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)); e<9nt [
} o B6"D
for(int i=0;i<nEndPos.length-1;i++) /#:RYM'Tu
{ ?G?=,tV
nEndPos = nStartPos[i+1]; 2M&4]d
} i[\[xfk
nEndPos[nEndPos.length-1] = nFileLength; ,6M-xSDs
} ,j_{IL690
} &us8,x6yg
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K&)a3Z=(.
//启动子线程 ]#BXaBVMY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]Rj"/(X,
for(int i=0;i<nStartPos.length;i++) >`{i[60r
{ {Y0I A97,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rM?D7a{q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mCz6&
nStartPos,nEndPos,i); +XpRkX&-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]UgAz
fileSplitterFetch.start(); ~JZLfw
} /yykOvUO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '|d (<.[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~HYP:6f
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .oK7E(QJ
nEndPos = " + nFileLength); &\"fH+S
// fileSplitterFetch[nPos.length-1].start(); QIV<!SO
p9s~WD/K
25ayYO%PTc
//等待子线程结束 cw5YjQ8 9
//int count = 0; L}21[ N~ky
//是否结束while循环 &R5M&IwL
boolean breakWhile = false; *z+\yfOO"
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:mJM=FeJ
while(!bStop) $U8ap4EXM
{ gx6&'${=#
write_nPos(); 8uT6QCf
Utility.sleep(500); .|aSGvE
breakWhile = true; aJ}sYf^
pc.0;gN
3?%kawO&
for(int i=0;i<nStartPos.length;i++) <>e<Xd:77{
{ W@ Z=1y
if(!fileSplitterFetch.bDownOver) w-#0k.T
{ H9>&"=".
breakWhile = false; >|'6J!Op
break; #KK(Z\;
} h7y*2:l6
} YSwD#jO0
if(breakWhile) c|.:J]
break; PaDT)RrEM
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<+$S{Z.
//count++; E1C8yIF
//if(count>4) >WDpBn:
// siteStop(); -of= Lp
} ('lnQD.Hd
Za f)
<+b:
System.err.println("文件下载结束！"); V8sY7QK=
} q@sH@-z4]
catch(Exception e){e.printStackTrace ();} E^YbyJ=1
} z8!u6odu %
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CC09:L?
//获得文件长度 eLTNnz
public long getFileSize() YiJu48J
{ Q&#:M>!|
int nFileLength = -1; Yq Fzbm{\
try{ d5=xOEv; :
URL url = new URL(siteInfoBean.getSSiteURL()); lC4By,1*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -Q@d
httpConnection.setRequestProperty("User-Agent","NetFox"); Jzdc'3dq
6~8 RFf"
h0eo:Ahi
int responseCode=httpConnection.getResponseCode(); m2! 7M%]GC
if(responseCode>=400) z K(5&u
{ "EHc&,B`
processErrorCode(responseCode); ;MMFF{
return -2; //-2 represent access is error </=PN1=A
} c[y8"M5
U .Od
=_H39)|T
String sHeader; { &'TA
@j (jOe
#TWc` 8
for(int i=1;;i++) <S}qcjG
{ kW~F*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?c2TT Q
//Utility.log(in.readLine()); o{he)r6)_
sHeader=httpConnection.getHeaderFieldKey(i); VM,ZEt3Vy
if(sHeader!=null) #Kl2K4
{ +o3g]0
if(sHeader.equals("Content-Length")) 8bGq"!w-
{ 8<kme"%s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AWDjj\Q4
break; >gZz`CH
} vf=
} U %ESuq#
else 2T5xSpC
break; +i^s\c!3;
} gAj)3T@
} `Z/IW
catch(IOException e){e.printStackTrace ();} 9CNHjs+-}s
catch(Exception e){e.printStackTrace ();} "(NHA+s/
