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)); *+E9@r=HF
} D\:~G}M
for(int i=0;i<nEndPos.length-1;i++) sf|[oD
{ TV>UD q
nEndPos = nStartPos[i+1]; 8^H <dR
} *(~=L%s
nEndPos[nEndPos.length-1] = nFileLength; uQ;b'6Jcp
} <3!jra,h
} A3UC=z<y
iG[an*#X
JvHGu&Nr!
//启动子线程 y`~[R7E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ((U-JeFW
for(int i=0;i<nStartPos.length;i++) S> f8j?n
{ sQT0y(FW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T1@]:`&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Hm?zMyO.k
nStartPos,nEndPos,i); j HOE%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T/^ /U6JB
fileSplitterFetch.start(); #_tixg
} 2<aBUGA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pvJsSX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); nKFua l3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m|O7@N
nEndPos = " + nFileLength); 6 ]@H.8+
// fileSplitterFetch[nPos.length-1].start(); .[-d( #l{l
C^po*(W6
?PIOuN=
//等待子线程结束 K"cN`Kj<*-
//int count = 0; <B;l).[6
//是否结束while循环 r )cGee
boolean breakWhile = false; e1dT~l
5o~;0K]
Ksq{=q-T
while(!bStop) dpO ZqhRs.
{ T(<C8
write_nPos(); G<C[A
Utility.sleep(500); <Gy)|qpK[
breakWhile = true; +oY[uF
'm@0[i
9HlRf6S
for(int i=0;i<nStartPos.length;i++) r^?Qo
{ ZJ} V>Bu-
if(!fileSplitterFetch.bDownOver) hsVf/%
{ pJ6Z/3]
breakWhile = false; Qwn/ ,
break; 7_WD)Y2yS
} v1yNVs\}
} IYq)p /
if(breakWhile) 'IweN
break; (u81p
Tp.0@aC
r00 fvZyK
//count++; S x';Cj-
//if(count>4) "-Lbz)k
// siteStop(); W9~vBU
} !3{> F"
C>q,c3s5
V:rq}F}
System.err.println("文件下载结束！"); **V^8'W<
} ">}l8MA
catch(Exception e){e.printStackTrace ();} I| qoHN,g
} dnVl;L8L3
@,D 3$P8}
)W!8,e+%
//获得文件长度 8[SiIuIV
public long getFileSize() [kx_Izi/T
{ 2T &<jt
int nFileLength = -1; `}ak;^Me
try{ $srb!&~_>
URL url = new URL(siteInfoBean.getSSiteURL()); LB_ylfg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k&4@$;Ap
httpConnection.setRequestProperty("User-Agent","NetFox"); 3jIi$X06
=dD<[Iz6
?b0VB
int responseCode=httpConnection.getResponseCode(); MR/jM@8
if(responseCode>=400) (MiEXU~v
{ j?ihUNY!+
processErrorCode(responseCode); -b"7WBl
return -2; //-2 represent access is error yjODa90!G
} 7@u0;5p|
=(ts~^
OPR+K ?
