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)); &0='z
} Pgp`g.$<
for(int i=0;i<nEndPos.length-1;i++) HLYTt)f}
{ \ O#6H5F
nEndPos = nStartPos[i+1]; 6|O2i j-J
} ;vDjd2@
nEndPos[nEndPos.length-1] = nFileLength; i4XE26B;e
} 4EZl (v"f`
} )8rN
A/%+AH(
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//启动子线程 0M=U>g)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M'"@l$[QM
for(int i=0;i<nStartPos.length;i++) BnL[C:|
{ S.#IC lV
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), km(Mv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZI0C%c.~
nStartPos,nEndPos,i); t;?TXAA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f L}3I(VK
fileSplitterFetch.start(); 42Vz6 k:
} <.HDv:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q|N/vkqPz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !jIpgs5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pFZ2(b&
nEndPos = " + nFileLength); 2Y`C\u
// fileSplitterFetch[nPos.length-1].start(); @0mR_\u\
c2aW4TX2
.-[d6Pnw
//等待子线程结束 i3s,C;7[2
//int count = 0; L#|,_j=9
//是否结束while循环 yl#(jb[?1
boolean breakWhile = false; o_K. +^$
Z|h&Zd1z
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while(!bStop) e9 `n@
{ 1lJY=`8qa
write_nPos(); M2.Pf s
Utility.sleep(500); 3,QsB<9Is
breakWhile = true; {r$n $
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X9YYUnR2
for(int i=0;i<nStartPos.length;i++) $<~o,e-4
{ oOU?6nq
if(!fileSplitterFetch.bDownOver) _eE hIQ9
{ {);S6F$[3
breakWhile = false; J!5>8I(_wX
break; 8)1k>=
} ^Iz(V2
} V\ 7O)g
if(breakWhile) ;Rz+4<
break; ZMI!Sl
etPb^&#$
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//count++; J=*X%^jX9Z
//if(count>4) <H,q( :pM
// siteStop(); PS13h_j
} _2wU(XYH
6;:s N8M+1
xjplJ'jB
System.err.println("文件下载结束！"); m-M.F9R
} nisW<Q`uB
catch(Exception e){e.printStackTrace ();} %pR:.u|
} dCF!.
POl[]ni=>
|Zn|?#F
//获得文件长度 C|@6rr9TA
public long getFileSize() "8'aZ.P
{ |BO!q9633V
int nFileLength = -1; ]4$t'wI.
try{ !@r1B`]j+"
URL url = new URL(siteInfoBean.getSSiteURL()); ?0{8fGM4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KXAh0A?&+
httpConnection.setRequestProperty("User-Agent","NetFox"); exnFy-
h{R>L s
[|XMR=\>
int responseCode=httpConnection.getResponseCode(); }=+J&cR
if(responseCode>=400) ?3x7_=4t@
{ (}E ] g
processErrorCode(responseCode); }AZ0BI,TI
return -2; //-2 represent access is error aMxg6\8
} ~BSIp .
;~2RWj=-
:z^VI M
String sHeader; sn4wd:b7%
@-7h}2P Q
)YB@6TiD
for(int i=1;;i++) 6eUM[C.
