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)); l; */M.B
} n/Or~@pHD
for(int i=0;i<nEndPos.length-1;i++) Scf.4~H 0
{ &,F elB0*
nEndPos = nStartPos[i+1]; PaA6Z":
} aTi0bQW{
nEndPos[nEndPos.length-1] = nFileLength; `yy%<&
} ~y`Pwj
} %jpH:-8'2
P%ye$SASd
yM W'-\
//启动子线程 La@\q[U{@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Un~]Q?w
for(int i=0;i<nStartPos.length;i++) z)r8?9u
{ "ngSilH?D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [+yGDMLs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,CN#co
nStartPos,nEndPos,i); x!Y(Y=i>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wbo{JQ
fileSplitterFetch.start(); tP -5
} % 1OC#&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E`U&Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6 bYC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Al)lWD}j2g
nEndPos = " + nFileLength); }7otuO(pRo
// fileSplitterFetch[nPos.length-1].start(); F%9e@{
lrq>TJEcx
9$n+-GSK
//等待子线程结束 7O]J^H+7
//int count = 0; Q=dw 6
//是否结束while循环 oA5<[&~<
boolean breakWhile = false; A3m{jbh
q|?`Gsr
LNWqgIq
while(!bStop) {H/8#y4qp&
{ )j$b9ZBk
write_nPos(); p|xs|O6{
Utility.sleep(500); wV7@D[8
breakWhile = true; >B@i E
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]:[)KZ~
for(int i=0;i<nStartPos.length;i++) 9<+;hH8J_r
{ vQ?MM&6
if(!fileSplitterFetch.bDownOver) )*"T
{ +d|:s
breakWhile = false; 8') .ohD
break; 5)h+(u C3
} \H},ouU
} W*1d X"S
if(breakWhile) #i'C
break; nNkyOaK*4
@&/s~3
(jD'+ "?
//count++; cg>!<T*
//if(count>4) k8!hvJ)?
// siteStop(); UUt~W
} ay!6T`U`
<L[T'ZE+
yBUZVqqDa
System.err.println("文件下载结束！"); r@N39O*Wq
} Q"x`+?!
catch(Exception e){e.printStackTrace ();} L{+&z7M
} &ryl$!!3H
)*q7pO\cty
&<\4q
//获得文件长度 IBn'iE[>
public long getFileSize() B<vvsp\X
{ !Qj)tS#Az
int nFileLength = -1; &;SwLDF"1
try{ m70`{-O
URL url = new URL(siteInfoBean.getSSiteURL()); s{x*~M$vt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cij]&$;Q
httpConnection.setRequestProperty("User-Agent","NetFox"); ?uNTUU,
4i ~eTb
xg*\j)_}
int responseCode=httpConnection.getResponseCode(); ~z-?rW
if(responseCode>=400) v Ie=wf~D`
{ __oY:d(~
processErrorCode(responseCode); -N /8Ho
return -2; //-2 represent access is error ?0 KiR?
} E7d~#
2ID*U d*
$9LGdKZ_D
String sHeader; B;Q`vKY
f}evw K[S
F:[Nw#gj/
for(int i=1;;i++) ^VM"!O;h{
{ o>/uW8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :8\*)"^E
//Utility.log(in.readLine()); 1[fkXO{
sHeader=httpConnection.getHeaderFieldKey(i); -+j9X;h:
if(sHeader!=null) DjevX7Q
{ /r::68_KQP
if(sHeader.equals("Content-Length")) <=5,(a5g
{ : 9djMsd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CWobvR)e
break; Fyi?,,
} PU]7c2.y
} 5p#o1I
else xr7-[)3Q$
break; IL8'{<lM
} i"2J5LLv
} tWCv]*
catch(IOException e){e.printStackTrace ();} )zk?yY6
catch(Exception e){e.printStackTrace ();} z<3}TD
BJ:E,P`_
2ZTyo7P
Utility.log(nFileLength); #Of<1
Q+y-*1
x`j$9XN5
return nFileLength; V)WIfRs
} 6I5[^fv45G
)Ta]6
^-csi
//保存下载信息（文件指针位置） /:*R -VdF
private void write_nPos() W_e-7=6
{ 'aSZ!R
try{ @vQ;>4i.
