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)); M Qlx&.>
} db0]D\
for(int i=0;i<nEndPos.length-1;i++) ])H[>.?K
{ XPsRa[08WK
nEndPos = nStartPos[i+1]; .|z8WF*
} j55;E E!
nEndPos[nEndPos.length-1] = nFileLength; qCku q
} GR>kxYM%q
} IH$ZPux
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Eu1t*>ZL
//启动子线程 <X~P62<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \O(~:KN
for(int i=0;i<nStartPos.length;i++) .<kbYo:MV
{ PQA}_o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6PdLJ#LS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xfADks2w
nStartPos,nEndPos,i); yHjuT+/wM,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \S[I:fw#&
fileSplitterFetch.start(); t @vb3
} P&}J(;Lbl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mB<*we
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r`5svY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I*hzlE
nEndPos = " + nFileLength); VFLW@
// fileSplitterFetch[nPos.length-1].start(); \ICc?8oL
y;xY74Nq
8\B]!
//等待子线程结束 Gx/kel[Y}
//int count = 0; mq6TwM
//是否结束while循环 y)GH=@b
boolean breakWhile = false; y,cz;2
s?~lMm' !
]x:>!y
while(!bStop) A#KfG1K>
{ \zM3{{mV/
write_nPos(); K4K]oT
Utility.sleep(500); W2T6JFv
breakWhile = true; c=#V*<
:oO ?A
L wP
for(int i=0;i<nStartPos.length;i++) ['jr+gIfQ
{ x_$`#m{hL5
if(!fileSplitterFetch.bDownOver) Zj5B}[,l\
{ pUD(5v*0R
breakWhile = false; f S-PM3
break; E)z=85;_p
} TAp8x
} gOLN7K-)
if(breakWhile) jU0E=;1
break; uN+]q qCf
"^NsbA+
Q]hl+C$d"/
//count++; g`r4f%O
//if(count>4) w:c9Z=KX
// siteStop(); i.Z iLDs\7
} (L'|n*Cr
Qs\*r@6?
$~)YI/b
System.err.println("文件下载结束！"); W@FSQ8b>$m
} B<\HK:%{
catch(Exception e){e.printStackTrace ();} ^\C Fke=
} eI3ZV^_Ps
SI, t:=D
rBUWzpE"
//获得文件长度 z=yE- I{
public long getFileSize() O 8XHaVLg3
{ *~0U4kw+
int nFileLength = -1; l?)!^}Qc
try{ @RXkj-,eC#
URL url = new URL(siteInfoBean.getSSiteURL()); J^y?nE(j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ge1b_?L_
httpConnection.setRequestProperty("User-Agent","NetFox"); uZe"M(3r$
d3"QCl
E4, J"T|@
int responseCode=httpConnection.getResponseCode(); M2pFXU?]
if(responseCode>=400) &M{;[O{
{ L%;[tu(*
processErrorCode(responseCode); Fxv5kho
return -2; //-2 represent access is error W[<ZI>mf
} :JIJ!Xn)
0)rayzv
bYBEh n
String sHeader; H*HL:o-[
SZ1yy["
bCqTubbx!t
for(int i=1;;i++) L30$
{ xO&qo8*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -CLBf'a
//Utility.log(in.readLine()); c<,R,DR
sHeader=httpConnection.getHeaderFieldKey(i); u~7fK
if(sHeader!=null) E<sd\~~A:
{ (\UpJlW
if(sHeader.equals("Content-Length")) Y49&EQ
{ lc\{47LwZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aM+Am,n`@
break; qPBOt;N
} )kDB*(?
