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)); /N({"G'
} ySB0"bl
for(int i=0;i<nEndPos.length-1;i++) c^O&A\+;
{ @eZBwFe
nEndPos = nStartPos[i+1]; qX`Hi9ja
} }VRl L>HAC
nEndPos[nEndPos.length-1] = nFileLength; oB%_yy+
} &qK:LHhj
} JQ;.+5 N<K
F\hVunPVx
6yBd9=3K
//启动子线程 Z^}[CQ&Am
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {/(.Bpld
for(int i=0;i<nStartPos.length;i++) (t\U5-w
{ 'Hzc"<2Y\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $hHV Ie]+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *Ojl@N
nStartPos,nEndPos,i); L+VQtp&"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?E_;[(Mcr
fileSplitterFetch.start(); nbB*d@"
} , O/IY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :5['V#(o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u;]xAr1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `a:3S@n(}
nEndPos = " + nFileLength); k$ T
// fileSplitterFetch[nPos.length-1].start(); ;Xa N
AAs&P+;
ByuBZ!m
//等待子线程结束 &XdTY +
//int count = 0; Q-!gO
//是否结束while循环 hkyO_ns
boolean breakWhile = false; H] g=( %ok
0{uaSR
/D1Lh_,2
while(!bStop) $_,-ESI
{ O_ZYm{T[7
write_nPos(); :8j7}'
Utility.sleep(500); !Vg=l[
breakWhile = true; 3z, Ci$[
K,JK9)T
\EU^`o+
for(int i=0;i<nStartPos.length;i++) Ssuz%*
{ /M::x+/T
if(!fileSplitterFetch.bDownOver) <5mv8'{L
{ w3"L5;oH
breakWhile = false; `Oi#`lC\
break; AC'_#nPL#
} ^a`3)WBv8
} 1og+(m`BL
if(breakWhile) G&Dl($
break; |`Noj+T47I
(hdu+^Qj=
t$~'$kM)<
//count++; /:Gy .
//if(count>4) rjiHP;-t1
// siteStop(); jDqG9]
} 8!cHRtqK
`'^o45
;x2o|#`b
System.err.println("文件下载结束！"); Z\Ur F0
} T&MhSJf#
catch(Exception e){e.printStackTrace ();} me{u~9&
} r#2Fk&Z9
Z~QLjv&$/r
|dbKK\ X9
//获得文件长度 tK .1 *
public long getFileSize() 4p-"1c$
{ /gl8w-6
int nFileLength = -1; uDXV@;6<
try{ Z]R#F0"U
URL url = new URL(siteInfoBean.getSSiteURL()); qB,0(I1-!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0IdA!.|
httpConnection.setRequestProperty("User-Agent","NetFox"); H8[A*uYL
oSmETk\
jwAYlnQ^EM
int responseCode=httpConnection.getResponseCode(); D*[Jrq,
if(responseCode>=400) [`qdpzUp&
{ s2NBYDi$?
processErrorCode(responseCode); c?EvrtND
return -2; //-2 represent access is error GM'yOJo
} YI;iG[T,&
G"E_4YkJ
>;hAw!|#
String sHeader; !&hqj$>-}
U-4F
mB"I(>q*M
for(int i=1;;i++) {ri={p]l
{ !OY}`a(z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tE{M
//Utility.log(in.readLine()); e2NK7
sHeader=httpConnection.getHeaderFieldKey(i); d6'G 7'9
if(sHeader!=null) pvUV5^B(M
{ %b<W]HwA
if(sHeader.equals("Content-Length")) +x}9a~QG#
{ dd<l;4(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q)Nw$dW<
break; L;$>SLl,
} ?#xm6oe#aH
} t1o 6;rK
else Z:7eroZP
break; B+U:=591
} wB[f%mHs
} d[p2?]
