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)); `OfhzOp
} .vu7$~7
for(int i=0;i<nEndPos.length-1;i++) \o>-L\`O
{ kKyU?/aj
nEndPos = nStartPos[i+1]; b"I#\;Ym
} M)bQvjj
nEndPos[nEndPos.length-1] = nFileLength; cgb>Naa<
} h.\I tK{)
} "DW~E\Y
l9.`2d]o
46C%at M0}
//启动子线程 ._}}@V_/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u[GZ~L
for(int i=0;i<nStartPos.length;i++) WcN4ff-
{ Af|h*V4Xu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -<g9) CV5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (p{X.X+
nStartPos,nEndPos,i); )d3 09O
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0+>g/>
fileSplitterFetch.start(); `d_T3^ayu
} T)! }Wvv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dSGdK $XA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #w{`6}p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I{IB>j}8
nEndPos = " + nFileLength); '.|}
// fileSplitterFetch[nPos.length-1].start(); uN%Cc12
vpu#!(N
Ik:G5m<ta
//等待子线程结束 v$}^$8`
//int count = 0; I-#!mFl
//是否结束while循环 u+)!C*ho
boolean breakWhile = false; ?@"@9na
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5{! fa
while(!bStop) r^,_m,s'<
{ b<u\THy#
write_nPos(); L=<xTbY
Utility.sleep(500); Thggas,
breakWhile = true; /uw@o9`~2-
5U?O1}P
QV[&2&&^<<
for(int i=0;i<nStartPos.length;i++) yX&# rI
{ ZX_QnSNZ?
if(!fileSplitterFetch.bDownOver) mIlg=8:
{ ?_]Y8f
breakWhile = false; LK h=jB^bT
break; nDrRK
} iA[T'+.Y
} fG2)r
if(breakWhile) Y9abRrK
break; +R~]5Rxd
}u^bTR?3
:DH@zR
//count++; `gl?y;xC
//if(count>4) !&U75FpN}:
// siteStop(); <$nPGz)}
} ]TrJ*~
30h[&Oc
+k=*AQt^8
System.err.println("文件下载结束！"); 8r(Vz
} lO@-*m$
catch(Exception e){e.printStackTrace ();} Vz mlKVE
} ]yOM
2^XmtT
ev&l=(hY
//获得文件长度 ]D6<6OB
public long getFileSize() kH 9k<{
{ }wf8y
int nFileLength = -1; sX?arI=_U
try{ S1r{2s&
URL url = new URL(siteInfoBean.getSSiteURL()); '&CZ%&(Gw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0hS&4nW
httpConnection.setRequestProperty("User-Agent","NetFox"); N<#J!0w
k7Nx#%xx
4W>DW`{
int responseCode=httpConnection.getResponseCode(); LsR<r1KDJ
if(responseCode>=400) 2[w9#6ly
{ {A}T^q!m]
processErrorCode(responseCode); <(E)M@2
return -2; //-2 represent access is error (s'xO~p
} P0UR{tK
&tOo[U?
9^Xndo]y
String sHeader; RlfI]uCDM
{r&r^!K;
ZPf&4#|
for(int i=1;;i++) <@7j37,R7V
{ CX#d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !d##q)D f?
//Utility.log(in.readLine()); 6UIS4_
sHeader=httpConnection.getHeaderFieldKey(i); ^ iu)vED
if(sHeader!=null) 8z93ETv7`
{ -dMH>e0
if(sHeader.equals("Content-Length")) $;g*s?F*
{ ceg\lE:8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d^'_H>x
break; ygTfQtN
} WDNj7
} fTmJDUv+
else r%: :q^b3
break; Xp;'Wa"@
} 6~ET@"0uK
} i(A`'V8GY
catch(IOException e){e.printStackTrace ();} <,Gjo]z
catch(Exception e){e.printStackTrace ();} [?z;'O}y
['(qeS@5O
d Np%=gIj
Utility.log(nFileLength); hbXmIst
>u%Bn\G
KMT$/I{p,
return nFileLength; uJ"#j X
} UHJro9
ZV Ko$q:F
65B&>`H~
//保存下载信息（文件指针位置） Ds=d~sNu
private void write_nPos() w[2E:Nj
{ 4gZR!J
try{ E2hML
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q8TR@0d
output.writeInt(nStartPos.length); .t^1e
for(int i=0;i<nStartPos.length;i++) qPu?rU{2
{ W&A^.% 2l
// output.writeLong(nPos); +fvVora
output.writeLong(fileSplitterFetch.nStartPos); HmXxM:[4;
output.writeLong(fileSplitterFetch.nEndPos); pDC`Fi
} i{g~u<DH)Q
output.close(); dsEvpa$?
