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)); 6H:EBj54?
} {=_xze)
for(int i=0;i<nEndPos.length-1;i++) Y4*?QBYA
{ *'R2Lo<C
nEndPos = nStartPos[i+1]; ? \NT'CG
} E9j(%kQ2
nEndPos[nEndPos.length-1] = nFileLength; j{P3o<l&`
} 0vM,2:kf*
} ;+Mr|vweTC
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e3kdIOu5
//启动子线程 IE&G7\>(yO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [q!)Y:|u_>
for(int i=0;i<nStartPos.length;i++) IF3V5Q
{ _x?S0R1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m\ /V0V\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \>4x7mF!
nStartPos,nEndPos,i); WI54xu1M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *JVJKqed
fileSplitterFetch.start(); :#UN^"(m}
} q|e<b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qFjnuQ,w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 92L{be;SY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8C2!Wwz`J8
nEndPos = " + nFileLength); VB{G%!}
// fileSplitterFetch[nPos.length-1].start(); Fr9_!f
=eG:Scoug?
el,n5OZ7
//等待子线程结束 6}PoBhgSg-
//int count = 0; )>a^%V9
//是否结束while循环 9wv 7HD|
boolean breakWhile = false; ; J8 25CE
/ee4 v!
r;8$ 7C.
while(!bStop) P87qUC
{ 6Q9S~YYq
write_nPos(); Q |^c5
Utility.sleep(500); b=Y3O
breakWhile = true; )nUTux0K\
Y--Uo|H
xsXf_gGu
for(int i=0;i<nStartPos.length;i++) )"<:Md$7
{ p\M\mK
if(!fileSplitterFetch.bDownOver) c(0Ez@
{ 1 *$-.
breakWhile = false; 5[$jrG\!
break; >]WQ1E[=
} 5K?%Eo72!=
} +)TOcxF%
if(breakWhile) yy|F6Pq3`
break; AN-;*n<'
@KC;"u'C
#[Vk#BIiv8
//count++; pJ]i)$M
//if(count>4) 3UQ~U 8
// siteStop(); Fv9n>%W&
} xGymQ|y84
9$P*fx&m
t~FOaSt
System.err.println("文件下载结束！"); Hf$LWPL)lM
} KmRxbf
catch(Exception e){e.printStackTrace ();} STgYXA(
} QsH Fk5)
JD$;6Jv3P
W=T,hOyh<W
//获得文件长度 QOY M/1U
public long getFileSize() 8&9'1X5)8_
{ ;yg9{"O
int nFileLength = -1; 2:& [r*
try{ UI.>BZ6}
URL url = new URL(siteInfoBean.getSSiteURL()); uSK<{UT~3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $WK~|+"{>
httpConnection.setRequestProperty("User-Agent","NetFox"); ~gvw6e*[
{F+iL&e)
n:[GK_
int responseCode=httpConnection.getResponseCode(); m;KD@E!
if(responseCode>=400) 8?&u5
{ .m\'|%
processErrorCode(responseCode); ^{Y9!R*9U*
return -2; //-2 represent access is error 0|_d{/VK4
} >R}p*=J
E`>u*D$un~
5A=FEg
String sHeader; ]QAMCu(>
9~$'?
