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)); 59u}W 0
} l/5 hp.
for(int i=0;i<nEndPos.length-1;i++) [/r(__.
{ ob]w;"
nEndPos = nStartPos[i+1]; ^2rN>k,?
} yG{TH0tq
nEndPos[nEndPos.length-1] = nFileLength; E1 2uZ$X
} FSO).=#
} F== p<lrs
XiWmV ?
K&-"d/QuLg
//启动子线程 !N^@4*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m&3xJuKih
for(int i=0;i<nStartPos.length;i++) ~} ~4
{ R;LP:,)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OyIw>Wfv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "AqB$^S9t
nStartPos,nEndPos,i); tH4B:Bgj!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #'`{Qv0,
fileSplitterFetch.start(); c:('W16
} HoAy_7-5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2=}FBA,2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [-w%/D%@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y~V(aih}D
nEndPos = " + nFileLength); .xkM.g4{~
// fileSplitterFetch[nPos.length-1].start(); i|kRK7[6B
c71y'hnT
!4!~Lk=
//等待子线程结束 bN.Pex
//int count = 0; -{vD:Il=6
//是否结束while循环 er\|i. Y
boolean breakWhile = false; dO\"?aiD
3so%gvY.'
l]SX@zTb
while(!bStop) j~MI<I+l[
{ zbiLP83
write_nPos(); rJB}qYD
Utility.sleep(500); Z_NCD`i;
breakWhile = true; =_^X3z0
* y,v}-
*^`Vz?g<
for(int i=0;i<nStartPos.length;i++) pj(,Zd[47
{ LP=)~K<
if(!fileSplitterFetch.bDownOver) RnN!2K
{ W,u:gzmhw
breakWhile = false; ;.C\Ss<>*
break; <UCl@5g&
} ,!9zrYi}
} ,zc(t<|-y
if(breakWhile) W g! Lfu
break; rC5O")I<
`vV7c`K?
!r-F>!~
//count++; Q2>gU#
//if(count>4) :Dp0?&_
// siteStop(); F'Z,]b'st3
} w-jVC^C]
5r0YA IJ
lhJ'bYI
System.err.println("文件下载结束！"); uAk.@nfiEv
} ?7A>+EY
catch(Exception e){e.printStackTrace ();} aq-~B~c`g
} GvAb`c=
xz]~ jL@-]
a'T;x`b8U,
//获得文件长度 dr"1s-D4IQ
public long getFileSize() x1a:u
{ fQFk+C
int nFileLength = -1; XPPdwTOr
try{ '%;m?t%q
URL url = new URL(siteInfoBean.getSSiteURL()); ^J{:x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PY'2h4IL
httpConnection.setRequestProperty("User-Agent","NetFox"); y7<|_:00
CJyevMf'
+[ZY:ZQ
int responseCode=httpConnection.getResponseCode(); &5;"#:ORcK
if(responseCode>=400) (k P9hcV
{ (m$Y<{)2
processErrorCode(responseCode); +`15le`R
return -2; //-2 represent access is error *WZA9G#V5
} 4ppz,L,4
JGZBL{8
n"8Yv~v*2j
String sHeader; EX"yxZ~
~6gPS 13
@F>D+=hS
for(int i=1;;i++) [>9is=>o.
{ >mkFV@`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jWgX_//!
//Utility.log(in.readLine()); H/Jbk*Q
sHeader=httpConnection.getHeaderFieldKey(i); +|f@^-
if(sHeader!=null) YYS0`
{ O0:q;<>z
if(sHeader.equals("Content-Length")) |BYRe1l6l
{ iRBfx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GX%g9f!O
break; )B*t :tN
} kf9X$d6
} m[2gdJK
else ig"L\ C"T
break; ^?|"L>y
} l"]V6!-U
} g{LP7D;6
catch(IOException e){e.printStackTrace ();} H*6W q
catch(Exception e){e.printStackTrace ();} R-14=|7a-
#;S*V"
v^PO|Z
Utility.log(nFileLength); NlXimq
1mJHued=6
sRfcF`7
return nFileLength; c",*h
} }a/Cro.~4
@]0%L0u
(%9$!v{3
//保存下载信息（文件指针位置） 0{mex4
private void write_nPos() k=^xVQuI
{ ?cZlN!
try{ [Qr"cR^
output = new DataOutputStream(new FileOutputStream(tmpFile)); !m$jk2<
output.writeInt(nStartPos.length); ,,TnIouy
for(int i=0;i<nStartPos.length;i++) qP;OaM CX
{ W3RT{\
// output.writeLong(nPos); ]'S^]
output.writeLong(fileSplitterFetch.nStartPos); 6B-16
output.writeLong(fileSplitterFetch.nEndPos); t,'<gI
} JtZ7ti
output.close(); =M-p/uB]
} wY}@'pzX
catch(IOException e){e.printStackTrace ();} s^SJY{
catch(Exception e){e.printStackTrace ();} ]^]wP]R_
} =H~j,K
u:EiwRW
`X8F`5&U\f
//读取保存的下载信息（文件指针位置） V.Mry`9-
private void read_nPos() TC"<g
{ QW"! (`K
try{ MQ4KdqgP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {Ha57Wk8D
int nCount = input.readInt(); \v/[6&|X0s
nStartPos = new long[nCount]; Ss`LLq0LO
nEndPos = new long[nCount]; _f{{( 7
for(int i=0;i<nStartPos.length;i++) Xr{v~bf
{ s`UJ1eJ
nStartPos = input.readLong(); 28nFRr
nEndPos = input.readLong(); SAz
} OJxl<Q=z
input.close(); }\LQ3y"[
} F!do~Z
catch(IOException e){e.printStackTrace ();} i9$ Av
catch(Exception e){e.printStackTrace ();} $8FUfJ1@
} snJ129}A
7o4\oRGV
'<M{)?
