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)); bR8 HGH28
} z2nUul(2
for(int i=0;i<nEndPos.length-1;i++) PxVI{:Uz
{ 6v2RS
nEndPos = nStartPos[i+1]; 3{I=#>;
} #9hXZr/8
nEndPos[nEndPos.length-1] = nFileLength; x [{q&N!"`
} vu'!-K=0
} mLk6!&zN
XAULD]Q
Fb{`a[&
//启动子线程 >upXt?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Aiks>Cyi23
for(int i=0;i<nStartPos.length;i++) hKzBq*cV
{ *CPB5s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sg6w7fp>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), oA3W {
nStartPos,nEndPos,i); k"^t?\Q%vI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .M53, 8X
fileSplitterFetch.start(); lgjoF_D
} o S:vTr+$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hA1gkEM2o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6|9g4@Hy
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?<yq 2`\4O
nEndPos = " + nFileLength); peTO-x^a-
// fileSplitterFetch[nPos.length-1].start(); 0q>NE<L
%X9:R'~sP
fBWJ%W
//等待子线程结束 [;IDTo!<>
//int count = 0; hDD~,/yVxs
//是否结束while循环 mcz(,u}
boolean breakWhile = false; c2\rjK
&t*8oNwSs
n2y/zP>TC
while(!bStop) Z*vpQBbu
{ l`M5'r]l
write_nPos(); d[>N6?JA/
Utility.sleep(500); {Z?$Co^R
breakWhile = true; +.gf]|
UU;-q_H6
f?>-yMR|
for(int i=0;i<nStartPos.length;i++) ;oY(I7
{ s7UhC.>'@
if(!fileSplitterFetch.bDownOver) L`HH);Ozw
{ BudWbZ5>Ep
breakWhile = false; we H@S
break; T)Zt'M
} mSw?2ba
} 1W}nYU
if(breakWhile) kh>SrW]B%
break; '!yS72{$2
g@k#J"Q'[
q(jkit~`A
//count++; vU8FHVytV
//if(count>4) [N+ m5{tT
// siteStop(); 6L:trLuQ
} <9d-Hz
,yM}]pwlB
IB#iJ#,
System.err.println("文件下载结束！"); bU:}ZO^S
} VT5cxB<
catch(Exception e){e.printStackTrace ();} <>T&ab@dE(
} =;k+g?.@I
dIk8TJ
fOK+DT~
//获得文件长度 StdS$XW
public long getFileSize() O7'<I|aD
{ A'~%_}
int nFileLength = -1; MR?*GI's
try{ { /F rs*AF
URL url = new URL(siteInfoBean.getSSiteURL()); Mf;|z0UX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Uaus>Frx.T
httpConnection.setRequestProperty("User-Agent","NetFox"); #4P3xa
U=&^H!LVY
{XDY:`vZ}
int responseCode=httpConnection.getResponseCode(); Uxk[O
if(responseCode>=400) {;Y 89&*R
{ ==h|+NFa
processErrorCode(responseCode); :~ZqB\>i
return -2; //-2 represent access is error .0Iun+nUD
} QX/X {h6
S/nj5Lh
;LQ# *NjL\
String sHeader; RVgPH<1X@e
PkPDVv
(<bm4MPf
for(int i=1;;i++) d%#!nq{vd
{ B.}_],
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bVa+kYE
//Utility.log(in.readLine()); c%AFo]H
sHeader=httpConnection.getHeaderFieldKey(i); t g KG&
if(sHeader!=null) !cEbzb
{ [5?4c'Ev
if(sHeader.equals("Content-Length")) (xZr ]v ]U
{ tb:,Uf>E
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M('s|>\l
break; ?Y?gzD
} O6m.t%*
} ~7lTqY\
else yqC Q24
break; e-CNQnO~
} X$7Oo^1;
} ,67"C2Y
catch(IOException e){e.printStackTrace ();} A9\]3 LY
catch(Exception e){e.printStackTrace ();} T3USNc51
W_[|X}lWP
ibd$%;bX3
Utility.log(nFileLength); JmU<y
g.B%#bfg
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return nFileLength; X q}Ucpj
} mF[o*N*
lZ|L2Yg3uB
u*t,i`
//保存下载信息（文件指针位置） NJ;"jQ-
private void write_nPos() 8 uDerJ!
