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)); EK:s#
} @YMQbjbr
for(int i=0;i<nEndPos.length-1;i++) JmR) g
{ t[.wx.y&0
nEndPos = nStartPos[i+1]; G}lP'9/
} Ofyz,% |Q
nEndPos[nEndPos.length-1] = nFileLength; %Ny`d49&
} #xopJaY
} ?B&@
l9 |x7GB
XgfaTX*
//启动子线程 O;ty k_yM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; FZEK-]h.
for(int i=0;i<nStartPos.length;i++) Zy -&g:
{ ZL-YoMHc+_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '|\et aD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), R`RLq1WA
nStartPos,nEndPos,i); {c3u!}mW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YJ&K0%R
fileSplitterFetch.start(); bYKyR}e
} W:8*Z8?7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {\?zqIM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #()u=)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g]z[!&%Ahs
nEndPos = " + nFileLength); iZVMDJ?(Z]
// fileSplitterFetch[nPos.length-1].start(); U~mv1V^.
mh#dnxeR
KXgC]IO~
//等待子线程结束 &tULSp@J
//int count = 0; }Ot I8;>
//是否结束while循环 G$5N8k[2
boolean breakWhile = false; O>E2G]K]\
$hkMJ),T~
~)zoIM\
while(!bStop) A-GRuC
{ -,;Iob56!
write_nPos(); 9\/T #EP
Utility.sleep(500); Qr/8kWa0C
breakWhile = true; EzDj,!!<w
6T}bD[h4?
nC3U%*l
for(int i=0;i<nStartPos.length;i++) XcS8{
{ pX:FXzYQ
if(!fileSplitterFetch.bDownOver) p<|I!n&9
{ 93Yo}6>
breakWhile = false; 0`KB|=>
break; 1GnT^u y/
} <(]e/}
} s_=/p5\
if(breakWhile) Dj<]eG]
break; uhuwQS=X
VWlOMqL995
Fr}e-a
//count++; 959i2z
//if(count>4) K)Nbl^6x
// siteStop(); qzVmsxBNP
} 8?GS:+
P&/PCSf
^N!l$&=
System.err.println("文件下载结束！"); }LH>0v_<Y
} web=AQ5I4
catch(Exception e){e.printStackTrace ();} jb' hqz
} p%A(5DE
62B` Z5j#
Phsdn`,
//获得文件长度 5q`d=L,
public long getFileSize() Ojkbv
{ ^|6%~jkD5
int nFileLength = -1; W^2Q"c#7F
try{ {d\erG(
URL url = new URL(siteInfoBean.getSSiteURL()); ()}B]?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1n! JfsU
httpConnection.setRequestProperty("User-Agent","NetFox"); APT'2-I_
T/ CI?sn
s D]W/
int responseCode=httpConnection.getResponseCode(); rsP3?.E
if(responseCode>=400) uf*sI
{ 0gBD
processErrorCode(responseCode); _Cv({m&N
return -2; //-2 represent access is error %C= {\]-2~
} wSp1ChS k
"`DCXn#mB
krTH<- P
String sHeader; bA-=au?o5
'#SacJ\L7
Q{Gi**<
for(int i=1;;i++) #,O<E@E
{ ;T}#-`O_Im
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }Po&6^
//Utility.log(in.readLine()); Yn,dM~|Cc
sHeader=httpConnection.getHeaderFieldKey(i); R/ 7G
if(sHeader!=null) k/vE|
{ ?op6_a-wm
if(sHeader.equals("Content-Length")) hq.z:D
{ cLH|;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Bv$;yR
break; tw8@&8"
} yV:DR
} #F5O>9hA
else f/9]o
break; rUkiwqr~E
} J<:qzwh
} 6uQfe?aD
catch(IOException e){e.printStackTrace ();} ZD1UMB0$4
catch(Exception e){e.printStackTrace ();} y&\ J
"sz)~Q'W5
5gg_c?Vh/
Utility.log(nFileLength); '$~9~90?Z
__""!Yz
65RWaz;|
return nFileLength; OvU]|4h
} Tn[DF9;?
