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)); B&0^3iKFi
} m?-3j65z
for(int i=0;i<nEndPos.length-1;i++) 05:`(vl
{ A~Eu_m
nEndPos = nStartPos[i+1]; p(MhDS\J
} UYH;15s
nEndPos[nEndPos.length-1] = nFileLength; >Fm}s,
} @<--5HbX
} Nt#zr]Fz
TH2D;uv
.+7GecYz
//启动子线程 %R5APMg1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n.C.th >Y1
for(int i=0;i<nStartPos.length;i++) =+q9R`!L]
{ BVxg=7%St
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SsDz>PP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RqW ZhHI1M
nStartPos,nEndPos,i); $]4^ENkI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CzxU @
fileSplitterFetch.start(); 1TfK"\
} hS&,Gm`^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gZgb-$b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a +Q9kh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0U]wEz*b
nEndPos = " + nFileLength); ks7g*; 3{@
// fileSplitterFetch[nPos.length-1].start(); 38!$9)
4VPL -":6
@`aR*B
//等待子线程结束 o|8 5<~`
//int count = 0; s)"C~w^
//是否结束while循环 D%umL/[]
boolean breakWhile = false; D;)Tm|XizW
^~(vP:
Zo`'xg
while(!bStop) &R/)#NAp
{ ,#&lNQ'I
write_nPos(); \`o+Le+%
Utility.sleep(500); &|u
breakWhile = true; OA2<jrGB!
} ab@Nd$
DW@PPvfs
for(int i=0;i<nStartPos.length;i++) y]9 3z!#Z
{ !8vHN=)z
if(!fileSplitterFetch.bDownOver) ys:1%D,,_
{ !!_K|}QOE
breakWhile = false; ?yzhk7j7
break; S2K_>kvG)~
} ^AMcZ6!\
} >e*m8gm#
if(breakWhile) A1@tp/L=o
break; ~fB: >ceD
ivC1=+
d<. hkNN
//count++; blph&[`}I
//if(count>4) st(l85
// siteStop(); 8Wid.o-U
} 6GG&mqr+
n'0^l?V
4)+MvKxjS
System.err.println("文件下载结束！"); aOfL;I
} #gi0FXL
catch(Exception e){e.printStackTrace ();} WV!qG6\W
} Rj9z'?a9
VYkOJAEBg
-_.)~)P
//获得文件长度 *PE1)bF
public long getFileSize() @jO3+
{ j]}A"8=1
int nFileLength = -1; d/Xbk%`p
try{ cu(2BDfiL
URL url = new URL(siteInfoBean.getSSiteURL()); 2V_C_5)1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y$!K<c k
httpConnection.setRequestProperty("User-Agent","NetFox"); `h_,I R<
oAe]/j$
]K0<DO9
int responseCode=httpConnection.getResponseCode(); UA/Q3)
if(responseCode>=400) V0z.w:-
{ G>&=rmK"
processErrorCode(responseCode); Y8`4K*58%
return -2; //-2 represent access is error B:)9hF?o@
} fLL_{o0T
|{+D65R
#9}E@GGs
String sHeader; ^kxkP}[Z.
! lgsV..R
P%f],f
for(int i=1;;i++) _ 0%sYkUc
{ 5j1}?0v_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oL>m}T
//Utility.log(in.readLine()); KOGbC`TN<
sHeader=httpConnection.getHeaderFieldKey(i); ,i#]&f`c;5
if(sHeader!=null) w-};\]I
{ s/UIo^m
if(sHeader.equals("Content-Length")) +I#4+0f
{ -fuSCj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k'}}eu/ q
break; sXOGIv
} jFpXTy[>
} 6UR.,*f=
else dG}fpQ3&
break; X{\>TOk
} +[8s9{1{C
} lBh|+KN
catch(IOException e){e.printStackTrace ();} vE7L> 7
catch(Exception e){e.printStackTrace ();} BbUZ,X*Y
L.>tJ.ID
F=yrqRS=
Utility.log(nFileLength); o!^':mll
5WgdgDb@L
lb5Y$ZC
return nFileLength; |[(4h
} pL8+gL
YuSe~~F)j
Dg%zNi2GS
//保存下载信息（文件指针位置） >3s9vdUp4h
private void write_nPos() *5]fjh{
{ 1u75
try{ ZN-J!e"`
output = new DataOutputStream(new FileOutputStream(tmpFile)); )Yz` 6
output.writeInt(nStartPos.length); V;mKJ.d${
for(int i=0;i<nStartPos.length;i++) yd[}?
