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)); i?GfY C2q
} a^*cZ?Ta
for(int i=0;i<nEndPos.length-1;i++) <XQN;{xSa
{ AI1@-
nEndPos = nStartPos[i+1]; :DtZ8$I`]C
} UF&0&`@
nEndPos[nEndPos.length-1] = nFileLength; Vs_\ykO
} r6d0x
} k4qLB1&,
z5XYpi_;[
_M8G3QOx
//启动子线程 :3KO6/+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IajD;V
for(int i=0;i<nStartPos.length;i++) (KT38RhA
{ 1MbY7!?PG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R'Kt=.s<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &mN'Tk
nStartPos,nEndPos,i); pU?{0xZH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 81GQijq
fileSplitterFetch.start(); >_;kTy,
} 6gj]y^}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )KSisEL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :/o C:z\h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", { 1+Cw?1d
nEndPos = " + nFileLength); A",eS6
// fileSplitterFetch[nPos.length-1].start(); ]b4pI*:$I
Ik`O.Q.}
F(Lb8\to\M
//等待子线程结束 5;IT64&]
//int count = 0; _PK}rr?"7O
//是否结束while循环 $Y8>_6%+T
boolean breakWhile = false; 99<4t$KH
E%<w5d.lq
v<L=!-b^
while(!bStop) nd.57@*M
{ J.1O/Pw!.a
write_nPos(); P@qMJ}<j
Utility.sleep(500); 7~_{.f
breakWhile = true; Yo>`h2C4
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).pO2lLF4
for(int i=0;i<nStartPos.length;i++) /8f>':zUb
{ an3~'g?
if(!fileSplitterFetch.bDownOver) h/,R{A2mO
{ u@<Pu@?xm
breakWhile = false; :lUX5j3
break; K@B" ]6
} 8O,?|c=>
} P+[QI U
if(breakWhile) 30D:ZmlY
break; qs=Gj?GwGQ
lc]V\'e
?#d6i$
//count++; =v.{JV#
//if(count>4) kW#S]fsfU
// siteStop(); q[-|ZA bbr
} n'THe|:I
N? M
1o8wy_eSs
System.err.println("文件下载结束！"); 0s1'pA'
} G3G/xC"
catch(Exception e){e.printStackTrace ();} $30oc Tt{
} W7t >&3l
|~z3U>
Odm#wL~E
//获得文件长度 IE2CRBfs
public long getFileSize() YQ; cJ$
{ N1%p"(
int nFileLength = -1; f0vJm
try{ T'E] i!$
URL url = new URL(siteInfoBean.getSSiteURL()); u^Vh.g]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <0#^7Z
httpConnection.setRequestProperty("User-Agent","NetFox"); YydA6IK4
j.DHqHx
Bz?l{4".
int responseCode=httpConnection.getResponseCode(); xq2V0Jp1u
if(responseCode>=400) X/l;s
{ _3/ec]1
processErrorCode(responseCode); 5y]io Jc9-
return -2; //-2 represent access is error %Uy%kN_&
} 'TL2%T/)t
jo}1u_OJ
ygN>"eP
String sHeader; [& ^RP,N~
} ~| k
8'_ 0g[s
for(int i=1;;i++) @xS]!1-
{ i\)3l%AK]T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gw^'{b
//Utility.log(in.readLine()); fxd0e;NAAh
sHeader=httpConnection.getHeaderFieldKey(i); kx:jI^
if(sHeader!=null) f8=]oa]
{ 'f+NW&
if(sHeader.equals("Content-Length")) pLnB)z?
