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)); q2et|QCru
} fOMvj%T@2
for(int i=0;i<nEndPos.length-1;i++) I:d[Q s
{ :=[XW?L%x
nEndPos = nStartPos[i+1]; n8DxB@DI
} KFFSv{m[
nEndPos[nEndPos.length-1] = nFileLength; ?IGVErnJJC
} g'|MA~4yB
} 3dRr/Ilc
cJL'$`gWf
4`8<
//启动子线程 ?A )hN8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &[;HYgp
for(int i=0;i<nStartPos.length;i++) 6A=8+R'`F
{ 1M}&ZH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :G<E^<M\)^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !1G."fo
nStartPos,nEndPos,i); S!sqbLrBn
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W<E47
fileSplitterFetch.start(); h@LHRMO
} jWYV#ifs2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n2IV2^ "
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 17OH]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -G|G_$9
nEndPos = " + nFileLength); w#g#8o>'
// fileSplitterFetch[nPos.length-1].start(); W[}s o6
&CG*)bE
vVgg0Y2
//等待子线程结束 e@ \p0(
//int count = 0; QurW/a
//是否结束while循环 ZPD[5)~
boolean breakWhile = false; Cj?L@%"
RJ$7XCY%`*
FSRj4e1y1
while(!bStop) Kk{<@v)
{ uSR~@Lj ~
write_nPos(); NoJ`6MB
Utility.sleep(500); NmSo4Dg`U
breakWhile = true; }nMPSerE
,DZX$Ug~+E
leQT-l2Bk
for(int i=0;i<nStartPos.length;i++) 59Gk3frk(
{ 7H|$4;X^
if(!fileSplitterFetch.bDownOver) 5Fz.Y}
{ Q"7Gy<
breakWhile = false; (~J^3O]Fo
break; 4DOK4{4?5
} |#*'H*W
} o#hjvg
if(breakWhile) L*x[?x;)@
break; nw6+.pOy
YLVPAODY
Y9`5G%
//count++; t&(PN%icD
//if(count>4) gy;+_'.j
// siteStop(); :Pv*,qHE
} /AQMFx4-5
oy;K_9\
ru7RcYRq
System.err.println("文件下载结束！"); Dxk+P!!K
} B)QHM+[=F
catch(Exception e){e.printStackTrace ();} p3}?fej&|
} po}F6m8bX
6AWKLFMV
{N#KkYH{"
//获得文件长度 A3ZY~s#Iv
public long getFileSize() YQS5P#
{ i>joT><B
int nFileLength = -1; z-c}NdW
try{ Wn>@9"
URL url = new URL(siteInfoBean.getSSiteURL()); MG?0>^F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }E7:ihy
httpConnection.setRequestProperty("User-Agent","NetFox"); ai0Ut
+nT'I!//
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int responseCode=httpConnection.getResponseCode(); TET`b7G
if(responseCode>=400) 2m~V{mUT!
{ 0JD~M\-!^a
processErrorCode(responseCode); FPJd|
return -2; //-2 represent access is error _kY#D;`:r
} W.w)H@]7m
r lKlpl
7K{Nb
String sHeader; 84{Q\c
A%2:E^k(s
mB0l "# F
for(int i=1;;i++) 0n/gd"M
{ 9Mgq1Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /o2P+Xr8"
//Utility.log(in.readLine()); .uEPnzi
sHeader=httpConnection.getHeaderFieldKey(i); bTSL<"(]N
if(sHeader!=null) =GXu 5 8
{ *;XWLd#
if(sHeader.equals("Content-Length")) Y+3!f#exm
{ $:of=WTY(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u@3y&b
break; A?*o0I
} ^xZ e2@
} $v b,P(
else W@2vjz
break; =-o'gL
} Ea(,aVlj
} &k8vWXMGk%
catch(IOException e){e.printStackTrace ();} w;e(Gb%9
catch(Exception e){e.printStackTrace ();} uZi.HG{<)
&,.Y9; b
Ei2%DMN7)
Utility.log(nFileLength); U/NBFc:[y:
I_q~*/<h
')N{wSM9Ft
return nFileLength; A$WZF/x
} ~xIjF1Z
LA[g(i 7
Cbs5dn(Y
//保存下载信息（文件指针位置） =@)d5^<5F
private void write_nPos() S:61vD
{ Oi} T2I
try{ X1vNF|o~
output = new DataOutputStream(new FileOutputStream(tmpFile)); nPUqMn'
output.writeInt(nStartPos.length); k'X;ruQ:tF
for(int i=0;i<nStartPos.length;i++) >Ng)k]G
{ dz[ bm<T7
// output.writeLong(nPos); j:bgR8%e
output.writeLong(fileSplitterFetch.nStartPos); a1j.fA
output.writeLong(fileSplitterFetch.nEndPos); _Zc%z@}
} vEG'HOP
output.close(); 7zTqNnPnf
} a83g\c5
catch(IOException e){e.printStackTrace ();} <*EZ@XoN>
catch(Exception e){e.printStackTrace ();} n$(p-po
} b|5w]<?'
