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)); WjA)0HL(
} b]J_R"}
for(int i=0;i<nEndPos.length-1;i++) (5atU |8r
{ LDbo
nEndPos = nStartPos[i+1]; ]ao]?=q C
} \ii^F?+b
nEndPos[nEndPos.length-1] = nFileLength; ((H}d?^AJ
} 5:YtBdP
} H >RGX#|
+pDuRr
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//启动子线程 {gJOc,U4b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ny#7iz/
for(int i=0;i<nStartPos.length;i++) %T88K}?=
{ C=.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bd%/dr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z/;NoQ-
nStartPos,nEndPos,i); Qx {/izc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ptUnV3h
fileSplitterFetch.start(); W/+|dN{O+g
} ql],Wplg
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !QYqRH~5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fIFB"toiPE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q~`]0R159e
nEndPos = " + nFileLength); (}}BZS&.
// fileSplitterFetch[nPos.length-1].start(); Fn6>n04v
4$.4,4+
6W~F nJI
//等待子线程结束 9=hA#t.#
//int count = 0; /*st,P$"
//是否结束while循环 }bHdU]$}
boolean breakWhile = false; ==c\* o
l'$AmuGj
Bm^vKzp
while(!bStop) {y :/9
{ lPx4I
write_nPos(); 2&P'rmFm
Utility.sleep(500); )82x)c<e
breakWhile = true; n|{x\@VeF
|3vQmd !2}
>\MV/!W
for(int i=0;i<nStartPos.length;i++) ;o#dmG
{ .O~)zMx
if(!fileSplitterFetch.bDownOver) vk{dL'
{ $S6AqUk$
breakWhile = false; ?-*_v//g
break; {L3lQ8Z
} <Y9ps`{}:
} wxF9lZz
if(breakWhile) x"*u98&3
break; c6Wy1d^
N=-hXgX^
UiW(/L
//count++; )(y&U
//if(count>4) bp;)*
// siteStop(); E5.)ro=$
} /J1O{L
C <]rY
;Q-(tGd
System.err.println("文件下载结束！"); (%\N-[yZ
} eBG7]u,Q
catch(Exception e){e.printStackTrace ();} 2v yB[(
} iv\?TAZC
*h$Dh5%P
.~C*7_
//获得文件长度 |VTm5.23
public long getFileSize() f |aO9w
{ / [:@j+n\
int nFileLength = -1; 7@MVInV9
try{ T|r@:t[
URL url = new URL(siteInfoBean.getSSiteURL()); S+_}=25
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tOS%.0W5J
httpConnection.setRequestProperty("User-Agent","NetFox"); X,^J3Ek>O
i3N _wv{
rAk*~OK
int responseCode=httpConnection.getResponseCode(); fq_6xs
if(responseCode>=400) EcFYP"{U
{ )k=8.j4
processErrorCode(responseCode); [\eUCt F
return -2; //-2 represent access is error }kGJ)zh
} ,Rz,[KI|
zN*/G6>A
(lT H EiX
String sHeader; ME{i-E4
bvs0y7M='
,??xW{*|
for(int i=1;;i++) ~cQP4 kBD]
{ i$$\}2m{L
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >\[sNCkf
//Utility.log(in.readLine()); ^o65sM
sHeader=httpConnection.getHeaderFieldKey(i); }yC ve
if(sHeader!=null) ^pAqe8u_
{ tk2B\}6
if(sHeader.equals("Content-Length")) H+\rCefba
{ d8/lEmv[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SO3WOR`3
break; hPP+lqY[
} *ofK|r
} K-(,,wS
else "pQM$3n(
break; 9^)ochY3
} (Sv7^}j
} |l`X]dsfQ
catch(IOException e){e.printStackTrace ();} R84g<
catch(Exception e){e.printStackTrace ();} 2-. g>'W
}mk9-7
,m9Nd "6\
Utility.log(nFileLength); A:0
+|r) ;>b
n!A')]y"
return nFileLength; ycIT=AFYqd
} @| qnD
Y)?4OB=n
0q>f x
//保存下载信息（文件指针位置） ;Hv#SRSz
private void write_nPos() >pT92VN
{ ` L6H2:pf
try{ ^7vhize
output = new DataOutputStream(new FileOutputStream(tmpFile)); n +`(R]Q
output.writeInt(nStartPos.length); J9mLW}I?NW
for(int i=0;i<nStartPos.length;i++) r"zW=9 O=
{ >dn[oS,
// output.writeLong(nPos); w'#VN|;;!
