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)); bHI<B)=`
} V,[d66H=N
for(int i=0;i<nEndPos.length-1;i++) wX*K]VMn
{ :,DM*zBVp
nEndPos = nStartPos[i+1]; 7H|$4;X^
} 5Fz.Y}
nEndPos[nEndPos.length-1] = nFileLength; Q"7Gy<
} "1-}A(X
} _IdRF5<4
HWVtop/
o#hjvg
//启动子线程 L*x[?x;)@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \2vg{
for(int i=0;i<nStartPos.length;i++) nO)X!dp}J
{ =k oSUVO0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 51QRM32Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7k(Kq5w.
nStartPos,nEndPos,i); t&(PN%icD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %DQhM,c@
fileSplitterFetch.start(); V3ndV-uQE
} RTFZPq84
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]7Z{ 8)T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); H`geS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >|Cw\^
nEndPos = " + nFileLength); R+7oRXsu
// fileSplitterFetch[nPos.length-1].start(); yZWoN&
1u|Rl:Q
ZZyDG9a>7
//等待子线程结束 j6g[N4xr
//int count = 0; A mwa)
//是否结束while循环 # (- Qx
boolean breakWhile = false; %~QO8q_7
LbII?N8`N
Tt>8?
while(!bStop) +z$pg
{ O%ug@& S{
write_nPos(); W\L`5CW
Utility.sleep(500); "ax..Mh\y
breakWhile = true; <u=4*:QE
|> _!eS\=<
>pr=|$zk=
for(int i=0;i<nStartPos.length;i++) 36n>jS&
{ e*.b3z
if(!fileSplitterFetch.bDownOver) VnT>K9&3
{ SnYLdwgl
breakWhile = false; H&yD*@
break; XB[<;*Iz
} 0j_bh,zG#
} 8O"U 0
if(breakWhile) .E@|D6$D
break; RO3oP1@B
-!8(bjlJ&
_A~4NW{U7
//count++; :#lIx%l
//if(count>4) ${8?N:>t
// siteStop(); 4Ua>Yw0
} 1lpwZ"
-&e92g&n
[JaS??ig
System.err.println("文件下载结束！"); wlPx,UqZ
} @p|$/Z%R,
catch(Exception e){e.printStackTrace ();} F]I=+T
} $.:mai
W k}AmC
X.TI>90{
//获得文件长度 nJbbzQ,e
public long getFileSize() (S^8UV
{ Ou>vX[{
int nFileLength = -1; )}L??|#
try{ YQ0)5}
URL url = new URL(siteInfoBean.getSSiteURL()); |~ _'V "
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^bLRVp1
httpConnection.setRequestProperty("User-Agent","NetFox"); 8_!.!Kde |
v{<[)cr
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int responseCode=httpConnection.getResponseCode(); [+Y{%U
if(responseCode>=400) DE IB!n
{ emW:C-/h/@
processErrorCode(responseCode); v~/~@jv
return -2; //-2 represent access is error d HJhFw
} 9*:gr#(5
wIf {6z{
,]5Ic.};p
String sHeader; _xLHrT!y
X1vNF|o~
HBB{m
for(int i=1;;i++) DSxUdEK6
{ .6~`Ubr}E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); **>/}.%?K
//Utility.log(in.readLine()); /xJqJ_70X
sHeader=httpConnection.getHeaderFieldKey(i); LZ~"VV^
if(sHeader!=null) $M:3XAN
{ Em7 WDu0
if(sHeader.equals("Content-Length")) J# kl 7
{ RL[E X5U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .O0O-VD+a
break; 9GdB#k6W`
} 3u33a"nL8
} 7}_!
else RB?V7uX
break; -xD*tf*
} ejXMKPE;
} Hk7K`9
catch(IOException e){e.printStackTrace ();} -]:GL>b
catch(Exception e){e.printStackTrace ();} 7'NS9|
[\Qr. 2
cubUq5
Utility.log(nFileLength); \x>65;
O3o: qly!
>ulY7~wUv
return nFileLength; \b*X:3g*
} ]8;n{ }X
#;#3%?
