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)); fhi}x(
} ?0)K[Kd'Y
for(int i=0;i<nEndPos.length-1;i++) 4(8c L?J`0
{ UDHOcb
nEndPos = nStartPos[i+1]; NXD-
} Sr+hB>{
nEndPos[nEndPos.length-1] = nFileLength; =1Plu5
} C\{A|'l!x
} m9h<)D'>
=2q#- ,t
S6bW r0XR
//启动子线程 rL<N:@HL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <ppdy,j:
for(int i=0;i<nStartPos.length;i++) 4{>r_^8
{ A}"|_&E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), we}xGb.u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v:lkvMq|=
nStartPos,nEndPos,i); ",apO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A":=-$)
fileSplitterFetch.start(); ^aqQw u
} l#uF%;GDX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uV|F3'jT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5$ How!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @Ez>?#z
nEndPos = " + nFileLength); #ChTel
// fileSplitterFetch[nPos.length-1].start(); 2fdN@iruB
9q]f]S.L
`*[Kmb\
//等待子线程结束 oW OR7)?r
//int count = 0; ZQ"dAR/y
//是否结束while循环 I484cR2.
boolean breakWhile = false; 5VE=Oo#&
.BjWZj
B<~AUf*y
while(!bStop) wmpQF<
{ "IS; o o$g
write_nPos(); ,3rsjoKhd
Utility.sleep(500); #@nPB.
breakWhile = true; !"FEp
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\[!{tbK`2
for(int i=0;i<nStartPos.length;i++) G%Lt>5*!nE
{ qo:Zc`t(R
if(!fileSplitterFetch.bDownOver) {^ BZ#)m|
{ zEjl@Kf
breakWhile = false; */~|IbZ`o
break; [#wt3<d`)
} 3N]ushMO
} b+Sj\3fX
if(breakWhile) ql%K+4@
break; i=5!taxu}E
krGIE}5
`?T::&`
//count++; YS4"TOFw
//if(count>4) Q?hf2iw
// siteStop(); yl*%P3m|
} aQH]hLvs
A|Ft:_Y
ZYY`f/qi
System.err.println("文件下载结束！"); qAp<OJ
} };rEN`L
catch(Exception e){e.printStackTrace ();} gWro])3
} m,+E5^
K}q5,P(
},<Y \
//获得文件长度 ZC$u8$+P
public long getFileSize() n[BYBg1yG
{ {Mo[C%
int nFileLength = -1; uD{^1c3x
try{ QP"5A7=m
URL url = new URL(siteInfoBean.getSSiteURL()); -^np"Jk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Rxw+`ru
httpConnection.setRequestProperty("User-Agent","NetFox"); @WXRZEz
pVl7]_=m
aeYz;&K
int responseCode=httpConnection.getResponseCode(); 2./z6jXW_
if(responseCode>=400) EWl9rF@I
{ ">B&dNrt
processErrorCode(responseCode); s o: o b}
return -2; //-2 represent access is error }.u[';q]S
} gdAd7 T
.R)Ho4CE
I+Y Z+
String sHeader; RYl{89
cEXd#TlY~X
<`q-#-V@
for(int i=1;;i++) w3iX "w
{ n\7>_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zWN]#W`
//Utility.log(in.readLine()); 0LGHSDb
sHeader=httpConnection.getHeaderFieldKey(i); X+;#^A3
if(sHeader!=null) ld%#.~Q
{ :\mdVS!o
if(sHeader.equals("Content-Length")) iyR5mA
{ g}?39?o4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8eCh5*_$
break; amQiH!}8R
} 'mv|6Y
} _x-2tnIxXv
else D41.$t[
break; )+)qFGVz
} NUBzc'qb
} zzC{I@b
catch(IOException e){e.printStackTrace ();} e*<pO@Uy
catch(Exception e){e.printStackTrace ();} nbw8YO(=
17:7w
2#R0Bd
Utility.log(nFileLength); K-(C5 "j_
7wrRIeES
t|&hXh{
return nFileLength; rWL&-AZQl
} u3X!O
.^- I<4.