String sHeader; C`c;I7
r>1M&Y=<
[?mDTD8zU
for(int i=1;;i++) Y,OSQBgk
{ P g.PD,&U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6LRI~*F=3
//Utility.log(in.readLine()); m!3L/UZ
sHeader=httpConnection.getHeaderFieldKey(i); V3fd]rIP
if(sHeader!=null) EOu\7;kE9
{ 6CBk,2DswI
if(sHeader.equals("Content-Length")) L;=:OX0
{ & IVwm"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $Scb8<
break; 7u]0dHj
} ]q DhGt
} aJlSIw*Q,
else Be+CV">2
break; $E@L{5Yt
} |'WaBy1
} +U9Gj#
catch(IOException e){e.printStackTrace ();} DTrS9j?z
catch(Exception e){e.printStackTrace ();} n*G[ZW*Uc
S?Q4u!FC
S+>1yvr),
Utility.log(nFileLength); Bi9b"*LN
w*`5b!+/
|?6r&bT
return nFileLength; il `O*6-
} XQ&iV7
%pmowo~{
5inmFT?9Z
//保存下载信息（文件指针位置） Q.Hy"~
private void write_nPos() nYG$V)iCb
{ dg/OjiD[P
try{ 0lR/6CB
output = new DataOutputStream(new FileOutputStream(tmpFile)); !>T.*8
output.writeInt(nStartPos.length); fyIL/7hzf4
for(int i=0;i<nStartPos.length;i++) Xxcv5.ug
{ 3+_? /}<
// output.writeLong(nPos); }R:e[lKj
output.writeLong(fileSplitterFetch.nStartPos); ^& ZlV
output.writeLong(fileSplitterFetch.nEndPos); ab8uY.j
} *[jG^w0z8~
output.close(); ]Ln2|$R
} z"8%W?o>
catch(IOException e){e.printStackTrace ();} WmTSxneo
catch(Exception e){e.printStackTrace ();} rD)yEuYX
} Dk4Jg++
+HNY!fv9
XYIZ^_My
//读取保存的下载信息（文件指针位置） [8AGW7_
private void read_nPos() sJ)XoK syW
{ ''S*B|:
try{ 4`5jq)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Jr m<ut
int nCount = input.readInt(); AVyO5>w
nStartPos = new long[nCount]; v;"[1w}
nEndPos = new long[nCount]; vt}+d StUm
for(int i=0;i<nStartPos.length;i++) 8qL*Nf
{ Xk%92Pto
nStartPos = input.readLong(); g#qt<d}j
nEndPos = input.readLong(); #?.Yc%5B
} yS0YWqv]6@
input.close(); @O9.~6
} N*w/\|
catch(IOException e){e.printStackTrace ();} kFmd):U!R
catch(Exception e){e.printStackTrace ();} %7 h_D
} <CIJg*
s@sRdoTdF
DK 4 8
private void processErrorCode(int nErrorCode) h}fz`ti U
{ _2+}_ >d
System.err.println("Error Code : " + nErrorCode); & .VciSq6
} o5KpiibFM
XL>v$7`#
x'_I{$C&
//停止文件下载 %[0V>
public void siteStop() |SC^H56+
{ VE5w!of
bStop = true; KCd}N
for(int i=0;i<nStartPos.length;i++) [YG\a5QK
fileSplitterFetch.splitterStop(); @ SaU2
s7=CH
V8ka*VJ(B
} B9pro%R1Bo
} j+AAhn
//负责部分文件的抓取 n;8[WR)
**FileSplitterFetch.java U<J4\|1?7'
*/ fCTdM+t
package NetFox; (&R/ns~
HbQ `b
'PRsZ`x.
import java.io.*; R=P=?U.
import java.net.*; Y`jvza%
$j*%}x~[
%Cbqi.iuQ
public class FileSplitterFetch extends Thread { |k$^RU<OF
FWI<_KZO
]s-;*o\H
String sURL; //File URL x? 3U3\W
long nStartPos; //File Snippet Start Position W1S7%6y_1
long nEndPos; //File Snippet End Position 8P5yaS_
int nThreadID; //Thread's ID Rhh5r0 \5
boolean bDownOver = false; //Downing is over ||3%REliC
boolean bStop = false; //Stop identical !'uL
FileAccessI fileAccessI = null; //File Access interface V(Ll]g/T_;
PjZsMHW%
Ag=>F5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZaJg$
{ mne4uW
this.sURL = sURL; - y[nMEE
this.nStartPos = nStart; (c;F%m|
this.nEndPos = nEnd; -Yx'qz@
nThreadID = id; y<(q<V#0!S
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !gA<9h
} *YmR7g|k
sFv68Ag+
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public void run() nNJU@<|{*
{ ?g gl8bzA
while(nStartPos < nEndPos && !bStop) GlkTpX^b
{ NrH2U Jm
FJo?~
8qGK"%{ ~
try{ ("-Co,4ey
