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)); ^|@t2Rp@
} h+k:G9;sS
for(int i=0;i<nEndPos.length-1;i++) +OFq=M
{ `A@{})+
nEndPos = nStartPos[i+1]; ^CUeq"GYoZ
} N|c;Qzl
nEndPos[nEndPos.length-1] = nFileLength; D6,rb 9
} 4@PH5z
} !>B|z=
,?GEL>F
{g?$u
//启动子线程 8(UUc>g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^Bw2y&nN
for(int i=0;i<nStartPos.length;i++) U2=l; R{
{ ,K Ebnk|i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z(p kj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }EmNSs`$r
nStartPos,nEndPos,i); 'AN3{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hm|8ydNs
fileSplitterFetch.start(); 6[kp#
} Z 6^AO=3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c>~"Z-VtX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `;-K/)/x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "?|sC{'C4j
nEndPos = " + nFileLength); +0mU)4n/
// fileSplitterFetch[nPos.length-1].start(); 4I7}
nwh7DUi
&MnS( 82L
//等待子线程结束 >3V{I'^^-
//int count = 0; T]d9tX-
//是否结束while循环 h#9X0u7j
boolean breakWhile = false; M]YK]VyG
Z@fMU2e=Z
u1F@VV{
while(!bStop) Jg=[!j0(
{ )CQ'kHT<e
write_nPos(); z=>U>
Utility.sleep(500); <A +VS
breakWhile = true; 59:Xu%Hp
'Z#8]YP`
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for(int i=0;i<nStartPos.length;i++) (]0JI1 d
{ 8^CdE*a
if(!fileSplitterFetch.bDownOver) =Jfo=`da
{ tgy*!B6a~
breakWhile = false; 4QODuyl2H
break; !Mp.jE
} k3::5&
} qc_c&
if(breakWhile) ZI4[v>
break; :@zz5MB5@
g$<Sh.4A
Md_S};!QN6
//count++; v'(p."g
//if(count>4) bcFG$},k
// siteStop(); e[f}Lxln
} Y.&nxT95=
>[;+QVr;
@l:\0cO
System.err.println("文件下载结束！"); OnE#8*8
} iB1"aE3
catch(Exception e){e.printStackTrace ();} 1e.V%!Xk
} m,KG}KX
XVcY?_AS#
(LzVWz m
//获得文件长度 Lu,72i0O ^
public long getFileSize() Tg|0!0qD]F
{ &GF@9BXI3
int nFileLength = -1; zil^^wT0J
try{ hw/:
URL url = new URL(siteInfoBean.getSSiteURL()); oUrNz#U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Vvk1 D(
httpConnection.setRequestProperty("User-Agent","NetFox"); @&(0]kZ6
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int responseCode=httpConnection.getResponseCode(); rM/Ona2x
if(responseCode>=400) KECo7i=e
{ &5:83#*Oj
processErrorCode(responseCode); {%W'Zx
return -2; //-2 represent access is error y/57 >.3
} I;xrw?=\L
g,Z8I;A^
IzPnbnS}
String sHeader; CX/ _\0G4
d>[=]
k I
for(int i=1;;i++) (/TYET_H
{ ]t$wK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &`+tWL6L
//Utility.log(in.readLine()); gXZl3
sHeader=httpConnection.getHeaderFieldKey(i); hKo& ZWPq
if(sHeader!=null) pRyePxCDj)
{ $m{-I=
if(sHeader.equals("Content-Length")) E(]39B"i
{ }pqnF53
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F(+,M~
break; g{{DC )>
} a=n*}.
} aQzDOeTi
else ,gAa9
break; oD1rt>k
} fS9TDy
} aX CVC<l
catch(IOException e){e.printStackTrace ();} u7 s-
catch(Exception e){e.printStackTrace ();} Msj(>U&}+
ejs_ ?
