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)); G2 xYa$&][
} E!C~*l]wJx
for(int i=0;i<nEndPos.length-1;i++) f.Q?-M
{ 0'c<EJ
nEndPos = nStartPos[i+1]; =HYMX"s
} _av%`bb&z9
nEndPos[nEndPos.length-1] = nFileLength; mzfj!0zR*
} Q3_ia5 `O
} {- 7T\mj
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//启动子线程 ,`S"nq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w'?uJW
for(int i=0;i<nStartPos.length;i++) HaJD2wvr
{ !>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %fK"g2:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DyYl97+Z?
nStartPos,nEndPos,i); J:5%ff~r\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F#O.i,
fileSplitterFetch.start(); onHUi]yYu{
} O9:vPbn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F~)xZN3=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qf(!3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", G{YJ(6etZ
nEndPos = " + nFileLength); %l5Uy??Z
// fileSplitterFetch[nPos.length-1].start(); A!W(>
^h4Q2Mv o
*.ZV.(
//等待子线程结束 P;mmK&&
//int count = 0; )7*Apy==x
//是否结束while循环 f)?s.DvUB
boolean breakWhile = false; po\QMe
cQS}pQyYN
s:i$s")
while(!bStop) BVC\~j j
{ }V6}>!Sb
write_nPos(); 9iUkvnphh
Utility.sleep(500); qwiM.b5
breakWhile = true; 6 @'v6 1'
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for(int i=0;i<nStartPos.length;i++) rnEWTk7&
{ 57%:0loW
if(!fileSplitterFetch.bDownOver) "72 _Sw
{ 7f~.Qus
breakWhile = false; QU8?/
break; h9 [ov)
} \b{=&B[Q$'
} Pdrz lu
if(breakWhile) zG+oZ
break; kYmkKl_
Ag#p)
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//count++; N=)N
//if(count>4) maXQG&.F
// siteStop(); Q<wrO
} (VU: &.
;~tKNytD`B
HwiG~'Ah9
System.err.println("文件下载结束！"); SI4M<'fK
} o%RyE]pw,
catch(Exception e){e.printStackTrace ();} AL3zE=BL
} {[NBTT9&
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dl;^sn0s
//获得文件长度 n;/yo~RR
public long getFileSize() )Uo)3FAn
{ qIuY2b`6
int nFileLength = -1; NIQNzq?a^
try{ bTb|@
URL url = new URL(siteInfoBean.getSSiteURL()); nH/V2>Lm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5ju\!Re3X
httpConnection.setRequestProperty("User-Agent","NetFox"); =Pd3SC})6V
|J?KHI
[8l8m6
int responseCode=httpConnection.getResponseCode(); vRVQ:fw
if(responseCode>=400) #L`@["
{ A)/_:
processErrorCode(responseCode); QUH USDT
return -2; //-2 represent access is error <t.yn\G-w
} kOs_]
@m<xpel
[qI, $ +
String sHeader; bmGIxBRq
o/)]z
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for(int i=1;;i++) ")i4w{_y
{ pbl;n|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E&7U |$
//Utility.log(in.readLine()); [59_n{S 1
sHeader=httpConnection.getHeaderFieldKey(i); 5)AMl)
if(sHeader!=null) %f*8JUE16
{ ?qO_t;:0>
if(sHeader.equals("Content-Length")) Dc}-wnga
{ q~T*R<S
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !Hr~B.f7
break; nulVQOj|
} '[I?G6
} hDSt6O4za
else l> W?XH
break; ?|w>."F
} d3St Z~&r!
} `DUMTFcMX
catch(IOException e){e.printStackTrace ();} 'W@X139zq
catch(Exception e){e.printStackTrace ();} ;vy"i
f)Z$,&
p?>(y
Utility.log(nFileLength); &&nvv&a
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[h {zT)[
return nFileLength; V<*PaS..
