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)); U<0Wa>3zj
} ;&=CZ6vH
for(int i=0;i<nEndPos.length-1;i++) }.)R#hG?
{ S8dfe~|7:
nEndPos = nStartPos[i+1]; /B?wn=][
} aC2Vz9e
nEndPos[nEndPos.length-1] = nFileLength; 8QJr!#u
} jFdgFKc)
} 36(qe"s
en'[_43
&?bsBqpN
//启动子线程 ~/K&=xE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #rX^)2
for(int i=0;i<nStartPos.length;i++) WUie`p
{ qfl!>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zqm%qm:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X5/j8=G H`
nStartPos,nEndPos,i); =t-Ud^3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !9 kNL
fileSplitterFetch.start(); ;%2+Tc-7I
} gPB=Z!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lhYJectJa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Al*=%nY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j1g$LAe
nEndPos = " + nFileLength); '+/mt_re=
// fileSplitterFetch[nPos.length-1].start(); 9ns( F:
wsB-( 0-
4N$Wpx
//等待子线程结束 Ur< (TM
//int count = 0; J[6/dM
//是否结束while循环 elGBX h
boolean breakWhile = false; `PtB2,?
rhPv{6Z|7
& n@hD7=(
while(!bStop) .jqil0#)Y"
{ jc_k\
write_nPos(); /r'Fq =z
Utility.sleep(500); Z72%Bv
breakWhile = true; c!6v-2ykv
bS8$[7OhX
7=fNvES2
for(int i=0;i<nStartPos.length;i++) y|O3*`&m
{ TDR|*Cs
if(!fileSplitterFetch.bDownOver) L@[}sMdq(
{ V)~b+D
breakWhile = false; 3l~7
break; 1YMi4.
} n]#YL4j
} !O!:=wq
if(breakWhile) kYkA^Aq
break; +1cr6a
N<<wg{QO
#@BhGB`9Qt
//count++; yxu7YGp%
//if(count>4) ]SA/KV
// siteStop(); v2]N5
} ?SYmsaSr5
;U?=YSHk7
0AWxU?$A4
System.err.println("文件下载结束！"); X1B)(|7$
} H?r~% bh
catch(Exception e){e.printStackTrace ();} :^?-bppYW
} ,/p+#|>C=
Ou4hAm91s
$> QJ%v9+
//获得文件长度 Hfj.8$
public long getFileSize() nX7F<k4G2
{ -2}ons(
int nFileLength = -1; WNjG/U
try{ bvB7d`wx
URL url = new URL(siteInfoBean.getSSiteURL()); #B?lU"f8q^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k8n9zJ8
httpConnection.setRequestProperty("User-Agent","NetFox"); ECL{`m(#n
)UU`uzU;u
ehr\lcS<
int responseCode=httpConnection.getResponseCode(); 8hww({S2
if(responseCode>=400) X=?9-z] QO
{ ~P}ng{x4z
processErrorCode(responseCode); cy6YajOk7
return -2; //-2 represent access is error TW1`{SM
} 4s|qxCks
\anOOn@
{Q$8p2W
String sHeader; #lMIs4i.
8v/,<eARJ
.u&X:jOE
for(int i=1;;i++) H'$H@Kn]-
{ E]vox~xK>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S3HyB b
//Utility.log(in.readLine()); )Dhx6xM[a
sHeader=httpConnection.getHeaderFieldKey(i); :_HdOm
if(sHeader!=null) /z!y[ri+J
{ W^HE1Dt]
if(sHeader.equals("Content-Length")) 6X'0 T}
{ 7fWZ/;p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Xajt][
break; wU'+4N".
