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)); r/v'h@
} O@JgVdgf
for(int i=0;i<nEndPos.length-1;i++) #oRm-yDr
{ $YZsaw
nEndPos = nStartPos[i+1]; Ow7NOhw
} K&FGTS,
nEndPos[nEndPos.length-1] = nFileLength; C!Cg.^;
} bwh7.lDAl
} QZy+`
v|5:;,I
s( @w1tS.
//启动子线程 $=dp)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @L^Fz$Sx
for(int i=0;i<nStartPos.length;i++) DxjD/?R8
{ u@|izRk
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y.I-hl1<r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wMy$T<:
nStartPos,nEndPos,i); a<X8l^Ln
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &gJKJ=7
fileSplitterFetch.start(); Pn@k)g
} [8*Ovd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8r '
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (]7*Kq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mv@cGdxu
nEndPos = " + nFileLength); p:M#F:
// fileSplitterFetch[nPos.length-1].start(); CU=}]Y
`@GqD
RZ)sCR
//等待子线程结束 K/RQ-xd4
//int count = 0; /CpUq;^
//是否结束while循环 "8K>Yu17
boolean breakWhile = false; W-wy<<~f
Q(SVJ
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while(!bStop) "bZV<;y6
{ wUzQ`h2
write_nPos(); qh Ezv~
Utility.sleep(500); U$a Eby.
breakWhile = true; o?\)!_Z|
\~xI#S@
{#q']YDe`
for(int i=0;i<nStartPos.length;i++) lhg3 }dW
{ ^_4TDC~h
if(!fileSplitterFetch.bDownOver) jB }O6u[%
{ j`^':!
breakWhile = false; H"(:6 `
break; d7N;Fa3yL
} 8?] :>
} eydVWVN
if(breakWhile) WtI1h`Fo
break; C%d 4ItB >
2&91C[da0
PpMZ-f@
//count++; tb,.f3;
//if(count>4) .lu:S;JSnS
// siteStop(); mY-Z$8r
} ^B@4 w\t
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|Y3!Lix
System.err.println("文件下载结束！"); Okk[}G)
} {frEVHw
catch(Exception e){e.printStackTrace ();} 9[DQ[bL
} 5_Yv>tx
sBuJK'
2>Kq)Ii
//获得文件长度 a:@9GmtV&
public long getFileSize() Bp\io$(%
{ FW7+!A&F
int nFileLength = -1; [rqe;00]
try{ c5P52_@
URL url = new URL(siteInfoBean.getSSiteURL()); kFv\V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l^xkXj
httpConnection.setRequestProperty("User-Agent","NetFox"); %Hv$PsSJ
T\c;Ra
nzy =0Ox[
int responseCode=httpConnection.getResponseCode(); m6V1m0M
if(responseCode>=400) T~$ePVk>L
{ :w_F<2d0 0
processErrorCode(responseCode); 6bnAVTL5
return -2; //-2 represent access is error v,vTRrpK
} B0=:A
f[7'kv5S
4 E3@O
String sHeader; ^a; V-US
;0E"4(S.q1
=D5@PHpv(
for(int i=1;;i++) <6/XE@"
{ $Br^c< y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); d1e'!y}R5
//Utility.log(in.readLine()); Z.6`O1OY}?
sHeader=httpConnection.getHeaderFieldKey(i); zq!2);,
if(sHeader!=null) P},S[GaZ
{ Qm`f5-d
if(sHeader.equals("Content-Length")) JoW*)3Z
{ >&^w\"'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xHsH .f_{
break; Y@eHp-[
} |+6Z+-.Hg
} 3JW9G04.
