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)); 9cw4tqTm
} ?SsRN jeL
for(int i=0;i<nEndPos.length-1;i++) S*DBY~pZy
{ x/jN&;"/
nEndPos = nStartPos[i+1]; Do[ F+Y
} zvQ^f@lq2
nEndPos[nEndPos.length-1] = nFileLength; Sj]T{3mi
} D.oS8'
} R(7X}*@X
!~$YD*"S
3Oig/KZ
//启动子线程 Yf2+@E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |Z^c#R
for(int i=0;i<nStartPos.length;i++) )lngef /D_
{ WSpg(\Cs
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gp|7{}Q{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'k(~XA}X:
nStartPos,nEndPos,i); Q+%m+ /Zq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aBA#\eV
fileSplitterFetch.start(); GO:1 Z?^
} J?,!1V=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,[K)E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n9-q5X^e>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2YP"nj#
nEndPos = " + nFileLength); o"+&^
// fileSplitterFetch[nPos.length-1].start(); WY.\<$7
OD@@O9
{/|8g(
//等待子线程结束 nD?M;XN
//int count = 0; DHujpZXQ
//是否结束while循环 X-2S*L'
boolean breakWhile = false; /xm} ?t0U
k @/SeE
Wp9 2sm+
while(!bStop) .5Z@5g`
{ 3vGaT4TDx
write_nPos(); z&HN>7
Utility.sleep(500); Zn*CJNB
breakWhile = true; $nd-[xV
~PS2[5yo
TXvt0&-
for(int i=0;i<nStartPos.length;i++) Z=/L6Zb
{ |~"A:gf
if(!fileSplitterFetch.bDownOver) .1?i'8TF
{ MFdFZkpiV
breakWhile = false; eJ)KE5%n#
break; Bc"}nSjH
} TAXkfj
} |9i/)LRXe
if(breakWhile) Z_4H2HseL
break; LXEu^F~{u#
0 c'2rx
s"Pk-Dv
//count++; i\R\bv[9
//if(count>4) Ai_|)
// siteStop(); q!h*3mNm
} 8!fAv$g0
hu*>B
%IH|zSr)EM
System.err.println("文件下载结束！"); ", Rw%_
} sT"tS>
catch(Exception e){e.printStackTrace ();} 0-MasI&b
} +mQC:B7>
g}og@UY7#
IOES3
//获得文件长度 wbF1>{/"
public long getFileSize() DBh/V#* D
{ &T/9yW[L
int nFileLength = -1; I8oKa$RF
try{ AiHDoV+-
URL url = new URL(siteInfoBean.getSSiteURL()); '*{Rn7B5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1X_!%Z
httpConnection.setRequestProperty("User-Agent","NetFox"); \w\47/k{
Va[dZeoy
`&Of82*w
int responseCode=httpConnection.getResponseCode(); aKU8" 5
if(responseCode>=400) c68$pgG
{ RknSWuFKt
processErrorCode(responseCode); Gqz)='
return -2; //-2 represent access is error ^A$XXH'
} AeQ&V d|
zSvHvs
](6vG$\
String sHeader; o6yZ@R
O09g b[
`[u>NEb
for(int i=1;;i++) Q_h+r!b
{ Kz2^f@5=F
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bzL;)H4Eo
//Utility.log(in.readLine()); ,?N_67
sHeader=httpConnection.getHeaderFieldKey(i); V`&*%xgGR
if(sHeader!=null) l{SPV8[i
{ dE!=a|Pl
if(sHeader.equals("Content-Length")) k)t8J\
{ -+2xdLa63
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d1_*!LW$
break; JRs[%w`kD
} uC ;PP=z
} q@yabuN@,j
else _I"<?sh3
break; <y/AEY1
} T1W9@9,s
} vh.tk^&
catch(IOException e){e.printStackTrace ();} "YU~QOGx@
catch(Exception e){e.printStackTrace ();} ^9~%=k=
@9P9U`ZP
Y`p&*O
Utility.log(nFileLength); ]Lft^,7
y/*Tvb #TJ
=@/^1.`
return nFileLength; [*E.G~IS`
} wbKBwI5w
!x /Z"
bH]!~[
//保存下载信息（文件指针位置） @MH]s [{o\
private void write_nPos() Z 2jMBe
{ -.3k vL
try{ exU=!3Ji
output = new DataOutputStream(new FileOutputStream(tmpFile)); otVdx&%]
output.writeInt(nStartPos.length); 8pt<)Rs}
for(int i=0;i<nStartPos.length;i++) FQRcZpv;
{ nk.Eq[08
// output.writeLong(nPos); f3B8,>
output.writeLong(fileSplitterFetch.nStartPos); 4T\/wyq0
output.writeLong(fileSplitterFetch.nEndPos); ^u&Khc~ y
} T}x%=4<E
output.close(); k"-#ox!
