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)); FHVZ/ e
} "R-1G/
for(int i=0;i<nEndPos.length-1;i++) yBKkx@o#z
{ MIPmsEdBi
nEndPos = nStartPos[i+1]; "|{O%X
} pqPhtWi%PJ
nEndPos[nEndPos.length-1] = nFileLength; =T$-idx1l
} k36%n *4
} MR$Bl"d
45l/)=@@B
cDMA#gp
//启动子线程 3R%'<MV|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (,eH*/~/
for(int i=0;i<nStartPos.length;i++) mjbr}9
{ a%>p"4WL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Uv,_VS(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D'e'xU
nStartPos,nEndPos,i); "=I ioY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lJ!+n<K+
fileSplitterFetch.start(); EJP##eGx
} olzP=08aaV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I^'kt[P'FZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'ypJGm
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SS@F:5),
nEndPos = " + nFileLength); 4CO:*qG)o
// fileSplitterFetch[nPos.length-1].start(); (9x8,f0z
CW>f;
,mH2S/<}S
//等待子线程结束 ]Lq9Ompf(t
//int count = 0; cCN[c)[c|
//是否结束while循环 L_uliBn
boolean breakWhile = false; O#Ab1FQn
\?)@ #Qs
afRUBjs
while(!bStop) .3k"1I '\
{ _@0>yMZ^
write_nPos(); Jq)!)={
Utility.sleep(500); $aTZC>R
breakWhile = true; /7X:=~m
CN0&uyu#4
Z++JmD1J
for(int i=0;i<nStartPos.length;i++) /)?]vKMiI
{ B3uv>\
if(!fileSplitterFetch.bDownOver) hRZ9[F[[
{ 5S:#I5Wa
breakWhile = false; @~Z:W<X
break; %\-u&
} DWDL|4 og
} Q}ho Y
if(breakWhile) A][\L[8X
break; jJ86Ch
!=>pI/ECQ*
31-%IkX+k
//count++; 9/R|\
//if(count>4) Qy |*[
// siteStop(); 8E{<t}
} @%@uZqQ4
)y-y-B=+T
v0`E lkaN
System.err.println("文件下载结束！"); C#X|U2$
} cMxTv4|wui
catch(Exception e){e.printStackTrace ();} OL&ku &J_
} L2Uk/E
"Q]`~u':
T:S+Pt~
//获得文件长度 3=V79&
public long getFileSize() NK'awv),pM
{ RajzH2j+>
int nFileLength = -1; +K2jYgy
try{ Fn4i[|W42
URL url = new URL(siteInfoBean.getSSiteURL()); G^J|_!.a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \"i2E!
httpConnection.setRequestProperty("User-Agent","NetFox"); RVtb0FL
O7bTu<h=
u$d T^c
int responseCode=httpConnection.getResponseCode(); "1_eZ`
if(responseCode>=400) * 3mF.^
{ )2C`;\/:
processErrorCode(responseCode); " cx\P,<
return -2; //-2 represent access is error QcG4~DEX4
} ^.y}2
lw0l86^Y
IBr?6_\%"4
String sHeader; /qA\|'~
W#E-vi+l
Hj"`z6@7
for(int i=1;;i++) PvX>+y5
{ ZFh2v]|!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _M= \s>;G
//Utility.log(in.readLine()); dX-Xzg
sHeader=httpConnection.getHeaderFieldKey(i); 82Dw,Cn
if(sHeader!=null) '+^HeM^;
{ <7cm[
if(sHeader.equals("Content-Length")) !lp*0h(7
{ U=MFNp+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N=lFf+
break; Hzh?w!Ow
} ,-#8/9ts
} !8M]n
else smW 7zGE
break; V9f$zjpw
} .4pWyqU)!
