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)); 1Tkz!
} 3iwZUqyq
for(int i=0;i<nEndPos.length-1;i++) 4,8 =[
{ |'#NDFI>}
nEndPos = nStartPos[i+1]; 0}!lN{m?
} *?\Nioii
nEndPos[nEndPos.length-1] = nFileLength; <#Dc(VhT
} 0cVXUTJ|W
} K>~l6
S6I8zk)Z4
>^}z
//启动子线程 ~{{:-XkVB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; oyY,uB.|
for(int i=0;i<nStartPos.length;i++) cgAcAcmY
{ }P#gXG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), igCtq!.a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %kT:"j(xW
nStartPos,nEndPos,i); ~I74'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +g&W423k_
fileSplitterFetch.start(); jHzb,&
} 6cvm\opH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4kEFbzwx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); otx7J\4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e)8iPu ..
nEndPos = " + nFileLength); bv0 %{u&
// fileSplitterFetch[nPos.length-1].start(); I Cs1=
vhW'2<(
?*0kQo'
//等待子线程结束 -fv.ByyA
//int count = 0; J %t1T]y~
//是否结束while循环 jrR~V* :k
boolean breakWhile = false; ycN_<
Q)/q h;Ru
-0{WB(P
while(!bStop) ZVL0S{V-mh
{ "-oC,;yq
write_nPos(); 6fiJ' j@
Utility.sleep(500); .[! ^L
breakWhile = true; |iI`p-L9
_!ed.h.r:
;K!Or
for(int i=0;i<nStartPos.length;i++) Z:{Z&HQC
{ Z^'; xn
if(!fileSplitterFetch.bDownOver) 195(Kr<5$
{ $qqusa}`K
breakWhile = false; jEadVM9
break; S/|8'x{<
} ]Yy Sf
} P!/8
if(breakWhile) uQlVzN.?
break; Fk\xq`3'c
<|@9]>z
_rv_-n]"o
//count++; (46)v'?
//if(count>4) bPEAG=l"-
// siteStop(); ,>Q,0bVhH0
} l)Hu.1~
*!/9?M{p
C*$/J\6xy
System.err.println("文件下载结束！"); +q;^8d>
} v3B ^d}+.
catch(Exception e){e.printStackTrace ();} 3 V<8
} ,3K?=e2
B.o&%5dG
0IZV4{
//获得文件长度 sQkP@Y
public long getFileSize() sYL+;(#t
{ QB7<$Bp
int nFileLength = -1; Z=xrjE
try{ bF.Aj8ZQ
URL url = new URL(siteInfoBean.getSSiteURL()); 1/ HofiIa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \n5,!,A
httpConnection.setRequestProperty("User-Agent","NetFox"); \Z$*8z=
Z7Kc`9.0|
)`)cB)s
int responseCode=httpConnection.getResponseCode(); ZO,]h9?4
if(responseCode>=400) bFpwq#PDW>
{ nsPM`dz/
processErrorCode(responseCode); eNNK;xXe#
return -2; //-2 represent access is error @RjLDj+)S
} V\_ &2',t
^l9S5 {
`7LdF,OdE
String sHeader; nm)F tX|A
fu`oDi
bvoR?D\-"
for(int i=1;;i++) B`vV[w?
{ B\Uj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mVxS[Gq
//Utility.log(in.readLine()); ~9{.!7KPc
sHeader=httpConnection.getHeaderFieldKey(i); V\ |b#?KL
if(sHeader!=null) (b(iL\B$D=
{ uW]n3)7<I
if(sHeader.equals("Content-Length")) ;3w W)gL1
{ uwbj`lpf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;y"DEFs,u
break; k,?k37%T]
} ZjzQv)gZ
} /+rHy7(\
else UZyo:*yB
break; ]!/1qF
} gw H6r3=y(
} PKP(:3|
catch(IOException e){e.printStackTrace ();} bNXT*HOZb3
catch(Exception e){e.printStackTrace ();} de"*<+
P^ a$?