-p`hevRr
-san%H'
//保存下载信息（文件指针位置） ,,oiL
private void write_nPos() ]%(hZZ
{ )'M<q,@<(
try{ s4lkhoN\t
output = new DataOutputStream(new FileOutputStream(tmpFile)); ):eX*
output.writeInt(nStartPos.length); KYVB=14
for(int i=0;i<nStartPos.length;i++) )cB00*/
{ I ms?^`N
// output.writeLong(nPos); _ Onsfv
output.writeLong(fileSplitterFetch.nStartPos); -MoI{3a
output.writeLong(fileSplitterFetch.nEndPos); ,;C92XY
} $lci{D32,
output.close(); *G$tfb(
} JP9eNc[
catch(IOException e){e.printStackTrace ();} 'OSZ'F3PV
catch(Exception e){e.printStackTrace ();} nJ.pPzH2g
} !1!;}uzt
di`Ql._M
t/HMJ
//读取保存的下载信息（文件指针位置） {hK$6bD3^
private void read_nPos() V{;Mh u`+
{ GDP@M)~6*
try{ \?h +
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |h(!CFR
int nCount = input.readInt(); =)"60R7{
nStartPos = new long[nCount]; .Nr}V.?57
nEndPos = new long[nCount]; rE[*iq,#
for(int i=0;i<nStartPos.length;i++) p+#J;.
{ Bm"jf]
nStartPos = input.readLong(); +"Ek? )?
nEndPos = input.readLong(); }Gr5TDiV0\
} !)ey~Suh
input.close(); N%/Qc hu
} B+eB=KL
catch(IOException e){e.printStackTrace ();} g=Q#2/UQ<
catch(Exception e){e.printStackTrace ();} x$I~y D
} /K<Xr[z~y
^10*s,(uS?
pq+Gsu1^
private void processErrorCode(int nErrorCode) md_aD
{ VR2BdfKU,
System.err.println("Error Code : " + nErrorCode); ,\4@Ao
} \TkBV?W
pNr3u
zm\=4^X
//停止文件下载 w<&Nn`V
public void siteStop() ]K?z|&N|HK
{ 4vPQuk!
bStop = true; a*6x^R;)
for(int i=0;i<nStartPos.length;i++) +Vt@~Z4K
fileSplitterFetch.splitterStop(); O*rKV2\
rPkV=9ull,
bV|:MW<Wv
} <_8\}!
} ' ~lC85
//负责部分文件的抓取 ;2@MPx
**FileSplitterFetch.java {-J/ <a@
*/ Wk$[;>NU3
package NetFox; '81$8xxdY
,sP7/S)FR
qbu Lcy3
import java.io.*; #*j
import java.net.*; cG6Q$
h"Yi'
DY^q_+[V
public class FileSplitterFetch extends Thread { ypwVzCUG
Duj9PV`2
8fTuae$^
String sURL; //File URL Yq4_ss'nB
long nStartPos; //File Snippet Start Position kM*f9x
long nEndPos; //File Snippet End Position ,'m<um
int nThreadID; //Thread's ID oOBN
boolean bDownOver = false; //Downing is over lLxKC7b
boolean bStop = false; //Stop identical cgc|G
FileAccessI fileAccessI = null; //File Access interface .1.n{4z>:
0vQ@n7
fOm=#:O
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &9, 6<bToP
{ Nj*J~&6G
this.sURL = sURL; (ScL C
this.nStartPos = nStart; Xgn^)+V:
this.nEndPos = nEnd; 5@P2Z]Q
nThreadID = id; \;I%>yOIu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $dFEC}1t
} ?%i|].<-'
Cd#[b)d ?^
FGG Fi(
public void run() PbJn8o
{ *J=`"^BO
while(nStartPos < nEndPos && !bStop) bk}.^m!
{ ,;y5Mu8
])'22sY
2Prr:k
try{ D@!`b6
URL url = new URL(sURL); 0diQfu)Fi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;XSV}eLu
httpConnection.setRequestProperty("User-Agent","NetFox"); }ARWR.7Cc
String sProperty = "bytes="+nStartPos+"-"; H5S>|"`e`e
httpConnection.setRequestProperty("RANGE",sProperty); Q*ZqY
Utility.log(sProperty); Z9cch-u~
@ T'!;)
Dh BUMDoB
InputStream input = httpConnection.getInputStream(); .8uJ%'$)
//logResponseHead(httpConnection); qS*qHT(u19
9(QY~F
\'&:6\-fw
byte[] b = new byte[1024]; R#`hT
int nRead; q%bNT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L:IaJ?+?