.lgm"
//保存下载信息（文件指针位置） ()Img.TIt
private void write_nPos() .<K9Zyi
{ p:|7d\r
try{ F(U(b_DPM
output = new DataOutputStream(new FileOutputStream(tmpFile)); V+u0J"/8
output.writeInt(nStartPos.length); 8`<3rj
for(int i=0;i<nStartPos.length;i++) bHDZ=Ik
{ s2tNQtq0W
// output.writeLong(nPos); HS.eK#:N
output.writeLong(fileSplitterFetch.nStartPos); (6)|v S
output.writeLong(fileSplitterFetch.nEndPos); Rs'mk6+
} Ngrj@_J
output.close(); S>[&]
} W Emh
catch(IOException e){e.printStackTrace ();} JFRbWQ0
catch(Exception e){e.printStackTrace ();} U d+6=Us{
} meD83,L~N
M VE:JNm
#E/|WT
//读取保存的下载信息（文件指针位置） +D h?MQt?
private void read_nPos() =4/K#cQ
{ %u?A>$Jn
try{ P?=}}DI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w!UIz[ajI
int nCount = input.readInt(); 0b=00./o
nStartPos = new long[nCount]; 9WL$3z'*
nEndPos = new long[nCount]; s_!F`[
for(int i=0;i<nStartPos.length;i++) Tn'o$J
{ o~x49%X<c
nStartPos = input.readLong(); >b*}Td~J
nEndPos = input.readLong(); ) Cm95,Y
} BE!WCDg,
input.close(); 7%|HtBXv^
} X-yS9E
catch(IOException e){e.printStackTrace ();} fHF*#
catch(Exception e){e.printStackTrace ();} u~'j?K.^
} G Mg|#DV
JGlp7wro
. N5$s2t
private void processErrorCode(int nErrorCode) SQdK`]4
{ FdxV#.BE
System.err.println("Error Code : " + nErrorCode); bL%-9BG
} M r~IVmtf
o3:h!(#G
}vX1@n7T6
//停止文件下载 <a(739IF
public void siteStop() [TmZ\t!5$
{ 2Gc0pBqx
bStop = true; aslb^
for(int i=0;i<nStartPos.length;i++) .|LY /q\A
fileSplitterFetch.splitterStop(); 9'O@8KB_
\k%j
RPTIDA))
} E`q)vk
} Zx|VOl,;
//负责部分文件的抓取 \lpvRZ\L&g
**FileSplitterFetch.java 9!Bz)dJ3
*/ LII4sf]
package NetFox; JF9r[%
U;]h/3P
*5" )3\/
import java.io.*; j-/F*P
import java.net.*; YZc{\~d
1{CVd m<9
nhB.>ReAi
public class FileSplitterFetch extends Thread { TdrRg''@
m>^#:JK
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String sURL; //File URL VBg M7d
long nStartPos; //File Snippet Start Position r4pR[G._
long nEndPos; //File Snippet End Position &bwI7cO
int nThreadID; //Thread's ID eq4Yc*|9
boolean bDownOver = false; //Downing is over M^y5 Dep
boolean bStop = false; //Stop identical 1v9#Fr Y
FileAccessI fileAccessI = null; //File Access interface <)$JA
q}p (p( N
z4s{a(Tsd
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 26-K:"
{ bSk)GZyH\d
this.sURL = sURL; $G#)D^-5G
this.nStartPos = nStart; +Y440Tz
this.nEndPos = nEnd; DP &*P/
nThreadID = id; ~ll+/w\4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ByW,YKMy
} 4u]>$?X1_
%H7H0%qW
]]V|]}<)m
public void run() aq]bF%7
{ ,M9Hdm
while(nStartPos < nEndPos && !bStop) Y'x+!&H
{ ft Rza
9:CM#N~?o
q=/ck
try{ O.'\GM
URL url = new URL(sURL); b[my5Ol
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HAGpM\Qa
httpConnection.setRequestProperty("User-Agent","NetFox"); @l&>C#K\
String sProperty = "bytes="+nStartPos+"-"; :cE~\BS&
httpConnection.setRequestProperty("RANGE",sProperty); `j(-y`fo
Utility.log(sProperty); uVLKR PY
LVNJlRK
)uH#+IU
InputStream input = httpConnection.getInputStream(); Q|nGY:98
//logResponseHead(httpConnection); t|cTl/i 4
k`r`ZA(kQ-
=o,6iJ^?$m
byte[] b = new byte[1024]; Qg gx:
int nRead; gP>`DPgb^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f/%QMhM:
{ nCdxn#|
nStartPos += fileAccessI.write(b,0,nRead); Nr0}*8#j
//if(nThreadID == 1) oz/Nx{bg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q,2 +\i
} eGlPi|
dW"=/UW
3W"l}.&ZJ"
Utility.log("Thread " + nThreadID + " is over!"); 6e At`L[K.
