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)); \ Q8q9|g?]
} VE"0VB.
for(int i=0;i<nEndPos.length-1;i++) &R FM d=
{ oy2dA
nEndPos = nStartPos[i+1]; $4*E\G8
} ySK Yqt z
nEndPos[nEndPos.length-1] = nFileLength; pF*~)e
} OjlB0
} K^& ]xFW
k&_u\D"^"%
!QW 0
//启动子线程 GlgORy=>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +JAfHQm-
for(int i=0;i<nStartPos.length;i++) V<NsmC=g
{ b:5%}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [xs)u3b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), QRZTT qG
nStartPos,nEndPos,i); 9Glfi@.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ysc|kxLb
fileSplitterFetch.start(); '"fU2M<.
} nP{sCH 1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z=Y_;dS9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q,,>:]f#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $s(4?^GP
nEndPos = " + nFileLength); t"bPKFRy9E
// fileSplitterFetch[nPos.length-1].start(); b}*@=X=4o
))69a
@1SKgbt>
//等待子线程结束 031.u<_
//int count = 0; I%Po/+|+
//是否结束while循环 >-|90CSdSJ
boolean breakWhile = false; < J<;?%]
0m YZ7S5g
o`T<}z26
while(!bStop) +yP[(b/
{ 8&A|)ur4
write_nPos(); s8yTK2v2\
Utility.sleep(500); ;'Vipj
breakWhile = true; CMxjX
qfP"UAc{/
.";tnC!e
for(int i=0;i<nStartPos.length;i++) E ^SM`
{ xX&>5 "
if(!fileSplitterFetch.bDownOver) ,ORG"]_F
{ zr;Y1Xt4
breakWhile = false; rb}wv16?
break; <j1d~XU}
} l;{N/cS
} NtA|#"^
if(breakWhile) ZG\ I1
break; z Jo#3
<E7Vbb9*
j zmSFKg*
//count++; C`th^dqBV
//if(count>4) B:A1W{l
// siteStop(); k.=S+#"}
} (|a$N.e&K
x+*L5$;h
Xv7U<q
System.err.println("文件下载结束！"); Puth8$
} gcW{]0%L^
catch(Exception e){e.printStackTrace ();} .t^UK#@#4
} c]aK N
;/)Mcx]n
d0}%%T
//获得文件长度 DvRA2(M
public long getFileSize() RqN_vk\
{ |p8"9jN@}c
int nFileLength = -1; X~)V)'R
try{ rMXOwkE
URL url = new URL(siteInfoBean.getSSiteURL()); THbtu*El
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 32bkouq
httpConnection.setRequestProperty("User-Agent","NetFox"); 2NArE@
:9x084ESR)
b!^M}s6
int responseCode=httpConnection.getResponseCode(); RZ<+AX9R
if(responseCode>=400) ;*)fO?TG)
{ e0|_Z])D
processErrorCode(responseCode); e1 {t0f
return -2; //-2 represent access is error B~_,>WG
} A}#]g>L
|?fW!y
An8%7xa7
String sHeader; =ve*g&
\\2k}TsB
{sna)v$;
for(int i=1;;i++) ,2 g M-
{ ]4 K1%ZV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7i+!^Qj?y
//Utility.log(in.readLine()); M]4=(Vv+5
sHeader=httpConnection.getHeaderFieldKey(i); }4\!7]FVYX
if(sHeader!=null) \%-E"[!
{ C$'D]fX
if(sHeader.equals("Content-Length")) fZw9zqg
{ <>T&ab@dE(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =;k+g?.@I
break; Xew1LPI
} StdS$XW
} XYK1-m}2
else rt3f7 s*
break; f- k|w%R@
} |Uy e>%*}4
} 0U~;%N+lv
catch(IOException e){e.printStackTrace ();} :!+}XT7)/
catch(Exception e){e.printStackTrace ();} u^aFj%}]L
>2|[EZ
?x5wS$^q<
Utility.log(nFileLength); XoKO2<3
)DGz`->
,N@Yk.
return nFileLength; H4}%;m%
} HvqF@/xh
O:5Rp_?^
uXG`6|?