@5y(>>C}8%
vxeT[/6i
Utility.log(nFileLength); `Ek!;u>
r$F]e]Ic\
p.9v<I%0
return nFileLength; ptR
} ;Kf|a}m-
XOCau.#
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//保存下载信息（文件指针位置） nIjQLx
private void write_nPos() 4I-p/&Q
{ 5u46Vl{
try{ qX(%Wn;n
output = new DataOutputStream(new FileOutputStream(tmpFile)); gQuw|u
output.writeInt(nStartPos.length); L0kNt &di
for(int i=0;i<nStartPos.length;i++) vb- .^l
{ ?I'-C?(t@1
// output.writeLong(nPos); '-IT@}
output.writeLong(fileSplitterFetch.nStartPos); r?!xL\C\
output.writeLong(fileSplitterFetch.nEndPos); 8zC k9&
} m GhJn
output.close(); }$U[5wL,_
} 'j_H{kQy
catch(IOException e){e.printStackTrace ();} >bN~p
catch(Exception e){e.printStackTrace ();} <L~xR5
} Gme$FWa
DANSexW
GC[{=]}9U
//读取保存的下载信息（文件指针位置） RfBb{?PP)
private void read_nPos() L"iyjL<M
{ ~ ZL`E
try{ Fnpn_O XlH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t^,Qy.L0
int nCount = input.readInt(); 358/t/4{p
nStartPos = new long[nCount]; Pm^N0L9?q
nEndPos = new long[nCount]; ~(j'a!#Vvk
for(int i=0;i<nStartPos.length;i++) xLI{=sL
{ U 0RfovJ
nStartPos = input.readLong(); HF: T]n,
nEndPos = input.readLong(); LUNs|\&
} Wi?%)hur
input.close(); BozK!"R_<
} <83gn :$
catch(IOException e){e.printStackTrace ();} qb4;l\SfT
catch(Exception e){e.printStackTrace ();} c@-K
} Zd U{`>v
1Wk EPj,
\83A|+k
private void processErrorCode(int nErrorCode) g/,Bx!'8p
{ oqba:y;AR
System.err.println("Error Code : " + nErrorCode); ms7 7{A3
} %^=!s
ocqB-C]
Tud1xq
//停止文件下载 g>xUS_d>
public void siteStop() '$XHRS/q]
{ R.H\b!
bStop = true; *+j{9LK
for(int i=0;i<nStartPos.length;i++) 2A}uqaF
fileSplitterFetch.splitterStop(); =>0M3 Qh{
S<3!oDBs
wDSUMB<?
} m"(d%N7
} {[5L96RH%
//负责部分文件的抓取 SP*JleQN
**FileSplitterFetch.java fG2&/42J
*/ (kQ.tsl
package NetFox; (+LR u1z
qH Ga
^:!(jiH
import java.io.*; @xm~T|[7
import java.net.*; {!1n5a3" 1
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G;HlII9x[
public class FileSplitterFetch extends Thread { 2c~?UK[1
^i+z_%V
zI&4k..4
String sURL; //File URL zQ5jx5B":
long nStartPos; //File Snippet Start Position O;0<^M/0G
long nEndPos; //File Snippet End Position H='9zqYZ<W
int nThreadID; //Thread's ID GHJ=-9{YL
boolean bDownOver = false; //Downing is over < mK
boolean bStop = false; //Stop identical '?G[T28
FileAccessI fileAccessI = null; //File Access interface !)/iRw9re
"YzTMKu
oT)VOkFq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [du>ff
{ )fMX!#KP
this.sURL = sURL; \U*-w:+@
this.nStartPos = nStart; `Kc %S^C'
this.nEndPos = nEnd; [Ht."VxR
nThreadID = id; FPMSaN P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cF&h$4-
} UW/3{2
Ac!&j=ZE
+%#MrNM'
public void run() l?JO8^Nn
{ jqGo-C~
while(nStartPos < nEndPos && !bStop) 0"^oTmQN
{ 9U<)_E<y
5Vqmv<F;$Z
2b4pOM7W
try{ J7?)$,ij%
URL url = new URL(sURL); C*s0r;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rF'^w56
httpConnection.setRequestProperty("User-Agent","NetFox"); R'9@A\7#
