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)); J}+6UlD
} 'BPp ]R#{
for(int i=0;i<nEndPos.length-1;i++) 7MHKeLq
{ V=V:SlS9|
nEndPos = nStartPos[i+1]; M&Uj^K1
} 3]UUG
nEndPos[nEndPos.length-1] = nFileLength; j|%HIF25
} U,q\emR
} be-~\@
jvFTR'R)=
R_7 d@FQ1
//启动子线程 \":m!K;Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &8_gRP
for(int i=0;i<nStartPos.length;i++) <U >>ZSi
{ 1ilBz9x*!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;Q[mL(1:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wK-3+&,9
nStartPos,nEndPos,i); z3M6V}s4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w1"nffhO
fileSplitterFetch.start(); %r6y ;vAf
} xA$nsZ]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *2Ht&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rZ^v?4Z\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I_rO!
nEndPos = " + nFileLength); YY!6/5*/]
// fileSplitterFetch[nPos.length-1].start(); \y)
S9`flo
uVDa^+=
//等待子线程结束 Pgus42f%
//int count = 0; O1*NzY0Y%-
//是否结束while循环 Kt|1&Gk
boolean breakWhile = false; /_Z652@
K7Wk6Aw
G\r?f&
while(!bStop) iN0nw]_*
{ "D=P8X&vs
write_nPos(); -'BA{#e}L
Utility.sleep(500); 69NQ]{1
breakWhile = true; yz*6W zD
'07P&g-
1u(.T0j7f
for(int i=0;i<nStartPos.length;i++) ixQJ[fH10
{ XWs"jt
if(!fileSplitterFetch.bDownOver) pV,P|>YTf
{ GJp85B!PlO
breakWhile = false; (tGY%oT"
break; 16i"Yg!*
} J8)#PY[i4
} H;fxxu`cS
if(breakWhile) z0*_^MH
break; }HYjA4o\A
wz.6du6-
eT8}
//count++; H4!+q:<
//if(count>4) /E5 5Pec
// siteStop(); ^:* 1d \
} Z(_ZAB%+D
*`Yv.=cd
;cz|ss=
System.err.println("文件下载结束！"); Ox'/`Mppw
} ['*8IWg
catch(Exception e){e.printStackTrace ();} w{90`
} z7Eg5rm|QZ
g HbxgeL
6]pX>Xho
//获得文件长度 -7&Gi +]
public long getFileSize() D<X.\})Md
{ R% ,<\d7
int nFileLength = -1; ZwerDkd
try{ NDAw{[.%
URL url = new URL(siteInfoBean.getSSiteURL()); BC;:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,b;{emX h
httpConnection.setRequestProperty("User-Agent","NetFox"); { e5/+W
tP%{P"g3^
GMZv RAui
int responseCode=httpConnection.getResponseCode(); j"@93D~
if(responseCode>=400) gzD@cx?V
{ 0Ir<y
processErrorCode(responseCode); Gkxj?)`
return -2; //-2 represent access is error 2'<[7!
} dVo.Czyd
R &4Z*?S
+@K09ge
String sHeader; A4?+T+#d
lP!;3iJ B
WJ9cZL
for(int i=1;;i++) ^3FE\V/=
{ {; >Q.OX@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); P7f,OY<@%o
//Utility.log(in.readLine()); f5==";eP
sHeader=httpConnection.getHeaderFieldKey(i); (V%`k'N7f
if(sHeader!=null) FSbHn{@
{ NwR}yb6
if(sHeader.equals("Content-Length")) Z@%HvB7
{ ;kJA'|GX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i^!ez5z
break; b(I2m
} PeE/iZ.
} .*JA!B
else F5qFYL;
break; 'vaLUy9]
} _:B1_rz7,
} RTu4@7XP
catch(IOException e){e.printStackTrace ();} Wt9Q;hK
catch(Exception e){e.printStackTrace ();} T}=>C+3r
awUx=%ERtA
=}:)y0L
Utility.log(nFileLength); BMIyskl=i
e<#DdpX!H~
I;?X f
return nFileLength; y{a$y}7#X
} /Y2/!mU</
*I0-O*Xr
rUjdq/I:Z
//保存下载信息（文件指针位置） oejfU;+$
private void write_nPos() M}wXJ8aF?