{ p{xO+Nx1a
// output.writeLong(nPos); tiSN amvG1
output.writeLong(fileSplitterFetch.nStartPos); ;H/*%2
output.writeLong(fileSplitterFetch.nEndPos); RN238]K
} &^FCp'J-
output.close(); {EGiGwpf
} ~{iBm"4
catch(IOException e){e.printStackTrace ();} EMzJJe{Cv
catch(Exception e){e.printStackTrace ();} }legh:/*?O
} > nY<J
9"1 0:\U
eG9tn{
//读取保存的下载信息（文件指针位置） KL,=Z&.<=
private void read_nPos() dN\Byl(6
{ wQWokpP;T7
try{ 4_3Jpz*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); > xkl7D
int nCount = input.readInt(); 1s8v E f
nStartPos = new long[nCount]; 5t#+UR
nEndPos = new long[nCount]; i%+cPQ^o
for(int i=0;i<nStartPos.length;i++) G<OC99;8
{ 1VL!0H
nStartPos = input.readLong(); Q ,30
nEndPos = input.readLong(); zg+78
} N[d*_KN.!
input.close(); YpoO:
} b>=MG8
catch(IOException e){e.printStackTrace ();} ^'!]|^
catch(Exception e){e.printStackTrace ();} "8%B (a 5A
} J?Brnf.
/c'3I
wO&`3Q3~$
private void processErrorCode(int nErrorCode) _Sy-&}c+ +
{ @B %m,Mx
System.err.println("Error Code : " + nErrorCode); m]} E0
} Or= [2@Wg
=($RT
@'j=oTT
//停止文件下载 x$d3fsEE
public void siteStop() )n}Wb+2I
{ A\iDK10Q$
bStop = true; kLQPa[u4
for(int i=0;i<nStartPos.length;i++) :TJv<NZi'
fileSplitterFetch.splitterStop(); rM#jxAb
K@Q_q/(%;
H_m(7@=
} Iq0_X7:{QI
} T`7;Rl'Q
//负责部分文件的抓取 /~NsHStn
**FileSplitterFetch.java _*h,,Q
*/ eU'DQp*
package NetFox; `G&W%CHB
l-xKfp`
b|U&{I>TH
import java.io.*; }tv%
import java.net.*; *gfx'$
W&ya_iP~C
!c[(#g
public class FileSplitterFetch extends Thread { MKLntX
$,4;_4t
=k6zUw;5 U
String sURL; //File URL }Iz'#I Xx
long nStartPos; //File Snippet Start Position MO&QR-OY
long nEndPos; //File Snippet End Position S`gUSYS"w
int nThreadID; //Thread's ID 'uS!rKkQlu
boolean bDownOver = false; //Downing is over z=:<]j#=
boolean bStop = false; //Stop identical -jnx0{/
FileAccessI fileAccessI = null; //File Access interface |ybW
W.TZU'%
87P{vf#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [~9rp]<
{ #3vq+mcn
this.sURL = sURL; Og[NRd+
this.nStartPos = nStart; jOj`S%7
this.nEndPos = nEnd; ,0%P3
nThreadID = id; &M(=#pq9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /=I&-gxC
} 90L,.
(G $nN*rlu
aKXaor@0f.
public void run() t=syo->
{ [T#5$J
while(nStartPos < nEndPos && !bStop) rTYDa3
{ ;SoKX?up5
}VxbO8\b(
P3V=DOG"
try{ a3e<<<Z>R
URL url = new URL(sURL); |6w.m<p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c9imfA+e
httpConnection.setRequestProperty("User-Agent","NetFox"); ~L(=-B`Ow
String sProperty = "bytes="+nStartPos+"-"; BoZ])Y6=
httpConnection.setRequestProperty("RANGE",sProperty); RFd.L@-]
Utility.log(sProperty); ,g2|8>sJP
?;@xAj
x4|>HY<p?
