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)); @as"JAN
} r}uz7}z %"
for(int i=0;i<nEndPos.length-1;i++) pABs!A`N
{ Oft4-4$E
nEndPos = nStartPos[i+1]; ]E]2o
} TLoz)&@
nEndPos[nEndPos.length-1] = nFileLength; >yY'7Ey
} :1Q!$ m
} detwa}h[0
{uGP&cS~(
+-E~6^>
//启动子线程 w`q%#qRk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SPp#f~%m
for(int i=0;i<nStartPos.length;i++) ?_I[,N?@41
{ 'uq#ai[5I
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1KjU ] r2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bQ~j=\[r
nStartPos,nEndPos,i); ` AY_2>7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qIld;v8w"g
fileSplitterFetch.start(); ?JL:CBvCp
} ~#kT_*sw)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K~22\G`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ot]Ru,y->+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V*W;OiE_3
nEndPos = " + nFileLength); b$Vz2Fzx
// fileSplitterFetch[nPos.length-1].start(); W"Gkq!3u{
G#MdfKH
1x[)/@.'f
//等待子线程结束 }!6\|;Qsz,
//int count = 0; Uh][@35 p
//是否结束while循环 Br`IW
boolean breakWhile = false; 3Kn_mL3V-
/{|fyKo\?
cq$i
while(!bStop) {l |E:>Q2
{ [ :zO}r:
write_nPos(); YX`7Hm,
Utility.sleep(500); p1vp8p
breakWhile = true; gCxAG
X,LD
Ntbg`LGf'!
for(int i=0;i<nStartPos.length;i++) 8cA~R-
{ A\#iXOd
if(!fileSplitterFetch.bDownOver) &8z[`JW,T
{ P LueVz
breakWhile = false; "I QlVi
break; AZmb!}m+d
} %?m$`9yU
} Y*!qG
if(breakWhile) qM.bF&&Go
break; #y%!\1M/:A
^.>jGI%rB
Yh>]-SCw
//count++; ?yj6CL(,
//if(count>4) wR^RM(1
// siteStop(); W16,Alf:
} C?2'+K
ndeebXw*
fXcm|U,ho
System.err.println("文件下载结束！"); 65Cg]Dt71
} >Bgw}PI
catch(Exception e){e.printStackTrace ();} X_7UJ jFw"
} |M+<m">E
n-%s8aaVf
a|?4)
//获得文件长度 YiPoYlD*n<
public long getFileSize() Y_QH&GZ
{ q5#J~n8Wr
int nFileLength = -1; kP?KXT3y
try{ Q*b]_0Rb
URL url = new URL(siteInfoBean.getSSiteURL()); Cm\6tD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'UYR5Y>
httpConnection.setRequestProperty("User-Agent","NetFox"); HTyLJe
?!`=X>5
9F*+YG!
int responseCode=httpConnection.getResponseCode(); %b"\bHH
if(responseCode>=400) z5r$M
{ Ck!VV2U#
processErrorCode(responseCode); )lZp9O
return -2; //-2 represent access is error J52 o g4l
} />9OR
Iwc{R8BV
EMfdBY5
String sHeader; !H}vu]R
afb+GA!
J;f!!<l\
for(int i=1;;i++) uECsh2Uin
{ #jxe%2'Ot
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k+DR]icv
//Utility.log(in.readLine()); ]._LLSzWhg
sHeader=httpConnection.getHeaderFieldKey(i); a!u rew#
if(sHeader!=null) }sOwp}FV8X
{ [NTtz <i@
if(sHeader.equals("Content-Length")) (bh95X
{ :bC40@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d:i;z9b@to
break; ti<;7Yb
} :G<E^<M\)^
} PK4iuU`vh
else 44F`$.v96
break; ?:L:EW8
} xQp|;oW;z
} 4~N[%>zJ
catch(IOException e){e.printStackTrace ();} {U_$&f9s
catch(Exception e){e.printStackTrace ();} 3hK#'."`N
\l@,B +)
T0]*{k(FR
Utility.log(nFileLength); zD?K>I=
Jzp#bgq}|
bpxeznz
return nFileLength; Y}vr>\
} Al`e/a
!0dNQ[$82
+ Q6l*:<|c
//保存下载信息（文件指针位置） qVs\Y3u(
private void write_nPos() MXyaE~LK
{ d`(@_czdF
try{ gc?#pP
output = new DataOutputStream(new FileOutputStream(tmpFile)); _IdRF5<4
output.writeInt(nStartPos.length); p}<w#p |
for(int i=0;i<nStartPos.length;i++) d%0~c'D8a
{ r]0 lo-
// output.writeLong(nPos); YX_gb/A
output.writeLong(fileSplitterFetch.nStartPos); 7k(Kq5w.
