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)); F8q|$[nH
} BPW2WSm@<
for(int i=0;i<nEndPos.length-1;i++) HN\9d
{ 0y*8;7-|r)
nEndPos = nStartPos[i+1]; Uo# Pe@ieQ
} alyWp
nEndPos[nEndPos.length-1] = nFileLength; WOh?/F[@u
} i6aM}p<
} [&51m^
MGK%F#PM
qeypa!
//启动子线程 H+` Zp
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ta%yQd7
for(int i=0;i<nStartPos.length;i++) "d%o%
{ *y0TtEd;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6YNd;,it>p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^DD]jx
nStartPos,nEndPos,i); _->d41
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3v\}4)A[
fileSplitterFetch.start(); y2cYRHN[X}
} PY[nnoF"|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :>f}rq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JD9)Qelw^$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /V0[Urc@
nEndPos = " + nFileLength); HQX.oW
// fileSplitterFetch[nPos.length-1].start(); MR}=tO
,N93H3(
LtW}R4}3
//等待子线程结束 ~wvu7
//int count = 0; yw\Q>~$n[=
//是否结束while循环 QWcQtM
boolean breakWhile = false; f?W_/daP
Ir#]p9:x
Lcb5^e?'Q
while(!bStop) Q`kV| pjg
{ a`I \19p]
write_nPos(); wDR/Vr"f
Utility.sleep(500); i]9C"Kw$L
breakWhile = true; \(_(pcl
MQ#k`b#()
Np7+g`nG
for(int i=0;i<nStartPos.length;i++) 7vTzY%v
{ FRa>cf4
if(!fileSplitterFetch.bDownOver) galzk$D
{ Uo?4o*}
breakWhile = false; (@m/j2z
break; Fs"i fn0
} Qp7h|<
} `J]e.K
if(breakWhile) Qo32oT[DM
break; .do8\
(@->AJF1\
bgLa`8
//count++; JR8|!Of@B
//if(count>4) S/"G=^~
// siteStop(); ^hXm=r4ozR
} eR%\_;}7;
=p^$>o
&(oA/jFQ
System.err.println("文件下载结束！"); )(0if0D4
} )r^vrCNy>
catch(Exception e){e.printStackTrace ();} tn#cVB3
} w?>f:2(=[
l`.z^+!8@
!( >U3N
//获得文件长度 ;plBo%EBV
public long getFileSize() qg{gCG
{ "\i H/
int nFileLength = -1; K[kK8i+(
try{ E*O($tS
URL url = new URL(siteInfoBean.getSSiteURL()); NB1KsvD{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]!ox2m_U
httpConnection.setRequestProperty("User-Agent","NetFox"); WG A1XQ{
D'<L6w`
D6Au)1y=&
int responseCode=httpConnection.getResponseCode(); ;89kL]
if(responseCode>=400) iLch3[p%
{ vn+XY=Qnr
processErrorCode(responseCode); o2X95NiH
return -2; //-2 represent access is error eT+i&
} }/dk2!?ig
pJx7S sW
j*@@H6G
String sHeader; 9j|v D
;Ax-f04gG
VE-l6@`
for(int i=1;;i++) w%.hALN5-C
{ & ?xR
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }%p:Xv@X!
//Utility.log(in.readLine()); tBbOxMm0
sHeader=httpConnection.getHeaderFieldKey(i); 9Q=VRH:
if(sHeader!=null) ep=r7Mft
{ &nP0T-T5y
if(sHeader.equals("Content-Length")) ]R_R`X?
{ /1MmOB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RqgN<&g?
break; :a6LfPEAX
} TY)QE
} gYD1A\
else 4d`YZNvZW/
break; c`soVqT$?