output = new DataOutputStream(new FileOutputStream(tmpFile)); z$8e6*
output.writeInt(nStartPos.length); ZPxOds1m
for(int i=0;i<nStartPos.length;i++) :3E8`q~c1
{ ;ZE<6;#3IP
// output.writeLong(nPos); ^G7n#
output.writeLong(fileSplitterFetch.nStartPos); RpaA)R,
output.writeLong(fileSplitterFetch.nEndPos); $@ T6g
} qw Kh,[]
output.close(); //'xR8Z
} ATXx? b8h
catch(IOException e){e.printStackTrace ();} gs`27Gih
catch(Exception e){e.printStackTrace ();} btB(n<G2#
} .H[Lo>
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>gS5[`xRE
//读取保存的下载信息（文件指针位置） =5s~$C
private void read_nPos() LNyL>VHkK
{ Js^r]=\F'
try{ @Z=y'yc'y.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2\iD;Z#gM
int nCount = input.readInt(); v0H>iKh7
nStartPos = new long[nCount]; ^c[CyZ:a
nEndPos = new long[nCount]; nfd?@34"A2
for(int i=0;i<nStartPos.length;i++) ;|2;kvf"w
{ ,pGCgOG#}c
nStartPos = input.readLong(); u6bB5(s`&
nEndPos = input.readLong(); s6eq?1l3
} CpP$HrQ
input.close(); B 3,ig9
} 4o)\DB?!
catch(IOException e){e.printStackTrace ();} ?G%, k LJJ
catch(Exception e){e.printStackTrace ();} ]mJAKycE%
} 8en#PH }
no\}aTx
d@q t%r3;
private void processErrorCode(int nErrorCode) !~$YD*"S
{ Yf2+@E
System.err.println("Error Code : " + nErrorCode); Jj^<:t5{rN
} 4{;8 ]/.a
H$qdU!c
DT7-v4Zd
//停止文件下载 T$8$9D_u
public void siteStop() mG8
{ qzU2H
bStop = true; 37M[9m|D*
for(int i=0;i<nStartPos.length;i++) M@LaD 5
fileSplitterFetch.splitterStop(); KSpC%_LC
iw]BQjK
;6&=]I
} Lh9>8@ jf
} IG3K Pmu
//负责部分文件的抓取 y8(?:#ZC
**FileSplitterFetch.java ,ex(pmZ;
*/ PB3!;
package NetFox; VkP:%-*#v
Xm:gD6;9
Iy1XnS*
import java.io.*; s%TO(vT
import java.net.*; @*`UOgP7
|{|r?3
;(iUY/ h[h
public class FileSplitterFetch extends Thread { ^$s~qQQ}B
Iz$W3#hi
J'Mgj$T $
String sURL; //File URL B6!<@*BI
long nStartPos; //File Snippet Start Position IkXKt8`YVA
long nEndPos; //File Snippet End Position |EEz>ci
int nThreadID; //Thread's ID S bqM=I+
boolean bDownOver = false; //Downing is over '>WuukC
boolean bStop = false; //Stop identical YvP"W/5
FileAccessI fileAccessI = null; //File Access interface o!_; H}pq
.Mft+,"
`\u),$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [{!j9E?(
{ z1KC$~{O
this.sURL = sURL; u{lDof>
this.nStartPos = nStart; /*p?UW<*4
this.nEndPos = nEnd; 6Bq2?;5
nThreadID = id; Qc =lf$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,DUQto
} A =Az[
@.]K6qC
", Rw%_
public void run() MKhL^c-
{ 0-MasI&b
while(nStartPos < nEndPos && !bStop) +mQC:B7>
{ g}og@UY7#
IOES3
g#<?OFl
try{ DBh/V#* D
URL url = new URL(sURL); &T/9yW[L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -0J<R;cVs
httpConnection.setRequestProperty("User-Agent","NetFox"); AiHDoV+-
String sProperty = "bytes="+nStartPos+"-"; LGgx.Z
httpConnection.setRequestProperty("RANGE",sProperty); Q_|S^hxQ
Utility.log(sProperty); uM!r|X)8
Va[dZeoy
<Phr`/
InputStream input = httpConnection.getInputStream(); {^O/MMB\\%
//logResponseHead(httpConnection); SVEA
}PD(kk6fX
w0%ex#lkm
byte[] b = new byte[1024]; ]~x/8%e76
int nRead; :bF2b..XOu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %|6Q7'@p
{ 3'@jRK
nStartPos += fileAccessI.write(b,0,nRead); >U Ich
//if(nThreadID == 1) g:6}zHK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]X;*\-
} *z:lq2"G
LFM5W&?
