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)); NmXTk+,L#
} oyY,uB.|
for(int i=0;i<nEndPos.length-1;i++) cgAcAcmY
{ }P#gXG
nEndPos = nStartPos[i+1]; DO; 2)ZQ%
} 0>Nq$/!
nEndPos[nEndPos.length-1] = nFileLength; iddT.
} $cedO']
} xR3A4m
"a7d`l:
`MS=/xE
//启动子线程 HF:PF"|3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Qw+">
for(int i=0;i<nStartPos.length;i++) J.(_c' r
{ 4)z](e$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q2uE_w`B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V2X(f6v
nStartPos,nEndPos,i); 7y3; F7V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *!kg@ _0K
fileSplitterFetch.start(); sa($3`d
} *bK@A2`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,#6\:i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /zM7G?y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0v?,:]A0E
nEndPos = " + nFileLength); ,v+SD\7|
// fileSplitterFetch[nPos.length-1].start(); gf@Dy6<
Z^3Risi
[z9i v~
//等待子线程结束 <Lt$qV-#
//int count = 0; W\ckt]'
//是否结束while循环 iD~s,
boolean breakWhile = false; IYFA>*Es
FdD'Hp+
@2<J_Ja
while(!bStop) n1|%xQBU@
{ kW9STN
write_nPos(); bYfcn]N
Utility.sleep(500); A [JV*Dt
breakWhile = true; qA42f83
xN]bRr
TV}SKvu
for(int i=0;i<nStartPos.length;i++) bhRpYP%x
{ [F$3mzx
if(!fileSplitterFetch.bDownOver) -JK+{<
{ rm7UFMCR6i
breakWhile = false; ORO~(%-(e
break; 4{_5z7ody
} RXDk8)^
} w,&RHQB
if(breakWhile) N'StT$(
break; TBzM~y
^AN9m]P
_\6-]
//count++; R;%iu0
//if(count>4) sq%f%?(V
// siteStop(); f]EHDcC3X
} sQkP@Y
!Kis,e
DbDpdC;
System.err.println("文件下载结束！"); /i<g>*82
} [3s~Z8 pP
catch(Exception e){e.printStackTrace ();} &1&*(oi]X
} Wd7*sa3T
>HDK<1>
1/ a,7Hl
//获得文件长度 Ez)Go6Q
public long getFileSize() .IqS}Rh
{ A U](pXK;
int nFileLength = -1; B?]^}r
try{ GZ1>]HB>r^
URL url = new URL(siteInfoBean.getSSiteURL()); n1QO/1} :
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b#b#r
httpConnection.setRequestProperty("User-Agent","NetFox"); fu`oDi
!@Ox%vK
T|u)5ww%
int responseCode=httpConnection.getResponseCode(); sG3%~
if(responseCode>=400) ms?h/*E<H
{ ]k hY8it
processErrorCode(responseCode); }*%%GPJ
return -2; //-2 represent access is error 09Fr1PL
} 7-^d4P+|g
Ne=D$o
w$pv
String sHeader; xN5}y3
j/sZ:Q
iZ{D_uxq
for(int i=1;;i++) _jtBU
{ milU,!7J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z:w7e0
//Utility.log(in.readLine()); "Kqe4$
sHeader=httpConnection.getHeaderFieldKey(i); NTV0DkX
if(sHeader!=null) %bAv.'C
{ \t}!Dr+yN
if(sHeader.equals("Content-Length")) +iXA|L9=
{ <_D+'[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j,~h:MT
break; %l>^q`p
} D~-Ri`k.