{ 5 VA(tzmCt
try{ FHPXu59u
output = new DataOutputStream(new FileOutputStream(tmpFile)); !HJ$UG/\
output.writeInt(nStartPos.length); )I-fU4?
for(int i=0;i<nStartPos.length;i++) 7 #=}:3c
{ A=-F,=k(!/
// output.writeLong(nPos); gxGrspqg
output.writeLong(fileSplitterFetch.nStartPos); kzS=g|_
output.writeLong(fileSplitterFetch.nEndPos); ^v@4|E$
} F("#^$
output.close(); [|3>MZ2/
} 56Z\-=KAU
catch(IOException e){e.printStackTrace ();} a3>zoN
catch(Exception e){e.printStackTrace ();} GBC*>Y
} N=)z
Q9`QL3LQD
a%Jx `hx
//读取保存的下载信息（文件指针位置） 5Y3i|cj
private void read_nPos() -sMytHH.
{ tB'V
try{ f0LP?]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y9|K|xO[
int nCount = input.readInt(); <d7V<&@o=
nStartPos = new long[nCount]; 7.+#zyF
nEndPos = new long[nCount]; 9=/N|m8.
for(int i=0;i<nStartPos.length;i++) Bz`yfl2
{ kV Rn`n0
nStartPos = input.readLong(); /+3a n9h
nEndPos = input.readLong(); N6[i{;K@N{
} Gj /3kS~@
input.close(); jUqy8q&
} ?QDWuPhN
catch(IOException e){e.printStackTrace ();} M'1!<a-Mp
catch(Exception e){e.printStackTrace ();} j,2l8?
} =N|kn<h4
^SfS~GQ
+tN&a
private void processErrorCode(int nErrorCode) -6Mm#sX
{ O;]?gj 1@
System.err.println("Error Code : " + nErrorCode); 2~;&g?T6
} J:F^ #gW
7CB#YP?E
8S;CFyT\n
//停止文件下载 [W,-1.$!dM
public void siteStop() ;#G%U!p
{ /LQ:Sv7
bStop = true; mi2o1"Jd$`
for(int i=0;i<nStartPos.length;i++) Ld|V^9h1;
fileSplitterFetch.splitterStop(); #rYENR[
YTU.$t;Ez
`$z)$VuP
} O hR1Jaed
} !|m9|
//负责部分文件的抓取 _hCJ|Rrln
**FileSplitterFetch.java (5uJZ!m
*/ xnq><4
package NetFox; Pcu|k/tk
Nl8 gK{
twk&-:'
import java.io.*; M}.b" ljZ
import java.net.*; <kD#SV%"
-0,4egj3
M'1HA
public class FileSplitterFetch extends Thread { D(r:}pyU
-'C!"\%
!g0cC.'
String sURL; //File URL mT_GrIl[
long nStartPos; //File Snippet Start Position +CTmcbyOi
long nEndPos; //File Snippet End Position +|C[-W7Sw
int nThreadID; //Thread's ID ~r`Wr`]_z
boolean bDownOver = false; //Downing is over < `Z%O<X
boolean bStop = false; //Stop identical 3DoRE2}
FileAccessI fileAccessI = null; //File Access interface "jZm0U$,*
Z%v6xP.