} |T0jq
catch(IOException e){e.printStackTrace ();} Q1? !,a
catch(Exception e){e.printStackTrace ();} Nw'i;}0v7r
gtWJR
X*6bsYbK-
Utility.log(nFileLength); pq$`T|6^
vK z/-9im
+gh6eY8
return nFileLength; chW 1UE
} {(#Dou
:hB/|H*=
~#+ Hhc(
//保存下载信息（文件指针位置） JSCe86a7<E
private void write_nPos() G4][`C]8c
{ 0@[]l{N
try{ #@Yw]@5M
output = new DataOutputStream(new FileOutputStream(tmpFile)); uH S)
output.writeInt(nStartPos.length); B B*]" gT
for(int i=0;i<nStartPos.length;i++) wB~Ag$~
{ Z}6
// output.writeLong(nPos); Xc-'&"
output.writeLong(fileSplitterFetch.nStartPos); =n|n%N4Y
output.writeLong(fileSplitterFetch.nEndPos); .XQ_,
} EEmYfP[3
output.close(); E4~k)4R
} fOs}5J
catch(IOException e){e.printStackTrace ();} WrBiAh,
catch(Exception e){e.printStackTrace ();} "b5:6\
} "HSAwe`5jU
A46z2
8%v1[Wi
//读取保存的下载信息（文件指针位置） dUiv+K)ccQ
private void read_nPos() GF[onfQY7
{ $ \0)~cy
try{ qg6283'?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ousvsP%'
int nCount = input.readInt(); .jW+\mIX
nStartPos = new long[nCount]; K9h{sC
nEndPos = new long[nCount]; ;(AVZxCM
for(int i=0;i<nStartPos.length;i++) wd&Tf R4!
{ 7:'7EqM
nStartPos = input.readLong(); V'y,{YpP
nEndPos = input.readLong(); $6Z@0H@X
} @*'$QD,
input.close(); ~_R8; b
} 0w[#`
catch(IOException e){e.printStackTrace ();} FYU)sQ
catch(Exception e){e.printStackTrace ();} ,tBb$T)7<
} c+P.o.k;
K1]m:Y<
Obwj=_+upd
private void processErrorCode(int nErrorCode) -)_"7}|u5
{ seO7/h_a
System.err.println("Error Code : " + nErrorCode); KLi&TmIB
} R+Q..9P
>.^/Z/[.L
I[u%kir
//停止文件下载 $2N)m:X0
public void siteStop() AB92R/
{ HAJK%zLc
bStop = true; $A"C1)d;
for(int i=0;i<nStartPos.length;i++) t/xWJW2
fileSplitterFetch.splitterStop(); ^ 'W<|
vU(2[
*V}T}nK7
} M{:}.H<a
} _)AX/%^%
//负责部分文件的抓取 ##Jg>HL'
**FileSplitterFetch.java xfYDjf :<
*/ %DH2]B? 0
package NetFox; e%_2n=p~)%
@AM;58.
; C/:$l
import java.io.*; O~Eju
import java.net.*; z2:^Qg
.URCuB\{
-'ff0l
public class FileSplitterFetch extends Thread { %dA6vHI,
aYc*v5QN3
ft$@':F
String sURL; //File URL 'a8{YT4
long nStartPos; //File Snippet Start Position );X&J:-l+
long nEndPos; //File Snippet End Position -L=aZPW`M
int nThreadID; //Thread's ID AG?cI@',
boolean bDownOver = false; //Downing is over S+aXlb
boolean bStop = false; //Stop identical "_!D b&AH
FileAccessI fileAccessI = null; //File Access interface GZ xG!r-
};{V]f 0
c8'a<<sj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l0hcNEj{W
{ w"?H4
this.sURL = sURL; <OF2\#Nh
this.nStartPos = nStart; OEMYS I%
this.nEndPos = nEnd; 5cY([4,
nThreadID = id; n."vCP}O+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @ Gxnrh6
} KY}c}*0
tCZ3n
E8$k}I
public void run() j0^%1
{ [1Cs
while(nStartPos < nEndPos && !bStop) ry^FJyjW
{ .;),e#
']]Czze
r57CyO
try{ k'H+l]=
URL url = new URL(sURL); `v;9!ReZV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,ddoII
httpConnection.setRequestProperty("User-Agent","NetFox"); zvJQ@i"Z
String sProperty = "bytes="+nStartPos+"-"; Yi?X|"\`
httpConnection.setRequestProperty("RANGE",sProperty); %ae|4u#b
Utility.log(sProperty); ddR*&.Y!a
mar6/*`I#+
=v-qao7xCV
InputStream input = httpConnection.getInputStream(); OFcLh
//logResponseHead(httpConnection); nd~cpHQR^
zn!H&!8&
LmCr[9/
byte[] b = new byte[1024]; =EE>QM
int nRead; =rH' \7T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dXwfOC\\
{ H[H+s!)"