{ fJn;|'H!
nStartPos += fileAccessI.write(b,0,nRead); l6:k|hrm;
//if(nThreadID == 1) D!Owm&We
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ry,_%j3
} aU<0<Dx
.<gAa"
xv]P-q0
Utility.log("Thread " + nThreadID + " is over!"); $T8Ni!#/C
bDownOver = true; <oS2a/Nd
//nPos = fileAccessI.write (b,0,nRead); /PE3>"|wE
} o_t2 Z
catch(Exception e){e.printStackTrace ();} \kF}E3~+#
} eA$9)K1GO
} J~V`"uo
<@.f#
-d[9mS
//打印回应的头信息 /~{8/u3
public void logResponseHead(HttpURLConnection con) T12?'JL^r
{ >7!4o9)c
for(int i=1;;i++) ?9mFI(r~
{ w[I%Id;E
String header=con.getHeaderFieldKey(i); X<Rh-1$8F
if(header!=null) ,v4Z[ (
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B#&U5fSw+0
Utility.log(header+" : "+con.getHeaderField(header)); 8b8ui
else eG72=l)Mz
break; cR 4xy26s
} "pa5+N&2-
} S7P](F=n#
NS6#od ZeV
GC?\GV
public void splitterStop() {# ;e{v
{ e-sMU
bStop = true; _M8Q%
} !`hiXDk*2
@`G_6<.`
-PbGNF
} afqLTWUS
1y$Bz?4
=SA@3)kHH
/* IVzJ|
**FileAccess.java ;Z-xum{
*//文件访问(定位，写) 3v :PBmE
package NetFox; B'"C?d<7
import java.io.*; S)Sv4Qm
V.Dqbv
^&am]W;T
public class FileAccessI implements Serializable{ %L.,:mtq)
$xNM^O
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0$b)@
RandomAccessFile oSavedFile; o/@.*Rj>Bg
long nPos; eLJW
k {_X%H/
MLtfi{;LH
public FileAccessI() throws IOException wQgW9546
{ N&K:Jp
this("",0); G4{ zt3{
} 9eo$Duws
*>h"}e41
U2\g Kg[-Q
public FileAccessI(String sName,long nPos) throws IOException c}kZx1
{ T~J6(,"
oSavedFile = new RandomAccessFile(sName,"rw"); ZE.nB- H
this.nPos = nPos; m{9m.~d
oSavedFile.seek(nPos); NVU@m+m~
} } 1^/[?
e7T"?s
`*mctjSN
public synchronized int write(byte[] b,int nStart,int nLen) `of 5h*k
{ j2\bCGY
int n = -1; <k-&Lh:o3
try{ =o^oMn
oSavedFile.write(b,nStart,nLen); RMUR@o5N
n = nLen; i 2hP4<;h
} J3KY?,g3O_
catch(IOException e) mRZC98$ @r
{ ;)s$Et%
e.printStackTrace (); wkOo8@J\
} 6+u}'mSj8
Eo 5p-
f=]+\0MQ
return n; Pc#8~t}2
} U+>!DtOYK
X<dQq`kZ
.I$Q3%s
} )XV|D
,X25-OFZ
,V'+16xW
/* izy7.(.a
**SiteInfoBean.java Tqz{{]%j~$
*/ :#s6,
package NetFox; bO]^TRaiJ
!#j y=A
43-mv1>.
public class SiteInfoBean { PeGA+0bm
92!1I$zi
T4dLuJl
private String sSiteURL; //Site's URL /yPFts_q
private String sFilePath; //Saved File's Path 1wP#?p)c
private String sFileName; //Saved File's Name JwG$lGNJ
private int nSplitter; //Count of Splited Downloading File 0$NcxbM
LsH&`G^<
'Vq <;.A
public SiteInfoBean() 8dgI&t
{//nSplitter的缺省值为5 mz$)80ly
//default value of nSplitter is 5 d2`m0U
this("","","",5); (8qD'(@
} > 2_xRn<P
1Z%^U ?
