sleep(int nSecond) ZeTL$E[E}
{ FF@`+T
try{ (j=DD6fC
Thread.sleep(nSecond); hfh.eL
} x3;jWg~'
catch(Exception e) s7|3zqi
{ R2Yl)2 D
e.printStackTrace (); ni0LQuBp
} "GLYyC
} \^m.dIPdO
LJ l1v
//日志 =~$U^IsWA
public static void log(String sMsg) /h-6CR Ka
{ tGqQJT#mr7
System.err.println(sMsg); 54wM8'+
} .xnQd^qoac
Q;@X2JSp
\6LcVik
public static void log(int sMsg) {9'hOi50
{ O,]_ tp
System.err.println(sMsg); :H3(w|T/
} .m!s". ?[
} sZEgsrJh
gDj_KKd
&@"w-M
/* 1:YAn
**TestMethod.java NlMQHma
*/ ,W8au"
package NetFox; :@WLGK*u.
*G9 [j$
F_ _H(}d
public class TestMethod { Es~DHX
aulaX/'-_
excrXx
public TestMethod() F*X%N_n
{ ///xx/weblogic60b2_win.exe w. vY(s
try{ ,0FwBK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9Yd-m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UXQb={
SiteFileFetch fileFetch = new SiteFileFetch(bean); { $X X
fileFetch.start(); Jtpa@!M
} \ bC}&Iz6
catch(Exception e){e.printStackTrace ();} Kj=;>u
8`DO[Z
pB[%:w/@l:
} .oEFX8
EuLXtq
CR.bMF}
public static void main(String[] args) `M,Nd'5&|
{ xV?*!m$V%R
new TestMethod(); z6Fun
} ]|;7R^o3|
} u8xk]:%
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