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)); p[0Ws460
} $sU?VA'h
for(int i=0;i<nEndPos.length-1;i++) =P'=P0G
{ !}"npUgE
nEndPos = nStartPos[i+1]; ]b'K BAMy
} iEr|?,
nEndPos[nEndPos.length-1] = nFileLength; 7_S+/2}U*
} $P^=QN5Bb
} Xr:"8FT
N ]}Re$5
X-3L4@T:?
//启动子线程 R=i$*6}a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (*/P~$xIj
for(int i=0;i<nStartPos.length;i++) s$C;31k
{ 9$~D4T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Aw4Qm2Kf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m/0G=%d%k
nStartPos,nEndPos,i); g"2@E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *Sz`=U7n
fileSplitterFetch.start(); <!y_L5S|
} .W,<]L '
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A{>]M@QC2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); izY,t!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f4/!iiS}r
nEndPos = " + nFileLength); }.NR+:0
// fileSplitterFetch[nPos.length-1].start(); 18}L89S>
bsr
(^qcX;-
//等待子线程结束 *7ap[YXZ\w
//int count = 0; #E^%h
//是否结束while循环 pP{b!1
boolean breakWhile = false; e:AB!k^xp$
>7vSN<w~m
-hQ=0h~\B.
while(!bStop) 7vNS@[8
{ T(a*d7
write_nPos(); O_-.@uo./(
Utility.sleep(500); OA%.>^yb@
breakWhile = true; g[8VfIe
i2N*3X~
Lg9]kpOpa
for(int i=0;i<nStartPos.length;i++) K.o?g?&<
{ !h?N)9e
if(!fileSplitterFetch.bDownOver) bp_3ETK]P
{ /P^@dL
breakWhile = false; q<oA%yR
break; </bWFW~x
} ~ZG>n{Q
} K._1sOw'"Y
if(breakWhile) ,{J2i#g<
break; _=UXNr8S
EIEwrC
{4}Sl^kn*
//count++; 6@H&S
//if(count>4) |8`}yRsQ
// siteStop(); [DGq{(O
} A"vI6ud>
- CM;sXq
WVy"MD
System.err.println("文件下载结束！"); P/nXY
} Sl:\5]'yJ
catch(Exception e){e.printStackTrace ();} -/#3U{O
} b'3#FI=:
MMhd-B1O&
$N,9e
//获得文件长度 YlPZa3\
public long getFileSize() ?Z1pPd@
{ f,t[`0 va
int nFileLength = -1; ut3jIZ1]
try{ wKk
URL url = new URL(siteInfoBean.getSSiteURL()); .IF dJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A javV
httpConnection.setRequestProperty("User-Agent","NetFox"); 5:iril
(ter+rTv
O-|RPW}
int responseCode=httpConnection.getResponseCode(); CdWGb[uI
if(responseCode>=400) Q>TaaGc
{ <@F4{*
processErrorCode(responseCode); OX8jCW
return -2; //-2 represent access is error Q{>9Dg
} p&vQ*}
y,Dfqt
N#T MU
String sHeader; ~+CNED0z+
8f8+3
KO{}+~,.6
for(int i=1;;i++) Kz$Ijj
{ +Tq _n@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xU@Z<d,k
//Utility.log(in.readLine()); -{7:^K[)
sHeader=httpConnection.getHeaderFieldKey(i); ^$?8!WE
if(sHeader!=null) 7-^df0
{ <408lm
if(sHeader.equals("Content-Length")) yv$MQ~]
{ y)s/\l&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ZJR{c5TE
break; lFc3 5
} V#3VRh
} 2$T~(tem
else WY*}|R2R
break; )}?dYk
} !my5-f>{(
} 9]AKNQq m
catch(IOException e){e.printStackTrace ();} Ir0er~f+z
catch(Exception e){e.printStackTrace ();} Ty@&s58a
:Bn\1\
D+ jk0*bJ
Utility.log(nFileLength); {qOSs,+=L
T}u'
1$Eiv8xd
return nFileLength; l#Qf8*0
} }$$b6G
@B&hR} 4
ISq^V
//保存下载信息（文件指针位置） ]'M4Unu#@
private void write_nPos() W@UHqHr:\
{ WZFV8'
try{ fl)Oto7
output = new DataOutputStream(new FileOutputStream(tmpFile)); PN\2 ^@>_
output.writeInt(nStartPos.length); j$8~M
for(int i=0;i<nStartPos.length;i++) Gi{1u}-0
{ J+.t\R
// output.writeLong(nPos); hp>me*vzr
output.writeLong(fileSplitterFetch.nStartPos); a,}{f]
