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)); NBGH_6DROw
} e\L8oOk#r
for(int i=0;i<nEndPos.length-1;i++) z Iu'[U
{ )SGq[B6@I
nEndPos = nStartPos[i+1]; }|=|s f
} rx|pOz,:
nEndPos[nEndPos.length-1] = nFileLength; 4V`G,W4^J
} G"t5nHY\.
} a:w#s}bL
&^jXEz;
%.|@]!C
//启动子线程 Km$\:Xo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _t^&Ah*
for(int i=0;i<nStartPos.length;i++) Dlvz)
{ NzvXN1_%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |+9&rAg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dy[X3jQB
nStartPos,nEndPos,i); YT,{E,U;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d2$IH#~9B
fileSplitterFetch.start(); OneY_<*a<
} Q=$2c[Uk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J|73.&B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vFmZ<C' )
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3bI9Zt#J%&
nEndPos = " + nFileLength); es7=%!0
// fileSplitterFetch[nPos.length-1].start(); &oMh]Z*:
"w<#^d_6
kAUymds;O
//等待子线程结束 ZN0P:==
//int count = 0; ~P-mC@C
//是否结束while循环 |FRg\#kf%
boolean breakWhile = false; [nq@mc~<
v]UwJz3<
(ToUgVW1N
while(!bStop) xAm6BB c
{ Ny/MJ#Lq
write_nPos(); $F.a><1rY
Utility.sleep(500); )^hbsMhO
breakWhile = true; #RLt^$!H
J{G?-+`
C0Z=~Q%
for(int i=0;i<nStartPos.length;i++) >vsqG=x
{ _+MJ%'>S
if(!fileSplitterFetch.bDownOver) GM<9p_ B
{ I>$&-i
breakWhile = false; OY({.uVdX
break; hDGF7
} E]r?{t`]
} owv[M6lbD
if(breakWhile) |R:'\+E
break; wMN]~|z>
|_U= z;Y
rytyw77t(
//count++; !;'=iNOYR
//if(count>4) d0> zS
// siteStop(); klhtKp_p
} F:DrX_O%
_)-o1`*-
FpU>^'2]
System.err.println("文件下载结束！"); d#wVLmKZ
} q@2siI~W
catch(Exception e){e.printStackTrace ();} f*8DCh!r"
} /Z4et'Lo
?aMOZn?
69.NPy@
//获得文件长度 TD_Oo-+\
public long getFileSize() <#HYqR',
{ hE-M$LmN@
int nFileLength = -1; /qw.p#
try{ bg0Wnl
URL url = new URL(siteInfoBean.getSSiteURL()); m#p'iU*va,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9gZ$
httpConnection.setRequestProperty("User-Agent","NetFox"); P!k{u^$L
|ENh)M8}r
kG*~|ma
int responseCode=httpConnection.getResponseCode(); NGWxN8P6
if(responseCode>=400) |wj?ed$ f
{ /Ci<xmP
processErrorCode(responseCode); bZV/l4TU
return -2; //-2 represent access is error #.[k=dj
} 3;Fhg!ZO
vvOV2n.WD
9nbLg5P
String sHeader; zx7{U8*`<
u#SWj,X
3+bt~J0
for(int i=1;;i++) D1;QC
{ <9 ;!3xG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {l>hMxij
//Utility.log(in.readLine()); +nGAz{&@r%
sHeader=httpConnection.getHeaderFieldKey(i); Y6d@h? ht
if(sHeader!=null) vr^qWn
{ 0ZO2#>gh$
if(sHeader.equals("Content-Length")) @=kSo -SX
{ sx<%2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %~S&AE-
break; DlNX 3
} igAtRX%Qx
} _J[P[(ab
else ;A!BVq
break; 7xa>
} Q NVa?'0"Y
} F4{IEZ
catch(IOException e){e.printStackTrace ();} >&k-'`Nw
catch(Exception e){e.printStackTrace ();} S21,VpW\
^Zp>G{QL{
POR\e|hRT]
Utility.log(nFileLength); L j$;:/G
!{41!O,K#
G*v,GR
return nFileLength; >lM l
} &jr3B;g!C
& ZB
E1f\%!2l
//保存下载信息（文件指针位置） 2GStN74Xr
private void write_nPos() ~y[7K{{ ;T
{ Mb7I[5v
try{ >-{Hyx
output = new DataOutputStream(new FileOutputStream(tmpFile)); !0E&@X:-
output.writeInt(nStartPos.length); ws^ np
for(int i=0;i<nStartPos.length;i++) 7J&4akT{9
{ SK.: Q5:
// output.writeLong(nPos); pY$Q
output.writeLong(fileSplitterFetch.nStartPos); <b<j=_3
output.writeLong(fileSplitterFetch.nEndPos); GowH]MO
} jlg(drTo
output.close(); >&#)Tqt!?
