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)); uWs5+
} >EQd;Af
for(int i=0;i<nEndPos.length-1;i++) @lo6?9oNo
{ 9mdp\A
nEndPos = nStartPos[i+1]; h?f)Bt}ry
} vWbf5?
nEndPos[nEndPos.length-1] = nFileLength; ^a=,,6T
} FX+;azE7
} 5v51:g>c
![ & go
bERYC|
//启动子线程 $S~e"ca1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jD@KG
for(int i=0;i<nStartPos.length;i++) JTH8vk:@
{ y#[PQT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), obUX7N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), i3T]<&+j5
nStartPos,nEndPos,i); dW3q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1aC?*,e?
fileSplitterFetch.start(); zLQplw`#
} F<'@T,LVc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sq6|J])GgU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "xS?#^a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m791w8Vr
nEndPos = " + nFileLength); Hu"?wZj
// fileSplitterFetch[nPos.length-1].start(); 2Z3c`/k
_7?LINF9
/UGH7srx
//等待子线程结束 Pb05>J3N
//int count = 0; fD8A+aA
//是否结束while循环 `mU'{
boolean breakWhile = false; #!,tId
oM`[&m.,
s`2Hf&%aZJ
while(!bStop) dpHK~n j\_
{ W~ 6ii\
write_nPos(); MV"aO@
Utility.sleep(500); HtWuZq;w
breakWhile = true; n:c)R8X]
a8K"Z-LlQ
bAIo5lr
for(int i=0;i<nStartPos.length;i++) +" 4E:9P?
{ }gY:VDW
if(!fileSplitterFetch.bDownOver) !oTF2Q+C
{ 9p ;)s
breakWhile = false; S^}@X?v
break; $<jI<vD+:
} @+LZSd+I
} k@qn'Zi
if(breakWhile) L&td4`2y
break; ]|cL+|':y
!(=bH"P
b[<Q_7~2
//count++; j(Tt-a("z
//if(count>4) pVTx#rY
// siteStop(); ;\yVwur
} $i@~$m7d-
s'yA^ VPf
$xT'cl/IH
System.err.println("文件下载结束！"); !"\UT&
} LD]>_P83
catch(Exception e){e.printStackTrace ();} 4u;db_gX
} sWp]Zy
\TM%,RC3K
\hSOJ,{)U
//获得文件长度 ~2Jvb[IM
public long getFileSize() p"Ki$.Y
{ ]HoQ6R\E b
int nFileLength = -1; o g.LD7&/
try{ Fwn4c4-%
URL url = new URL(siteInfoBean.getSSiteURL()); wpw~[xd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SOo/~giz|
httpConnection.setRequestProperty("User-Agent","NetFox"); C!N&uNp@s
f]F]wg\_f
{5}UP@h
int responseCode=httpConnection.getResponseCode(); n,eO6X 4
if(responseCode>=400) 0*?~I;.2m$
{ sMh3IL9(*
processErrorCode(responseCode); v@bs4E46e
return -2; //-2 represent access is error Ql-RbM
} ^Xjh?+WM
R3;GMe@D#
7[)4k7
String sHeader; ,}%+5yH
2lw0'
(r_xs
for(int i=1;;i++) ,]e!OZ[$m
{ /M>8ad
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); M~Tq'>Fn
//Utility.log(in.readLine()); <'H^}gQow
sHeader=httpConnection.getHeaderFieldKey(i); #&vP(4p
if(sHeader!=null) _iBNy
{ i>gbT+*E!
