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)); "I0F"nQ
} THY=8&x)
for(int i=0;i<nEndPos.length-1;i++) AYGe`{
{ U5yBU9\G
nEndPos = nStartPos[i+1]; T7?cnK"
} !![HR6"Q
nEndPos[nEndPos.length-1] = nFileLength; 'g:.&4x_w
} ):7mK03J
} 7& 'p"hF
qyL!>kZr@
i)= \-C
//启动子线程 I6Ga'5bV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y&6 pc
for(int i=0;i<nStartPos.length;i++) G_S2Q @|Q
{ 1.I58(0~+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~_a$5Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S#*aB2ZS
nStartPos,nEndPos,i); <lTLz$QE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2:G/Oj h&]
fileSplitterFetch.start(); S`pBEM
} R?HuDxHk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L\xR<m<,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ffR<G&"n~b
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A,4Z{f83
nEndPos = " + nFileLength); Xx1eSX
// fileSplitterFetch[nPos.length-1].start(); Ud)2Mq1#M
Wo{4*~f
''H;/&nDX
//等待子线程结束 wL[{6wL
//int count = 0; =@!s[
//是否结束while循环 jIck!
boolean breakWhile = false; v(;n|=O
oAgU rl;R
1!;4I@W(I)
while(!bStop) M\9+?
{ xwojjiV
write_nPos(); ny1Dg$ui2
Utility.sleep(500); _ ($U\FW
breakWhile = true; TGGbO:s3
^00C"58A
t'[`"pp=
for(int i=0;i<nStartPos.length;i++) :{%~L4$HI
{ !M}ZK(
if(!fileSplitterFetch.bDownOver) IHv>V9yiG
{ >[S\NAE>
breakWhile = false; j%i6H1#.Z
break; UZ!It>
} _8e0vi!~2
} T@d4NF#
if(breakWhile) %*OQH?pyx}
break; {J-Ojw|Y b
4A)_D{(SH
_Uhl4Mh
//count++; kV4,45r
//if(count>4) @4Lol2
// siteStop(); dst!VO: M
} *fI\|%K
B?9"Ztb
M=4`^.Ocm
System.err.println("文件下载结束！"); @zT2!C?^L
} !:a^f2^=
catch(Exception e){e.printStackTrace ();} %v[KLMo'(
} @_ Tq>tOr&
T3PwM2em_`
's$/-AV
//获得文件长度 "Iacs s0;
public long getFileSize() 8Yf=)
{ =d/$B!t{
int nFileLength = -1; LeYI<a@n@$
try{ Wm/0Pi
URL url = new URL(siteInfoBean.getSSiteURL()); 4ULdf|oP"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,3Nna:~f
httpConnection.setRequestProperty("User-Agent","NetFox"); " :V@AT
. dJBv
1V-sibE
int responseCode=httpConnection.getResponseCode(); );{76
if(responseCode>=400) "p[3^<~uQ
{ ^(KDtc
processErrorCode(responseCode); 7h`t-6<!q
return -2; //-2 represent access is error fvj
} dg&GMo
izR#XeBm
[Xww`OUsh
String sHeader; rq:sy=;
6uxF<
M|7][!<G!