} Z rv:uEl
else ,ygUy]
break; V5'(op/
} otX/sg.B*
} |u]IOw&1
catch(IOException e){e.printStackTrace ();} xVk5%
catch(Exception e){e.printStackTrace ();} Ey=ymf.}
<$??Z;6
7n,=`0{r
Utility.log(nFileLength); XK&G`cJ[
-2'1KAk-W
+{0v@6<(02
return nFileLength; >&ENrvaJ
} 0f#xyS 3
{gh<SZsE
+kN,OK~
//保存下载信息（文件指针位置） AuT:snCzR
private void write_nPos() ]>B4
{ 8([ MR
try{ +;-ZU
output = new DataOutputStream(new FileOutputStream(tmpFile)); zx5#eMD
output.writeInt(nStartPos.length); WPAT\Al&AE
for(int i=0;i<nStartPos.length;i++) \/64Xv3L0
{ vi28u xc
// output.writeLong(nPos); ZUkM8M$c
output.writeLong(fileSplitterFetch.nStartPos); sI.p( -KQ
output.writeLong(fileSplitterFetch.nEndPos); 0O[le*3b
} c h}wXn
output.close(); -lrcb/)Gz
} #\ uB!;Q
catch(IOException e){e.printStackTrace ();} 4n"6<cO5q
catch(Exception e){e.printStackTrace ();} 6-z(34&N
} aWPf3Q
(D:-p:q.
Gt)ij?~
//读取保存的下载信息（文件指针位置） &(lQgi+^!
private void read_nPos() F^Bk @
{ <HtGp6q
try{ @]!9;?so
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @lWYc`>}
int nCount = input.readInt(); =3ovaP
nStartPos = new long[nCount]; 9khMG$
nEndPos = new long[nCount]; H+Aidsn
for(int i=0;i<nStartPos.length;i++) 3"juj'
{ 5|cRHM#
nStartPos = input.readLong(); 'E&tEbY
nEndPos = input.readLong(); Zrp-Hv27,,
} xS>vmnW
input.close(); tW a'[2L
} \~g,;>%7Y
catch(IOException e){e.printStackTrace ();} S*gm[ZLQ
catch(Exception e){e.printStackTrace ();} 9c%CCZ
} Wm}gnNwA
\E[6wB>uN%
,Js-'vX
private void processErrorCode(int nErrorCode) % m"Qg<
{ ,,!P-kK$
System.err.println("Error Code : " + nErrorCode); +u&[ j/
} F-$!e?,H
s/.P/g%tA>
wqi0%Cu*
//停止文件下载 cg o
public void siteStop() &>B"/z
{ 8Ihl}aguW
bStop = true; J.'%=q(Sb
for(int i=0;i<nStartPos.length;i++) ANNVE},
fileSplitterFetch.splitterStop(); fs?H
)ki Gk}2
Eh)VT{vp
} l4dG=x}M]
} %`QgG
//负责部分文件的抓取 Q6wa-Y,
**FileSplitterFetch.java zvVo-{6
*/ t0GJ$])
package NetFox; hNhEA $X5
{ 0-on"o
Ctn 4q'Q
import java.io.*; z:$ibk4#h
import java.net.*; hO&_VCk
TEh.?
$8xb|S[
public class FileSplitterFetch extends Thread { p_(En4QSH
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gO)":!_n W
String sURL; //File URL zhm0J-g
long nStartPos; //File Snippet Start Position CJER&"em7
long nEndPos; //File Snippet End Position a+cDH
int nThreadID; //Thread's ID $dXx@6fP
boolean bDownOver = false; //Downing is over *c [^/
boolean bStop = false; //Stop identical J8i,[,KcE
FileAccessI fileAccessI = null; //File Access interface ~\8(+qIv%f
d,?Tq
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException awwSgy
{ Gw\..O
this.sURL = sURL; ZOMYo]
this.nStartPos = nStart; NPrLM5
this.nEndPos = nEnd; EEnl'
nThreadID = id; /aMOZ=,q}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 aWlIq(dU
} EwX{i}j_V
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public void run() } ck<R
{ {?5iK1|}K
while(nStartPos < nEndPos && !bStop) *m^\&
{ vy*-"=J
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#CaPj:>[
