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)); tF`>.=
} tT'd]
for(int i=0;i<nEndPos.length-1;i++) }V9146
{ kv)LH{
nEndPos = nStartPos[i+1]; <pi q?:ac
} l65'EO|
nEndPos[nEndPos.length-1] = nFileLength; ztb2Ign<
} =Jem.Ph
} =m-_0xo
Ya=QN<
yP[GU| >(
//启动子线程 (U-p&q>z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R_Eu*Quj
for(int i=0;i<nStartPos.length;i++) zSkM8LM2
{ )\^%w9h
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d8Upr1_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hRA.u'M
nStartPos,nEndPos,i); J-u,6c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t,MK#Ko
fileSplitterFetch.start(); )rj.WK.
} BNzL+"W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n1$##=wK]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R HF;AX n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Yh"Z@D[d
nEndPos = " + nFileLength); \ iP[iE=
// fileSplitterFetch[nPos.length-1].start(); zBc7bbK
s"a*S\a;b
P,wFib^1
//等待子线程结束 eKu&_q
//int count = 0; iUl{_vb
//是否结束while循环 #0^QUOp
boolean breakWhile = false; Ro%S_!
]qpcA6%a|
rJNf&x%6
while(!bStop) GWP"i77y0s
{ |y=CmNG,
write_nPos(); (EohxLl!p
Utility.sleep(500); OFUN hbg
breakWhile = true; dQizM^j
fM2[wh@
bfa5X<8
for(int i=0;i<nStartPos.length;i++) ZJw92Sb
{ \,(tP:o
if(!fileSplitterFetch.bDownOver) R>Zn$%j\
{ 4.VEE~sH$
breakWhile = false; 2TAy'BB;)
break; _q8s 7H
} X>Xpx<RY!
} kfmIhHlYQ
if(breakWhile) <v{jJ7w
break; ,lN!XP{M6w
OTV)#,occ
:I&iDS>u1
//count++; 4P`\fz
//if(count>4) sRoZvp5
// siteStop(); WUqAPN
} X;}_[=-
sI^1c$sBN
2y<d@z:K
System.err.println("文件下载结束！"); bNL E=#ro
} }hBv?B2/1
catch(Exception e){e.printStackTrace ();} 0+S:2i/G
} WMI/Y9N
xr6Q5/p1
v}cm-_*v
//获得文件长度 wOa_"
public long getFileSize() ,*C^ixNE
{ M{(Y|3W
int nFileLength = -1; P-vA.7
try{ t zV"|s=o
URL url = new URL(siteInfoBean.getSSiteURL()); g@j:TQM_0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \64(`6>
httpConnection.setRequestProperty("User-Agent","NetFox"); 2_Pe/
-<<!eH
i!Ne<Q
int responseCode=httpConnection.getResponseCode(); \SMH",u
if(responseCode>=400) t@4vEKw?.X
{ E8-p ,e,
processErrorCode(responseCode); "#m*`n
return -2; //-2 represent access is error w=f8UtY9@A
} ^Xb!dnT.*a
bUWtlg
1hMk\ -3S
String sHeader; I#A`fJ
*tP,Ol
JLG5`{
for(int i=1;;i++) n*;mFV0s
{ 16aaIK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !BQ!]u
//Utility.log(in.readLine()); ;eA~z"g
sHeader=httpConnection.getHeaderFieldKey(i); S)[2\Z{**T
if(sHeader!=null) Xt~/8)&
{ bqLv81V
if(sHeader.equals("Content-Length")) _ !Ph1
{ ]_-$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wTTQIo60
break; J7E/2Sl
} 61C&vm
} p]aIMF_
else |a"(Ds2U
break; |%M%j'9
} d&U;rMEv
} oiR`\uY
catch(IOException e){e.printStackTrace ();} #u2PAZ@qd
catch(Exception e){e.printStackTrace ();} }M9'N%PU
yBr{nFOgdY
S@*@*>s^
Utility.log(nFileLength); h2tzv~
\zoJr)
o-(jSaH :;
return nFileLength; xr?r3Y~^e
} R'80{
JUXK}0d%eN
o= 8yp2vG
//保存下载信息（文件指针位置） 4<O[d
private void write_nPos() %_3{Db`R>
{ K+GjJ8
try{ \(A>~D8Fo
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?s_q|d_