catch(IOException e){e.printStackTrace ();} <>9!oOa
catch(Exception e){e.printStackTrace ();} 1u7D:h>#
OVDuF&0
oV0 45G
Utility.log(nFileLength); 65qqs|&w;[
_Iav2=0Wi
} v:YSG
return nFileLength; -ycYQ~R
} mc8Q2eQat}
th[v"qD9G
ty.$H24
//保存下载信息（文件指针位置） k:run2K
private void write_nPos() ;z.niX.fx
{ ~Ay)kv;
try{ HrvyI)4{
output = new DataOutputStream(new FileOutputStream(tmpFile)); WIf.;B)L
output.writeInt(nStartPos.length); [UI>SN
for(int i=0;i<nStartPos.length;i++) <6Gs0\JB
{ >h;]rMD!|
// output.writeLong(nPos); :tU^
output.writeLong(fileSplitterFetch.nStartPos); X:g5;NT
output.writeLong(fileSplitterFetch.nEndPos); >d p/
} reh{jMC
output.close(); 0t^FM<7G
} dGBjV #bNT
catch(IOException e){e.printStackTrace ();} e~zgH\`
catch(Exception e){e.printStackTrace ();} rY45.,qWs
} mLZ1u\7W
gtu<#h(
4/`;(*]Fv
//读取保存的下载信息（文件指针位置） Z>g>OPu
private void read_nPos() N=<`|I
{ CL1*pL
try{ G]f|?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8CZfz!2
int nCount = input.readInt(); O;<wDh)Yt
nStartPos = new long[nCount]; M['O`^
nEndPos = new long[nCount]; +`k30-<P
for(int i=0;i<nStartPos.length;i++) 3PU_STSix
{ /"?DOsJ.
nStartPos = input.readLong(); `hj,rF+4
nEndPos = input.readLong(); yj&GJuNb~
} cZ:jht
input.close(); >jAFt_
} +:;ddV
catch(IOException e){e.printStackTrace ();} bp:`m>4<
catch(Exception e){e.printStackTrace ();} K$h\<_V
} y'!OA+ob
H)D|lt5xy
%T]^,y$n
private void processErrorCode(int nErrorCode) K9k!P8Rd
{ Q*>)W{H&)
System.err.println("Error Code : " + nErrorCode); p lnH
} ]A=\P,D
&/WM:]^?0)
5N|LT8P}Z
//停止文件下载 'l.tV7
public void siteStop() `w:kY9
{ zx}+Q B0
bStop = true; 3?*dv14
for(int i=0;i<nStartPos.length;i++) 2 3PRb<q
fileSplitterFetch.splitterStop(); baII!ks
hYkkr&
)C8^'*!
} wg?}c ;
} cr!W5+r
//负责部分文件的抓取 Jh EC
**FileSplitterFetch.java XY'8oU`]{
*/ R<&Euph
package NetFox; +ausm!~6
'2r
<x^$Fu
import java.io.*; Z?'CS|ud
import java.net.*; H:~p5t
9u(pn`e 3
;pW8a?
public class FileSplitterFetch extends Thread { M[mYG _{J
Qt+D ,X
larv6ncV
String sURL; //File URL Dz~0(
long nStartPos; //File Snippet Start Position -pYmM d,
long nEndPos; //File Snippet End Position t`K9K"|k
int nThreadID; //Thread's ID f1_;da
boolean bDownOver = false; //Downing is over pRobx
boolean bStop = false; //Stop identical L K#A
FileAccessI fileAccessI = null; //File Access interface N# }w1]
_k2R^/9Ct%
QAV6{QShj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dP8qP_77A~
{ kT@ITA22
this.sURL = sURL; dA hcA.
this.nStartPos = nStart; ;\0|1Eem`
this.nEndPos = nEnd; lz0-5z+\
nThreadID = id; , lR(5ZI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6LDZ|K@
} a20w.6F
':4<[Vk
>j=ZB3yZ
public void run() L}*o8l`
{ _VT{2`|})
while(nStartPos < nEndPos && !bStop) oDA'$]UL
{ V|'@D#\
"mJo<i}
lubsLI
try{ 7#E/Q~]'6
URL url = new URL(sURL); Z{^!z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s9wzN6re
httpConnection.setRequestProperty("User-Agent","NetFox"); n>v1<^
String sProperty = "bytes="+nStartPos+"-"; *LB-V%{|'
httpConnection.setRequestProperty("RANGE",sProperty); /+92DV
Utility.log(sProperty); e#;43=/Ia
"rn
G!I++M"
InputStream input = httpConnection.getInputStream(); {A0F/#M]
//logResponseHead(httpConnection); 6)^*DJy
fxcE1=a
FvT4?7-
byte[] b = new byte[1024]; NRx 7S9W
int nRead; W8g13oAu"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }'P|A
{ SSF:PTeG>
nStartPos += fileAccessI.write(b,0,nRead); i`sZP#h
//if(nThreadID == 1) h2zSOY{su
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :5~Dca_iU4
} 1/9*c *w
<9pI~\@w
IE\RP!