output.writeLong(fileSplitterFetch.nStartPos); I^ppEgYSY
output.writeLong(fileSplitterFetch.nEndPos); 3JWHyo
} 3q{H=6
output.close(); Gq$9he<
} 84cmPnaT
catch(IOException e){e.printStackTrace ();} KSc&6UVz^
catch(Exception e){e.printStackTrace ();} QaUh+k<6
} &B/cy<;y,
*<OWd'LI
w[n|Sauy,
//读取保存的下载信息（文件指针位置） p$0;~1vH
private void read_nPos() 6WzE'0Nyr
{ qL,QsRwN
try{ #}^ZxEU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T<mk98CdE
int nCount = input.readInt(); RT F9;]Ti
nStartPos = new long[nCount]; vWXj6}
nEndPos = new long[nCount]; sO~N2
for(int i=0;i<nStartPos.length;i++) 1W"9u
{ Cx} Yp-
nStartPos = input.readLong(); oy;N3
nEndPos = input.readLong(); WIQt5=-
} kZWc(LwA
input.close(); l)Q,*i
} bv)E>%Yy
catch(IOException e){e.printStackTrace ();} Z:&"Ax
catch(Exception e){e.printStackTrace ();} b^;19]/RW
} t9zPJQlT}
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axxdW)+K
private void processErrorCode(int nErrorCode) <YUc?NF
{ =5+M]y E<
System.err.println("Error Code : " + nErrorCode); _C)u#]t
} &YmOXKf7
\@:pWe
Q{Jz;6"
//停止文件下载 v'TkKwl
public void siteStop() Z>Rd6o'
{ Mw\/gm_3
bStop = true; nv2Y6e}dG
for(int i=0;i<nStartPos.length;i++) mO?G[?*\
fileSplitterFetch.splitterStop(); wGBQ.Ve[
GQ$0`?lp
aGr(djD
} (t&P.N/
} T=ox;r
//负责部分文件的抓取 +7|Oy3s
**FileSplitterFetch.java BO#fzq%
*/ CDO_A\
package NetFox; MVe5j+8
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C' o4Su#
import java.io.*; 3Nsb@0
import java.net.*; Ni(D[?mZ
@j9yc
Z@RAdwjR`p
public class FileSplitterFetch extends Thread { 'lHtz~[
:{E3H3
Fu^^Jex
String sURL; //File URL aEy_H-6f
long nStartPos; //File Snippet Start Position ]zhFFq`
long nEndPos; //File Snippet End Position ^pKC0E[%
int nThreadID; //Thread's ID o{f n}
boolean bDownOver = false; //Downing is over X:j&+d2g0/
boolean bStop = false; //Stop identical #ie{!Mh
FileAccessI fileAccessI = null; //File Access interface Y\%R6/Gj|u
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u8~.6]Ae
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z }R-J/xr2
{ q^n6"&;*
this.sURL = sURL; {>5z~OV
this.nStartPos = nStart; V.1sb pI
this.nEndPos = nEnd; ~*LH[l>K
nThreadID = id; H-1@z$p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ts}5Nk8%
} 1&i!92:E
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public void run() x1|5q/I
{ oQjh?vm
while(nStartPos < nEndPos && !bStop) pn{.oXomf
{ $qP9EZ]JC
s,]6Lri`\
6$%]p1"!K
try{ jQ%}e"
URL url = new URL(sURL); !r.X.C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .: 87B=
httpConnection.setRequestProperty("User-Agent","NetFox"); K%2,z3ps
String sProperty = "bytes="+nStartPos+"-"; FOquQr1cF
httpConnection.setRequestProperty("RANGE",sProperty); n`vqCO7@'
Utility.log(sProperty); e&<#8;2X
IW$&V``v
oT\B-lx
InputStream input = httpConnection.getInputStream(); G\*`EM4
//logResponseHead(httpConnection); IN ,@
%vxd($Ti"
1Q#hanh_`
byte[] b = new byte[1024]; _&19OD%
int nRead; l1gAm#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FT[wa-b
{ sOzjViv
nStartPos += fileAccessI.write(b,0,nRead); )n5]+VTZ5
//if(nThreadID == 1) N95"dNZE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U87VaUr
} [0m'a\YE9
o:f=dBmoX
7M3q|7?