} 5rUdv}.
catch(IOException e){e.printStackTrace ();} @ur+;IK$
catch(Exception e){e.printStackTrace ();} T9q-,w/j;
} aFIw=c(nP
W`*r>`krVJ
/5AJ.r
//读取保存的下载信息（文件指针位置） FU<Jp3<%
private void read_nPos() XBw)H
{ S#[j )U-
try{ :P=(k2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Oz#{S:24M+
int nCount = input.readInt(); w)jISu;RG
nStartPos = new long[nCount]; G<;*SYAb
nEndPos = new long[nCount]; S>; 5[l 4
for(int i=0;i<nStartPos.length;i++) 9JKEw
{ HLHz2-lI
nStartPos = input.readLong(); 7})[lL`\s
nEndPos = input.readLong(); cPc</[x[W
} ]]j;/TiG
input.close(); {2"zVt#h
} ~.lPEA %%
catch(IOException e){e.printStackTrace ();} xA[mm
catch(Exception e){e.printStackTrace ();} Q.c\/&
} ROZF)|l
w.-!UD9/.x
*G9V'9
private void processErrorCode(int nErrorCode) k+l b@!
{ 9k[9P;"F:
System.err.println("Error Code : " + nErrorCode); 8qu6.
} n@[O|?S
-;k+GrLr^
"Os_vlapHo
//停止文件下载 xFg>SJ7]
public void siteStop() wo5
{ SOvF[,+
bStop = true; `n?DU;,
for(int i=0;i<nStartPos.length;i++) c-FcEW
fileSplitterFetch.splitterStop(); t.\dpBq
i<g-+Qs
%BB%pC
} ^D-/`d
} w917N4$
//负责部分文件的抓取 j^2j&Ta
**FileSplitterFetch.java {+Cy U!O
*/ QoH6
package NetFox; @49S`
0Pi:N{x8
&~U ]~;@
import java.io.*; B@ KQ]4-
import java.net.*; ('p5:d
Tc3yS(aq
^\,E&=/}M
public class FileSplitterFetch extends Thread { WvZ8/T'x
0NX,QD
c_!cv":s
String sURL; //File URL l0i^uMS
long nStartPos; //File Snippet Start Position "i W"NFO
long nEndPos; //File Snippet End Position )B8$<sv
int nThreadID; //Thread's ID r^ ZEImjc
boolean bDownOver = false; //Downing is over D=&Me=$
boolean bStop = false; //Stop identical K8Y=S12Ti
FileAccessI fileAccessI = null; //File Access interface 4)o
$\y'IQ%
gjzuG<7m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i,9)\1R
{ 7EO_5/cY
this.sURL = sURL; PXNh&N
this.nStartPos = nStart; WVvvI9
this.nEndPos = nEnd; 6<(.4a?
nThreadID = id; fXQNHZ|4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i&GH/y
} Xh;#
zjoq6
gEE\y{y
public void run() Qv/=&_6
{ Hc(OI|z~
while(nStartPos < nEndPos && !bStop) kt$jm)UI~l
{ ZbAcO/
[Hh9a;.*}h
y9}>:pj4
try{ $l&(%\pp
URL url = new URL(sURL); a-L;*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *,WU?tl&
httpConnection.setRequestProperty("User-Agent","NetFox"); UFb)AnK
String sProperty = "bytes="+nStartPos+"-"; /FEVmH?
httpConnection.setRequestProperty("RANGE",sProperty); L8#5*8W6
Utility.log(sProperty); OX\F~+
O/(xj2~$J
vTw>JNVI
InputStream input = httpConnection.getInputStream(); GYUn6P
//logResponseHead(httpConnection); p,i[W.dy.'