{ !;v.>.lw
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dQD$K|aUp
break; <*<U!J-i
} hd2'AlB
} aE)by-'
else :_xh(W+2<
break; y(5:}x&E
} /1d<P! H
} [}-3PpF
catch(IOException e){e.printStackTrace ();} CE ~@}`
catch(Exception e){e.printStackTrace ();} W\8Ln>
l+[czb~
~}'F887f
Utility.log(nFileLength); x GH1epf
Y/fJQ6DY
P|xG\3@Z
return nFileLength; gmP9j)V6
} dU_;2#3m
2'|8Q\,:4Z
0fArF*
//保存下载信息（文件指针位置） N|K4{Frm
private void write_nPos() y9L14
{ ^zr^ N?a
try{ jVWK0Zba
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^U@~+dw
output.writeInt(nStartPos.length); !yJICjXj
for(int i=0;i<nStartPos.length;i++) QJGKQ2^ n
{ ?X9UTOx
// output.writeLong(nPos); W0I4Vvh_"
output.writeLong(fileSplitterFetch.nStartPos); YcDe@Zuwn
output.writeLong(fileSplitterFetch.nEndPos); *[}^[J x
} =(o']ZaaA
output.close(); 5,)vJ,fs
} nZk+
catch(IOException e){e.printStackTrace ();} 4aUiXyr*2
catch(Exception e){e.printStackTrace ();} =QOg 6
} %*}Y6tl'|
"ju'UOcS/
iE].&>w
//读取保存的下载信息（文件指针位置） F@YKFk+a
private void read_nPos() 646JDX[o
{ g)"gw+ZFc
try{ sG7u}r
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eWs&J24
int nCount = input.readInt(); m Y,|J\w@
nStartPos = new long[nCount]; K.~q+IYP[
nEndPos = new long[nCount]; 3Q^fVn$tk
for(int i=0;i<nStartPos.length;i++) E_T2z4lw
{ L2UsqVU
nStartPos = input.readLong(); 1q7tiMvV-
nEndPos = input.readLong(); ino:N5&;;
} xc@Ss[
input.close(); j<<3Pr
} `G9 l
catch(IOException e){e.printStackTrace ();} 5GzFoy)j>
catch(Exception e){e.printStackTrace ();} 3FE(}G
} soRv1)el
zp}eLm:=d
}H> ^o9
private void processErrorCode(int nErrorCode) [iP#VM-N
{ IxZb$h[
System.err.println("Error Code : " + nErrorCode); (V:E2WR
} X{xBYZv4
)!:sFa 1
w>; L{
//停止文件下载 ]}|byo
public void siteStop() e'%v1-&sP
{ *cuuzi&
bStop = true; V~G`kkNy
for(int i=0;i<nStartPos.length;i++) k <iTjI*N
fileSplitterFetch.splitterStop(); ElhRF{R
@gC=$A#
Fb`a~c~s
} a' Ki;]q
} `{k"8#4:qA
//负责部分文件的抓取 %ts^Z*3u
**FileSplitterFetch.java \MC-4Yz
*/ JxE53ev
package NetFox; ~c^>54
e}/Lk5q!
V&8VwF^-
import java.io.*; klg25#t
import java.net.*; gxz-R?.
m7a#qs;,
hI%bjuq
public class FileSplitterFetch extends Thread { ryF7
f"7O "6
3~S'LxV
String sURL; //File URL IN8>ZV`j)
long nStartPos; //File Snippet Start Position 00v&lQBW
long nEndPos; //File Snippet End Position ]^':Bmq
int nThreadID; //Thread's ID F'jWV5"*
boolean bDownOver = false; //Downing is over ]H-S,lmV
boolean bStop = false; //Stop identical %~L>1ShtU
FileAccessI fileAccessI = null; //File Access interface $vC1 K5sLk
MFTkqbc
J;_}lF9d@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X[`bMa7IB(
{ k.("3R6v:
this.sURL = sURL; \$0F-=w`8
this.nStartPos = nStart; `>0MNmu
this.nEndPos = nEnd; B`*ZsS=R-
nThreadID = id; p&+;w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5^']+5_vb
} *.L81er5~
kt`nbm|aw
/|#&px)G
public void run() 7+X:LA~U
{ "k]CW\H6z
while(nStartPos < nEndPos && !bStop) d ;vT ~;
{ O"Ku1t!
il|1a8M2~
~P~
try{ | N0Z-|
URL url = new URL(sURL); q0f3="
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^O^l(e!3
httpConnection.setRequestProperty("User-Agent","NetFox"); lY|Jr{+Ln
String sProperty = "bytes="+nStartPos+"-"; U2uF&6v
httpConnection.setRequestProperty("RANGE",sProperty); }*.0N;;C
Utility.log(sProperty); *K> l*l(f]
=]:>"_jN
GKN%Tv:D_
InputStream input = httpConnection.getInputStream(); GpZc5c
//logResponseHead(httpConnection); I%- " |]$
t]7&\ihZi~
n6s}ww)
byte[] b = new byte[1024]; n1!?"m!