output.writeInt(nStartPos.length); Lv5AtZl}
for(int i=0;i<nStartPos.length;i++) ^^%*2^
{ 7"S|GEs:
// output.writeLong(nPos); OrRve$U*|
output.writeLong(fileSplitterFetch.nStartPos); g xLA1]>{
output.writeLong(fileSplitterFetch.nEndPos); Z> &PM06
} QVFa<>8/md
output.close(); JEAqSZak#
} y[$e]N
catch(IOException e){e.printStackTrace ();} RSkpf94`
catch(Exception e){e.printStackTrace ();} r2hm`]\8M
} P|6m%y
i\PN
j5RMS V
//读取保存的下载信息（文件指针位置） D)!k
private void read_nPos() b>waxQxjS
{ #}vcffgZ
try{ Cf10 ud
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WIhf*LF"
int nCount = input.readInt(); ?Dfgyz
nStartPos = new long[nCount]; *X)OdU
nEndPos = new long[nCount]; B)c.`cfr*\
for(int i=0;i<nStartPos.length;i++) #6YNgJNk
{ G[wa,j^hu
nStartPos = input.readLong(); !WIL|\jbh
nEndPos = input.readLong(); lvFHr}W
} &XZ>}^lD^
input.close(); Fs=nAn#
} *F9uv)[kz
catch(IOException e){e.printStackTrace ();} [` i;gx[^
catch(Exception e){e.printStackTrace ();} 4e5Ka{# <
} 00$W>Gr
-MU^%t;-
CE+\|5u W
private void processErrorCode(int nErrorCode) c8u&ev.U
{ jy1*E3vQ
System.err.println("Error Code : " + nErrorCode); DLz~$TF^
} %iX+"
uS&bfx2
/Db~-$K
//停止文件下载 1 8&^k|
public void siteStop() S]9xqiJW
{ Q"(i
bStop = true; yX)2 hj:s
for(int i=0;i<nStartPos.length;i++) '8W}|aF
fileSplitterFetch.splitterStop(); LS \4y&J40
;=E3f^'s
KQ2]VN"?_
} E.BMm/WH
} 'DKP-R"
//负责部分文件的抓取 {j(,Q qB;f
**FileSplitterFetch.java L>PpXTWwy
*/ gfp#G,/B
package NetFox; `5gcc7b
C f<,\Aav
T{ojla(
import java.io.*; h?idRaN_
import java.net.*; b0 5h,
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ABx0IdOcI
public class FileSplitterFetch extends Thread { {Ji[d.cY
fdPg{3x*k
UyvFR@
String sURL; //File URL <7)@Jds\
long nStartPos; //File Snippet Start Position /FQumqbnt
long nEndPos; //File Snippet End Position gsZCWT
int nThreadID; //Thread's ID 2B*9]AHny
boolean bDownOver = false; //Downing is over ]pFYAe ?
boolean bStop = false; //Stop identical u9?85
FileAccessI fileAccessI = null; //File Access interface 7o;}"Y1
uODpIxN
H7R1GaJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vZk+NS<
{ \=nY&Ml
this.sURL = sURL; J%%nv5y
this.nStartPos = nStart; @(ev``L5g
this.nEndPos = nEnd; l3.HL> o
nThreadID = id; 2"2b\b}my
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xKIm2% U9
} 7gvkd+-*
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TMq\}k-I5
public void run() [P"#?7 N
{ *P9)M%
while(nStartPos < nEndPos && !bStop) (m@({
{ 6Siz9
*)"`v]
(LGx;9S?
try{ "Z#&A
URL url = new URL(sURL); Vw+U?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )|*HkdF`
httpConnection.setRequestProperty("User-Agent","NetFox"); QQ pe.oF
String sProperty = "bytes="+nStartPos+"-"; {E>kFeg
httpConnection.setRequestProperty("RANGE",sProperty); 3F<My+J
Utility.log(sProperty); rrmr#a
9.>v ;:vL
L0Xb^vx}m
InputStream input = httpConnection.getInputStream(); T?Hs_u{
//logResponseHead(httpConnection); /}(w{6C
S_1R]n1/
l'mgjv~
byte[] b = new byte[1024]; 5a_1x|Fhi
int nRead; Dy5'm?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z0doLb^!