nStartPos += fileAccessI.write(b,0,nRead); gzV&S5A{_
//if(nThreadID == 1) xLZJ[:gr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kBF.TGT[l
} +OEheG8
'MF|(`
;!RS q'L1
Utility.log("Thread " + nThreadID + " is over!"); V]4g- CS[
bDownOver = true; yiourR)H<
//nPos = fileAccessI.write (b,0,nRead); uP;qs8
} suo;+T=`I
catch(Exception e){e.printStackTrace ();} rf}@16O$'
} WDrC
} QkY]z~P4
:9nqQJ+~
i-kj6N5
//打印回应的头信息 ^a,Oi%
public void logResponseHead(HttpURLConnection con) _f^JXd,7v
{ }vx+/J
for(int i=1;;i++) fLGZ@-qA0
{ pv LA:LW2
String header=con.getHeaderFieldKey(i); $-x@P9im
if(header!=null) }MW7,F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2=?:(e9
Utility.log(header+" : "+con.getHeaderField(header)); fv;3cxQp
else i\h"N K
break; HV*Dl$
} >VnBWa<j3
} *!mT#Vm^
)iKV"jsC
[.ya&E)x
public void splitterStop() Vn7FbaO^
{ q:iB}ch5R
bStop = true; CO%o.j=1
} M/Twtq-`H
seNJ6p=`
pUp&eH
} hN#A3FFo L
%$'YP
V?yTJJ21X
/* PN(P$6
**FileAccess.java _klT
*//文件访问(定位，写) v@qU<\Y>
package NetFox; ~4T:v_Q7g
import java.io.*; [5"F=tT7WP
w6Owfq'v
c] '-:=
public class FileAccessI implements Serializable{ 2:8p>^g=
<SPT2NyX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jV)4+D
RandomAccessFile oSavedFile; MS>QU@z7c
long nPos; l-mt{2
oh?@[U
[yyL2=7
public FileAccessI() throws IOException ]cKxYX)J
{ 3D2\#6yo
this("",0); ^!FLi7X
} 8AGP*"gI
9w"kxAN
+[lv `tr
public FileAccessI(String sName,long nPos) throws IOException R=co2 5
{ n2p(@
oSavedFile = new RandomAccessFile(sName,"rw"); t ;-U
this.nPos = nPos; # fe%E.
oSavedFile.seek(nPos); >Ohh)$
} x("V+y*
23iMG]J&
Y9w^F_relL
public synchronized int write(byte[] b,int nStart,int nLen) nf2[hx@=U
{ @5,Xr`]
int n = -1; kc:>[{9
try{ `0z8J*T]
oSavedFile.write(b,nStart,nLen); IE0hC\C}
n = nLen; QIWfGVc-
} `^G?+p2E
catch(IOException e) _@/nc:)H
{ N,0&xg3
e.printStackTrace (); !\hUjM+(}
} cq0#~20
1${rQ9FIF
MRb6O!$`C
return n; Fu$JI8
} D>`lN
~6!TMVr
H\^zp5/
} ;%YAiW8{Xk
*f*o ,~8V1
Ni Y.OwKr
/* C4.g}q
**SiteInfoBean.java s+@`Z*B5
*/ rsPo~nA
package NetFox; ^)i1b:4
C#tY};t
x:0nK,
public class SiteInfoBean { "b `R_gG9
Ra-%,cS
Og E<bw
private String sSiteURL; //Site's URL vNIQ1x5Za
private String sFilePath; //Saved File's Path YCI-p p
private String sFileName; //Saved File's Name Pgo^$xn'6
private int nSplitter; //Count of Splited Downloading File V 3yt{3Or
FI=]K8
(;T g1$
public SiteInfoBean() o"Mhwh
{//nSplitter的缺省值为5 }\oy%]_mY
//default value of nSplitter is 5 UtzM+7r@
this("","","",5); Z%9_vpWc
} ]R%+
Re]7G.y
y=qiGi[Nc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -d8U Hc
{ 2r*Yd(e
sSiteURL= sURL; fb;y*-?#
sFilePath = sPath; K)_DaTmi)
sFileName = sName; j3_vh<U\
this.nSplitter = nSpiltter; /{sFrEMP\
n*nsFvt%o
WgayH
} xwe^_7
01&J7A2
)2dTgvy
public String getSSiteURL() #57D10j
{ 0$1-5XY9
return sSiteURL; *)0-N!N#)
} |x/00XhS
kr{eC/Q"
$*N)\>~X
public void setSSiteURL(String value) ;Q8LA",5d
{ qpZR-O
sSiteURL = value; ,#blY~h8^
} Api<q2@R
's7 (^1hH
@yxF/eeEy+
public String getSFilePath() F?*ko,
{ yf@DaIG
return sFilePath; )D>= \Me
} 5 4vDP9
]s<}'&
%wk3&EC.