InputStream input = httpConnection.getInputStream(); h1@|UxaE#
//logResponseHead(httpConnection); }[XzM/t
k<RJSK8
3kFSu
byte[] b = new byte[1024]; w^MU$ubx
int nRead; {WUW.(^]G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y>wrm:b-O
{ B5h-JON]-
nStartPos += fileAccessI.write(b,0,nRead); ?#?[6t
//if(nThreadID == 1) ks|[`FH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BqC, -gC
} LW6&^S?4{
=S/$h}Vi
e@'rY#:u
Utility.log("Thread " + nThreadID + " is over!"); }YJ(|z""
bDownOver = true; 3"=%[
//nPos = fileAccessI.write (b,0,nRead); 0jCYOl
} ^{&Vv(~!Q
catch(Exception e){e.printStackTrace ();} H?98^y7
} +shT}$cb1
} ;@p2s'(
OrP-+eg
sW!pMkd_
//打印回应的头信息 #k2&2W=x
public void logResponseHead(HttpURLConnection con) j~,7JJ (y
{ CqX2R:#
for(int i=1;;i++) 7uG@hL36
{ _"n1"%Ns
String header=con.getHeaderFieldKey(i); fTiqY72h
if(header!=null) 2GOQ|Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &09z`*,
Utility.log(header+" : "+con.getHeaderField(header)); }@MOkj
else >!O3 jb k
break; Nf8."EDUW
} YSwAu,$jf
} !Cxo4Twg
wHm{4
LX),oR
public void splitterStop() jv7-i'I@
{ bK;I:JK3
bStop = true; ^|y6oj
} eq.K77El{J
#g[jwl'
N),bhYS]
} (pM5B8U
S|!)_RL
a@`15O:
/* |_L\^T|6
**FileAccess.java !xmvCH=2
*//文件访问(定位，写) WccTR aq
package NetFox; 3a PCi>i!_
import java.io.*; edld(/wu~
Pk/{~!+ $
]-"~?
public class FileAccessI implements Serializable{ s\ft:a@
$z,lq#zzl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t"M&Yy
RandomAccessFile oSavedFile; 0,+RF"R
long nPos; %T@3-V_
gTWl];xja
MMg"G6?
public FileAccessI() throws IOException [of{~
{ ZN>oz@jY
this("",0); GJz d4kj
} Z$!>hiz2
B:S/ ?v
[1Pw2MC<
public FileAccessI(String sName,long nPos) throws IOException OAPR wOQ^=
{ (sLFJ a6e
oSavedFile = new RandomAccessFile(sName,"rw"); V`xZ4 i%L
this.nPos = nPos; WLGk
oSavedFile.seek(nPos); rX*4$d0
} $"&0
am,UUJ+h>
rFJ(t7\9h
public synchronized int write(byte[] b,int nStart,int nLen) 7U68|\fI!
{ $YuVM
int n = -1; 4i0~t~vDpr
try{ 3vRRL
oSavedFile.write(b,nStart,nLen); fwaq
n = nLen; LWgYGXWT"
} XnC`JO+7M
catch(IOException e) q\wT[W31@
{ t.wB\Kmt\
e.printStackTrace (); 1L722I@
} ,)%al76E
ELoE-b)Cb
o,l3j|1
return n; dL;C4[(N
} J6pQ){;6
q]Y [W1
4oW6&1
} Y1RiuJtL
<=WSX{_D
1F?`.~q
/* L=Cm0q 3v
**SiteInfoBean.java A0{ !m
*/ y4* }E
package NetFox; 3LXS}~&
*s4h tt
57r?`'#*
public class SiteInfoBean { bxX[$q
A[20ic
mqL&bmT
private String sSiteURL; //Site's URL iW.4'9
private String sFilePath; //Saved File's Path On%21L;JG
private String sFileName; //Saved File's Name Hc.r/
private int nSplitter; //Count of Splited Downloading File pzcV[E1
9_yO6)`
pw;
public SiteInfoBean() "fWAp*nI3t
{//nSplitter的缺省值为5 tMM*m
//default value of nSplitter is 5 0I6[`*|SX
this("","","",5); S[!sJ-rG
} &h)G>Sqc
/H 3u^
Vs@[="
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AITV+=sN
{ W vh3Y,|3
sSiteURL= sURL; Q1tZ]Q.6
sFilePath = sPath; TAfLC)
sFileName = sName; 5 :O7cBr
this.nSplitter = nSpiltter; m$nT#@l5bH
C1=7.dPr
^R\et.W`s
} !OwRx5
:4 9ttJl
R.n:W;^`
public String getSSiteURL() _@U?;73"5
{ ]Tmx;[D
return sSiteURL; jSMvZJX3n
} y&8' V\
+E.}k!y
i4 BCm/h
public void setSSiteURL(String value) 8r"$o1!