try{ PkI+z_
URL url = new URL(sURL); v&'#Gg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q[C?1Kc.z
httpConnection.setRequestProperty("User-Agent","NetFox"); 9O:l0 l
String sProperty = "bytes="+nStartPos+"-"; #XA`n@2Uoo
httpConnection.setRequestProperty("RANGE",sProperty); g27'il
Utility.log(sProperty); 9aY8`B
{x.0Yh7
nvT@'y+
InputStream input = httpConnection.getInputStream(); 5.oIyC^Ik
//logResponseHead(httpConnection); 1kKfFpN
|5tZ*$nGa
&=BzsBh
byte[] b = new byte[1024]; ?q9]H5\
int nRead; [#q]B=JB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BhzDV
{ <y] 67:"<v
nStartPos += fileAccessI.write(b,0,nRead); QcW8A ,\q
//if(nThreadID == 1) Wz s=BNm9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); flo$[]`.7
} nAEyL+6U
M@{#yEP
z__?kY
Utility.log("Thread " + nThreadID + " is over!"); |Z<\kx
bDownOver = true; n)98NSVDbT
//nPos = fileAccessI.write (b,0,nRead); ,`Y$}"M4
} "mf$E|
catch(Exception e){e.printStackTrace ();} jt on\9
} ESIP+
} U`i5B;k}-
+q'1P}e
xNf}f 9l
//打印回应的头信息 NFZ(*v1U
public void logResponseHead(HttpURLConnection con) j*G: 8Lg
{ {]<c6*gQ
for(int i=1;;i++) \agZD+
{ T5."3i
String header=con.getHeaderFieldKey(i); 1.F&gP)9
if(header!=null) rBNVI;JZW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8ROKfPj;z
Utility.log(header+" : "+con.getHeaderField(header)); p8_^6wfg
else ]*\MIz{56'
break; tLTavE[@
} &Y=0 0
} 14B',]`
r!?ga
(Z(S?`')
public void splitterStop() $M 8&&M
{ >ep<W<b
bStop = true; 31a,i2Q4
} \X:e9~
oT):#,s
() _RLA
} dA~:L`A|X
iVI&
r |C.K
/* {fzX2qMZ]
**FileAccess.java bGH#s {'5
*//文件访问(定位，写) j)mU`b_
package NetFox; A~bSB n: '
import java.io.*; 5]N0p,f
|(3y09
q>.7VN[ vE
public class FileAccessI implements Serializable{ M\C9^DX{
Nrr}) g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q()o|V
RandomAccessFile oSavedFile; T,pr&1]Lw
long nPos; /GIGE##1F
THp_ dTD
rMDvnF
public FileAccessI() throws IOException rF-SvSj}
{ *#mmk1`
this("",0); 9efDM
} {5E8eQ
})/P[^
SH{@yS[c!
public FileAccessI(String sName,long nPos) throws IOException xz8e1M
{ ltNCti{Q
oSavedFile = new RandomAccessFile(sName,"rw"); o+E~iCu5
this.nPos = nPos; G&g;ROgY
oSavedFile.seek(nPos); 0+FPAqX
} .n]"vpWm[
V#7,vas
,=u;1
public synchronized int write(byte[] b,int nStart,int nLen) sm/aL^4
{ ?% 24M\
int n = -1; @*YF!LdU{M
try{ !Ld5Y$
oSavedFile.write(b,nStart,nLen); u /F!8#
n = nLen; 8!{*!|Xd
} ?s^qWA
catch(IOException e) )j36Y =r3
{ ,<rC,4-F<
e.printStackTrace (); h+Co:pr
} */;7Uv7
?.46X^
XjGS.&'I
return n; >&PM'k
} jq,M1
&jF'2D^_
*-nO,K>y`
} \)~d,M}kK
el9P@r0
mAW.p=;
/* u5oM;#{@-
**SiteInfoBean.java |2j,
*/ = j1Jl^[
package NetFox; }HoCfiE=X
e'3V4iU]
="voJgvw
public class SiteInfoBean { Tz @=N]D
|H?t+Dyn)q
_Vr- bpAf
private String sSiteURL; //Site's URL v76Gwu$d
private String sFilePath; //Saved File's Path W@T\i2r$z
private String sFileName; //Saved File's Name {cXr!N^K