Gfn?1Kt{
for(int i=1;;i++) ?_7^MP>
{ itW~2#nJz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); seo.1.Da2
//Utility.log(in.readLine()); }~`l!ApD
sHeader=httpConnection.getHeaderFieldKey(i); j-j,0!T~b
if(sHeader!=null) )YP9
{ "kT?9&
if(sHeader.equals("Content-Length")) wsLfp82
{ Ykd< }KE>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =HkB>w)h
break; x4vowF
} ..hD_k
} _lj&}>l
else :Pf2oQ
break; &*wc` U
} Da"GYEC
} +_LWN8F
catch(IOException e){e.printStackTrace ();} k3B-;%3I;
catch(Exception e){e.printStackTrace ();} ;J3 (EB
t!,GI&
c*#*8R9.y
Utility.log(nFileLength); @d86l.=
B`SHr"k!V[
coQ>CbHg
return nFileLength; bR}{xHe
} Iib39?D W
i5 F9*
R87e"m/C%
//保存下载信息（文件指针位置） B> LL *
private void write_nPos() Ho;bgva
{ |}>;wZ[7
try{ +Tw]u`
output = new DataOutputStream(new FileOutputStream(tmpFile)); J< U,~ra\
output.writeInt(nStartPos.length); !3'&_vmG$
for(int i=0;i<nStartPos.length;i++) @(mXiK
{ `<:D.9vO "
// output.writeLong(nPos); 5<y pK`Kq
output.writeLong(fileSplitterFetch.nStartPos); I6E!$}
output.writeLong(fileSplitterFetch.nEndPos); !DUC#)F
} Hs~u&c
output.close(); z;VabOr^
} g$jZpU
catch(IOException e){e.printStackTrace ();} E}WO?xxv74
catch(Exception e){e.printStackTrace ();} $m-rn'Q
} h!L6NS_Q,
zU)Ib<$
4D-4BxN*
//读取保存的下载信息（文件指针位置） }}'0r2S
private void read_nPos() nmZJ%n
{ y`OL^D4
try{ nwm1YPs%v]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (n,!v)
int nCount = input.readInt(); fudIUG.
nStartPos = new long[nCount]; o@&dd NO
nEndPos = new long[nCount]; l6lyRJ
for(int i=0;i<nStartPos.length;i++) 7FiQTS B:
{ Tp7slKc0p
nStartPos = input.readLong(); 41[1_p(
nEndPos = input.readLong(); xrPC
} qg+bh
input.close(); p7pJ90~E
} (wRJ"Nwu
catch(IOException e){e.printStackTrace ();} &gL &@';,
catch(Exception e){e.printStackTrace ();} 8T#tB,<fFW
} \%FEQa0u
,{br6*E
-}Iw!p#O3
private void processErrorCode(int nErrorCode) Uxyj\p
{ *=X$j~#X
System.err.println("Error Code : " + nErrorCode); i;XkH4E:)
} yfd$T}WW6
QIMoe'p
&~xzp^&
//停止文件下载 LT3ViCZ-n
public void siteStop() RN%*3{-
{ ,'m<YTF
bStop = true; *"pf3x6
for(int i=0;i<nStartPos.length;i++) #H@rb
fileSplitterFetch.splitterStop(); H?(I-vO
&7YTz3aj
W_E0+
} [0(+E2/:2
} a\Ond#1p
//负责部分文件的抓取 /b)V=mcR
**FileSplitterFetch.java $#/-+>
*/ |9F^"7Q~C
package NetFox; w<ol$2&B
/ ao|v
!Deg!f\g
import java.io.*; }op0`-Xb
import java.net.*; }? W[D
8a^E{x@HT
,/=Fm
public class FileSplitterFetch extends Thread { $dp;$X3
.ZB(!v/2
9f ^c9@=
String sURL; //File URL x dT1jI
long nStartPos; //File Snippet Start Position >2[\WF*"X
long nEndPos; //File Snippet End Position 1$*ZN4
int nThreadID; //Thread's ID "0(H! }D
boolean bDownOver = false; //Downing is over Vu/{Hr
boolean bStop = false; //Stop identical C#r1zr6
FileAccessI fileAccessI = null; //File Access interface Y|NANjEAfm
s 9Y'MQo*
/2!Wy6p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5VU 5kiCt
{ E8Jy!8/X9T
this.sURL = sURL; \C )S3!h
this.nStartPos = nStart; ?4kM5NtP
this.nEndPos = nEnd; t@`w}o[#
nThreadID = id; _i=431Z40
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7$l!f
} ._uXK[c7P
"lFS{7
^11y8[[
public void run() 6i6m*=h
{ 9Dq^x&z(
while(nStartPos < nEndPos && !bStop) u]W$'MyY
{ vCf{k
@MS}tZ5
SpM|b5c5
try{ xb2xl.2x!