^0vK >
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 11t+ a,fM
{ BwMi@r =
sSiteURL= sURL; n6D9f~8"
sFilePath = sPath; 95LZG1]Rb
sFileName = sName; 3Kuu9<0
this.nSplitter = nSpiltter; qn) VKx=
~R^~?Y%+<
h&@A'om~
} QY2/mtI
h6J0b_3h4
lZ]x #v
public String getSSiteURL() ~Sy/q]4ys*
{ C".nB12
return sSiteURL; 7i^7sT8t
} +g/TDwyVH
sjl(
4)MKYhm
public void setSSiteURL(String value) ,dn6z#pb+
{ V&nTf100
sSiteURL = value; 1./uJB/
} /g$cQ=c
d&[Ct0!++u
Y'K+O
public String getSFilePath() JxI\ss?O
{ @CGci lS=
return sFilePath; `;KU^dH
} ueI1O/Mi
D<=x<.
o[Ojl.r<
public void setSFilePath(String value) ;k1\-
{ eh4`a<gC
sFilePath = value; 7G6XK
} MR4e.+#E
}/)vOUcEd
2stBW5v3
public String getSFileName() ((KNOa5
{ <zd_-Ysn
return sFileName; U~9Y9qzy,
} P`z#tDT^"
v9?hcJ=
R"@J*\;$T
public void setSFileName(String value) H}v.0R
{ '+?L/|'
sFileName = value; 6<aZr\Ufg
} aqL#g18
3JhT
f@JMDJ
public int getNSplitter() UqVcN$^b
{ GM]" $
return nSplitter; %Xe#'qNq)
} 73/DOF
$H\[yg>4
PSCzeR
public void setNSplitter(int nCount) 6(#fGH&[
{ RP!!6A6:
nSplitter = nCount; jhRg47A
} K<k!sh
} U&F1}P$fb
!4;A"B(
#kGgzO
/* "gt-bo.,
**Utility.java ,<Ag&*YE4
*/ 5hxG\f#}?
package NetFox; l]g /rs
x}^:Bs+j
@*Y"[\"$
public class Utility { mGZJ$|
$] ])FM"b
c>SFttbU
public Utility() u92);1R
{ ,\){-H/n
\,n|V3#G
#|92+
} 2OA0rH"v
cj[a^ ZH
//线程睡眠 3VI[*b
public static void sleep(int nSecond) 9\dpJ\
{ m8jQ~OS
try{ j\I{pW-
Thread.sleep(nSecond); ,(&p"O":
} dmR>u
catch(Exception e) |\}&mBR
{ @Sr{6g*I
e.printStackTrace (); (7X|W<xT
} [TW?sW^0
} z`Jcpt
lRk)
//日志 :CeK 'A\
public static void log(String sMsg) &gxWdG}qx]
{ JJQS7,vG
System.err.println(sMsg); QLPb5{>KDS
} iH`Q4
*dAQ{E(rO
*XU2%"Sc
public static void log(int sMsg) N1',`L5
{ ~cf*Oq
System.err.println(sMsg); ^cz4nW<
} A,'F`au
} 2@Nt6r
3 P=I)q
H1t`fyri2
/* xS'Kr.S
**TestMethod.java h&|S*
*/ IgmCZ?l&0
package NetFox; |&oTxx$S
M1mx{<]A
{py"Ob_
public class TestMethod { {`ghX%M(l
1u~CNHm
X7~^D[X
public TestMethod() i8h^~d2"
{ ///xx/weblogic60b2_win.exe R/WbcQ)
try{ q\$k'(k>35
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6"L,#aKm^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); : MEB] }
SiteFileFetch fileFetch = new SiteFileFetch(bean); QM) ob
fileFetch.start(); 5(\H:g\z
} |Wg!>g!
catch(Exception e){e.printStackTrace ();} E]P7u"1
yg^ 4<A
+^cjdH*
} j[RY
z 0}JiWR
D#k ~lEPub
public static void main(String[] args) u~~H'*EM
{ =j"bLX6;
new TestMethod(); _2a)b(<tF
} t?(fDWd|-
} W; zzc1v
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