`8\Ja$ =
//保存下载信息（文件指针位置） /VHi>
private void write_nPos() H UWxPIu
{ .C]cK%OO N
try{ 3^=+gsc
output = new DataOutputStream(new FileOutputStream(tmpFile)); jKIc09H|
output.writeInt(nStartPos.length); 4Tct
for(int i=0;i<nStartPos.length;i++) V|MY!uV
{ ZlKw_Sq:
// output.writeLong(nPos); W9zE{)Sc~
output.writeLong(fileSplitterFetch.nStartPos); iK_c.b
output.writeLong(fileSplitterFetch.nEndPos); 5y4u5Tm-%
} y/c%+Ca/
output.close(); kWj \x|E
} ,572n[-q
catch(IOException e){e.printStackTrace ();} X%9*O[6{
catch(Exception e){e.printStackTrace ();} 4FMAz^
} Brd,Eg
Cz^Q5F`
StYzGJ
//读取保存的下载信息（文件指针位置） /Y^8SO4
private void read_nPos() nF)uTk
{ [XlB<P=|>
try{ "'Z- UV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [*m2
int nCount = input.readInt(); 4QJ8Z t
nStartPos = new long[nCount]; ] q~<=
nEndPos = new long[nCount]; GQ_Ia\
for(int i=0;i<nStartPos.length;i++) SJgY
{ o{-<L
nStartPos = input.readLong(); ;2giZ\
nEndPos = input.readLong(); f*xpE`&
} <JI& {1
input.close(); 1MA@JA:T
} G.U5)4_^
catch(IOException e){e.printStackTrace ();} 4-v6=gz.
catch(Exception e){e.printStackTrace ();} 5 ZfP
} Me:{{-V4
?PPZp6A3L=
v@EQ^C2.&
private void processErrorCode(int nErrorCode) yy(A(}
{ bb=uF1
System.err.println("Error Code : " + nErrorCode); F#+.>!
} Ey&aBYR
84&XW
~y0R'oi
//停止文件下载 uL?vG6% ^1
public void siteStop() 7]22"mc
{ d @rs3Q1z
bStop = true; t"s5\;IJ
for(int i=0;i<nStartPos.length;i++) UU@fkk
fileSplitterFetch.splitterStop(); 8}BBOD
PoD^`()FR{
'=cKU0 G#
} `EMi0hm&H
} msk/p>{O
//负责部分文件的抓取 $->d!
**FileSplitterFetch.java Q1tpCT
*/ 6/mF2&&g
package NetFox; rj H`
So4nJ><p
s'_,:R\VM>
import java.io.*; ms~8QL
import java.net.*; )fh0&Y; R
et$uP
.]76!(fWZ
public class FileSplitterFetch extends Thread { =ak7ldA=2
9XV^z*E(J
IjZ@U%g@;
String sURL; //File URL !Ua&0s%
long nStartPos; //File Snippet Start Position 0\a8}b||
long nEndPos; //File Snippet End Position [N|xzMe
int nThreadID; //Thread's ID {0's~U+@
boolean bDownOver = false; //Downing is over g*-2* \
boolean bStop = false; //Stop identical N\R=cwk
FileAccessI fileAccessI = null; //File Access interface Rrqg[F+
kR6A3?[
F!8=FTb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^@.G,u
{ Gq]d:-7l
this.sURL = sURL; ]h~o],:
this.nStartPos = nStart; D[>W{g $
this.nEndPos = nEnd; ^9ng)
nThreadID = id; M#0 @X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7U:=~7GH
} 6[==BbZ
,d 7Z
+8^_D?*\n
public void run() ^g!B.ll`
{ A4_>LO_qL
while(nStartPos < nEndPos && !bStop) :)P<jX-G
{ ,$Tk$
Vm!i
eoJ]4-WFq
try{ cgyo_ k
URL url = new URL(sURL); 4 iH&:Al
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v.`+I-\.z)
