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)); !'Q -yoHKD
} ?,yj")+
for(int i=0;i<nEndPos.length-1;i++) .Udj@{
{ sm$(Y.N
nEndPos = nStartPos[i+1]; $fgf Y8
} #);[mW{F
nEndPos[nEndPos.length-1] = nFileLength; &[hLzlrg
} vp(;W,ba:|
} #b7$TV
wR{'y)$
=f(cH152T
//启动子线程 V _c@b%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; W14Vm(`N
for(int i=0;i<nStartPos.length;i++) ( 9]_ HW[
{ &5L<i3BX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cv/_r#vN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b}Zd)2G
nStartPos,nEndPos,i); ".dZn6"mI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :eZh'-c?
fileSplitterFetch.start(); `CeJWL5{
} *:O.97q@h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o!~Jzd.=h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9!><<7TS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V_Wwrhua
nEndPos = " + nFileLength); #6!52
// fileSplitterFetch[nPos.length-1].start(); A_;8IlW
F_bF
apk4j\i?5
//等待子线程结束 ,<A$h3*
//int count = 0; .6OgO{P:
//是否结束while循环 !d&C>7nb
boolean breakWhile = false; ^GBe)~MT
nhN);R~o"1
X";@T.ZGut
while(!bStop) w}{5#
{ 5Q=P4w!'
write_nPos(); Pf F=m'
Utility.sleep(500); ]x&u`$F
breakWhile = true; z5bo_Eq
s :`8ZBz~
Cg616hyut
for(int i=0;i<nStartPos.length;i++) 3v")J*t
{ }$\M{#C~
if(!fileSplitterFetch.bDownOver) "z<azs
{ Od?qz1
breakWhile = false; -LM;}<
break; hva2o`
} <A9y9|>o
} Jdy=_88MD
if(breakWhile) %okzOKKX
break; X{kpSA~
KFZm`,+69
QKE9R-KTE
//count++; +-B^Z On
//if(count>4) 6:% L![FX
// siteStop(); JH7Ad (:
} Ez{MU@Fk
<[GYLN[0Q
L>Mpi$L
System.err.println("文件下载结束！"); C%~a`e|/Y
} wZh:F !
catch(Exception e){e.printStackTrace ();} Bb{!Yh].:A
} >*$;
GjB]KA^
Kq.:G%
//获得文件长度 -VZRujl
public long getFileSize() .q][? mW3
{ >\w&6i~
int nFileLength = -1; 8_K60eXz
try{ +wW@'X
URL url = new URL(siteInfoBean.getSSiteURL()); U}$DhA"r"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4'p=p#o
httpConnection.setRequestProperty("User-Agent","NetFox"); )fdE6
VGqa)ri"
irk*~k ?
int responseCode=httpConnection.getResponseCode(); p*5\+WO>!(
if(responseCode>=400) C[WCg9Av
{ _j>;ipTb+
processErrorCode(responseCode); +}Av-47`h
return -2; //-2 represent access is error aiCn"j
} 1qi@uYDug
pb0E@C/R
]xd^%q*
String sHeader; -A-tuyIsh"
79=45'8
Z2"?&pKV
for(int i=1;;i++) hO[3Z^X
{ 6x=YQwn~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a,7&"
//Utility.log(in.readLine()); dd|W@Xp -
sHeader=httpConnection.getHeaderFieldKey(i); Iak0 [6Ey
if(sHeader!=null) x7T+>
{ 8e0."o.6
if(sHeader.equals("Content-Length")) s/Xb^XjS1
{ htP|3B
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1nPZ<^A&@
break; w{ `|N$
} ^nVl (^{
} {0!#>["<
else 3?&h^UX
break; fE,9zUo
} *5,c Rz
} CVXytS?@x
catch(IOException e){e.printStackTrace ();} #=}$OFg
catch(Exception e){e.printStackTrace ();} R.s|j=
`P@- %T
]IJv-(
Utility.log(nFileLength); c<+;4z
%f8Qa"j
@U -$dw'4
return nFileLength; 8RwX=
} t5 a7DD
BKU'`5`
~YCuO0t
//保存下载信息（文件指针位置） fRTo.u
private void write_nPos() Mp\<cE
{ 6aOp[-Le
try{ )gR=<oa
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1px\K8
output.writeInt(nStartPos.length); nws"RcP+Z
for(int i=0;i<nStartPos.length;i++) FbACTeB
{ A<YsfDa_d
// output.writeLong(nPos); j;K#]
output.writeLong(fileSplitterFetch.nStartPos); O7aLlZdg~
output.writeLong(fileSplitterFetch.nEndPos); u1K\@jlw
} NE|[o0On
output.close(); 0=v{RQ;W4
} *Dr5O9Y
catch(IOException e){e.printStackTrace ();} )y7_qxwbV
catch(Exception e){e.printStackTrace ();} em2_pq9q
} t^EhE
d`Q7"}uZ
6Gn4asoA
//读取保存的下载信息（文件指针位置） > 7`&0?