%l>^q`p
Utility.log(nFileLength); @=$;^}JS|
oOuWgr]0
qLR)>$
return nFileLength; YcIk{_N3
} rn(T Z}
)msqt!Ev
k@[Bx>
//保存下载信息（文件指针位置） N(D_*% 96
private void write_nPos() |[*b[O 1W
{ 6`4=!ZfI
try{ $ED<:[3N
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5[0n'uH
output.writeInt(nStartPos.length); spJB6n(
for(int i=0;i<nStartPos.length;i++) P?>p+dM
{ Ef#%4ky
// output.writeLong(nPos); Z yIn>]{
output.writeLong(fileSplitterFetch.nStartPos); mX %;
output.writeLong(fileSplitterFetch.nEndPos); Mq$e5&/
} o0AREZ+I
output.close(); *r%=p/oQ}B
} !dZC-U~
catch(IOException e){e.printStackTrace ();} R#oXQaBJ
catch(Exception e){e.printStackTrace ();} 4B) prQ3
} !bQ5CB
gzeG5p
:Vv=p*~
//读取保存的下载信息（文件指针位置） CYz]tv}g:
private void read_nPos() ZMbv1*Vt
{ QH+Oi&xH
try{ {4 *ob@w*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ur_~yX]Mo
int nCount = input.readInt(); #\fApRL
nStartPos = new long[nCount]; q")}vN
nEndPos = new long[nCount]; gg933TLu(Q
for(int i=0;i<nStartPos.length;i++) gQ&FO~cr
{ syMB~g
nStartPos = input.readLong(); zg[ksny
nEndPos = input.readLong(); OD{Rh(Id
} [gU z9iU
input.close(); tlc&Wx
} {eS!cZJ
catch(IOException e){e.printStackTrace ();} L~~;i'J
catch(Exception e){e.printStackTrace ();} wF}/7b54
} kZfO`BVL
mim]nRd2v
|NL$? %I
private void processErrorCode(int nErrorCode) \ 3ha
{ iGM-#{5
System.err.println("Error Code : " + nErrorCode); evq*&.6\
} dKhDO`.s
*ZAue.
5X'[{'i,
//停止文件下载 _.zW[;84b
public void siteStop() {l![{
{ ^,@Rd\q
bStop = true; jrG@ +" }
for(int i=0;i<nStartPos.length;i++) %*zgN[/w
fileSplitterFetch.splitterStop(); FK0nQ{uB"
FSC74N/
@32JMS<
} nx84l7<
} 6*Rz}RQ
//负责部分文件的抓取 v:eVK!O
**FileSplitterFetch.java L=?Yc*vg
*/ 5)nm6sf
package NetFox; T-uI CMEf
NJwcb=*
MX]<tR`
import java.io.*; ^I@43Jy/
import java.net.*; S+7>Y? B!
nTyKZ(#u
u+kXJ
public class FileSplitterFetch extends Thread { =T!iM2
[*Wq6n
[PdatL2
String sURL; //File URL ["kk.*&
long nStartPos; //File Snippet Start Position 5l}v
long nEndPos; //File Snippet End Position 5e6f)[}
int nThreadID; //Thread's ID hVd% jU:
boolean bDownOver = false; //Downing is over gM '_1zs U
boolean bStop = false; //Stop identical }]'Z~5T
FileAccessI fileAccessI = null; //File Access interface ">j}!n 8J
^3^n|T7le
twq!@C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !SMIb(~[z
{ h:}oUr8
this.sURL = sURL; Y7{IF X
this.nStartPos = nStart; IR(qjm\V
this.nEndPos = nEnd; =bi:<%"
nThreadID = id; Dqs{n?@n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bODCC5yL
} :dc>\kUIv
)k&<D*5s
(3C::B=
public void run() _Y?p =;
{ Ys|tGU
while(nStartPos < nEndPos && !bStop) D37N*9}
{ BRLrD/8Le
gG!L#J?
