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)); Aep](je
} T@P~A)>yo
for(int i=0;i<nEndPos.length-1;i++) WwWOic2
{ HRbv%
nEndPos = nStartPos[i+1]; wX6-WQR
} <wFmfrx+v
nEndPos[nEndPos.length-1] = nFileLength; XA>uCJf
} H$^9#{
} tQT<1Q02i
ZRw^< +
$>_`.*I/
//启动子线程 dD39?K/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yk4py0xVl
for(int i=0;i<nStartPos.length;i++) $39TP@?:Z)
{ .L1[Rv3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0(u}z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @C[p?ak
nStartPos,nEndPos,i); FxK!h.C.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +.^pAz U}R
fileSplitterFetch.start(); N:pP@o
} 9+<A7PM1T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VE/m|3%t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L">jSZW[[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =2rdbq6R
nEndPos = " + nFileLength); ]xb2W~
// fileSplitterFetch[nPos.length-1].start(); ume70ap}m
.)%,R
O#J7GbrHO
//等待子线程结束 x@O)QaBN!
//int count = 0; RHvKWt
//是否结束while循环 v&9:Wd*Iz'
boolean breakWhile = false; Mkt_pr
L:@COy
Dh#5-Kf%
while(!bStop) wpQp1){%Q
{ n) HV:8j~
write_nPos(); @_c&lToj_
Utility.sleep(500); As^eL/m2L
breakWhile = true; cR55,DR,#W
oL>o*/
gth_Sz5!#
for(int i=0;i<nStartPos.length;i++) Q=[ IO,f
{ Abmi=]\bx
if(!fileSplitterFetch.bDownOver) U_Mag(^-
{ :]8A;`G}
breakWhile = false; } 21!b :a
break; vs$.i
} #-"C_~-MH
} ?TW?2+
if(breakWhile) {m,LpI0wG
break; ?wIEXKI
td$RDtW[3
0d~?|Nv -
//count++; [;D1O;c'W.
//if(count>4) ] ONmWo77o
// siteStop(); y6G6wk;
} mL;oR4{
G$/Qcr6W<
PuBE=9,
System.err.println("文件下载结束！"); p>T
} Lke!VS!P&
catch(Exception e){e.printStackTrace ();} \qG` ts
} pOl6x iMx
rJ6N'vw>
A&-2f]L tl
//获得文件长度 wIF'|"
public long getFileSize() ?AI`,*^
{ sVnpO$
int nFileLength = -1; /;}o0 DYeW
try{ v.,D,6qZ
URL url = new URL(siteInfoBean.getSSiteURL()); 2G:KaQ)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cvtn,Ml6
httpConnection.setRequestProperty("User-Agent","NetFox"); oHV!>K_D
00Ye ]j_
[8WG
int responseCode=httpConnection.getResponseCode(); \K Kt&bKL
if(responseCode>=400) 4a.8n!sys
{ J/Ch /Sa
processErrorCode(responseCode); ~qA\u5sB9@
return -2; //-2 represent access is error HMKogGTTo
} criNeKa
4C;"4''L
,x[~|J!
String sHeader; $JK,9G[Vu
ZNDjk
T{'oR .g,
for(int i=1;;i++) IG:CWPU
{ |Ur$H!oe?'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r|953e
//Utility.log(in.readLine()); {Sc*AE&Y
sHeader=httpConnection.getHeaderFieldKey(i); _znn`_N:v
if(sHeader!=null) B/JMH 1r
{ )Tn(!.