Utility.log("Thread " + nThreadID + " is over!"); ^}U{O A
bDownOver = true; : b $ M
//nPos = fileAccessI.write (b,0,nRead); <!5N=-
} !+U#^2Gz
catch(Exception e){e.printStackTrace ();} ENA8o}n
} 9} eIidwK
} TcauCL
UF D_
;=_<\2
//打印回应的头信息 C]A*B
public void logResponseHead(HttpURLConnection con) N]KqSpPh
{ l"CHI*
for(int i=1;;i++) h&h]z[r R
{ }\JoE4
String header=con.getHeaderFieldKey(i); k8Qv>z
if(header!=null) va~:oA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _~HGMC)
Utility.log(header+" : "+con.getHeaderField(header)); `zZ=#p/
else e%wbUr]c2
break; [EB2o.EsO
} B?#@<2*=L
} v@Otp
)K8JDP
ir \d8.
public void splitterStop() djZOx;/
{ I".d>]16|
bStop = true; D;BFl(l
} kki]6_/n
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T/-PSfbkj
} o"7,CQye
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{D1=TTr^
/* B 8C3LP}?
**FileAccess.java {7Dc(gNS
*//文件访问(定位，写) + #S]uC
package NetFox; Kqhj=B
import java.io.*; gAv?\9=a)W
fCx~K'UWn
/3FC@?l w4
public class FileAccessI implements Serializable{ 5IVASqYp
^R>&^"oI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,i>5\Yl%
RandomAccessFile oSavedFile; U~Uxs\0:
long nPos; luat1#~J
BIw9@.99B-
3zs~Y3M?i
public FileAccessI() throws IOException 0ZkA.p
{ N<$uAns
this("",0); KXicy_@DC`
} B<8Z?:3YS
[#lPT'l
DFE?H
public FileAccessI(String sName,long nPos) throws IOException @@SG0YxZ
{ A' dt WD
oSavedFile = new RandomAccessFile(sName,"rw"); WdunI~&.
this.nPos = nPos; _wZ(%(^I
oSavedFile.seek(nPos); /x0zZ+}V
} M~ynJ@q
z4UeUVfZ}
Pg*ZQE[ME8
public synchronized int write(byte[] b,int nStart,int nLen) AD*+?%hj
{ ~|l>bf
int n = -1; lYQcQ*-
try{ > {fX;l
oSavedFile.write(b,nStart,nLen); mR8&9]g&
n = nLen; # ?}WQP!
} 3o"~_l$z
catch(IOException e) R%7k<1d'`
{ -qid.
e.printStackTrace (); &S''fxGL
} Nm#KHA='Z
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,((5|MbM/
return n; xV<NeU
} oVc_(NH-
L.+5`&
K V 4>(
} I#uJdV|x
QVzLf+R~
7Py8!
/* )ae/+Q8
**SiteInfoBean.java crZ\:LeJ
*/ _W]3_1Lu
package NetFox; mgH4)!Z*56
Tvf]OJ9N
6`X#<#_&
public class SiteInfoBean { OEq8gpqY
}v=q6C#Q>
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private String sSiteURL; //Site's URL hj0uv6t.c
private String sFilePath; //Saved File's Path a/>={mbKi
private String sFileName; //Saved File's Name lFI"U^xC
private int nSplitter; //Count of Splited Downloading File .i[Tp6'%,
o6B!ikz 8
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public SiteInfoBean() +de.!oY
{//nSplitter的缺省值为5 LLaoND6
//default value of nSplitter is 5 o*5|W9
this("","","",5); 0r:8ni%cL
} ]<++w;#+x
ph^qQDA
B-r9\fi,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) r95$B6
{ -I\_v*nA
sSiteURL= sURL; mIl^
sFilePath = sPath; bLaD1rnGi
sFileName = sName; l3l[jDa,2
this.nSplitter = nSpiltter; [dOPOA/d
F4">go
Z1^S;#v
} ?A,gDk/#
8.]dThaq
vP88%I;
public String getSSiteURL() 2 B5kpmH:
{ @f{)]I +f
return sSiteURL; [x-Z)Q.5
} ke)3*.Y%C
"o=h /q5&
%"+FN2nbm
public void setSSiteURL(String value) }JrM!'