(IQ L`3f%
Utility.log("Thread " + nThreadID + " is over!"); XK9*,WA9r
bDownOver = true; R\=\6("
//nPos = fileAccessI.write (b,0,nRead); R#^pNJN
} RuEnr7gi
catch(Exception e){e.printStackTrace ();} *wZV*)}
} -EIMh^
} ?@BaBU:o`F
7}7C0mV3
BCDf9]X
//打印回应的头信息 ]qG5Ne_
public void logResponseHead(HttpURLConnection con) n~cm?"
{ <yaw9k+P
for(int i=1;;i++) IG@&l0ARL
{ iP\&fZY_
String header=con.getHeaderFieldKey(i); aZ0iwMK
if(header!=null) N0KRND
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?U[nYp}"v
Utility.log(header+" : "+con.getHeaderField(header)); $W]guG
else 48*pKbbM4
break; QL!+.y%
} ;xC~{O
} HQj4h]O#
JWjp<{Q;1
+uXnFf d^
public void splitterStop() "JGig!9
{ +GtGyp
bStop = true; \B+SzW
} `fh_8%m]*
gM[ J'DMW
g5N<B+?!i
} (w
,colGth54
dllf~:b
/* f;dU72]q+
**FileAccess.java H LGy"P
*//文件访问(定位，写) p%_ :(
package NetFox; D??/=`|8
import java.io.*; dp W%LXM_
UC$+&&rO
T1[ZrY'0
public class FileAccessI implements Serializable{ "<R 2oo)^
|VF"Cjw?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X,CFY
RandomAccessFile oSavedFile; LMj'?SuH
long nPos; nECf2>Yp v
N2Hb19/k
\`# 0,pLr
public FileAccessI() throws IOException HBGA lZ
{ Upen/1bA
this("",0); m3e49 bP
} U MIZ:*j
T<GD!j(
7OHw/-j\
public FileAccessI(String sName,long nPos) throws IOException nOzTHg8
{ |H@p^.;
oSavedFile = new RandomAccessFile(sName,"rw"); glIIJ5d|,
this.nPos = nPos; IcA~f@
oSavedFile.seek(nPos); eZ$1|Sj]j
} {-qTU6
k= 1+mG
Jtk(yp{Zz
public synchronized int write(byte[] b,int nStart,int nLen) [p<[83' ]
{ ~]+ jn
int n = -1; e:occT
try{ &cE,9o%FZ
oSavedFile.write(b,nStart,nLen); a}hM}U!
n = nLen; {627*6,
} z9w.=[Io
catch(IOException e) xK'IsMo[
{ 2a-hf|b1
e.printStackTrace (); =LA@E&,j
} #E)]7!_XG
3&:fS|L~c
qRLypm
return n; 6%1o<{(%f
} T+!kRigN~P
sRnMBW.
X.|0E87
} $4,6&dwg
#0H[RU?
>Sah\u`
/* 4+bsG6i
**SiteInfoBean.java Okc*)crw
*/ 8 \Oiv$r
package NetFox; 4tWI)}+ak
H4jqF~
4/_|Qy
public class SiteInfoBean { $Bb/GXn{\
(DAJ(r~
5)6%D
private String sSiteURL; //Site's URL +06j+I
private String sFilePath; //Saved File's Path lNAHn<ht
private String sFileName; //Saved File's Name WQ`T'k#ESW
private int nSplitter; //Count of Splited Downloading File i(rY'o2 BN
net9KX4\
px@\b]/
public SiteInfoBean() ^Yz05\
{//nSplitter的缺省值为5 ZZ7U^#RT
//default value of nSplitter is 5 d5hE!=
this("","","",5); s~G{-)*
} OK(d&
4y.[tk5
"<#:\6aym
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Df^S77&c!