} F, =WfM\
catch(IOException e){e.printStackTrace ();} xqT} 9,
catch(Exception e){e.printStackTrace ();} r 8N<<^
} |$8N*7UD
"+Ks#
Xe}I;sKrB
//读取保存的下载信息（文件指针位置） = CXX.%N
private void read_nPos() gC6Gm':c
{ yFo8x[
try{ a;i}<n7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tm;\m!^X{
int nCount = input.readInt(); TPJuS)TU9
nStartPos = new long[nCount]; p@$92> '
nEndPos = new long[nCount]; mv<cyWp
for(int i=0;i<nStartPos.length;i++) ?zo7.R-Vac
{ c3fd6Je5
nStartPos = input.readLong(); x}C$/7^
nEndPos = input.readLong(); (>Sy,
} LWo)x
input.close(); JpQV7}$
} ^b&hy&ag
catch(IOException e){e.printStackTrace ();} hzV%QDUpe
catch(Exception e){e.printStackTrace ();} Mt4`~`6
} *{fZA;<R
}Ej^"T:H_;
j%!xb><
private void processErrorCode(int nErrorCode) IFSIQ q
{ 7vqE@;:dt
System.err.println("Error Code : " + nErrorCode); yrzyus
} 'mU\X!- 4<
=+e;BYD#!
F0xm%?
//停止文件下载 "t{D5{q|[k
public void siteStop() V" 5rIk
{ 2$Z4 >!
bStop = true; ZB}zT9JaE
for(int i=0;i<nStartPos.length;i++) rp-.\Hl/a
fileSplitterFetch.splitterStop(); 3qfQlqJ&3
7n#Mh-vq
kDKfJp&a
} ]{-ib:f~
} Si;eBPFH
//负责部分文件的抓取 kKQD$g.z6
**FileSplitterFetch.java `C:J{`
*/ )q7!CG'oY
package NetFox; ZYl*-i&~?
QswFISch
!&8B8jHqA
import java.io.*; !;PKx]/&
import java.net.*; 0@!-+}i
=rNI&K_<
S?H qrf7<
public class FileSplitterFetch extends Thread { Yu9(qRK
c"'JMq
$+ \JT/eG9
String sURL; //File URL 4m9]d)
long nStartPos; //File Snippet Start Position ds+0y;vc
long nEndPos; //File Snippet End Position =sXk,I;
int nThreadID; //Thread's ID ]gb?3a}A
boolean bDownOver = false; //Downing is over uQkFFWS
boolean bStop = false; //Stop identical [MM`#!K%
FileAccessI fileAccessI = null; //File Access interface uY)|
j&?@:Zg v
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q-0( Wx9|
{ CwzDkr&QC_
this.sURL = sURL; |A u+^#:;
this.nStartPos = nStart; j|WN!!7
this.nEndPos = nEnd; 2K(zYv54
nThreadID = id; -[lOf
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DTV"~>@
} 5 .bU2C
r/ LgmVRn
/9u12R*<
public void run() \g;-q9g;O
{ A3e83g~L
while(nStartPos < nEndPos && !bStop) XuW>GT/
{ Pu]Pp`SP
XgZ.UT
9&KiG* .
try{ /`B:F5r
URL url = new URL(sURL); y}lqF8s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v+2t;PJd2
httpConnection.setRequestProperty("User-Agent","NetFox"); 7gbu7"Qc
String sProperty = "bytes="+nStartPos+"-"; Pu|3_3^
httpConnection.setRequestProperty("RANGE",sProperty); >^KO5N-:4
Utility.log(sProperty); r7:4|6E
bu r0?q
&qFy$`"
InputStream input = httpConnection.getInputStream(); Z:%~Al:
//logResponseHead(httpConnection); <bOi}
$~.'Tnk)
|rk4,NG.
