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)); Rb\\6BU0
} WzZb-F
for(int i=0;i<nEndPos.length-1;i++) 4GaF:/
{ +e4o~p
nEndPos = nStartPos[i+1]; &{"aD&
} k+%6:r,r&
nEndPos[nEndPos.length-1] = nFileLength; Au:Q4x.
} ,qt9S0QS
} p"Fj6T2
!7Ta Vx}`(
Lymy/9
//启动子线程 Rl-Sr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H}X3nl\]
for(int i=0;i<nStartPos.length;i++) 8g&uCv/Uk
{ 41,Mt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $c[8-=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HPm12&8,
nStartPos,nEndPos,i); )CEfG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hesL$Z [
fileSplitterFetch.start(); 91e&-acA
} EubF`w$KWX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I=|b3-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); G'Jsk4:c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XkOsnI8n
nEndPos = " + nFileLength); a\aJw[d{
// fileSplitterFetch[nPos.length-1].start(); b=`h""u
g!cTG-bh>J
)"wWV{k
//等待子线程结束 ojUBa/
//int count = 0; GR Rv0M
//是否结束while循环 9UZKL@KC
boolean breakWhile = false; 3<CCC+47
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!A,]
while(!bStop) 5fA<I _ D
{ $62!R]C9\
write_nPos(); =gw'MA
Utility.sleep(500); m "h{HgJd
breakWhile = true; "i(k8+iK
-:dUD1
j0~]o})@i
for(int i=0;i<nStartPos.length;i++) 8:|F'{<<b
{ 7q^osOj"
if(!fileSplitterFetch.bDownOver) a4Fe MCvV9
{ :4;ZO~eq!
breakWhile = false; a2SMNC]
break; #Huvn4x
} /Z94<}C6b
} ]ECzb/
if(breakWhile) R6r'[-B2
break; Ux2(Oph
Q &<:W4N*
J 6D?$
//count++; x$tx!%,)/S
//if(count>4) =c"`>Vi@d
// siteStop(); D .oX>L#:
} #HfvY}[o
?~Fk_#jz,@
g[!t@K
System.err.println("文件下载结束！"); N0,wT6.
} DpI)qg#>V
catch(Exception e){e.printStackTrace ();} 0GK<l
} ) wtVFG
KuL2X@)}
BqC!78Y/e
//获得文件长度 <C`qJP-
public long getFileSize() AKk6kI8F
{ $vlq]6V8
int nFileLength = -1; -,C">T%\
try{ jCa%(2~iQ7
URL url = new URL(siteInfoBean.getSSiteURL()); /g BB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }OZp[V
httpConnection.setRequestProperty("User-Agent","NetFox"); [p^N].K$
.&:y+Oww~
U` uP^
int responseCode=httpConnection.getResponseCode(); >~8;H x].d
if(responseCode>=400) `$vTGkGpY
{ [DpGL/Y.
processErrorCode(responseCode); ?-1r$z
return -2; //-2 represent access is error W ZdEfY{
} e33j&:O
FR&4i" +
bw\fKZ
String sHeader; |WqEJ*$,
1BO$xq
1RpTI7
for(int i=1;;i++) `?r]OVe{y
{ eM Ym@~4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,#:*dl
//Utility.log(in.readLine()); yV[9 (
sHeader=httpConnection.getHeaderFieldKey(i); v6(Yz[
if(sHeader!=null) D!<[\G
{ $N4%I4
if(sHeader.equals("Content-Length")) =oQw?,eY
{ A(zF[\{]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Yt*2/jw^
break; uTTM%-DMHT
} ^K*uP^B=
} 41Bp^R}^/
else hqrI%%
break; A[)od
} b~dm+5W7
} D#Fe\8!l
catch(IOException e){e.printStackTrace ();} )NAC9:8!