if(sHeader.equals("Content-Length")) GJW>8*&&(
{ :5?g<@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >U@7xeK
break; A@^e4\
} /I~iUND"G
} @A(*&PU>j
else 56(S[
break; XBv:$F.>$
} 8/Z
} Nq>74q]}n8
catch(IOException e){e.printStackTrace ();} Ct[{>asun
catch(Exception e){e.printStackTrace ();} ^S*~<0NQ'
aNgaV$|2a
L1#z'<IO
Utility.log(nFileLength); ws:@Pe4AF
|}paa
FVkb9(WW
return nFileLength; IDbqhZp(
} Y*iYr2?;
l v]TE"
f,Vj8@p)x
//保存下载信息（文件指针位置） Tvr2K84l
private void write_nPos() {f]K3V
{ R.Xh&@f`
try{ X 10(oT
output = new DataOutputStream(new FileOutputStream(tmpFile)); dwOB)B@{H
output.writeInt(nStartPos.length); A=q)kcuy5
for(int i=0;i<nStartPos.length;i++) [@MV[$W5
{ yLFc?{~7
// output.writeLong(nPos); ]dB6--
output.writeLong(fileSplitterFetch.nStartPos); [pf78
output.writeLong(fileSplitterFetch.nEndPos); HJT}v/FZ
} 7r#U^d(
output.close(); -AcLh0pc
} ^`NU:"
catch(IOException e){e.printStackTrace ();} }=Yvs)
catch(Exception e){e.printStackTrace ();} E/@w6uIK[
} C5;=!B
.]`LR@qf
7a.$tT
//读取保存的下载信息（文件指针位置） >h>X/a(=~
private void read_nPos() !kZ9Ox9^
{ 3# G;uWN-
try{ a[iuE`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ur^)bp<n
int nCount = input.readInt(); 8/X#thG
nStartPos = new long[nCount]; w=>~pYASH
nEndPos = new long[nCount]; T-pes1Wu
for(int i=0;i<nStartPos.length;i++) v5U\E`)s
{ dD@k{5
nStartPos = input.readLong(); *Q=ER
nEndPos = input.readLong(); U%3d_"{;
} [80jG+6
input.close(); 9dl\`zlA*
} iD=VNf
catch(IOException e){e.printStackTrace ();} lNuZg9h
catch(Exception e){e.printStackTrace ();} *Iv.W7 [
} Gv(bD6Rz
Gqvnc8V&
|FS,Av
private void processErrorCode(int nErrorCode) wb^Yg9
{ !\wdX7%
System.err.println("Error Code : " + nErrorCode); Oz{.>Pjn^o
} (6i)m c(
M^I*;{w6i
J+IQvOn_|
//停止文件下载 46c7f*1l
public void siteStop() ,@"Z!?e
{ =qH9<,p`H
bStop = true; %KL"f
for(int i=0;i<nStartPos.length;i++) y&T(^EA;
fileSplitterFetch.splitterStop(); `pS<v.L3
c%-s_8zvi
y\L$8BSL
} Nx>WOb98
} >&V?1!N"
//负责部分文件的抓取 4/; X-
**FileSplitterFetch.java \ZiZX$
*/ `C 'WSr
package NetFox; !l!^`c
(.TkvUj`
-#srn1A>
import java.io.*; [V'3/#Z
import java.net.*; tpw0j CVu
&>kklP
#;GIvfW
public class FileSplitterFetch extends Thread { /rp.H'hC
Gxk=]5<7
.U|e#t
String sURL; //File URL V {R<R2h1
long nStartPos; //File Snippet Start Position g _fvbVX
long nEndPos; //File Snippet End Position xo#&&/6
int nThreadID; //Thread's ID D6&fDhO27
boolean bDownOver = false; //Downing is over .ruGS.nS4
boolean bStop = false; //Stop identical /5M@>A^?'
FileAccessI fileAccessI = null; //File Access interface 9An_zrJ%i
fRKO> /OT
GFd~..$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -AwR$<q'
{ @@$=MSN
this.sURL = sURL; Rt!G:hy7
this.nStartPos = nStart; -N`j` zb|
this.nEndPos = nEnd; u,<I%
nThreadID = id; {6Tw+/`P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X51pRP $R
} 7MIu-x|
!%b.k6%>w
Pe@M_ r
public void run() Qd"{2>
{ m[&]#K6
while(nStartPos < nEndPos && !bStop) G4g<PFx
{ K%9PIqK?4
AnVj '3
jG=*\lK6
try{ .&d]7@!qy
URL url = new URL(sURL); |@pJ]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gs$<r~Tg
httpConnection.setRequestProperty("User-Agent","NetFox"); mlCw(i,
String sProperty = "bytes="+nStartPos+"-"; 5P_%Vp`B2
httpConnection.setRequestProperty("RANGE",sProperty); cF{5[?wS
Utility.log(sProperty); xzF@v>2S+
hl}@ha4'
.QX|:]|n
InputStream input = httpConnection.getInputStream(); =&?}qa(P
//logResponseHead(httpConnection); <-uE pF
v|acKux=t
'/+l\.z"&
byte[] b = new byte[1024]; 4~-"k{Xt
int nRead; b}'XDw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Qj(q)!Ku
{ .um]1_= \
nStartPos += fileAccessI.write(b,0,nRead); dA-ik
//if(nThreadID == 1) <V)T_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R?3^Kx
} ^SnGcr|a'
0] e=
3XY;g{`=q
Utility.log("Thread " + nThreadID + " is over!"); n,sl|hv2U
bDownOver = true; )qs>Z?7
//nPos = fileAccessI.write (b,0,nRead); X~XpX7d!
