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)); cX$ Pq
} # [c`]v
for(int i=0;i<nEndPos.length-1;i++) \hSOJ,{)U
{ ~2Jvb[IM
nEndPos = nStartPos[i+1]; ]$)J/L(p/]
} y:Ycn+X.
nEndPos[nEndPos.length-1] = nFileLength; jBexEdH
} bqmOfGM
} SooSOOAx[
Z/=x(I0
m09 Bds
//启动子线程 {b4+ Yc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 31b9pi}nf
for(int i=0;i<nStartPos.length;i++) Rg! [ic !
{ "g7`Ytln
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .@{W6 /I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uQ4WM
nStartPos,nEndPos,i); Z2d,J>-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $_,?SXM
fileSplitterFetch.start(); SdF*"]t
} R3;GMe@D#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7[)4k7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~Ein)5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U[5
nEndPos = " + nFileLength); Z IfhC'
// fileSplitterFetch[nPos.length-1].start(); DJSSc
D@T>z;
AtNu:U$
//等待子线程结束 oWGtKtDhH
//int count = 0; J[fjl6p
//是否结束while循环 Cg NfqT0
boolean breakWhile = false; B42.;4"T
%h;~@-$
Bfw]#"N`
while(!bStop) M|e Qds
{ *RKYdwnb
write_nPos(); (I~-mzu\
Utility.sleep(500); {4"!~W
breakWhile = true; )cc:Z7p
:4|W;Lkd!
[4,=%ez
for(int i=0;i<nStartPos.length;i++) y~_wr}.CS
{ 2T!pFcc
if(!fileSplitterFetch.bDownOver) &-#!]T-P:E
{ e=KA|"vxh
breakWhile = false; > t*+FcD
break; kDuN3
} ws:@Pe4AF
} |}paa
if(breakWhile) FVkb9(WW
break; f1F#U@U
$5aRu,
T 'pX)ZH
//count++; Kx.I'_Qk
//if(count>4) .L'>1H]B
// siteStop(); ks=jv:
} _1[5~Pnh
(C/2shr 8
ON~jt[
System.err.println("文件下载结束！"); fw@n[u{~
} '6*^s&H~
catch(Exception e){e.printStackTrace ();} 2<Lnfc<^k
} d*ch.((-
>x0"gh
1au1DvH
//获得文件长度 "\bbe@
public long getFileSize() MKSiOM
{ fvKb0cIx]
int nFileLength = -1; ]c,ttS_
try{ Afi;s.,
URL url = new URL(siteInfoBean.getSSiteURL()); [4'C4Zl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6?nAO
httpConnection.setRequestProperty("User-Agent","NetFox"); .XR`iXY
&VtTUy}
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int responseCode=httpConnection.getResponseCode(); zk8s?$
if(responseCode>=400) 1euL+zeh
{ gZ6]\l]J{
processErrorCode(responseCode); uev$5jlX
return -2; //-2 represent access is error /Y("Q#Ueq
} )`?Es8uW
co<-gy/mCR
47s<xQy
String sHeader; q6'3-@%
NqcmjHvy
WT$m*I
for(int i=1;;i++) Z+h^ ie"g
{ /7#KkMg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -.=q6N4
//Utility.log(in.readLine()); "2HSb5b"`
sHeader=httpConnection.getHeaderFieldKey(i); <H3njv
if(sHeader!=null) iLf:an*vH
{ Dpp3]en.