int nRead; *OuStr \o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Cmc3k,t
{ foJdu+^
nStartPos += fileAccessI.write(b,0,nRead); ,9WBTH8
//if(nThreadID == 1) sR/b$j>i3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O'Js}
} W6On93sa
9Xx's%U
Cvn#=6V3
Utility.log("Thread " + nThreadID + " is over!"); ()~pY!)1/
bDownOver = true; 7S?4XyU/o
//nPos = fileAccessI.write (b,0,nRead); LpR3BP@At
} `rf_7
catch(Exception e){e.printStackTrace ();} +$oF]OO
} ]\7]%(
} J_s>N
v|U(+O
ZDbc
//打印回应的头信息 rn<PR*
public void logResponseHead(HttpURLConnection con) #1>X58I^
{ @)Ofi j
for(int i=1;;i++) jBegh9KHq
{ fk_o@ G!0
String header=con.getHeaderFieldKey(i); sQMFpIrr
if(header!=null) DGzw8|/(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); In`mtn q
Utility.log(header+" : "+con.getHeaderField(header)); ]Kr `9r),
else 4~B> 9<$e>
break; 6R=W}q4
} Q+YRf3$
} OE}*2P/M>
N^3N[lD{
_q~=~nub
public void splitterStop() ;[fw]P n
{ s`0QA!G{-
bStop = true; ki85!k=Q2
} % LJs
J>/w5$h5
{GC?SaK
} x g0iN'e'K
?M[ A7?
;VWAf;U;B
/* $sEy%-
**FileAccess.java 'Fmvu
*//文件访问(定位，写) o<N nV
package NetFox; EVoEszR
import java.io.*; TYy.jFT-
V{JAB]?^
j$+nKc$
public class FileAccessI implements Serializable{ TA{\PKA)
g1jTy7g?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~Q\3pI. |
RandomAccessFile oSavedFile; 7D<#(CE{
long nPos; ]MxC_V+P`
{7)st W
ub|V\M{
public FileAccessI() throws IOException Y'ow
{ '#k0a,<N
this("",0); |`cKD >
} zzxGAVu
,lyb!k8
}`@728E
public FileAccessI(String sName,long nPos) throws IOException E2m8UBS
{ h=:Q-?n-
oSavedFile = new RandomAccessFile(sName,"rw"); VY3&
this.nPos = nPos; M8tRjNWS?
oSavedFile.seek(nPos); ;cQ6g` bM\
} 1R,:
l(02W
hRCed4qA
public synchronized int write(byte[] b,int nStart,int nLen) /Z$&pqs!
{ >/8yGBD
int n = -1; *NG+L)g
try{ <WcR,d
oSavedFile.write(b,nStart,nLen); U-|NY
n = nLen; uXKERzg
} Ry'= ke
catch(IOException e) _A=$oVe
{ ~m$Y$,uH
e.printStackTrace (); )gMG#>up@
} ~P@Q7T*
ypy68_xyW
-:na:Vsi
return n; PbmDNKEh{
} S;)w.