YKlYo~fGN9
try{ V>>"nf,YO
URL url = new URL(sURL); !?,7Cu.5#6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zW+X5yK
httpConnection.setRequestProperty("User-Agent","NetFox"); `A_CLVE
String sProperty = "bytes="+nStartPos+"-"; b3N1SC:Wn
httpConnection.setRequestProperty("RANGE",sProperty); kj{z;5-dl
Utility.log(sProperty); J^m#984
g 4G&
@GNNi?EY
InputStream input = httpConnection.getInputStream(); ~oWCTj-
//logResponseHead(httpConnection); B4Ko,=pg
G>&Tap>
*](maF~%C
byte[] b = new byte[1024]; O~?H\2S
int nRead; M_lQ^7/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pnl7a$z
{ P:,'
nStartPos += fileAccessI.write(b,0,nRead); ^cs:S-s
//if(nThreadID == 1) % P .(L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *-'u(o
} FrT.<3
!W4A9Th
VRV*\*~$
Utility.log("Thread " + nThreadID + " is over!"); 094~ s
bDownOver = true; Aru=f~!
//nPos = fileAccessI.write (b,0,nRead); _IYd^c
} -}#=L@
catch(Exception e){e.printStackTrace ();} 6Lj=%&
} W}{RJWr
} }tJRBb
X67^@~l
=;Ap+}
//打印回应的头信息 ;n]GHqzY_
public void logResponseHead(HttpURLConnection con) ldk (zAB.
{ @-ps[b`z
for(int i=1;;i++) UVa:~c$U4
{ a@4 Zx
String header=con.getHeaderFieldKey(i); Se~<Vpo
if(header!=null) W}jel}:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Sp/t[\,'
Utility.log(header+" : "+con.getHeaderField(header)); {x_SnZz&
else 2MY-9(no
break; ^F\RM4|,
} b* (~8JxZ
} m03D+@F
[.:SV|AF#
K ?uHAm
public void splitterStop() ),cozN=NM
{ 9lXjB_wG>
bStop = true; 3lr9nBR
} '^mCLfo0}
r:N =?X`N
3mef;!q
} p6S{OUiG
(B+CI%= D
4f~ c#0?
/* 0ndk=V
**FileAccess.java Hreu3N
*//文件访问(定位，写) nUb0R~wr$G
package NetFox; <9f;\+zA
import java.io.*; -%f$$7
Lsu_f'p0
_EHz>DJ9
public class FileAccessI implements Serializable{ /Uxp5 b h
mv1g2f+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U)v){g3w)
RandomAccessFile oSavedFile; z3Id8G&>
long nPos; IhR;YM[K
??5y0I6+
~t=73fwB
public FileAccessI() throws IOException g}@W9'!
{ U~3uu&/r
this("",0); l7T@<V
} Q+<{2oVz
b6(LoN.
fI<|]c}P&J
public FileAccessI(String sName,long nPos) throws IOException 1Jm'9iy3
{ {^8->V
oSavedFile = new RandomAccessFile(sName,"rw"); K%jh6c8
this.nPos = nPos; OKo)p`BX
oSavedFile.seek(nPos); yV.E+~y
} U~CG(9
3bsuE^,.@
qQN|\u+co
public synchronized int write(byte[] b,int nStart,int nLen) <Pn]{N
{ wn1` 9
int n = -1; %>io$o
try{ ]S0tK
oSavedFile.write(b,nStart,nLen); !#[B#DZc(
n = nLen; Yq~$pVgf
} [[XbKg`"?
catch(IOException e) hnYL<<AA
{ Qr.SPNUFK
e.printStackTrace (); r+RFDg/
} B+VD53 V
kO3N.t@n
#jqcUno
return n; e'l@M$^
} uD=FTx
ztEM>xsk
5mqwNAv
} w. c]
wH0m^?a!3
j+eto'
/* Hd_W5R
**SiteInfoBean.java vk><S|[n
*/ ?9Hs,J
package NetFox; Ss~yy0
q?##S'
OF1fS\P<>
public class SiteInfoBean { QKHAN{hJ
(5/>arDn
Z1dLC'/b]
private String sSiteURL; //Site's URL 5>x?2rp
private String sFilePath; //Saved File's Path "3;b,<0
private String sFileName; //Saved File's Name 2kfX_RK
private int nSplitter; //Count of Splited Downloading File Vi*HG &DD
$S'~UbmYU
*Y]()#?Gr
public SiteInfoBean() u*6Y>_iA
{//nSplitter的缺省值为5 DG-XX.:z
//default value of nSplitter is 5 H&*KpOL
this("","","",5); 7=@3cw H
} s(0"r.