if(sHeader.equals("Content-Length")) w7NJ~iy
{ cRBdIDIc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]O2ku^yM
break; v2R41*z,
} %KL"f
} L|4kv
else !HyPe"`oL
break; 6@kKr
} qa 'YZE`
} ?eD,\G
catch(IOException e){e.printStackTrace ();} e R"XXF0u
catch(Exception e){e.printStackTrace ();} K2PV^Y
FT'_{e!M
6v7H?4
Utility.log(nFileLength); S'~Zlv3`
:Z|lGH =
|&vQ1o|}
return nFileLength; | _/D-m*
} [V'3/#Z
tpw0j CVu
iR j/Tm*T'
//保存下载信息（文件指针位置） a86m?)-c
private void write_nPos() /MHqt=jP6
{ csZIBi
try{ Am=D kkP%
output = new DataOutputStream(new FileOutputStream(tmpFile)); hM
output.writeInt(nStartPos.length); O8#}2
for(int i=0;i<nStartPos.length;i++) ZC+F*:$
{ idiJ|2T"G
// output.writeLong(nPos); <1#v}epD#
output.writeLong(fileSplitterFetch.nStartPos); 1.WdxMpW9
output.writeLong(fileSplitterFetch.nEndPos); ;!U`GN,tH
} z^=.05jB
output.close(); %Hdg,NH
} Oq~>P!=
catch(IOException e){e.printStackTrace ();} ;n?72&h
catch(Exception e){e.printStackTrace ();} W70J2
} #q.Q tDz
lN94 b3_W
BEM_y:#
//读取保存的下载信息（文件指针位置） OMG.64DX .
private void read_nPos() NQS@i'W=g
{ Pk444_"=
try{ !%b.k6%>w
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Yjxa=CD
int nCount = input.readInt(); Qd"{2>
nStartPos = new long[nCount]; m[&]#K6
nEndPos = new long[nCount]; ~J1;Z0}#
for(int i=0;i<nStartPos.length;i++) |0:&dw?*!
{ g0t$1cUR
nStartPos = input.readLong(); WtF
nEndPos = input.readLong(); gzqx{ ]
} )%p.v P'p
input.close(); UEmNT9V
} S%n5,vwE
catch(IOException e){e.printStackTrace ();} Y~]E6'Bz
catch(Exception e){e.printStackTrace ();} 3f9J!B`n
} ;8m_[gfw
hU=n>g>nx
I=)Hb?qT~
private void processErrorCode(int nErrorCode) 9u<4Q_I`
{ &$uQ$]&H
System.err.println("Error Code : " + nErrorCode); Qj(q)!Ku
} Q:?]:i/*
h-`Jd>u"
J \U}U'qP
//停止文件下载 Th,15H DA
public void siteStop() sl^i%xJ|l'
{ ^44AE5TO
bStop = true; @2Xw17[f35
for(int i=0;i<nStartPos.length;i++) >*rsRR
fileSplitterFetch.splitterStop(); vH_QSx;C#
5`,qKJ
dK|6p_
} ?,e7v.b
} C!xqp
//负责部分文件的抓取 vwQY_J8
**FileSplitterFetch.java un|+YqLf
*/ }{;m:Iia_
package NetFox; 6LZ(bP'd;
A,-UW+:
*njdqr2c~
import java.io.*; ?H8w/{J
import java.net.*; A `\2]t$z
[/uqH
$h1`-=\7
public class FileSplitterFetch extends Thread { 1zNH[
#W[/N|~wx
xC;b<~zN
String sURL; //File URL TS+itU62
long nStartPos; //File Snippet Start Position Q#NXJvI
long nEndPos; //File Snippet End Position K(RG:e~R0i
int nThreadID; //Thread's ID 9?<WRM3a>
boolean bDownOver = false; //Downing is over ;taTdzR_
boolean bStop = false; //Stop identical '6i"pJ0%
FileAccessI fileAccessI = null; //File Access interface 7z!|sPW](b
Y$SZqW0!/
hMz= \)Pl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _?Zg$7VJ
{ HJ[@;F|aU
this.sURL = sURL; Y6L_ _ RT
this.nStartPos = nStart; |&Gm.[IX;q
this.nEndPos = nEnd; KP" lz
nThreadID = id; a$!|)+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *BzqAi0
} em`z=JGG
)s^D}I(
|x*~PXb
public void run() ` MIZqHM @
{ 1HYrJb,d
while(nStartPos < nEndPos && !bStop) :f (UZmV$
{ b|| c^f
bmN'{09@
9`kxyh</
try{ ~i 'Ib_%h
URL url = new URL(sURL); ;w";s$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CDcZ6.f
httpConnection.setRequestProperty("User-Agent","NetFox"); c!l=09a~a+
String sProperty = "bytes="+nStartPos+"-"; *gMo(-tN
httpConnection.setRequestProperty("RANGE",sProperty); W0%cJ8~
Utility.log(sProperty); <PL94
SwHrHj
V'(yrz!