auWXgkwZs/
|7@O($b
//读取保存的下载信息（文件指针位置） AddeaB5<
private void read_nPos() ejXMKPE;
{ *U#m+@\0
try{ T$=4O9G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q7bq
int nCount = input.readInt(); pA4*bO+
nStartPos = new long[nCount]; lHB) b}7E
nEndPos = new long[nCount]; [ REf>_R
for(int i=0;i<nStartPos.length;i++) C}5M;|%3)
{ u? fTL2~
nStartPos = input.readLong(); #?B%Ja% ;W
nEndPos = input.readLong(); 1=2^90
} u z\0cX_
input.close(); q/1Or;iK
} z}Jr^>
catch(IOException e){e.printStackTrace ();} s4H2/EC
catch(Exception e){e.printStackTrace ();} '!1$9o^$
} t_ur&.^SB
A`6ra}U<
)$Z(|M4
private void processErrorCode(int nErrorCode) P;]F=m+*V
{ [hRU&z;W
System.err.println("Error Code : " + nErrorCode); :!zC"d9@
} Vc3mp;6"
gX5&d\y
z{]?h cY
//停止文件下载 #&,H"?"
public void siteStop() rp7W }P+uU
{ #hw/^AaD-
bStop = true; b.2J]6G
for(int i=0;i<nStartPos.length;i++) rgcWRt
fileSplitterFetch.splitterStop(); <f~Fl^^8
Bf4%G,o5
a1N!mQ^
} Wd(86idnc
} }vt%R.u
//负责部分文件的抓取 efz&@|KR
**FileSplitterFetch.java G&f7+e
*/ lnbmoHv
package NetFox; 'YSuQP>
;,OfJ'q^
%G3sjnI;l
import java.io.*; xeTgV&$@
import java.net.*; l|/:Ot
Z"I/ NGiU
MQcr^Y_
public class FileSplitterFetch extends Thread { |Wj;QO$C
>P. 'CU
f0Hq8qAF;^
String sURL; //File URL y:}sD_m0W
long nStartPos; //File Snippet Start Position {fSfq&o
long nEndPos; //File Snippet End Position sNU}n<J-
int nThreadID; //Thread's ID mE#nU(+Ta
boolean bDownOver = false; //Downing is over s* jfMY
boolean bStop = false; //Stop identical ]qw0V
FileAccessI fileAccessI = null; //File Access interface l!IKUzt)7
99iUOw c
hh.Q\qhubB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #-cTc&$O;
{ 0NO1M)HQv
this.sURL = sURL; RM*f|j
this.nStartPos = nStart; 0&fl#]oCE
this.nEndPos = nEnd; /owO@~G
nThreadID = id; #^mqQRpgq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^~L}<]
} ?Hy+'sq[
rlznwfr7+
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public void run() 2>hz_o{5',
{ 2RppP?M!