//保存下载信息（文件指针位置） ^6)GS%R
private void write_nPos() cD'HQ3+
{ jSwtf
try{ 5q(]1|Sei
output = new DataOutputStream(new FileOutputStream(tmpFile)); |P,zGy
output.writeInt(nStartPos.length); !^)wPmk
for(int i=0;i<nStartPos.length;i++) `x{.z=xC
{ Sc4obcw%
// output.writeLong(nPos); N"Qg\PS_
output.writeLong(fileSplitterFetch.nStartPos); tT@w%Sz57N
output.writeLong(fileSplitterFetch.nEndPos); Yo~LckFF
} "wnpiB}
output.close(); ;t;Y.*&=S
} ?fbgU
catch(IOException e){e.printStackTrace ();} VxkCK02k
catch(Exception e){e.printStackTrace ();} ZR;8rZ](
} z.2r@Psk
-y&v9OC2-
E ;BPN
//读取保存的下载信息（文件指针位置） b)on A|
private void read_nPos() _KB{J7bs<a
{ JQKC;p
try{ Ow cVPu_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '%zN
int nCount = input.readInt(); D00G1:Ft(T
nStartPos = new long[nCount]; ^wx%CdFm'P
nEndPos = new long[nCount]; r/NSD$-n
for(int i=0;i<nStartPos.length;i++) heE}_,$|
{ ia%z+:G
nStartPos = input.readLong(); 8)^B32
nEndPos = input.readLong(); F_A%8)N
} +Dx1/I
input.close(); j[J5y#
} S=0"f}Jo.
catch(IOException e){e.printStackTrace ();} 7|&e[@B
catch(Exception e){e.printStackTrace ();} EJf#f
} :]P~.PD5,
YSR mt/
!_CX2|
private void processErrorCode(int nErrorCode) Awu$g.
{ !dU9sB2
System.err.println("Error Code : " + nErrorCode); ]pW86L%
} o"rq/\ovv
'|vD/Qf=&
tigT@!`$Y
//停止文件下载 J>rka]*
public void siteStop() 9R9__w;
{ Y3#Nux%
bStop = true; L'zE<3O'3
for(int i=0;i<nStartPos.length;i++) uije#cj#O
fileSplitterFetch.splitterStop(); y[: ~CL
/@ y;iJk;
si_W:mLF{a
} c |>=S)|
} Vy-28icZ`
//负责部分文件的抓取 '3A+"k-}mh
**FileSplitterFetch.java 2O eshkE
*/ K(<$.
package NetFox; 8zhBA9Y#~
"-w^D!C
rRB~=J"
import java.io.*; \HAJ\9*w)
import java.net.*; sX+`wc
kOw=c Gt
J,f/fPaf7
public class FileSplitterFetch extends Thread { z{ptm7
t)YUPDQ@J
<fN; xIB
String sURL; //File URL ev9;Ld
long nStartPos; //File Snippet Start Position "\e:h| .G
long nEndPos; //File Snippet End Position $}t=RW
int nThreadID; //Thread's ID sLb8*fak
boolean bDownOver = false; //Downing is over 1N8;)HLIBJ
boolean bStop = false; //Stop identical Vy__b=ti?