{ {GTOHJ2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E>bK-jG
//Utility.log(in.readLine()); M_5$y)M
sHeader=httpConnection.getHeaderFieldKey(i); #`1@4,iC
if(sHeader!=null) (4hCT*
{ W!R}eLf@
if(sHeader.equals("Content-Length")) VSW:h
{ UX?EOrfJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jj_ t0"
break; O,&nCxB]
} H\zV/1~Y
} $rb #k{
else ?8g*"&cn
break; ?l6NQ;z
} ^9{mjy0Q
} "M)kV5v%
catch(IOException e){e.printStackTrace ();} HI` q!LPv
catch(Exception e){e.printStackTrace ();} 3rF=u:r7c
ifA)Ppt<`
8BL]]gT-I
Utility.log(nFileLength); *gq~~(jH
Z'vic#
*0K@^Db-
return nFileLength; QO0#p1fom'
} q&j4PR{
<vMdfw"(
4\cJ}p}LZ{
//保存下载信息（文件指针位置） IQ${2Dpg[
private void write_nPos() Znv3h
{ |KV|x^fJ
try{ /M}jF*5N
output = new DataOutputStream(new FileOutputStream(tmpFile)); 69z,_p$@:
output.writeInt(nStartPos.length); zdL"PF
for(int i=0;i<nStartPos.length;i++) #6'x-Z_
{ &!@7+'])
// output.writeLong(nPos); q_h=O1W
output.writeLong(fileSplitterFetch.nStartPos); deRnP$u0
output.writeLong(fileSplitterFetch.nEndPos); @w%{yzr%
} b,Z\{M:f;F
output.close(); =B0#z]qu
} Gu3# y"a>
catch(IOException e){e.printStackTrace ();} &YSjwRr
catch(Exception e){e.printStackTrace ();} d".Xp4}f
} gPo3jwo$
=JqKdLH
7j9X<8*
//读取保存的下载信息（文件指针位置） 2MV!@rx
private void read_nPos() jkzC^aG
{ %^5|3l3y
try{ ;;A8TcE '
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Dd3GdG@*~
int nCount = input.readInt(); :`pgdn
nStartPos = new long[nCount]; SuO@LroxTB
nEndPos = new long[nCount]; 7$z]oVbO'
for(int i=0;i<nStartPos.length;i++) \Ax[/J2aO
{ "kS(b4^
nStartPos = input.readLong(); 8?YWE62
nEndPos = input.readLong(); U{8]TEv
} B 66-l!xa
input.close(); -f{NVX\<0
} 'Ti7}K
catch(IOException e){e.printStackTrace ();} jjT|@\-u
catch(Exception e){e.printStackTrace ();} %yVboA1
} >=T\=y
&Z.zem?n
]*M VVzF
private void processErrorCode(int nErrorCode) >ZE8EL
{ "@!B"'xg
System.err.println("Error Code : " + nErrorCode); da'7* &/
} QR.]?t;1
{JJq/[j
Y&G]M
//停止文件下载 \Q CH.~]
public void siteStop() I6jDRC0<
{ ?3I93Bt7
bStop = true; F!LVyY"w
for(int i=0;i<nStartPos.length;i++) 82EH'C
fileSplitterFetch.splitterStop(); l]bCt b%_
ogOUrJ}P
QSaJb?I
} wDL dmrB
} <9BM%
//负责部分文件的抓取 BEm~o#D
**FileSplitterFetch.java I^CKq?V?:
*/ Q>G lA
package NetFox; 1L4-hYtCj
~O;'],#Co
f&n6;N
import java.io.*; &fIx2ZM[
import java.net.*; zFR=inI
-C>q,mDJZ
iG.qMf.
public class FileSplitterFetch extends Thread { _#kjiJj*
y[pU8QSt
53i7:1[uV
String sURL; //File URL r8k.I4
long nStartPos; //File Snippet Start Position :~% zX*
long nEndPos; //File Snippet End Position }"sZ)FE
int nThreadID; //Thread's ID |X'Pa9u
boolean bDownOver = false; //Downing is over Uu<Tn#nb
boolean bStop = false; //Stop identical , :10
FileAccessI fileAccessI = null; //File Access interface Ja*k|Rz~
'K"7Tex
.5t|FJ]`$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "G(^v?x:P
{ _YT9zG
this.sURL = sURL; 1]yjhw9g
this.nStartPos = nStart; kOQq+_Y
this.nEndPos = nEnd; "F$0NYb]I
nThreadID = id; tW=,o&C=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +Vf39}8
} B?-~f^*,jG
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public void run() SU {U+
{ t$*V*gK{
while(nStartPos < nEndPos && !bStop) hPM:=@N$
{ 0Xke26ga
T VuDK
TqZ&X|G
try{ DaK2P;WP
URL url = new URL(sURL); jgkJF[t`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #Q6.r.3@x
httpConnection.setRequestProperty("User-Agent","NetFox"); ]Zj6W9]m
String sProperty = "bytes="+nStartPos+"-"; r=`]L-}V
httpConnection.setRequestProperty("RANGE",sProperty); #Fl5]> |
Utility.log(sProperty); iJr 1w&GL$
GOzV#
NY& |:F
InputStream input = httpConnection.getInputStream(); f:).wi Ld
//logResponseHead(httpConnection); v4YY6?4
<21@jdu3n,
lwhVP$q}
byte[] b = new byte[1024]; Z,? T`[4B
int nRead; --32kuF&(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f"wm]Q59
{ OFyZY@B-C~
nStartPos += fileAccessI.write(b,0,nRead); 7wm9S4+|
//if(nThreadID == 1) e@GR[0~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \N?,6;%xB
} R24ZjbKL
(ohza<X;6
Za&.sg3RG
Utility.log("Thread " + nThreadID + " is over!"); us:V\V
bDownOver = true; jW?siQO^
//nPos = fileAccessI.write (b,0,nRead); L'*P;z7<
} l$:.bwXXO
catch(Exception e){e.printStackTrace ();} h /.^iT
} 5z$>M3
} %U4w@jp
Ga%x(1U[&
,z*-93H1
//打印回应的头信息 Gz>M`M`[4
public void logResponseHead(HttpURLConnection con) l5 FM>q
{ Je5UVf3>2&
for(int i=1;;i++) \Jcj4
{ 6*cY[R|q!