while(nStartPos < nEndPos && !bStop) V{Q kN7-
{ NyPd5m:
}C(5-7
3#.\
try{ G5'_a$
URL url = new URL(sURL); W."f8ow
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -)w]a{F
httpConnection.setRequestProperty("User-Agent","NetFox"); .`C V^\
String sProperty = "bytes="+nStartPos+"-"; 8V5a%2eV
httpConnection.setRequestProperty("RANGE",sProperty); ;6DnId2Zh
Utility.log(sProperty); \3PE+$
cBEHH4U
t;#Gmo
InputStream input = httpConnection.getInputStream(); zX5G;,_
//logResponseHead(httpConnection); fnH3CE
hG Apuy
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byte[] b = new byte[1024]; #s+X+fe
int nRead; E8-53"m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Rrqg[F+
{ kR6A3?[
nStartPos += fileAccessI.write(b,0,nRead); F!8=FTb
//if(nThreadID == 1) ^@.G,u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vD=%`G[m
} t=dO
`mB.pz[
4#Eul
Utility.log("Thread " + nThreadID + " is over!"); Jyu`-=It
bDownOver = true; mtw9AoO
//nPos = fileAccessI.write (b,0,nRead); g"y?nF.&F
} BXTN>d27
catch(Exception e){e.printStackTrace ();} aR:<<IF\
} LV.&>@*
} [b`6v`x
')nnWlK
(K!4Kp^m
//打印回应的头信息 SFO&=P:U
public void logResponseHead(HttpURLConnection con) D<nxr~pQ
{ !A[S6-18%-
for(int i=1;;i++) c#\-%h
{ ac6*v49
String header=con.getHeaderFieldKey(i); ~Fx&)kegTo
if(header!=null) iVeQ]k(u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ="B n=>
Utility.log(header+" : "+con.getHeaderField(header)); .5g}rxO8
else 7c::Qf[|
break; QHQj/)J8
} %3,xaVN
} ?~)Ak`=
0>Fqx{!heq
Vj!WaN_
public void splitterStop() 0$2={s4ze
{ BW71 s
bStop = true; .Z5[_'T
} $Sb@zLi)
;c)! @GoA
@+dHF0aXd
} oEAfowXSqk
~V$ f#X
eycV@|6u*
/* jYdV?B
**FileAccess.java ;](h2Z`3s
*//文件访问(定位，写) #>q[oie1e
package NetFox; W uf/LKj
import java.io.*; 2v\W1VF
9Dq.lr^
MF|*AB|E
public class FileAccessI implements Serializable{ KnFQ)sX^
IHVMHOq}'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tw86:kYEz
RandomAccessFile oSavedFile; S.]MOB dt
long nPos; )G4rJ~#@
;KS`,<^-
;fx1!:;.
public FileAccessI() throws IOException ]Wy.R6
{ _ _=s'
this("",0); Ps7_-cH
} @Mr}6x*
5Jw"{V?Ak
fKYKW?g;)Z
public FileAccessI(String sName,long nPos) throws IOException HPTHF
{ "GLYyC
oSavedFile = new RandomAccessFile(sName,"rw"); \^m.dIPdO
this.nPos = nPos; LJ l1v
oSavedFile.seek(nPos); =~$U^IsWA
} /h-6CR Ka
tGqQJT#mr7
54wM8'+
public synchronized int write(byte[] b,int nStart,int nLen) .xnQd^qoac
{ Q;@X2JSp
int n = -1; \6LcVik
try{ {9'hOi50
oSavedFile.write(b,nStart,nLen); :f]!O@.~
n = nLen; 7%YYr^d
} kc|>Q7~{
catch(IOException e) (n}%a6M
{ E- KK
e.printStackTrace (); @>CG3`?}
} R ^^1/%
voH4
I1~G$)w#
return n; %Il;B~t
} tgfM:kzw
{a@hRY_
$~TfL{$
} `~|DoSi^d
`%%?zgY
-7,vtd[h
/* gb9[Meg'
**SiteInfoBean.java i&1U4q
*/ _&K\D p&@
package NetFox; gTuX *7w
XX:q|?6_ 4
5{HtJ?sKc5
public class SiteInfoBean { R;.d/U|av
9g4QVo|
jvWI_Fto
private String sSiteURL; //Site's URL 7Qt2gf