6Aku1h
tQjLOv+?=
} @~%r5pz6
kOed ]>H
"T|PS6R~
/* A -b [>}_
**SiteInfoBean.java *m#Za<_Gv
*/ yrlf+tl
package NetFox; Y 1t\iU
'hs2RSq
@w?P7P<O`
public class SiteInfoBean { #Jw1IcuH
*"{lMZ+
C<P%CG&;
private String sSiteURL; //Site's URL 2Tagr1L
private String sFilePath; //Saved File's Path }&[
private String sFileName; //Saved File's Name i(NdGL#P
private int nSplitter; //Count of Splited Downloading File fP. 6HF_p_
zR{W?_cV
xLC3>>P
public SiteInfoBean() 6E^.7%3
{//nSplitter的缺省值为5 |fHV2Y`:g
//default value of nSplitter is 5 v+X)Qmzf~
this("","","",5); RR]CW
} tfGHea)M
xjVS
<UQe.K"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !Y[lQXv
{ XR;eY:89
sSiteURL= sURL; eb=D/
sFilePath = sPath; #':fkIYe'
sFileName = sName; {62n7'U{
this.nSplitter = nSpiltter; QC9eUYe
fP(d8xTx2y
m+Rv+_R
} K[!&b0O
[_Qa9e
`a2n:F
public String getSSiteURL() RE/~#k@a
{ 1fZ(l"
return sSiteURL; u)~C;f)
} zc;|fHW~O
!K'}K>iT
o !vE~
public void setSSiteURL(String value) rv|)n>m
{ (w}H]LQ
sSiteURL = value; P7{gfiB
} Uk6HQQ
x;8A!8w
AD|2qM))
public String getSFilePath() ~x]jB
{ Yo|,]X>/
return sFilePath; <c2'0I >
} Z\k&gio5C^
\Hn>oonph
lx[oaCr
public void setSFilePath(String value) ,"HL~2:~
{ ;N0~;I
sFilePath = value; _Nqt21sL
} /K.!sQ$
"-+\R}q$
4#:W.]U8
public String getSFileName() ;{U@qQD7
{ ]3X@_NYj
return sFileName; y9>ZwYN
} ~2gG(1%At9
%3ICI
1f":HnLRM
public void setSFileName(String value) 3ZXQoC '
{ hMykf4
sFileName = value; TztAZ2C
} /(.mp<s0
sXD1C2o
E.Jkf\
public int getNSplitter() QmCe>+
{ Yq%9M=#k
return nSplitter; <gQIq{B?
} .MP !`
O vk_\On
GJoS#s
public void setNSplitter(int nCount) x7eQ2h6O
{ c'S,hCe*
nSplitter = nCount; M!REygyx
} F!]lU`z)=
} 7~5ym15*
?B}{GL2)
$h*L=t(
/* 8n*.).33
**Utility.java <w)r`D6
*/ U'<KC"f:'!
package NetFox; /Sc l#4bW
'lEA)&d
fvdU`*|n)
public class Utility { B(n{e53 9f
hHT_V2*
.ZJRO>S
public Utility() k[:bQ)H
{ <U!`J[n%
4Za7^c.
8&)DE@W
} w-t8C=Z
xT+zU}z
//线程睡眠 B#.L
public static void sleep(int nSecond) 6y9t(m
{ !g(KK|`,m
try{ QT>`^/]d
Thread.sleep(nSecond); U8LtG/
} G"Sd@%W(
catch(Exception e) er!DYv
{ :[hgxJu+
e.printStackTrace (); |~X ;1j!
} L;'"A#Pa
} ]y1OFKYv
Vp3ZwS
//日志 h3z{(-~y
public static void log(String sMsg) ?6fnpGX@a
{ @AIaC-,~]
System.err.println(sMsg); M>i9i-dU
} >76\nGO
VBcy9|lD
OeS\7
public static void log(int sMsg) ng_^
{ y*tZ !m2Gg
System.err.println(sMsg); C ihAU"
} /p+>NZ"b
} 'Pn3%&O$
Pyb Z)5u
Od5JG .]
/* /M3Y~l$
**TestMethod.java (tZrw5@
*/ JSTuXW
package NetFox; .MJofE;Jn
"F.;Dv9V[0
/q5v"iX]T
public class TestMethod { 37|&?||
3P^sM1
R)RG[F#
public TestMethod() }5}.lJ:
{ ///xx/weblogic60b2_win.exe =W BTm
try{ 6u7?dG'4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pm_u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fi$-;Gz
SiteFileFetch fileFetch = new SiteFileFetch(bean); sU@nc!&Y@
fileFetch.start(); Ux}(?Z
} Bhp-jq'!B
catch(Exception e){e.printStackTrace ();} _PlKhv}
)Ccq4i
Z3&_
} w &(|e <
f=mZu1(FZ
2|}+T6_q
public static void main(String[] args) Q^e}?v%=%3
{ Y<Fz)dQo
new TestMethod(); {O`w,dMOI
} '4|-9M3f
} }9W4"e2)
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