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)); N@g+51ye
} l-&f81W
for(int i=0;i<nEndPos.length-1;i++) -nW-I\d%
{ \iFE,z
nEndPos = nStartPos[i+1]; (ZYOm
} @cON"(
nEndPos[nEndPos.length-1] = nFileLength; dZ*o H#B
} LBg#KQ@
} +]#>6/2q
V47Fp
y$WS;#
//启动子线程 jVDNThm+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]zO]*d=m
for(int i=0;i<nStartPos.length;i++) g!$ "CX%8
{ {RK#W~h
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rTH@PDk>)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x{rt\OT
nStartPos,nEndPos,i); .#X0P=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HwHI$IB
fileSplitterFetch.start(); )~6974
} MmX42;Pw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U+KbvkX wj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MIgIt"M jz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SNQ+ XtoO
nEndPos = " + nFileLength); m ]\L1&
// fileSplitterFetch[nPos.length-1].start(); &+\wYa,
;(XSw%Y H
o}T]f(>}
//等待子线程结束 IAfYlS#<yD
//int count = 0; , Le_PJY)
//是否结束while循环 tQ/U'Ap&
boolean breakWhile = false; er53?z7zP.
.}tL:^'~o
HV}NT~
while(!bStop) Y !`H_Qo
{ ;j$84o{
write_nPos(); *q^'%'
Utility.sleep(500); ,"D1!0
breakWhile = true; G 5)?!
R{T4AZ@,'
6c2fqAF>i
for(int i=0;i<nStartPos.length;i++) Ct B> s7
{ g$A1*<+
if(!fileSplitterFetch.bDownOver) W?@ ;(k
{ sIyLW
breakWhile = false; U}UIbJD*=
break; "PX~Yc
} |PWLFiT(>
} XLtuck
if(breakWhile) sx22|j`)V
break; 4o%hH
toF@@%
(vY10W{
//count++; L9x,G!
//if(count>4) F*a+&% Q
// siteStop(); t<e?f{Q5
} kr3ZqMfeI
l!oU9
u", [ulP
System.err.println("文件下载结束！"); pPIH`Iq
} YXmLd'F^3
catch(Exception e){e.printStackTrace ();} f`?|A
} U8moVj8w1
`aCcTs7~]p
Q[}mH: w
//获得文件长度 =14pEe
public long getFileSize() =~R0U
{ Ar|_UV>Zf
int nFileLength = -1; Wjj'yqBO^
try{ }b1P!xb!A
URL url = new URL(siteInfoBean.getSSiteURL()); $Q?UyEi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Lg'z%pi
httpConnection.setRequestProperty("User-Agent","NetFox"); Q 5Ln'La$
n.XT-X^
-q-%)f
int responseCode=httpConnection.getResponseCode(); k(T/ydrw
if(responseCode>=400) #*~#t4S-
{ ^D!UF(H
processErrorCode(responseCode); akaQ6DIdG
return -2; //-2 represent access is error aa$+(
} HbCM{A9
kg_TXB
Z{%h6""
String sHeader; }APf^Ry
f9;M"Pd
$[IuEdc/
for(int i=1;;i++) _v_ak4m>
{ .rwZ`MP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,UY],;ib
//Utility.log(in.readLine()); dD#A.C,Rz
sHeader=httpConnection.getHeaderFieldKey(i); S]k<Ixvf
if(sHeader!=null) lx%<oC+M
{ d kPfdK}G
if(sHeader.equals("Content-Length")) qF>}"m
{ ).xQ~A\.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v\Q${6kEtx
break; SC'fT!
} 1;SWfKU?.