{ 6J/"1_
sSiteURL = value; .hI3Uv8[
} z?o16o-:
r$3{1HXc
O'tVZ!C#J
public String getSFilePath() RmXC ^VQ
{ "#7~}ZB
return sFilePath; z"4UObVs
} ~!o\uTVr
^kg[n908Nw
#H]cb#
public void setSFilePath(String value) 32DT]{-N!
{ CXC,@T
sFilePath = value; QcZ*dI7]:
} 7.hgne'<
/?<tjK' "H
*#ccz
public String getSFileName() =HJ)!(
{ _T[=7cn
return sFileName; th&?
} Wi a%rm
tI651Wm9
q5X\wz2N
public void setSFileName(String value) QWt?` h=
{ :U^!N8i"=
sFileName = value; Y\e,#y
} Af8&PhyrU
G$X+g{
foh>8/AL/
public int getNSplitter() f{ZOH<"Lo
{ =,Yi" E
return nSplitter; :?1r.n
} J*)Vpk
CiE
h-0sDt pR
public void setNSplitter(int nCount) CD$0Z
{ 9uk}r; %9
nSplitter = nCount; FD?!bI4
} jJ^p ?
} VCOz?Y*
{d`e9^Z:
S+c)
/* ~udi=J|
**Utility.java b"U{@
*/ ')pXQ
package NetFox; eKdF-;
r>fx55dw
]y*AA58;
public class Utility { MB$K ?"Y
$JKR,
.~#<>
public Utility() rLMjN#`^
{ F,2)Udim
C'bW3la
YGp8./ma<I
} YE<_a;yh1
0IHcyb
//线程睡眠 FBit/0
public static void sleep(int nSecond) I@dS/
{ nic7RN?F<
try{ ka_]s:>+
Thread.sleep(nSecond); gXtyl]K:
} Q+e|;Mj
catch(Exception e) plL##?<D<
{ RS&l68[6
e.printStackTrace (); J!?hajw7N
} x1['+!01
} #]nH$Kq
2{!o"6t
//日志 }Dk*Hs^E
public static void log(String sMsg) H8[L:VeNT
{ Fb#_(I[aj
System.err.println(sMsg); wLeP;u1
} 8l(_{Y5(-
Gc=#
.ztO._J7f
public static void log(int sMsg) y8T%g(
{ m`(5B
System.err.println(sMsg); fp^!?u
} (rfU=E
} _jmkAmeu
?m3,e&pB5
xA|72!zk0P
/* Fl,(KSTz
**TestMethod.java ^8S'=Bk
*/ n(-1vN
package NetFox; UEeD Nl$^u
3nVdws
96fzSZS,
public class TestMethod { LfD70r\
YEGRM$'`
9I0}:J;7
public TestMethod() m'h`%0Tc
{ ///xx/weblogic60b2_win.exe JGH;&UYP
try{ J!sIxwF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -h&AO\*^W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >;Er[Rywr
SiteFileFetch fileFetch = new SiteFileFetch(bean); mSSDV0Pfn
fileFetch.start(); `TvpKS5.Y
} I$@0FSl
catch(Exception e){e.printStackTrace ();} \$o5$/oU(
c]]OV7;)>
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} <uUHr,#
wfH#E2+pk
6C6<,c
public static void main(String[] args) d`>'<
{ D$|@: mW
new TestMethod(); aiP.\`>}
} <Wgp$qt;
} $5XE'm
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