httpConnection.setRequestProperty("User-Agent","NetFox"); :t2B^})\
String sProperty = "bytes="+nStartPos+"-"; /PC`0/b
httpConnection.setRequestProperty("RANGE",sProperty); #%cR%Z
Utility.log(sProperty); jzrt7p*k}
6An{3"
`$-lL"
InputStream input = httpConnection.getInputStream(); dt~iw
//logResponseHead(httpConnection); ]P*!'iYN(
97x%w]kV
@}eNV~ROu
byte[] b = new byte[1024]; j-* TXog
int nRead; c$#GM57V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .3g&9WvN!Z
{ 2X_>vIlEm
nStartPos += fileAccessI.write(b,0,nRead); ;c)! @GoA
//if(nThreadID == 1) @+dHF0aXd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oEAfowXSqk
} ~V$ f#X
@"8~Y|L93
8_iHVc;<
Utility.log("Thread " + nThreadID + " is over!"); t F/nah
bDownOver = true; .&(8(C
//nPos = fileAccessI.write (b,0,nRead); 4e/cqN6
} sV'v* 1|
catch(Exception e){e.printStackTrace ();} |#cAsf_{
} 9cOx@c+/
} E$T(Qu<-
A\C'dZ <N
#HDesen
//打印回应的头信息 !Mil?^
public void logResponseHead(HttpURLConnection con) _m7co :
{ {]M>Y%j48
for(int i=1;;i++) .93S>U<_
{ )l{A{f6O
String header=con.getHeaderFieldKey(i); YOKR//|3
if(header!=null) N ^f}ui i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); > Z++^YVE
Utility.log(header+" : "+con.getHeaderField(header)); .Qk{5=l6P
else `]hCUaV
break; ZvyjMLf
} ;o%:7&
} IQoH@l&Xk
sU*3\
UKYupLu5
public void splitterStop() p5`ZyD]+
{ +3HPA#A
bStop = true; iUCwKpb9
} U IQ 6SvM
K#;txzi
)"-fHW+fy
} 7*g(@d
?.j,Bq5At
2MT_#r_
/* ?w8pLE~E
**FileAccess.java um}N%5GAa
*//文件访问(定位，写) 44<v9uSK
package NetFox; r?afv.@L2
import java.io.*; ^#7viZ*
fOJj(0=y
c&A]pLn+x
public class FileAccessI implements Serializable{ 7BK46x
776 nWw)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !*8#jy
RandomAccessFile oSavedFile; H-m`Dh5{
long nPos; &]*|6cR$E
aa!a&L|!
}JH`'&3
public FileAccessI() throws IOException *XOS.$zGz
{ B%y! aQep
this("",0); >eu `!8
} 8k%H[Smn:
gTuX *7w
XX:q|?6_ 4
public FileAccessI(String sName,long nPos) throws IOException V-:`+&S{^
{ 9kUV1?
oSavedFile = new RandomAccessFile(sName,"rw"); R;.d/U|av
this.nPos = nPos; 9g4QVo|
oSavedFile.seek(nPos); jvWI_Fto
} 7Qt2gf
/Q]:Uf.J
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public synchronized int write(byte[] b,int nStart,int nLen) BQuRHi IV
{ 7_1W:-A7W
int n = -1; B'!PJj
try{ G+fd.~aGE
oSavedFile.write(b,nStart,nLen); (}6wAfGo
n = nLen; #,)PN @P
} 3^'#ny?l
catch(IOException e) GU5W|bS
{ *|sxa#
e.printStackTrace (); Io09W^
} 98jD"*W5
.r(^h/IF
h1E PaL
return n; FBcm;cjH
} M,ppCHy/$
?C FS}v
[Yn;G7cK
} N*HH,m&
u1wg C#
kz$(V(k<
/* >QA/Mi~R
**SiteInfoBean.java 'G52<sF
*/ .Dc28F~t
package NetFox; +tPx0>p;
ofVEao
P4i3y{$V
public class SiteInfoBean { KU*`f{|
@pTD{OW?