} !sUo+Y
else S_C+1e
break; 94H 6`
} d'PjO-"g
} + -U7ogs
catch(IOException e){e.printStackTrace ();} ^G=s<pp
catch(Exception e){e.printStackTrace ();} yY8q{\G
~Q5L)}8N
xqIt?v2c
Utility.log(nFileLength); $l Y
Fz-Bd*uS
o ;.j_
return nFileLength; -$t#AYKz
} NCBS=L:
]5B5J
k|1/gd5
//保存下载信息（文件指针位置） FhW\23OC
private void write_nPos() 5v8_ji#l[
{ 4h?[NOA"
try{ 9=Y-w s
output = new DataOutputStream(new FileOutputStream(tmpFile)); @99@do|C
output.writeInt(nStartPos.length); ~p^6
for(int i=0;i<nStartPos.length;i++) {i3]3V"Xp
{ `5Q0U%`W
// output.writeLong(nPos); /z`LB
output.writeLong(fileSplitterFetch.nStartPos); zuXJf+]
output.writeLong(fileSplitterFetch.nEndPos); UP^{'eh
} nCJ)=P.d
output.close(); G,%R`Xns
} NEJxd%-
catch(IOException e){e.printStackTrace ();} Yaht<Hy
catch(Exception e){e.printStackTrace ();} Ee d2`~
} EC|t4u3
r:<UV^; 9l
X&pK#=
//读取保存的下载信息（文件指针位置） E\5t&jZr
private void read_nPos() !Mceg
{ |I6\_K.=L
try{ WM~@/J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2{% U\^-
int nCount = input.readInt(); dk# LAm0<
nStartPos = new long[nCount]; `q".P]wtKN
nEndPos = new long[nCount]; #1+1q{=Z<
for(int i=0;i<nStartPos.length;i++) hr(E,TAe
{ {|bf`
nStartPos = input.readLong(); NvQN
nEndPos = input.readLong(); hxGZ}zq*S
} 6j+_)7.V
input.close(); .9PPWY;H
} RdRF~~R%
catch(IOException e){e.printStackTrace ();} q0&g.=;
catch(Exception e){e.printStackTrace ();} 7NE"+EP\{2
} Rra<MOR
".Luc7
UW_fn
private void processErrorCode(int nErrorCode) =E,^ +`M
{ *xI0hFJIM
System.err.println("Error Code : " + nErrorCode); GMyzQ]@}
} e3}`]
V*"-@
2r]80sWY
//停止文件下载 l`M{Ravvn*
public void siteStop() fczId"
{ |gg6|,Bt4
bStop = true; gDa}8!+i
for(int i=0;i<nStartPos.length;i++) =`Pgo5A
fileSplitterFetch.splitterStop(); sEm-Td+A5
}w}2'P'T
JmjqA Dex
} Ko|nF-r_
} 9@/X;zO
//负责部分文件的抓取 6w|s1!Bl
**FileSplitterFetch.java T%B&HsH
*/ #`?B:
package NetFox; 7VduewKX8
yY_Zq\
p"\Z@c
import java.io.*; JvX]^t/}
import java.net.*; .zZee,kM
s]@()?.E$
b"DaLwKkz
public class FileSplitterFetch extends Thread { L3/m}AH,
F !g>fIg
o'O;69D]tX
String sURL; //File URL LVP2jTz
long nStartPos; //File Snippet Start Position 38#BINhBt
long nEndPos; //File Snippet End Position wc`UcGO
int nThreadID; //Thread's ID ~-ZquJ-
boolean bDownOver = false; //Downing is over ^YiGvZJ
boolean bStop = false; //Stop identical z3x/Y/X$S
FileAccessI fileAccessI = null; //File Access interface !tJQ75Hwv
'_oWpzpe
%? -E)n[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BJC$KmGk
{ $P rji
this.sURL = sURL; j1D 1tn
this.nStartPos = nStart; @K.{o'
this.nEndPos = nEnd; EIQ`?8KSR
nThreadID = id; UEHJ? }
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +?y ', Ir
} = Lt)15
RC?gozBFJ
>%LZ|*U
public void run() [}:;B$,
{ pZHx
while(nStartPos < nEndPos && !bStop) >J(._K
{ F#Y9 @E
)S"!)\4 b
GWd71ZtFO
try{ 5,dKha
URL url = new URL(sURL); ^m pWQ`R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I8};t b#