if(sHeader.equals("Content-Length")) [bBPs&7u
{ +xYg<AFS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `]/0&S
break; 5~i}!n
} ^|cax|>
} Gs*X> D
else e~6>8YO+7j
break; 5J6~]J
} S=`#X,Wo
} U\"FYTC
catch(IOException e){e.printStackTrace ();} reNUIDt/c
catch(Exception e){e.printStackTrace ();} (~#-J7
Yjx4H
_U~~[I
Utility.log(nFileLength); !qs3fe<uh"
H5A7EZq}`
c 1{nOx
return nFileLength; u$(XZ;Jg
} i6:O9Km
W3B:)<f
wJWofFz
//保存下载信息（文件指针位置） $ 3.Y2&$T
private void write_nPos() s`dUie}y<
{ 7<93n`byM
try{ XK@Ct eP"
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^ `[T0X
output.writeInt(nStartPos.length); uNvdlY]
for(int i=0;i<nStartPos.length;i++) %?O$xQ.<
{ ~HUO$*U4<
// output.writeLong(nPos); D+4$l+\u
output.writeLong(fileSplitterFetch.nStartPos); mfgUf
output.writeLong(fileSplitterFetch.nEndPos); F<2qwP
} +!-U+W
output.close(); j<d,7
} p3cb_
catch(IOException e){e.printStackTrace ();} %$+bO/f
catch(Exception e){e.printStackTrace ();} @`rC2-V
} *#o2b-[V
zIc_'Z,b
C ?aa)H
//读取保存的下载信息（文件指针位置） rCdTn+O2
private void read_nPos() Oa'T$'
{ )JA^FQ5N
try{ PED5>90
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |h2=9\:]
int nCount = input.readInt(); E*#5OT
nStartPos = new long[nCount]; i [2bz+Z?
nEndPos = new long[nCount]; n wO5<b;
for(int i=0;i<nStartPos.length;i++) ^-qz!ib
{ R"O,2+@<.
nStartPos = input.readLong(); nMH:7[x3
nEndPos = input.readLong(); VJ-To}
} 6=jL2cqx
input.close(); wl%I(Cw{]
} ~4`3p=$
catch(IOException e){e.printStackTrace ();} U{8x.CJ]
catch(Exception e){e.printStackTrace ();} %ERR^
} 0 TOw4pC
md/NMC \
I\$?'q>
private void processErrorCode(int nErrorCode) l#3jJn
{ O+ J0X*&x
System.err.println("Error Code : " + nErrorCode); *30T$_PiX|
} fOz.kK[]
\_t[\&.a}
j.SE'a_
//停止文件下载 d+&w7/F
public void siteStop() !~ZAm3GwL
{ u~1 ,88&U
bStop = true; |:LklpdYe
for(int i=0;i<nStartPos.length;i++) -}"nb-RR\
fileSplitterFetch.splitterStop(); RtF!(gd
Lv:;}
\kC'y9k
} NsL!AAN[V
} -n6e;p]
//负责部分文件的抓取 (kSb74*g
**FileSplitterFetch.java Z>ztFU
*/ FdS'0#$
package NetFox; )Xice=x9
$!\Z_:
E[Ao*
import java.io.*; uUh6/=y
import java.net.*; hF9y^Hx4
D1Q]Z63,
fY 10a_@x
public class FileSplitterFetch extends Thread { H.)J?3
{R7m qzt
GCp90
String sURL; //File URL `6pz9j]
long nStartPos; //File Snippet Start Position LN=#&7=$c
long nEndPos; //File Snippet End Position !1`f84d
int nThreadID; //Thread's ID (O'O#AD
boolean bDownOver = false; //Downing is over 8hZc#b;
boolean bStop = false; //Stop identical mJME1#j$/|
FileAccessI fileAccessI = null; //File Access interface kf_*=ER
hGo/Ve+@
ro18%'RRI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException P$"s*otr
{ 3SI%>CO}
this.sURL = sURL; __)"-\w-_(
this.nStartPos = nStart; VaTA|=[;
this.nEndPos = nEnd; ?)e6:T(
nThreadID = id; `6{4?v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +@anYtv%7
} 4&H&zST//m
%TzdpQp"
fP{IW`t}]
public void run() {hx=6"@
{ 3OJGBiDAr
while(nStartPos < nEndPos && !bStop) &}VVr
{ &[$t%:`
W(PNw2
D1cnf"y^
try{ uEyus96 +
URL url = new URL(sURL); 8!7`F.BX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +e&Q<q!,q
httpConnection.setRequestProperty("User-Agent","NetFox"); sh}eKwh
String sProperty = "bytes="+nStartPos+"-"; 4J$dG l#f
httpConnection.setRequestProperty("RANGE",sProperty); NeniQeR
Utility.log(sProperty); {$v>3FG
7:wf!\@I
!$fF3^8-
InputStream input = httpConnection.getInputStream(); nT@FSt
//logResponseHead(httpConnection); l!%V&HJV
w,zm!