String sProperty = "bytes="+nStartPos+"-"; %V%#y $l
httpConnection.setRequestProperty("RANGE",sProperty); JQ@`EV9,
Utility.log(sProperty); 9<A\npD
v!#`W
B!r48<p
InputStream input = httpConnection.getInputStream(); kh?#={]Z
//logResponseHead(httpConnection); ui56<gI-
PF'5z#] NP
f_4S>C$
byte[] b = new byte[1024]; hdf8U
int nRead; eY4`k
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) YoF\MT]W
{ 1>@]@ST[:
nStartPos += fileAccessI.write(b,0,nRead); zK>'tFU
//if(nThreadID == 1) \Qi#'c$5+a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [t
} => uVp
~t${=o430
?|">),
Utility.log("Thread " + nThreadID + " is over!"); }+dM1O
bDownOver = true; O&3r*vd
//nPos = fileAccessI.write (b,0,nRead); #U$YZ#B
} X&9^&U=e
catch(Exception e){e.printStackTrace ();} w(V?N'[
} Ql q#Zdru
} W.J:.|kt
%89"A'g
!qTpQ5Dm
//打印回应的头信息 n~,]KdU]
public void logResponseHead(HttpURLConnection con) 8sR
{ UU.mdSL
for(int i=1;;i++) B;z>Dd,Y_x
{ #0?"J)
String header=con.getHeaderFieldKey(i); 8g[(nxI~
if(header!=null) Ho)t=qn
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =wIdC3Ph
Utility.log(header+" : "+con.getHeaderField(header)); yp[<9%Fi
else dThn?
break; d^Zo35X
} u+mjguIv
} Q$?7)yyu+
7cUR.PI#Q
%UUp=I
public void splitterStop() Ok}{jwJ%W;
{ ReI=4Jq11
bStop = true; N?a1sdR
} P&[Ft)`
NIGB[2V(
mh A~eJ
} 'ZGT`'ri
hF{x')(#l
d`?U!?Si
/* YW?7*go'Z
**FileAccess.java `W"a!,s2
*//文件访问(定位，写) K2x6R
package NetFox; d,Cz-.'sOf
import java.io.*; 0a2$P+p
R<n8M"B
L,C? gd@"
public class FileAccessI implements Serializable{ aPD?Bh>JU
$f<eq7rRe
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }t@f|TX
RandomAccessFile oSavedFile; m4Phn~>Gg
long nPos; 3}>:
L _vblUDq
'DCKD4@C/
public FileAccessI() throws IOException }b_R5U$@@
{ lfxuc7Rdla
this("",0); Bmx(qE
} C<[d
w8 ?Pb$Fe
bGZhUEq
public FileAccessI(String sName,long nPos) throws IOException C1X}3bB
{ d98))G~W
oSavedFile = new RandomAccessFile(sName,"rw"); r/mA2
this.nPos = nPos; a&$Zpf!!
oSavedFile.seek(nPos); =@xN(](
} J 6(~>g
&K5C=]4
Y%78>-2L
public synchronized int write(byte[] b,int nStart,int nLen) y2z{rd
{ qpb/g6g
int n = -1; cm@jt\D
try{ ]$m#1Kj
oSavedFile.write(b,nStart,nLen); " Sc5qG
n = nLen; A#v|@sul
} zW%>"y
catch(IOException e) 7))y}N:p
{ Q=d.y&4%
e.printStackTrace (); EX[B/YH
} 4=u+ozCG
N@k3$+ls
d>lt
return n; =E&b=
} zWy ,Om8P
If~95fy~c
W3De|V^
} CTl(_g
kcLj Kp
7]p>XAb
/* _^_5K(Uq
**SiteInfoBean.java E)C.eW /
*/ ~'NX~<m
package NetFox; yOX&cZ[
%9t{Z1$
{I4%
public class SiteInfoBean { @)o0GHNP
xLA~1ZSVJw
j_!bT!8
private String sSiteURL; //Site's URL }TSgAwsbC
private String sFilePath; //Saved File's Path MVeFe\r
private String sFileName; //Saved File's Name F(d:t!
private int nSplitter; //Count of Splited Downloading File PXV)NC
ETM2p1ru0
K@q&HV"'.
public SiteInfoBean() qOW#Q:T
{//nSplitter的缺省值为5 bsB},pc
//default value of nSplitter is 5 _~tm7o+js
this("","","",5); FXS^^p P
} y&1%1 #8F
uCw>}3
RG&I\DTyt
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }-d)ms!