} eC:Q)%$%l
catch(IOException e){e.printStackTrace ();} iz5wUyeg
catch(Exception e){e.printStackTrace ();} W%QtJB1)
} ~TIZumGB
TmH13N]
hds4_
//读取保存的下载信息（文件指针位置） eTHh
private void read_nPos() 6u3(G j@
{ >x0lSL0y
try{ epyYo&x}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m)w-mc
int nCount = input.readInt(); -\v8i.w0
nStartPos = new long[nCount]; 3`8xh9O
nEndPos = new long[nCount]; $ !=:ES
for(int i=0;i<nStartPos.length;i++) [<$d@}O
{ 8uW:_t]q
nStartPos = input.readLong(); PX/0 jv
nEndPos = input.readLong(); ?2>v5p
} .Sw'Bo!Ee
input.close(); =xP{f<`
} .Q@'Ob`
catch(IOException e){e.printStackTrace ();} V2skr_1
catch(Exception e){e.printStackTrace ();} [)c|oh%
} 84cH|j`w
4u7>NQUDu
RL8wSK
private void processErrorCode(int nErrorCode) {-qTU6
{ k= 1+mG
System.err.println("Error Code : " + nErrorCode); Jtk(yp{Zz
} [p<[83' ]
~]+ jn
e:occT
//停止文件下载 &cE,9o%FZ
public void siteStop() a}hM}U!
{ izo $0
bStop = true; z9w.=[Io
for(int i=0;i<nStartPos.length;i++) xK'IsMo[
fileSplitterFetch.splitterStop(); 2a-hf|b1
=LA@E&,j
#E)]7!_XG
} 3&:fS|L~c
} qRLypm
//负责部分文件的抓取 6%1o<{(%f
**FileSplitterFetch.java T+!kRigN~P
*/ ?!-im*~w
package NetFox; wB"Gw` D
5(Oc"0''H
#0H[RU?
import java.io.*; >Sah\u`
import java.net.*; 4+bsG6i
~cwwB{
G"wQ(6J@
public class FileSplitterFetch extends Thread { +2O_LPV$,
4N: ;Mo&B
6>J#M
String sURL; //File URL MqH~L?~}|
long nStartPos; //File Snippet Start Position z6(Q 3@iO
long nEndPos; //File Snippet End Position Ba~Iy2\x
int nThreadID; //Thread's ID F tjm@:X
boolean bDownOver = false; //Downing is over j]SkBZgik
boolean bStop = false; //Stop identical ?yK\L-ad
FileAccessI fileAccessI = null; //File Access interface #1R %7*$i
gvYs<,:
B[50{;X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2_v>8B
{ :"]ei@
this.sURL = sURL; $S{j}74[
this.nStartPos = nStart; :LG%8Z{R
this.nEndPos = nEnd; A4h/oMis
nThreadID = id; g.s oNqt=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rg.if"o
} H)tDfk sq\
F{tSfKy2
~G:7*:[b
public void run() cw{[B%vw
{ "-%H</
while(nStartPos < nEndPos && !bStop) v^'~-^s
{ iSHl_/I<
nrBitu,
!f6
try{ :DJ@HY
URL url = new URL(sURL); [*t EHW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v(~m!8!TI
httpConnection.setRequestProperty("User-Agent","NetFox"); *E'K{?-K
String sProperty = "bytes="+nStartPos+"-"; -^DB?j+
httpConnection.setRequestProperty("RANGE",sProperty); UtN>6$u
Utility.log(sProperty); jfamuu7
ow"Xv
;0'v`ob'.?
