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)); FO{=^I5YA
} 1 ZdB6U0
for(int i=0;i<nEndPos.length-1;i++) %6K7uvTq
{ t)SZ2G1r
nEndPos = nStartPos[i+1]; |IxHtg3>6{
} OL'Ito
nEndPos[nEndPos.length-1] = nFileLength; P.~UUS
} Vk5Z[w a
} C@M-_Ud>Q
8%rD/b6`
WMbkKC.{J
//启动子线程 ChBf:`e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,H7X_KbFD4
for(int i=0;i<nStartPos.length;i++) Ee>VA_ss
{ dQ:,pe7A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z]7 WC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), r>mBe;[TX
nStartPos,nEndPos,i); u6iW1,#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _3IT3mb2n
fileSplitterFetch.start(); "be\%W+<
} 'nmGHorp
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4.A^5J'W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q^X7x_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w,|@e_|J
nEndPos = " + nFileLength); ns[/M~_r
// fileSplitterFetch[nPos.length-1].start(); 5eAZfe%H
UmKE]1Yw4r
I}$`gUXX8x
//等待子线程结束 '|yxB')
//int count = 0; (P>nA3:UXB
//是否结束while循环 *,u3Wm|7
boolean breakWhile = false; 2=cx`"a$
+LHU}'|
*CN *G"
while(!bStop) d3%qYL_+a
{ f-U zFlU
write_nPos(); kBUkE-~
Utility.sleep(500); D?Oe";"/
breakWhile = true; ]4~Yi1]
+IZ=E >a
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for(int i=0;i<nStartPos.length;i++) "&(/bdah?&
{ H4M=&"ll}
if(!fileSplitterFetch.bDownOver) V 6}5^W
{ 6@]o,O
breakWhile = false; $q!A1Fgk0
break; (Tx_`rO4VY
} 0aT:Gy;
} m:BzIcW<\
if(breakWhile) ]2zM~
break; Jv~R/qaaD
+%5L2/n7
<H64L*,5'7
//count++; :8S;34Y;
//if(count>4) 74e=zW?
// siteStop(); b42%^E
} ;@+|]I
FgdnX2s J
cXXZ'y>FP
System.err.println("文件下载结束！"); -"-.Z&#
} ,fjY|ip
catch(Exception e){e.printStackTrace ();} Qt u;_
} rrIyZ@_d9
A}fm).Wp@
hs6pp/h>
//获得文件长度 M+"6VtZH
public long getFileSize() #p+iwW-
{ HDm]njF%qQ
int nFileLength = -1; 2gWR2 H@
try{ wd:Yy
URL url = new URL(siteInfoBean.getSSiteURL()); 9qX$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YS3~sA
httpConnection.setRequestProperty("User-Agent","NetFox"); WZa6*pF
-TD\?Q
}L0 [Jo:
int responseCode=httpConnection.getResponseCode(); (bm^R-SbB
if(responseCode>=400) MqJTRBs%
{ Zo UeLU
processErrorCode(responseCode); B*/!s7c.
return -2; //-2 represent access is error DG&'x;K"$
} 8Qi)E1n
}$oS/bo
c[2t,+O
String sHeader; 3ynkf77cn
|bk9<i ?