Utility.log("Thread " + nThreadID + " is over!"); @H?OHpJ"`
bDownOver = true; K`N$nOw
//nPos = fileAccessI.write (b,0,nRead); l\{Qnb(
} *,X)tZ6VX
catch(Exception e){e.printStackTrace ();} }SSg>.48w
} ~},H+A!?
} 6n2RTH
R9A:"sJ
2@a'n@-
//打印回应的头信息 KJT N"hF
public void logResponseHead(HttpURLConnection con) DIGw4g4Kt
{ \2/X$x<?X
for(int i=1;;i++) _ooHB>sH
{ t[!,puZc#
String header=con.getHeaderFieldKey(i); M#^q <K %
if(header!=null) D/=05E%[81
//responseHeaders.put(header,httpConnection.getHeaderField(header)); = cxO@Fu
Utility.log(header+" : "+con.getHeaderField(header)); ]#M"|iTR
else e2=}qE7
break; jF;<9-m&
} $HQ~I?r{Hf
} c_qox
3/vtx9D
\/1~5mQ+
public void splitterStop() 2tK~]0x
{ l^R:W#*+U
bStop = true; &;ddnxFI
} -J63'bb7oi
'n7|fjX?Y
BPkMw'a:
} s&ox%L4
&G%AQpDW5
i}LQ}35@
/* qE2<vjRg
**FileAccess.java &k)+]r
*//文件访问(定位，写) *=@8t^fa86
package NetFox; l atm_\
import java.io.*; $Z&6
%t_'rv
qsp3G7\'=
public class FileAccessI implements Serializable{ vhOh3
E~q3o*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ds] .Ae
RandomAccessFile oSavedFile; Eo$l-Hl5=
long nPos; T+XcEI6w
7x`$A
eW.qMx#:od
public FileAccessI() throws IOException z&!o1uq
{ JL_(%._J
this("",0); `GqF/?i
} XzV>q~I3|E
hRuiuGC
^'Lp<YJs6
public FileAccessI(String sName,long nPos) throws IOException 6p;Pf9 f
{ ;0_T\{H"nR
oSavedFile = new RandomAccessFile(sName,"rw"); %pg)*>P h
this.nPos = nPos; Z=-#{{bv
oSavedFile.seek(nPos); w#9.U7@.
} f|~'(~Sr
=X'EDw
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public synchronized int write(byte[] b,int nStart,int nLen) Onqapm0
{ n\Is}Czl
int n = -1; mu0L_u(P
try{ k7:ISjJ
oSavedFile.write(b,nStart,nLen); ,?U(PEO\f
n = nLen; +q2\3REzx
} &z3_N
catch(IOException e) (Ajhf}zJ
{ 2pHR$GZ2
e.printStackTrace (); LL:N/1ysG
} 2O(k@M5E?
UV%o&tv|<
9i#,V@
return n; T\zn&6
} ~xam ;]2
)`k+Oyvi<
>.39OQ#
} \zcSfNE
"j`T'%EV
fc:87ZR{K
/* ;N!n06S3
**SiteInfoBean.java rfdA?X{Q0
*/ ~mH'8K|l
package NetFox; 7 HL Uk3
sk5=$My
([JFX@
public class SiteInfoBean { 3mE8tTA$R
s!09cS
78T;b7!-C
private String sSiteURL; //Site's URL #@Tm5z
private String sFilePath; //Saved File's Path o}36bi{
private String sFileName; //Saved File's Name z4.|N
private int nSplitter; //Count of Splited Downloading File 8oHIXnK
E]{0lG`l
ViOXmK"
public SiteInfoBean() oMn'{+(w
{//nSplitter的缺省值为5 8f?o?c|
//default value of nSplitter is 5 ~Gg19x.#uW
this("","","",5); `h'Ab63
} %,N-M]Jf
"}uu-5]3
T?n[1%K
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P'5Lu
{ DS|x*w'I
sSiteURL= sURL; 7}=MVp] )S
sFilePath = sPath; /$8& r
sFileName = sName; UQ e1rf
this.nSplitter = nSpiltter; ,^iT,MgNNf
50S*_4R
H6#SP~V
} Hb!A\;>
Q Na*Y@i
R8% u9o
public String getSSiteURL() y(Pv1=e
{ k3 '5Ei
return sSiteURL; \>/AF<2"
} _}`y3"CD7
{yBd{x<>/
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public void setSSiteURL(String value) E&vCzQ
{ cJ,`71xop,
sSiteURL = value; "g!/^A!!