} p$`71w)'[
[sy~i{Bm
0L S,(v4
//保存下载信息（文件指针位置） 3-`IMNn!
private void write_nPos() ; {iX_%
{ y U =) g
try{ TMpV.iH
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1I{vBeMj
output.writeInt(nStartPos.length); |Rd?s0u
for(int i=0;i<nStartPos.length;i++) -r@fLkwg
{ sn+g#v9e
// output.writeLong(nPos); ^KM' O8
output.writeLong(fileSplitterFetch.nStartPos); wDVKp['
output.writeLong(fileSplitterFetch.nEndPos); bC{}&a
} >7V96jL$Y
output.close(); ^Vso`(Ss
} ~k^rIjR
catch(IOException e){e.printStackTrace ();} (y*7 gf
catch(Exception e){e.printStackTrace ();} aY@]mMz\
} LP-~;
HIsIW%B
W8z4<o[$
//读取保存的下载信息（文件指针位置） O3/][\
private void read_nPos() A<fKO <d
{ ;4>YPH
try{ I8TqK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MKf|(6;~
int nCount = input.readInt(); ?x1sm"]p'
nStartPos = new long[nCount]; _~/F-
nEndPos = new long[nCount]; SR!EQ<
for(int i=0;i<nStartPos.length;i++) _2xNio&
{ -K eoq
nStartPos = input.readLong(); z6)b XL[f
nEndPos = input.readLong(); m!Cvd9X=
} }Go?j# !
input.close(); d,8L-pT$FM
} ' ^E7T'v%
catch(IOException e){e.printStackTrace ();} VHyH't_&s
catch(Exception e){e.printStackTrace ();} X'Q?Mh
} ]Wr2IM
<`rmQ`(}s
%A64AJZ
private void processErrorCode(int nErrorCode) KSDz3qe
{ b+Sq[
System.err.println("Error Code : " + nErrorCode); VwvL
} `?f6~$1
+O"!*
Zgy~Y0Di
//停止文件下载 _N)/X|=~s
public void siteStop() tg-U x
{ >9dzl#
bStop = true; 17P5Dr&
for(int i=0;i<nStartPos.length;i++) q)te/J@
fileSplitterFetch.splitterStop(); i^T@jg+K
D+m#_'ocL
_/V<iv
} (KxI*
} C# zYZ JZ
//负责部分文件的抓取 1Xzgm0OS;
**FileSplitterFetch.java QTr)r;Tro
*/ VaP9&tWXj
package NetFox; 4PK/8^@7)>
uDD{O~wF,
E+z),"QA
import java.io.*; + OKk~GYf
import java.net.*; k;/K']4y
TWE>"8]
2iM]t&^<+
public class FileSplitterFetch extends Thread { I\e/ Bv^
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String sURL; //File URL )|3BS`
long nStartPos; //File Snippet Start Position B|d-3\sn
long nEndPos; //File Snippet End Position Y*VF1M,2_
int nThreadID; //Thread's ID 3bYPi^
boolean bDownOver = false; //Downing is over &s6;2G&L$
boolean bStop = false; //Stop identical b'q ru~i
FileAccessI fileAccessI = null; //File Access interface X* 4C?v
I+2#k\y
xmVW6 ,<?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H=lzW_(
{ ?vt#M^Q
this.sURL = sURL; aa2 vk)~
this.nStartPos = nStart; o8_))
this.nEndPos = nEnd; W(5XcP(
nThreadID = id; M>qqe!c*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^_\S)P2c
} uA-1VwW+N
S)LvYOOB@
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public void run() 4y*"w*L
{ '+EtnWHs
while(nStartPos < nEndPos && !bStop) (aC~0 #4
{ `D/<*e,#
W&~\@j]!D
=[JstiT?E
try{ ycq+C8J+Ep
URL url = new URL(sURL); n(uzqd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b~$8<\
httpConnection.setRequestProperty("User-Agent","NetFox"); |j}D2q=
String sProperty = "bytes="+nStartPos+"-"; b:WA}x V
httpConnection.setRequestProperty("RANGE",sProperty); k3(q!~a:.}
Utility.log(sProperty); QmgO00{
lA{JpH_Y8s
h;Hg/jv
InputStream input = httpConnection.getInputStream(); [KQ#b
//logResponseHead(httpConnection); MO^Q 8v
^>wlj
3</W}]$)p
byte[] b = new byte[1024]; M^ZEAZi
int nRead; p40;@gUug
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2Tp@;[!3
{ zMke}2
nStartPos += fileAccessI.write(b,0,nRead); FEH+ PKSc
//if(nThreadID == 1) _C@A>]GT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?K\r-J!Y
} MgO_gFr
< ]"Uy p
p[Zk;AT~
Utility.log("Thread " + nThreadID + " is over!"); %W}YtDf\
bDownOver = true; hbdB67,
//nPos = fileAccessI.write (b,0,nRead); Mfn^v:Q#
} )%q!XM
catch(Exception e){e.printStackTrace ();} Tw,|ZA4XH
} 6E@TcN~,!
