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)); (BQ3M-
} s /q5o@b{
for(int i=0;i<nEndPos.length-1;i++) TdIFZ[<7
{ v oS"X
nEndPos = nStartPos[i+1]; GJ_)Cl+5E
} ~@?-|xLqQ
nEndPos[nEndPos.length-1] = nFileLength; n)!_HNc9
} mXM>6>;y
} >MY.Fr#.m
17]31
qFChZ+3>
//启动子线程 % j{pz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; EI+/%.,
for(int i=0;i<nStartPos.length;i++) zd4y5/aoS
{ Z?aR9OTP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w*P4_= :%Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), yBh"qnOT
nStartPos,nEndPos,i); sq|@9GS0T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9<c4y4#y
fileSplitterFetch.start(); 'J0s%m|j
} Ngc+<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w$:)wyR-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =usDI<3r
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NKhR%H
nEndPos = " + nFileLength); #$B,8LFz,$
// fileSplitterFetch[nPos.length-1].start(); yzR=:0J
U`_vF~el~
)&!@O$RS8(
//等待子线程结束 E!l1a5qB
//int count = 0; 5GL+j%7
//是否结束while循环 G-?9;w'@
boolean breakWhile = false; !:[n3.vm
NRF%Qd8I/2
wggHUr(g,
while(!bStop) ?s} E<Kr
{ <@!kR$Rd
write_nPos(); `0sk2fn
Utility.sleep(500); nJH%pBc
breakWhile = true; (jFE{M$-
% peb{i
m1i$>9,
for(int i=0;i<nStartPos.length;i++) c} ET#2,
{ cNc_ n<M
if(!fileSplitterFetch.bDownOver) )K3 vzX
{ tg3JU\
breakWhile = false; IqKXFORiNI
break; pv SFp-:_
} o`! :Q!+
} Fe< t@W
if(breakWhile) JlGD.!`
break; Q&Ahr
rL3Vogw'e
(gB=!1/|G
//count++; bxe97]
//if(count>4) lD#1"$Coz
// siteStop(); i3j jPN!
} n(S-F g
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Q9zpX{JT
System.err.println("文件下载结束！"); %,D%Q~
} {5-{f=Rk
catch(Exception e){e.printStackTrace ();} S*s9?
} tah%jRfT&
=Fl4tY#X
wh+ibH}@!
//获得文件长度 6ng g*kE<
public long getFileSize() j&GKpt
{ K):sq{
int nFileLength = -1; :#jv4N
try{ .cog9H'
URL url = new URL(siteInfoBean.getSSiteURL()); &bu`\|V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `.WKU"To
httpConnection.setRequestProperty("User-Agent","NetFox"); 9GaER+d|
]%hI-
vUeel%
int responseCode=httpConnection.getResponseCode(); Bd[Gsns
if(responseCode>=400) gg_(%.>
{ x[6Bc
processErrorCode(responseCode); v"_#.!V
return -2; //-2 represent access is error 4FdH:os
} |JQKxvjT
RE$-{i
f L?~1i =
String sHeader; muY^Fx
L$Z_j()2
nzl,y,
for(int i=1;;i++) p:%E>K1<
{ ^ ?9 ~R"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ! NEq|Y
//Utility.log(in.readLine()); @$G K<jl
sHeader=httpConnection.getHeaderFieldKey(i); imQNfNm
if(sHeader!=null) '#6DI"vJ
{ z# B) b5
if(sHeader.equals("Content-Length")) 1bs95Fh9Q
{ iO`f{?b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bYH_U4b
break; }C#d;JC
} k"zHrn"$
} YaNVpLA
else x#j_}L!V;
break; O v6=|]cW
} Big-)7?