output.writeLong(fileSplitterFetch.nEndPos); r@ejU'uz
} 8,['q~z
output.close(); @|d|orMC
} -Tz9J4xU&
catch(IOException e){e.printStackTrace ();} ZnmBb_eX
catch(Exception e){e.printStackTrace ();} r*tGT_/6
} 2t(E+^~
> }:6m
}F1^gN&QF
//读取保存的下载信息（文件指针位置） zA+^4/M
private void read_nPos() ?cpID8Z
{ !).D
try{ 3}N:oJI$z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Kt`0vwkjvI
int nCount = input.readInt(); E~N}m7kTl/
nStartPos = new long[nCount]; =)y=M!T2
nEndPos = new long[nCount]; ;)clCm46
for(int i=0;i<nStartPos.length;i++) yq&]>ox
{ @Z|cUHo
nStartPos = input.readLong(); A Ys<IMQ
nEndPos = input.readLong(); e@I?ESZ5
} 7J')o^MG
input.close(); IHB{US1G
} ?;i6eg17<
catch(IOException e){e.printStackTrace ();} RS$:]hxd>_
catch(Exception e){e.printStackTrace ();} hVR=g!e#X
} X59~)rH,
szKs9er&
'X[3y^q
private void processErrorCode(int nErrorCode) \wnQ[UNjP
{ p\!+j@H:
System.err.println("Error Code : " + nErrorCode); O #0:6QX
} UQhfR}(
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U` bvv'38#
//停止文件下载 pX2 Ki^)]
public void siteStop() a{H~>d<?
{ o3uv"# C
bStop = true; 2I#fwsb
for(int i=0;i<nStartPos.length;i++) mNuv>GAb
fileSplitterFetch.splitterStop(); *.Kc-f4mP
:uMD$zF'5
8-+IcyUza
} -5E%f|U
} B04Br~hel*
//负责部分文件的抓取 w"aD"}3
**FileSplitterFetch.java 3RGVH,
*/ Nf3Kz#!B
package NetFox; cG^'Qm
rJg!2
Ai/ay# E
import java.io.*; P'FI'2cN7
import java.net.*; GJH6b7I
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bup;4~g
public class FileSplitterFetch extends Thread { D^f;dT;-
! .!qJ%
<.=
String sURL; //File URL F lbL`@4M
long nStartPos; //File Snippet Start Position B"8^5#t4s
long nEndPos; //File Snippet End Position %>pglI
int nThreadID; //Thread's ID *<BasP
boolean bDownOver = false; //Downing is over XhTp'2,]
boolean bStop = false; //Stop identical ~>+}(%<,
FileAccessI fileAccessI = null; //File Access interface 0y6nMI
2MJ0[9
J *^|ojX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]D<r5P%
{ x{IOn;>R
this.sURL = sURL; /G</ [N5
this.nStartPos = nStart; whRc YnJ
this.nEndPos = nEnd; |\elM[G"g
nThreadID = id; wUl}x)xo
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9jJ&QACn
} DJ=miJI'
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public void run() ;m7$U
{ ~|fd=E%
while(nStartPos < nEndPos && !bStop) g.&&=T
{ |J~;yO SD
>#xpg&2x
iPI6 _h
try{ >\KBXS}
URL url = new URL(sURL); syV&Ds)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 22(0Jb\_
httpConnection.setRequestProperty("User-Agent","NetFox"); nh,N(t9
String sProperty = "bytes="+nStartPos+"-"; QT?fp >'
httpConnection.setRequestProperty("RANGE",sProperty); ZJI|762,
Utility.log(sProperty); Xgop1
X}g!Lp
t0Ec`+)
InputStream input = httpConnection.getInputStream(); {:'eH
//logResponseHead(httpConnection); ^Cpvh}1#
<Gs)~T#'
e7 5*84
byte[] b = new byte[1024]; mltN$b%G=d
int nRead; oIX]9~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t'FY*|xk
{ /__we[$E
nStartPos += fileAccessI.write(b,0,nRead); [T !#s
//if(nThreadID == 1) Q%q_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a?&oOQd-iP
} jC<<S
glPOW
S9-K
Utility.log("Thread " + nThreadID + " is over!"); E^Q|v45d
bDownOver = true; |o=eS&)
//nPos = fileAccessI.write (b,0,nRead); ^tae (}
} h6la+l?x
catch(Exception e){e.printStackTrace ();} cfpP?