} J=kf KQV
} +pK35u
else mBye)q$
break; XkUwO ]
} @||nd,i`n~
} &QQ6F>'T
catch(IOException e){e.printStackTrace ();} D5Rp<PBq,
catch(Exception e){e.printStackTrace ();} } @3q;u)
\goiW;b
t&JOASYC
Utility.log(nFileLength); d7X7_
mg._c
PS!or!m
return nFileLength; MR4k#{:w
} '.%Omc
EUrIh2.Z
,qB@agjvo<
//保存下载信息（文件指针位置） e+#k\x
private void write_nPos() Ht}?=ZzW
{ [q0^Bn}h
try{ ,bM):
output = new DataOutputStream(new FileOutputStream(tmpFile)); <h+UC# .x
output.writeInt(nStartPos.length); nRX'J5Q m<
for(int i=0;i<nStartPos.length;i++) (u@X5O(a
{ NyC&j`d
// output.writeLong(nPos); 2Kr8#_) 0
output.writeLong(fileSplitterFetch.nStartPos); 7;.Iat9gMf
output.writeLong(fileSplitterFetch.nEndPos); z&#^9rM"
} fWIWRsy%
output.close(); lOb(XH9
} -+2A@kmEJ
catch(IOException e){e.printStackTrace ();} 4%<wxrod
catch(Exception e){e.printStackTrace ();} G[`2Nd<
} B )\;Ja
qTWQ!
'O2/PU2_
//读取保存的下载信息（文件指针位置） aS>cXJ;=
private void read_nPos() ;U a48pSv
{ ?Ec{%N%
try{ C^_m>H3b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L"c.15\
int nCount = input.readInt(); e^;:iJS
nStartPos = new long[nCount]; E}0g
nEndPos = new long[nCount]; 1jBIi
for(int i=0;i<nStartPos.length;i++) ~-sG&u>
{ e*I92
nStartPos = input.readLong(); j-i>Jd7
nEndPos = input.readLong(); 6h&t%T
} \v{HjqVkC
input.close(); 5K&A2zC|
} }2c&ARQ.m>
catch(IOException e){e.printStackTrace ();} 3)e{{]6
catch(Exception e){e.printStackTrace ();} kQ2WdpZ/
} <dXeP/1w`
(6}7z+
:1"k`AG
private void processErrorCode(int nErrorCode) T^$`Z.
{ W"t^t|H'~
System.err.println("Error Code : " + nErrorCode); -I*vl
} ApggTzh@
>lJTS t5{
eqOT@~H
//停止文件下载 ^e\$g2).
public void siteStop() 9R-2\D]
{ d mTZEO
bStop = true; M,oZ_tY%
for(int i=0;i<nStartPos.length;i++) Ui1s]R
fileSplitterFetch.splitterStop(); dxS5-aWy9w
Cd6th F)
Uhn3usK
} y GmFi
} Jko=E
//负责部分文件的抓取 Bw+?MdS
**FileSplitterFetch.java <4zSh3
*/ fceO|mSz_
package NetFox; T>hm\!
XW2ZQMos1
5xj8^W^G9
import java.io.*; "So"oT1
import java.net.*; +RiI5.$=Z
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z/WGL
public class FileSplitterFetch extends Thread { X -=M>H^
c|k(_#\B
Ff =%eg]
String sURL; //File URL oxI?7dy5
long nStartPos; //File Snippet Start Position 7GErh,
long nEndPos; //File Snippet End Position &U([Wd?E2
int nThreadID; //Thread's ID BbL]0i
boolean bDownOver = false; //Downing is over =CdrhP_
boolean bStop = false; //Stop identical 6p&uifY}tR
FileAccessI fileAccessI = null; //File Access interface >b:5&s\9
|S<!'rY
%(K}1[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DH i@ujr
{ f|/ ,eP$
this.sURL = sURL; g"c7$
this.nStartPos = nStart; 2BT+[
this.nEndPos = nEnd; (_3'nFg
nThreadID = id; wQ9@ l
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LZ&I<ID`-
} udc9KuR@
1#fR=*ZM"
FGm!|iI
public void run() TnKOr~@*
{ hOFvM&$
while(nStartPos < nEndPos && !bStop) >r}?v3QW
{ }!|$;3t+c
>@-.rkd(
q]Xu #:X
try{ 6p3cMJ'8y
URL url = new URL(sURL); Y;E'gP-J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xh25 *y
httpConnection.setRequestProperty("User-Agent","NetFox"); i],~tT|P
String sProperty = "bytes="+nStartPos+"-"; 7A$mZPKh