{ fm(mO%
try{ ]{f^;y8
output = new DataOutputStream(new FileOutputStream(tmpFile)); doP$N3Zm
output.writeInt(nStartPos.length); v! 7s M
for(int i=0;i<nStartPos.length;i++) _GVE^yW~z
{ ?M*7@t@
// output.writeLong(nPos); gM4Pj[W
output.writeLong(fileSplitterFetch.nStartPos); yfmp$GO:
output.writeLong(fileSplitterFetch.nEndPos); IDy_L;'`*
} >5)<Uv$
output.close(); 0HGlf
} [8>z#*B
catch(IOException e){e.printStackTrace ();} BdN8 ^W
catch(Exception e){e.printStackTrace ();} LHs-&
} ,Bisu:v6FW
aWyUu/g<A`
$4Z+F#mx
//读取保存的下载信息（文件指针位置） Ye9Y^+-
private void read_nPos() x(L(l=^"
{ /b{o3, #.M
try{ &4,WG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |u@+`4o
int nCount = input.readInt(); rRB~=J"
nStartPos = new long[nCount]; ""co6qo#>
nEndPos = new long[nCount]; sX+`wc
for(int i=0;i<nStartPos.length;i++) J,f/fPaf7
{ AY#wVy
nStartPos = input.readLong(); t)YUPDQ@J
nEndPos = input.readLong(); 6X/wdk
} qE )Y}oN
input.close(); f|OI`
} Vclr)}5
catch(IOException e){e.printStackTrace ();} Z&_y0W=t
catch(Exception e){e.printStackTrace ();} PK_s#uC
} !c%
t/}L36@+
Q"40#RFA
private void processErrorCode(int nErrorCode) O~V1Ywfq7^
{ qu_)`wB
System.err.println("Error Code : " + nErrorCode); u*2fP]n
} kw*)/$5]
pet~[e%!
8{dEpV*
//停止文件下载 PgMbMH
public void siteStop() z~,mRgc$B
{ |6aJwe+*
bStop = true; 3UdU"d[75
for(int i=0;i<nStartPos.length;i++) v:E;^$6Vn
fileSplitterFetch.splitterStop(); iOXZ]Xj5
i[\w%(83Fi
r'/\HWNP
} e@E17l-
} dL-i)F
//负责部分文件的抓取 Vtr3G.P^
**FileSplitterFetch.java Ly;I,)w
*/ tJNIr5o
package NetFox; zh\$t]d<I
4o<*PPA1
w5`#q&?
import java.io.*; CEuWw:)
import java.net.*; sYJL-2JX
hq=,Z1J
#ly@;!M
public class FileSplitterFetch extends Thread { zJ+3g!
w/W7N
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String sURL; //File URL )0^>#k
long nStartPos; //File Snippet Start Position i31<].|kA*
long nEndPos; //File Snippet End Position Ve}[XqdS^p
int nThreadID; //Thread's ID gxwo4.,
boolean bDownOver = false; //Downing is over >H>gH2qp
boolean bStop = false; //Stop identical q/NY72tj0
FileAccessI fileAccessI = null; //File Access interface j(iuz^I
~:4~2d|
>{C\H.N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t6+YXjXK
{ `0{ S3v
this.sURL = sURL; 5,1{Tv`
this.nStartPos = nStart; WK0C
this.nEndPos = nEnd; t V03+&jF
nThreadID = id; qTT,U9]:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Tk*w3c"$
} WF2NG;f=
rAb&I"\ZY
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public void run() Ha%F"V*
{ d H? ScXM=
while(nStartPos < nEndPos && !bStop) .Pe9_ZH$W
{ 7\ypW$Ot
](#&.q%5!
j(eFoZz,
try{ T-gk<V
URL url = new URL(sURL); g JjN<&,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); er2cQS7R
httpConnection.setRequestProperty("User-Agent","NetFox"); x&Cp> +i
String sProperty = "bytes="+nStartPos+"-"; pXu/(&?