byte[] b = new byte[1024]; -6>T0-
int nRead; r`CsR0[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OM7EmMa;
{ ~@Eu4ip)F
nStartPos += fileAccessI.write(b,0,nRead); Hk|wO:7Be
//if(nThreadID == 1) Y]{~ogsn$:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |"EQyV
} \ssqIRk
KP]{=~(
2~*.X^dR
Utility.log("Thread " + nThreadID + " is over!"); S_56!
bDownOver = true; (E?X@d iu
//nPos = fileAccessI.write (b,0,nRead); m&8'O\$
} ^NiS7)FX
catch(Exception e){e.printStackTrace ();} niJtgK:H^
} Tf?|*P
} 3It9|Y"6[
&,~Oi(SX5
aRF}FE,u
//打印回应的头信息 G$$y\e$
public void logResponseHead(HttpURLConnection con) 4brKAqg.
{ dJD8c2G
for(int i=1;;i++) 4XXuj
{ loFApBD=$^
String header=con.getHeaderFieldKey(i); sDnXgCcS!
if(header!=null) \$[S=&E
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N1i%b,:3
Utility.log(header+" : "+con.getHeaderField(header)); etWCMR
else iqPMCOPZ
break; zU,Qph ,<
} V0!$k.Wk
} :NPnwX8w
Rz9IjL.Z
;/g Bjp]H
public void splitterStop() wm/=]*jpK
{ h"DxgG
bStop = true; 1x~dsM;q
} a6i%7Om
z8\z`#g!
GY,HEe]2r
} &!5S'J%
Sr?2~R0&
HTU?hbG(
/* ev;R; 0<
**FileAccess.java (^).$g5Hg
*//文件访问(定位，写) e${Cf
package NetFox; ~*Kk+w9H<
import java.io.*; ij+)U`
;XXB^,
of k@.TmO
public class FileAccessI implements Serializable{ R9`37(c9+
' (1`iQ;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iy\ 6e k1
RandomAccessFile oSavedFile; .~t.B!rVSB
long nPos; {gwJ>]z"e
Xe7/
YA[\|I33
public FileAccessI() throws IOException 0<C]9[l
{ &@h(6
this("",0); QlCs,bT
} VuWBWb?0Q
.>Fy ]Cqoh
r0fxEYze&
public FileAccessI(String sName,long nPos) throws IOException yO`HL'SMo
{ 85GU~.
oSavedFile = new RandomAccessFile(sName,"rw"); C=>IJ'G
this.nPos = nPos; [uD G;We=
oSavedFile.seek(nPos); I@/+=
} Ri mz~}+
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Q'qz(G0
public synchronized int write(byte[] b,int nStart,int nLen) =AIeYUh
{ M6o"|\
int n = -1; $vK(Qm
try{ +XP9=U*g
oSavedFile.write(b,nStart,nLen); 2j <Y>Y
n = nLen; n3Q Rn^
} LW '3m5
catch(IOException e) 1ms(03dp
{ oW \k%Vj
e.printStackTrace (); &K.js
} yrVk$k#6}
vQ",rP%
7U,[Ruu
return n; \]=''C=J
} M\rZr3
kt;uB X3
}a?(}{z-
} F2:nL`]b[
g<(\#F}/
JRYCM}C]
/* Yfd0Np~
**SiteInfoBean.java #Li6RSeW
*/ <*F!A' w2o
package NetFox; v%$c_'d
n/Fx2QC{
l}MVk%[
public class SiteInfoBean { {GP#/5$=
Qf#=Y j
wXKg^%t\
private String sSiteURL; //Site's URL ZD;1{
private String sFilePath; //Saved File's Path x@*!MC#
private String sFileName; //Saved File's Name ?)V?6"fFP
private int nSplitter; //Count of Splited Downloading File Xdtyer%
O=;}VZ<9
_my!YS5n
public SiteInfoBean() .Gq]Mrim9G
{//nSplitter的缺省值为5 +Cg[!6[#
//default value of nSplitter is 5 =Y`e?\#`
this("","","",5); 0wnC"2GUX
} 7Z[6_WD3
)N'rYS'9
sRKoM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e[l#r>NT
{ (R|Ftjs .