output.writeLong(fileSplitterFetch.nEndPos); UDL RCS8i
} 5P'p2x#U
output.close(); ScSZGs 5&
} "hy.GWF|*
catch(IOException e){e.printStackTrace ();} W mm4hkf
catch(Exception e){e.printStackTrace ();} Z?O*'#yn
} WsDM{1c
np4+"
{H{X[p8
//读取保存的下载信息（文件指针位置） A=j0On
private void read_nPos() LB.co4
{ ?Q72;/$
try{ {Ions~cO)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Tdc3_<1
int nCount = input.readInt(); _Um d
nStartPos = new long[nCount]; {$1J=JbE
nEndPos = new long[nCount]; G\a8B#hg
for(int i=0;i<nStartPos.length;i++) ez9q7SpA
{ L-9~uM3@\
nStartPos = input.readLong(); A%2:E^k(s
nEndPos = input.readLong(); +GAf O0
} \t|M-%&)4
input.close(); 1* ]Ev
} PTS]7
catch(IOException e){e.printStackTrace ();} aBzszp]l+
catch(Exception e){e.printStackTrace ();} c1xrn4f@a
} [JaS??ig
wWXD\{Hk
@;?T~^nGj
private void processErrorCode(int nErrorCode) k'PQ} ,Vb
{ W@2vjz
System.err.println("Error Code : " + nErrorCode); -`Y:~q1
} SZ_V^UX_
BJS-Jy$-
&ciN@nJ|$z
//停止文件下载 U/NBFc:[y:
public void siteStop() O$ HBO
{ 4R8G&8b
bStop = true; emW:C-/h/@
for(int i=0;i<nStartPos.length;i++) j.:h5Y^N
fileSplitterFetch.splitterStop(); dr<<!q /
RJeSi`19T)
"+uNmUUnm
} Y+qQIMZ
} dz[ bm<T7
//负责部分文件的抓取 }!i`0p
**FileSplitterFetch.java Em7 WDu0
*/ y3<Y?M4
package NetFox; F6hmku>\1
4"=Vq5
LG]3hz9^9
import java.io.*; 9,]5v+
import java.net.*; ejXMKPE;
V|>oGtt7
A%\tiZe
public class FileSplitterFetch extends Thread { BN,>&1I
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$t-n'Qh^2
String sURL; //File URL $c&0F,
long nStartPos; //File Snippet Start Position G9g6.8*&
long nEndPos; //File Snippet End Position ^ZTGJ(j7~
int nThreadID; //Thread's ID 0qFH s
boolean bDownOver = false; //Downing is over 4ujvD^
boolean bStop = false; //Stop identical l =IeJh
FileAccessI fileAccessI = null; //File Access interface l?*r5[O>n
2-0$FQ@/
5y4u5Tm-%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s:y ^_W)d
{ X%9*O[6{
this.sURL = sURL; b.2J]6G
this.nStartPos = nStart; pe&UQ C^
this.nEndPos = nEnd; e1q"AOV6
nThreadID = id; +[.Yy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;pRcVL_4
} $WW)bP d4^
B ?%L
C+NF9N
public void run() )fU(AXSP
{ 8n?kZY$,
while(nStartPos < nEndPos && !bStop) %"A_!<n@*`
{ )yxT+g2!