else t{~"vD9Am
break; BT>*xZLpS
} ^'EEry
} 344,mnAd
catch(IOException e){e.printStackTrace ();} ?;)(O2p
catch(Exception e){e.printStackTrace ();} 8YkP57Y%[Z
'IfM~9'D
(i*1M
Utility.log(nFileLength); 6FEtq,;0w
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3kR- WgVF,
return nFileLength; N)poe2[
} :NbD^h)R
[-6j4D
GsDSJz
//保存下载信息（文件指针位置） AX'(xb,
private void write_nPos() R$6Y\ *L[
{ /SMp`Q88
try{ ~fCD#D2KU
output = new DataOutputStream(new FileOutputStream(tmpFile)); *otJtEI>6
output.writeInt(nStartPos.length); 0@AK
for(int i=0;i<nStartPos.length;i++) K:'pK1zy
{ ?\vJ8H[bD
// output.writeLong(nPos); 9HTb
output.writeLong(fileSplitterFetch.nStartPos); NmB0CbB
output.writeLong(fileSplitterFetch.nEndPos); Y}1|/6eJ
} U7PA%
output.close(); B/5CjHz
} 9!9 Gpi
catch(IOException e){e.printStackTrace ();} qsJA|z&6x
catch(Exception e){e.printStackTrace ();} [j93Mp
} P45q}v
dDpe$N
:hMuxHr
//读取保存的下载信息（文件指针位置） $oxPmELtpe
private void read_nPos() W;KHLHp-
{ R1P,0Yf
try{ !5A nr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4uNcp0
int nCount = input.readInt(); <EBp X
nStartPos = new long[nCount]; PI{sO |
nEndPos = new long[nCount]; h+Q==
for(int i=0;i<nStartPos.length;i++) d9Q%GG0]
{ Pi8U}lG;
nStartPos = input.readLong(); R8],}6,;E}
nEndPos = input.readLong(); 'kh%^_FH7
} L3<XWpv
input.close(); JWn9&WK
} m7RWuI,
catch(IOException e){e.printStackTrace ();} Hfc^<q4a.
catch(Exception e){e.printStackTrace ();} gcv,]v8
} C62<pLJf
@#T?SNIL5
nmSpNkJ5
private void processErrorCode(int nErrorCode) dUe"qH29s
{ U3za}3
System.err.println("Error Code : " + nErrorCode); 8"<!8Img
} '6xn!dK
o_5|L9
Vm6^'1CY
//停止文件下载 hVGakp9WE
public void siteStop() ~Yr.0i.W
{ \DQ;v
bStop = true; xE)pj|
for(int i=0;i<nStartPos.length;i++) _X]?
fileSplitterFetch.splitterStop(); <=7p~ i5
{;-$;\D
+QHhAA$
} R 7{rY
} ZR#UoYjupb
//负责部分文件的抓取 V!Joh5=a
**FileSplitterFetch.java zc2,Mn2
*/ I+<`}
package NetFox; D^TKv;%d
ZO;]Zt]
k[zf`x^
import java.io.*; >)5vsqGZaK
import java.net.*; snK9']WXo
aSK$#Xeu
my} P\r.
public class FileSplitterFetch extends Thread { )8k6GO8|
"Km`B1f`
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String sURL; //File URL @+2Zt%
long nStartPos; //File Snippet Start Position u(~s$ENl
long nEndPos; //File Snippet End Position LSfj7j`
int nThreadID; //Thread's ID jxoEOEA
boolean bDownOver = false; //Downing is over q OXL(
boolean bStop = false; //Stop identical g_x<+3a
FileAccessI fileAccessI = null; //File Access interface stDn{x.