} j@>D]j
} H"FK(N\
catch(IOException e){e.printStackTrace ();} nd]SI;<
catch(Exception e){e.printStackTrace ();} X>8,C^~$1
g3z/yj
y6nP=g|')>
Utility.log(nFileLength); 8@;]@c)m
zMR)w77
q2*A'C
return nFileLength; -NXxxK
} !HvA5'|:}
pR$(V4>
|tGUx*NN
//保存下载信息（文件指针位置） 6N#hN)/
private void write_nPos() U?#wWbE1
{ P9/ (f$=
try{ ^+SE_-+]
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7q+D}+ Xf
output.writeInt(nStartPos.length); fZ$b8
for(int i=0;i<nStartPos.length;i++) T&lgWOls
{ TI'v /=;)
// output.writeLong(nPos); =vbG'_[7
output.writeLong(fileSplitterFetch.nStartPos); 053bM)qW
output.writeLong(fileSplitterFetch.nEndPos); QWk3y"5n<
} UDHWl_%L
output.close(); cD0rU8x
} {Sf[<I
catch(IOException e){e.printStackTrace ();} ,WRm{v0f^
catch(Exception e){e.printStackTrace ();} U05;qKgkDF
} vkIIuNdDlx
&"^F;z/
Ca|egQv
//读取保存的下载信息（文件指针位置） E+aePoU
private void read_nPos() ?H=q!i
{ L}`/v]E"eU
try{ Am<5J,<uy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xU.1GI%UPu
int nCount = input.readInt(); fzIs^(:fl
nStartPos = new long[nCount]; ; ~pgF_
nEndPos = new long[nCount]; r[S(VPo[()
for(int i=0;i<nStartPos.length;i++) J#I RbO)
{ +/ZIs|B4,z
nStartPos = input.readLong(); <E2 IU~e
nEndPos = input.readLong(); aUaeK(x:H
} #7]Jz.S
input.close(); ,U~A=bsa
} h3o'T=`Sm
catch(IOException e){e.printStackTrace ();} k,:W]KD
catch(Exception e){e.printStackTrace ();} >Uw:cq
} )0VL$A
jE*{^+n
7*l$i/!
private void processErrorCode(int nErrorCode) z`zz8hK.
{ geme_
System.err.println("Error Code : " + nErrorCode); eFG/!b<17
} 3`bQ0-D;
;P91'B~t
{7o3wxsS
//停止文件下载 /65YHXg,
public void siteStop() -G(me"Cu
{ .nPOjwEx&Y
bStop = true; JOJ.79CT
for(int i=0;i<nStartPos.length;i++) XQo\27Fo
fileSplitterFetch.splitterStop(); Lc{AB!Br
ANhqS
iXDG-_K
} 9{u=
} F7DA~G!
//负责部分文件的抓取 =I# pXL
**FileSplitterFetch.java YnEyL2SuU
*/ 'H530Y\
package NetFox; |0n )U(
6 9>@0P
?()*"+N(ck
import java.io.*; W'C>Fn}lO?
import java.net.*; 7hHID>,o9%
0V:H/qu8>
TxJk.c
public class FileSplitterFetch extends Thread { OG5{oH#K
t#^Cem<
1SExlU
String sURL; //File URL 7kLurv
long nStartPos; //File Snippet Start Position #_DpiiS,.Q
long nEndPos; //File Snippet End Position Nx 42k|8
int nThreadID; //Thread's ID g88k@<Y
boolean bDownOver = false; //Downing is over jZA1fV
boolean bStop = false; //Stop identical tm~9XFQ<
FileAccessI fileAccessI = null; //File Access interface 0>28o.