'u<juFr
(;^syJrh
byte[] b = new byte[1024]; J!U}iD@occ
int nRead; Pw!MS5=r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ChXq4]
{ -Wi` G
nStartPos += fileAccessI.write(b,0,nRead); p|D/;Mk
//if(nThreadID == 1) scLll,~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BbS4m
} c.F6~IHu7
) M BQuiL
qR+!l(
Utility.log("Thread " + nThreadID + " is over!"); 54li^
bDownOver = true; Dy8r 9
//nPos = fileAccessI.write (b,0,nRead); cY.bO/&l
} agW@{c
catch(Exception e){e.printStackTrace ();} ysf~|r4s
} W'+:'_{j:
} 2Dj%,gaR
:@A9](gI
_8UDT^?8,
//打印回应的头信息 M%;hB*9
public void logResponseHead(HttpURLConnection con) L.0mk_&
{ ]G< Vg5
for(int i=1;;i++) a]tVd#
{ Px`!A EFd[
String header=con.getHeaderFieldKey(i); ':m,)G5&
if(header!=null) ly3\e_z:G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HcSXsF
Utility.log(header+" : "+con.getHeaderField(header)); Y,t={HiclX
else ,0HRAmG
break; F,)%?<!I
} nq8C'Fo!6T
} 2Gaa(rJ5o
6]%sFy2
*U=s\
public void splitterStop() ;&-k#PE]/H
{ ; _1 at
bStop = true; rK]Cr9WM
} =CVBBuVy
}"!I[Ek> y
:I^;jdL
} x-.?HS[
t$#jL5
vJOw]cwq
/* XtSkh] #z!
**FileAccess.java uurh??R
*//文件访问(定位，写) dZ0vA\z|
package NetFox; s 3f-7f<
import java.io.*; o;<Xo&
(tw)nF
@8rx`9
public class FileAccessI implements Serializable{ 0-yp,G
H{?vbqQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "v({,
RandomAccessFile oSavedFile; e5*hE
long nPos; [o+q>|q
T\j{Bi5 \J
8jo p_PG'
public FileAccessI() throws IOException 90*5 5\>{
{ `gf0l /d
this("",0); D}8[bWF
} 8MzVOF{"
)@Yf]qx+Y<
mtmjZP(w
public FileAccessI(String sName,long nPos) throws IOException Y^}Z>
{ x&Kh>PVh\
oSavedFile = new RandomAccessFile(sName,"rw"); p &"`RS#Z
this.nPos = nPos; W~9tKT4
oSavedFile.seek(nPos); qjdMqoOCjl
} (VEpVn3{
eMY<uqdw
ah0`KxO]
public synchronized int write(byte[] b,int nStart,int nLen) # ,_u_'C*!
{ ,-d0b0
int n = -1; *ipFwQ
try{ MUREiL9L|
oSavedFile.write(b,nStart,nLen); 4UvZ)^r
n = nLen; MWpQ^dL_
} 4DOH`6#an
catch(IOException e) pRIhFf
{ p=GBUII #
e.printStackTrace (); g<f <Ip=
} N&g3t%F
b Y\K
5l2 ?
return n; IIF]/Ek]
} se>8Z4
hYNY"VB
k_5L4c:"
} q?DTMKx
vZ&T}H~8
iwp{%FF
/* CpeU5 o@
**SiteInfoBean.java 4NzwE(
*/ _Wp{[TH
package NetFox; %GA"GYL9'
Xr$J9*Jk-
BJsz2t :0
public class SiteInfoBean { W;L7SF g)
C|).;V&
wq(7|!Eix
private String sSiteURL; //Site's URL (@<c6WS
private String sFilePath; //Saved File's Path ],FMwCI
private String sFileName; //Saved File's Name 9~mh@Kgv
private int nSplitter; //Count of Splited Downloading File JedmaY06=
L>9V&\
8WbgSY`
public SiteInfoBean() f'-i o<.