private void read_nPos() Gt/4F-Gn
{ #k5#j4!b
try{ lu UYo
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :6;e\UE
int nCount = input.readInt(); |sgXh9%x<
nStartPos = new long[nCount]; 5nCu~<uJ
nEndPos = new long[nCount]; ``?6=mO
for(int i=0;i<nStartPos.length;i++) 6-,m}Ce\
{ PI5j"u UO
nStartPos = input.readLong(); wz -)1!
nEndPos = input.readLong(); TF+ l5fv
} TA}UY7v
input.close(); EEf ]u7
} R_Dc)
catch(IOException e){e.printStackTrace ();} iz}sM>^
catch(Exception e){e.printStackTrace ();} Qu{cB^Ga*
} (*l2('e#@
~tm0QrJn/
`{FwTZ=6{
private void processErrorCode(int nErrorCode) INMP"1
{ +lO'wa7|3
System.err.println("Error Code : " + nErrorCode); igDyp0t
} A~-#@Z
qg,Nb
zXc}W*ymj
//停止文件下载 xQt 3[(Z
public void siteStop() a}.Y!O&
{ :\V,k~asl
bStop = true; E1>/R
for(int i=0;i<nStartPos.length;i++) m[2'd
fileSplitterFetch.splitterStop(); S-E++f9D~
6 o[/F3`
,&a`d}g&G
} oJaAM|7uv
} V"d=.Hb>
//负责部分文件的抓取 zJ& b|L
**FileSplitterFetch.java WO%h"'iJ
*/ DacJ,in_I{
package NetFox; )@:l^$x
jv}=&d
w;`m- 9<Y
import java.io.*; VfSGCe
import java.net.*; "zV']A>4H
?9U:g(v
@Y'I,e
public class FileSplitterFetch extends Thread { /BHepD}
Di??Q_$ak
/! ^P)yU,
String sURL; //File URL ~mILA->F
long nStartPos; //File Snippet Start Position _C+DBA
long nEndPos; //File Snippet End Position MguL$W&l
int nThreadID; //Thread's ID aMCO"66b
boolean bDownOver = false; //Downing is over 8l xY]UT
boolean bStop = false; //Stop identical T+TF-] J
FileAccessI fileAccessI = null; //File Access interface ! sYf<
#w~0uCzQ@
B7"Fp
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S=R3"~p
{ lpEDPvD_Vm
this.sURL = sURL; {Jx7_T&
this.nStartPos = nStart; 8&a_A:h
this.nEndPos = nEnd; ,hE/II`-d'
nThreadID = id; %RFYm
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ch,|1}bi
} R+. Nn
}V^e7d
-Z?Ck!00
public void run() |>sv8/!
{ ?6:cNdN
while(nStartPos < nEndPos && !bStop) Fd!iQ
{ ],?pe
IrO+5w
M]ap:
try{ 9.Ap~Ay.
