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)); x^CS"v7
} Wl4%GB
for(int i=0;i<nEndPos.length-1;i++) ?ubro0F:
{ 5-M-X#(
nEndPos = nStartPos[i+1]; AwN!;t_0+N
} ^@]3R QB
nEndPos[nEndPos.length-1] = nFileLength; `mqMLo*
} \NC3'G:Ii
} Mihg:
_cwpA#x`}
GthYzd:'hJ
//启动子线程 8>V5dEbx'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ts9uL5i
for(int i=0;i<nStartPos.length;i++) I:.s_8mH}
{ M3AXe]<eC1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Pc9H0\+Xk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]f3>-)$*
nStartPos,nEndPos,i); PW4q~rc=:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ntY]SK%Z
fileSplitterFetch.start(); SX*RP;vHy
} _4f;<FL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W9)&!&<o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9FX-1,Jx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H.0K?N&\?>
nEndPos = " + nFileLength); "5 A!jq
// fileSplitterFetch[nPos.length-1].start(); r :dTz
/<3UQLMa
1&2>LE/P
//等待子线程结束 fR|A(u#9
//int count = 0; T;#FEzBz
//是否结束while循环 Wjc'*QCPl
boolean breakWhile = false; 3oqHGA:}
{b{s<@?
54/=G(F
while(!bStop) (w{j6).3Dj
{ r/1(]#kOX
write_nPos(); [ 3HfQ
Utility.sleep(500); ctUp=po
breakWhile = true; 8_F1AU? u
<QvOs@i*
@8 6f
for(int i=0;i<nStartPos.length;i++) OKV8zO
{ 3sk9`=[{$
if(!fileSplitterFetch.bDownOver) j#6.Gq
{ n*$ g]G$
breakWhile = false; e;jdqF~v!
break; 'VbiVLWD
} ME dWLFf
} UI#h&j5pW
if(breakWhile) /E>e"tvss
break; [!z,lY>
u4j5w
XilS!,
//count++; ix$bRdl
//if(count>4) _j3fAr(V
// siteStop(); |{8Pb3#U
} 626r^c=
"]dI1 g_
AR=]=8
System.err.println("文件下载结束！"); kP"9&R`E
} ceV}WN19l
catch(Exception e){e.printStackTrace ();} 8_8l.!~
} =Uh$&m
xA/D'
RpF&\x>
//获得文件长度 hQi2U
public long getFileSize() KSvE~h[#+
{ 9iq_rd]
int nFileLength = -1; o@Oqm>]SS
try{ nlYNN/@"
URL url = new URL(siteInfoBean.getSSiteURL()); OCUr{Nh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ..qCPlK;
httpConnection.setRequestProperty("User-Agent","NetFox"); YMgNzu
G?ZXWu.
weQ_*<5%
int responseCode=httpConnection.getResponseCode(); 8RX&k
if(responseCode>=400) yw!{MO
{ 2?5>o!C
processErrorCode(responseCode); Qd-A.{[h
return -2; //-2 represent access is error $k?>DP4
} dscgj5b1~
P%6~&woF
[~^0gAlQC
String sHeader; <!+Az,-
T|p"0b A
.h[:xYm
for(int i=1;;i++) ZEQEx]Y
{ s>en
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H.c7Nle
//Utility.log(in.readLine()); /B3iC#?
sHeader=httpConnection.getHeaderFieldKey(i); G"6 !{4g
if(sHeader!=null) O}P`P'Y|'
{ *fdTpXa
if(sHeader.equals("Content-Length")) KP"+e:a%
{ Rv=YFo[B
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Vj-h;rB0z
break; Th%zn2R B
} <[phnU^ 8
} yuVs YV@"
else y(&Ac[foS}
break; 6mE\OS-I
} >Q/Dk7#
} VQs5"K"
catch(IOException e){e.printStackTrace ();} [e q&C_|D
catch(Exception e){e.printStackTrace ();} :U\tv[
,bd_:
5bIw?%dk(
Utility.log(nFileLength); SKtrtm
OVJ0}5P*
~dSr5LUD
return nFileLength; lk!@?