catch(Exception e){e.printStackTrace ();} AT Dm$ *
'?7th>pC
DID&fj9m
Utility.log(nFileLength); 9ZFvN*Zf'
tVVnQX
v0hr~1
return nFileLength; <q|IP_
} ]4~- z3=y
."b=dkx
2c:H0O 0o
//保存下载信息（文件指针位置） y Nb&;E7 H
private void write_nPos() JA0$Fz
{ b[p<kMTir
try{ tTrUVuZ
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZfalB
output.writeInt(nStartPos.length); \|^fG9M~
for(int i=0;i<nStartPos.length;i++) 0w^\sf%s
{ w20E]4"
// output.writeLong(nPos); @gzm4
output.writeLong(fileSplitterFetch.nStartPos); f5D.wSY
output.writeLong(fileSplitterFetch.nEndPos); 5c6CH k`:
} k<W n
output.close(); p_h)|*W{
} F jdh&9Zc
catch(IOException e){e.printStackTrace ();} eveGCV;@
catch(Exception e){e.printStackTrace ();} Ij;=
} lOp/kGmn+
2}`Q9?
Vlb L p;
//读取保存的下载信息（文件指针位置） pl62mp!
private void read_nPos() `L0aQ$'>z
{ /E>z8J$
try{ pL`snVz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q]X0O10
int nCount = input.readInt(); 7s:`]V%
nStartPos = new long[nCount]; "o#N6Qu71
nEndPos = new long[nCount]; L8-
for(int i=0;i<nStartPos.length;i++) MU5@(s3B?
{ : sIZ+3
nStartPos = input.readLong(); etF?,^)h=g
nEndPos = input.readLong(); 7O5`&Z'-
} +kCVi
input.close(); ]PdpC"
} b:fy
catch(IOException e){e.printStackTrace ();} $$YLAgO4
catch(Exception e){e.printStackTrace ();} pGw|T~e%
} /bA\O
Sd'Meebu
2,|*KN*e`W
private void processErrorCode(int nErrorCode) DJgk"'
{ Zrfp4SlZZ
System.err.println("Error Code : " + nErrorCode); 9/C0DDb
} Y{y #us1
bu"Jb4_a>
[o&Vr\.$
//停止文件下载 r$ue1bH}|
public void siteStop() }8WpX2U
{ j9C=m"O
bStop = true; K8*QS_*
for(int i=0;i<nStartPos.length;i++) J)(H-xvV
fileSplitterFetch.splitterStop(); EK.L>3
G[u_Uu=>
z.23i^Q
} EVmQ"PKL'
} (_]{[dFr%
//负责部分文件的抓取 BXueOvO8
**FileSplitterFetch.java Jl3l\I'
*/ KmV#% d
package NetFox; SqY;2:
k1>%wR
mm%w0dOb"
import java.io.*; qcke8Q
import java.net.*; `h5HA-ud
] d| -r:4
`(aU_r=
public class FileSplitterFetch extends Thread { Q"8)'dL'
Kbx(^f12
/6F 1=O(c>
String sURL; //File URL BieII$\P%P
long nStartPos; //File Snippet Start Position !_<.6ja
long nEndPos; //File Snippet End Position `ZN@L<I6
int nThreadID; //Thread's ID u]E%R&
boolean bDownOver = false; //Downing is over $Z10Zf=
boolean bStop = false; //Stop identical (o^V[zV
FileAccessI fileAccessI = null; //File Access interface _wM[U`H}s
H*|Bukgt/M
nL^6{I~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'DsfKR^s
{ V]H<:UE
this.sURL = sURL; M;zRf3S
this.nStartPos = nStart; R2Tvo?xI7
this.nEndPos = nEnd; O~d!*A
nThreadID = id; eJ{"\c(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SfJ/(q
} <!X'- >i%q
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hl}#bZ8]
public void run() ABhza|
{ f;u;hQxs
while(nStartPos < nEndPos && !bStop) PyYKeo=
{ ygpC1nN
mm#U a/~1u
R$,`}@VqZ3
try{ 1I3u~J3]/
URL url = new URL(sURL); yF0,}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JPQ02&e
httpConnection.setRequestProperty("User-Agent","NetFox"); +Q-~~v7,
String sProperty = "bytes="+nStartPos+"-"; @{I55EQ]
httpConnection.setRequestProperty("RANGE",sProperty); .U5+PQN
Utility.log(sProperty); f+xGf6V
@T/C<-/:
n^&QOII@>
InputStream input = httpConnection.getInputStream(); 8GlH)J+kq
//logResponseHead(httpConnection); I]SR.Yp%
fY%Sw7ql<
D4#,9?us
byte[] b = new byte[1024]; )CR8-z1`
int nRead; )STt3.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =j;o, J:(
{ '2[ _U&e
nStartPos += fileAccessI.write(b,0,nRead); njUM>E,'
//if(nThreadID == 1) w4L\@y3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D@ =.4z
} ?!~au0
{7/6~\'/@
fI$,?>
Utility.log("Thread " + nThreadID + " is over!"); `SW`d<+L
bDownOver = true; yAi4v[
//nPos = fileAccessI.write (b,0,nRead); 8#Z$}?W
} _4E+7+
catch(Exception e){e.printStackTrace ();} =Fj:#s
} 3"L$*toRA
} IL%&*B
\17)=W
Ue,"CQ6H
//打印回应的头信息 V;:A&
public void logResponseHead(HttpURLConnection con) $(CHwG-
{ T3?kabbF
for(int i=1;;i++) H`io|~Q
{ / TJTu_#
String header=con.getHeaderFieldKey(i); A1'IK.