{ BD,~M*%z
sSiteURL = value; {7B$%G'
} OO53U=NU
gt{ei)2b
TZ-n)rC)v
public String getSFilePath() B\Rq0N]' M
{ ]'2p"A0U
return sFilePath; .+{nfmc,c
} !Bu<6
|wVoJO!O}
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public void setSFilePath(String value) %oC]Rpdu
{ \=,+weGw@
sFilePath = value; B^{bXhDp
} v|QFUa`
Tje =vI
VY~WkSi[<
public String getSFileName() 1sn!!
{ v_)cp9d]
return sFileName; 6mMJ$FY+
} &e3z)h
oaRPYgh4
KJcdX9x
public void setSFileName(String value) B'atwgI0
{ 9r\8 !R
sFileName = value; ^ /:]HG
} 8>Ervi`
=NyzX&H6
P%B1dRa
public int getNSplitter() r`wL_>"{n
{ 5\EHu8
return nSplitter; 'HW(RC0dR
} J>XaQfzwU
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*~2jP;$
public void setNSplitter(int nCount) iT9cw`A^%
{ bLSI\
nSplitter = nCount; ?aO%\<b
} -aKL 78
} {TE0
Ldt7?Y(V(
J6NQ5S\
/* >i@gR
**Utility.java k 2;m"F
*/ Fk=_Q LI
package NetFox; e0>@Yp[Kd
Me5umA
Pgye{{
public class Utility { ;@v7AF6Hq
8q_3*++D
owYfrf3ZLX
public Utility() >Z<ym|(T*
{ |mY<TWoX
Nk}Hvg*(
;$[o7Qm5r
} VJHHC.Kz
7b@EvW6X}
//线程睡眠 3S'V>:
public static void sleep(int nSecond) R%3H"FU9w
{ |W*f6F3
try{ !!Mp;h'}-
Thread.sleep(nSecond); #8nF8J<4
} 9OT2yCT
catch(Exception e) &\Cvrxa
{ EB@!?=0x
e.printStackTrace (); a-i#?hld
} Z4hP
} HzH_5kVW
W,AIE6F
//日志 &sx/qS#,VL
public static void log(String sMsg) { H9pF2C
{ CAcnH
System.err.println(sMsg); n (cSfT
} \2eYw.I=
}})4S;j
8 _`Lx_R
public static void log(int sMsg) ?:n{GK
{ tGM)"u-
System.err.println(sMsg); Of([z!'Gc
} Ie4*#N_
} uz'beE
|W:kzTT-T
ua7I K~8l
/* ~}4H=[Zu
**TestMethod.java nwcT8b87J
*/ 8Bhot,u'T
package NetFox; s8eiq`6\H}
r<C^hs&]
o~es>;
public class TestMethod { z{!wQ~ j
&\!-d%||)
B*DH^";t
public TestMethod() nV']^3b
{ ///xx/weblogic60b2_win.exe a[9;Okm#
try{ Wuc,Cjm9(!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1Rp|*>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |U7{!yy%MF
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ej.D!@
fileFetch.start(); %$sWNn
} wJ IJPYTK
catch(Exception e){e.printStackTrace ();} #+ n &
r% mN]?u
G ROl9xp2
} m^]/ /j
HJg)c;u/2;
=797;|B H
public static void main(String[] args) YT&_{nL#\
{ #o yvsS8
new TestMethod(); rt~X(S
} 3_Oq4/
} B8a!"AQ~5
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