} s.#`&Sd>
z{6Z 11|
yX5\gO6G
//保存下载信息（文件指针位置） FlQGgVN
private void write_nPos() @c#(.=
{ >usL*b0%
try{ *I+Q~4
output = new DataOutputStream(new FileOutputStream(tmpFile)); b'g )
output.writeInt(nStartPos.length); ,I9bNO,%JK
for(int i=0;i<nStartPos.length;i++) BWNi [^]
{ >eaaaq9B-
// output.writeLong(nPos); so; ]&
output.writeLong(fileSplitterFetch.nStartPos); G5!^*jf
output.writeLong(fileSplitterFetch.nEndPos); \^LFkp
} <$YlH@;)`a
output.close(); vIvIfE
} "N;EL0=
catch(IOException e){e.printStackTrace ();} =*Lfl'sr_
catch(Exception e){e.printStackTrace ();} 6LZCgdS{
} H+#FSdy#
t7pFW^&
&[9709 (=
//读取保存的下载信息（文件指针位置） r^ XVB`v
private void read_nPos() jCY%|
{ x38QD;MT
try{ gIfh3D=yX
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uO**E-`
int nCount = input.readInt(); DH=hH&[e(d
nStartPos = new long[nCount]; FwK]$4*
nEndPos = new long[nCount]; [ )F<V!
for(int i=0;i<nStartPos.length;i++) N#]ypl
{ f^e)O$N9]
nStartPos = input.readLong(); SJLis"8
nEndPos = input.readLong(); 7=uj2.J6
} JT?h1v<H]
input.close(); WAqINLdX
} [Pp'Ye~K@c
catch(IOException e){e.printStackTrace ();} J4'eI[73
catch(Exception e){e.printStackTrace ();} y7{?Ip4[
} yauvXosX
LD?sh"?b
@iiT<
private void processErrorCode(int nErrorCode) _aphkeqd
{ xk5]^yDp
System.err.println("Error Code : " + nErrorCode); #Y!a6h+
} VUc%4U{Cti
("@!>|H
Y2TtY;
//停止文件下载 ,6/V"kqIP
public void siteStop() B?QIN]
{ s.rm7r@#
bStop = true; b>W%t
for(int i=0;i<nStartPos.length;i++) s"|Pdc4
fileSplitterFetch.splitterStop(); V#HuIgf-
im8CmQ
B~mj 8l4
} :s,Z<^5a)g
} n<,BmVQ
//负责部分文件的抓取 ,uvRi)O>a
**FileSplitterFetch.java zA 3_Lx!
*/ kM6 Qp
package NetFox; NbobliC=
e.>P8C<&
GyIV Hby
import java.io.*; x2EUr,7
import java.net.*; F [M,]?
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"Q0@/bYq
public class FileSplitterFetch extends Thread { EnR}IY&sI
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!if
String sURL; //File URL pmM9,6P4@
long nStartPos; //File Snippet Start Position !1k_PY5)
long nEndPos; //File Snippet End Position SBpL6~NW
int nThreadID; //Thread's ID \zY!qpX<
boolean bDownOver = false; //Downing is over w xH7?tsf
boolean bStop = false; //Stop identical 45e~6",
FileAccessI fileAccessI = null; //File Access interface 7v kL1IA
LLo;\WGZ
_#niyW+?~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ba,`TJ%y
{ eRYK3W
this.sURL = sURL; ok[i<zl;'
this.nStartPos = nStart; ixFi{_
this.nEndPos = nEnd; .8R@2c`}Cs
nThreadID = id; "g|#B4'e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NUZl`fu1Z4
} 6<]lW
2iOV/=+
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public void run() 3Ul*QN{6
{ S!UaH>Rh
while(nStartPos < nEndPos && !bStop) 3<!7>]A
{ M7T5 ~/4
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'V{W-W<
try{ QY/w
URL url = new URL(sURL); zdYjF|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r" y.KD^
httpConnection.setRequestProperty("User-Agent","NetFox"); 2:kH[#
String sProperty = "bytes="+nStartPos+"-"; Ie_wHcM<
httpConnection.setRequestProperty("RANGE",sProperty); +R&gqja
Utility.log(sProperty); paK2xX8E
*T/']t
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InputStream input = httpConnection.getInputStream(); X, n:,'
//logResponseHead(httpConnection); 6'/ #+,d'
_U(
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byte[] b = new byte[1024]; [6fQ7uFMM8
int nRead; =euni}7a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +rd+0 `}C
{ V&5wRz+`W
nStartPos += fileAccessI.write(b,0,nRead); = [E
//if(nThreadID == 1) oxs#866x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ? k/`
} @5FQX
A&VG~r$
KPF1cJ2N
Utility.log("Thread " + nThreadID + " is over!"); k:;r2f
bDownOver = true; \dVOwr
//nPos = fileAccessI.write (b,0,nRead); v+XJ*N[W
} (HVGlw'`
catch(Exception e){e.printStackTrace ();} X8|,
} DVA:Cmh\
} ueudRb
;I}fBZ3
$i&zex{\
//打印回应的头信息 uFE)17E
public void logResponseHead(HttpURLConnection con) z_HdISy0
{ 3w=J'(RU
for(int i=1;;i++) Vksuu@cch
{ 5+vaE 2v
String header=con.getHeaderFieldKey(i); _/|\aqF.