sSiteURL= sURL; MlH0
sFilePath = sPath; 6O0CF}B*
sFileName = sName; VteMsL/H
this.nSplitter = nSpiltter; YM.Q?p4g
>%1mx\y^
Oz-;2
} 6h9Hf$'
/|#";QsPN
6TkV+\
public String getSSiteURL() 'S#D+oF(1~
{ ;U<}2M!g
return sSiteURL; cl1>S3
} Or<OmxJg
oj%(@6L
GX0S9s
public void setSSiteURL(String value) K$kI%eGZA
{ :xy4JRcF
sSiteURL = value; i!u:]14>
} mGP&NOR0^y
>\4"k4d}
R8N*. [
public String getSFilePath() Of.%rpgy
{ Mp,aQ0bNS
return sFilePath; %ki^XB86
} !si}m~K!_
Q.i_?a
Tx:S{n7&
public void setSFilePath(String value) ]gjB%R[.m
{ EAZLo;
sFilePath = value; Z%$tV3a?
} 7;r Jr&.)
h;DLD8L
w tSX(LNY
public String getSFileName() n=qu?xu
{ iOXsj
return sFileName; hZwJ@ Vm#
} %Rm`+
!cNw8"SIU
N.F//n
public void setSFileName(String value) ]o2jSD
{ 5-2#H?:U
sFileName = value; MN<uIqG
} /v8yE9N_
Yc p<N>)
P TMJ.;
public int getNSplitter() s~>0<3{5
{ W'"p:Uhq
return nSplitter; #M@Ki1
} |*v w(
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k@}g?X`8
public void setNSplitter(int nCount) L=9^Y/8Q
{ &e)V!o@wJV
nSplitter = nCount; P&sYS<9q
} B2T=O%
} 2#)z%K6T
ioJ|-@!#o
#,CK;h9jy!
/* "|nh=!L
**Utility.java (8Q*NZ
*/ Zonr/sA~
package NetFox; IutU~%wv
/zg|I?$>Z4
8>AST,
public class Utility { V(wANvH
'dJ(x
0HPqoen$
public Utility() bwyj[:6l
{ T )!kJ;vc
uy rS6e0
w^E$R
} HyC826~-rI
@&9,0x
//线程睡眠 )QAS7w#k
public static void sleep(int nSecond) l|sC\;S
{ g]Z@_
try{ O#n=mJ
Thread.sleep(nSecond); dM)x|b3z
} ;5&=I|xqe
catch(Exception e) S+7u,%n/
{ Z3O_K
e.printStackTrace (); Lq]t6o]
} LO@o`JF
} bzyy;`;6Q~
6<Txkk
//日志 A@ZsL
public static void log(String sMsg) Wa<SYJ
{ Lk2;\D>
System.err.println(sMsg); "U|u-ka8B
} :wY(</H
v{;^>"5o
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public static void log(int sMsg) "5@\"L
{ se*!OiOt
System.err.println(sMsg); a\*_b2 ^n
} (d*~Qpi{7
} % 8P8h%%Z
C`["4
Qb#iT}!p%
/* vVf%wei^#
**TestMethod.java TpRI+*\
*/ MQMc=Z4d
package NetFox; ,A[NcFdCB
W.nr&yiQ
l#&\,T
public class TestMethod { D_M73s!U
Kb~i9x&
#k|f%!-Vo
public TestMethod() -0>s`ruor
{ ///xx/weblogic60b2_win.exe ->)0jZax
try{ Jvr`9<`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); En{< OMg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5 51p* B2
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y*0j/91
fileFetch.start(); 6kHuKxY,
} hxkwT
catch(Exception e){e.printStackTrace ();} ~;vt{pk
IVso/!
$fAZ^
} ?X@uR5?{
@dc4v_9
\[<8AV"E-'
public static void main(String[] args) n'83P%x
{ `{H!V~42
new TestMethod(); Ntlbn&lc;D
} i|!W;2KL5
} 0?*":o30
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