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)); BQH}6ueZ
} F[ ajOb8
for(int i=0;i<nEndPos.length-1;i++) =3ioQZ^Vz
{ _5 ^I.5Z3
nEndPos = nStartPos[i+1]; %V9ZyQg%*
} <_Z:'~Zp
nEndPos[nEndPos.length-1] = nFileLength; 7Z ;?b0W
} ^O(=Vry
} {--0z3n>
U6E\AvbRn
a, Q#Dk
//启动子线程 ZK;zm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fA/m1bYxg
for(int i=0;i<nStartPos.length;i++) (Rt7%{*
{ mm[2wfTE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %p^.|Me7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'H5M|c$s
nStartPos,nEndPos,i); GeszgtK{T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2d%}- nw
fileSplitterFetch.start(); k3?rp`V1
} ;W>Cqg=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RlT3Iz;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ML;*e"$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OU5*9_7.
nEndPos = " + nFileLength); ,)PiP/3B
// fileSplitterFetch[nPos.length-1].start(); jHN +5=l
-HSs^dP`
O$/o'"@ /
//等待子线程结束 r(d':LV
//int count = 0; 5DOBsf8Jo
//是否结束while循环 y[B>~m8$
boolean breakWhile = false; HK\~Qnq
~'37`)]z
\`V;z~@iA
while(!bStop) #mize
{ H]4Hj
write_nPos(); KL$bqgc(p3
Utility.sleep(500); ^7zu<lX
breakWhile = true; .#02 ngh
['8!qr
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for(int i=0;i<nStartPos.length;i++) xGTP;NT_H
{ ljl^ GFo
if(!fileSplitterFetch.bDownOver) `.s({/|[
{ z'T)=ycT
breakWhile = false; V%$/#sza
break; v8AS=sY4r
} .920{G?l5
} bR@p<;G|
if(breakWhile) ]smkTo/
break; qC F5~;7
][}0#'/mV
{*{Ox[Nh{
//count++; Eu"_MgD
//if(count>4) 'y8]_K*
// siteStop(); L "sO+4w
} )95f*wte
p<=$&*
{(r6e
System.err.println("文件下载结束！"); *CHI2MB
} dy_:-2S
catch(Exception e){e.printStackTrace ();} =zQN[
} ;WR,eI..
Ft}@1w5
9tF9T\jW
//获得文件长度 #o1=:PQaC
public long getFileSize() : ]C~gc
{ (#+^&1
int nFileLength = -1; TB0 5?F
try{ !K|5bK
URL url = new URL(siteInfoBean.getSSiteURL()); mI74x3 [
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SlsdqP 9
httpConnection.setRequestProperty("User-Agent","NetFox"); oudxm[/U
lNSLs"x^
,VO2a mI
int responseCode=httpConnection.getResponseCode(); 8WnwQ%;m?
if(responseCode>=400) |sJSN.8
{ E>l~-PaZY
processErrorCode(responseCode); sQkhwMg
return -2; //-2 represent access is error oJN#C%r7
} 7uzkp&+:
kc0E%odF.v
|i++0BU
String sHeader; Ub6jxib
0_88V
(o`{uj{!
for(int i=1;;i++) A~-b!Grf
{ 2}8v(%s p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |\pbir
//Utility.log(in.readLine()); oq}'}`lw"
sHeader=httpConnection.getHeaderFieldKey(i); !qG7V:6
if(sHeader!=null) $|8!BOx8t
{ Jv^h\~*jH
if(sHeader.equals("Content-Length")) O%bEB g
{ vN;mPd~g
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); EFz&N\2
break; eA<0$Gs,h
} !KUi\yQ1
} #\=FO>
else % >=!p
break; B {>7-0
} ZHa"isl$e
} u?C#4
catch(IOException e){e.printStackTrace ();} wb0L.'jyR)
catch(Exception e){e.printStackTrace ();} WlU0:(d
VVlr*`
z4N*b"QF
Utility.log(nFileLength); wpN=,&!
q@{Bt{$x
GWfL
return nFileLength; LGn:c;
} }4,L%$@n
'dn]rV0(C
!z>6Uf!{
//保存下载信息（文件指针位置） 2'w?\{}D
private void write_nPos() ~sh`r{0
{ ?32&]iM oW
try{ }~L.qG
output = new DataOutputStream(new FileOutputStream(tmpFile)); E 7{U|\
output.writeInt(nStartPos.length); qi^7
for(int i=0;i<nStartPos.length;i++) ~A\GT$
{ 9iQq.$A.