{ vrQ/Yf:\B
nStartPos += fileAccessI.write(b,0,nRead); c"6<p5j!
//if(nThreadID == 1) ,7<5dIdZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ECQ>VeP
} #_|6yo}
bT0CQ_g21
L`3 g5)V
Utility.log("Thread " + nThreadID + " is over!"); Fvl_5l
bDownOver = true; h=?#D0
//nPos = fileAccessI.write (b,0,nRead); eSJ5YeY)
} ^ WidA-
catch(Exception e){e.printStackTrace ();} 0~)cAKus
} YY'46
} qMKXS,s
= gOq >`
..;}EFw5
//打印回应的头信息 ub7|'+5
public void logResponseHead(HttpURLConnection con) /+iU1m'(
{ yB,$4:C
for(int i=1;;i++) 4E<iIA\x
{ 6[w_/X"
String header=con.getHeaderFieldKey(i); D O#4E<]5
if(header!=null) I6X_DPY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %^kBcId
Utility.log(header+" : "+con.getHeaderField(header)); |3QKxS0
else A^*0{F?,)
break; &Z#g/Hc
} NRgNh5/
} 'z>|N{-xG
FK{Vnj0
R~PD[.\u
public void splitterStop() yC(xi"!
{ hZ[,.
bStop = true; M9M~[[
} R:fERj<s
hCuUX)>Bt
j/ow8Jmc*
} ,_F@9Up
^FIpkhw
#2^eGhwnI
/* 2mRm.e9?
**FileAccess.java ]>B>.s
*//文件访问(定位，写) <My4)3
package NetFox; 1-.6psE
import java.io.*; D!^&*Ia?2
*@^9]$*$
Mj2`p#5wKh
public class FileAccessI implements Serializable{ lhZXq!2p
>;:235'(M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GHaD32
RandomAccessFile oSavedFile; XOe)tz L
long nPos; 4"at~K` Q
a9}7K/Y=d
p.~hZ+ x_
public FileAccessI() throws IOException *6IytWOX5
{ 5%Hw,h
this("",0); =ss(~[
} ] -iMo4H
avxr|uk
FN0)DN2d}
public FileAccessI(String sName,long nPos) throws IOException waT'|9{
{ THEpW{.E
oSavedFile = new RandomAccessFile(sName,"rw"); ' d' Dlg
this.nPos = nPos; KW`^uoY$
oSavedFile.seek(nPos); o"wvP~H
} "tdF#>x
{wA(%e3_
EX@wenR
public synchronized int write(byte[] b,int nStart,int nLen) @ LPs.e
{ R2,Z`I
int n = -1; wIeF(}VM
try{ /u?ZwoTzY
oSavedFile.write(b,nStart,nLen); vLCyT=OB`
n = nLen; ,6@s N'c
} %dn!$[D@
catch(IOException e) z{$2bV
{ w>S;}[fM
e.printStackTrace (); 7n}$|h5D
} lrQNl^K}=
?gYQE&M !
*62Cf[a
return n; = j)5kY`
} [/E|n[Bx
wB'GV1|jL
'rl?'~={p
} e\)r"!?H`
-A1@a=q
=2XAQiUR\
/* -,:^dxE'
**SiteInfoBean.java }ZqnsLu[)
*/ b,h@.s
package NetFox; T&'p5h=l
@qUgp*+{
~ p~
public class SiteInfoBean { 6K Cv
)>"|<h.2]
tW-wO[2
private String sSiteURL; //Site's URL " l;=jk]
private String sFilePath; //Saved File's Path 7!sR%h5p
private String sFileName; //Saved File's Name :Eb=jWA
private int nSplitter; //Count of Splited Downloading File s$g3__|Y
p`qy57
@V}!elV
public SiteInfoBean() E|_J
{//nSplitter的缺省值为5 w 3kX!%a:
//default value of nSplitter is 5 LS:^K
this("","","",5); 7H])2:)
} u!CcTE*
GD-L0kw5
9z#z9|hj)3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N++ ;}j
{ E%%iVFPX
sSiteURL= sURL; utzf7?nIS
sFilePath = sPath; >Py:9~g,
sFileName = sName; )Szn,
this.nSplitter = nSpiltter; + *)Kyk
xYp-Y"a.