} M!'tD!NWc
catch(IOException e){e.printStackTrace ();} pl&GFf o
catch(Exception e){e.printStackTrace ();} kk#d-! $[
,1L^#?Q~
/VkJ+%}+j
Utility.log(nFileLength); o*'3N/D~
WU_Q 7%+QS
8+F2 !IM
return nFileLength; 5]JXXdt
} DLZ63'
5w3'yA<vE
omP7|
//保存下载信息（文件指针位置） 8/v_uEG
private void write_nPos() VZR6oia
{ :+$_(*Z
try{ 4R6 .GO
output = new DataOutputStream(new FileOutputStream(tmpFile)); i.&16AY
output.writeInt(nStartPos.length); j)Gr@F>
for(int i=0;i<nStartPos.length;i++) ccAEN
{ )\^OI:E
// output.writeLong(nPos); 7lu;lAAP
output.writeLong(fileSplitterFetch.nStartPos); gO36tc:ce
output.writeLong(fileSplitterFetch.nEndPos); 7\lc aC@
} :;QLoZh^
output.close(); [MG:Ym).2`
} m`aUz}Y>c
catch(IOException e){e.printStackTrace ();} JG4I-\+H
catch(Exception e){e.printStackTrace ();} l[Oxf|
} X3vrD{uNU
Uz_{jAhW]
L^}kwu#
//读取保存的下载信息（文件指针位置） QKxuvW
private void read_nPos() #a|5A:g%
{ 9AaixI
try{ **"sru;@=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $MHc4FE[
int nCount = input.readInt(); ww*F}}(
nStartPos = new long[nCount]; M:N>{_1&
nEndPos = new long[nCount]; UPsh Y
for(int i=0;i<nStartPos.length;i++) u#QQCgrs
{ O^GTPYW
nStartPos = input.readLong(); X.Kxio $o
nEndPos = input.readLong(); w*0T"hK
} h/ic-iH(>
input.close(); %' Fc%3
} 1Cthi[B
catch(IOException e){e.printStackTrace ();} Gf>T{Q`,is
catch(Exception e){e.printStackTrace ();} ;x"B ):?\
} 1Low[i
~QXNOtVsN
HU'}c*d]
private void processErrorCode(int nErrorCode) XUWza=BR"
{ #0tM88Wi
System.err.println("Error Code : " + nErrorCode); MwZ`NH|n3"
} nr}H;wB
aqlYB7
mz''-1YY$
//停止文件下载 ?*g]27f11
public void siteStop() 2C>PxA6l
{ $xqphhBg
bStop = true; F-t-d1w6
for(int i=0;i<nStartPos.length;i++) ~ lS3+H
fileSplitterFetch.splitterStop(); Z(FAQ\7
>r3Wo%F'
3ul
} {^v50d
} (fl2?d5+C
//负责部分文件的抓取 rmhB!Lo
**FileSplitterFetch.java Sc(2c.HO*
*/ u:k#1Nn!
package NetFox; 59LIK&w
iJAW| dw}
h$3Y,-4
import java.io.*; @/~41\=e
import java.net.*; qe0@tKim
,}<v:!
/#HY-b
public class FileSplitterFetch extends Thread { 2w%1\TcB$
HV>Wf"1
&p*N8S8
String sURL; //File URL MTQdyTDHl
long nStartPos; //File Snippet Start Position p 7sYgz
long nEndPos; //File Snippet End Position r\yj$Gu>(
int nThreadID; //Thread's ID (jXgJ" m
boolean bDownOver = false; //Downing is over ?tOzhrv
boolean bStop = false; //Stop identical &*0V!+#6
FileAccessI fileAccessI = null; //File Access interface WWY9U
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phTZUmi
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rv^j&X+EH
{ *fx<>aK
this.sURL = sURL; dW91nTQ:
this.nStartPos = nStart; [KJm&\evp
this.nEndPos = nEnd; JprZ6 >
nThreadID = id; jtA Yp3M-$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 St?vd+(>
} h/X),aK3
aJ2-BRn
}[1I_)
public void run() Z0x N9S
{ 7oUYRqd
while(nStartPos < nEndPos && !bStop) *l|CrUa
{ BPW:W }
Ts^IA67&<
H|Eu,eq-E
try{ _3`{wzMA
URL url = new URL(sURL); b2z~C{l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ";Lpf]<
httpConnection.setRequestProperty("User-Agent","NetFox"); <yeG0`}t
String sProperty = "bytes="+nStartPos+"-"; :R_(+EK1
httpConnection.setRequestProperty("RANGE",sProperty); pNDL:vMWP
Utility.log(sProperty); 3ZC[H'|
7;Wj^#
Hkpn/,D5
InputStream input = httpConnection.getInputStream(); U,/>p=s
//logResponseHead(httpConnection); q4VOK 'N
LJT+tb?K
' e-FJ')|
byte[] b = new byte[1024]; QkA79%;j