InputStream input = httpConnection.getInputStream(); FO$Tn+\6
//logResponseHead(httpConnection); UepBXt3)
OFv} jT
566Qikw2
byte[] b = new byte[1024]; lfP|+=^B
int nRead; ^cm^JyS)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ri ~2t3gg
{ IIkJ"Qg.
nStartPos += fileAccessI.write(b,0,nRead); y rk#)@/m
//if(nThreadID == 1) flqTx)xE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5@ug1F&
} wn&2-m*a
X$f%Ss
.EO1{2=
Utility.log("Thread " + nThreadID + " is over!"); L8ke*O$
bDownOver = true; q0wVV
//nPos = fileAccessI.write (b,0,nRead); (6nw8vQ
} HenJlo
catch(Exception e){e.printStackTrace ();} ~@lNBF
} F04Etf 2k
} at!?"u
:F&WlU$L
)w-?|2-w5
//打印回应的头信息 CCV~nf
public void logResponseHead(HttpURLConnection con) Rd)QVEk>SD
{ tUQ)q
for(int i=1;;i++) d/1XL[&
{ s9iM hCu|
String header=con.getHeaderFieldKey(i); \BL9}5y
if(header!=null) @#apOoVW>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); SCij5il%
Utility.log(header+" : "+con.getHeaderField(header)); VzesqVx
else 5oS\uX|
break; o6 /?WR9
} VM[8w`
} @d\F; o<
"|if<hx+
3nO|A: t
public void splitterStop() n>WS@b/o
{ XJ;/kR
bStop = true; h.*|4;
} (agdgy:#
Xc!w y9m
3>+;G4
} 2olim1
9[`6f8S_$
:9}*p@
/* |wDCIHzQ
**FileAccess.java n[@Ur2&)
*//文件访问(定位，写) 9=|5-?^
package NetFox; !r<7]nwV
import java.io.*; lK-I[i!
]G:xTv8
K_i2%t3
public class FileAccessI implements Serializable{ jKzjTn9{E
s>5 Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >EY0-B
RandomAccessFile oSavedFile; o&]qjFo\m
long nPos; k;sUDmrO
S~T[*Z/m
X6)LpMm
public FileAccessI() throws IOException SpgVsz
{ cnR>)9sX
this("",0); 5 F-Q&
} U:Y?2$#
T1E{NgK
L" o6)N
public FileAccessI(String sName,long nPos) throws IOException nV,a|V5Xm
{ cQ`,:t#[
oSavedFile = new RandomAccessFile(sName,"rw"); ?U |lZ~o
this.nPos = nPos; +~-|( y
oSavedFile.seek(nPos); DcOLK\
} hXCDlCO
;bX{7j
.qZ<ROZ
public synchronized int write(byte[] b,int nStart,int nLen) b|NEU-oy
{ Y3[@(
int n = -1; + '`RJ,K+[
try{ 5GKz@as8
oSavedFile.write(b,nStart,nLen); R:Lu)d>=
n = nLen; 9cLKb
} M0|z^2
catch(IOException e) 6R25Xfm_|
{ ?g'l/xuRe
e.printStackTrace (); 2,+H;Ypi!
} 7P
<t8})
GB#7w82
return n; d^7<l_u~ !
} !Ej<J&e
Rh=h{O
{?8rvAjY
} ?^dyQhb
9:1ZL_yf
S7bSR?~L[
/* 8:f(PN
**SiteInfoBean.java v[m>;Ubg&
*/ 4h|vd.t
package NetFox; [Y[|:_+5
fA8 ,wy|>
?g 3sv5\u
public class SiteInfoBean { COap*
'G&w[8mqY
%n^]1R#
private String sSiteURL; //Site's URL #r\uh\Cy
private String sFilePath; //Saved File's Path =#W6+=YN8
private String sFileName; //Saved File's Name v"j7},P@
private int nSplitter; //Count of Splited Downloading File L(.5:&Y=`
k20tn ew
|K]tJi4fz
public SiteInfoBean() y0xte&
{//nSplitter的缺省值为5 >">-4L17m
//default value of nSplitter is 5 139_\=5|U/
this("","","",5); Y9ru~&/o$
} hGsYu)
ujaaO6oZ7
o!Y7y1$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MD+Q_
{ +7=3[K
sSiteURL= sURL; B9]KC i
sFilePath = sPath; B{44|aq1|
sFileName = sName; [ACa<U/
this.nSplitter = nSpiltter; um/iK}O
WkT4&|POJ
;e+ErN`a.~
} 4XRVluD%W.