String header=con.getHeaderFieldKey(i); |.s#m^"
if(header!=null) RCS91[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f a9n6uT
Utility.log(header+" : "+con.getHeaderField(header)); cITF=Ez
else :EXH8n&|
break; N~w4|q!]
} mJ>@Dh3>G
} bhIyq4N
r%QnV0L^
U;QN+fF]u
public void splitterStop() CQLh;W`Dc
{ XO=UKk+EK
bStop = true; R m{\ R
} @rTAbEk{U
"DW; 6<m
)k@+8Yfa1p
} Sb9In_* 0
$p} /&
WLb*\
/* u_5O<UP5
**FileAccess.java xyoh B#'W
*//文件访问(定位，写) Gob;dku
package NetFox; `$X|VAS2
import java.io.*; CkJU5D
xSQ0]vE
4sVr]p`
public class FileAccessI implements Serializable{ CD]2a@j{
wc-ll&0Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e|L$e0
RandomAccessFile oSavedFile; 0'DlsC/`*
long nPos; S[J=d%(
;T|y^D
"/EE$eU
public FileAccessI() throws IOException *L%i-Wg"
{ B>^5h?(lt
this("",0); +UK".
} )A`Zgg'L7D
]Tje6iF
gAx8r-` `
public FileAccessI(String sName,long nPos) throws IOException U2tsHm.O
{ h-XMr_F
oSavedFile = new RandomAccessFile(sName,"rw"); wGqQR)a
this.nPos = nPos; _t:l:x.;T
oSavedFile.seek(nPos); a=55bEn
} '.@'^80iQ
3b_tK^|'
%HRFH
public synchronized int write(byte[] b,int nStart,int nLen) >PsP y.
{ a?+Ni|+
int n = -1; !f(aWrw7e6
try{ :Rs% (Z
oSavedFile.write(b,nStart,nLen); h=q%h8
n = nLen; 2C@hjw(
} sFEkxZi<
catch(IOException e) /mB'Fn6)
{ a{lDHk`Wf
e.printStackTrace (); !lSxBr[dQ
} c=YJ:&/5&
b&$ ?.z
=A6/D
return n; `0r=ND5.
} X^tVq..0
oCLs"L-r{
3^LSK7.:
} I5"ew=x#
M y:9
CqXDz
/* -DO*,Eecv
**SiteInfoBean.java w"CcWng1
*/ ~3{C&c
package NetFox; \ B~9Ue!
zS Yh ?NB5
LhZWK^!{S
public class SiteInfoBean { /H)K_H#|;
o W)M&$oS
n'/w(o$&
private String sSiteURL; //Site's URL :!a9|Fh~
private String sFilePath; //Saved File's Path :<%q9)aPf`
private String sFileName; //Saved File's Name VV(>e@Bc4
private int nSplitter; //Count of Splited Downloading File 9o.WJ
(K$K;f$"r
GHHErXT\a
public SiteInfoBean() qYg4H|6
{//nSplitter的缺省值为5 vqLC?{i+
//default value of nSplitter is 5 WUid5e2
this("","","",5); $'f<4
} Ae,-.xJ
&bx;GG\<4
,L+tm>I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]E66'
{ A9!gww
sSiteURL= sURL; , #yE#8
sFilePath = sPath; R v9?<]
sFileName = sName; w5l:^^zF(
this.nSplitter = nSpiltter; ~U:{~z
H/_R!G8\
r}i<cyL
} %$j)?e
EXDtVa Ot
NyD[9R?