public void setSFilePath(String value) 5A`T}~"X
{ h&O8e;S#
sFilePath = value; YfZ96C[a
} EI!e0V1!
dWDM{t\}\
wD|I^y;
public String getSFileName() rQM$lJ[x
{ *Iir/6myM
return sFileName; `S+B-I0
} m%[`NP (
o|O|e9m(
'BmLR{[2L
public void setSFileName(String value) .^aqzA=]
{ "o6a{KY(
sFileName = value; jt,dr3|/n
} nr>Os@\BU
3,[#%}1(S
A[6D40o
public int getNSplitter() Y24H` s1u/
{ f'28s*n
return nSplitter; @24)*d^1
} =}^J6+TVL
RI</T3%~
^j>w<ljzz
public void setNSplitter(int nCount) c3]X#Qa#m$
{ D/x!`&.sN
nSplitter = nCount; M#a1ev
} N,F$^ q6
} d@aPhzLu
.|Y&,?k|Y
7w?V0pLwn8
/* unZYFA}(
**Utility.java A1uo@W
*/ `Eq~W@';Q0
package NetFox; MeMSF8zSQ
NPY\ >pf
/CfgxPo
public class Utility { &w"1VOV<
lwj,8
~P;KO40K
public Utility() P<s0f:".
{ 6X`i*T$.
I`-N]sf^
@&fAR2
} ZA{T0:
h =E)5&Z
//线程睡眠 rD":Gac
public static void sleep(int nSecond) }{#ty uzAo
{ jSc!"Trl]
try{ bxR6@
Thread.sleep(nSecond); BfOQ/k))
} PTZ/jg@71
catch(Exception e) Z?"f#
{ 'PK;Fg\
e.printStackTrace (); |'ML )`c[
} BK;Gh0mp
} {.mPe|
Oll,;{<O
//日志 Pua|Z x
public static void log(String sMsg) f:hsE
{ wR]jJbF
System.err.println(sMsg); ?CU6RC n
} Ww)p&don
OJ!=xTU%h
#|R#/Yc@Bv
public static void log(int sMsg) HmQ.'
{ *JT,]7>
System.err.println(sMsg); X" m0||
} |0N6]%r
} {@YY8SKb9
su\iUi
pEp`Z,p
/* P#o"T4 >
**TestMethod.java F)n^pT
*/ nkTpUbS'f?
package NetFox; AS? ESDC
(2uF<$7(
[Rxbb+,U
public class TestMethod { d.3cd40Q
#ExNiFZ
hteAuz4H
public TestMethod() <reALC
{ ///xx/weblogic60b2_win.exe JG/Pc1aK
try{ $~c wB
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZULnS*V;5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ic;M=dsh:
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7U647G(Sg
fileFetch.start(); ,7h0y
} R(AS$<p{!>
catch(Exception e){e.printStackTrace ();} J5Ovj,[EZ
+oevNM
s~'"&0Gz
} q5xF~SQGw2
h<<uef9
CC B'
public static void main(String[] args) Ms 3Sri
{ \"pp-str
new TestMethod(); o]M1$)>b+
} r#'ug^^k$X
} XY^]nm-{I
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