int nRead; o zv><e#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Lq yY??\@
{ XI pXP,Yy
nStartPos += fileAccessI.write(b,0,nRead); ;i1H {hB
//if(nThreadID == 1) iNha<iS+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <^M`U>
} 1Azigd0%
xl s_g/Q
R#gip
Utility.log("Thread " + nThreadID + " is over!"); nF05p2Mh
bDownOver = true; {>Zc#U'
//nPos = fileAccessI.write (b,0,nRead); IF uz'
} Z$T1nm%lo:
catch(Exception e){e.printStackTrace ();} ;]|Z8#s
} RTSg=
} G<$UcXg
JGJQ5zt
@>JO &,od
//打印回应的头信息 H!,#Z7s
public void logResponseHead(HttpURLConnection con) m"`&FA
{ <s $~h
for(int i=1;;i++) d!8`}L:=M
{ ]XU?Wg
String header=con.getHeaderFieldKey(i); Cdc6<8
if(header!=null) 1}9@aKM
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D guAeK
Utility.log(header+" : "+con.getHeaderField(header)); eEXer>Rm
else Q[S""P.Z|
break; 9"oc.ue.2D
} Wl}d6ZTm
} ~c+0SuJ
&+u$96
x# 0(CcKK
public void splitterStop() GV* B$
{ 59IxY ?
bStop = true; J'|qFS
} 5|";L&`
EG2NE,,r
eQNo'cz
} rm<(6zY
g6+}'MN:5
GRS[r@W[1
/* Zn|vT&:Hg
**FileAccess.java <T{PuS1<o
*//文件访问(定位，写) "^yTH/m
package NetFox; g*TAaUs|n
import java.io.*; 6;k#|-GU&
$s$z"<
* 3WK`9q
public class FileAccessI implements Serializable{ \5cAOBja
._Wm%'uX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z25^+)uf*U
RandomAccessFile oSavedFile; pS;jrq I#
long nPos; j-ZKEA{:1
I HgYgn
5Jlz$]f
public FileAccessI() throws IOException tUH#%
{ ~Qeyh^wo
this("",0); kTt;3Ia
} q3#07o_dV
ORD@+ {
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public FileAccessI(String sName,long nPos) throws IOException XOAZ
{ ]^uO3!+
oSavedFile = new RandomAccessFile(sName,"rw"); LSS3(l[,:
this.nPos = nPos; R&PQU/t)
oSavedFile.seek(nPos); 4Bsx[~ u&
} 8xW_N"P.>
Tl6%z9rY@
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public synchronized int write(byte[] b,int nStart,int nLen) )<nr;n
{ !c(B c^
int n = -1; 3V>2N)3`A
try{ 1-!u=]JDE
oSavedFile.write(b,nStart,nLen); :''^a
n = nLen; ~m2tWi@
} "9:1>Gr{G
catch(IOException e) #XE`8$
{ E=+v1\t)]
e.printStackTrace (); a=>PGriL
} Ew~piuj
3iMh)YH5b
sg RY`U.C
return n; ZnVi.s~1V
} pj4M|'F7
5B)Z@-x2
I@76ABu^
} zc%#7"FM
,#@B3~giC
: z*OAl"
/* 3R>U^ Y
**SiteInfoBean.java }D-h=,];
*/ pHSq,XP-
package NetFox; ()i8 Qepo}
R/&Bze
,{!~rSq-l
public class SiteInfoBean { Z<T%:F
Ke@zS9
Ju4={^#
private String sSiteURL; //Site's URL Lwm2:_\_b
private String sFilePath; //Saved File's Path cPZD#";f
private String sFileName; //Saved File's Name Rrmk\7/
private int nSplitter; //Count of Splited Downloading File :yO.Te F
u^&2T(xGi
P]hS0,sE<(
public SiteInfoBean() h)2W}p{a4=
{//nSplitter的缺省值为5 dP}=cZ~
//default value of nSplitter is 5 KAH9?zI)M
this("","","",5); 2A'!kd$2
} U`Bw2Vdk]S
oju)8H1o#
Yz4)Q1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MM8@0t'E
{ R%B"Gtl)
sSiteURL= sURL; A82Bn|J
sFilePath = sPath; hqOy*!8'@
sFileName = sName; w],+lN;
this.nSplitter = nSpiltter; Y?G\@6
$J}d6%
@y?<Kv}s
} &0! f_
4Rj;lAlwB
s}yJkQb
public String getSSiteURL() #~<cp)!3
{ %6rMS}
return sSiteURL; ,[fn? s r
} Nb;xJSlox
l,5<g-r V
l+g\xUP
public void setSSiteURL(String value) ?`T< sk8c
{ :KY920/,
sSiteURL = value; )*<=:
} $h"Ht2/ J
CGmObN8~'F
U,Py+c6
public String getSFilePath() Teq1VK3Hr
{ CFdR4vuEI
return sFilePath; a![x^@nF
} =xzDpn>f
z/09~Hc
DL0jA/f
public void setSFilePath(String value) )9LlM2+y
{ hwgLJY?