# 0/,teJk
byte[] b = new byte[1024]; LO)p2[5#R
int nRead; @|@6pXR.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) je=XZ's,i~
{ iG=XRctgj)
nStartPos += fileAccessI.write(b,0,nRead); IUQYoKz4}A
//if(nThreadID == 1) ?# )\SQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G_6!w//
} &u~%5;
nLnzl
UsdUMt!u
Utility.log("Thread " + nThreadID + " is over!"); Tywrh9[
bDownOver = true; -FQS5Zb.!
//nPos = fileAccessI.write (b,0,nRead); JO\KTWtjO
} {e83 A/{
catch(Exception e){e.printStackTrace ();} >;k~B
} _ Zzne
} Q=#!wWVP
':|?M B
D~@lpcI
//打印回应的头信息 $ZnVs@:S
public void logResponseHead(HttpURLConnection con) &F|Wk,y
{ YG>6;g)Zm
for(int i=1;;i++) \$2zF8
{ N1X;&qZDd
String header=con.getHeaderFieldKey(i); ;`FR1KIg
if(header!=null) nLBi}T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $TavvO%#
Utility.log(header+" : "+con.getHeaderField(header)); ~{!,ZnO*
else 0ZtH
break; *5R91@xt
} "oT]_WHqo
} ]H=P(Z-
I7jIA>ZZi
A]m_&A#
public void splitterStop() 2w/qH4
{ Q&?B^[N*Q
bStop = true; #oEq)Vq>g|
} "nC=.5/$
qgsw8O&
>I9|N}I
} UQCond+K
7kQ,D,c'
5 OF*PBZ
/* hVu~[ 'Me
**FileAccess.java Y~I6ee,\
*//文件访问(定位，写) scR+F'M
package NetFox; %)j^>W5
import java.io.*; =N{-lyr)
1xMD )V:
60%EmX ;
public class FileAccessI implements Serializable{ ,\E5et4
,4kipJ!,yK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K<7 Db4H
RandomAccessFile oSavedFile; RUlJP
long nPos; 8^"P'XQ
{m5R=22^
> V%3w7
public FileAccessI() throws IOException *Y- rEF>
{ T eBJ
this("",0); He)dm5#fg
} }}~ t!/x
Pna2IB+
C~:!WRCz
public FileAccessI(String sName,long nPos) throws IOException ?&r>`H E
{ Op:7EdT#
oSavedFile = new RandomAccessFile(sName,"rw"); bL18G(5
this.nPos = nPos; -xc'P,`
oSavedFile.seek(nPos); X.<2]V7!
} h*?/[XY
/A/k13 J
>rzpYc'~w
public synchronized int write(byte[] b,int nStart,int nLen) %#b+ =J
{ WJ(E3bb
int n = -1; ?3Dsz
try{ Ue]GHJ2
oSavedFile.write(b,nStart,nLen); 3?oj46gP
n = nLen; H1g"09?h6o
} B=J/HiwV)
catch(IOException e) {"w4+m~+te
{ J0"<}"
e.printStackTrace (); pM'AhzS
} 'Z(4Wuwb
gEQevy`T%c
$2\k| @)s
return n; _Vxk4KjP5
} ~",,&>#[K
[sH[bmLR
Qr l>A*
} iv62Fs'
SgocHpyg
K# dV.
/* (J^2|9r
**SiteInfoBean.java ^atBf![
*/ S\O6B1<:
package NetFox; ^~%zPlv
p%6j2;D
y-c2tF@'v
public class SiteInfoBean { >O&:[CgEF
BnLWC
ij=}3;L_!