~[=<Os
for(int i=1;;i++) S1|5+PPs
{ $f@YQN=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?N4FB*x
//Utility.log(in.readLine()); .!q_jl%U
sHeader=httpConnection.getHeaderFieldKey(i); k26C=tlkv"
if(sHeader!=null) RvG=GJJ9
{ ,#;hI{E
if(sHeader.equals("Content-Length")) MkW=sD_
{ V7,dx@J-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cvcZ\y
break; &mX_\w/%
} 8K4^05*S
} *+v*VH
else I<}% L V
break; lIyMNw
} 9L$OSy|
} tR51Pw
catch(IOException e){e.printStackTrace ();} GR|\OJ<2
catch(Exception e){e.printStackTrace ();} P!-RZEt$
b5MBzFw
bo<P%$(D
Utility.log(nFileLength); HMVP71
*iB&tWv
eb7UA=[Z
return nFileLength; 3cHYe
} hh4R
Cab-:2L]
1$RJzHS
//保存下载信息（文件指针位置） J0V m&TY
private void write_nPos() ILr=<j
{ 1;[KBYUH
try{ +cfcr*
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8SpG/gl"
output.writeInt(nStartPos.length); { <Gyjq
for(int i=0;i<nStartPos.length;i++) ;PaU"z+Je~
{ NU=2*gM
// output.writeLong(nPos); rp\`uj*D
output.writeLong(fileSplitterFetch.nStartPos); 0n:cmML)D
output.writeLong(fileSplitterFetch.nEndPos); `M~R4lr
} :G>w MMv&z
output.close(); I^EZs6~
} =r+K2]z,L
catch(IOException e){e.printStackTrace ();} x8aOXN#w}
catch(Exception e){e.printStackTrace ();} LZ wCe$1
} yF\yxdUX#
Gd A!8
WVD48}HF-
//读取保存的下载信息（文件指针位置） yKhI&
private void read_nPos() z~2{`pET
{ W=HvMD
try{ XaCvBQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jyD~ER}J
int nCount = input.readInt(); CHTK.%AQH!
nStartPos = new long[nCount]; n*"r!&Dg
nEndPos = new long[nCount]; 1\}XL=BE
for(int i=0;i<nStartPos.length;i++) Z,"4f*2
{ .Wt3|?\=nd
nStartPos = input.readLong(); %%ouf06.|
nEndPos = input.readLong(); (Yz[SK=U}
} a0hBF4+6
input.close(); [.4{s
} e1g3a1tnWl
catch(IOException e){e.printStackTrace ();} /4O))}TX
catch(Exception e){e.printStackTrace ();} WowT!0$
} $y6 <2w%b
U;/2\Ii
QM8Ic,QFvo
private void processErrorCode(int nErrorCode) R*vQvO%)h
{ ,c"J[$i$
System.err.println("Error Code : " + nErrorCode); |Uics:cQC
} {C&Uq#V
1UK= t
"dP-e
//停止文件下载 ,c:NdY(,)
public void siteStop() zg3kU65PJE
{ uD@ZM
bStop = true; FD[*Q2fU
for(int i=0;i<nStartPos.length;i++) O*v&CHd3
fileSplitterFetch.splitterStop(); vyDxX
_yg;5#3
Lfn$Q3}O`$
} :!MEBqcU
} {U2AAQSa
//负责部分文件的抓取 HL&HY)W1gf
**FileSplitterFetch.java 0)SRLHTY%
*/ dV[G-p
package NetFox; WP*}X7IS
tx7 zG.,
2*Qi4%s#
import java.io.*; $ (;:4
import java.net.*; |'-aR@xJ
!#pc@(rE
;@=3 @v
public class FileSplitterFetch extends Thread { ;[;WEA
t@R[:n;+
wxqX42v
String sURL; //File URL mDK*LL5]W
long nStartPos; //File Snippet Start Position -&D=4,#
long nEndPos; //File Snippet End Position K@*+;6y@
int nThreadID; //Thread's ID I'*,<BPG
boolean bDownOver = false; //Downing is over @Dfg6<0
boolean bStop = false; //Stop identical rX)&U4#[m
FileAccessI fileAccessI = null; //File Access interface v4hrS\M
3N$@K"qM#
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &(,\~
{ 4/~x+tdc
this.sURL = sURL; Jy/< {7j
this.nStartPos = nStart; lv=q( &
this.nEndPos = nEnd; b5H}0<
nThreadID = id; {Z k^J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7YD+zd:
} FWJ**J
4_5f4%S
HSysME1X:/
public void run() tkZUjQIX
{ s8&q8r7%
while(nStartPos < nEndPos && !bStop) Z@1kx3Wx$
{ d7](fw@c
[L2+k? *
OGg\VV'
try{ F/ZFO5C%
URL url = new URL(sURL); |P]W#~Y-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }O7sP^
httpConnection.setRequestProperty("User-Agent","NetFox"); )Xg5=zn$
String sProperty = "bytes="+nStartPos+"-"; UH-873AK
httpConnection.setRequestProperty("RANGE",sProperty); rmzzbLTu
Utility.log(sProperty); Fc@R,9
YA,~qT|
lND2Kb
InputStream input = httpConnection.getInputStream(); OC*28)
//logResponseHead(httpConnection); IrQ.[?C
4 9N.P;b
nrMW5>&-`
byte[] b = new byte[1024]; >)<?