httpConnection.setRequestProperty("User-Agent","NetFox"); uIh68UM
String sProperty = "bytes="+nStartPos+"-"; b$FK}D5
httpConnection.setRequestProperty("RANGE",sProperty); mk.1jx?l
Utility.log(sProperty); Hw29V //
v *icoj
pY.R?\
InputStream input = httpConnection.getInputStream(); Kcl~cIh77
//logResponseHead(httpConnection); r c++c,=
Ql>bsr}
4Ys\<\~d
byte[] b = new byte[1024]; (-S\%,hO
int nRead; pNUe|b+P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b:B+x6M
{ vo(riHH
nStartPos += fileAccessI.write(b,0,nRead); p.@kv
//if(nThreadID == 1) -So$f-y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R` g'WaDk
} zH|YVg
(>]frlEU~
xB4}9zN s
Utility.log("Thread " + nThreadID + " is over!"); Wdk]>w 'L
bDownOver = true; Rp^fY_
//nPos = fileAccessI.write (b,0,nRead); V_\9t8
} J(>T&G;
catch(Exception e){e.printStackTrace ();} pSa pF)1>
} KpX1GrIn3
} s#cb wDT
==#mlpi`S[
O}s Mqh
//打印回应的头信息 P*6h$T
public void logResponseHead(HttpURLConnection con) B<$(Nb5<
{ ~#MXhhqB
for(int i=1;;i++) b I"+b\K
{ ^=Dz)95c
String header=con.getHeaderFieldKey(i); LO;7NK
if(header!=null) m+|yk.md
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k%D|17I
Utility.log(header+" : "+con.getHeaderField(header)); je;C}4
else Uc%kyTBm1
break; #nq$^H
} M"\Iw'5$
} {"PIS&]tR
3s\}|LqX#
3QI.|;X
public void splitterStop() 43.Q);4
{ @ /.w%
bStop = true; 8/vGA=
} *Z8qd{.$q
Uee(1
P9 w);jp;
} d%Ls'[Y^_0
c/lT S
T{So2@_&
/* yQcIfl]f
**FileAccess.java #fx>{ vzH
*//文件访问(定位，写) CSwPL>tUV
package NetFox; 1,7
import java.io.*; 3ncN)E/@
;e)`Cv
b|-}?@&7&q
public class FileAccessI implements Serializable{ i&TWIl8
cY^'Cj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b($9gre>mI
RandomAccessFile oSavedFile; QQ,V35Vp[
long nPos; +mPVI
5pU/X.lc
6e>P!bo
public FileAccessI() throws IOException j=dGNi)R
{ x,NV{uG$n
this("",0); M3G ecjR
} mCe"=[
w8D6j%C
:al ,zxs
public FileAccessI(String sName,long nPos) throws IOException Xhs*nt%l
{ ,!O]c8PcU
oSavedFile = new RandomAccessFile(sName,"rw"); od)ssL&E~
this.nPos = nPos; []jbzVwS2
oSavedFile.seek(nPos); F'-,Ksn
} qizQt]l
s:K'I7_#@
?bAv{1dvT=
public synchronized int write(byte[] b,int nStart,int nLen) s<+;5, Q|
{ =O/v]B8"
int n = -1; *C);IdhK%y
try{ Tb:6IC7="
oSavedFile.write(b,nStart,nLen); Pcjrv:0$
n = nLen; 7,s5Gd-
} LAFxeo
catch(IOException e) sd9b9?qiu
{ "$/1.SX;]
e.printStackTrace (); Vx{
} |>RNIJ]
Jot7 L%,TB
6p9 {z42
return n; J4x|Afp
} hSz_e
uPy5<c
_T_6Yl&cf)
} 388vdF
AJ3%Z$JJ;s
6zi 5#23
/* (tyky&$!
**SiteInfoBean.java $V!25jQ
*/ p, T4BO
package NetFox; 34QW^{dgE
I7W`\d)
^T#jBqe
public class SiteInfoBean { W&k@p9
S17;;w0
\Q^grX
private String sSiteURL; //Site's URL *07?U")
private String sFilePath; //Saved File's Path ^/VnRpU
private String sFileName; //Saved File's Name {+]tx46$
private int nSplitter; //Count of Splited Downloading File W^7yh&@lU
jgiS/oW
f@gvDo]Y
public SiteInfoBean() b0/YX@
{//nSplitter的缺省值为5 AB{zkEuK
//default value of nSplitter is 5 +cbF$,M4
this("","","",5); .C.b5x!