;/Hr ZhOE
&qx/ZT
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A(2 0+
{ V'kBF2}
this.sURL = sURL; dla_uXtM6
this.nStartPos = nStart; 1CC0]pyHX
this.nEndPos = nEnd; cfTT7O#Dc
nThreadID = id; y\??cjWb]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |/Vq{gxp+
} eKiDc=@
3~`P8 9
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public void run() 'gY?=,dF>
{ "Hw%@]#
while(nStartPos < nEndPos && !bStop) RdX+:!lD
{ tK3$,9+
> "hP
Ti? "Hr<W
try{ m6i ,xn
URL url = new URL(sURL); Qsbyy>o)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hkPMu@BI
httpConnection.setRequestProperty("User-Agent","NetFox"); hi(b\ABx
String sProperty = "bytes="+nStartPos+"-"; 5iw\F!op:
httpConnection.setRequestProperty("RANGE",sProperty); #(tdJ<HvC|
Utility.log(sProperty); z4YDngf=4
N3u06
/4;mjE
InputStream input = httpConnection.getInputStream(); y6$a:6
//logResponseHead(httpConnection); $n<1D -0!r
-b!?9T?}
RvR.t"8
byte[] b = new byte[1024]; #N][-i
int nRead; #6M |T+=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5Ew( 0K[
{ 6 wN*d 5
nStartPos += fileAccessI.write(b,0,nRead); ^]o H}lwO
//if(nThreadID == 1) n/v.U,f&l@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cxR.:LD}
} .rBU"Rbo
0Z2XVq~T$
;-3&yQ7N)
Utility.log("Thread " + nThreadID + " is over!"); X5o*8Bg4M
bDownOver = true; q7CLxv &QG
//nPos = fileAccessI.write (b,0,nRead); pLu5x<
} aVR!~hvFs
catch(Exception e){e.printStackTrace ();} ;MQl.?vj
} N:B<5l '
} k~)CJ6}
>~,~X9
"M:ui0YP
//打印回应的头信息 \`y:#N<c
public void logResponseHead(HttpURLConnection con) N8nt2r<h
{ UlWmf{1%]?
for(int i=1;;i++) >,,`7%Rv
{ Ar)EbGId
String header=con.getHeaderFieldKey(i); |Ua);B~F
if(header!=null) nReIi;pi
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ! VT$U6
Utility.log(header+" : "+con.getHeaderField(header)); E]Mx<7;\.
else "EpH02{i
break; q]1p Q)\'p
} O1\4WG%
} qb;b.P?~D$
3[Q7'\
E,d<F{=8,o
public void splitterStop() 29=ob("
{ s/ABT.ZO
bStop = true; 53hX%{3
} &B5&:ib1D
`a52{Wa
R?1Z[N
} o~'p&f
^Zvb3RJg
a=W%x{
/* '`;=d<'
**FileAccess.java Z'A 3\f
*//文件访问(定位，写) qMEd R;o
package NetFox; ;%0kzIvP
import java.io.*; bj`GGxzOb
iuj%.}
H*G(`Zl}
public class FileAccessI implements Serializable{ sf$hsPC^
Y;R,ph.a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g}R#0gkdk}
RandomAccessFile oSavedFile; E-^(VZ_Xj
long nPos; 9Tr ceL;
Ytc[ kp
48z%dBmTT*
public FileAccessI() throws IOException <b'*GBw$
{ ];CIo> b_(
this("",0); eV%{XR?y
} auGK2i
BEax[=&W
xyo~p,(~t
public FileAccessI(String sName,long nPos) throws IOException +@uA
{ j|8!gW
oSavedFile = new RandomAccessFile(sName,"rw"); y=sae
this.nPos = nPos; Lios1|5
oSavedFile.seek(nPos); ..Dm@m}
} /&\V6=jA1
Pm#/j;
)a0l:jEOc
public synchronized int write(byte[] b,int nStart,int nLen) ;HAvor=?
{ #yIHr&'oX
int n = -1; dLGHbeZ[(
try{ W\-`}{B_/
oSavedFile.write(b,nStart,nLen); 2ZV; GS#
n = nLen; 2!LDrvPP
} 3{.]!
catch(IOException e) f"gYXaVF+
{ #qk=R7"Q
e.printStackTrace (); /":/DwI'
} _'mC*7+
j=U"t\{
FO>!T@0G
return n; =}tomN(F~[
} (`slC~"
=RXeN+ &R
6|'7Mr~\
} ;o)'dK
s]e`q4ip
8pf]M&
/* T}z? i
**SiteInfoBean.java x]`F#5j
*/ >&fD:y'&
package NetFox; Kg~D~ +j
QuMv1)n
G>:v1lde
public class SiteInfoBean { ~$>JYJj
qi~-<qW
[(g2u@
private String sSiteURL; //Site's URL 2.</n}g
private String sFilePath; //Saved File's Path zOA~<fhT
private String sFileName; //Saved File's Name Uc_}="
private int nSplitter; //Count of Splited Downloading File g$2#TWW5
[;aM8N
/2d>nj
public SiteInfoBean() 1P"{TMd?