bDownOver = true; ]"-c?%L
//nPos = fileAccessI.write (b,0,nRead); MI|anM
} S2"HE`
catch(Exception e){e.printStackTrace ();} vUgMfy&
} Et+WLQ6)
} 7eQc14
y[I)hSD=
6%fF6
//打印回应的头信息 tF~D!t@
public void logResponseHead(HttpURLConnection con) o_on/{qz
{ {_>}K
for(int i=1;;i++) K_CE.8G&{
{ iCh,7I,m
String header=con.getHeaderFieldKey(i); 6@geakq
if(header!=null) K_[B@( Xl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); J=AF`[
Utility.log(header+" : "+con.getHeaderField(header)); ?bH!|aW(H
else ^mCKRWOP'
break; \LQ54^eB
} Q*8=^[x
} NaYr$`
ynU20g
GilmJ2<
public void splitterStop() Kz2s{y~?
{ s|o+ Im
bStop = true; 4~mmP.c
} ^Qa!{9o[
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0XUWK@)P
} y6N }R
hSF4-Vvb
_!Ir|j.A
/* ;A;FR3=)
**FileAccess.java "vN~7%
*//文件访问(定位，写) hYEUiQ
package NetFox; QK@[b3-h1
import java.io.*; T6fm`uL&L
rJ)8KY>
T~-OC0
public class FileAccessI implements Serializable{ TjLW<D(i>
Vs@H>97,G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J0O wzO
RandomAccessFile oSavedFile; < r7s,][&
long nPos; o-r00H|
Z@QJ5F1y
ylwh_&>2
public FileAccessI() throws IOException |++\"g
{ /O&{fo
this("",0); ,RIC _26
} B"=w9w]
_2E*
xfADks2w
public FileAccessI(String sName,long nPos) throws IOException yHjuT+/wM,
{ \S[I:fw#&
oSavedFile = new RandomAccessFile(sName,"rw"); 8(|lP58~
this.nPos = nPos; JJVdq-k+`
oSavedFile.seek(nPos); PiZU_~A
} (hFyp}jkk
$hq'9}ASOL
SVJt= M
public synchronized int write(byte[] b,int nStart,int nLen) RSK5 }2
{ $Z[W}7{pt#
int n = -1; -wrVhCd~g]
try{ j$Wd[Ja+O
oSavedFile.write(b,nStart,nLen); lmpBf{~ S
n = nLen; 9HBRWh6
} $v0beN6MG
catch(IOException e) HGl.dO7NU
{ r0(*]K:.
e.printStackTrace (); ]o3K
} EaUO>S
#d;/Me
4"~l^yK
return n; c=#V*<
} L wP
qEajT"?
~x6<A\
} 83g$k 9lG.
s5 ($b
$ n"*scyI
/* wjc&S'[
**SiteInfoBean.java w~wg[d
*/ "'v^X!"
package NetFox; T3,}CK#O
}C!g x6
:hFKmoy#
public class SiteInfoBean { 3:"w"0[K3
~Y3X*
i.Z iLDs\7
private String sSiteURL; //Site's URL ~>B`T%=H
private String sFilePath; //Saved File's Path r}i}4K[1
private String sFileName; //Saved File's Name 45.Vr[FS.
private int nSplitter; //Count of Splited Downloading File 8~ wP?
pxb4x#CC
8KMo!p\i
public SiteInfoBean() t+Au6/Dx?