// output.writeLong(nPos); F%RRd/'
output.writeLong(fileSplitterFetch.nStartPos); |!4K!_y
output.writeLong(fileSplitterFetch.nEndPos); 1eF3`
} .6Pw|xu`Pw
output.close(); 5?x>9Ca
} wfH^<jY)E
catch(IOException e){e.printStackTrace ();} r8RoE`/T
catch(Exception e){e.printStackTrace ();} Tc? $>'
} %$.3V#?
K|[*t~59
NPp;78O0[
//读取保存的下载信息（文件指针位置） 'd9INz.
private void read_nPos() %#kg#@z_`e
{ a!v1M2>
try{ t7aefV&_,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :/nj@X6
int nCount = input.readInt(); cPlZXf
nStartPos = new long[nCount]; H*PSR
nEndPos = new long[nCount]; ;{N!Eb`S
for(int i=0;i<nStartPos.length;i++) fumm<:<CLO
{ U2W|:~KM
nStartPos = input.readLong(); yd d7I&$
nEndPos = input.readLong(); \XZ/v*d0
} "~|6tQLc
input.close(); gi1^3R[
} .[ICx
catch(IOException e){e.printStackTrace ();} RMdk:YvBg
catch(Exception e){e.printStackTrace ();} Hquc o
} `r9!zffyS
Hx?;fl'G%
X aMJDa|M
private void processErrorCode(int nErrorCode) 3`DQo%<
{ g,!L$,/F
System.err.println("Error Code : " + nErrorCode); b gK}-EU
} u7>],<
yPb"V
!$gR{XH$]
//停止文件下载 GjvOM y
public void siteStop() N5lDS
{ 3YR!Mq$|~
bStop = true; 0AL=S$B)
for(int i=0;i<nStartPos.length;i++) p8Qk'F=h
fileSplitterFetch.splitterStop(); |v3T!
vdc\R?
gCB |DY
} @niHl
} Swig;`
//负责部分文件的抓取 s"r*YlSp"
**FileSplitterFetch.java vApIHI?-
*/ G[uK-U
package NetFox; (x;@%:3j$
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"R;U/+
import java.io.*; 8;RUf~q?
import java.net.*; K0|FY=#2y
W}@c|d $`
aC8} d
public class FileSplitterFetch extends Thread { C)ERUH2i
0z6R'Kjy A
KQ% GIz x
String sURL; //File URL 8Fz#A.%P
long nStartPos; //File Snippet Start Position z]_wjYn Z
long nEndPos; //File Snippet End Position {EB;h\C
int nThreadID; //Thread's ID vc;$-v$&
boolean bDownOver = false; //Downing is over *v!9MU9[(
boolean bStop = false; //Stop identical Z&+ g;(g
FileAccessI fileAccessI = null; //File Access interface 1Y\DJ@lh
6*78cg Io
2lH&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =(j1rW!
{ X9W@&zQ
this.sURL = sURL; un mJbY;t
this.nStartPos = nStart; hd%Fnykq
this.nEndPos = nEnd; l*(8i ^
nThreadID = id; &N^9JxN?8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BU/"rv"(Fg
} [Kg+^N%+
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;#W2|'HD
public void run() 2j[=\K]
{ c<:-T
while(nStartPos < nEndPos && !bStop) ~D j8z+^
{ l`lk-nb
].w4$OJ?