for(int i=1;;i++) (#+81 Dr
{ ysFp$!9Ux
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .x1.`Y
//Utility.log(in.readLine()); 0@&/W-VXg
sHeader=httpConnection.getHeaderFieldKey(i); 3*-!0
if(sHeader!=null) #JR$RH
{ zKThM#.Wa
if(sHeader.equals("Content-Length")) MHS|gR.c
{ g\H~Y@'{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v!AfIcEV
break; ?(M]'ia{
} d}wE4(]b
} |(uo@-U
else ? 3oUkGfn
break; B/B`=%~5_^
} fONycXM]
} }S{VR(i`J
catch(IOException e){e.printStackTrace ();} df/7u}>9
catch(Exception e){e.printStackTrace ();} h~q5GhY!9
"ZuA._
10_>EY`
Utility.log(nFileLength); oo1h"[
]+>Kl>@
|#Q0UM|'Q
return nFileLength; QiaBZAol
} l0E]#ra"
tO3#kV\,
TXqtE("BDl
//保存下载信息（文件指针位置） /1eeNbd
private void write_nPos() r+tHVh
{ oVd7ucnK
try{ _jaB[Q=By
output = new DataOutputStream(new FileOutputStream(tmpFile)); J^zB5W,)
output.writeInt(nStartPos.length); +y\o^w4sT
for(int i=0;i<nStartPos.length;i++) Dy{lgT0k
{ 8&CQx*
// output.writeLong(nPos); ~DS.b-E
output.writeLong(fileSplitterFetch.nStartPos); QE721y
output.writeLong(fileSplitterFetch.nEndPos); ]$U A5/a
} M3eFG@,
output.close(); 9{Igw"9ck
} Dn`
catch(IOException e){e.printStackTrace ();} |{MXDx
catch(Exception e){e.printStackTrace ();} 1JV-X G6
} 4ZkaH(a1
DH)E9HL
77'@U(
//读取保存的下载信息（文件指针位置） QkYKm<b
private void read_nPos() &g]s@S|%
{ 24\^{3nOK
try{ :es=T`("A8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nuw7pEW@?
int nCount = input.readInt(); H;#C NB<e
nStartPos = new long[nCount]; H%0WD_
nEndPos = new long[nCount]; T=CJUla
for(int i=0;i<nStartPos.length;i++) 0qW"b`9R
{ }|wC7*^)
nStartPos = input.readLong(); .UvDew/Y
nEndPos = input.readLong(); y[GqV_~?Y
} lUw=YM
input.close(); 55=YM'5]
} bk]g}s
catch(IOException e){e.printStackTrace ();} V7B%o:FZo
catch(Exception e){e.printStackTrace ();} |W}D_2
} :k2J &@8
5x!rT&!G
G/_xn5XDD
private void processErrorCode(int nErrorCode) B;nIKZ
{ !Z0S@]C
System.err.println("Error Code : " + nErrorCode); { T<[-"h
} 2nCHL'8N
.pH 4[~
gLlA'`!
//停止文件下载 [7 t
public void siteStop() ->Fsmb+R
{ <- R%
bStop = true; tg<bVA)E'J
for(int i=0;i<nStartPos.length;i++) V0n8fez b
fileSplitterFetch.splitterStop(); yZb})4.
IR32O,)
rS+ >oP}
} uWi pjxS
} #c9MVQ_
//负责部分文件的抓取 Q8_5g$X\
**FileSplitterFetch.java {mLv?"M]
*/ O%<+&Q7
package NetFox; iz+,,UH
\"$q=%vD
Jg$ NYs.xZ
import java.io.*; s !II}'Je
import java.net.*; X?]Mzcu
<~e*YrJ?-
JB!*{{
public class FileSplitterFetch extends Thread { I*pFX0+
?.ofs}
~/Y8wxg
String sURL; //File URL ^c"\%!w"O
long nStartPos; //File Snippet Start Position |BO5<`&I
long nEndPos; //File Snippet End Position W k"_lJ
int nThreadID; //Thread's ID ]SN5&S
boolean bDownOver = false; //Downing is over 7w\!3pv
boolean bStop = false; //Stop identical Djf~8q V!
FileAccessI fileAccessI = null; //File Access interface )-1$y+s>
ANR611-a
3Qp6$m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException J+`gr_&
{ m-qOyt
this.sURL = sURL; % QaWg2Y=
this.nStartPos = nStart; RG/P]
this.nEndPos = nEnd; {@Z*.G^
nThreadID = id; <4^y7]]F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -CPLgT
} 5!6}g<z&L
- @KT#
SQk5SP
public void run() }~#qDrK
{ t2qWB[r
while(nStartPos < nEndPos && !bStop) (e3?--~b6
{ l%`~aVGJ
5jTA6s9zA
Kn\$\?u
try{ H$&P=\8n
URL url = new URL(sURL); k7z{q/]M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "azrcC
httpConnection.setRequestProperty("User-Agent","NetFox"); =I+5sCF{g
String sProperty = "bytes="+nStartPos+"-"; &<C&(g{Z
httpConnection.setRequestProperty("RANGE",sProperty); u#Uc6? E
Utility.log(sProperty); dW#l3_'3T
`$[`C/h
MO79FNH2\
InputStream input = httpConnection.getInputStream(); .r@'9W^8
//logResponseHead(httpConnection); ^X<ytOd5
);^{;fLy%
'RCX6TKBnR
byte[] b = new byte[1024]; bvo }b-]E
int nRead; l`{JxVg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m RtE~~p
{ y;HJ"5.Mw
nStartPos += fileAccessI.write(b,0,nRead); f=40_5a6
//if(nThreadID == 1) u8[jD^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iS28p
} jyjK~!0
7me1:}4
65pC#$F<x
Utility.log("Thread " + nThreadID + " is over!"); C6,W7M[c
bDownOver = true; H3o Um1
//nPos = fileAccessI.write (b,0,nRead); :*lB86Ly
} LD}ZuCp!