int nRead; }P?e31@:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1W'Ai"DLw
{ SbGdcCB
nStartPos += fileAccessI.write(b,0,nRead); 7qyPI
//if(nThreadID == 1) z*h:Nt%.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2j8GJU/L
} te(H6c#0
uCr& `
BJwuN
Utility.log("Thread " + nThreadID + " is over!"); F8Ety^9>9
bDownOver = true; #?w07/~L
//nPos = fileAccessI.write (b,0,nRead); LH2B*8=^2
} =_#b .8K
catch(Exception e){e.printStackTrace ();} sR1_L/.
} 5?;<^J
} 7tlK'j'
k5E2{&wZ
3bWGWI
//打印回应的头信息 _Z]l=5d
public void logResponseHead(HttpURLConnection con) 'wEQvCS
{ <z\SKR[
for(int i=1;;i++) |Jn|GnM
{ Is4,QnY_[
String header=con.getHeaderFieldKey(i); g0j)k6<6(Y
if(header!=null) `;Tf_6c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ywJ [WfCY
Utility.log(header+" : "+con.getHeaderField(header)); #epbc K
else g6%]uCFB
break; 4+q,[m-$(
} :41Y
} L0"|4=
0\XWdTj{
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public void splitterStop() .4^+q9M
{ _aevaWtEx
bStop = true; \85%d0@3
} }y6@YfV${
nDdY~f.B
~'lT8 n_
} syBpF:`-W
1<'z)r4
D/Ki^E
/* /al56n
**FileAccess.java FTCIfW
*//文件访问(定位，写) <VhmtT%7
package NetFox; THhxj)
import java.io.*; _y[C52,
R 9`[C
QIMd`c
public class FileAccessI implements Serializable{ S'34](9n6
Y"bm4&'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B-N//ef}
RandomAccessFile oSavedFile; 8c.>6 Hy
long nPos; sPi
IrL7%?
bK%F_v3'
public FileAccessI() throws IOException P}8hK
{ %>Gb]dv?
this("",0); :4V5p =v-
} UCcr>
@>O7/d?O
[T r7SU#x
public FileAccessI(String sName,long nPos) throws IOException Dst;sLr[,
{ ^WB[uFt-
oSavedFile = new RandomAccessFile(sName,"rw"); 9f0`HvHC
this.nPos = nPos; y[$UeE"0
oSavedFile.seek(nPos); Bbs1U
} 0]7jb_n1
6Sd:5eTEQ
M,JwoKyg
public synchronized int write(byte[] b,int nStart,int nLen) }PK4 KRn
{ k*;U?C!
int n = -1; 5%2~/ "
try{ HDKF>S_S
oSavedFile.write(b,nStart,nLen); f]pHJVgFV
n = nLen; qix$ }(P
} G?M<B~}
catch(IOException e) k~0#Iy_{M
{ r*q
e.printStackTrace (); cv{icz,%w
} 3u 'VPF2
JRw<v4pZ
Ao )\/AR'
return n; ybC0Ee@
} Aaw]=8 OI
~hZr1hT6L
exZgk2[0
} 2jVvK"C
'^n,)oA/G
.Ei#mG-=}&
/* QO/nUl0E
**SiteInfoBean.java !.G knDT
*/ A'tv[Td8,
package NetFox; I!?)}d
q90 ~)n?
e**<et.