} ^;Ap-2Ww
} ;o"}7'4*R%
O_(/uLH
[ @&
//打印回应的头信息 j9%=8Dn.<
public void logResponseHead(HttpURLConnection con) uppA`>
{ #ZF|5r +
for(int i=1;;i++) Dj #G{X".
{ :+m|KC(Z
String header=con.getHeaderFieldKey(i); 7BdvJ"
if(header!=null) Cc/?-0a2!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o= N=W
Utility.log(header+" : "+con.getHeaderField(header)); ~kw[Aw3?D\
else -=O9D-x=
break; `'.u$IBW
} )!){4c/
} l9?]t;
!,INrl[
~h tV*R
public void splitterStop() |"vqM)V$
{ Y0aO/6
bStop = true; l`fjz-eE
} h#'(UZ
1}BW
mgh,)=2cE(
} }3 RqaIY}
=w_y<V4
X=mzo\Aos
/* +n9]c~g!T0
**FileAccess.java bgL`FW i3
*//文件访问(定位，写) )z$VQ=]"
package NetFox; uFL~^vz
import java.io.*; 7*~ rhQ
w\8grEj
7AHEzJh"
public class FileAccessI implements Serializable{ pZ%/;sxYa
asmMl9)(`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T6%*t#8r
RandomAccessFile oSavedFile; D=o9+5Slw
long nPos; eHm!
,]42v?
91}QuYv/_
public FileAccessI() throws IOException ! E#XmYhX=
{ bu,Z'
this("",0); VQ{}S $jQ
} thl{IU
d]$z&E
|:L<Ko
public FileAccessI(String sName,long nPos) throws IOException _:?)2NV
{ ]aXCi"fMs
oSavedFile = new RandomAccessFile(sName,"rw"); 8'@pX<
this.nPos = nPos; W2qW`Ujo{
oSavedFile.seek(nPos); -U'6fx) +
} L&][730
z?Hvh
4:y;<8+j\
public synchronized int write(byte[] b,int nStart,int nLen) q --NLm@;
{ w<.{(1:v
int n = -1; 9{^:+r
try{ 0^?(;AK
oSavedFile.write(b,nStart,nLen); n!~{4 uUW
n = nLen; 9 k)?-
} oslV@v F
catch(IOException e) )g(2xUk-y
{ 0bzD-K4WVd
e.printStackTrace (); -r_z,h|
} ;.'2ZNt2
v%VCFJ
VSc;}LH
return n; B=JeZMn
} %o.{h
GL(R9Y
c{ +Y$
} xoA\^AA
4Fgy<^94`
xbxU`2/
/* q]`XUGC
**SiteInfoBean.java 3^xTZ*G
*/ k?o(j/
package NetFox; I)U|~N
.ss/E
j$4Tot
public class SiteInfoBean { @=E@ *@g
hS OAjS
#O7|&DqF{
private String sSiteURL; //Site's URL aqK<}jy
private String sFilePath; //Saved File's Path iL\<G} I
private String sFileName; //Saved File's Name &$ia#j{l
private int nSplitter; //Count of Splited Downloading File aF;QSI
-^Baxkq(YM
\=?f4*4|/
public SiteInfoBean() L!|c: 8
{//nSplitter的缺省值为5 XwOj`N{!H
//default value of nSplitter is 5 o6P)IZ1
this("","","",5); M@[{j
} MW &iNioX
Q4JwX=ZVj
5#p [Q _
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .36z
{ rg]eSP3W
sSiteURL= sURL; T+8F'9i`
sFilePath = sPath; ?dVF@
sFileName = sName; T_lexX[\
this.nSplitter = nSpiltter; (x2I*<7P
5 S$*YRp
4(B{-cK
} ?{mFQ