InputStream input = httpConnection.getInputStream(); d*80eB9P
//logResponseHead(httpConnection); /IS_-h7>XS
^g/
L+y}hb r
byte[] b = new byte[1024]; &P'cf|KI
int nRead; (VeX[*}I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b4%sOn,
{ vd`;(4i#X
nStartPos += fileAccessI.write(b,0,nRead); =\]5C
//if(nThreadID == 1) A*tG[)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %9ef[,WT
} KEF"`VTB@
KSsv~!3Yf
jA@jsv
Utility.log("Thread " + nThreadID + " is over!"); C}grY5:
bDownOver = true; ST'M<G%4E
//nPos = fileAccessI.write (b,0,nRead); `j+aAxJ=\
} Wt=QCutt
catch(Exception e){e.printStackTrace ();} `8^4,
} :%ms6j/B&V
} Sx{vZS3
yn=BO`sgW
"w3#2q&
//打印回应的头信息 6qfL-( G
public void logResponseHead(HttpURLConnection con) 1FC'DH!
{ Cx(|ZD^
for(int i=1;;i++) "%$jl0i_c
{ B3 fKb#T
String header=con.getHeaderFieldKey(i); Q;A1&UA2
if(header!=null) o%dKi]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n/$1&x1
Utility.log(header+" : "+con.getHeaderField(header)); 1#rcxUSi
else .bcoH
break; Y*0AS|r!
} +o+e*B7Eh
} NN(ZH73
t5 :4'%|
n.+%eYM<
public void splitterStop() c:QZ(8d]L
{ i*-[-hn-V
bStop = true; La&?0PA
} I =G3
>2Z0XEe
Mrpz(})
} hRK&
g}(yq:D
V`*N2ztSL
/* AAbI+L0m{
**FileAccess.java (`C#Tq
*//文件访问(定位，写) PuyJ:#a
package NetFox; ko-|hBNv
import java.io.*; Mf'T\^-!
i=Nq`BoQf
byALM
public class FileAccessI implements Serializable{ @ol}~&"
S0-f_,(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }4'5R
RandomAccessFile oSavedFile; 8%C7!l q
long nPos; S#km`N`
c8uFLM j
7 YS'Tf
public FileAccessI() throws IOException J+hiz3N
{ 04;E^,V
this("",0); 4yOYw*X
} -G\svwv@)
$;GH -+
Vl"20):
public FileAccessI(String sName,long nPos) throws IOException <%d/"XNg[D
{ |"}F cS y
oSavedFile = new RandomAccessFile(sName,"rw"); Vf28R,~m
this.nPos = nPos; MR")
oSavedFile.seek(nPos); rw:z|-r
} N{/):O
zVEG) Hr
4oxAC; L
public synchronized int write(byte[] b,int nStart,int nLen) ^,W;dM2
{ 5UWj#|t
int n = -1; -"Mq<XO&51
try{ ].AAHu5
oSavedFile.write(b,nStart,nLen); <Wd#HKIG>l
n = nLen; h2k"iO}
} kwI[BF
catch(IOException e) j!1 :+H_L
{ hA'i|;|ZYc
e.printStackTrace (); ^/'zU,
} 18*M
*dmBJi}
SX/E@vYb
return n; Os)jfKn2
} 2A>s a3\
SSr#MIS?