} 4"72
catch(Exception e){e.printStackTrace ();} *=i|E7Irg
} 7m0sF<P{g
} YGrmco?G
+ 5E6|
%.,-dV'
//打印回应的头信息 J^[>F{8!n
public void logResponseHead(HttpURLConnection con) QUd`({/@:
{ ]5IG00`
for(int i=1;;i++) tU7,nE>p
{ Rb=T'x'
String header=con.getHeaderFieldKey(i); VD+TJ` r
if(header!=null) FNlzpCT~L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6LZ(bP'd;
Utility.log(header+" : "+con.getHeaderField(header)); ]CyWL6z
else ^sIxR*C[v
break; {M:Fsay>p
} cl4`FU
} 5]cmDk
[?uiM^&
,Zs:e.
public void splitterStop() GKdQ
{ OI;0dS
bStop = true; yQb^]|XG
} v3 4!rL
7eb^^a?
%g7 !4
} 9`4mvK/@
z7'3d7r?
y BF3Lms
/* mmP>Ji
**FileAccess.java /CX_@%m}e=
*//文件访问(定位，写) '6i"pJ0%
package NetFox; .Ymoh>JRL
import java.io.*; 5D0O.v
`Q?rQ3A}
TJ9JIxnS
public class FileAccessI implements Serializable{ uPbvN[~t
Ut4cli&cC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 VS0 &[bl
RandomAccessFile oSavedFile; l6ayV
long nPos; NT?Gl(
7J$
GkqKIs
public FileAccessI() throws IOException 9:zW$Gt&
{ |x*~PXb
this("",0); ` MIZqHM @
} SSOF\
\{
;&4}hPq
public FileAccessI(String sName,long nPos) throws IOException 'Ba Ba=
{ $/</J]2`;
oSavedFile = new RandomAccessFile(sName,"rw"); FbB^$ ]*
this.nPos = nPos; h-u63b1"?
oSavedFile.seek(nPos); m~"<k d
} ?)<DEu:Y
^(7<L<H
!4zSE,1
public synchronized int write(byte[] b,int nStart,int nLen) Dz$GPA
{ U{(B)dFTH
int n = -1; $%9.qy\8
try{ EJ7}h?a]U_
oSavedFile.write(b,nStart,nLen); ^g/
n = nLen; 4'JuK{/ A7
} _bB:1l?V
catch(IOException e) [5>f{L!<T<
{ `tKrTq>
e.printStackTrace (); )P
} Z{"/Ae5]
=\]5C
A*tG[)
return n; %9ef[,WT
} KEF"`VTB@
^hPREbD+f
"&(.Z(
} S*,DX~vig
BUR96YN.
?B> {rj
/* )U0`?kD
**SiteInfoBean.java TtA6N8G
*/ \FOoIY!.x
package NetFox; K(P24Z\#
-0[?6.(s"
yn=BO`sgW
public class SiteInfoBean { @jb -u S
pC<~\RR
1FC'DH!
private String sSiteURL; //Site's URL A/eZnsk
private String sFilePath; //Saved File's Path 07pASZ;~
private String sFileName; //Saved File's Name ( <~
private int nSplitter; //Count of Splited Downloading File )/VhkSXbG!
