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)); Z@(m.&ZRx
} ((Uw[8#2`
for(int i=0;i<nEndPos.length-1;i++) 7fE U5@
{ {?X:?M_
nEndPos = nStartPos[i+1]; y8%QS*
} tK7v&[cI
nEndPos[nEndPos.length-1] = nFileLength; wjy<{I
} ]Ub"NLYV
} grVPu! B;
A9Kt^HR
BMi5F?Q'G
//启动子线程 b,hRk1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xlIVLv6dO
for(int i=0;i<nStartPos.length;i++) dj-/%MU
{ T\v~"pMu*0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C:r3z50
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ({$>o]<h
nStartPos,nEndPos,i); vFwhe!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _kEU=)Xe
fileSplitterFetch.start(); me@k~!e"z
} ?'I-_9u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BK]5g[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FQ_a=v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <P@ "VwUX
nEndPos = " + nFileLength); Kt3T~k
// fileSplitterFetch[nPos.length-1].start(); {Ri6975
2=IZD `{!
s.$:.*k
//等待子线程结束 1$_|h@
//int count = 0; =C#22xqQ.
//是否结束while循环 -J":'xCP!
boolean breakWhile = false; Lrjp
z"\<GmvB
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while(!bStop) p54e'Zb
{ Lo*vt42{4
write_nPos(); q"0_Px9P
Utility.sleep(500); ^Ycn&`s
breakWhile = true; v`&>m'
4D)M_O
+OaBA>Jh9
for(int i=0;i<nStartPos.length;i++) gY {/)"
{ U_sM==~
if(!fileSplitterFetch.bDownOver) }Jo}K)>!
{ fA)4'7UT
breakWhile = false; P" aw--f(
break; =xjtPmZ5X
} G?+0#?'Y
} ~P fk
if(breakWhile) \=c@
break; )0o|u>
XyYP!<].C
K!a7Hg
//count++; {W'{A
//if(count>4) NCp]!=uM;
// siteStop(); (j&7`9<5
} f?lnBvT|b
L-`?=- 9`
%Y=
System.err.println("文件下载结束！"); Hy1pIUsx
} ~,m5dP#[bV
catch(Exception e){e.printStackTrace ();} Um!LF"Z
} D\Fu4Eg
t vp kc;
8vx#QU8E/
//获得文件长度 xf3;:soC
public long getFileSize() R-6km Tex>
{ QE6L_\l
int nFileLength = -1; J9&#);(
try{ awgS5We|
URL url = new URL(siteInfoBean.getSSiteURL()); _iH:>2p5R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lm8<0*;,
httpConnection.setRequestProperty("User-Agent","NetFox"); ({<qs}H"
| MXRNA~
UYH&x:WEd
int responseCode=httpConnection.getResponseCode(); o4H'
if(responseCode>=400) ._p^0UxT
{ !JQ'~#jKN
processErrorCode(responseCode); chur(@Af
return -2; //-2 represent access is error R:y u
} Q"k #eEA
_|>bOI
_#yd0E
String sHeader; Of;$ VK'
a?X#G/)
vv1W<X0e<
for(int i=1;;i++) & &:ZY4`
{ 7&2CLh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /h,-J8[
//Utility.log(in.readLine()); 2NF#mWZ(s
sHeader=httpConnection.getHeaderFieldKey(i); es1'z.UJ
if(sHeader!=null) -+n?Q;
{ 7#sb},J{
if(sHeader.equals("Content-Length")) ^ux"<?