} 9zehwl]~
kx0w?A8-
/{ 8.Jcx$
public String getSFilePath() |[bQJ<v6
{ =:RNpi,
return sFilePath; :d~&Dt<c
} x6yO2Yo
,l)AYu!q4F
k"`^vV[{F
public void setSFilePath(String value) Z!?T&:
{ j~ qm5}
sFilePath = value; G#^6H]`[J:
} G|$n,X1O(
dfeN_0`-
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public String getSFileName() 1N8YD .3
{ BGT`) WP
return sFileName; SkXx:@
} i;+<5_
i\L7z)u
M w+4atO4[
public void setSFileName(String value) G>^ _&(c@2
{ 1UH_"Q03
sFileName = value; R<>uCF0
} YH[HJ#:7r
wlX K2D
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public int getNSplitter() 28,HZaXhc
{ 6;\Tps;A
return nSplitter; hcD.-(-;)
} iEBxBsz_
fVBu?<=d
6[1lK8o
public void setNSplitter(int nCount) Q mz3GH@wg
{ -F-,Gcos
nSplitter = nCount; k:E+]5
} Bk4|ik}
} |fWR[\NU
QtqE&j
2Y9@[
/* gG6BEsGa,
**Utility.java BG@[m
*/ -Ly A
package NetFox; xHwcP21
A `=.F
{$-\)K
public class Utility { _k5-Wd5Ypw
}D#[yE,=\
1\Vp[^#Vx
public Utility() !%yd'"6Dl
{ ez*O'U
cU=/X{&Om
(@u"
} v%2Jm!i+
o7 X5{
//线程睡眠 u!VY6y7p
public static void sleep(int nSecond) UXV>#U?
{ fxX4 !r
try{ kv/mqKVr
Thread.sleep(nSecond); A v%'#1w<"
} h|&qWv
catch(Exception e) so\8.(7n
{ xHdv?69,
e.printStackTrace (); !p"Ijz5
} [kg*BaG:
} [U?a %$G>
lF1ieg"i M
//日志 0f|nI8,z
public static void log(String sMsg) V\><6v
{ sr,8Qd0M
System.err.println(sMsg); h7W<$\P
} B6a
8:(e~? f6
* d[sja+
public static void log(int sMsg) 8Ow0A
{ 0Fm,F&12
System.err.println(sMsg); 3P2L phW
} g JMv
} 2(sq*!tX
cn!Y7LVr
k7Z1Y!n7
/* T$;N8x[
**TestMethod.java ~w9ZSSb4
*/ 'gwh:8Xc
package NetFox; |G]M"3^
s;-%Dfn
\?.Tq24
public class TestMethod { /WKp\r(Hp
~,.}@XlgT.
VN9C@ ;'$
public TestMethod() /SZg34%
{ ///xx/weblogic60b2_win.exe 'xY@I`x
try{ s\dF7/b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;X3bgA']
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CK+_T}+-
SiteFileFetch fileFetch = new SiteFileFetch(bean); m`lsUN,
fileFetch.start(); Z}'"c9oB
} BAS3&fA
catch(Exception e){e.printStackTrace ();} i^'Uod0d.
j8Csnm0
#/Qe7:l
} %@Ty,d:;=
(Q09$
P*;zDQy
public static void main(String[] args) Xz, sL
{ +b]+5!
new TestMethod(); <+c6CM$#}V
} 7&z`N^dz{
} "ewB4F[
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