9ERyr1-u v
} &v)/mc7D
do[w&`jw8
x1`4hB
public String getSSiteURL() `eEiSf
{ w!_6*
return sSiteURL; ;UpdkY 1
} u u$Jwn!S
Yr)<1.K4,M
<sTY<iVR
public void setSSiteURL(String value) 7TtDI=f
{ yz7Fe
sSiteURL = value; 7u`:e,'
} Og-v][
oL U!x
hsAk7KC
public String getSFilePath() sa?s[
{ .^xQtnq
return sFilePath; 0e +Qn&$#4
} laRn![[
#EA` |
a9_KoOa.H
public void setSFilePath(String value) 1lYQR`Uh
{ ~KYA{^`*
sFilePath = value; 0" F\V
} ku)/ 8Z`$
HDi_|{2^
B7.<A#y2
public String getSFileName() 7Hg;SK6t0
{ :#OaE,
return sFileName; 9K>~9Za
} zeshM8=
5cj&D74o
O/.8;.d;4Y
public void setSFileName(String value) 0nPg`@e.
{ Ca["tks
sFileName = value; .npD<*
} >r>pM(h
c?*x2Vk
KK?R|1VK9
public int getNSplitter() u p zBd]
{ ]E|E4K6g
return nSplitter; q*!Vyk
} I6i qC"BK
jZk dTiI
?aQVaw&L!7
public void setNSplitter(int nCount) rRXF@
{ -amNz.`[PR
nSplitter = nCount; *JOp)e0b
} &,QBJx<#
} gm$<U9L\v
;EsfHCi)
&`}d;r|yn1
/* 79uAsI2-Y
**Utility.java ~zoZ{YqP
*/ S;"$02]
package NetFox; #Cb~-2:+7
`j4OKZ
r*c x_**
public class Utility { =%S*h)}@
QsPZ dC
-sx=1+\nf
public Utility() .7HEI;4
{ WM0-F@_
D1V^DbUm_
5Nt9'"
} sWq@E6,I
"`V:4uz
//线程睡眠 [33=+Ca
public static void sleep(int nSecond) #[]B: n6
{ ]4Q~x
try{ # ';b>J
Thread.sleep(nSecond); ),@m 3wQ
} Cy5M0{
catch(Exception e) b2^O$l
{ c3)6{
e.printStackTrace (); }-@h H(
} $e%m=@ga
} RijFN.s
R=C+]
//日志 g6H`uO
public static void log(String sMsg) brdY97s4
{ n],"!>=+
System.err.println(sMsg); 7Q|v5@;pU
} \98|.EG
{A\y4D@
pYj}
public static void log(int sMsg) hM[I}$M&O
{ 1`9'.w+r
System.err.println(sMsg); }0Fu
} d&X <&)a7
} A<-3u
+ 7nA; C
yG<Q t+D
/* ^= '+#|:
**TestMethod.java $*7AG
*/ 7G%^8 ce{!
package NetFox; v"sN K
#&Zj6en}M]
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public class TestMethod { r#c+{yY
`L"l{^cH
{qFAX<{D
public TestMethod() [?n}?0
{ ///xx/weblogic60b2_win.exe Vah.tOU
try{ Zzv,p
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (kJ"M4*<F'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QKhvP>
SiteFileFetch fileFetch = new SiteFileFetch(bean); qbo W<W<H1
fileFetch.start(); 960rbxKy3
} fn.}LeeS>
catch(Exception e){e.printStackTrace ();} t7/a5x
XtIY8wsP
FD^s5>"Y+
} 0{>P^z
Lu~M=Fh
M!iYj+nrP
public static void main(String[] args) _UUp+Hz
{ tH9BC5+r}
new TestMethod(); `BY&&Bv#?
} &uxwz@RC0
} Mh5 =]O+
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