httpConnection.setRequestProperty("RANGE",sProperty); 2#vv$YD
Utility.log(sProperty); =wG+Ao
Zp&@h-%YoD
9XLFHV("
InputStream input = httpConnection.getInputStream(); !lTda<;]
//logResponseHead(httpConnection); ('C7=u&F
#]E(N~
fKHE;A*>%
byte[] b = new byte[1024]; GaekFbW)
int nRead; y<- _(^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uLQ
{ cK@jmGj+
nStartPos += fileAccessI.write(b,0,nRead); "B{ECM;
//if(nThreadID == 1) 0:=ZkEEeU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Wh( |+rJ?Z
} x[Im%k
9MY7a=5E~
\K iwUz
Utility.log("Thread " + nThreadID + " is over!"); H={&3poBz
bDownOver = true; [8XLK4e
//nPos = fileAccessI.write (b,0,nRead); 8z2Rry w
} CSTI?A"P
catch(Exception e){e.printStackTrace ();} g5Z#xszj+
} !TKkec8$
} p`F9Amb
*|% ^0#$c
B=Ym x2A9]
//打印回应的头信息 . ]@=es
public void logResponseHead(HttpURLConnection con) 2HD]?:Fk7
{ y "w|g~x]c
for(int i=1;;i++) pZ(Fx&fy
{ +nL+N
String header=con.getHeaderFieldKey(i); D)@XoM(
if(header!=null) k5`OH8G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $HJTj29/
Utility.log(header+" : "+con.getHeaderField(header)); {Qv>q$Q
else ;eL9{eF
break; "*z_O
} |Ic`,>XM
} | ?yo 3
&a,OfSz
52_#
public void splitterStop() F {+`uG
{ r?/A?DMe
bStop = true; TUIk$U?/I
} 1f'Hif*r_X
'heJ"k?
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} ^|!I+
c{+AJ8
j*v40mXl`2
/* ? "/ fPV-
**FileAccess.java Iu@y(wyg
*//文件访问(定位，写) -r7]S
package NetFox; bzN-*3YE=
import java.io.*; A{eLl
+rXF{@ l
!7bw5H
public class FileAccessI implements Serializable{ ~EzaC?fQ
a:,y Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;`YkMS`=W
RandomAccessFile oSavedFile; <A5]]{9 +
long nPos; |RkcDrB~
Q/ms]Du
xNK1h-t
public FileAccessI() throws IOException i_Re*
{ /u%h8!"R
this("",0); &MZ$j46
} nlYR-.
YevyN\,}V!
M:KbD|
public FileAccessI(String sName,long nPos) throws IOException g7V8D
{ l_'[27
oSavedFile = new RandomAccessFile(sName,"rw"); )d\j I
this.nPos = nPos; (>4aibA'P
oSavedFile.seek(nPos); :~Q!SL N
} }R[#?ty;]
uMb>xxf
WEg6Kz
public synchronized int write(byte[] b,int nStart,int nLen) m([(:.X/IX
{ oX@ya3!Pz
int n = -1; =J-5.0Q\_\
try{ kum#^^4G|
oSavedFile.write(b,nStart,nLen); kd`0E-QU
n = nLen; [H<bh%
} j$UV/tp5T
catch(IOException e) M->*{D@a
{ VV4Gjc
e.printStackTrace (); %3q0(Xl
} /MMd`VrC2
Migd(uw'
u's`*T@.
return n; kE8>dmH23
} Wz4&7KYY
zya5Jb:Sg
v~3B:k:?l
} 3f" %G\
vK7\JZ>
UJfT!==U
/* >d"3<S ;b
**SiteInfoBean.java n\Fp[9+Z\
*/ &AVpLf:?