URL url = new URL(sURL); Kx]> fHK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A +!sD5d
httpConnection.setRequestProperty("User-Agent","NetFox"); w#{l4{X|
String sProperty = "bytes="+nStartPos+"-"; }GRMZh_8
httpConnection.setRequestProperty("RANGE",sProperty); h;n\*[fDc
Utility.log(sProperty); jyjQzt >\
^('cbl
?Leyz
InputStream input = httpConnection.getInputStream(); ?Y!U*& 7
//logResponseHead(httpConnection); U?6yke
^uBwj}6
!1-&Y'+
byte[] b = new byte[1024]; V [4n'LcE
int nRead; DNho%Xk
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9}n,@@
{ h3t$>vs2F"
nStartPos += fileAccessI.write(b,0,nRead); [`bZ5*&
//if(nThreadID == 1) *SGlqR['\e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D{svR-~T
} eYDgEM
00,9azs
5&|5 a} 8
Utility.log("Thread " + nThreadID + " is over!"); pDhY%w#
bDownOver = true; lu3.KOD/
//nPos = fileAccessI.write (b,0,nRead); V* Qe5j9
} $F1_^A[
catch(Exception e){e.printStackTrace ();} 3B"7VBK{
} As}eUm)B5c
} u[mY!(>nQ
Gy^FrF
g =x"cs/[
//打印回应的头信息 %LcH>sV
public void logResponseHead(HttpURLConnection con) d qpgf@
{ =jG?v'X
for(int i=1;;i++) G:hU{S7
{ a],h<wGEx
String header=con.getHeaderFieldKey(i); d"!yD/RD
if(header!=null) l qXc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ge~,[If+
Utility.log(header+" : "+con.getHeaderField(header)); |Pf(J;'[
else D@5s8xv
break; M4H"].Zm
} i?W]*V~ply
} .S6ji~;r
CjmV+%b4
8qmknJC
public void splitterStop() (7ijt
{ mLULd}g/o
bStop = true; <hMtE/05B
} 1 Xa+%n9
wVQdUtmk
xi.IRAZX
} a G@nErdW
W7W3DBKtSm
5R"2Wd
/* +0U#.|?
**FileAccess.java z[Z2H5[
*//文件访问(定位，写) #hZQ>zcF
package NetFox; 4D GY6PS
import java.io.*; Y@ObwKcG
Kc-4W6?$
1h{>[ 'L
public class FileAccessI implements Serializable{ \"J?@
(`F|nG=X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 EM=xd~H
RandomAccessFile oSavedFile; UIz:=DJ
long nPos; >6k}HrS1V
[Ek42%
hRRkFz/0&
public FileAccessI() throws IOException *3P3M}3~\
{ HIsB|
this("",0); @kz!{g]Sn
} \w3%[+c
0K/G&c?;=
RP(a,D|
public FileAccessI(String sName,long nPos) throws IOException KS?mw`Nr
{ Y>G*'[U
oSavedFile = new RandomAccessFile(sName,"rw"); / =-6:L
this.nPos = nPos; V0s,f.a
oSavedFile.seek(nPos); 8s~\iuk
} Q%I#{+OT
hR!}u}ECd
\hrrPPD1z
public synchronized int write(byte[] b,int nStart,int nLen) %N>\:85?
{ {v,{x1
int n = -1; })KJ60B
try{ nW~$ (Qnd
oSavedFile.write(b,nStart,nLen); di--:h/
n = nLen; ,TEuM|
} @W#fui<<}Y
catch(IOException e) LSSW.Oz2L
{ %V31B\]Nz7
e.printStackTrace (); r?>Vx-
} gm(De9u
'YBi5_
|PI)A`
return n; =l_rAj~I|
} Zd8drT'@#
-%>8.#~G
c%ZeX%p
} E(% XVr0W
AfUZO^<
qQL.c+%L
/* 5dqQws-,?1
**SiteInfoBean.java 8^8>qSD1
*/ A%h~Z a
package NetFox; ]7v81G5E
Wgav>7!9
ax4*xxU
public class SiteInfoBean { O+p]3u
MF&3e#mdB
>_-!zjO8u
private String sSiteURL; //Site's URL ``+c`F?5
private String sFilePath; //Saved File's Path cES;bwQ
private String sFileName; //Saved File's Name $pjf#P8U