if(header!=null) "t\9@nzdX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m",bfZ
Utility.log(header+" : "+con.getHeaderField(header)); ihYfWG|
else 0?`#ko7~d
break; 15s?QSKj
} 6)bfd^JYn
} 1^W Aps
Ys3C'Gc
~~fL`"
public void splitterStop() dF?pEet?2
{ X|q0m3jt
bStop = true; ftH 0aI
} B"B
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} ,`Mlo
#UI`G3w<
2'}2r ~6
/* x p$0J<2
**FileAccess.java 34l=U?
*//文件访问(定位，写) mcR!P~"i
package NetFox; kN) pi "
import java.io.*; V('b|gsEo
~G$OY9UC
zld>o3K}
public class FileAccessI implements Serializable{ Fca?'^X
nbRg<@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >L(F{c:
RandomAccessFile oSavedFile; z>&D~0
long nPos; tO0+~Wm
@kK=|(OB'
YS~x-5OE\
public FileAccessI() throws IOException *Xo f;)Z^
{ }B.C#Y$@
this("",0); eyG.XAP
} [/kO>
lt]U?VZ
. =5Jpo
public FileAccessI(String sName,long nPos) throws IOException d"cfSH;h
{ GhT7:_r~
oSavedFile = new RandomAccessFile(sName,"rw"); \X`P W
this.nPos = nPos; .`p_vS9
oSavedFile.seek(nPos); -I*A `M
} SM<kE<q#
lyPXlt
%qHT!aP
public synchronized int write(byte[] b,int nStart,int nLen) n" ~*9'
{ gdT_kb5HL8
int n = -1; ;0*^98K
try{ Rb0{t[IU
oSavedFile.write(b,nStart,nLen); 4s8E:I=K
n = nLen; `iI"rlc
} 4tU~ ^z
catch(IOException e) n\YxRs7 hF
{ Ss:,#|
e.printStackTrace (); K6U>Qums
} xRUYJ=|oh
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X3nhqQTZ
return n; l_%~X9"
} ("6W.i>
YPc<
SDwSlwf
} (?!0__NN;
6~S0t1/t?
[ lW "M
/* -Tx tX8v
**SiteInfoBean.java o0L#39`'g
*/ D2p6&HNT
package NetFox; c5R{Sl
G= cxc_9
\sd"iMEi
public class SiteInfoBean { Y zS*p~|
mW-W7-JhO7
E2IVR]C2^
private String sSiteURL; //Site's URL M<unQ1+wh
private String sFilePath; //Saved File's Path ArYF\7P
private String sFileName; //Saved File's Name 5KR|pFq
private int nSplitter; //Count of Splited Downloading File O:)IRB3
g-FZel
^mpB\D)q
public SiteInfoBean() NO^t/(Z
{//nSplitter的缺省值为5 @U{M"1zZe
//default value of nSplitter is 5 GJs[m~`8#
this("","","",5); RHVv}N0
} S$52KOo
GuWBl$|+b
HW726K*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PEEY;x
{ 7V (7JV<>
sSiteURL= sURL; vs|6ww
sFilePath = sPath; #\BI-zt
sFileName = sName; k+$4?/A
this.nSplitter = nSpiltter; G3+a+=e
L0b]^_tI
03WRj+w
} 2TEeP7
~q(C j"7
~^~RltY
public String getSSiteURL() tcEf ~|3
{ 7 afA'.=
return sSiteURL; YO$b#
} -_DiD^UcXn
jA4v?(AO}#
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public void setSSiteURL(String value) h<ctW>6v
{ n "KJB
sSiteURL = value; OW}j4-~wL
} H)T# R?