a$ Z06j
L9T|*?||
public String getSSiteURL() 0L'h5i>H)
{ O[!]/qP+.
return sSiteURL; 4g|}]K1s
} FbF P
(f7R~le
&T{+B:*v
public void setSSiteURL(String value) WawOap
{ Ls( &.
sSiteURL = value; Hd :2
} d%iMjY`~[g
$. Ih-
"lB[IB)
public String getSFilePath() n;[d{bU
{ [S4<bh!
return sFilePath; XLB7 E
} )Zox;}WK+
k/>k&^?
Z<`QDBN"4
public void setSFilePath(String value) 3qP! (*
{ nBR4j?':i
sFilePath = value; n*uT
} 3>ytpXUEGx
Dc U$sf*
fnB[b[
public String getSFileName() :M3Fq@w=
{ F.4xi+S_
return sFileName; C-&\qAo?<:
} i!(u4wTFF
Tv!zqx#E
P9BShC5
public void setSFileName(String value) RK< uAiU
{ NSZ9M%7
sFileName = value; W;Ct[Y8m
} $/K<hT_
?g}G#j
,VI2dNst\
public int getNSplitter() 6YNd;,it>p
{ L\aG.\
return nSplitter; voiWf?X
} 5y0N }}
wZ0RI{)s'
X3@Uih}|
public void setNSplitter(int nCount) ;O+= 6>W
{ nH_M#
nSplitter = nCount; )1N~-VuT
} Dr)B0]KG
} ',P$m&z
OQ&l/|{O0?
@cukoLAn
/* ]V^ >aUlj
**Utility.java HQX.oW
*/ Z/RSZ-
package NetFox; K|]/BjB/
s+DOr$\
508v:?^'
public class Utility { <- L}N '
#A\@)wJ
{\hjKP
public Utility() f3^Anaa]l
{ *PM#ngLX}r
}]<0!q &xB
4 Fl>XM
} ]Q$Sei5
}p5_JXBV
//线程睡眠 Kl_(4kQE_
public static void sleep(int nSecond) 3$G &~A{
{ $t0o*i{
try{ f\xmv|8
Thread.sleep(nSecond); wDR/Vr"f
} 5If.[j{
catch(Exception e) 4K5
{ q#=HBSyM
e.printStackTrace (); 5/8=Do](
} Y \Gx|
} R"W5R-
|yS %
//日志 2DUY4Ti
public static void log(String sMsg) HA$Xg j
{ %:t! u&:q
System.err.println(sMsg); j<'ftKk
} fJOwE g|
b+1!qNuCW#
1%ENgb:8
public static void log(int sMsg) L+N\B@ 0-
{ M0yv=g
System.err.println(sMsg); !#d5hjoX
} &+ "<ia(
} `R;i1/
LI*=T
\#4mPk_"
/* _iu~vU)r
**TestMethod.java F42<9)I
*/ CFC15/yU
package NetFox; 1*" 7q9x
F/x2}'
G9|2 KUG
public class TestMethod { 'i',M+0>jC
C#-HWoSi
d~ +(g!
public TestMethod() _B>'07D0
{ ///xx/weblogic60b2_win.exe ^"<x4e9+j
try{ 0<7sM#sI!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yIhPB8QL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s]]lB018O\
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;4l8Qg 7
fileFetch.start(); 9 ,:#Q<UM
} k@ <dru
catch(Exception e){e.printStackTrace ();} -L+kt_>
,OWk[0/
UB/"&I uo
} h4jo<yp\
v4<W57oH
A 0v=7 ]
public static void main(String[] args) 9u^M{6
{ )X?oBNsj
new TestMethod(); Mgr?D
} yX4Vv{g
} 58XZ]Mc0
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