public class SiteInfoBean { *g*~+B :
\y(ZeNs
XtZeT~/7RT
private String sSiteURL; //Site's URL zv-9z
private String sFilePath; //Saved File's Path R?3N><oh*
private String sFileName; //Saved File's Name <Fi*wV
private int nSplitter; //Count of Splited Downloading File 34 '[O
z"D0Th`S6
#ZC9=
public SiteInfoBean() * lJkk
{//nSplitter的缺省值为5 { v [
//default value of nSplitter is 5 Al3*? H&
this("","","",5); s$JO3-)
} {/|tVc63
DO 0
hAV@/oQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) dw-o71(1d
{ cGSG}m@B`
sSiteURL= sURL; ${5E
sFilePath = sPath; G@3Jw[t
sFileName = sName; ?{;7\1[4
this.nSplitter = nSpiltter; IkuE|
NI:3hfs
<^w4+5sT/
} C"0vMUZ
K8JshFIe
5^97#;Q;J"
public String getSSiteURL() ,_UTeW6M
{ 1{<r~
return sSiteURL; +w2 `
} l*z+<c6$_
KJ7-Vl>
`)tIXMn
public void setSSiteURL(String value) \62!{
{ rhDiIO_
sSiteURL = value; 4 'DEdx,&f
} gle<{ `
r+usMF<'
iOtf7.@
public String getSFilePath() h-]c
{ R:`)*=rL%
return sFilePath; +xuj]J
} $=5kn>[_Z%
=u`tlN5pOT
@Hl+]arUh
public void setSFilePath(String value) G+t=+T2m
{ oL7F^34;
sFilePath = value; h2y<vO
} FY)US>
X4JSI%E
3$9V4v@2
public String getSFileName() 2v<O}
{ )S`=y-L$
return sFileName; 7$v_#ZE.H
} bs'hA@r
Js&.p9S2
5FE&
public void setSFileName(String value) f#\Nz>tOhE
{ A*{CT>
sFileName = value; +`ug?`_
} hGcu(kAC,
9TZ6c
@V Sr'?7-
public int getNSplitter() :_h#A}8Xd
{ Ek60[a
return nSplitter; q<K/q"0-l
} NFPWh3),f
lMgPwvs'
v\+`n^=
public void setNSplitter(int nCount) r)Ja\;
{ Y(Y#H$w
nSplitter = nCount; ]QQeUxi
} FzAzAl5
} ,Fn-SrB:
?aguAqG$
;?y~ h$
/* #itZ~tol
**Utility.java =imJ0V~RW
*/ /i{V21(%
package NetFox; ^mouWw)a_
TPYh<p#
?KWo1
public class Utility { @p@b6iLpO
$$XeCPs0
"8Lv
public Utility() rN,T}M=2
{ L^=G(op*
<`u_O!h
i]Bu7Fuu
} -@XOe&q
AwZz}J+
//线程睡眠 Ph)>;jU
public static void sleep(int nSecond) 7~SnY\B|
{ o+Mc%O Z
try{ et/v/Hvw1
Thread.sleep(nSecond); 8~F?%!X
} >uYU_/y$2
catch(Exception e) x.sC015Id
{ oPVt qQ
e.printStackTrace (); r^{Bw1+
} B=%x#em
} 7nsovWp
UjMWSPEBy
//日志 ZSr!L@S
public static void log(String sMsg) ?g:sAR'
{ W\<HUd
System.err.println(sMsg); bq9/d4
} )iJv?Y\]
D^}2ilk!
<`?%Cz AO
public static void log(int sMsg) z0%tBgqY(
{ hVl@7B~
System.err.println(sMsg); vpC?JXz=H
} VB`% u=
} fYW9Zbov-
n:f&4uKoG<
=G !]_d0
/* ^9><qKbO
**TestMethod.java |7Qe{
*/ \Yn0|j>
package NetFox; 5~d=,;yE
pK ^$^*#
zRgAmX/g
public class TestMethod { < FY%QB)h
[,{Nu EI
";/ogFi
public TestMethod() )i_:[ l6
{ ///xx/weblogic60b2_win.exe de;CEm<n
try{ !N!AO(Z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5#y_EpL"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oArXP\#
SiteFileFetch fileFetch = new SiteFileFetch(bean); j6j4M,UI43
fileFetch.start(); #. 71O#!
} BO8?{~i
catch(Exception e){e.printStackTrace ();} 4$81ilBcL
<8YvsJ
ah,"c9YX
} wk{]eD%
LB[?kpy
`xZ,*G7(*
public static void main(String[] args) |9p0"#4u
{ CSz+cS
new TestMethod(); :F9Oj1lM%
} bkz/V/Y
} +(W7hK4ip
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