&A/k{(.XP
} 4F[4H\>'
7'IcgTWDZy
=()Vrk|uK
/* 7+(on
**SiteInfoBean.java |DUWB;
*/ uU$YN-
package NetFox; #)3luf3G
HB|R1<t;HB
7~zd % o
public class SiteInfoBean { |B{@noGX
dG8_3T}i
ww? AGd
private String sSiteURL; //Site's URL j\hI, mc
private String sFilePath; //Saved File's Path d76nyQKK
private String sFileName; //Saved File's Name a:v5(@8
private int nSplitter; //Count of Splited Downloading File LE@<)}Au^
;!~&-I0l
Z]~) ->=}
public SiteInfoBean() %XC3V7
{//nSplitter的缺省值为5 Jn:h;|9w
//default value of nSplitter is 5 S4ys)!V1V
this("","","",5); T]_]{%z
} "26=@Q^Y
R$|"eb5
yg@8&;bP`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o=zr]vv
{ }srmG|@:
sSiteURL= sURL; E|,RM;7
sFilePath = sPath; 6 2*p*t
sFileName = sName; >TQNrS^$J
this.nSplitter = nSpiltter; s~p(59
;_~9".'<d
3< 'bi}{
} 1m~-q4D)V
W9D~:>^YP
<5 )F9.$
public String getSSiteURL() $-i(xnU/nl
{ drwD3jx0xv
return sSiteURL; 6*&$ha}X
} F tS"vJ\
73p7]Uo
''Y'ZsQ;
public void setSSiteURL(String value) `R!%k]$
{ :L+%5Jq
sSiteURL = value; 9)?_[|2
} ~T^,5Tz1j
cM_!_8o
x DiGN Jc
public String getSFilePath() _LSp \{Z
{ 1w!O&kn
return sFilePath; jct|}U
} Ur9L8EdC
w/f?KN
,,c+R?D
public void setSFilePath(String value) ?E}9TQ
{ -UoTBvObAm
sFilePath = value; ]r\FC\n6e
} :Tcvj5
BUs={"Pa
PcQ\o>0")
public String getSFileName() Y@y"bjK \
{ /(u# D[
return sFileName; k>)Uyw$!
} ;XIDu6
IZ_?1%q>}
O))YJh"'_
public void setSFileName(String value) #&}j'oD|N
{ XW.k%H4@
sFileName = value; Nu;?})tF
} HcQ)XJPK
QJy1j~9x
2,6~;R
public int getNSplitter() 0N87G}Xu
{ mUNAA[0 L
return nSplitter; XI+GWNAmJ
} Y#t9DhzFWo
X#>:9
C %i{{Y&l
public void setNSplitter(int nCount) g#q7~#9
{ UOpSH{N
nSplitter = nCount; ^o87qr0g]
} 8#nAs\^
} #62*'.B4
Cq -URih
wq7h8Z}l
/* Alk+MwjR
**Utility.java `t"7[Zk
*/ f>iDqC4
package NetFox; cE^Ljk
L0)w~F ?m
%Jji<M]
public class Utility { Urz9S3#\
< V*/1{
`x`zv1U
public Utility() .lAPlJOO
{ ;efF]")
xpJ=yxO
m al?3*x/
} H]}mg='kI
mX%T"_^
//线程睡眠 pr[V*C/
public static void sleep(int nSecond) JM7FVB
{ ^WrL
try{ P(.XB`
Thread.sleep(nSecond); ;@*<M\O
} {%\@Z-9%q,
catch(Exception e) vScEQS$>
{ n/{ pQ&B
e.printStackTrace (); V aoqI
} ,A5}HRW%
} i#aKW'
o)GesgxFa5
//日志 x];i? 4
public static void log(String sMsg) 6:q,JB@i
{ YwS/O N
System.err.println(sMsg); &Oc `|r*
} fRb
h$XoR0
`-.6;T}2U
public static void log(int sMsg) D_?dy4\
{ 82 dmlPwJC
System.err.println(sMsg); :NL[NbQYt
} #uV J
} ;9Qxq]
|~@yXc5a
au]W*;x
/* $:yIe.F
**TestMethod.java vJ{F)0 K
*/ F1S0C>N?5
package NetFox; v 8EI
Nt;1&dwUb
(f2r4Io|}
public class TestMethod { _F(Np\%_
^E_chx-e}
$o.;}
public TestMethod() T[I7.8g
{ ///xx/weblogic60b2_win.exe bXeJk]#y
try{ 86eaX+F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5|7<ZL3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k(M"k!M
SiteFileFetch fileFetch = new SiteFileFetch(bean); O)ose?Z
fileFetch.start(); AV4fN@BX
} XSCcumde!
catch(Exception e){e.printStackTrace ();} @ M4m!;rM
M~h.MPI
A)gSOC{3F)
} /'zXb_R,$
"sIww
wwet90_g
public static void main(String[] args) gi>W&6
{ 0e07pF/!
new TestMethod(); (5A8#7a
} F-F1^$]k
} H]W'mm
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