D&[Z;,CHMA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B2hfD-h,>
{ P&t;WPZ
this.sURL = sURL; DcFCKji
this.nStartPos = nStart; R^Bk]
this.nEndPos = nEnd; } 21j
nThreadID = id; .u< U:*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '>^Xqn
} "r-l8r,
|@`"F5@,
*:arva5
public void run() Sa}D.SBg
{ bc}dYK3$q
while(nStartPos < nEndPos && !bStop) @ u1Q-:
{ 56s*A*z$ ;
-fux2?8M
dokuyiN\
try{ Uh+jt,RB`
URL url = new URL(sURL); dp^N_9$cdO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v"k4ATWP
httpConnection.setRequestProperty("User-Agent","NetFox"); AA7#c7
String sProperty = "bytes="+nStartPos+"-"; aii'}c
httpConnection.setRequestProperty("RANGE",sProperty); BQ#jwu0e
Utility.log(sProperty); <"I?jgo
VC=6uB
`$9L^Yg,4
InputStream input = httpConnection.getInputStream(); 31 ]7z
//logResponseHead(httpConnection); 4Vx+[8W
#,P(isEZ"
W#45a.v
byte[] b = new byte[1024]; U,3d) ]Zy&
int nRead; *tAqt2{48
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5<r)+?!n
{ _5h0@^m7y
nStartPos += fileAccessI.write(b,0,nRead); )_O.{$ to
//if(nThreadID == 1) fm6]CU1^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gDhl-
} 3*\8p6G
d H_2o
u<q)SQ1
Utility.log("Thread " + nThreadID + " is over!"); nCB[4
bDownOver = true; #wD7 \X-f
//nPos = fileAccessI.write (b,0,nRead); P6E1^$e
} D'?]yyrf
catch(Exception e){e.printStackTrace ();} eH `t \n
} ;q&Z9lm
} sKCGuw(mh
9rWLE6`
+cw{aI`a8
//打印回应的头信息 d'q;+jnP
public void logResponseHead(HttpURLConnection con) 2q|_Dma
{ (>r|j4$
for(int i=1;;i++) vF+YgQ1H
{ m^c%]5$
String header=con.getHeaderFieldKey(i); gx#J%k,f
if(header!=null) =*[, *A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9OhR41B
Utility.log(header+" : "+con.getHeaderField(header)); ,iohfZz
else _dY:)%[]
break; &?v#| qIh
} `lvh\[3^
} s/\XH&KR3V
*+&z|Pwv[^
_i.({s&_9
public void splitterStop() O<Jwaap
{ 4g S[D
bStop = true; a'm!M:w
} Age-AJ
- =yTAx
DwTi_8m;
} \v.HG] /u
_82<|NN:
D@2Ya/c
/* ^CO#QnB @
**FileAccess.java ?TRW"%
*//文件访问(定位，写) mMga"I9
package NetFox; MyK^i2eD
import java.io.*; -Zttj/K
G|<]Ma9x
W6hNJb
public class FileAccessI implements Serializable{ 'wegipK~R
QZqpF9Eu
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZyZl\\8U
RandomAccessFile oSavedFile; KhLg*EL
long nPos; Mi_[9ku>%
X"laZd947>
<r@bNx@T
public FileAccessI() throws IOException ]cS&8{ ^2
{ IQo]9Lx
this("",0); s_x=^S3~LO
} Cb+P7[X-
`6dy U_f
#!(Zn:[
public FileAccessI(String sName,long nPos) throws IOException Y#GT*V
{ [>Ikitow
oSavedFile = new RandomAccessFile(sName,"rw"); axHxqhO7zp
this.nPos = nPos; 7 _X&5ni
oSavedFile.seek(nPos); 3AX?B~s
} Y=PzN3
p!. /
ftDVxKDE?S
public synchronized int write(byte[] b,int nStart,int nLen) 2pVVoZV.<
{ :zRB)hd
int n = -1; K'>P!R:El
try{ PEMxoe<+
oSavedFile.write(b,nStart,nLen); +#&el//
n = nLen; 0V{>)w!Fo
} J(H??9(s
catch(IOException e) Ir'DA_..
{ (or =f`
e.printStackTrace (); ?z*W8b]'
} ^!zJf7(+<>
7Y|Wy Oq
}xpe
return n; nS?S6G5h
} UHTb61Gs
C?_t8G./_
VQZT.^
} PW(_yB;
<v1_F;{n
BV_a-\Sa=
/* Th I
**SiteInfoBean.java 6 d{D3e[p^
*/ }WBm%f
package NetFox; K6PC&+x
'Q^G6'(SaK
dja9XWOg
public class SiteInfoBean { ?w|\7T.?
