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)); _1Rw~}O
} '_7rooU9
for(int i=0;i<nEndPos.length-1;i++) 'Q=)-
{ {HM[ )t0
nEndPos = nStartPos[i+1]; Jlb{1B$7
} EKcPJ\7
nEndPos[nEndPos.length-1] = nFileLength; &-o5lrq
} lb9?Uc@
} N LQ".mM+
f U=P$s
:zo5`[P
//启动子线程 1yz%ud-l
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9[X'9*,
for(int i=0;i<nStartPos.length;i++) .czUJyFms}
{ Fhllqh)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y@$E5sz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]=ApYg7!
nStartPos,nEndPos,i); P5B,= K>r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YCStX)r
fileSplitterFetch.start(); At<MY`ka
} 'OTZ&;7{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^Os }sJ*5S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V,VL?J\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?(R#
nEndPos = " + nFileLength); &qPezyt
// fileSplitterFetch[nPos.length-1].start(); -0q|AB<
N2 3:+u<)E
A{-S )Z3}
//等待子线程结束 fnr8{sr.2Z
//int count = 0; Q[#8ErUY
//是否结束while循环 3f^jy(
boolean breakWhile = false; *^g]QQ
Z2g<"M
{Mb<onW
while(!bStop) ng|^Zm%
{ @8`I!fZ
write_nPos(); 3B%7SX
Utility.sleep(500); G na%|tUz|
breakWhile = true; W;R6+@I[
'{~[e**
WvF{`N
for(int i=0;i<nStartPos.length;i++) Q\IViM
{ "1a!]45+
if(!fileSplitterFetch.bDownOver) Hc<@T_h+2
{ Q3=5q w^
breakWhile = false; y2?9pVLa\y
break; PHT<]:"`<
} E=,b;S-
} 5Hj/7~ =
if(breakWhile) W{q P/R
break; R#ZJLT
Sn'!Nq>
6y Muj<L
//count++; '3^qW
//if(count>4) CDtL.a\
// siteStop(); V D7^wd9
} 4?@#w>(
|[5;dt_U/
A9SL|9Q
System.err.println("文件下载结束！"); n2-+.9cY
} ami>Pp
catch(Exception e){e.printStackTrace ();} 3SbZD
} 2+)h!y]
mh[,E8'd
kR^">s/H#
//获得文件长度 MIkp4A
public long getFileSize() z]%@r 7
{ d)biMI}<5
int nFileLength = -1; rq7yNt
try{ 3k>#z%//
URL url = new URL(siteInfoBean.getSSiteURL()); GwDOxH'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NWiDNK[VE}
httpConnection.setRequestProperty("User-Agent","NetFox"); 5QXU"kWH
}oG6XI9
iNi1+sm
int responseCode=httpConnection.getResponseCode(); LzLJ6A>;R
if(responseCode>=400) Bx}"X?%S
{ _nzq(m1@
processErrorCode(responseCode); IMdp"
return -2; //-2 represent access is error _(gkYJ+MK
} # SCLU9-
,Js_d
.WN&]yr,
String sHeader; |zfFB7}v
y_W?7S
@VOegf+N
for(int i=1;;i++) NRG~ya >
{ ?xMTO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !.V_?aYi8
//Utility.log(in.readLine()); O"TVxP:
sHeader=httpConnection.getHeaderFieldKey(i); 2<n18-|OQ
if(sHeader!=null) OPq|4xu
{ ,-EN{ed
if(sHeader.equals("Content-Length")) Brs}
{ >m%TUQ#%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 't8!.k
break; RaTNA W)v>
} NW0se DL
} yVn%Bz' [
else =z9,=rR4
break; 7|dm"%@
} j?$B@Zk
} DH_~,tK9
catch(IOException e){e.printStackTrace ();} mM/#(Ghl
catch(Exception e){e.printStackTrace ();} 6.45^'t]
<=%[.. (S
uw8g%
Utility.log(nFileLength); qR2cRepV
(dNF)(wn
,mCf{V]#
return nFileLength; _O87[F1
} `hG`}G|^
N`N=}&v ]
T$r/XAs
//保存下载信息（文件指针位置） 7g{JE^u
private void write_nPos() o8E<_rei
{ hB\BFVUSn/
try{ j+AZ!$E
output = new DataOutputStream(new FileOutputStream(tmpFile)); W6EEC<$JL
output.writeInt(nStartPos.length); twldwuN