httpConnection.setRequestProperty("RANGE",sProperty); O@dK^o
Utility.log(sProperty); -Edi"B4K
F|oyrG
[ `_sH\
InputStream input = httpConnection.getInputStream(); /t2H%#v{
//logResponseHead(httpConnection); *Utx0Me
k;SKQN
%503<j
byte[] b = new byte[1024]; B T {cTj0W
int nRead; 4N3O<)C)@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k$DRX)e
{ <QaUq`,
nStartPos += fileAccessI.write(b,0,nRead); w`M`F<_\:
//if(nThreadID == 1) RjrQDh|((
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7;r3Bxa Q
} 8$IUit h
Y~#F\v
>f1fvv6
Utility.log("Thread " + nThreadID + " is over!"); `JGW8 _
bDownOver = true; jzWgyI1b
//nPos = fileAccessI.write (b,0,nRead); #~qzaETv,
} fwUF5Y
catch(Exception e){e.printStackTrace ();} Zz'g&ewo
} `/i/AZ{
} WOeLn[
1L?W+zMO
8A-*MU`+
//打印回应的头信息 9.#")%_p
public void logResponseHead(HttpURLConnection con) #8BI`.t)j
{ R;&k/v
for(int i=1;;i++) hD,|CQ
{ D+q z`
String header=con.getHeaderFieldKey(i); Z^WI~B0nt
if(header!=null) CkV -L4Jq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r5$!41
Utility.log(header+" : "+con.getHeaderField(header)); VOg'_#I
else -?IF'5z
break; *{p:C
} N6A|
} xnw'&E
2<'ol65/c
:eevc7
public void splitterStop() R4DfqX
{ NMrf I0tbG
bStop = true; "st+2#{
} OKu~Nb*
Z\n^m^Z =
EF9Y=(0|
} |;p.!FO
iVmy|ewd
8R(l~
/* i;IhsKO0R
**FileAccess.java Nm%#rZrN~Q
*//文件访问(定位，写) 66_=bd(9
package NetFox; |X6R2I
import java.io.*; Rz*GRe
6 lEv<)cC
z|(<Co8#.
public class FileAccessI implements Serializable{ QXy=|
~9;udBfwF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tk:G6Bkid
RandomAccessFile oSavedFile; Bcb '4*:
long nPos; qamq9F$V
"zqa:D26
[l<&eI&ln
public FileAccessI() throws IOException A2P.5EN
{ 1jPh0?BY
this("",0); l=$?#^^ /
} 5rQu^6&
KAu>U3\/
>5Y.
public FileAccessI(String sName,long nPos) throws IOException 2nL*^hhh
{ TDy$Mv=y
oSavedFile = new RandomAccessFile(sName,"rw"); WWOjck#
this.nPos = nPos; :j/sTO=
oSavedFile.seek(nPos); (>lH=&%zj
} OcC|7s",
=OTu8_ d0t
G6JP3dOT
public synchronized int write(byte[] b,int nStart,int nLen) Y&DoA0/y
{ # |OA>[
int n = -1; )6o%6$c
try{ wuSotbc/
oSavedFile.write(b,nStart,nLen); 6/"#pe^
n = nLen; `/B+
} z+zEH9.'
catch(IOException e) }-9 c1&m
{ y*=Ipdj
e.printStackTrace (); VG50n<m9
} zpzxCzU
Z=a~0&G
g!cW`B'
return n; T&Z*=ShH
} d(KK7SQg
g{K \
m)r,
} j;-2)ZLm
]U}B~Y
KUHkjA_
/* Dg}EI^ d
**SiteInfoBean.java |nqN95'u+]
*/ 4.~<|T8
package NetFox; 3'SN0VL
,TYFPulYcp
qT#NS&T!-
public class SiteInfoBean { MfdkvJ'
K@:t6
]xbMMax
private String sSiteURL; //Site's URL pP#|: %
private String sFilePath; //Saved File's Path ~|LAe-e"
private String sFileName; //Saved File's Name Eb5BJ-XeS^
private int nSplitter; //Count of Splited Downloading File )Z\Zw~L
/2tPd
J?hs\nA
public SiteInfoBean() +NeoGnj
{//nSplitter的缺省值为5 $)6M@S
//default value of nSplitter is 5 Wo,93]
this("","","",5); 0;4 YU%u
} nu2m5RYx
TnQW~_:
l701$>>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w")m]LV
{ z&jASL
sSiteURL= sURL; ~b4kV)[ q
sFilePath = sPath; `-?`H>+OG
sFileName = sName; N-45LS@
this.nSplitter = nSpiltter; b8Hzl!zO
4`Jf_C
J]Rh+@r.