BC{J3<0bf@
OCO,-(
public String getSFilePath() t0H=NUP8
{ L_ qv<iM$
return sFilePath; 5zw23!
} 8sF0]J[g{
p]|ME
G!LNP&~
public void setSFilePath(String value) vKf;&`^qE
{ ^%$W S,
sFilePath = value; u$,Wyi )L
} MQH8Q$5D
|ezO@
Ox*T:5
public String getSFileName() [-Tt11
{ :G=1$gb
return sFileName; _&Uo|T
} Y1_6\zpA
+6)kX4
nBIv{
public void setSFileName(String value) YSz$` 7i
{ xKLcd+hCZ
sFileName = value; .'{6u;8
} dms:i)L2
y#Za|nt
aco}pXz
public int getNSplitter() (9 z.IH7}k
{ Ta\8>\6
return nSplitter; 3g#=sd!0O@
} '"fU2M<.
?]:EmP
2:HP5
public void setNSplitter(int nCount) A"<)(M+kG
{ Hs`#{W{.
nSplitter = nCount; ))69a
} (VXx G/E3
} K-Dk2(x
':2*+
pT;-1c%:
/* k1Mxsd
**Utility.java ~iR!3+yg4
*/ Up/u|A$0V
package NetFox; cM<hG:4%wX
MHr0CYyb.
k E#_Pc
public class Utility { ;'Vipj
A]O5+"mc
#9hXZr/8
public Utility() ~SR(K{nf#.
{ vLK\X$4
>]XaUQ-
>upXt?
} : `6$/DK
Eagmafu
//线程睡眠 Z>w^j.(
public static void sleep(int nSecond) D_19sN@0m
{ q{De&Bu
try{ Rqb{)L X*
Thread.sleep(nSecond); hA1gkEM2o
} ({H+ y 9n
catch(Exception e) &DbGyV8d"|
{ gcW{]0%L^
e.printStackTrace (); C>`.J_N
} WP%{{zR$
} ),y!<\oQ
bUAR<R'E
//日志 z5yb$-j
public static void log(String sMsg) +%le/Pg@
{ nzE,F\k
System.err.println(sMsg); {7Gx9(
} (9YYv+GGd*
'[=yfh
gM;)
public static void log(int sMsg) EDgob^>
{ [nN\{"~O
System.err.println(sMsg); LE0J ;|1
} Fyh?4!/.
} mOz&6T<|
V$Xl^#tN
&8X .!r`f
/* ENYF0wW
**TestMethod.java m_E[bDON
*/ M]4=(Vv+5
package NetFox; )ZgER[
C$'D]fX
68J 9T^84
public class TestMethod { ,>QMyI hv
L)R[)$2(g
_@BRpLs:4
public TestMethod() Hlt8al3
{ ///xx/weblogic60b2_win.exe !0!U01SWa
try{ ,{uW8L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~_l6dDJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'd2qa`H'}B
SiteFileFetch fileFetch = new SiteFileFetch(bean); D8@nkSP
fileFetch.start(); 4[LLnF--
} 6=G~6Qu
catch(Exception e){e.printStackTrace ();} ==h|+NFa
)y%jLiQv
E VN-<=i^
} [w&#+h-q
cD'HQ3+
f.aB?\"f6
public static void main(String[] args) !^)wPmk
{ J0ZxhxX35
new TestMethod(); sFQ4O- SM
} !cEbzb
} G%P>Ag
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