{ EbCIIMbe"
sSiteURL= sURL; K'x4l,rq
sFilePath = sPath; fi=0{
sFileName = sName; dw~[9oh
this.nSplitter = nSpiltter; ):3MYSqX
*~cqr
3I|O^
} \,2gTi,=
w"{bp
'0]r<O
public String getSSiteURL() E_~x==cb
{ Yg/}ghF\
return sSiteURL; q7|:^#{av
} #;`Oj
xZX`%f-
W$r^
public void setSSiteURL(String value) @cZ\*,T
{ fb23J|"
sSiteURL = value; t\zbEN
} 7skljw(
ZT6V/MD7T.
0x\2#i
public String getSFilePath() 7!pLK&_
{ (qUK7$
return sFilePath; [q1Unm
} }g>kpa0c
Y=E9zUF
Rv,82iEKs
public void setSFilePath(String value) S`=n&'
{ hd5$yU5JQ
sFilePath = value; IhE9snJ[
} (VyA6a8
T'.[F
#EJP(wXa
public String getSFileName() JT04vm4
{ 3E,DipHg
return sFileName; FqwIJ|ct
} \ZMP_UU(
wFvT0
Cc!J1)
public void setSFileName(String value) s O=4IBE
{ HMV)U{
sFileName = value; 4@6<
} W .U+.hR
T^]7R4Fg
/YFa ;2 W
public int getNSplitter() Q/py qe G
{ qEQAn/&
return nSplitter; b,Ke>.m
} Nt~x&s
^LVk5l)\>g
9/@ &*
public void setNSplitter(int nCount) Me,<\rQ
{ !MoOKW
nSplitter = nCount; XFQNr`
} m;o4Fu
} ($62o&I
4z_n4=
@r<b:?u
/* =WK04\H
**Utility.java e[{mVhg4E
*/ 89Z#|#uM5
package NetFox; d;=u
!^iwQ55e2A
_{$fA6C
public class Utility { qfYG.~`5
w{`Acu
PNpu*#Z`
public Utility() qnJ50 VVW
{ Uyk,.*8"
BSgTde|3y
=((yWn+t
} ^I`a;
Blk}I
//线程睡眠 'Jydu
public static void sleep(int nSecond) xQU"A2{}>
{ 3z3_7XI
try{ .'j29 6[u
Thread.sleep(nSecond); $:EG%jl
} Uw)=WImz[
catch(Exception e) CxDcY
{ 6+3$:?
e.printStackTrace (); jj,r <T
} l5k?De_(x
} ORBxD"J&
9x?'}
//日志 8sg|MWSU
public static void log(String sMsg) ?:igumeYX
{ E'EcP4eL
System.err.println(sMsg); gn)R^
} ){P^P!s$
_ym"m,,7?
!E0!-UpY
public static void log(int sMsg) ag8`O&+
{ {eQWO.C{
System.err.println(sMsg); GeV+/^u
} .z-UOyer
} UpfZi9v?W
g_aCHEFBv
W5SNI>|E
/* &= eYr{
**TestMethod.java 8(lR!!=q
*/ L:@fP~Erh
package NetFox; }y6q\#G
#U ASH&
pRi<cO
public class TestMethod { C6jR=@42Q
zN!j%T.e
BStk&b
public TestMethod() kOjf #@c
{ ///xx/weblogic60b2_win.exe Lm6**v
try{ u =J&~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a#[-*ou`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3FNT|QF
SiteFileFetch fileFetch = new SiteFileFetch(bean); U|5-0u5
fileFetch.start(); ,_ .v_
} S3Y2O x
catch(Exception e){e.printStackTrace ();} P@0Y./Ds
|"]PCb)!
I=IjdwbH
} wK!~tYxP
h|)vv4-d|
Vrkf(E3_V
public static void main(String[] args) , ZFE(
{ (= ;N{u
new TestMethod(); Riry_
} O!&,5Dy
} F9flSeN
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