URL url = new URL(sURL); ApHs`0=(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [4L[.N@
httpConnection.setRequestProperty("User-Agent","NetFox"); #DK@&Gv
String sProperty = "bytes="+nStartPos+"-"; ^\=<geEj
httpConnection.setRequestProperty("RANGE",sProperty); "8}p>gS
Utility.log(sProperty); As0E'n85
D^ZG-WR
;hb;%<xqT
InputStream input = httpConnection.getInputStream(); e;L++D
//logResponseHead(httpConnection); h>\T1PM
\d$fi*{
.l?sYe64S
byte[] b = new byte[1024]; C+ar]Vi
int nRead; " &2Kvsz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "D#+:ix8G|
{ 91%QO?hz
nStartPos += fileAccessI.write(b,0,nRead); BSt^QH-'
//if(nThreadID == 1) }jHS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~I[Z2&I
} "TW%-67
y#F`yXUj
GaV6h|6_
Utility.log("Thread " + nThreadID + " is over!"); Q@]~O-
bDownOver = true; _8x:%$
//nPos = fileAccessI.write (b,0,nRead); u^.7zL+
} | 4/'~cYV
catch(Exception e){e.printStackTrace ();} `{w.OK
} 52Sq;X
} N$>.V7H&
$yxwB/O(
d%+oCoeb
//打印回应的头信息 ,z<J`n
public void logResponseHead(HttpURLConnection con) ipzv]c&
{ \Ps}1)wT
for(int i=1;;i++) cV]c/*zA
{ J>_|hg=
String header=con.getHeaderFieldKey(i); {wsO8LX
if(header!=null) )CgKZ"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @BQJKPF*
Utility.log(header+" : "+con.getHeaderField(header)); x\(@v
else "#zSk=52z
break; y!_*CYZ~m
} S,ZlS<Z#
} e4:,W+g,9
s Dq{h
7{jB!Xj
public void splitterStop() 2to~=/.
{ |2RoDW
bStop = true; ~,#zdm1r@
} l0Rjq*5hJ
RcJ.=?I!
a)L\+$@*
} 581Jp'cje
TA;r
."`mh&+`
/* >]b>gc?3
**FileAccess.java akR+QZ,)
*//文件访问(定位，写) ])`+ 78
package NetFox; x=-dv8N?
import java.io.*; =NJ:%kvF
#63)I9>
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public class FileAccessI implements Serializable{ 5e)2Jt:
;B Lw?kf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GSlvT:k
RandomAccessFile oSavedFile; [=3f:>ssm
long nPos; /hrVnki*
*[XVkt`H
_#f+@)vR
public FileAccessI() throws IOException `)i'1E[9
{ 2=R}u-@6p
this("",0); W=QT-4
} S ^5EG;[
Ug}dw a
Sr$&]R]^
public FileAccessI(String sName,long nPos) throws IOException D,$!.5OA
{ j%w}hGW%,
oSavedFile = new RandomAccessFile(sName,"rw"); 6?B'3~r
this.nPos = nPos; K;uOtbdOK
oSavedFile.seek(nPos); R0yPmh,{
} cXcrb4IKD
pTzwyj!SD
+=_^4
public synchronized int write(byte[] b,int nStart,int nLen) TNi4H:\
{ SynL%Y9)|,
int n = -1; w_gFN%8
try{ +-%&,>R
oSavedFile.write(b,nStart,nLen); VIIBw
n = nLen; YgiLfz iT
} u/s,#
catch(IOException e) "6^~-`O
{ (w1M\yodV
e.printStackTrace (); .~3s~y*s
} ,Z3 (`ftC
B7'rbc'
>JSk/]"
return n; NY(z3G
} 5Q/&,NP
!UzMuGj
8%+F.r
} Wi;wu*
)Bz2-|\
/5**2Kgv1
/* J&hzr t
**SiteInfoBean.java a9f!f %9
*/ AiF'*!1
package NetFox; w(,K
'R-Ly^:Qd
UrC>n
public class SiteInfoBean { N}|<P[LW
g$^:2MT"aQ
NA :_yA"
private String sSiteURL; //Site's URL E*B6k!:
private String sFilePath; //Saved File's Path H$@5\pP>
private String sFileName; //Saved File's Name {fd/:B 7T
private int nSplitter; //Count of Splited Downloading File 9~rrN60Q
;nSOeAF)Q
. X:
public SiteInfoBean() \Fh#CI
{//nSplitter的缺省值为5 bmid;X|
//default value of nSplitter is 5 fen~k#|l
this("","","",5); AhyV
} UnE[FYx
},]G +L;R
$.5f-vQp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c4Leh"ry
{ ~[N"Q|D3Y
sSiteURL= sURL; B2kKEMdGg
sFilePath = sPath; 1WP(=7$.
sFileName = sName; ~dtS
this.nSplitter = nSpiltter; n)<S5P?