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Utility.log(nFileLength); a`/\0~
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return nFileLength; FfEP@$
} CshYUr -
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WBc,/lgZ
//保存下载信息（文件指针位置） ux>wa+XFa
private void write_nPos() cV8Bl="gqe
{ O^/z7,
try{ p1}umDb%
output = new DataOutputStream(new FileOutputStream(tmpFile)); rjk{9u1a"
output.writeInt(nStartPos.length); G,o5JL"t
for(int i=0;i<nStartPos.length;i++) JK.<(=y\
{ $W}YXLFj?
// output.writeLong(nPos); 4WspPHj
output.writeLong(fileSplitterFetch.nStartPos); 1nGpW$Gx
output.writeLong(fileSplitterFetch.nEndPos); 2h=QJgpCG
} n:dnBwY
output.close(); f%#q}vK-
} (rTn6[*
catch(IOException e){e.printStackTrace ();} lqaOLZH
catch(Exception e){e.printStackTrace ();} ,u.G6"<
} jimWLF5Q5"
&Ul8h,qw
o/dj1a~U
//读取保存的下载信息（文件指针位置） y}5:CZ
private void read_nPos() ULT,>S6r
{ -!Ov{GHr0
try{ y6#AL<W@=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MgpjC`
int nCount = input.readInt(); $c^,TAN
nStartPos = new long[nCount]; 3.0t5F<B
nEndPos = new long[nCount]; pUV4oyGV
for(int i=0;i<nStartPos.length;i++) Uw!N;QsC
{ Pi/V3D)B
nStartPos = input.readLong(); kH4xP3. i
nEndPos = input.readLong(); $X\deJ1Hi
} )\O;Rt(
input.close(); I 0vJJP#
} 8cKP_Ec
catch(IOException e){e.printStackTrace ();} n?a?U:
catch(Exception e){e.printStackTrace ();} Q}zd!*
} 1@}s:
.#Vup{.
Al}D~6MD
private void processErrorCode(int nErrorCode) S:= _o
{ !_i;6UVG
System.err.println("Error Code : " + nErrorCode); nNc>nB1
} V'iT>
Y%zYO
[\BLb8
//停止文件下载 B!j7vXM2
public void siteStop() .X.,.vHx
{ $R&K-;D/8
bStop = true; v?O6|0#x
for(int i=0;i<nStartPos.length;i++) GS)4,.
fileSplitterFetch.splitterStop(); Kry^47"
L9}%tEP
B'}pZOa[Wb
} n.l7V<1
} G4<M@ET
//负责部分文件的抓取 a[Y\5Ojm
**FileSplitterFetch.java hI6Tp>b*~
*/ H$M{thW
package NetFox; BJ*8mKi h
G2 {R5F !
>{1 i8 b@
import java.io.*; n=iL6Yu(
import java.net.*; =zsA@UM0
,^n5UA`PK
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public class FileSplitterFetch extends Thread { YQ$Wif:@(n
nBg tK
nhImO@Q:
String sURL; //File URL E{8-VmY
long nStartPos; //File Snippet Start Position Sv>bU4LHf
long nEndPos; //File Snippet End Position bdYx81
int nThreadID; //Thread's ID ~q,Wj!>Ob
boolean bDownOver = false; //Downing is over Rm&4Pku
boolean bStop = false; //Stop identical hanS8
FileAccessI fileAccessI = null; //File Access interface hd%O\D?
/6@$^paB
s`dwE*~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >HRL@~~Z
{ W*WSjuFr2
this.sURL = sURL; J#) %{k_
this.nStartPos = nStart; X%R)
this.nEndPos = nEnd; U$m[{r2M
nThreadID = id; {8e4TD9E0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :pw6#yi8`
} \R|qXB $
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public void run() g^)8a;/c
{ oR@1/lV
while(nStartPos < nEndPos && !bStop) (yO8G-Z0
{ 'z$!9ufY,
Aa!#=V1d
.T*89cEu
try{ j21>\K!p
URL url = new URL(sURL); a0)]W%F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LB\+*P6QM
httpConnection.setRequestProperty("User-Agent","NetFox"); ;=lQMKx0
String sProperty = "bytes="+nStartPos+"-"; @!KG;d:l
httpConnection.setRequestProperty("RANGE",sProperty); UZ-[vD1n
Utility.log(sProperty); neBcS[
/I~(*X
$,8}3R5}
InputStream input = httpConnection.getInputStream(); J/>9w
//logResponseHead(httpConnection); ["BD,mB
Xf%wW[~
zL=PxFw0
byte[] b = new byte[1024]; ,/Al'
int nRead; s<'WTgy1i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #McX
{ X*< !_3
nStartPos += fileAccessI.write(b,0,nRead); i-M<_62c
//if(nThreadID == 1) (_nU}<y_i
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &pFP=|Pq
} %d^ =$Q
LA4,o@V`
vT;~\,M
Utility.log("Thread " + nThreadID + " is over!"); d Z P;f^^
bDownOver = true; `%$l b:e
//nPos = fileAccessI.write (b,0,nRead); w\%AR1,rs
} tk66Ggi[K
catch(Exception e){e.printStackTrace ();} fD~f_Wr
} 8c<OX!