URL url = new URL(sURL); KkIxtFM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g/o@,_
httpConnection.setRequestProperty("User-Agent","NetFox"); `FjU2 O
String sProperty = "bytes="+nStartPos+"-"; J 8z|ua
httpConnection.setRequestProperty("RANGE",sProperty); <]~FX25
Utility.log(sProperty); [f^:V:){
g9A8b(>F&@
6`tc]a"#Zb
InputStream input = httpConnection.getInputStream(); Rd?8LLz
//logResponseHead(httpConnection); ,:I:F
vqC!Ajm
U.fLuKt
byte[] b = new byte[1024]; 5 (Lw-_y#
int nRead; _</>`P[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *kmD/J
{ \i*QKV<
nStartPos += fileAccessI.write(b,0,nRead); H+ P&} 3
//if(nThreadID == 1) x:7"/H|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y+,ii$Ce~
} cN#c25S>
59Lv/Mfy
Dsl,(qm5
Utility.log("Thread " + nThreadID + " is over!"); 0^H"eQO
bDownOver = true; xnuu#@f
//nPos = fileAccessI.write (b,0,nRead); r~K5jL%z9
} ZU=omRh5
catch(Exception e){e.printStackTrace ();} xppl6v(
} BwLggo
} i#&iT P`
r%craf
I`$"6 Xy
//打印回应的头信息 FN$sST
public void logResponseHead(HttpURLConnection con) kM0TQX)$m
{ Bb,l.w
for(int i=1;;i++) 3Kx&+
{ =bx;TV
String header=con.getHeaderFieldKey(i); TpB4VNi/<
if(header!=null) 4"om;+\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I%^Bl:M
Utility.log(header+" : "+con.getHeaderField(header)); K1th>!JW'
else 6n|R<DO%\
break; BHNcE*U}@?
} eWN[EJI<
} GOKca%DT=
,2|(UTv
Oc Gg'R7
public void splitterStop() rZij[6]Y^
{ %`4\ 8H`
bStop = true; ;?{N=x8
} *%3%Zj,{
'ie+/O@G
?~%Go
} agbG)t0
aUGRFK_6$
TrYt(F{t
/* 0r=KY@D
**FileAccess.java 'lsG?
*//文件访问(定位，写) L[D<e?j
package NetFox; wWI1%#__|o
import java.io.*; kH.W17D~
Vr<eU>W
)YtdU(^J$
public class FileAccessI implements Serializable{ kBRy(?Mft&
j>}<FW-N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6h5,XcO4
RandomAccessFile oSavedFile; 0b)q,]l]
long nPos; 5DI&pR1eZ
<>Nq]WqA
?oD]J
public FileAccessI() throws IOException 5x2m]u
{ N!{waPbPi
this("",0); ,\DSi&T
} !,(6uO%
8mmHefZ}2!
J7RO*.O&Iq
public FileAccessI(String sName,long nPos) throws IOException ![ce=9@t<
{ [X\<C '<
oSavedFile = new RandomAccessFile(sName,"rw"); ~+~^c|
this.nPos = nPos; )B!64'|M
oSavedFile.seek(nPos); F?!X<N{
} gG,"wzj
ndXUR4
RT~6#Caf
public synchronized int write(byte[] b,int nStart,int nLen) MYlPG1X=?
{ 8fH.E
int n = -1; 2Hp<(
try{ A.v'ws+VDP
oSavedFile.write(b,nStart,nLen); Fv )H;1V
n = nLen; s"xiGp9
} #cAX9LV
catch(IOException e) evLZ<|
{ 0dKv%X#\
e.printStackTrace (); 7`G FtX}
} t0"2Si
ju8DmC5
x\R%hGt
return n; \Wn0,%x2
} $Lc-}m9n
}jI=*
rIhe}1
} H6vO}pq)r
6+iZJgwAy
gz~)v\5D/
/* &~ .n}h&
**SiteInfoBean.java &$x1^
*/ !D!1%@ e
package NetFox; ,WKWin
yQ/E0>Uj!
DOa%|H'P
public class SiteInfoBean { ukAE7O(W&
:W6R]y
KB\A<(o,
private String sSiteURL; //Site's URL v6#i>n~x,
private String sFilePath; //Saved File's Path qJyGr ?
private String sFileName; //Saved File's Name "?f_U/+D<
private int nSplitter; //Count of Splited Downloading File jg3X6/'
z7PmyU >
"Ei' FM
public SiteInfoBean() BM+>.