if(header!=null) aUp g u"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]9CFIh
Utility.log(header+" : "+con.getHeaderField(header)); ^!d3=}:0
else vN:Ng
break; >6T8^Nt
} )GpK@R]{
} d=(mw_-?
LoV<:|GTI
jp,4h4C^)
public void splitterStop() K0~rN.C!0
{ ?4,T}@P
bStop = true; 1?}T=)3+$
} DQ3<$0
dN q$}
h{Y",7]!
} N7"W{"3D
h`q1
s;e\ pt
/* 3`g^
**FileAccess.java b}`TLn
*//文件访问(定位，写) [JiH\+XLPs
package NetFox; <I?Zk80
import java.io.*; -RwE%cr
fC`&g~yK'
I9Xuok!0>=
public class FileAccessI implements Serializable{ sC'`~}C
lxx2H1([
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RZLq]8pM
RandomAccessFile oSavedFile; FrS]|=LJhX
long nPos; Ui~>SN>s
1}x%%RD_
K?;DMUSY\
public FileAccessI() throws IOException afVT~Sf{
{ 6x`t{g]f,
this("",0); @ Y+oiB~Y
} -w2/w@&
J1k>07}|
K-v#.e4
public FileAccessI(String sName,long nPos) throws IOException B\~}3!j
{ /uflpV|
oSavedFile = new RandomAccessFile(sName,"rw"); X?O[r3<
this.nPos = nPos; K;?+8(H
oSavedFile.seek(nPos); V[LglPt
} VA%J\T|G2\
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3]Ct6
public synchronized int write(byte[] b,int nStart,int nLen) (PLUFT
{ ?<!|
int n = -1; oH@78D0A
try{ |yCMt:Hk
oSavedFile.write(b,nStart,nLen); kiEa<-]
n = nLen; w)f#V s
} :#Wd~~d
catch(IOException e) )=+|i3]U
{ 5pX6t
e.printStackTrace (); 6nn*]|7
} /~1+i'7V.,
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4#D,?eA7
return n; Mx}gN:Wt
} 5P2K5,o|n~
&>O+}>lr9
\bXa&Lq
} =;L|gtH"
4W75T2q#
2?C)&
/* 97Vtn4N3
**SiteInfoBean.java /vt3>d%B;
*/ :gv"M8AP
package NetFox; F59 TZI
$4\j]RE!
*. t^MP
public class SiteInfoBean { NEs:},)o
xT8?&Bx
iZmcI;?u
private String sSiteURL; //Site's URL =pNY eR_[
private String sFilePath; //Saved File's Path Xw1*(ffk
private String sFileName; //Saved File's Name *~`(RV
private int nSplitter; //Count of Splited Downloading File h[ ZN+M
kJU2C=m@e2
" bG2:
public SiteInfoBean() PT ~D",k
{//nSplitter的缺省值为5 7GGUV
//default value of nSplitter is 5 4+n\k
this("","","",5); k6^Z~5 Sy
} btB%[]
9c],<;{'
637: oT_`O
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ceA9){
{ }V>T M{
sSiteURL= sURL; Om&Dw|xG8
sFilePath = sPath; ~DWl s.