{//nSplitter的缺省值为5 QKEtV
//default value of nSplitter is 5 T^MY w
this("","","",5); wbOYtN Y@
} !wUznyYwt
'/XP4B\(E
W$wX[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0\"#Xa+}8
{ d 4tL
sSiteURL= sURL; !0? B=yA
sFilePath = sPath; byE0Z vDM
sFileName = sName; l'Za"TL:
this.nSplitter = nSpiltter; |15!D
ts(u7CJd
wT19m
} _1Rw~}O
4Dn&+=fq
t zd#9 #
public String getSSiteURL() Z5oDj|&l}
{ _#v"sGmN
return sSiteURL; l]D$QT3
} 'bLP#TAzf
j&/+/s9N
lijTL-3
public void setSSiteURL(String value) _:NQF7X#ug
{ r?Mf3U^G
sSiteURL = value; PfU\.[l$
} #>KiX84
NwOV2E6@OW
6q'Q?Uw^
public String getSFilePath() ,6MJW#~]
{ Hmm0H6&u
return sFilePath; 'MX|=K!C
} !%}n9vr!}\
)M"NMUuU"
e<{d{
public void setSFilePath(String value) Qp[ Jw?a
{ p),*4@2<
sFilePath = value; E0VAhN3G\
} u59l)8=
{R63n
ny+r>>3Td
public String getSFileName() mzM95yQ^Z
{ ZZ{c
return sFileName; T#!% Uzz
} U5-8It2OR
.]KC*2
f^hJAZ
public void setSFileName(String value) z]hRc8g}d
{ B_[I/ ?
sFileName = value; $ S3b<]B
} _3%:m||,XP
Y)lr+~84f
><IWF#kUA
public int getNSplitter() IEm~^D#<=
{ (||qFu9a
return nSplitter; 'ParMT
} 8Uh|V&
SD*q+Si,1U
1k:yU(
public void setNSplitter(int nCount) KI#v<4C$P
{ C4PT(cezR
nSplitter = nCount; #6#n4`%ER
} R!/JZ@au<
} 4P)#\$d:
? .SiT5
]D5Maid+
/* bWb/>hI8 Q
**Utility.java t {1 [Ip
*/ w+j\Py_G"
package NetFox; 2.Ww(`swL
Z@x&
GK,{$SC+=
public class Utility { PX^k;
uUHWTyoO
3SbZD
public Utility() 2+)h!y]
{ H!}L(gjEG
z}-R^"40
D}}?{pe
} >*O5Ry:4
?&,6Y'"
//线程睡眠 SfPQ;s'
public static void sleep(int nSecond) ,vvfk=-
{ 8Vn
try{ 1V[ZklS
Thread.sleep(nSecond); saZK+kD4I
} q[P>s{"
catch(Exception e) QaEiPn~
{ A0A|cJP
e.printStackTrace (); W[`ybGR<
} (>u1O V
} IMdp"
KLG.?`h:
//日志 c8
public static void log(String sMsg) .WN&]yr,
{ TBJ?8W(
System.err.println(sMsg); @VOegf+N
} ^J^~5q8
WwnBe"7M
*]<=04v]R
public static void log(int sMsg) YZOwr72VL
{ hTZ6@i/pS
System.err.println(sMsg); )$f?v22
} *UW 8|\;
} BH^*K/^
-*w2<DCn
{U3jJ#K
/* yVn%Bz' [
**TestMethod.java b0h\l#6
*/ [X@{xF^vBQ
package NetFox; af6<w.i
+RpCh!KP
zCA8}](C^
public class TestMethod { txnH~;(
t'W6Fmwkx
B[8RBTsA
public TestMethod() 7yg{0a
{ ///xx/weblogic60b2_win.exe &``nD
try{ ]P7gEBi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5lzbg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >#mKM%T2MJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); RYC%;h
fileFetch.start(); Ym]g0a
} hV`?, ~K
catch(Exception e){e.printStackTrace ();} hF^JSCDz l
>zJkG9a
RDQ]_wsyKG
} zn= pm#L
t W
s2N'Ip
public static void main(String[] args) q2*)e/}H
{ ]!P6Z?
new TestMethod(); tZ@&di:-F
} hTby:$aCg
} J'=s25OWU
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