} P63f0F-G
else ZY83,:<
break; *_ "j"{
} pvX\kX3}
} 6,!]x>B
catch(IOException e){e.printStackTrace ();} >Zr`9$i
catch(Exception e){e.printStackTrace ();} ?g!)[p`v
q|S }5
=4?m>v,re
Utility.log(nFileLength); J<'4(}^|
7y:J@fh<
WKN\*N<
return nFileLength; hp)3@&T
} #q%&,;4
c(o8uWn
oM< 9]jK}
//保存下载信息（文件指针位置） IkD\YPL;
private void write_nPos() .7oz
{ [z?<'Tj
try{ BsxQW`>^y
output = new DataOutputStream(new FileOutputStream(tmpFile)); f;QWlh"9
output.writeInt(nStartPos.length); NbSwn}e_
for(int i=0;i<nStartPos.length;i++) =x=#Etj|
{ ~}uTC36C\
// output.writeLong(nPos); 'peFT[1>(
output.writeLong(fileSplitterFetch.nStartPos); 8}4V$b`Z
output.writeLong(fileSplitterFetch.nEndPos); 9]l7j\L
} m#Rll[
output.close(); O4 [[9
} *vht</?J
catch(IOException e){e.printStackTrace ();} sI#K01;"
catch(Exception e){e.printStackTrace ();} cBU>/ zIp
} F$d`Umqs;P
/']Gnt G.
?L'ijzP
//读取保存的下载信息（文件指针位置） 2nk}'HBe
private void read_nPos() 8USF;k
{ euQd
try{ rNdap*.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); QH;1*
int nCount = input.readInt(); ;|66AIwDe
nStartPos = new long[nCount]; 68d(6?OgW
nEndPos = new long[nCount]; \!`*F:7]-
for(int i=0;i<nStartPos.length;i++) gJ:Z7b
{ jytfGE:
nStartPos = input.readLong(); ZfS-W&6Z
nEndPos = input.readLong(); iGM-#{5
} YYN=`ST
input.close(); uYF_sf
} 7n5bI\
catch(IOException e){e.printStackTrace ();} Drc\$<9c@
catch(Exception e){e.printStackTrace ();} iYR8sg[' #
} PbCXcs
AfyEFnY
)0YMi!&j`
private void processErrorCode(int nErrorCode) cSQvP.
{ ji:JLvf]%
System.err.println("Error Code : " + nErrorCode); >{V]q*[/;Q
} m;k' j@:
UfXqcyY(
Za5*HCo
//停止文件下载 o^biO!4,
public void siteStop() $yBU ,lu}
{ u<:RSg
bStop = true; o=7 -&F.
for(int i=0;i<nStartPos.length;i++) nz~3o
fileSplitterFetch.splitterStop(); wYPJji D
:k#Y|(
|s+y]3-_
} 5e6f)[}
} N.l+9L0b
//负责部分文件的抓取 }]'Z~5T
**FileSplitterFetch.java 5F18/:\n
*/ "oz qfh
package NetFox; LY-fp+
vm_+U*%c
N[~RWg
import java.io.*; $<OX\f%
import java.net.*; KQ9~\No]
!X*+Ct^
M| :wC
public class FileSplitterFetch extends Thread { g:7S/L0]
qk<(iVUO
TmxhP nJ~
String sURL; //File URL tt$DWmm
long nStartPos; //File Snippet Start Position |7LhE+E
long nEndPos; //File Snippet End Position ZEYT17g]
int nThreadID; //Thread's ID C4Z}WBS(
boolean bDownOver = false; //Downing is over )v !GiZ"7
boolean bStop = false; //Stop identical )"`(+Ku&c
FileAccessI fileAccessI = null; //File Access interface ?);6]"k:3
.B_LQ;0:
o$)pJ#";F
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0K<y }
{ x1VBO.t=*
this.sURL = sURL; z~\a]MB
this.nStartPos = nStart; hd0d gc
this.nEndPos = nEnd; SVB> 1s9F
nThreadID = id; "%ou'\}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ce7$r*@!