for(int i=0;i<nStartPos.length;i++) " @""
{ ^qC.bv]&
// output.writeLong(nPos); 75R4[C6T
output.writeLong(fileSplitterFetch.nStartPos); #LR6wEk
output.writeLong(fileSplitterFetch.nEndPos); .*YOyK3H
} h \`(
output.close(); oui0:Vy<
} UBQtD|m\
catch(IOException e){e.printStackTrace ();} suhnA(T{
catch(Exception e){e.printStackTrace ();} .':17 $c`H
} c"`HKfL
uW[AnQ1w
Z9% u,Cb
//读取保存的下载信息（文件指针位置） OH n~DL2
private void read_nPos() :Zq?V`+M
{ JDnWBEV
try{ L!/{Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); e>!]_B1ad
int nCount = input.readInt(); t*BCpC}
nStartPos = new long[nCount]; H)*%eG~
nEndPos = new long[nCount]; loq2+(
for(int i=0;i<nStartPos.length;i++) &2@Rc?!6_P
{ ;Cx`RF w
nStartPos = input.readLong(); ~^Ga?Q_
nEndPos = input.readLong(); >c:nr&yP
} HH(2
input.close(); &V&beq4)p
} 7{S;~VH3
catch(IOException e){e.printStackTrace ();} )Rk(gd
catch(Exception e){e.printStackTrace ();} ~k 6V?z}
} Ug gg!zA
/-@F|,O)$n
V~o'L#a
private void processErrorCode(int nErrorCode) #gf0*:p
{ :N<o<qn
System.err.println("Error Code : " + nErrorCode); =-P<v2|e
} ~$ ?85
<Z~Nz>'r
|z}VP-L
//停止文件下载 2Z^p)
public void siteStop() Gh{9nM_\"
{ ?5pZp~
bStop = true; \!>qtFT
for(int i=0;i<nStartPos.length;i++) ZL!5dT&@W
fileSplitterFetch.splitterStop(); ~^ '+.
!]7L9TGn
3dtL[aVwY
} ]wbV1Y"
} 3<a|_(K
//负责部分文件的抓取 fx^yC.$2
**FileSplitterFetch.java l0',B*og
*/ %3HF_DNOY=
package NetFox; $Zrc-tkV
pwVGe|h%,
J<cY'?D
import java.io.*; .k!2{A
import java.net.*; a*_" nI&lr
sC :.}6
Y{4nBu
public class FileSplitterFetch extends Thread { `v/p4/
7Z}T!HFMr
%|2x7@&s
String sURL; //File URL e<u~v0rDl
long nStartPos; //File Snippet Start Position Fb{HiU9<!
long nEndPos; //File Snippet End Position 1[RI 07g7*
int nThreadID; //Thread's ID vBY?3p,0p
boolean bDownOver = false; //Downing is over R\6dvd
boolean bStop = false; //Stop identical #N97
FileAccessI fileAccessI = null; //File Access interface _w5c-\-PUM
!.|A}8nK
te>Op 1R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x+Ly,9nc$
{ q?0&0
this.sURL = sURL; 1yc$b+TH
this.nStartPos = nStart; 8)f/H&)>8
this.nEndPos = nEnd; R&/"?&pfa
nThreadID = id; skt9mU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 e&<=+\ul
} v+d`J55
e:QH3|'y
j2hp*C'^
public void run() gb^'u
{ cS#| _
while(nStartPos < nEndPos && !bStop) >(Wt
{ [/J(E\9
&_]bzTok
8feLhWg'P
try{ /)Weg1b
URL url = new URL(sURL); 9J}^{AA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E,A9+OKxJ
httpConnection.setRequestProperty("User-Agent","NetFox"); immf\
String sProperty = "bytes="+nStartPos+"-"; 8tT/w5
httpConnection.setRequestProperty("RANGE",sProperty); _tnoq;X[
Utility.log(sProperty); /EVXkf0
]6WP;.[
|5BvVqn
InputStream input = httpConnection.getInputStream(); kL -f@CD
//logResponseHead(httpConnection); wFL7JwK:G
]#FQde4]5
kxY9[#:<fB
byte[] b = new byte[1024]; ;l@Ge`&u
int nRead; <+<,$jGC-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v +?'/Q%
{ SXV f&8
nStartPos += fileAccessI.write(b,0,nRead); =d JRBl
//if(nThreadID == 1) @`SlOKz!=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3`njQvI\
} [5P1 pkZ
&:=[\Ws R
~2XiKY;W?