package NetFox; {t"+ 3zy'
Oa;X+
FLg*R/
public class SiteInfoBean { )#|<w9uec
4(}J.-B
D(p\0V
private String sSiteURL; //Site's URL Jd\apBIf
private String sFilePath; //Saved File's Path 9)xUA;Qw?z
private String sFileName; //Saved File's Name )VL96did
private int nSplitter; //Count of Splited Downloading File :@W.K5
NNhL*C[_7
Xs&TJ8a
public SiteInfoBean() uw\2qU3gk
{//nSplitter的缺省值为5 V.ht, ~l
//default value of nSplitter is 5 @`tXKP$so
this("","","",5); ES~^M840f
} 21s4MagC
UYk>'\%H0
`l2O?U-@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ? J}r
{ !USd9
sSiteURL= sURL; 8}H1_y-g[
sFilePath = sPath; ~\x:<)
sFileName = sName; &l$Q^g
this.nSplitter = nSpiltter; 1O].v&{
kGpa\c g1
-jgysBw+Xb
} +3s%E{
M(#m0xB
u2oKH{/z
public String getSSiteURL() ikWtC]y
{ DeR='7n
return sSiteURL; Z_\C*^
} 9/+Nj/
:o:e,WKxb
Rqwzh@}
public void setSSiteURL(String value) ,q(&)L$S
{ =@TQ>Qw%b
sSiteURL = value; #r PP*
} 7+x? "4
^pM+A6 XY
+<,gB $j
public String getSFilePath() NmMIQ@K
{ ;8!Z5H
return sFilePath; dU\%Cq-G)
} *[=bR>
"V{yi!D{<
UhIDRR
public void setSFilePath(String value) K)TrZ 2
{ ~|wbP6</:-
sFilePath = value; #:T-hRu
} hOhS)
Kwc6mlw~M
VqL.iZ-
public String getSFileName() cA6lge<{~
{ XeBP`\>Ve
return sFileName; .>z][2oz
} eIl]oC7*
uKgZ$-'
XZw6Xtn
public void setSFileName(String value) JdZ+Hp3.
{ P0`Mdk371
sFileName = value; Xl@cHO=i
} AoA!q>
WyP W*
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public int getNSplitter() NEa>\K<\
{ s;UH]
return nSplitter; PRNoqi3sY
} ~ %B<
v]B L[/4
@ 49nJi
public void setNSplitter(int nCount) VLBE'3Qg1
{ 5k|9gICyd*
nSplitter = nCount; eT2*W$
} t>8XTqqi
} Scv#zuv_
k+1|I)z
"`6n6r42
/* (H+'X}1
**Utility.java Zo>]rKeV
*/ <AJ97MLcc
package NetFox; tGB@$UmfU
HHqwq.zIy
Gycm,Cy
public class Utility { ko5V9Drc
[]s^
_G1gtu]
public Utility() bI|2@HV2
{ PqM1aoyX
)}9rwZ
xC C:BO`pw
} u4Em%:Xj
<3,<\ub
//线程睡眠 b,8{ X<
public static void sleep(int nSecond) qC'{;ko
{ _HhbIU
try{ "vtCTl~t
Thread.sleep(nSecond); .$@R{>%U
} 86 W0rS[5
catch(Exception e) Ecs,$\
{ kA7mLrON
e.printStackTrace (); IKie1!ZU{"
} cyJG8f
} bTQNb!&
Ytgj|@jsp
//日志 aZbw]0q@o
public static void log(String sMsg) [ Bl c^C{f
{ }B~If}7
System.err.println(sMsg); imiR/V>N
} 7 I>G{
epgPT'^
sUPz/Z.h
public static void log(int sMsg) )& u5IA(
{ -(K9s!C!.
System.err.println(sMsg); ~)(\6^&=|
} vOg#Dqn-
} Hr$QLtr
"Ky; a?Y
h,"4SSL
/* ^eoLAL
**TestMethod.java tnLAJ+-M
*/ F`9]=T0
package NetFox; U!Ek'
H:"maS\I
ul*Qt}
public class TestMethod { )Pv9_XKJ
2h%z ("3/
P (S>=,Y&
public TestMethod() YtO|D
{ ///xx/weblogic60b2_win.exe H*9~yT'Q
try{ r[K5w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~H!S,"n^,P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "+unS)M;Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;t+ub8
fileFetch.start(); \(%Y%?dy
} '? jlH0;
catch(Exception e){e.printStackTrace ();} jMpD+Mb
0>zbCubPH
VsA'de!V4[
} U#U]Pt
SB)5@ nmS
^i:B+ rl
public static void main(String[] args) qpXWi &g
{ (dv]=5""
new TestMethod(); a5w:u5
} 'MY/*k7:
} H8"@iE,
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