;h"St0
B=<Z@u
} hf`5NcnP
VG=mA4Dd
5LX'fL7zU
public String getSSiteURL() ~K2.T7=
{ TXWYQ~]3w
return sSiteURL; mVs<XnA47
} lSG"c+iV
\jpm
_\ &N<
public void setSSiteURL(String value) .%"s| D
{ 5R%4fzr&g
sSiteURL = value; A &tMj?
} G u4mP
nOQvBc
m>:zwz< ;
public String getSFilePath() SDbR(oV
{ Ovhd%qV;Y
return sFilePath; ]ZI ?U<0
} ^o8o
e[($rsx
AE@N:a
public void setSFilePath(String value) ll^#I/
{ 6rll0c~
sFilePath = value; />dH\KvN
} u}0U!
H[DBL
vU9j|z
public String getSFileName() MXP3ZN'
{ + FG Xx
return sFileName; K;'s+ZD
} *dpKo&y
xm*6I
<tn6=IV
public void setSFileName(String value) n7p,{KSQ
{ xgQ&'&7l
sFileName = value; uLq%Nu
} S2\|bs7;J,
&_o.:SL|
cYx.<b JH
public int getNSplitter() @s%!R
{ Q1 5h \!u
return nSplitter; it)!-[:bm
} )KbzgmLr
Q~-MB]'
RQ*oTsq
public void setNSplitter(int nCount) w7e+~8|
{ *%aWGAu:
nSplitter = nCount; Z[GeU>?P
} 5<77o|
} &<Iz?AVr
*Z}9S9YtN
gNaB^IY
/* 8r\;8all
**Utility.java Y7GHIzX
*/ @\?QZX(H
package NetFox; "~,3gNTzV
2S@aG%-)
gw_]Y^U
public class Utility { I=c}6
!)//b]
g&?RQ
public Utility() "V>p
{ J5#shs[M:
"eH.<&
P>wTp)
} *V[6ta'
*R_mvJlT
//线程睡眠 5`A^"}0
public static void sleep(int nSecond) 5-B %08T
{ 48g`i
try{ ;0JK>c ]#
Thread.sleep(nSecond); e"^n^_9
} `&/~%>
catch(Exception e) Z9p`78kYyh
{ *Hed^[sO
e.printStackTrace (); ( SiwO.TZ
} X775j"<d
} i"GCm`
9*CJWS;
//日志 p;P cD
public static void log(String sMsg) BW{&A&j
{ Uy;e5<<
System.err.println(sMsg); +2Wijrn
} H^JwaF
-;RW)n^n
z$b'y;k
public static void log(int sMsg) )Q)H!yin
{ bSm*/Q
System.err.println(sMsg); Cp!Qd e
} 7 P/1'f3
} b3^d!#KVM
)D8V;g(7F
<wj}y0(
/* QQW]j;'~
**TestMethod.java oeF0t'%
*/ 1 R,?kUa
package NetFox; Y8@TY?
hNUkaP
0oNy
public class TestMethod { K['Gp>l
nmy!.0SQ-
dA[S@ysvG
public TestMethod() ]`T*}$|
{ ///xx/weblogic60b2_win.exe 5o2vj8::
try{ hw)#TEt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;pVnBi
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y:KIaYkk
SiteFileFetch fileFetch = new SiteFileFetch(bean); %C=?Xhnv
fileFetch.start(); /PTk296@
} .yN.
catch(Exception e){e.printStackTrace ();} Xb\de_8!
+xojnv
7Ug^aA
} dW} m44X
tJ9-8ZT*
x>eV$UJ
public static void main(String[] args) +GFK!Pf
{ ^M7pCetjdW
new TestMethod(); Q'R*a(pm
} K/IG6s;Xj
} zPW_
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