{//nSplitter的缺省值为5 {I9<W'k{
//default value of nSplitter is 5 i\yp(tE%^
this("","","",5); _KSlIgQ }0
} @@QB,VS;{<
ol#4AU`
zir?13N7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "P9SW?',
{ W02t6DW
sSiteURL= sURL; +DR,&;
sFilePath = sPath; ySP%i6!au
sFileName = sName; !hc#il'g].
this.nSplitter = nSpiltter; -SeHz.`N
ysDGF@wZC
62Q`&n6
} ~ ~U,
l2ww3)Z
Y2&hf6BE
public String getSSiteURL() } >zl
{ &f_ua)cyY
return sSiteURL; 6EY W:o
} 11Y4oS
s<b(@L 1
9_&N0>OF
public void setSSiteURL(String value) U3rpmml
{ RGC DC*\
sSiteURL = value; 3zsjL=ta
} 032PR;]
A` )A=L
eZ`x[g%1
public String getSFilePath() qQ^bUpk0
{ FS^ie|8{D-
return sFilePath; )>+J`NFa
} _Y8RP%
Cu-z`.#}R
^>/] Qi
public void setSFilePath(String value) u[b0MNE~
{ h5p,BRtu
sFilePath = value; `ZELw=kLL
} nR#'BBlI
-D^.I
+|c1G[Jh
public String getSFileName() eGE[4Z
{ b8~7C4
return sFileName; 'joE-{
} {+@M!
/`H{n$
34s>hm=0.
public void setSFileName(String value) lDF26<<\`
{ a&)4Dv0
sFileName = value; LP:U6 Z
} Ew$-,KC[
bG&vCH;}%
c8}jO=/5+
public int getNSplitter() nX\Q{R2
{ biy[h3b
return nSplitter; N3SB-E+
} F2WMts
i8 fUzg)
+~l`rJ
public void setNSplitter(int nCount) @(I)]Ca%O
{ r]yI5 ;
nSplitter = nCount; YH-+s
} FTT=h0t
} Y1s3>`
jQRl-[n
NoD\t(@h
/* ;{S7bH'6m
**Utility.java wfY]J0l
*/ ,`.`}'
package NetFox; w8298Kl
^/_1y[j
.In8!hjYy4
public class Utility { <h[l)-86
u(bPdf@kz
5l,Q=V^@l
public Utility() yE>f.|(
{ +8eW/Bs@2
l.AG^b
i48Tb7Rx~n
} ~ s# !\Ye
le.(KgRS4
//线程睡眠 bc ;(2D
public static void sleep(int nSecond) >^(Q4eU7!
{ 3E`poE
try{ |C_sP,W
Thread.sleep(nSecond); Tj_~BT
} VSQxlAGk@
catch(Exception e) O({vHqN>
{ <h<4R Rj
e.printStackTrace (); -Ka0B={Z
} dd|/I1
} T*irCe
w$)E#|i
//日志 6z>Zm1h
public static void log(String sMsg) "F8A:tR
{ 8"2X 8C8
System.err.println(sMsg); .pd_SQ~
} L7 f'
dt=5 Pnf[y
dX>l"))yR
public static void log(int sMsg) N,Ys}qP
{ "H!2{l{
System.err.println(sMsg); L.1pO2zPe
} Bp:i[9w
} a eo/4
BR[f{)a5
b*@y/ e\u`
/* ?iQA>P9B
**TestMethod.java f7Fr%*cO
*/ 4RU/y+[o
package NetFox; i~04P
~e@pL*s
+w'{I`QIL0
public class TestMethod { jhmWwT/O8^
*[?DnF+
n^m6m%J)
public TestMethod() M.QXwIT
{ ///xx/weblogic60b2_win.exe =|G l
try{ glvtumv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #6 yi
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); //\UthOT
SiteFileFetch fileFetch = new SiteFileFetch(bean); &:ib>EB03=
fileFetch.start(); |Lz:i+;
} wtL_c
catch(Exception e){e.printStackTrace ();} cr_Q,*
2n`OcXCh/
#Kp/AN5YC
} oztfr<cUH
std4Nyp
sG~5O\,E
public static void main(String[] args) bWAVBF
{ u teI[Q
new TestMethod(); (&x#VmDL
} K[(h2&
} &v#*
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