Utility.log("Thread " + nThreadID + " is over!"); 9@ ^*\s
bDownOver = true; OL@' 1$/A
//nPos = fileAccessI.write (b,0,nRead); 2 3A)^j
} S<++eu
catch(Exception e){e.printStackTrace ();} !!v9\R4um
} Q3LScpp
} l]5!$N*
((fFe8Rn)q
C7MCMM|S
//打印回应的头信息 7}Jn`^!
public void logResponseHead(HttpURLConnection con) QLH6Nmk
{ MBFn s/
for(int i=1;;i++) }Szs9-Wns
{ tHH @[E+h
String header=con.getHeaderFieldKey(i); ]ex2c{ G
if(header!=null) tj" EUqKQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); arn7<w0
Utility.log(header+" : "+con.getHeaderField(header)); YD;"_yH
else v<]$,V]
break; 9E
} e[.JS6
} hJoh5DIE95
4~0@(3
]7%+SH,RdD
public void splitterStop() TmgSV#G
{ J/A UOInh
bStop = true; a+`;:tX,
} BbNl:`
1lHBg
t[bZg9;
} NKu*kL}W=
X}]g;|~SN
k{+Gv}Y
/* m^1'aO_;q
**FileAccess.java 9Qc=D"'
*//文件访问(定位，写) ~qb-uT\(99
package NetFox; 24d{ol)
import java.io.*; @Yzb6@g"
,mD{4 >7
(fC U+
public class FileAccessI implements Serializable{ h_xzqElZu
FmtV[C#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5[rA>g~
RandomAccessFile oSavedFile; qa/VSk!{
long nPos; *>7Zc
#}nDX4jI
8FT@TUFb
public FileAccessI() throws IOException Ug^vVc)
{ bqm%@*fZo
this("",0); J]$]zD
} C +S>;1
T|h'"3'
Ku]<$uo
public FileAccessI(String sName,long nPos) throws IOException 95BRZ!ts
{ xayd_RB9
oSavedFile = new RandomAccessFile(sName,"rw"); :@sjOY
this.nPos = nPos; TM`6:5ONv
oSavedFile.seek(nPos); w?A6S-z
} p!p:LSk"/b
tD3v`Ke
[O^mG 9
public synchronized int write(byte[] b,int nStart,int nLen) Q~$hx{foN
{ Gq;!g(
int n = -1; tp3 !6I6
try{ $or8z2d1
oSavedFile.write(b,nStart,nLen); 9{n?Jy
n = nLen; |Ht~o(]&&/
} fTV}IP
catch(IOException e) ?8@EBPpC
{ kk7M$)>d
e.printStackTrace (); E'F87P^>
} 4j-%I7
s7na!A[
oD7^9=#
return n; _[ufH*
} >$N ?\\#
sGFC?1r?\
OA8iTn
} aX(Y `g)|
OW1\@CC-69
OmC F8:\/
/* +p_>fO
**SiteInfoBean.java f-a+&DB9
*/ {t QZqqdn@
package NetFox; 5jK9cF$>
DeRC_ [
-!pg1w06
public class SiteInfoBean { _6{XqvWqb
*odwg$
kU[#. y=%p
private String sSiteURL; //Site's URL J={IGA
private String sFilePath; //Saved File's Path l*>,:y
private String sFileName; //Saved File's Name SOo}}a0
private int nSplitter; //Count of Splited Downloading File YV/JZc f
RI-)Qx&!f
2f7]=snCG
public SiteInfoBean() zUd{9B$
{//nSplitter的缺省值为5 zFeo8S
//default value of nSplitter is 5 /WJ+e
this("","","",5); 04QY x}a
} J+=+0{}
guWX$C-+1
_16IP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '"o&BmF
{ g0-J8&?X
sSiteURL= sURL; p;YS`*!s
sFilePath = sPath; s!F` 0=J^
sFileName = sName; 2]f?c%)I
this.nSplitter = nSpiltter; EiWsVic[
.]H1uoci|
2vx1M6a)L
} ! )PV-[2
n>:|K0u"
I\:(`)"r
public String getSSiteURL() +JRPd.B"@
{ -mAi7[omh
return sSiteURL; N2Q%/}+,
} |sklY0?l(
sj\kp ni
)-_To&S*
public void setSSiteURL(String value) $kCLS7 *
{ Iji9N!Yx
sSiteURL = value; %SlF7$
} B_#U|10et
c6f[^Q%#j
'r_NA!R
public String getSFilePath() ]9/{
{ }KCb5_MDF
return sFilePath; :~{x'`czJ
} fPu,@ L
8^|lsB}x?