dv N<5~
'q%%m/,VPQ
try{ ?PPZp6A3L=
URL url = new URL(sURL); tu%[p 4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #NRh\Wj|
httpConnection.setRequestProperty("User-Agent","NetFox"); <Mf*l)%*
String sProperty = "bytes="+nStartPos+"-"; gmSQcN)
httpConnection.setRequestProperty("RANGE",sProperty); Wf>^bFb"$
Utility.log(sProperty); +'03>!V
mxqG-*ch-
#%S0PL"x U
InputStream input = httpConnection.getInputStream(); Q*O<@
//logResponseHead(httpConnection); X,v4d~>]
+3^NaY`Y
]re'LC!d
byte[] b = new byte[1024]; %"Db?
int nRead; XrN- 2HTV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ms~8QL
{ Ttv9"z
nStartPos += fileAccessI.write(b,0,nRead); C9KWa*3
//if(nThreadID == 1) ]HvZ$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !Ua&0s%
} E20 :uZ7\
Dl;d33
&2.+Igo|G
Utility.log("Thread " + nThreadID + " is over!"); F,v7ifo#f
bDownOver = true; p#H]\P'
//nPos = fileAccessI.write (b,0,nRead); ]h~o],:
} 93w~.p
catch(Exception e){e.printStackTrace ();} *_)E6Y?9
} ^Omfe
} n,KA&)/s
l_+A5Xy
<TjBd1
//打印回应的头信息 ^Rmoz1d
public void logResponseHead(HttpURLConnection con) eoJ]4-WFq
{ S;}qLjT
for(int i=1;;i++) ac6*v49
{ .[f;(WR
String header=con.getHeaderFieldKey(i); JE)J<9gf
if(header!=null) oCJbkt=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RG?MRxC
Utility.log(header+" : "+con.getHeaderField(header)); K+mU_+KRp
else /2h][zrZ[.
break; 2z-$zB<vyw
} u33zceE8
} ;c)! @GoA
.;slrg(5F
^K*-G@B
public void splitterStop() 8_iHVc;<
{ !`C%Fkq
bStop = true; ^Fp=y,D
} |#cAsf_{
m0Z7N5v)
#HDesen
} [|<EDR
{_as!5l
)l{A{f6O
/* -aN":?8(G
**FileAccess.java qvTJ>FILT
*//文件访问(定位，写) `]hCUaV
package NetFox; lEa W7j
import java.io.*; R.UumBM
\^m.dIPdO
+3HPA#A
public class FileAccessI implements Serializable{ 5U;nhDmM
.~22^k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2*YP"Ryh
RandomAccessFile oSavedFile; zP|*(*
long nPos; *JS"(. '(
kc|>Q7~{
^Yr|K
public FileAccessI() throws IOException H8<m9zDvl
{ xBt<Yt"
this("",0); EaCZx
} H-m`Dh5{
F_ _H(}d
s79q5
public FileAccessI(String sName,long nPos) throws IOException sM0c#YK?
{ 4UazD_`'
oSavedFile = new RandomAccessFile(sName,"rw"); `:R-[>5P8
this.nPos = nPos; UCn.t
oSavedFile.seek(nPos); fX""xTNPi
} -D;lS 6
&EGY+p|2Y
@F~0p5I
public synchronized int write(byte[] b,int nStart,int nLen) BQuRHi IV
{ SUo^c1)G
int n = -1; )I?RMR
try{ xV?*!m$V%R
oSavedFile.write(b,nStart,nLen); V!H(;Tuuo
n = nLen; >]^>gUmq
} FE>3 D1\
catch(IOException e) *|@+rbjVC
{ 2[XltjO
e.printStackTrace (); v^;-@ddr
} CN-4-
Wf_CR(
QZ?O;K1|y
return n; S\}?zlV
} zU=YNrn
Jm%mm SYK
+_P8'e%Iy
} TS/Cp{
@pTD{OW?