sFilePath = value; ~a@O1MB
} 1 ?X(q
S ykblP37
6;"^Id
public String getSFileName() ;\~{79c
{ TTB1}j+V6
return sFileName; 8/lv,m#
} "]*16t%Z%x
2E]SKpJ
EAiE@r>4
public void setSFileName(String value) sbnNk(XINQ
{ }2dz];bR
sFileName = value; Bc1[^{`bq^
} bMWL^*I
Gd^K,3:. T
LvP{"K;
public int getNSplitter() |KSd@
{ Fh t$7V
return nSplitter; Z#H] yG
} q:2Vw`g'
9v[cy`\
cTpmklq
public void setNSplitter(int nCount) /B>p.%M[&
{ 8$Igo$U-
nSplitter = nCount; FCO5SX#-g
} 7+^9"k7
} F<SCW+>z2a
ma4Pmk
[Y@?l]&
/* +%yVW f
**Utility.java !YUMAp/
*/ ] Tc!=SV
package NetFox; H"v3?g`S%
/>1Ndj
7)Zk:53]
public class Utility { 43_;Z| T
q:Lw!'Zh
N^i<A2'6S;
public Utility() }~gBnq_DDU
{ S0X%IG
s"1:#.u
"r@f&Ssxb
} G55-{y9Q
B_;W!
//线程睡眠 BI9~%dm
public static void sleep(int nSecond) 77y_?di^I
{ SCbN(OBN!
try{ z=ItKoM*<
Thread.sleep(nSecond); MF+J3)
} ~lB im$o
catch(Exception e) Yt^<^l77D
{ ym*,X@Qg^
e.printStackTrace (); (#zSVtZ
} Rx';P/F0C
} R7'a/
Vp3r
//日志 |Ld/{&Qr
public static void log(String sMsg) vfb~S~|U6g
{ B(}u:[ b^S
System.err.println(sMsg); i1ph{;C
} &V.ps1
F_8< tA6
.}KY*y
public static void log(int sMsg) 8J60+2Wa
{ #ma#oWqF}
System.err.println(sMsg); +h!OdWD9
} jVh I`F{n
} {/f\lS.5g
FmU>q)
8u+FWbOl]
/* B o@B9/ABv
**TestMethod.java y\}39Z(]
*/ REd"}zDI
package NetFox; ?QzA;8H
Z#8O)GK
YyI4T/0s_
public class TestMethod { b"`Vn,
:mwNkT2et
qw]:oh&G
public TestMethod() lWYZAF>?Ym
{ ///xx/weblogic60b2_win.exe &[]0yNG
try{ Fi8'3/q-^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `Qzga}`"]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3Q-i%7l
SiteFileFetch fileFetch = new SiteFileFetch(bean); hdFIriE3
fileFetch.start(); 6>I{Ik@>
} ] i;xeo,
catch(Exception e){e.printStackTrace ();} .(!> *ka|
U p1&(
y@&Cn
} rh;@|/<l
u&Ze$z
fX)C8J^=G
public static void main(String[] args) [K2\e N~g
{ k0;ND
new TestMethod(); }Qjp,(ye
} 76i)m!
} Nr.maucny
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