{ OSkBBo]~z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gmCB4MO
break; V4. }wz_Y
} \eCQL(_
} Wdp4'rB
else ]4[^S.T=
break; #{~3bgY
} gcF V$
} ;m}o$`
catch(IOException e){e.printStackTrace ();} Lu[xoQ~I
catch(Exception e){e.printStackTrace ();} 15cgmZsS
`7Dj}vVu
$uUJV% EX
Utility.log(nFileLength); yb-/_{Y
eR!K8W
^20x\K
return nFileLength; #1[Q?e4,0
} M(.]?+
;f[@zo><r
H8$";T(I
//保存下载信息（文件指针位置） |"Fm<
private void write_nPos() QD^"cPC)mM
{ t_iZ\_8
try{ 7VA6J-T
output = new DataOutputStream(new FileOutputStream(tmpFile)); rm!.J0 X
output.writeInt(nStartPos.length); ^"4u1
for(int i=0;i<nStartPos.length;i++) HE*P0Yf=
{ x=3+@'
// output.writeLong(nPos); }J] P`v
output.writeLong(fileSplitterFetch.nStartPos); XaYgl&x'!x
output.writeLong(fileSplitterFetch.nEndPos); i; 3qMBVY~
} fVxRK\a\\
output.close(); l?zWi[Zf
} 6'JP%~QlS
catch(IOException e){e.printStackTrace ();} C<hb{$@
catch(Exception e){e.printStackTrace ();} \2AXW@xE
} TmdRB8N
0@2pw2{Ru
hJ0m;j&4y
//读取保存的下载信息（文件指针位置） fZt3cE\
private void read_nPos() &:Sb$+z
{ 23gJD8i8
try{ #*;Nb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J.pe&1
int nCount = input.readInt(); * TR~>|
nStartPos = new long[nCount]; } bEu+bZ
nEndPos = new long[nCount]; kA(q-Re$B*
for(int i=0;i<nStartPos.length;i++) AK5$>Pkvk
{ mNApFwZ
nStartPos = input.readLong(); >Av%[G5=h#
nEndPos = input.readLong(); J9`[Qy\
} Q)ZkUmW
input.close(); 0:k ~lz
} *,p16"Q;
catch(IOException e){e.printStackTrace ();} Vr<ypyC
catch(Exception e){e.printStackTrace ();} D(gpF85t
} -QP&A >]7
gfAVxMg
'gv7&$X}4
private void processErrorCode(int nErrorCode) g bwg3$!9
{ !Mk:rO-L
System.err.println("Error Code : " + nErrorCode); ,__|SnA.
} s`"ALn8m
.X(ocs$}
da53XEF&
//停止文件下载 ^p!bteA>
public void siteStop() s*W)BK|+?
{ ]<\; -i)
bStop = true; Ow7I`#P
for(int i=0;i<nStartPos.length;i++) >zWVM1\\j
fileSplitterFetch.splitterStop(); 9TILrK
"ktC1y1
b{Kw.?85
} [EV}P&U
} N0G-/
//负责部分文件的抓取 z/t:gc.
**FileSplitterFetch.java /WIHG0D
*/ 7<%Rx19L*
package NetFox; LYX\#
5s2334G
\|9KOulr
import java.io.*; r&-Ir3[
import java.net.*; ld*RL:G
Rd.[8#7VE
G0eJ<*|_ 3
public class FileSplitterFetch extends Thread { Ig6>+Mw
mLn =SU{#
q7%eLJ
String sURL; //File URL 5CuK\<
long nStartPos; //File Snippet Start Position uH-*`*
long nEndPos; //File Snippet End Position T4{&@b 0*
int nThreadID; //Thread's ID {bvm83{T
boolean bDownOver = false; //Downing is over }qOC*k:
boolean bStop = false; //Stop identical U-EX)S^T[{
FileAccessI fileAccessI = null; //File Access interface Epm=&6zf
3fJwj}wL
E5 0$y:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }AfK=1yOa
{ N:@C% UW}
this.sURL = sURL; E0*'AZi&
this.nStartPos = nStart; 4r [Tpb
this.nEndPos = nEnd; <ST#< $%
nThreadID = id; k&P_ c
fileAccessI = new FileAccessI(sName,nStartPos);//定位 GX lFS#`
} 'yM)>]u"
mckrR$>
"@I"0OA
public void run() cuP5cL/Y
{ S:"t]gbF =
while(nStartPos < nEndPos && !bStop) %.R_[.W
{ ngN_,x7yc
ZR'q.y[k)
U< p kg
try{ <`q|6XWL
URL url = new URL(sURL); _k@{> ?(a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q(KLx)
httpConnection.setRequestProperty("User-Agent","NetFox"); 0fPqO2