} xYZ,.
.4ZOm'ko{
)~Gn7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h@z0 x4_])
{ %LM6=nt
sSiteURL= sURL; PCHKH
sFilePath = sPath; 5$$#d_Gj
sFileName = sName; `8r$b/6
this.nSplitter = nSpiltter; J$PlI
F9Af{*Jw?x
lMH~J8U3
} +$Y*1{hyOo
r\cY R}v
{\vVzy,t7
public String getSSiteURL() (S4HU_,88
{ L[Ot$
return sSiteURL; 3yw$<lm
} CiGXyhh
MsBm0r`a
=av0a!
public void setSSiteURL(String value) ;l1.jQh
{ B;S'l|-?
sSiteURL = value; # E_S..
} rW090Py
Bd7B\zM
^BM !TQ%!
public String getSFilePath() 8;L;R~Q
{ PxQQfI>
return sFilePath; ,"KfZf;?
} '9=b@SaAj
|N^"?bSt
Qwt0~9n(
public void setSFilePath(String value) ZJenwo
{ g?xD*3<
sFilePath = value; 4U_+NC>b
} 73]8NVm
F,A+O+
g$jTP#%b
public String getSFileName() yXoNfsv
{ FZW`ADq]
return sFileName; =36fS/Gb
} K a& 2>F
PO8Z2"WI
Z#B}#*<C
public void setSFileName(String value) {%CW!Rc
{ |d&C<O;f
sFileName = value; ,vO\n^
} 7#d:TXS
wJ pb$;
/a<UKh:A[
public int getNSplitter() U<Tv<7`
{ [*Ai@:F
return nSplitter; ?AD-n6
} nGe4IY\-w
(# mvDz
4I$Y"|_e
public void setNSplitter(int nCount) ;[UI]?A%
{ e[?,'Mp9
nSplitter = nCount; :V5 Co!/+
} BWQ`8
} SMIDW}U2S
m[^)Q9o}
.d}yQ#5z
/* 4sntSlz)~k
**Utility.java 7Mq{Py1
*/ Il9xNVos#
package NetFox; +uSp3gE"
CQNMCYjg(R
<tBT?#C9+
public class Utility { 9 " t;6
_@y uaMoW=
||Owdw|{
public Utility() X'<RqvDc5
{ VBQAkl?(}4
%qz-b.
;y. ;U#O
} \Cu=Le^
k(pJVez
//线程睡眠 U3z23LgA
public static void sleep(int nSecond) YJMs9X~3
{ l"A/6r!Dp
try{ Exqz$'(W9
Thread.sleep(nSecond); 7%EIn9P
} ZzNHEV
catch(Exception e) qqe"hruFJ
{ .B-b51Uz
e.printStackTrace (); Q-V8=.
} _AFje
} x?V^l*
t6\H
//日志 %hN>o)
public static void log(String sMsg) P7b"(G%
{ g%"SAeG<K
System.err.println(sMsg); l[IL~
} |n)4APX\Q
F<4:P=
;M0`8MD
public static void log(int sMsg) JZ`SV}\`
{ f.uuXK
System.err.println(sMsg); krFp q;
} |f @A-d X
} u9|Eos i
C5-u86F
>oWPwXA
/* D{Nd2G
**TestMethod.java n]Yz<#
*/ l"E{ ?4
package NetFox; }dzVwP=
)K@D4sl
v5L+B`~
public class TestMethod { &! h~UZ
)L6 it
..E_M$}
public TestMethod() 9ybR+dGm+
{ ///xx/weblogic60b2_win.exe Z(c SM
try{ PdVx&BL*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?i0+h7=6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J.:
SiteFileFetch fileFetch = new SiteFileFetch(bean); lqv}~MC
fileFetch.start(); Q2Ey RFT
} ?OF$J|h
catch(Exception e){e.printStackTrace ();} QxLrpM"O
Yb5@W/'
)cRHt:
} :FC)+OmJ
hNZ_= <D!
53:u6bb;
public static void main(String[] args) N*|EfI|X
{ Z0zEX?2mb
new TestMethod(); qjkWCLOd
} }NwmZw>_
} )e PQxx
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