67Z@Hg
5~GHAi
public SiteInfoBean() #6O<!{PH6
{//nSplitter的缺省值为5 1#rcxUSi
//default value of nSplitter is 5 .bcoH
this("","","",5); Y*0AS|r!
} +o+e*B7Eh
NN(ZH73
t5 :4'%|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8w-2Q
{ c:QZ(8d]L
sSiteURL= sURL; i*-[-hn-V
sFilePath = sPath; ~,j52obR6Z
sFileName = sName; T](N ^P
this.nSplitter = nSpiltter; }6zo1"
G Y??q8
hRK&
} g}(yq:D
V`*N2ztSL
AAbI+L0m{
public String getSSiteURL() (`C#Tq
{ PuyJ:#a
return sSiteURL; ko-|hBNv
} Mf'T\^-!
Wp7lDx
2>%|PQ
public void setSSiteURL(String value) @ol}~&"
{ S0-f_,(
sSiteURL = value; }4'5R
} 8%C7!l q
S#km`N`
c8uFLM j
public String getSFilePath() 7 YS'Tf
{ J+hiz3N
return sFilePath; 04;E^,V
} 4yOYw*X
S$O+p&!X
l|WdJn o
public void setSFilePath(String value) m/ D~D~
{ <%d/"XNg[D
sFilePath = value; |"}F cS y
} Vf28R,~m
MR")
rw:z|-r
public String getSFileName() N{/):O
{ zVEG) Hr
return sFileName; T'VZ=l[
} &6ymGo
n1yIQ8F
Dnx` !
public void setSFileName(String value) ?w^MnK0U)
{ c?ZM<Y"
sFileName = value; AkMP)\Q
} }57s
aCxF{>n
,"6Bw|s
public int getNSplitter() & OO0v*@{
{ g=G>4Ua3
return nSplitter; .DX
} m5c=h
OKW}8qM
z@za9U`6i
public void setNSplitter(int nCount) nZtMF%j'
{ e3o?=;
nSplitter = nCount; *A<vrkHz
} \zCw&#D0Z
} _E\Cm
V{A_\
E`0mn7.t
/* gc<w nm|
**Utility.java Z;v5L/;
*/ '{>R-}o[3
package NetFox; 7~zd % o
|B{@noGX
fBj-R~;0
public class Utility { %P8*Az&]T
,J*C'#sW
l& A8P
public Utility() nYFM^56>_
{ `jHbA#sO
}}?,({T|n
zf4\V F
} /Z~}dWI
b((>?=hh
//线程睡眠 Jn:h;|9w
public static void sleep(int nSecond) S4ys)!V1V
{ T]_]{%z
try{ "26=@Q^Y
Thread.sleep(nSecond); R$|"eb5
} 5&C:&=Y
catch(Exception e) C%RYQpY*c
{ C@o8C%o
e.printStackTrace (); ^-^ii3G`
} !VDNqW
} \rpXG9
;2y4^
//日志 =&K8~
public static void log(String sMsg) iNCT(N~.
{ f>CJ1;][{
System.err.println(sMsg); BjSd\Ul
} {D$5M/$
/:Q
<jAn~=Uq[,
public static void log(int sMsg) 4 (c{%%
{ m[}@\y
System.err.println(sMsg); -F$v`|(O+
} M\_IQj
} Fp&tJ]=B.
VbI$#;:[7
|Cm6RH$(
/* o#K*-jOfiH
**TestMethod.java \[9^,QP
*/ # 4&t09
package NetFox; \1ncr4
J?9n4 u
(Q?@LzCjy
public class TestMethod { y*#YIS56I
71+ bn
|!q,J
public TestMethod() elGwS\sw
{ ///xx/weblogic60b2_win.exe -=WQed}
try{ s-801JpiJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^wIg|Gc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Zmc"
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3\ {?L
fileFetch.start(); O=5q<7PM.
} J kxsua
catch(Exception e){e.printStackTrace ();} /O}lSXo6E
XiMd|D
at+Nd K
} ]iYO}JuX
o~{rZ~
' ~1/*F%8
public static void main(String[] args) nv<t$r
{ A2.GNk
new TestMethod(); ~s{ V!)0
} Q~f mVWq
} Ge`PVwn
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