sFileName = sName; Ri'n
this.nSplitter = nSpiltter; >_} I.\X
}H2R3icE
qs6aB0ln
} iZ%yd-
9WHddDA
hTkyz la
public String getSSiteURL() jPeYmv]
{ <@}9Bid!o
return sSiteURL; al0L&z\
} XW9!p.*.U
_F{C\}
~&O%N
public void setSSiteURL(String value) reVgqYp{{-
{ PF2nLb2-
sSiteURL = value; G$PE}%X
} k)u[0}
=Qq+4F)MD
Xj*Wu_
public String getSFilePath() hZ3bVi)L\
{ 5;?yCWc
return sFilePath; 1M-pr 8:6s
} ,Q B<7a+I
G3]4A&h9v~
E7hhew
public void setSFilePath(String value) zDp2g)
{ Z)!C'cb
sFilePath = value; J4utIGF
} 4Hg9N}
^8tEach
)"LJ hLg
public String getSFileName() @x1-! ~z#
{ jpOp.
return sFileName; ?"FbsMk.d
} l%ZhA=TKQ
l, wp4Ll
wBzC5T%,
public void setSFileName(String value) ToQ"Iy?
{ Q\)F;:|
sFileName = value; ,Q,^3*HX9}
} .pq%?&
51u0]Qx;fm
'S~5"6r
public int getNSplitter() S'14hk<
{ m*;ERK
return nSplitter; =xrv~
} f)!Z~t &
z~Q)/d,Ac
*A< 5*Db:F
public void setNSplitter(int nCount) r>\bW)e
{ '|4!5)/K
nSplitter = nCount; 2tLJU Z1
} eQ"E
} hcc/=_hA
-&;TA0~;
1}37Q&2
/* M;NX:mX9
**Utility.java 6RM/GM
*/ Ie^l~Gb
package NetFox; 9kojLqCT
7KPwQ?SjT
$N\Ja*g
public class Utility { ]?)TdJ`
<Qq*p
C>~TI,5a3
public Utility() />Nt[o[r
{ xpI wrJO
R4@6G&2d>
^(<f/C)i
} @KA4N`
V:27)]q
//线程睡眠 ]~%6JJN7
public static void sleep(int nSecond) jtc~DL
{ K>9 ()XT)
try{ fatf*}eln
Thread.sleep(nSecond); >MK98(F
} 9Ee'Cm
catch(Exception e) sr}E+qf
{ i&k7-<
e.printStackTrace (); 6Iw\c
} TKjFp%
} ~4"dweu?
qVPeB,kIz
//日志 rbQR,Nf2x
public static void log(String sMsg) <1pEwI~
{ }i2V.tVB-
System.err.println(sMsg); Ha ]YJ}
} 5?L<N:;J_
KU;9}!#
d1kJRJ
public static void log(int sMsg) iCyfOh
{ 0g\(+Qg^
System.err.println(sMsg); [r-p]"R
} 1sCR4L:+
} <ih[TtZ
T)CP2U
/@Zrq#o zx
/* v3qA":(w+(
**TestMethod.java b6M
*/ >j`qh:^
package NetFox; s<Fl p
Kg$Mx
`W-Fssu
public class TestMethod { 4fzZ;2sl}
akT6^cP^
>3_Gw4S*H
public TestMethod() .~}1+\~5
{ ///xx/weblogic60b2_win.exe pNIf=lA
try{ y?:.;%!E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X7wKy(g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O~QB!<Q+
SiteFileFetch fileFetch = new SiteFileFetch(bean); C-[1iW'
fileFetch.start(); tl].r|yl
} ;>YzEo
catch(Exception e){e.printStackTrace ();} ,(4K4pN
]:f%l mEy
\L\b$4$d
} 0RK!/:'
LK"69Qx?5q
*4Izy14e
public static void main(String[] args) yZ`wfj$Jj
{ Y<rU#Z#T
new TestMethod(); Uwi7)
} #,.Hr#3nI
} N?>vd*
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