{//nSplitter的缺省值为5 aM2l2
//default value of nSplitter is 5 )Sg~[WxDv
this("","","",5); hjB@o#S
} dWUm\t'#
"UGY2skf;
_w/EP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4UlyxA~
{ w' OXlR
sSiteURL= sURL; I^UC&5dC
sFilePath = sPath; (-xS?8x$
sFileName = sName; NI#:|}CYS
this.nSplitter = nSpiltter; ,5kKimTt
7;sj%U^'l
bRJMYs
} 5eoska#y
/!Wu D\B
}Q?c"H!/
public String getSSiteURL() Hh-+/sO~"
{ %?uc><&?e
return sSiteURL; ;WM"cJo9
} $Ifmc`r1
cU@SIJ)
[}/LD3
public void setSSiteURL(String value) u7\J\r4,+
{ /#-C4"|
sSiteURL = value; R)z4n
} {QZUDPPR
*4xat:@{{
SHbtWq}T
public String getSFilePath() ~\.w^*$#Y
{ ^3{TZ=_;|
return sFilePath; OK6]e3UO
} ;04Ldb1{|3
L ugn3+
Rhz_t@e
public void setSFilePath(String value) W?aI|U1
{ RGg(%.
sFilePath = value; S\5bmvqP"
} B}?5]N==]
C>$E%=h+_
2H6,'JK@F
public String getSFileName() j =WST
{ qg!|l7e
return sFileName; ~j5x+yC
} #iWSDy
}L3oR
]Nl=wZ#`
public void setSFileName(String value) 2viM)+
{ mc_ch$r!
sFileName = value; 9@52Fg;mj
} *R3f{/DK
PBxCx3a{
X4t s)>"d
public int getNSplitter() .k9{Yv0
{ 7J|VD#DE$Y
return nSplitter; 0-|byAh
} \B 0ywN?
2Sp=rI
pN9A{v(
public void setNSplitter(int nCount) %8Dzo
{ a{J,~2>
nSplitter = nCount; Eam
} dBe`p5Z
} oiyzHx
Tp?y8r
s]mY*@a%
/* dd%h67J2<
**Utility.java : G`hm{
*/ DrBUe'RH:M
package NetFox; _ozg_E
~r$jza~o(
,0~9dS
public class Utility { :l&V]}:7*
^#1.l=s
?(m jx
public Utility() tBT<EV{ G
{ AfP'EP0m
MpqZH{:?G
B`o]*"xkB
} 0i|oYaC
rBTeb0i?
//线程睡眠 C2xL1`
public static void sleep(int nSecond) 4jBC9b}O
{ <~!Hx+j
try{ eKz?"g/j
Thread.sleep(nSecond); iNWo"=J
} HJ[/|NZU$
catch(Exception e) ~7t$MF.
{ ,4,V4 N
e.printStackTrace (); 0}FOV`n
} ""h)LUrl
} )a3J9a;ZS0
,H2D
//日志 f{i8w!O"~
public static void log(String sMsg) N, *m ,
{ D?,#aB"
System.err.println(sMsg); M$d%p6Cv
} G4;3cT3'
aKlUX
Cb@3M"1:
public static void log(int sMsg) 1q3( @D5~+
{ R:AA,^Z
System.err.println(sMsg); 1>Dl\czn
} 5"]~oPK
} =rQP[ICs!
-}4NT{E
pge++Di
/* { "xln/
**TestMethod.java :nS;W
*/ G,<T/f .{$
package NetFox; A'K%WW*'U
#nO|A\N
d90Z,nex
public class TestMethod { 7GSV
G #T<`>T
B_l{<
public TestMethod() m6yIR6H
{ ///xx/weblogic60b2_win.exe t"lyvI[
try{ p,<&zHb>K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `)h6j)xiQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jWO/ xX
SiteFileFetch fileFetch = new SiteFileFetch(bean); GK}'R=
fileFetch.start(); M9f?q.Bv
} !k(_PM
catch(Exception e){e.printStackTrace ();} {(#%N5%
Hb(B?!M)
^*= 85iyo
} N+)?$[
0hn-FH-XE
Q2];RS3.
public static void main(String[] args) ?Xo*1Z =
{ 70Yjv1i
new TestMethod(); bo=ZM9
} %tt%`0
} A[dvEb;r
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