} a"!r]=r
+L-(Lz[p
!)HB+yr
//打印回应的头信息 il~A(`+YO
public void logResponseHead(HttpURLConnection con) Jl-:@[;
{ 2@>#?c7
for(int i=1;;i++) LB/1To
{ bF c %
String header=con.getHeaderFieldKey(i); fp2uk3Bm[
if(header!=null) &d@N3y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [;$9s=:[
Utility.log(header+" : "+con.getHeaderField(header)); ;t\C!A6
else I`uOsZBO/
break; _5H0<%\
} UE 1tm
} !~-@p?kW/
4%>2>5
v O@7o
public void splitterStop() EeDK ^W8N
{ gT#hF]c:
bStop = true; _Eus7
} xi}3)5
OY,iz
|*JMCI@Mz
} GEJy?$9
d6zfP1lQ
G%XjDxo$I
/* !BEl6h
**FileAccess.java ftccga
*//文件访问(定位，写) OYj~"-3y)
package NetFox; _.+2sm
import java.io.*; Wq"^{
,A;wLI
nRh.;G
public class FileAccessI implements Serializable{ q4]Qvf>
fT0+inRG
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C o,"
RandomAccessFile oSavedFile; >{.|Ng4K
long nPos; Fh~ pB>t
L%31>)8
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public FileAccessI() throws IOException H57wzG{xG
{ Xo ,U$zE
this("",0); nrJW.F]S8[
} s/0~!0
8=WX`*-uH
(dQsR sA
public FileAccessI(String sName,long nPos) throws IOException ]<:qMLg
{ _g%h:G&^
oSavedFile = new RandomAccessFile(sName,"rw"); hZUnNQ
this.nPos = nPos; 6a4-VX5
oSavedFile.seek(nPos); @0fiui_
} Fg^Z g\X3
3<X*wVi)NN
4&wwmAp^
public synchronized int write(byte[] b,int nStart,int nLen) g%%j"Cz1
{ f6JC>Np
int n = -1; k'PNfx\K
try{ `c/mmS
oSavedFile.write(b,nStart,nLen); fB`7f $[
n = nLen; o>@9[F,h+
} U%l<48@8
catch(IOException e) RZTC+ylj
{ i1DJ0xC]
e.printStackTrace (); A?ij
} \ 3FOI
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u8b^DB#+W
return n; Bw4 _hlm
} 'WcP+4c
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V[avV*;3i
} *7^w}v+.
4j}uVGi{e
?vV&tqnx%
/* ^8{:RiN6e~
**SiteInfoBean.java i~uoK7o|G
*/ ]=jpqxlx
package NetFox; OG{vap)
D0 ,t,,L
2F|06E'
public class SiteInfoBean { q#*b4q {
!z|a+{
k?qd -_sC
private String sSiteURL; //Site's URL T}y@ a^#
private String sFilePath; //Saved File's Path {O (@}
private String sFileName; //Saved File's Name ["SD'
private int nSplitter; //Count of Splited Downloading File 0)E`6s#M
<S(`e/#[
7(]M`bBH
public SiteInfoBean() H@V+Q}
{//nSplitter的缺省值为5 T56%3i
//default value of nSplitter is 5 #6F/:j;
this("","","",5); Qcs>BOV~
} *S] K@g
N)o/}@]6
qZ rv2dT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IT0 [;eqR
{ \4"01:u'
sSiteURL= sURL; mH5[(?