String sProperty = "bytes="+nStartPos+"-"; %?EOD=e=
httpConnection.setRequestProperty("RANGE",sProperty); *<!W k\
Utility.log(sProperty); =`X@+~%-
G K @]61b
f.=4p^
InputStream input = httpConnection.getInputStream(); pstQithS
//logResponseHead(httpConnection); SJ-g2aAT
hoihdVjv
97Qng*i
byte[] b = new byte[1024]; Sn/~R|3XA7
int nRead; GJItGq`)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '.@R_sj
{ j]<T\O>t>
nStartPos += fileAccessI.write(b,0,nRead); 0\jOg
//if(nThreadID == 1) 3Fn26Rij
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7 v<$l
} szwXr
K`FgU7g{
^[CD-#
Utility.log("Thread " + nThreadID + " is over!"); !DCJ2h%E[_
bDownOver = true; m=S[Y^tR
//nPos = fileAccessI.write (b,0,nRead); u hP0Zwn
} O`dob&C
catch(Exception e){e.printStackTrace ();} :u{0M&
} 5e,Dk0d
} W&4`eB/4}
v-)eT
]T(O;y*m
//打印回应的头信息 "=<lPi
public void logResponseHead(HttpURLConnection con) BQBO]<99
{ h ;5 -X7
for(int i=1;;i++) +c\s%Gzrh
{ vd /_`l.D
String header=con.getHeaderFieldKey(i); KX)xCR~
if(header!=null) z>i D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x[}e1sXXs
Utility.log(header+" : "+con.getHeaderField(header)); C)z[Blt
else &u"*vG (U[
break; vO{ijHKE
} ?/)5U}*M0T
} FzpWT-jnDd
{zUc*9
"\BP+AF
public void splitterStop() Whd4-pR8
{ ".xai.trr
bStop = true; :Rt5=0x
} Ai->,<Ig]
;^DUtr ;
W'XMC"
} ,mYoxEB kl
!Y]}&pUP
+ZE&]BO{
/* @?Y^=0
**FileAccess.java \Zf&&7v
*//文件访问(定位，写) Ip4NkUI3T
package NetFox; sp**Sg)
import java.io.*; g@Ni!U"_c
ITc/aX
&"tce6&
public class FileAccessI implements Serializable{ r$v?[x>+K
[k'Ph33c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c(#`z!FB
RandomAccessFile oSavedFile; <YeF?$S}
long nPos; rY!uc!
DAu|`pyC%
Xq>e]#gR
public FileAccessI() throws IOException 4nl>&AV
{ z}bnw2d]
this("",0); {sm={q
} dBlOU.B
U*&ZQw
)i_FU~ LRq
public FileAccessI(String sName,long nPos) throws IOException INbjk;k
{ m]-8?B1`Y
oSavedFile = new RandomAccessFile(sName,"rw"); (C-z8R Z6
this.nPos = nPos; WQ5sC[&
oSavedFile.seek(nPos); ^Nsl5
} uAvs
mLkZ4OZ
z)VIbEy
public synchronized int write(byte[] b,int nStart,int nLen) "ZyHt HAK
{ P/I{q s
int n = -1; 3yKI2en"
try{ AVyZ#`,
oSavedFile.write(b,nStart,nLen); MW`a>'0t?
n = nLen; 7 $9fGo
} "}OFwes
catch(IOException e) q5vs;,_ |
{ /2@%:b)
e.printStackTrace (); 0X0D8H(7Q
} ?Nh%!2n
=` i 7?
'o7PIhD"
return n; phc1AN=[E
} #`p>VXBj!
GVl u4
r0X2cc
} o`77gkLO
,g,jY]o
@zJI0_Bp
/* *c AoE l
**SiteInfoBean.java `>sqP aD
*/ DYWC]*
package NetFox; ,{Ab=xV
R$fna[Xw@/
*2AQ'%U~
public class SiteInfoBean { /B!m|)h5~
Dz50,*}J
s^oNQ}
private String sSiteURL; //Site's URL \9}5}X_x.
private String sFilePath; //Saved File's Path @qC:% |>
private String sFileName; //Saved File's Name Wl#^Eu\g1W
private int nSplitter; //Count of Splited Downloading File {;4PP463
Qi[D&47XO
.u*].As=
public SiteInfoBean() mNeW|3a
{//nSplitter的缺省值为5 eurudl
//default value of nSplitter is 5 2T3DV])Q
this("","","",5); o 4b{>x
} KB"iF}\P0
$0*47+f
$dnHUBB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Nb#7&_f=
{ WsV3>=@f
sSiteURL= sURL; ) ,hj7
sFilePath = sPath; _#4,&bh8
sFileName = sName; ,\M_q">npc
this.nSplitter = nSpiltter; :7ngVc
# 0!IUSa
"B}08C,?