} n;+CV~
+GqK$B(x7
T#KF@8'-
public void run() t.Q}V5t{g
{ }tJRBb
while(nStartPos < nEndPos && !bStop) }-4@EC>
{ s&&8~ )H
u5zL;C3O
g^ .g9"
try{ O=m_P}K
URL url = new URL(sURL); ]z3!hgTj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Bp&7:snGt
httpConnection.setRequestProperty("User-Agent","NetFox"); r{2V`h1/|
String sProperty = "bytes="+nStartPos+"-"; :x88
httpConnection.setRequestProperty("RANGE",sProperty); l Oxz&m
Utility.log(sProperty); E0HXB1"
K ?uHAm
Ad7N'1O
InputStream input = httpConnection.getInputStream(); RBuerap
//logResponseHead(httpConnection); }\ kLh(
|p_\pa1&
p6S{OUiG
byte[] b = new byte[1024]; [l# 8}dy
int nRead; /Q]6"nY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8`g@ )]Iy
{ im,H|u_f4
nStartPos += fileAccessI.write(b,0,nRead); vX?MB
//if(nThreadID == 1) =f~8"j
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vtx3a^
} mv1g2f+
0nOkQVMk>
=#=<%HPT
Utility.log("Thread " + nThreadID + " is over!"); oyw*Z_9~
bDownOver = true; R;d)I^@
//nPos = fileAccessI.write (b,0,nRead); vC#_PI
} Q+<{2oVz
catch(Exception e){e.printStackTrace ();} 4e`GMtp
} <b.O^_zQF
} vD-m FC)
vM3 b\yp
9Gh:s6
//打印回应的头信息 ]9A@iA
public void logResponseHead(HttpURLConnection con) n3z]&J5fr
{ }R&5Ye
for(int i=1;;i++) bT>1S2s
{ ,vcg%~-
String header=con.getHeaderFieldKey(i); {u}d`%_.M
if(header!=null) {)`tN&\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MA`.&MA.
Utility.log(header+" : "+con.getHeaderField(header)); BT*z^ZH
else &"gQrBa
break; F=g+R~F
} 5mqwNAv
} Dve+ #H6N
zk++#rB
/_(q7:<ZF
public void splitterStop() uN;]Fv@Z
{ P->.eo#VG
bStop = true; $n#NUPzG+
} ^]zC~LfG
']&rPvkL
zz m[sX}
} x{_3/4
q)f-z\
w7E7r?)Wl|
/* +tCNJ<S@l$
**FileAccess.java S_ER^Pkg
*//文件访问(定位，写) }K.2
package NetFox; 59MpHkr
import java.io.*; #?_8 *?
V44M=c7E
\- f^C}m
public class FileAccessI implements Serializable{ `JAM]qB"
X/qLg+X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 TgjM@ir
RandomAccessFile oSavedFile; V48o+O
long nPos; PRi1 `%d
Dt~ |)L+
/%{Qf
public FileAccessI() throws IOException "8l&m6`U-
{ b?]Lx.l-
this("",0); eqQ=HT7J
} *=b36M
|aX1PC)o_
WNO!6*+
public FileAccessI(String sName,long nPos) throws IOException zDohp 5,
{ D!WyT`T
oSavedFile = new RandomAccessFile(sName,"rw"); CzfGb4
this.nPos = nPos; |r<#>~*
oSavedFile.seek(nPos); #V-0-n,`
} p0sq{d~
o>jM4sk$
Ad)::9K?J
public synchronized int write(byte[] b,int nStart,int nLen) 6k+4R<
{ ^~DDl$NH
int n = -1; I-L:;~.
try{ y!u=]BE
oSavedFile.write(b,nStart,nLen); | k?r1dj%O
n = nLen; Ftw;T|
} htu(R$GSM
catch(IOException e) J^gElp
{ E(-@F%Q
e.printStackTrace (); "n%0L4J
} kNk$[Yfs
Hw1:zro
y*<x@i+h
return n; k];NTALOG
} )cV*cDL1j
sLze/D_M*
kCHYLv3.
} tl"?AQcBR
yOswqhz
Yaix\*II
/* LK:Jkjp^
**SiteInfoBean.java C )J@`E
*/ 2>*b.$g
package NetFox; |))O3]-
nh]}KFO h
-$sVqR>_
public class SiteInfoBean { :d=:>_[
O48*"Z1
@Yj+u2!
private String sSiteURL; //Site's URL yllEg9L0z
private String sFilePath; //Saved File's Path W|CZA
private String sFileName; //Saved File's Name 6%a:^f]
private int nSplitter; //Count of Splited Downloading File Wy.^1M/n>~
@(W{_mw
>e"vPW*[
public SiteInfoBean() UUR+PfY
{//nSplitter的缺省值为5 u3vM!