private String sFilePath; //Saved File's Path /Q]:Uf.J
private String sFileName; //Saved File's Name Ef-a4Pi
private int nSplitter; //Count of Splited Downloading File BQuRHi IV
f{f_g8f[
!HvGlj@(|
public SiteInfoBean() )I?RMR
{//nSplitter的缺省值为5 y 'mlee
//default value of nSplitter is 5 TXx'7[
this("","","",5); v=j>^FZ
} G u6[{u
>]^>gUmq
Io09W^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 98jD"*W5
{ .r(^h/IF
sSiteURL= sURL; h1E PaL
sFilePath = sPath; FBcm;cjH
sFileName = sName; M,ppCHy/$
this.nSplitter = nSpiltter; ?C FS}v
TJE% U0Ln
{$3j/b
} JUmw$u
Ko]QCLL
8>2&h
public String getSSiteURL() ws.?cCTpt
{ "h QV9 [2\
return sSiteURL; S]vW&r3`
} 6xyY+
FBYll[8
)K8P+zn~
public void setSSiteURL(String value) dEL3?-;'
{ 5Zzr5WM
sSiteURL = value; n#)PvV~
} C0P*D,
aX:#'eDB
5DmCxg
public String getSFilePath() #"|"cYi,
{ iJEB?y
return sFilePath; N\c&PS
} 9/FG,9
keqr%:E8
:EYu 4Y
public void setSFilePath(String value) sbs[=LW4
{ poTl|y @
sFilePath = value; +}kO;\
} Wk7L:uK
};i&a%I|
c6f|y_2
public String getSFileName() @< wYT$
{ |)m*EME
return sFileName; #,7eQaica
} 2O$95M
q;CayN'I
w9/nVu
public void setSFileName(String value) >0kmRVd
{ Czq1 kz
sFileName = value; xX[?L9RGz
} <Z2(qZ^Z
1 ,#{X3
jB5>y&+
public int getNSplitter() kA;xAb+U3
{ \8=e|a5`
return nSplitter; y;zt_O/
} ,:Rft
<jpeu^7
Rrh<mo(yj#
public void setNSplitter(int nCount) m(8jSGV
{ cBg,k[,
nSplitter = nCount; JZWgr&O<
} (y-x01H
} <WZ1-
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x:!C(Ep)
/* SPfD2%jjC
**Utility.java #>7')G
*/ pg}~vb"
package NetFox; ox!|)^`$_
0@II&
(45NZBs
public class Utility { %'RI3gy
fO[Rf_
Cf.pTYSl
public Utility() Y1$#KC
{ 73&]En
MV Hz$hyB
Qw3a"k-
} ,[Dh2fPM,
S4#A#a2J
//线程睡眠 N>uA|<b,
public static void sleep(int nSecond) S^3g]5YX
{ [$hptQv
try{ ~a|^?7@p
Thread.sleep(nSecond); #)W8.
} ?)Tz'9l
catch(Exception e) ?l)}E
{ ^Nd|+}
e.printStackTrace (); dH ^b)G4
} tqff84
} `f\5p+!<7R
c%q}"Y0oh
//日志 J0IdFFZ|w
public static void log(String sMsg) ;FV~q{
{ g`%ED0aR
System.err.println(sMsg); WHlD%u
} |#DC.Ga!
7bgnZ]r8t
.Ws iOJU
public static void log(int sMsg) *6 I =oE
{ ,Hik(22
System.err.println(sMsg); IeRl6r%:
} ZTQ$Ol+{q
} NYSj^k;^(z
-IpV'%nX;
IgzCh
/* sDzD 8as
**TestMethod.java W _PM!>8`
*/ _9}x2uO~
package NetFox; m NUN6qVP~
LU-#=1Q
k7z(Gbzu
public class TestMethod { lU&`r:1>_
"@c';".|
gt2>nTJz.Z
public TestMethod() eEZ|nEU
{ ///xx/weblogic60b2_win.exe K B`1%=
try{ oyKt({
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k#8S`W8^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %4|n-`:
SiteFileFetch fileFetch = new SiteFileFetch(bean); _'?8s6 H
fileFetch.start(); RT.wTJS;
} WU+Jo@]y
catch(Exception e){e.printStackTrace ();} "}]GQt< F
EWuiaw.
_0DXQS\
} beN>5coP%A
"6`)vgI~
wu&|~@_s@
public static void main(String[] args) 'T&=$9g7
{ ? e9XVQ*
new TestMethod(); P+*rWJ8gQ
} y]z)jqX<
} ?1-n\ka
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