FileAccessI fileAccessI = null; //File Access interface !; IJ
9A~>`.y
QV7,G9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException geksjVwPH
{ ^YGTh0$W
this.sURL = sURL; P?kx
this.nStartPos = nStart; -<_QF82
this.nEndPos = nEnd; 6?N4l ]l
nThreadID = id; O|QUNr9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X0`j-*,FX
} m6^ 5S
lsk_P&M
8p&kLo&
public void run() +R!zs
{ ~g6"'Cya?k
while(nStartPos < nEndPos && !bStop) e}c&LDgU
{ `ncNEHh7K
_a](V6
@Mm/C?#*O
try{ jpRBER_X
URL url = new URL(sURL); *i^`Dw^~y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `OqM8U @
httpConnection.setRequestProperty("User-Agent","NetFox"); ;j{7!GeKa
String sProperty = "bytes="+nStartPos+"-"; lwc5S`"
httpConnection.setRequestProperty("RANGE",sProperty); we3tx{j
Utility.log(sProperty); Ojq]HM6f
OF[?Z
mzWP8Hlw
InputStream input = httpConnection.getInputStream(); l _+6=u
//logResponseHead(httpConnection); i31<].|kA*
`H>b5
t2- ^-g6
byte[] b = new byte[1024]; FZF @
int nRead; [#Y' dFQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RT^v:paNT2
{ ^"9* 'vTtc
nStartPos += fileAccessI.write(b,0,nRead); `1Zhq+s
//if(nThreadID == 1) )tS-.PrA-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .h4\{|
} 4*TmlY
qTT,U9]:
Tk*w3c"$
Utility.log("Thread " + nThreadID + " is over!"); WF2NG;f=
bDownOver = true; rAb&I"\ZY
//nPos = fileAccessI.write (b,0,nRead); >O#grDXb
} 24ux
catch(Exception e){e.printStackTrace ();} iXFP5a>|
} 5rb-U7 /
} 9'nH2,_
)0k']g5
n2{SV
//打印回应的头信息 }s_hD`'
public void logResponseHead(HttpURLConnection con) [84F09HU
{ T-gk<V
for(int i=1;;i++) g JjN<&,
{ er2cQS7R
String header=con.getHeaderFieldKey(i); 9@K.cdRjQ
if(header!=null) \}5p0.=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d,0 }VaY=D
Utility.log(header+" : "+con.getHeaderField(header)); PE"v*9k
else Ya#h'+}
break; paW@\1Q
} :=Kx/E:1
} n((vY.NDV
$bvJTuw
5|I55CTx
public void splitterStop() G_ >G'2
{ FY'ty@|_s
bStop = true; 2 rN ,D(
} "B{ECM;
0:=ZkEEeU
l>6@:nq|R
} x[Im%k
o31Nmy Ni
`y^sITr
/* -F\qnsZ2
**FileAccess.java %0,-.(h
*//文件访问(定位，写) +oc >S
package NetFox; jjzA .8?(7
import java.io.*; ]]0,|My7
6GAaV[])'
1u|V`J)0
public class FileAccessI implements Serializable{ t*G/]
ka"337H
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~rD={&0
RandomAccessFile oSavedFile; 8X$LC
long nPos; k|YWOy@D~
yClx` S(
+Qxu$#
public FileAccessI() throws IOException 71fk.16
{ mee$"Y
this("",0); -%CoWcGP
} (:pq77
5fJ[}~
4)6xU4eBaL
public FileAccessI(String sName,long nPos) throws IOException _[K"gu
{ DgHaOAdU
oSavedFile = new RandomAccessFile(sName,"rw"); 3;[DJ5
this.nPos = nPos; A"v{~
oSavedFile.seek(nPos); Q=uRKh
} T?Fcohz(
g(C|!}ex/
|X19fgk
public synchronized int write(byte[] b,int nStart,int nLen) k]A8% z
{ CO:u1?
int n = -1; 2@=IT0[E\
try{ j;1-p>z
oSavedFile.write(b,nStart,nLen); ccFn.($p?,
n = nLen; Pmg)v!"
} nmU_N:Y
catch(IOException e) Lw1EWN6}_&
{ .|qK+Hnc
e.printStackTrace (); A3N]8?D
} P>ceeoYQuA
H*^\h?s
H( jXI
return n; MPgS!V1
} Ycr3HLJy
{c?JuV4q?
lbdTQ6R
} I` K$E/ns
O,2~"~kF
i':i_kU
/* gi/@j
**SiteInfoBean.java B+d<F[|
*/ F>je4S;
package NetFox; |{r$jZeE
j%u-dr
51C2u)HE
public class SiteInfoBean { `:m!~
'_\;jFAM
6qWdd&1
private String sSiteURL; //Site's URL \c v?^AI
private String sFilePath; //Saved File's Path {`=0 |oP}
private String sFileName; //Saved File's Name K,'*Dz
private int nSplitter; //Count of Splited Downloading File cJo\#cr
vbx6I>\Y
IQ<MyB(
public SiteInfoBean() F~:O.$f]G
{//nSplitter的缺省值为5 ?3ig)J,e[
//default value of nSplitter is 5 g]c[O*NTL
this("","","",5); \0l>q ,
} VGHWNMT
s>k Uh
=gfI!w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vu!d)Fy
{ n79QJl/
sSiteURL= sURL; ;8WZx
sFilePath = sPath; @vL20O.