} 'sF563kE
d>`(.qvxR
if}]8
public String getSSiteURL() -7O/ed+
{ `az`?`i7
return sSiteURL; +lT]s#Fif
} S1zw'!O5
LgNNtZ&F
~yi&wbTjM
public void setSSiteURL(String value) 5lxq-E3
{ lkZC?--H
sSiteURL = value; 1Kh?JH
} 7h]R{_
Kk98FI0]
erP>P
public String getSFilePath() y:OywIi(
{ W{+0iAYnp
return sFilePath; ptv4v[gQ
} y+scJ+<
$cOD6Xr)d
1:!rw,Jzl`
public void setSFilePath(String value) R$fIb}PDr
{ OZ;E&IL
sFilePath = value; >1U@NK)HfY
} D:ugP,
otVyuh
_Af4ct;ng
public String getSFileName() :3>yr5a7-
{ L[G\+
return sFileName; uHro%UAd
} ^X;Xti
~fp+@j-A
3t8H?B12ow
public void setSFileName(String value) /Z " 4[
{ gqD^Bs'VF
sFileName = value; JGDUCb~
} m90R8 V
(I[h.\%
'(pdk
public int getNSplitter() d+2O^of:T
{ J8v:a`bX&
return nSplitter; q7 oR9
} [E~,>Q
EjX'&"3.
!en F8a
public void setNSplitter(int nCount) #KNq:@wp6
{ gZEA;N:H%<
nSplitter = nCount; :5K~/=6x
} f76|
} 6>BDA?
kw^Dp[8X
@!a]qAt
/* T7,Gf({
**Utility.java v~2XGm
*/ Df,VV+
package NetFox; 9;Pu9s[q2
ls"\YSq$
V=4u7!ha
public class Utility { ;k&k#>L!K
#Wm@&|U
]t*P5
public Utility() FV6he[,
{ 7k t7^V<
=E}%>un
`{|}LFS>
} NVA`t]gn
'Tf#S@o
//线程睡眠 30(m-D$K>9
public static void sleep(int nSecond) r{!"%03H_
{ %M)oHX1p
try{ Cb%.C;q
Thread.sleep(nSecond); BdoC6H
} v*'iWHCl,
catch(Exception e) ioY\8i
{ x$5nLS2.
e.printStackTrace (); ;*4tVp,
} t6%xit+
} FP'u)eU&3
SeZT4y*=
//日志 GE~(N N
public static void log(String sMsg) (-'0g@0UA
{ aC8,Y$>?E`
System.err.println(sMsg); u};]LX\E
} $|cp;~ 1
&Rl3y\ r
af?\kBm
public static void log(int sMsg) @Wx`l) b
{ [rUh;_b\D
System.err.println(sMsg); X|1_0
} 4'{hI;&a&
} 3^A/`8R7K
,F?~'-K
sPE)m_u
/* F'UguC">
**TestMethod.java V:F+HMBk
*/ \+?,c\x
package NetFox; y800(z
csFJ5
-l40)^ E}
public class TestMethod { dp UdFuU"
LA;V}%y?
~^%0V<*-}
public TestMethod() 2iR:*}5
{ ///xx/weblogic60b2_win.exe tJh3$K\
try{ v/aPiFlw
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |auX*hb9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +Jo 3rX'`
SiteFileFetch fileFetch = new SiteFileFetch(bean); Vyq#p9Q
fileFetch.start(); -lP )
} w`.T/
catch(Exception e){e.printStackTrace ();} X#p o|,Q
h=K36a)
*< $c =
} re ]Ste
hs{&G^!jo
<wUD
public static void main(String[] args) (?!(0Ywbg
{ \f /!
new TestMethod(); M}=s3[d(,
} #7-kL7 MK]
} \8>
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