private String sSiteURL; //Site's URL /N&)r wc
private String sFilePath; //Saved File's Path bqDHLoB\1
private String sFileName; //Saved File's Name #7A_p8
private int nSplitter; //Count of Splited Downloading File :h+gSvn:
q"[8u ]j
7!E?(3$#"
public SiteInfoBean() 2!35Tj"RFE
{//nSplitter的缺省值为5 =pP0dvn
//default value of nSplitter is 5 6M`N| %
this("","","",5); HjAQF?;V
} Jh'\ nDz@e
\VX~'pkrd/
NN9`jP2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) eY1$smh t
{ Bld$<uU
sSiteURL= sURL; ?>W4*8(
sFilePath = sPath; Z)zWfv}
sFileName = sName; hd2 X/"
this.nSplitter = nSpiltter; 2I#4jy/g
u9*}@{,
+89s+4Jn
} N@>,gm@UU
-/.Xf<y58
VzR(OB
public String getSSiteURL() 6"Km E}
{ Jn>7MuG
return sSiteURL; GP5Y5)
} xPY/J#X$
I"]5B
@JWoF^U
public void setSSiteURL(String value) zOpl#%"
{ (c<Krc h
sSiteURL = value; uLsGb=m%b
} D@i,dPz5Zl
Ne<"o]_M
$Wy7z^t
public String getSFilePath() Eg"DiI)7
{ $Gs&' yR
return sFilePath; \vB-0w
} }*~EA=YN;
oVsj Q
p1Q[c0NMK
public void setSFilePath(String value) \*H/YByTb
{ dUtxG ~9
sFilePath = value; {6v|d{V+e
} 2roPZj
z^Nnt
${#5$U+kI
public String getSFileName() @^y/V@lDm
{ ~pn9x;N%H
return sFileName; "-y\F}TE
} 2,O-/A;tW*
UAT46
"aN<3b
public void setSFileName(String value) oh`I$
{ CJ_X:Frj)
sFileName = value; :<=!v5 SK
} QeA)@x.p
/>XfK,c-
cI4%zeR
public int getNSplitter() L`YnrDZK
{ y6'Fi(2yw
return nSplitter; hA?j"y0?
} 5+GW%U/
ics
Phl't~k
public void setNSplitter(int nCount) :tM|$TZ
{ j3VM!/
nSplitter = nCount; R:B-4
} 9Ps:]Kp!vN
} %4cUa| =?
5oplV(<?*S
A6}M F
/* ]Ole#Lz}Q
**Utility.java \~Zj](#
*/ .G1NY1\
package NetFox; KO<fN,DR
(o{-1Dg)
'g#Ml`cm
public class Utility { Kwfrh?
E8=.TM]L
F&;g< SD
public Utility() h$~ NPX
{ \P!v9LX(
b,7:=-D
<(?ahO5
} >DQl&:-)t
N2;T\xx,
//线程睡眠 6-gxba
public static void sleep(int nSecond) JJ,Fh .
{ \,[Qg#W$u
try{ AZorzQ]s
Thread.sleep(nSecond); (iGk]Rtzt
} W+a>*#*
catch(Exception e) 5wRDH1z@{
{ s>~!r.GC
e.printStackTrace (); y ']>J+b0
} zrU0YHmt
} dI-=0v-|
.Q?cNSWU
//日志 }0?642 =-
public static void log(String sMsg) ]ss0~2
{ _+wou(1y
System.err.println(sMsg); %S$`cp
} ,y,NVF
]0xbvJ8oK
B!!xu
public static void log(int sMsg) #It{B
{ c%Yvj
System.err.println(sMsg); #; E,>0
} DuZ51[3_L
} +=|Q'V
nBaY|
B~lrd#qC
/* Q)C#)|S
**TestMethod.java Sq UoXNw
*/ 8Y sn8
package NetFox; d'kQE_y2.
{_ww1'|A
k:Uyez
public class TestMethod { w%VHq z$
2hw3+o6
_z)G!_7.>\
public TestMethod() 1*[h$Z&H?
{ ///xx/weblogic60b2_win.exe ^;<s"TJ(m)
try{ _|wgw^.LJ]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -mO[;lO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TWQf2
SiteFileFetch fileFetch = new SiteFileFetch(bean); "\vEi &C
fileFetch.start(); .O3i"X]
} W.-[ceM
catch(Exception e){e.printStackTrace ();} E6NkuBQ((
`w@fxv
6*S|$lo9B
} 4M6o+WV
C=h$8Q
1V+a;-?
public static void main(String[] args) <3LyNG.
{ 'vhgR2/
new TestMethod(); sn+i[
} Aw;~b&.U{_
} rfkk3oy
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