M6"PX *K
try{ !GjQPAW
URL url = new URL(sURL); iy.p n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BO?%'\
httpConnection.setRequestProperty("User-Agent","NetFox"); zZPO&akB"
String sProperty = "bytes="+nStartPos+"-"; nV|EQs4(
httpConnection.setRequestProperty("RANGE",sProperty); mp1@|*Sn
Utility.log(sProperty); Uiw2oi&_
3wF;GG
nfbR P t
InputStream input = httpConnection.getInputStream(); l ^0@86
//logResponseHead(httpConnection); @Md/Q~>
hR?{3d#x2
Mq156TL
byte[] b = new byte[1024]; hn GZ=
int nRead; e'NJnPO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) me$Z~/Akm
{ AlaW=leTe
nStartPos += fileAccessI.write(b,0,nRead); 5{X<y#vAC0
//if(nThreadID == 1) {UI+$/v#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y%cP1y)
} hED}h![
z\W64^'"Z
,]F,Uu_H7
Utility.log("Thread " + nThreadID + " is over!"); -l*|M(N\
bDownOver = true; &jJL"gq"
//nPos = fileAccessI.write (b,0,nRead); \;Biq`
} y'q$|
catch(Exception e){e.printStackTrace ();} AO4U}?
} ,?%Zc$\LW
} b4 6~?*
+Mb.:_7'
Rh{f5-
//打印回应的头信息 eF$x1|
public void logResponseHead(HttpURLConnection con) JGrWHIsNV
{ %$Tji
for(int i=1;;i++) m=:9+z
{ x=P\qjSa
String header=con.getHeaderFieldKey(i); By!o3}~g
if(header!=null) m+[Ux{$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c7k~S-nU
Utility.log(header+" : "+con.getHeaderField(header)); H/ HMm{4
else Ax7[;|2
break; lTgjq:mn
} IM'r8V
} K;G~V\
p8O2Z?\
:P~6~ Kum
public void splitterStop() x|Bf-kc[#Q
{ 1.GQau~
bStop = true; O,f?YJ9S
} <iC(`J$D
j</: WRA`]
g*_&
} T.BW H2gRP
A?P_DA
6%_nZvRv
/* UB@+ck
**FileAccess.java K+3=tk]W9u
*//文件访问(定位，写) +I|vzz`ZVr
package NetFox; KkbDW3-
import java.io.*; 7Ovi{xd@
hL{KRRf>
"ze|W\Bv!
public class FileAccessI implements Serializable{ .Yn_*L+4*
db7B^|Di
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g8% &RG
RandomAccessFile oSavedFile; #q=Efn'
long nPos; 583|blL
'-~~-}= sJ
dUZ ,m9u
public FileAccessI() throws IOException ;4|15S
{ <\^8fn
this("",0); }Zn}
} aX'*pK/-
sDlO#
aEeodA<(
public FileAccessI(String sName,long nPos) throws IOException Z@!+v19^
{ mz0X3
oSavedFile = new RandomAccessFile(sName,"rw"); hRhe& ,v
this.nPos = nPos; YNF k
oSavedFile.seek(nPos); <PH#[dH
} htF] W|z
`M8i92V\qY
^u ~Q/4
public synchronized int write(byte[] b,int nStart,int nLen) "+G8d'%YV
{ 9WyhZoPD*
int n = -1; W^l-Y%a/o
try{ &Ok):`
oSavedFile.write(b,nStart,nLen); oap4rHk}
n = nLen; `d}2O%P
} S.NPZ39}ZE
catch(IOException e) /*mI<[xb
{ /h3RmUy
e.printStackTrace (); h S&R(m
} +cN8Y}V
.aQ \jA
1mG-}
return n; 2P0*NQ
} s;Q!X ?Q
@\#td5'
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} Gyc]?m
(f"4,b^]
yY q,*<G
/* [{,1=AB
**SiteInfoBean.java `[ir}+S
*/ CLRdm^B
package NetFox; $ddCTS^
q(84+{>B
Y$@?.)tY
public class SiteInfoBean { Lp9E:D->
oCz/HQoBk
<RL]
private String sSiteURL; //Site's URL (9dl(QSd
private String sFilePath; //Saved File's Path DB,J3bm
private String sFileName; //Saved File's Name zTU0HR3A
private int nSplitter; //Count of Splited Downloading File Y76gJ[yjn
H4+i.*T#
ep{FpB
public SiteInfoBean() ]h5tgi?_l
{//nSplitter的缺省值为5 eJ-nKkg~a
//default value of nSplitter is 5 C,4e"yynb
this("","","",5); fz "Y CHe
} 61U09s%\0
.Z *'d
N;`n@9BF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S?2>Er
{ =T7.~W
sSiteURL= sURL; Y.p;1"
sFilePath = sPath; oEpFuWp%A
sFileName = sName; VI*$em O0
this.nSplitter = nSpiltter; GZIa4A
}O p; g^W
u>vL/nI
} (#c:b
Xsa].