//default value of nSplitter is 5 9p4=iXfR
this("","","",5); 7CDp$7v2
} *O'`&J
6olJ7`*
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v}sk %f
{ svvl`|n%
sSiteURL= sURL; M2!2J
sFilePath = sPath; i`^[_
sFileName = sName; YR-Ge
this.nSplitter = nSpiltter; >/.w80<'
#?C.%kD
2y5d
} mX5%6{],
;~-M$a }4
CK9FAuU
public String getSSiteURL() *2>kic aH
{ W9!K~g_
return sSiteURL; {RC&Ub>
} :5[1Iepdn
@! {Y9k2
e+<'=_x {
public void setSSiteURL(String value) .]YTS
{ 7q(A&
sSiteURL = value; a.2Xl}2o5
} 5@_kGoqd
d1';d6.u\
Tfp^h~&u
public String getSFilePath() /m|U2rrqb
{ 7S2"e[-x
return sFilePath; %%sJ+)
} Z=dM7Lj*
B}+li1k
Qs,4PPEg
public void setSFilePath(String value) LYO2L1u)
{ -*$ s ;G#
sFilePath = value; Zo<j"FG
} hQ (84u
gy Ey=@L
Mp?L9
public String getSFileName() GK=b
{ Xp[xO0
return sFileName; :i>If:>g
} hgK 4;R
=Q*x=}NH
s#H_QOE
public void setSFileName(String value) N6HeZB":
{ l[<U UEjZJ
sFileName = value; H/y,}z
} y96HTQ32
\Oxyc}&
d:pGdr& .
public int getNSplitter() s_}`TejK
{ cH6++r
return nSplitter; :-Ml?:0_X
} [@_W-rA
.(99f#2M:
Wv||9[Rd
public void setNSplitter(int nCount) &2bqL!k
{ "7Z-ACyF5
nSplitter = nCount; *x:*Q \|
} ?I$-im
} c2gi3
%j@@J\G!
t:"3MiM=c
/* hp`ZmLq/[
**Utility.java YQcaWd(
*/ &z#`Qa3NI
package NetFox; d ehK#8
Xe&p.v
qKrxln/T
public class Utility { EbG&[v
@H8DGeM
(K_{a+$[
public Utility() @N]]Cf>x
{ Lg~ll$ U
&["e1ki
qw 03]a
} ~F8xXW0
pxn@rN#*
//线程睡眠 2u$rloc$b
public static void sleep(int nSecond) _F5*\tQ
{ >p'{!k
try{ M@o^V(j
Thread.sleep(nSecond); Cu!]-c{
} JT&RaFX
catch(Exception e) _+X-D9j(l
{ _u]%K-_
e.printStackTrace (); CeeAw_*@
} mV^~
} ^HxIy;EQ<z
I1Otu~%d
//日志 yfal'DqKF
public static void log(String sMsg) *E]:VZl
{ +D2I~hC0'
System.err.println(sMsg); #qFY`fVf1
} o7s!ti\G
kD0bdE|
H'JU5nE
public static void log(int sMsg) PW82 Vp.
{ Au6Y]
System.err.println(sMsg); .)SR3?
} f!#+cM
} +w-J;GLSy
a|jZg
oKCv$>Y
/* ":f]egq -
**TestMethod.java S+#|j
*/ |#sOa
package NetFox; (k8}9[3G
+H28F_#
T2 S fBs
public class TestMethod { VFzIBgJ3
I]DD5l}\
g+5c"Yk+u~
public TestMethod() LM+d3|gSV
{ ///xx/weblogic60b2_win.exe NJ]3qH
try{ a9UXg<4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kIX1u<M~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !JyY&D~`
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]jYFrOMy4S
fileFetch.start(); -i1 f ]Bd
} J!2j]?D/e
catch(Exception e){e.printStackTrace ();} :.r_4$F:
I~:gi@OVV
u88wSe<\X
} b\"w/'XX
D$7#&2y
3%hq<
public static void main(String[] args) tU5uL.( O
{ dt^h9I2O
new TestMethod(); fvcS=nRQv
} ?^M,Mt
} *yaS^k\
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