public String getSSiteURL() D4yJ:ATO&
{ 7N^9D H{`
return sSiteURL; e~r%8.Wm
} iTU8WWY<
Xj^6ZJc
G7k0P-r,0
public void setSSiteURL(String value) $Yt29AQ
{ \#5t%t
sSiteURL = value; M}4%LjD
} O6P0Am7s
+dm&XW >
9?r|Y@xh]
public String getSFilePath() ~UjFL~K}
{ I)ub='+&;
return sFilePath; e-4XNL[F
} ~R.8r-kD`
B&0^3iKFi
b .k J&c
public void setSFilePath(String value) 65VnH=
{ pez^]I
sFilePath = value; %3'4QmpR
} C #ng`7 q
S .rT5A[
kZ+nL)YQ#
public String getSFileName() ^RG6h
{ : j&M&+
return sFileName; }N5>^y
} 4NL TtK
"GP!]3t
-zg,pK$+
public void setSFileName(String value) CGIcuHp
{ $]4^ENkI
sFileName = value; ll{jE
} e#K =SV!H
H,qIHQW#
_`WbR&d2Id
public int getNSplitter() * B,D#;6
{ `G\uTCpk
return nSplitter; 9|dgmEd
} PYqx&om
4VPL -":6
@`aR*B
public void setNSplitter(int nCount) ^Sx0t
{ IpY R
nSplitter = nCount; g^(wZ$NH
} 9iWDEk
} $j^Jj
goi.'8M|/b
(,PO(
/* JxI}#iA
**Utility.java L,.Ae i9
*/ .MuS"R{y
package NetFox; $ud5bT{n
DW@PPvfs
y]9 3z!#Z
public class Utility { m/n_e g
dg 0`0k
z %` \p
public Utility() T%K(opISc(
{ XJsHy_6
=)m2u2c M
UiA\J
} ~%_$e/T
h@FDP#H
//线程睡眠 xh[Mmq/R
public static void sleep(int nSecond) ^ng#J\
{ zcD&xoL\H
try{ 9H?er_6Yf
Thread.sleep(nSecond); ?hvPPEJf
} j$^3
catch(Exception e) *7.!"rb8A
{ xf<D5 olZ
e.printStackTrace (); aM?Xi6 U5
} g5R2a7
} on $?c
|\2zw _o
//日志 /ZZo`
public static void log(String sMsg) >|!F.W
{ E#r6e+e1Q%
System.err.println(sMsg); tYiK#N7
} w"$CV@AJ
R6]/g
`GS!$9j
public static void log(int sMsg) 5Fm.] /
{ WM NcPHcj
System.err.println(sMsg); pj&vnX6O^
} EP&iG%(k
} 64>E|w
jDIO,XuF
\-N 4G1
/* 7}>j [
**TestMethod.java Rtw^ lo
*/ _Xd,aLoo
package NetFox; AU}e^1h
\v{tK;
Q.#@xaX'{`
public class TestMethod { u_s
7kO5hlKeo
-}1S6dzr
public TestMethod() ;$l!mv7
{ ///xx/weblogic60b2_win.exe L=3^A'|
try{ @26H;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AZt~ \qf
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `o yz"07m
SiteFileFetch fileFetch = new SiteFileFetch(bean); ct=|y(_
fileFetch.start(); 7(^<Z5@
} G!T)V2y
catch(Exception e){e.printStackTrace ();} zg2A$Fd[j
Oyhl*`-*t
[>::@[
} _aL:XKM
|;ycEB1
:XcU@m
public static void main(String[] args) 9d^o2Yo
{ #ebT$hf30
new TestMethod(); @FIR9XJ
} ug0[*#|Y
} T!eeMsI
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