catch(Exception e){e.printStackTrace ();} %5?0+~
} <' b%
} C8 2lT_7"
m2Q#ATLW
L+"5g@
//打印回应的头信息 Yy8%vDdJO
public void logResponseHead(HttpURLConnection con) zDofe*
{ G(y@Tor+
for(int i=1;;i++) YPsuG -is
{ q P>Gre
String header=con.getHeaderFieldKey(i); zLLe3?8:
if(header!=null) ]#x?[F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LP:C9Ol\
Utility.log(header+" : "+con.getHeaderField(header)); %y;Cgo[
else |(a<b
break; N{6Lvq[8
} l]o&D))R
} 'y.'Xj:l
#x|h@(y|
bI~(<-S~K
public void splitterStop() N!F ;!
{ -kd_gbnr3
bStop = true; (""1[XURQK
} YkLEK|d
`P<m`*
'\X<+Sm'
} 9L'R;H?L
3M{/9rR[
sX,oJIt
/* ye)CfP=ID\
**FileAccess.java D=nuK25
*//文件访问(定位，写) 1[vmK,N=E
package NetFox; 9RoN,e8!
import java.io.*; ApYri|^r
jnuovM!x~
:8bz+3p
public class FileAccessI implements Serializable{ 4=>4fia&D
^ cn)eA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }pa@qZXh
RandomAccessFile oSavedFile; |8b*BnS
long nPos; %K_[Bx{B
F$FCfP7
gekW&tRie
public FileAccessI() throws IOException .h2K$(/
{ joh=0nk;D
this("",0); sSC yjS'T
} X'Dg= |
j|&?BBa9
V Z[[zYe
public FileAccessI(String sName,long nPos) throws IOException 99}n%(V
{ N6Fj}m&E
oSavedFile = new RandomAccessFile(sName,"rw"); 9i8D_[
this.nPos = nPos; O>zM(I+p
oSavedFile.seek(nPos); 9Kw4K#IqQ
} '~3a(1@8
/YWoDHL
-<jb>8
public synchronized int write(byte[] b,int nStart,int nLen) iO;q]
{ k, )7v
int n = -1; 1q*85[Y
try{ g_}r)CgG|
oSavedFile.write(b,nStart,nLen); /H=fK
n = nLen; %Ysu613mz
} b<qv /t)$
catch(IOException e) ur-&- G^
{ nn"!x|c
e.printStackTrace (); :<w3.(Z
} 6>)]7(B<d
DNdwMSwp
qx<`Kc4
return n; KL!k'4JNY
} 6I(y`pJ
KP7bU9odJ
gEtDqq~y@
} BclZsU=xn
Y'-BKZv!
3=1aMQ
/* ?'p`Qv
**SiteInfoBean.java B3u5EgZr
*/ u4NMJnX
package NetFox; b5 YE4h8%
;Br8\2=$
g.X?wyg5
public class SiteInfoBean { B5u06O
Ob?>zsx
I@a7AuOw
private String sSiteURL; //Site's URL EkM?Rs
private String sFilePath; //Saved File's Path f.rz2)o
private String sFileName; //Saved File's Name &}VGC=F;d
private int nSplitter; //Count of Splited Downloading File *@lNL=%R
Ck2O?Ne
',`iQt!Lx
public SiteInfoBean() 3'O+
{//nSplitter的缺省值为5 KP[ax2!x
//default value of nSplitter is 5 _(3VzI'G
this("","","",5); 'O8"M
} T.GY
*f$mSI=
0tm%Kd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^6mlE+WY
{ 2BBGJE
sSiteURL= sURL; (ta!4h,
sFilePath = sPath; xIf,1g@Cq9
sFileName = sName; Z_D8}$!