(#Ku`
I]iTD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ozOvpi:k3%
{ BM>'w,$KL
sSiteURL= sURL; vuoD~=z
sFilePath = sPath; FzzV%
sFileName = sName; U6xs'0
this.nSplitter = nSpiltter; =\FV_4)
@b3jO
)|N_Q}
} efrVF5,y?
1m4Xl%KS>
&UxI62[k
public String getSSiteURL() ;^DG P
{ f=--$o0U~
return sSiteURL; #V-0-n,`
} MO-7yp:K
),rd7GB>
Wz+7CRpeP
public void setSSiteURL(String value) _%gu<Ys
{ G?dxLRy.do
sSiteURL = value; lS96sjJp@
} Bm$(4
sNHxUI
HP(dhsd<c
public String getSFilePath() ] ^s,
{ :G[6c5j|V
return sFilePath; xe@11/F
} J.Fy0W@+k4
J e"~/+
)WH;G:$&"
public void setSFilePath(String value) $mu*iW\{
{ !m:rtPD'
sFilePath = value; 8nE}RD7bx
} vAcxca">S
)cV*cDL1j
&xLCq&j1
public String getSFileName() rWULv
{ 2Fc>6]:*
return sFileName; P}~nL
} ^-2|T__
C3:CuoE X
%DhM}f
public void setSFileName(String value) <! Z06
{ z)F<{]%
sFileName = value; I[w;soI
} vhd+A
\(`8ng]vs
7'zXf)!
public int getNSplitter() E+z"m|G
{ W,fXHYst
return nSplitter; %4,v2K
} ^_c6Op<F
!]C=5~BBI
?rxq//S2
public void setNSplitter(int nCount) f)19sjAJk
{ 5j~1%~,#
nSplitter = nCount; wfQ^3HL
} d;hv_h
} Xrr3KQaK&
*W-:]t3CR
EECuJ+T
/* svvl`|n%
**Utility.java 4A)@,t9+
*/ oM(8'{S=
package NetFox; KdXqW0nm
-gB9476-
F3e1&aK6{
public class Utility { {1;R&
2(AuhZ>
<7 xX/Z}M
public Utility() *!^l ZpF
{ BcxALRWE
|*(R$tX
r(KAG"5
} e+<'=_x {
+3[8EM#g
//线程睡眠 4o|<zn
public static void sleep(int nSecond) jSMxba]
{ CB^.N>'
try{ YL&)@h
Thread.sleep(nSecond); -dS@l'$
} _=_<cgy1u
catch(Exception e) %%sJ+)
{ l i) 5o
e.printStackTrace (); 3IG<Ot9
} 7yQw$zG,Iz
} } 89-U
<DZ$"t
//日志 "1Y'VpKm(~
public static void log(String sMsg) +~$pkxD"
{ SS6K7
System.err.println(sMsg); T^icoX=c4
} C`=YGyj=TL
w:+&i|H>
]j0/.pG
public static void log(int sMsg) xF6byTi
{ z/,&w_8,:
System.err.println(sMsg); N6HeZB":
} ~P BJ~j+G
} 8d7 NESYl
.: k6Kg
G|YNShK4=9
/* #z+?t
**TestMethod.java H[RX~Xk2E
*/ 8a3EVc
package NetFox; MML=J~1
>hY.F/[
1:!H`*DU&
public class TestMethod { u|cP&^S
s:3b.*t<
`|2g&Vn
public TestMethod() ~REfr}0
{ ///xx/weblogic60b2_win.exe %j@@J\G!
try{ xp}M5|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); IGOEqUw*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !/e*v>3u&
SiteFileFetch fileFetch = new SiteFileFetch(bean); @'<=EAXe
fileFetch.start(); l b;P&V
} x\oSD1t,
catch(Exception e){e.printStackTrace ();} EbG&[v
]$=#:uf
OT0IGsJ"'
} Iz[ohn!f
>a&IFi,j
iK=QP+^VN
public static void main(String[] args) ^YJ%^P
{ /0o#V-E)
new TestMethod(); @nAl*#M*D
} 2 w6iqLr?
} &->ngzg
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