} |A.nP9hW
dVMduo
Sx:JuK@
//打印回应的头信息 `+h+X9
public void logResponseHead(HttpURLConnection con) mxnu\@}(
{ dQn,0
for(int i=1;;i++) =AcK9?%5
{ w=_q<1a
String header=con.getHeaderFieldKey(i); HTLS$o;Q
if(header!=null) +iqzj-e&e[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1B#iJZ}
Utility.log(header+" : "+con.getHeaderField(header)); `@xnpA]l
else f AY(ro9Q(
break; 7@R^B=pb
} LC7%Bfn!
} o2D;EUsNX
,|g&v/WlC%
)[ QT?;
public void splitterStop() qeDXG
{ :yw8_D3
bStop = true; "!Qi$ ]
} b@S~ =
7{tU'`P>
wg+[T;0S
} j#~ S"t
ov<vSc<u
O7]kcA
/* nx(jYXVT
**FileAccess.java T[evh]koB
*//文件访问(定位，写) H|S hi/
package NetFox; }uwZS=pw
import java.io.*; 3*T/ 7\
C|V5@O?;&
:N!s@6
public class FileAccessI implements Serializable{ .,sbqL
O5MV&Zb(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "574%\#4z
RandomAccessFile oSavedFile; #qu;{I#W3
long nPos; ]SAGh|+xl
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!LQzf(s;
public FileAccessI() throws IOException I<Cm$8O?
{ 9n49p?
this("",0); GkxQEL
} "Lyb4#M
^6gEL~m|]
G6}!PEwM
public FileAccessI(String sName,long nPos) throws IOException f%3MDI
{ /2''EF';
oSavedFile = new RandomAccessFile(sName,"rw"); mBEMwJ}O`
this.nPos = nPos; ]Exbuc
oSavedFile.seek(nPos); k]A=Q
} nq,:UYNJ
R, #szTu
8`s*+.LI!
public synchronized int write(byte[] b,int nStart,int nLen) _%3p&1ld
{ XqU0AbQ
int n = -1; FJqg,
try{ Aj]/A
oSavedFile.write(b,nStart,nLen); Lf:#koaC
n = nLen; guVuO
} yf[1?{iVo
catch(IOException e) beBv|kI4
{ ^;K"Y'f$
e.printStackTrace (); >(_2'c*[w
} +xAD;A4
-'}#j\
_>a`dp.19
return n; yRi5t{!V
} mo9(2@~<
$> ;|
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} 39m8iI%w[
vTo+jQs^
bxPJ5oT
/* A>,kmU5
**SiteInfoBean.java 3kh!dL3D
*/ k%8kt4\wn6
package NetFox; M;W&#Fz%
03AQB;.
3s?ZyQy
public class SiteInfoBean { KYyoN
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>sdF:(JV&
private String sSiteURL; //Site's URL #S]O|$&*
private String sFilePath; //Saved File's Path *%\Xw*\0
private String sFileName; //Saved File's Name XZQ-Ig18
private int nSplitter; //Count of Splited Downloading File m^zD']
;pS+S0U
?&!!(dWFH
public SiteInfoBean() ++UxzUd
{//nSplitter的缺省值为5 FRL;fF
//default value of nSplitter is 5 txm6[Io
this("","","",5); 'f0R/6h\3s
} gV$0J?Pr.