N1jj\.nB
%u-l6<w#R
public String getSSiteURL() #*:y2W%H
{ ]d&6 ?7 !>
return sSiteURL; w&8gA[y*u
} {n2mh%I
!G.)%+Z
Y.Na9&-(
public void setSSiteURL(String value) n{J<7I e"*
{ '-p<E"#4Z
sSiteURL = value; ]O3[Te
} yk5-@qo
4nzUDeI3MG
s(q\!\FS
public String getSFilePath() V/j+Z1ZW
{ <v&>&;>3
return sFilePath; R;,+0r^i
} }rz}>((ZHF
yHT8I
@]":3
public void setSFilePath(String value) ( ?3 )l
{ [~,~ e
sFilePath = value; y&")7y/uE
} J 6U3}SO=y
u* G|TF
ev7Y^
public String getSFileName() |_{-hNiz0
{ y,v*jE
return sFileName; Lj6$?(x}
} ~rN~Ql%S
bm*Ell\a.
C s?kZ %
public void setSFileName(String value) i=#<0!m
{ 'Pk ( 1:
sFileName = value; ^CX=<
} W2J"W=:z
}bz v&k
X3 D(2W
public int getNSplitter() MYFRrcu;
{ glbU\K> >
return nSplitter; % zHsh
} -bdF=
WBLfxr
D|} y{~
public void setNSplitter(int nCount) by,"Orpwq;
{ 23BzD^2a
nSplitter = nCount; SsiAyQ|Ma
} Z6\OkD
} (dvCejc^p
"l6v[yv
xG@zy4
/* [vV]lWOp'
**Utility.java w?|gJ*B"
*/ WDNuR#J?
package NetFox; =t\HtAXn[
$q);xs
+K,]#$k
public class Utility { P#]%C
%b<cJ]F
?NoG.
public Utility() G]X72R?g
{ E+k#1c|v$
i9+(gX(t
#G%[4.$n.
} _"%mLH=!8
TC;2K,.#k
//线程睡眠 ,rx?Ig}kz
public static void sleep(int nSecond) gTcLS|&H
{ 9E~=/Q=
try{ #u`i4
Thread.sleep(nSecond); (9$z+Zmm?
} MX2Zm
catch(Exception e) //S/pCqED
{ NPF"_[RoeV
e.printStackTrace (); BWV)> -V
} YYwFjA@
} Ugzq;}V#
-\xNuU
//日志 :1NF#-2\f
public static void log(String sMsg) Y4q;
{ ~'k.'O{
System.err.println(sMsg); musZCg$
} '|V"!R)
,\ [R\s
YMx]i,u'+
public static void log(int sMsg) M|nTO
{ VgLrufJ
System.err.println(sMsg); #lXwBfBMf
} :23w[vt=
} ".Z|zt6C
aGY R:jR$
( `T;nz
/* #m[R1G#
**TestMethod.java s>hNwb/
*/ *\><MXx
package NetFox; 8i"v7}
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;G_{$)P.o
public class TestMethod { CR3<9=Lv>
YQGVQ[P
OOJg%y*H
public TestMethod() ?T]3I.3 2^
{ ///xx/weblogic60b2_win.exe ?Co)7}N
try{ 1P i_V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "@uKe8r|y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &-M>@BMy
SiteFileFetch fileFetch = new SiteFileFetch(bean); Bc{j0Su
fileFetch.start(); sI>I
} &f48MtE
catch(Exception e){e.printStackTrace ();} [H ^ktF
/Ilve U`E
6Q\0v
} gD`|N@W$5
{}>s0B
i[,9hp
public static void main(String[] args) }o^VEJc`O
{ KU:RS+,e;
new TestMethod(); mN+ w,
} TKJs'%Q7F6
} IqEE.XhaK
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