SHytyd
private String sSiteURL; //Site's URL Q +R3H,
private String sFilePath; //Saved File's Path U2VV[e)Z!
private String sFileName; //Saved File's Name B<(Pd
private int nSplitter; //Count of Splited Downloading File omNpE_
`:V}1ioX5
uAc@ Z-
public SiteInfoBean() IPwj_jvw
{//nSplitter的缺省值为5 ZK%Kgk[\:~
//default value of nSplitter is 5 sbs[=LW4
this("","","",5); o?;F.W_
} `8mD7xsg$
RfD{g"]y
fFjLpl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U.HoFf+HN
{ .MzOLv
sSiteURL= sURL; mu 2 A%"7
sFilePath = sPath; @Q/x&BV
sFileName = sName; hEVjeC
this.nSplitter = nSpiltter; +SAk:3.#CV
~*jsB=XM/
@gH(/pFX
} @X3 gBGY)
Y>xi|TWN
nXv 7OEpTx
public String getSSiteURL() "xL;(Fqu
{ lv=yz\
return sSiteURL; e 4 p*51ra
} q-A`/9
fEx+gQW_
<jpeu^7
public void setSSiteURL(String value) Rrh<mo(yj#
{ x%_qJ]o
sSiteURL = value; oNiToFbQu
} := ]sq}IN
JmnBq<&,0
A4~D#V
public String getSFilePath() V"w`!
{ -iY9GN89c
return sFilePath; w> Tyk#7lw
} IXbdS9,>F
?BWHr(J
M(_^'3u
public void setSFilePath(String value) BM|-GErE
{ %'RI3gy
sFilePath = value; HiQoRk
} fBHkLRFH
= 4BLc
73&]En
public String getSFileName() $ /}:P
{ (eCF>Wh^m
return sFileName; 9 Q0#We*
} ,[Dh2fPM,
S4#A#a2J
N>uA|<b,
public void setSFileName(String value) S^3g]5YX
{ [$hptQv
sFileName = value; zAKq7'_=
} /Ki0+(4
p2pTs&}S
`E./p
public int getNSplitter() Rel(bA-[N
{ LFk5rv'sM0
return nSplitter; hEyX~f
} c%q}"Y0oh
J0IdFFZ|w
;FV~q{
public void setNSplitter(int nCount) !L&=?CX
{ Zp/qs z(]
nSplitter = nCount; ^2&O3s
} O!#L#u53
} \SYPu,ZT
&Iv\jhq
,Hik(22
/* IeRl6r%:
**Utility.java S(g<<Te
*/ sh',"S#=@
package NetFox; L#t-KLJ
o{ ,ba~$.w
*Gk<"pEeS
public class Utility { 3Ew"[FUs
a-z23$3
X";QA":
public Utility() ^yn[QWFO
{ '0'"k2"vC
hW0,5>[7%
Ff)~clIK '
} H3 A]m~=3
C$N4
//线程睡眠 [oQ`HX1g
public static void sleep(int nSecond) /7UovKKbz
{ 5~`|)~FA
try{ IQ(]66c,
Thread.sleep(nSecond); (5f5P84x
} t7U,AQ=;P5
catch(Exception e) 4=?Ok":8
{ 8>%jZ%`a
e.printStackTrace (); /{eih]`x(
} Z4wrXss~
} p%1xj2 ?nN
SXHru Z
//日志 F8|5_214'
public static void log(String sMsg) 1+16i=BF)
{ N=O+X~
System.err.println(sMsg); [[*0MA2Y
} bWX[<rh'
k$UzBxR
Mm>zpB`qP
public static void log(int sMsg) 3/A[LL|
{ 6k@%+<1
System.err.println(sMsg); C*W.9
} 9sfB+]}h
} \dp9@y[^
yZj}EBa
;qT!fuN;
/* (!XYH@Mz<w
**TestMethod.java JR? )SGB
*/ i(&6ys5
package NetFox; &9RW9u "
e-Ybac%
6g~o3
public class TestMethod { i-i}`oN
MrKU,-
|mQtjo
public TestMethod() )"pxry4v7J
{ ///xx/weblogic60b2_win.exe ery?G-
try{ \V"PmaP\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 07T;IV3#C5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j &0fC!k
SiteFileFetch fileFetch = new SiteFileFetch(bean); =E"kv!e
fileFetch.start(); |`q)/ 08b
} % L %1g
catch(Exception e){e.printStackTrace ();} iS:PRa1
rr07\;
FkJ>]k
} 2h|(8f:y
/C,>
|ZST Y}RXA
public static void main(String[] args) ?|Q5]rhs
{ VtzyB
new TestMethod(); .qqb>7|q
} \ ]kb&Qw
} bzj!d|T`
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