I FvigDj?
T*S)U ;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EuA352x
{ ?9 W2ax-4
sSiteURL= sURL; eoFG$X/PO
sFilePath = sPath; dNCd-ep
sFileName = sName; 's5H_ah
this.nSplitter = nSpiltter; K47.zu
,<C~DSAyZ
[vz2< genn
} ?)[=>Kp
Sj:c {jyJd
GY5JPl
public String getSSiteURL() xOr"3;^
{ O>I%O^
return sSiteURL; a^^OI|?
} Ted tmX$
<WbO&;%
S;/pm$?/
public void setSSiteURL(String value) !]9qQ7+R%
{ tR4+]K
sSiteURL = value; >p#_L^oZ%
} OlptO60{ ]
*=]UWM~]
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public String getSFilePath() fGW~xul_
{ Ic^ (6
return sFilePath; ~OLyG$JJ
} ,,1y0s0`
(w+SmD
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public void setSFilePath(String value) T!pA$eE
{ :o87<) _F
sFilePath = value; +;*4.}
} ^jcVJpyT@R
(LMT'
4N1)+W8k*
public String getSFileName() ;5
{ 5Q:49S47
return sFileName; t\PSB
} X)=m4\R
n 4cos
hQz1zG`z7
public void setSFileName(String value) naA8RD5/
{ sO!m,pK(
sFileName = value; ~9,Fc6w4`+
} sHV?njZd
loHMQKy@
\4 +HNy3
public int getNSplitter() `,Y3(=3Xe?
{ rmFcSolt,f
return nSplitter; 0-uVmlk=/
} \IEuu^
|oePB<N
\@T;/Pj{[
public void setNSplitter(int nCount) sPl3JP&s
{ {qU;>;(
nSplitter = nCount; h0A%KL
} &" 5Yt&{
} hBifn\dFr
'Q=(1a11
DeeV;?:
/* }AiF 7N0
**Utility.java ;#8xRLW
*/ FF7?|V!Q
package NetFox; eLV[U
obv_?i1
(yeWArQ
public class Utility { ]US!3R^
AM#s2.@
:QHh;TIG=<
public Utility() ,g3n/'rP%
{ !/!Fc'A
E8wkqZN
L$"pk{'
} a]6dhQ`
>svx 8CT
//线程睡眠 1zCgPiAem
public static void sleep(int nSecond) 79k+R9m
{ P?jI:'u!R.
try{ NF-@Q@
Thread.sleep(nSecond); 4af^SZ)l
} `D$RL*C;M`
catch(Exception e) [A] +Azc
{ A!uiM*"W
e.printStackTrace (); Jp_ :.4
} r Cz,XYV
} tWQ$`<h
Qw"%Xk
//日志 (.wR!l#!
public static void log(String sMsg) \NKw,`/
{ Q)8I(*
System.err.println(sMsg); H:WuMwD4
} M6V^ur 1
dYlVJ_0Zr
dl`{:ZR S
public static void log(int sMsg) 9A|9:OdG1
{ )t:8;;W@Ir
System.err.println(sMsg); ;<%th
} ~LP5hL
} %F}d'TPx
F ^m;xy
WA*1_
/* M!%|IKw
**TestMethod.java -3m!970
*/ t8.3
package NetFox; |eJR3o
I SdB5Va
Im]6-#(9\|
public class TestMethod { @~&^1%37)
gkca{BJ
qagR?)N)u
public TestMethod() U]9k,#
{ ///xx/weblogic60b2_win.exe >McEuoZx9
try{ b?,=|H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ov >5+"q)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K*p3#iB
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3BF3$_u)o
fileFetch.start(); 4AF.KX7
} `joyHKZI.
catch(Exception e){e.printStackTrace ();} Wdga(8t
b dC
2i NZz
} I\Cg-&e
"{2niBx
O.8k [Ht
public static void main(String[] args) 1?Tj
{ 8]bLp
new TestMethod(); h2i1w^f
} #)iPvV'
} {.e^1qE
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