{ P#PQ4uK \
sSiteURL= sURL; >j3N-;o@?
sFilePath = sPath; Bs}>#I
sFileName = sName; Q8i6kf!
this.nSplitter = nSpiltter; RGmpkQEp
dW68lVWq_
]+P&Y:
} W9"I++~f
*6tN o-)^
C"<@EMU9
public String getSSiteURL() t`B']Ac;T
{ ?f&I"\y
return sSiteURL; :~Y$\Ww(~
} R3A^VE;qP
XT"c7]X
Gy%e%'
public void setSSiteURL(String value) 1O4"MeF
{ 0 HmRl
sSiteURL = value; Q2Rj0E`
} )/'s& D
K-3 _4As
HxaUVg0
public String getSFilePath() z^.0eP8\j
{ y rk#)@/m
return sFilePath; flqTx)xE
} 5@ug1F&
wn&2-m*a
X$f%Ss
public void setSFilePath(String value) .EO1{2=
{ L8ke*O$
sFilePath = value; q0wVV
} (6nw8vQ
HenJlo
~@lNBF
public String getSFileName() F04Etf 2k
{ R8l9i2
return sFileName; xJCpWU3wM
} )w-?|2-w5
CCV~nf
Rd)QVEk>SD
public void setSFileName(String value) UZ#2*PH2E
{ >YLm]7v}
sFileName = value; v&n&i?
} g%trGW3{-
@#apOoVW>
Sls> OIc
public int getNSplitter() /Ny&;Y
{ +Sfv.6~v
return nSplitter; e=2D^G#qE
} F*f)Dv$p
]_s]Q_+E
sXu]k#I^"
public void setNSplitter(int nCount) lS^0*(Y
{ @zbXG_J
nSplitter = nCount; s><co]
} AM>:AtY
} JFZ p^{
P*>V6SK>b
ioggD
/* !_@%/I6
**Utility.java D_Y;N3E/rS
*/ hlRE\YO&8R
package NetFox; Y{KJk'xN5W
-MjRFa
KVuv%?
public class Utility { 0NxaQ`\
]NCOi?Odx
art{PV4-
public Utility() /03>|Juo
{ m| Z)h{&
(]:G"W8f
F}Au'D&n_
} @lwqkJ
&+v&Dd&
//线程睡眠 tz,FK;8
public static void sleep(int nSecond) ?D_zAh?pW
{ DjIs"5Iei
try{ x>^S..K}L%
Thread.sleep(nSecond); Gsb]e
} {8' 5
catch(Exception e) ' vwBG=9C
{ B !XT:.+
e.printStackTrace (); U&6f}=vC
} :|a[6Uwl\V
} ydt1ED0Q-
QUt!fF@t
//日志 157X0&EX
public static void log(String sMsg) ZU`"^FQ3A
{ W>~V?%F&'
System.err.println(sMsg); X\;y;pmRH
} P.o W#Je
.eE5pyw+C
$)U RY~;i
public static void log(int sMsg) gnQd#`
{ STI8[e7{
System.err.println(sMsg); >2a~hW|,
} Sz =z TPnO
} n#*cVB81
f =Nm2(e
MYjCxy-;A
/* O%Mh g\#B
**TestMethod.java n3(HA
*/ fc91D]c
package NetFox; 6vDgMfw
.MKxHM7
Fq8Z:;C8
public class TestMethod { [(C lvGx
KLX>QR@
}5K\l
public TestMethod() iY="M_kQ_
{ ///xx/weblogic60b2_win.exe {S?.bT%&
try{ TtzB[F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]?^mb n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s SDBl~g
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'G&w[8mqY
fileFetch.start(); `!i>fo~
} &:rf80`z.
catch(Exception e){e.printStackTrace ();} Ae"B]Cxb_X
]]+"`t,-
O?@AnkOhn
} s^cHR1^
[8ih-k
o.,hCg)X
public static void main(String[] args) 8O]$)E
{ |q?A8@\u
new TestMethod(); ^W^%PJD|
} [|vdr.
} b<%6aRC\
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