<B fwR$
FE5R ^W#u-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~Ep&:c4:D
{ +amvQ];?Q8
this.sURL = sURL; r'!l` gm,S
this.nStartPos = nStart; 3gM{lS}h#
this.nEndPos = nEnd; m:^@AR1%d
nThreadID = id; 81n%2G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =DCQ!02
} dqkkA/1
l-Xxv
IX>|bA;
public void run() k]JLk"K
{ Q\rqG
while(nStartPos < nEndPos && !bStop) i3~!ofTb
{ t"L:3<U7
pQ/:*cd+M
L"Gi~:z
try{ F;ZLoG*U
URL url = new URL(sURL); fg9sZ%67]\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0N}5sF
httpConnection.setRequestProperty("User-Agent","NetFox"); m=K XMX
String sProperty = "bytes="+nStartPos+"-"; .dfTv/n
httpConnection.setRequestProperty("RANGE",sProperty); ::R^ w"
Utility.log(sProperty); z~BB|-kp1
>hhd9
Cse0!7_T
InputStream input = httpConnection.getInputStream(); !Q#b4f
//logResponseHead(httpConnection); :X!(^a;]
-`RJk(
SN+Bmdup
byte[] b = new byte[1024]; zPmVECS
int nRead; A/QVotcU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Za} |Ee
{ 4/jY;YN,2
nStartPos += fileAccessI.write(b,0,nRead); 70NHU;&N
//if(nThreadID == 1) 08f~vw"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^AM_A>HnG
} q!,do2T
*HC8kD a%$
wx!*fy4hL
Utility.log("Thread " + nThreadID + " is over!"); 9t[278B6
bDownOver = true; \(CW?9)
//nPos = fileAccessI.write (b,0,nRead); y((_V%F}
} y"hM6JI
catch(Exception e){e.printStackTrace ();} J'EK5=H
} EH3G|3^xz
} W>~%6K>p
@b/2'
[vi4,'wm
//打印回应的头信息 KFhn}C3 i
public void logResponseHead(HttpURLConnection con) GlZ9k-ZRF
{ hK"=~\,
for(int i=1;;i++) KCu6:)6'
{ q+z\Y?
String header=con.getHeaderFieldKey(i); ""+*Gn7^8
if(header!=null) Fs|;>Up0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ob7_dWAG
Utility.log(header+" : "+con.getHeaderField(header)); >(rB[ZJ
else iK]g3ew|
break; VB\6SG
} D5>~'N3b
} 8_m9CQ6 i
HH#i.s2
jq]"6/xxb
public void splitterStop() _PbfFY #
{ hn|E<
bStop = true; 0%F.]+6[O4
} ;5k|gW
@,&m`qzd+
% 4"~O _S
} Z ~9N
|w2AB7EU
0_ \ g
/* \,!q[nC
**FileAccess.java P` F'Nf2U
*//文件访问(定位，写) D,j5k3< #
package NetFox; 3x0wk9lND
import java.io.*; RM1uYFs<
}hitU(5t0
Pu*HZW3l
public class FileAccessI implements Serializable{ ()#tR^T
}.) 43(>]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g<4M!gi
RandomAccessFile oSavedFile; Z{4aGp*
long nPos; "EYjY->
0r ; nz]'
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public FileAccessI() throws IOException W+ '}O<
{ zZc@;S#
this("",0); yO;C3q
} K('lH-3wS
<1+6O[>{
NND=Zxl
public FileAccessI(String sName,long nPos) throws IOException yLO &(Mb
{ >DUE8hp;<
oSavedFile = new RandomAccessFile(sName,"rw"); KBRg95E~]l
this.nPos = nPos; nl9Cdi]o
oSavedFile.seek(nPos); \seG2vw$
} 50GYL5)q
XQJ^)d00h
$:E}Nj]{&
public synchronized int write(byte[] b,int nStart,int nLen) _#D\*0J
{ N3yB1_
int n = -1; {/A)t1nL
try{ Y-3[KHD
oSavedFile.write(b,nStart,nLen); ;#yu"6{
n = nLen; c`i=(D<
} @ZkAul0@
catch(IOException e) LbX6p
{ nN`Z0?
e.printStackTrace (); EdAR<VfleA
} }\939Y
Ls>u`hG
$JhZ'Z
return n; .eabtGO,
} W-!Bl&jF[
QI#*5zm
Cj !i)-
} v*H &F
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Cl9SPz
/* :q>oD-b$}
**SiteInfoBean.java -Y8ks7
*/ Z6R: rq
package NetFox; Z<N&UFw7QJ
uspkn1-
y*}vG}e%
public class SiteInfoBean { sWsG,v_
f OM^V{)T
{\svV 0)~
private String sSiteURL; //Site's URL jom}_
private String sFilePath; //Saved File's Path Db#W/8 a8k
private String sFileName; //Saved File's Name 5y%un
private int nSplitter; //Count of Splited Downloading File :kb1}Wu
AB2mt:^
N753
public SiteInfoBean() +~w?Xw,
{//nSplitter的缺省值为5 '&-5CpDUs
//default value of nSplitter is 5 {=bg5I0|a
this("","","",5); ~KAp\!,
} Mhb '^\px
abROFI5.L
pcI&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lL(p]!K'
{ 5u;Rr 1D
sSiteURL= sURL; ?w]"~
sFilePath = sPath; sf |oNOz
sFileName = sName; &'5@azU
this.nSplitter = nSpiltter; Q7~'![(a
t7um [
2^)D .&
} SY%A"bC
/h}PEu3y
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public String getSSiteURL() je&dioZ>
{ Rk($lW)
return sSiteURL; IajD;V
} Q`.'-iq
R'Kt=.s<
)-bD2YA{
public void setSSiteURL(String value) 9W{,=.%MX$
{ 0+T*$=?