UCF'%R
public void setSFilePath(String value) z]O,Vqpl?
{ QpC,komLJ
sFilePath = value; .cA'6J"Bm\
} :bV1M5
DQRr(r~2Kj
>xJh!w<pB
public String getSFileName() w,v~
{ 9$oU6#U,h
return sFileName; 1feS/l$
} I-?Dil3
Jt}0%C3d
&S|%>C{P.w
public void setSFileName(String value) hAv.rjhw_
{ _k2*2db
sFileName = value; nFY6K%[
} VQ((c:+!
oD>j26Q
:Mq-4U.e
public int getNSplitter() q=(.N>%
{ 5<?s86GHh'
return nSplitter; |'" 17c&
} ri?>@i-9=
p!]$!qHO(
u#uT|a.
public void setNSplitter(int nCount) c[QXc9
{ 8#&axg?a
nSplitter = nCount; #\X="'/
} Yl!~w:O!o
} +IpC
xesZ7{ o
\vQjTM-7
/* v;m}<3@'
**Utility.java pk,]yi,ZF
*/ ,]UCq?YW)T
package NetFox; GIGC,zP@k
JTn\NSa
x."/+/
public class Utility { bO2s'!x
ohPCYt
quEP"
public Utility() L 2k?Pl
{ 8Q2qroT
':jsCeSB
xOAA1#
} ~$\9T.tre2
Fw!TTH6l0
//线程睡眠 6*]g~)7`Q~
public static void sleep(int nSecond) q;<=MO/
{ m5/d=k0l
try{ B"rfR_B2M#
Thread.sleep(nSecond); f8c'`$O
} _R 6+bB$
catch(Exception e) 6bXR?0$*M.
{ ToVi;
e.printStackTrace (); ;&N=t64"
} vL,:Yn@b
} &+v!mw>
Xbp~cn
//日志 v3`k?jAaI
public static void log(String sMsg) 3r]:k)J
{ ~Os1ir.
System.err.println(sMsg); SL O~
} I}S~,4
9AgTrP
X>W2aDuEZ
public static void log(int sMsg) V{yP/X
{ /P>t3E2c
System.err.println(sMsg); ZgP~VB0)$
} 1'G&PX
} X?8EPCk
qij<XNZU"&
I\DH
/* XFiP8aX<
**TestMethod.java &=-ZNWNo
*/ qlJzXq{|`
package NetFox; &eqeQD6
*49lM;
[$<\*d/
public class TestMethod { ..5rW0lr
(&)PlIi7
8wXnc%
public TestMethod() CC8)yO
{ ///xx/weblogic60b2_win.exe g]V_)}
try{ m@Vz42g~+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @*VfG CQ(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v,VCbmc
SiteFileFetch fileFetch = new SiteFileFetch(bean); $xK2M
fileFetch.start(); 2`?58&
} ip`oL_c
catch(Exception e){e.printStackTrace ();} jrl'?`O
y|7sh
~.*G%TW &V
} .a0]1IkatV
$k,wA8OZ-
&P@dx=6d
public static void main(String[] args) Q,f~7IVX
{ b-+~D9U<
new TestMethod(); 0S%xm'|N
} l 7XeZ} S
} nN]GO}
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