see'!CjVo2
4cv|ok8P
private String sSiteURL; //Site's URL &**.naSo
private String sFilePath; //Saved File's Path K~9 jin
private String sFileName; //Saved File's Name ]VO,} `
private int nSplitter; //Count of Splited Downloading File :Kt mSY
*o2_EqXL*
Hf`&&
public SiteInfoBean() k_.j%
{//nSplitter的缺省值为5 tL|L"t_5x
//default value of nSplitter is 5 p]J]<QaZD
this("","","",5); Cys/1DkE
} u8$~N$L
0Zp<=\!;
.5$V7t.t$\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;9- 4J
{ pB{ f-M:D
sSiteURL= sURL; o 2$<>1^
sFilePath = sPath; ~T{d9yNW1
sFileName = sName; UVvt&=+4
this.nSplitter = nSpiltter; ~"hAb2
hPX2 Bp
))we\I__8
} `04Y ;@w
$4fjSSB~
$;g%S0:3)
public String getSSiteURL() q0xE&[C[M
{ Luu-c<*M
return sSiteURL; tL 9e~>,`
} 55)ep
xDAA`G
{U2|):
public void setSSiteURL(String value) EJ[iOYx
{ :EmMia-)J
sSiteURL = value; Ky{I&}+R|
} :O_<K&
Yru1@/;
#0$eTdx#
public String getSFilePath() /ux#U]x
{ A&@jA5Jb
return sFilePath; 8Gzs
} =z7Ay
n ;$}pg~
pRyS8'
public void setSFilePath(String value) #v]aT ]}
{ Ts?>"@
sFilePath = value; 5w-G]b
} KfI$'F #"/
3hpz.ISk
Et[QcB3
public String getSFileName() hgMnO J
{ .<|4PG
return sFileName; Y$DgL h
} 7H@Cy}a
zz''FmedF
-V)5Tr=
public void setSFileName(String value) ?f%DVK d
{ (]# JpQ
sFileName = value; "q#kh,-C
} 9\;/-0P
Y3F.hk}O
mfi'>o#
public int getNSplitter() ,t,65@3+b
{ K,T]Fuy
return nSplitter; X+G*Q}5
} nCmrt*&}
d~oWu [F*
Ns] 9-D
public void setNSplitter(int nCount) 3t}o0Ai9
{ FWx*&y~$
nSplitter = nCount; MjeI?k}LJ
} #esu@kMU`
} rzY@H }u
za 4B+&JJ
7QRvl6cv
/* 4Fht(B|
**Utility.java !wufoK
*/ /[|md0,
package NetFox; ;$&5I9N
2SCf]&
a!]QD`
public class Utility { '/)_{Ly
+,w|&y
Hr.JZ>~<
public Utility() eEb1R}@
{ .Af)y_
YSUH*i/%
pzp"NKxi
} Zvw3C%In
9MlfZsby
//线程睡眠 }qX&*DU_@
public static void sleep(int nSecond) 74N\G1
{ Bwvc@(3v
try{ [Z&s0f1Qb
Thread.sleep(nSecond); |gxB; GG
} kj"_Y"q=
catch(Exception e) WX$^[^=HC
{ rMFf8D(Y
e.printStackTrace (); (N>ew)Ke
} CX2q7azG
} a[9OtZX<
uS10P7N}
//日志 9>Z#o<*_/
public static void log(String sMsg) ])";Z
{ &wC.?w$
System.err.println(sMsg); !6`nN1A
} "4-Nnm
l.'E\3Bo
#NxvLW/
public static void log(int sMsg) hA19:H=7R0
{ m!>'}z
System.err.println(sMsg); bWzc=03
} yxq!.72
} h |
R$3+ 01j|
d-2I_ )9
/* qMj e,Y
**TestMethod.java ~./u0E
*/ I z@x^s
package NetFox; FnU;n
nff]Y$FB
dfd%A" I
public class TestMethod { B{u.Yc:
F?4'>ZW
v~=ol8J B
public TestMethod() eEFT(e5.>3
{ ///xx/weblogic60b2_win.exe eWs^[^c.<
try{ jWCC`0 T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <qiap2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #FM 'S|
SiteFileFetch fileFetch = new SiteFileFetch(bean); E8 )*HOT_T
fileFetch.start(); ^^(ZK 6d
} _!Q\Xn
catch(Exception e){e.printStackTrace ();} -$p-o Z)
a{6|[aR
4vJIO{m
} +Uk.|@b=-V
U7'oI;C$e
wBGxJ\+M
public static void main(String[] args) d'J?QH!N0
{ N%i<DsK.u6
new TestMethod(); 9~af\G
} {u][q &n
} id9T[^h
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