{//nSplitter的缺省值为5 |*n B2
//default value of nSplitter is 5 ,Vfjt=6]}
this("","","",5); )];Bo.QA
} *"Uf|
L6Io u
$(+#$F<eo+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pj#ls
{ Z~1uyr(
sSiteURL= sURL; uZe"M(3r$
sFilePath = sPath; d3"QCl
sFileName = sName; [ahK+J
this.nSplitter = nSpiltter; TE% i
J>8kJCh9g
8e32NJ^k~
} X+kgx!u'y
2Og<e|
,#U[)}im
public String getSSiteURL() W^YaC (I
{ 8F9x2CM-[C
return sSiteURL; A~({vb'
} W5,&*mo
t-Uo
#\Zr$?t|V
public void setSSiteURL(String value) eI,H
{ DIw9ov>k
sSiteURL = value; y}1Pc*
} *-(8Z>9
6{!Cx9V
mx5#K\
public String getSFilePath() qPBOt;N
{ )kDB*(?
return sFilePath; nrg$V>pD
} 2p~}<B
OJiwI)a9
x;{Hd;<YF
public void setSFilePath(String value) K5!OvqzG
{ dngG=
sFilePath = value; M $f6.j
} h43py8v
Cy dV$!&mP
+w/B3b
public String getSFileName() b/?)_pg
{ 2N{^V?:
return sFileName; 4W#DLip9
} +{0v@6<(02
>&ENrvaJ
0f#xyS 3
public void setSFileName(String value) ?Wc+ J4
{ [kf6bf@
sFileName = value; 9yz@hdG
} %n6NVi_[
/@B2-.w
WK0:3q(P
public int getNSplitter() 6MNrH
{ Z/czAr@4
return nSplitter; 7=/iFv[
} /cT6X]o8
ZUkM8M$c
)AR-b8..o
public void setNSplitter(int nCount) hE`d@
{ rCczQ71W
nSplitter = nCount; 7.ein:M|CB
} N'&>bO?@`
} x4wTQ$*1
'<<@@.(f
}s@IQay+
/* ?Sa,n^b*H
**Utility.java >]gB@tn[
*/ <X4f2z{T{@
package NetFox; /.!&d^
F02TM#Zi
mk!8>XvM
public class Utility { $V?sD{=W
Q$]1juqg
C6a-
public Utility() B]<N7NYn1
{ 047PlS
kv2o.q
uaKbqX
} ^mFsrw
;R2A>f~
//线程睡眠 }b}jw.2Wu
public static void sleep(int nSecond) *?uUP
{ tB`"gC~
try{ DO*6gzW
Thread.sleep(nSecond); !.O[@A\.-
} N2[jBy8M
catch(Exception e) l$c/!V[3
{ <kwF<J
e.printStackTrace (); r1RM7y
} <[}zw!z
} dQ-g\]d|
\vc&V8
//日志 l?J[K
public static void log(String sMsg) dJ])`S
{ U*sQ5uq
System.err.println(sMsg); )c9Xp:
} pG)dF@
8L/XZ)
KV&6v`K/N
public static void log(int sMsg) tCR~z1
{ BOM0QskLf
System.err.println(sMsg); Xf7]+
} w^nA/=;r
} .:Wp9M
<^KW7M}w*c
tK*y/S
/* i-4L{T\K
**TestMethod.java DQV9=
*/ |+sAqx1IF
package NetFox; $;=?[Cn
Da6l=M
v<l]K$5J&
public class TestMethod { \/Q~C!
j%]sym
=c&.I}^1L
public TestMethod() ~Cynw(
{ ///xx/weblogic60b2_win.exe ?LU>2!jN
try{ \fI05GZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :2vuc!Pu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |{ZdAr.;
SiteFileFetch fileFetch = new SiteFileFetch(bean); FoZI0p?L)9
fileFetch.start(); e!w2_6?3
} Z]k@pR !
catch(Exception e){e.printStackTrace ();} &><b/,]
I7Abf7>*Q
7aPA+gA/
} K~3Y8ca
yqtHlz%
4sH?85=j
public static void main(String[] args) jMS>B)'TO
{ 6jm/y@|F!
new TestMethod(); THK^u+~LM
} N;>s|ET
} tk8\,!9Q
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