private int nSplitter; //Count of Splited Downloading File VHD+NY/
WywS1viD
Dp([r
public SiteInfoBean() %F 2h C x
{//nSplitter的缺省值为5 }(nT(9|
//default value of nSplitter is 5 h3?>jE=H
this("","","",5); fN&\8SPE
} /+Z*)q+SbT
&u>dKf)5
3a?-UT!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -l= 4{^pK
{ w|9 >4
sSiteURL= sURL; "2cOSPpQL
sFilePath = sPath; FH,]'
sFileName = sName; $tmdE)"&
this.nSplitter = nSpiltter; Y2r}W3F=
Q@W/~~N
cRT'?w`}
} -5<[oBL;
|R}=HsYey
>w S'z]T9
public String getSSiteURL() e(0OZ_w
{ Ehx9-*]
return sSiteURL; Tv=lr6t8
} S^rf^%
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h=#w< @
public void setSSiteURL(String value) `B)@
{ Z`S#> o
sSiteURL = value; w2DC5ei'
} b#_RZ
2ioHhcYdJU
A=N$5ZJ
public String getSFilePath() +RooU?Aq
{ 7:jLZ!mgi
return sFilePath; 7f>=-sv
} C"I jr=w
t(z]4y
2&1mI>:F
public void setSFilePath(String value) 2aYBcPFQh#
{ Scrj%h%[
sFilePath = value; xo[o^go
} .t "VsY|
_?~%+Oz/
W"NI^OX
public String getSFileName() K[z)ts-
{ *Al@|5
return sFileName; K<>kT4
} [}L~zn6>?a
HRf;bKZ
FNQ<k[#K'~
public void setSFileName(String value) ,2FK$:M\
{ MAek856
sFileName = value; o"VKAP
} d[a(uWEl
J,Sa7jv[
)WqolB
public int getNSplitter() W==~9
{ 2R/|/>T v
return nSplitter; F1Z'tjj+
} LF7-??'
*tXyd<_Hd
&6sF wK
public void setNSplitter(int nCount) *9'3 `^l
{ @:>"VP<(
nSplitter = nCount; @]Cg5QW>T
} cN,*QN
} U=n7RPw
<,} h8;Fr
xC`!uPk/pL
/* ,L<JG
**Utility.java tsb[=W!Ar8
*/ 2*Qv6 :qK
package NetFox; $+4DpqJ
N~)-\T:ap
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public class Utility { Y1PR?c Q
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"Rj PTRe:
public Utility() s=8H<'l
{ v) n-
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x%mRDm~-
} (y9KO56.V&
dFz"wvu` o
//线程睡眠 9?l a5
public static void sleep(int nSecond) dtTn]}J
{ h:4(Gm;
try{ }*:3]
Thread.sleep(nSecond); j`_S%E%X
} +CSpL2@
catch(Exception e) f}-'67*Y
{ <i~xJi%1#
e.printStackTrace (); SXL3>-Z E
} {$frR "K
} 4"P9z}y=i
o 4F'z
//日志 MPB[~#:
public static void log(String sMsg) 7b"fpB
{ | eBwcC#^
System.err.println(sMsg); `J.,dqGb
} Sdq}?-&Sa
[Sm<X
t'44X
public static void log(int sMsg) <6Q^o[L
{ w"R<8e=
System.err.println(sMsg); %-n)L
} Xh"9Bcjf
} o#qdgZ
<F9-$_m
x{R440"
/* "| nXR8t.r
**TestMethod.java Wdd}y`lS
*/ DGvuo 8
package NetFox; 2 }xePX9?
qk& F>6<9*
{hS!IOM
public class TestMethod { Rpn<"LIoB:
x1gS^9MqCB
lSX1|,B7:]
public TestMethod() L.;b(bFe
{ ///xx/weblogic60b2_win.exe "tyRnUP
try{ 45yP {+/-Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K,S4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i%i~qTN
SiteFileFetch fileFetch = new SiteFileFetch(bean); opa/+V3E4
fileFetch.start(); yy3rh(ea
} I!/32* s1t
catch(Exception e){e.printStackTrace ();} zhJeTctRz
PD&e6;rj;
HoQb.Z
} YIe1AF}
}c,b]!:
4%0s p
public static void main(String[] args) mE~WE+lw9
{ !U`4
new TestMethod(); h"[B zX
} cK$yr)7
} /?81Ypt
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