aX:#'eDB
/* `D4oAx d9
**SiteInfoBean.java omNpE_
*/ 9/FG,9
package NetFox; E`Q;DlXv>
H\ {E%7^h-
poTl|y @
public class SiteInfoBean { te4F"SEf
Nvi Fq
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private String sSiteURL; //Site's URL sg+ZQDF{x
private String sFilePath; //Saved File's Path @Q/x&BV
private String sFileName; //Saved File's Name mx:J>SPA8
private int nSplitter; //Count of Splited Downloading File R|nEd/'<
83\o(
bl$+8!~
public SiteInfoBean() s*aH`M7^0
{//nSplitter的缺省值为5 f37ji
//default value of nSplitter is 5 y;zt_O/
this("","","",5); F_ ,L2J
} J'I1,5(
R.91v4J
JmnBq<&,0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6F@zCv"w
{ $&ex\_W
sSiteURL= sURL; ^2C0oX
sFilePath = sPath; q"{Up
sFileName = sName; oq=?i%'>
this.nSplitter = nSpiltter; BM|-GErE
jl;kcGE
|h#DL$
} = 4BLc
73'U#@g6
*37LN
public String getSSiteURL() ,[Dh2fPM,
{ WF+bN#YJ
return sSiteURL; R88(dEK
} 4RK.Il*d
${jA+L<J
?l)}E
public void setSSiteURL(String value) dNR7e
{ 2E@C0HaL
sSiteURL = value; c%q}"Y0oh
} ?&whE!
_7-"VoX
:pA=V
public String getSFilePath() Y|hzF:ll
{ &Iv\jhq
return sFilePath; fK)ZJ_?w,@
} ZTQ$Ol+{q
hN>('S-cq
[(D}%+2
public void setSFilePath(String value) t-v^-#
{ (hhdbf
sFilePath = value; #U?EOm
} gE-w]/1zD5
"@c';".|
H3 A]m~=3
public String getSFileName() *eJhd w*
{ ;a!h.8UJPI
return sFileName; %4|n-`:
} 2.HZ+1
USnD7I/b
*3w/`R<\
public void setSFileName(String value) ,wry u|7"$
{ ;55tf l
sFileName = value; F8|5_214'
} g(@$uJ
u7WTSL%
wzNt c)~i
public int getNSplitter() Xa?6#
{ :=iM$_tp'
return nSplitter; h-?q6O/|
} 2;Y@3d:z
%#S"~)
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public void setNSplitter(int nCount) Ru vG1"
{ dCoi>PO
nSplitter = nCount; v2Qc}o
} ])$."g
} >'2w\Uk~:
t]u(jX)
m>Z\ rqOK
/* 8Y{}p[UFT
**Utility.java ^;Hi/KvM\
*/ !"Oj$c -
package NetFox; Dvq*XI5
)L(d$N=Bd
!F7EAQn{(
public class Utility { \ ]kb&Qw
[FAOp@7W
}]39 iK`w
public Utility() >DL-Q\U
{ iZkW+5(
<mo^Y k3
[A%e6
} u':0"5}
11@2;vw
//线程睡眠 ?ck^? p7
public static void sleep(int nSecond) D|Ihe%w-
{ ;@7#w
try{ o trTrh
Thread.sleep(nSecond); zZ+LisSs&
} |bG[TOa
catch(Exception e) z)<pqN
{ 2=/g~rp*
e.printStackTrace (); ]/VIff
} [y=$2
} "-j@GCme
tEWj}rX
//日志 9a~BAH,j
public static void log(String sMsg) 9tc@
{ R0YC:rAt
System.err.println(sMsg); &PQ{e8w
} Vg [5bJ5
EhP&L?EL
RP@idz
public static void log(int sMsg) xU\:Vid+A
{ 48&KdbGX
System.err.println(sMsg); 1(;33),P8
} ++{+ #s6
} [>Kxm
sm&rR=b
|_xiG~
/* &A5[C{x
**TestMethod.java y1"^S
*/ #u=O 5%.
package NetFox; .&yWHdQC:
|z7Crz
u,SX`6%
public class TestMethod { P2:Q+j:PX
?xTeio44
M"$RtS|h
public TestMethod() q!oZ; $
{ ///xx/weblogic60b2_win.exe @ H`QLm
try{ R?9Plzt5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); e/% ;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kFa?q}47
SiteFileFetch fileFetch = new SiteFileFetch(bean); x#gmliF
fileFetch.start(); J%[N-
} .HyiPx3^
catch(Exception e){e.printStackTrace ();} . ;@)5"
,l?76g
a3 _0F@I
} a5~C:EU0
:ktX7p~
]jY)M<:J4
public static void main(String[] args) y`@4n.Q
{ ieF 0<'iF
new TestMethod(); j83Y'VJJC
} 'nDT.i
} r|F,\fF
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