sFileName = sName; fj7|D'c
this.nSplitter = nSpiltter; -9 !.m
}G o$ \Bk
vb 1@yQ
} R[z`:1lo
a,F&`Wg
8.'#?]a
public String getSSiteURL() KrVcwAcq|1
{ Y2B&go
return sSiteURL; _lzyMEdr
} LMi:%i%\
>Rvx[`|O!m
G22NQ~w8
public void setSSiteURL(String value) Pq*s{
{ D|Iur W1f
sSiteURL = value; %75xr9yOP
} }i{sg#
dzK{ Z
`l2O?U-@
public String getSFilePath() ? J}r
{ !USd9
return sFilePath; 8}H1_y-g[
} ~\x:<)
k#[F`
-jgysBw+Xb
public void setSFilePath(String value) #&v/icz$
{ H&r,FmI@
sFilePath = value; 08X_}97#WF
} j!7`]
U\/5;Txy(
EbeI{-'aF
public String getSFileName() y\N|<+G+
{ XwV'Ha
return sFileName; %r&-gWTQ,
} 4Mk-2 Dx
zR!o{8
gtUUsQ%y.
public void setSFileName(String value) `1{N=!U(&
{ &//wSlL3
sFileName = value; E_KCNn-f
} UAR5^
qE'9QQ>:b
e8YMX&0%
public int getNSplitter() m<L;
{ 6wco&7
return nSplitter; 988]}{w
} ]Jh+'RK\#
1ygpp0IGJ
1c JF/"v
public void setNSplitter(int nCount) iU6Gp-<M,
{ r=yK,d/1
nSplitter = nCount; AiD[SR
} Fnk_\d6Ma
} v]__%_
?+T^O?r|O
\{Q?^E
/* VqL.iZ-
**Utility.java )%!XSsY.N|
*/ u?sVcD[
package NetFox; 0%!rx{f#\
:xKcpY[{
+ [Hh,I7
public class Utility { g$dsd^{O7
JG{j)O|L
:4v3\+T
public Utility() 7d92Pe
{ [{C )LDN
s=?g\oR
8kP3+
} &rkEK4
p4VeRJk%
//线程睡眠 zhY+x<-
public static void sleep(int nSecond) *T0q|P~o%
{ E( us'9c
try{ vkLC-Mzm<
Thread.sleep(nSecond); ;[RZ0Uy=
} nx0K$Ptq
catch(Exception e) E^U0f/5 m
{ sB69R:U;
e.printStackTrace (); 8w({\=
} ;gC|
} fwzb!"!.@
AkOO)0
//日志 \.mI
public static void log(String sMsg) <AJ97MLcc
{ tGB@$UmfU
System.err.println(sMsg); HHqwq.zIy
} Gycm,Cy
dg4vc][
Vf(6!iRP@
public static void log(int sMsg) Wu)>U
{ R *F l8
System.err.println(sMsg); jD7NblX
} jY_T/233d
} !%dN<%Ah
o:V|:*1Q
h$L"8#
/* RmZ]" `
**TestMethod.java a1Qv@p^._b
*/ NH_<q"gT
package NetFox; \c^45<G2qA
y^o@"IYu3
v9T_&
public class TestMethod { r H~" 4
[@4rjGwB
HYmn:?H
public TestMethod() <V>dM4Mkr
{ ///xx/weblogic60b2_win.exe UwC=1g U
try{ _#vrb;.+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y!]CJigpZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ExRe:^yU\
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?k(\ApVHj
fileFetch.start(); ws^4?O
} sUE?v9
catch(Exception e){e.printStackTrace ();} &>H!}"Yk
!Ra*)b"
x`6<m!d`
} ]vuwkn+)
_ 84ut
XV^1tX>f{
public static void main(String[] args) Hty0qr3
{ A/`%/0e
new TestMethod(); %\i9p]=
} n@G[
} >ooZj9:'
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