sFilePath = sPath; 95b65f
sFileName = sName; SZL('x,"^
this.nSplitter = nSpiltter; mFW/xZwR,5
?b3({P
QRAw#
} >SaT?k1E
n}toUqUnk\
,,CheRO
public String getSSiteURL() &b!|Y
{ B|.8+Q
return sSiteURL; =`KV),\
} 3p#BEH<re
iw0|A
~#nbD-*#
public void setSSiteURL(String value) uJu#Vr:m
{ MT(G=r8
sSiteURL = value; 7MhN>a;A\
} y)0wM~E;2
MfK}DEJK,
{p)=#Jd`.P
public String getSFilePath() 2y@y<38
{ N]7#Q.(~
return sFilePath; 0uwe,;
} Y0ouLUlI
\p{$9e;8yT
^>tqg^
public void setSFilePath(String value) o.x<h";
{ :%kJ9zW
sFilePath = value; @zAav>
} 6qq{JbK
3W.5[;}
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public String getSFileName() Q|i`s=|
{ O&ZVu>`g
return sFileName; Yo a|.2f
} jp viX#\S_
*$EcP`K$
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public void setSFileName(String value) X+;{&Efrl
{ k(%h{0'
sFileName = value; w;8VD`>[|
} M;zJ1
~Lf>/w
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public int getNSplitter() !Ng~;2GoA
{ HYWKx><
return nSplitter; v+qHH8
} +?R!
=b[q<p\
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public void setNSplitter(int nCount) VFjNrngl
{ ZZ@1l
nSplitter = nCount; |8s45g>
} \o=YsJ8U
} 8CN~o|uN
#Ss lH
*hZ{>
/* 3tAX4DnYrq
**Utility.java MaQ`7U5 |e
*/ v''F\V )
package NetFox; /FW{>N1
U5pg<xI
G'0]m-)dw
public class Utility { #Y;tobB
?VP07 dQTe
H;=++Dh
public Utility() RY9h^q*
{ N9jSiRJ
aK4ZH}XHE"
``9`Xq
} =BNS3W6
[7*$Sd
//线程睡眠 4E~!$Ustx
public static void sleep(int nSecond) 04wO9L;
{ 1 wB2:o<
try{ HA W57N
Thread.sleep(nSecond); xXn2M*g
} P K9BowlW
catch(Exception e) Ki{]5Rz
{ <QZ X""
e.printStackTrace (); PS3%V_2
} ?84B0K2Ns
} $TR#-q
V-.Nc#
//日志 BjsF5~+\
public static void log(String sMsg) jpI=B
{ wrmbOT
System.err.println(sMsg); $(JB"%S8c
} 9m:G8j'
t!JD]j>q
(TQhO$,
public static void log(int sMsg) C#Y_La
{ u~VvGLFf5,
System.err.println(sMsg); c"x-_Uk
} ];VJ54
} "Oj2B|:s&
6-vQQ-\
- BE.a<
/* &ytnoj1L(
**TestMethod.java =%IBl]Z!"
*/ cc_v4d{x
package NetFox; gHe%N?'
QGI_aU
E,g5[s@
public class TestMethod { r"aJ&~8::W
\$%q<_l
u/g4s (a
public TestMethod() }8,[B50
{ ///xx/weblogic60b2_win.exe |E=8
try{ TU(w>v
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g9K7_T #W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 01;
SiteFileFetch fileFetch = new SiteFileFetch(bean); iD-,C`
fileFetch.start(); uiEAi
} 6}xFE]Df-Y
catch(Exception e){e.printStackTrace ();} ^geC?m
}:f \!b
;S_\- ]m&g
} =n73bm
~!A*@aC
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public static void main(String[] args) ;4] sP^+
{ k~+(X|!5w
new TestMethod(); }'.k
} nm.~~h+8M
} h..D1(M
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