this.nSplitter = nSpiltter; li8l+5d q
#QQ\xj
'N)&;ADx-G
} kYl$V=
NQ !t`
/_l%Dm?
public String getSSiteURL() rJ]iJ0[I
{ vUR{!`14
return sSiteURL; s\1h=V)!H
} WmP"u7I4
a9mLPP
v$s3f|Y
public void setSSiteURL(String value) `QXO+'j4
{ +'2Mj|d@p
sSiteURL = value; YwQxN"
} 9xyj,;P>
$GNN*WmHw
J"yO\Y
public String getSFilePath() j1*'yvGM
{ {'E%SIRZ)
return sFilePath; "n,">
} %N7b XKDP
3haYb`
z4b2t}
public void setSFilePath(String value) <w` R;
{ 21bvSK
sFilePath = value; f)l:^/WP+
} msM
S3EY9:^C
6x)7=_:0
public String getSFileName() ynvU$}w ~'
{ Xt^ldW
return sFileName; UBzX%:A
} I'HPy.PV
So{/V%
juG?kL.
public void setSFileName(String value) U<gMgA
{ F&%@p&
sFileName = value; _VGAh:v
} 3p6QJuSB
<k!M+}a 9V
3_|<CE6
public int getNSplitter() Xyy;BO:
{ 3}(6z"r
return nSplitter; ;>np2K<`
} !TvNT}4Z
g5M=$y/H
45. -P
public void setNSplitter(int nCount) `-fWNHs
{ [~*5uSG
nSplitter = nCount; ?!^ow5"8
} s!,m,l[P
} /4/'&tY
3}dTbr4y
V[ju7\>$Z
/* dp#JvZb
**Utility.java F]e`-;
*/ 2 j.6
package NetFox; DmU,}]#:
/By:S/[1pL
;\j7jz^uC
public class Utility { xfoQx_]$Im
Em)U`"j/9
pHQrjEF*
public Utility() "Vh3hnS~
{ GsIVx!
R !g'zS'
yq.<,b=87
} ebno:)
;)~}/nR<a
//线程睡眠 Vu.VH([b]Q
public static void sleep(int nSecond) /tm2b<G
{ $7h]A$$Fv
try{ Q^\m@7O :
Thread.sleep(nSecond); riR(CJ}Ff
} 5aj%<r
catch(Exception e) [|".j#ZlK
{ }NjZfBQW`
e.printStackTrace (); EfX\"y
} :HW| mqKd
} 8Q%g<jX*
'oKen!?A
//日志 |I[/Fl:
public static void log(String sMsg) >``sM=Wat
{ RW{y.WhB
System.err.println(sMsg); JBhM*-t(M1
} vtq$@#?~ b
kEgpF{"%n
pfBe24q
public static void log(int sMsg) }y%c.
{ apOXcZ
System.err.println(sMsg); Y5CDdn
} l-Be5?|{_
} zmU@ k
r<$o [,W
qk~m\U8r
/* m"@o
**TestMethod.java @(bg#
*/ ZDG~tCh=@
package NetFox; O1D|T"@
cJMi`PQ;
h;@c%Vm
public class TestMethod { Fw\g\
4O{G^;
^@3,/dH1 t
public TestMethod() MyZVx|7E
{ ///xx/weblogic60b2_win.exe 2X<%BFsE
try{ HfZ^ED"}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xp] jF^5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &wAVO_s
SiteFileFetch fileFetch = new SiteFileFetch(bean); m/Erw"Z
fileFetch.start(); l\F71pwSI
} nK32or3
catch(Exception e){e.printStackTrace ();} $ay!'MK0d
s7afj t
{,i-V57-h
} *Y?oAVkz
r;xy/*%Mtj
?JG^GD7D
public static void main(String[] args) DF_wMv:>^
{ PtYG%/s
new TestMethod(); +%v1X&_\
} >+Ig<}p
} tAE(`ow/Ur
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