private int nSplitter; //Count of Splited Downloading File TH<fbd
d[)_sa
qC\]"Z`m
public SiteInfoBean() r@olC7&
{//nSplitter的缺省值为5 6`_!?u7
//default value of nSplitter is 5 u\M4`p!g=
this("","","",5); kNRyOUy
} 'G<}U343=8
>~h>#{&
L^3~gM"!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;0;3BH A
{ `<S/?I8
sSiteURL= sURL; ZEL/Ndk
sFilePath = sPath; SrdE>fNbs
sFileName = sName; j\!~9
this.nSplitter = nSpiltter; U&,r4>V@h>
M`)s>jp@w
m &9)'o
} \P*PjG?R
P)Z/JHB
Uc\|X;nkRk
public String getSSiteURL() '&N: S-
{ 2_Pz^L
return sSiteURL; ^a086n
} B"7$!Co
^Vl^,@
`x2fp6
public void setSSiteURL(String value) qnabwF
{ 's=Q.s
sSiteURL = value; =ZCH1J5"
} RcY6V_Qx
se~ *<5
:|?~B%-p[
public String getSFilePath() 5OPS&:
{ ?+bTPl;%'
return sFilePath; Tf9&,!>V
} JCM)N8~i
UN,<6D3\b
5JQd)[Im
public void setSFilePath(String value) %T3j8fC{s
{ hCU)W1q#
sFilePath = value; p#ZMABlE,P
} K.:6YXVs<
;[?J5X,
\7|s$ XQ\
public String getSFileName() 7'-)/Pk
{ Iu)L3_+
return sFileName; 9c"0~7v
} cFRSd }p=
~+nS)4(
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public void setSFileName(String value) V->.|[J
{ o%vIkXw
sFileName = value; N5:D8oWWXR
} nvU+XCx
Q'FX:[@x-S
o@qN#Mg?>}
public int getNSplitter() F@>w&A~K
{ =_#ye}E
return nSplitter; h-z%C6
} +}Qv6s#
E`oSi ez)
ZkJY.H-F
public void setNSplitter(int nCount) &>d:ewM\
{ $=\oJ-(!@S
nSplitter = nCount; @qg0u#k5
} ~0VwF
} I>N-95
*D,v>(
[,\'V0
/* E&RoaY0
**Utility.java [VfLv.8w
*/ *T.={>HE8
package NetFox; RM?_15m
rnzsfr-|(2
,gAr|x7_
public class Utility { jK ?
[+%p!T
a(Gk~vD;"
public Utility() ]=$-B
{ J,dG4.ht
}M"-5K}
>i><s>=I`
} "wc`fg"3
[15hci+-
//线程睡眠 &*V0(
public static void sleep(int nSecond) Sa?~t3*H
{ rwi2kk#@P
try{ '^P*F9
Thread.sleep(nSecond); R7\{w(`K
} :ofE8]
catch(Exception e) kMwIuy
{ y1@"H/nYJ
e.printStackTrace (); ~Mg8C9B?%3
} EvGUj$
} 'W<a54T?z
1CF7
//日志 44/0}v]
public static void log(String sMsg) @&am!+z
{ [T$$od[.
System.err.println(sMsg); L!G9O]WB
} ^>P@5gcoE(
3rXL0&3w%
2vk8+LA(6
public static void log(int sMsg) d'**wh,
{ h0y\,iWXb
System.err.println(sMsg); S`'uUvAA
} Ggxrj'r
} %8z+R m,Ot
37ri b
8V53+]c$Y
/* skmDsZzw
**TestMethod.java P /f ~
*/ h!JjN$
package NetFox; E|8s2t
I'6ed`|
\nWzn4f
public class TestMethod { hj#+8=
#!<+:y'S?
]0/~6f
public TestMethod() +Qb2LR
{ ///xx/weblogic60b2_win.exe ]UpHD.Of[t
try{ 4n.i<K8K[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .{Eg(1At
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }E)8soQR
SiteFileFetch fileFetch = new SiteFileFetch(bean); ' /@!"IXz
fileFetch.start(); *YEIG#`
} %]P@G^Bv
catch(Exception e){e.printStackTrace ();} h} b^o*
Jn^Wzn[q
ND99g
} Z{R=h7P
Do{*cSd
tM?I()Y&P
public static void main(String[] args) FdK R{dX}
{ wTJMq`sY_
new TestMethod(); 9g^./k\8%
} N#xM_Mpt
} w4&v( m
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