3!_XEN[
public String getSSiteURL() & 1f+,
{ jnwu9PQ
return sSiteURL; 1?l1:}^L
} u=e{]Ax#}
N8df8=.kw
$[ *w"iQ
public void setSSiteURL(String value) ,I;>aE<#
{ ;!Fn1|)
sSiteURL = value; ,eS)e+yzc2
} k+*u/neh
x]j W<A
%8v\FS
public String getSFilePath() 1< ?4\?j
{ S3J^,*'
return sFilePath; n+M<\
} 6ik$B
, W?VhO
.T`%tJ-Em
public void setSFilePath(String value) E2-\]?\F(
{ 1_G^w qk
sFilePath = value; ))Za&S*<
} :g/tZd$G5
uPvEwq* C
{oL>1h,%3?
public String getSFileName() 1|:KQl2q
{ ;hq\
return sFileName; Q/Rqa5LI:
} {n=|Db~S
#<xm.
6aj!Q*(WT
public void setSFileName(String value) -yg7;ff
{ `WS&rmq&'
sFileName = value; "<gOzXpa
} N2o7%gJw
-Lg Ei3m
f6p/5]=J26
public int getNSplitter() m4Zk\,1m.|
{ -nwypu
return nSplitter; %"-5 <6d
} %z$#6?OK^
!()Qm,1u
5mR 1@
public void setNSplitter(int nCount) J .<F"r>
{ 1\.pMHv/
nSplitter = nCount; ?V=CB,^
} Iu6
} W%w~ah|/]
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Gq P5Kx+=
/* $:^td/p J
**Utility.java Ho]su?
*/ ;AG()NjOO:
package NetFox; 19] E 5'AI
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+w~oH=
public class Utility { Uw:"n]G]D?
d_P` qA
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public Utility() $pz/?>!
{ +cRn%ioVi
[N'h%1]\
t#yuOUg
} 3(UVg!t
V VCZ9MVJ
//线程睡眠 uw8f ~:LT
public static void sleep(int nSecond) !`r$"}g
{ )M^ gT}M
try{ ]_$[8#kg
Thread.sleep(nSecond); p]"4#q\(
} &e3.:[~_?
catch(Exception e) &nK<:^n
{ qJw_
e.printStackTrace (); y_[vr:s5pG
} ")25 qZae
} S|}L&A
AOx[
//日志 "Yy n/
public static void log(String sMsg) t`QENXA}
{ Xnh8e
System.err.println(sMsg); TsZ@
} i@'dH3-kO
S]{oPc[7
K> e7pu
public static void log(int sMsg) >R=|Wo`Ri
{ FiU#T.`9'
System.err.println(sMsg); 3gf1ownC
} |f##5fB
} FgO)DQm
A2Tw<&Tw(
,u!sjx
/* B/C,.?Or
**TestMethod.java -K$)DvV^(E
*/ wA.\i
package NetFox; :@&/kyGH
y?# Loe
dqAw5[qMJ
public class TestMethod { +/\6=).\
BerwI 7!=
l;V173W=&
public TestMethod() tMe~vq[
{ ///xx/weblogic60b2_win.exe QSj]ZA
try{ 1 {)Q[#l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %>s|j'{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p4)Q&k!
SiteFileFetch fileFetch = new SiteFileFetch(bean); wNX]7wMX
fileFetch.start(); ?%kV?eu'
} |7Kbpj
catch(Exception e){e.printStackTrace ();} S[QrS7
I2DpRMy
J8~haim
} 9>$p
-Qe Z#w|
A\;U3Zu
public static void main(String[] args) Wez5N
{ O'~+_ykTl
new TestMethod(); hzC>~Ub5
} PRT +mT
} {:W$LWET
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