} lfr^NxOU
E;q+u[$
sG^{ cn
public String getSSiteURL() C@pn4[jTl
{ OXB 5W#$
return sSiteURL; *R7bI?ow
} d vo|9>
lB!M;2^)X
gQ<{NQMzvd
public void setSSiteURL(String value) Xxj<Ai2
{ d\8j!F^=
sSiteURL = value; TFzk5
} ~c*kS E2X
T#vY(d
Rv.IHSQUo
public String getSFilePath() vV"I}L
{ QcjsQTAbk
return sFilePath; %Z-xh<&
} c}H}fyu%n
@twi<U_
"EE(O9q
public void setSFilePath(String value) #<#-Bv
{ 9 aKU}y
sFilePath = value; b~<:k\EE
} Zb'a+8[
abS3hf
YtXd>@7
public String getSFileName() ~&"'>C#
{ }j!C+i
return sFileName; /-(OJN5F^
} 05 .EI)7
R0bgt2J
AOz~@i^
public void setSFileName(String value) ~4xn^.w
{ J*AYZS-tSE
sFileName = value; kxmsrQ>av
} Z>dvth
yQ&C]{>TS
_x$\E
public int getNSplitter() #F6M<V'
{ ,vBB". LY'
return nSplitter; d ]#`?}
} /J(~NGT
l%qh^0
by$mD_sr
public void setNSplitter(int nCount) \tP*Pz
{ NceK>::56
nSplitter = nCount; AKS. XW
} #RKd>ig%
} Ds{DVdqA$c
LCe6](Z
57_AJT hR
/* Ri*mu*r\}
**Utility.java Owv}lJ
*/ WHu[A/##']
package NetFox; JIf.d($ ~:
8x8nQ*_
ll?Qg%V[t
public class Utility { Nk1p)V SC
PO|gM8E1x?
cE?p~fq<
public Utility() r[#*..Y
{ 0W~1v
L(C0236r
f>m! }F:
} #IJ6pg>K
/03?(n= 3
//线程睡眠 NL'(/|)
public static void sleep(int nSecond) {s=c!08=
{ ^S(QvoaQ
try{ DU-dIqi
Thread.sleep(nSecond); o@L '|#e
} (?i4P5s[!
catch(Exception e) e488}h6#m
{ K 28s<i`
e.printStackTrace (); (-@I'CFd
} KHM,lj*
} SPauno <M
v|@EuN14<
//日志 klTRuU(
public static void log(String sMsg) cqcH1aSv
{ '>Thn{
System.err.println(sMsg); n8FIxl&u
} F|P?|
r&~]6 U
<)"2rxX&5
public static void log(int sMsg) *zdUCX
{ O8-Z >;
System.err.println(sMsg); a%QgL&_5
} anORoK.
} u]]mbER*t#
M[e^Z}w.V
JZE<oQ_Jm
/* gj&5>brP
**TestMethod.java shiw;.vR{B
*/ 6t'.4SR
package NetFox; -67!u;
3@1$y`SN
G$*z4@Gz
public class TestMethod { dki3(
^Of\l:q*
g``S SU
public TestMethod() c4bvJy8
{ ///xx/weblogic60b2_win.exe 7Oi<_b
try{ 7'ws: #pC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -<tTT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Vygh|UEo
SiteFileFetch fileFetch = new SiteFileFetch(bean); Gc;-zq
fileFetch.start(); nk;+L
} j|b$b,rF\
catch(Exception e){e.printStackTrace ();} $2'+R
Z}3;Ych
wp@6RJ
} kc2 8Q2
jV<5GWq
}s8xr>
public static void main(String[] args) R?J8#JPXD
{ {@PZlQg
new TestMethod(); Ij9=J1c4
} v7D0E[)~
} Vq^b_^
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