sSiteURL = value; dT5J-70Fl
} BFBR/d[&
LP.HS'M~u
![*:.CW
public String getSFilePath() E2^ KK:4s
{ BZovtm3E
return sFilePath; D:=t*2-Iv
} @GN(]t&3
9@:BK;Fi
8)L'rW{q#
public void setSFilePath(String value) @SU8\:(U
{ jCU=+b=
sFilePath = value; M{C6rm|
} $Mdbto~<
L +L9Y}
QB!jLlg(
public String getSFileName() K@B" ]6
{ r eGm>
return sFileName; b6 $,Xh
} q_cC7p6t
3\;v5D:
+ c`AE
public void setSFileName(String value) Fj S%n$
{ \ jECSV|
sFileName = value; >xT^RYS
} ,Kuk_@(}5~
N? M
m;dm|4L^
public int getNSplitter() .:rmA8U[
{ Rv98\VD"
return nSplitter; }i(qt&U;
} IE2CRBfs
_}D%iJg#
=4eUAeH {w
public void setNSplitter(int nCount) :4|M jn
{ "u_i[[y
nSplitter = nCount; <0#^7Z
} UH[<&v
} j.DHqHx
R~)ybf{
2UiR~P]%
/* `ruNA>M
**Utility.java xOythvO
*/ v,{h:
package NetFox; #b'N}2'p#V
P|N2R5(>T
9RH"d[%yc}
public class Utility { @D)Z{=>{=5
[& ^RP,N~
%#u.J
public Utility() |m)kN2w
{ 1]T|6N?
[F+,YV%t
=Q-k'=6\
} tmO`|tn&
B8H75sz
//线程睡眠 ?R|th Z
public static void sleep(int nSecond) 6W&_2a7*
{ y%S})9
try{ 7NJFWz!
Thread.sleep(nSecond); eZH~je{1
} :'}@Al9=>
catch(Exception e) _\\ -md:
{ hd2'AlB
e.printStackTrace (); *nRNg.i3D
} UX2lPgKdLz
} +6l]]*H
px=]bALU
//日志 RF?DtNuq
public static void log(String sMsg) T p<s1'"
{ d]SYP
System.err.println(sMsg); RNWX.g)b
} AOb]qc
wfR&li{
X:EEPGE
public static void log(int sMsg) )&,{?$.
{ 8AL\ST51x"
System.err.println(sMsg); }Cj8
} mrM4RoO
} [&#/|zH'j:
c?E{fD"Fc3
`)Ky0&?
/* eg<pa'Hw
**TestMethod.java I4t*?
*/ ,DQjDMjrf
package NetFox; `VT>M@i/
qf#)lyr<D6
iPj~I
public class TestMethod { C&<~f#lB
ZVih=Y-w
5l{Ts04k%
public TestMethod() S,{tV=&m]
{ ///xx/weblogic60b2_win.exe mJ5H=&Z
try{ * F4UAQzYb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6RoAl$}'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ny*i+4Mb
SiteFileFetch fileFetch = new SiteFileFetch(bean); [f/I2
fileFetch.start(); {tiKH=&J
} "_1)CDqP
catch(Exception e){e.printStackTrace ();} `]i []|
r^fe4b
[?0d~Q(R#
} E4z)Mr#
EGVM)ur
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public static void main(String[] args) K> g[k_
{ Na{Y}0=^y
new TestMethod(); neZ.`"LV
} bulS&dAX
} L%"LlSg
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