private void processErrorCode(int nErrorCode) uq{beC
{ ?4B`9<j8%
System.err.println("Error Code : " + nErrorCode); cNH7C"@GVu
} _G0x3
54/=G(F
(w{j6).3Dj
//停止文件下载 %3rP`A
public void siteStop() [ 3HfQ
{ ctUp=po
bStop = true; wS*E(IAl
for(int i=0;i<nStartPos.length;i++) Y ay?=Y{
fileSplitterFetch.splitterStop(); Mfs?x a
N;gfbh]
;\]@K6m/Ap
} *`U~?q}
} 0aAoV0fMDz
//负责部分文件的抓取 'VbiVLWD
**FileSplitterFetch.java 5)E @F9N
*/ S[N5 ikg
package NetFox; T;uX4,|(
F5Va+z,jg
+qoRP2
import java.io.*; b]y2+A.n
import java.net.*; _g.{MTQ
f5r0\7y0
@.C2LIb
public class FileSplitterFetch extends Thread { % `3jL7|
.u:GjL'$
a =QCp4^
String sURL; //File URL wj+*E6o-n
long nStartPos; //File Snippet Start Position $^P0F9~0
long nEndPos; //File Snippet End Position ZW}_DT0
int nThreadID; //Thread's ID 8_8l.!~
boolean bDownOver = false; //Downing is over =Uh$&m
boolean bStop = false; //Stop identical xA/D'
FileAccessI fileAccessI = null; //File Access interface RpF&\x>
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KSvE~h[#+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ys~x$
{ 7Wno':w8
this.sURL = sURL; pUTr!fR
this.nStartPos = nStart; rKn~qVls
this.nEndPos = nEnd; &vJH$R
nThreadID = id; :>*7=q=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _LPHPj^Pg
} xwr8`?]y
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/\Ef%@
public void run() 9UkBwS`
{ E3i4=!Y
while(nStartPos < nEndPos && !bStop) 6-I'>\U~
{ ,'+kBZOv
+H.`MZ=
FtZ?C@1/
try{ ;]iRk
URL url = new URL(sURL); -%~4W?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M{\I8oOg
httpConnection.setRequestProperty("User-Agent","NetFox"); q@&6#B
String sProperty = "bytes="+nStartPos+"-"; R@0R`Zs
httpConnection.setRequestProperty("RANGE",sProperty); p[-O( 3Y
Utility.log(sProperty); R2;
1,~D4lD|
y^k$Us
InputStream input = httpConnection.getInputStream(); KP"+e:a%
//logResponseHead(httpConnection); Rv=YFo[B
Vj-h;rB0z
74u&%Rj
byte[] b = new byte[1024]; <[phnU^ 8
int nRead; yuVs YV@"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GmG5[?)
{ AdmC&!nH
nStartPos += fileAccessI.write(b,0,nRead); :+Z%; Dc
//if(nThreadID == 1) =I4lL]>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >Q/Dk7#
} C}X\|J
,bd_:
dI2 V>vk
Utility.log("Thread " + nThreadID + " is over!"); dveiQ
bDownOver = true; ~@!bsLSMU
//nPos = fileAccessI.write (b,0,nRead); *#2h/Q.
} j+!v}*I![
catch(Exception e){e.printStackTrace ();} 9ati`-y2
} ~[ F`"
} )1z@
pw#-_
@L`jk+Y0vF
//打印回应的头信息 >sF)BoLc
public void logResponseHead(HttpURLConnection con) 4 :v=pZ
{ edD)TpmE,
for(int i=1;;i++) (BM47D=v
{ .d*8C,
String header=con.getHeaderFieldKey(i); FsPw1A$y
if(header!=null) :DNjhZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RNL9>7xV
Utility.log(header+" : "+con.getHeaderField(header)); D=$)n_F
else #z(]xI)"
break; 6LZCgdS{
} H+#FSdy#
} *v`eUQ:
&[9709 (=
r^ XVB`v
public void splitterStop() jCY%|
{ x38QD;MT
bStop = true; b$7 +;I;
} k'YTpO
zqku e%^?-
Smh,zCc>s
} 5(2;|I,T
h;Qk@F
>!JS:5|
/* 3%6?g*
**FileAccess.java zCA2X !7F
*//文件访问(定位，写) [Pp'Ye~K@c
package NetFox; J4'eI[73
import java.io.*; y7{?Ip4[
IBGrt^$M
]|@^1we
public class FileAccessI implements Serializable{ "4Nt\WQ
+_!QSU,@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~Ei<Z`3}7"
RandomAccessFile oSavedFile; h;Kx!5)y
long nPos; TpaInXR
CITc2v3a
<aw[XFg
public FileAccessI() throws IOException {:s f7
{ qK+5NF|
this("",0); Sdo-nt
} Ef\-VKh
hPh-+Hb
s~>}a
public FileAccessI(String sName,long nPos) throws IOException r%_djUd
{ U:`Kss`
oSavedFile = new RandomAccessFile(sName,"rw"); )BE1Q*= n
this.nPos = nPos; '"^'MXa
oSavedFile.seek(nPos); (:_$5&i7
} kM6 Qp
NbobliC=
e.>P8C<&
public synchronized int write(byte[] b,int nStart,int nLen) #E[0ys1O
{ 9?$i?
int n = -1; (Z*!#}z`
try{ .`lCWeHN
oSavedFile.write(b,nStart,nLen); 6863xOv{T
n = nLen; 1oS/`)
} #WuBL_nZ~
catch(IOException e) u, ff>/1
{ s7<AfaJPF
e.printStackTrace (); #spCtZE
} | Iib|HQ)
\bF{-"7.
H|*m$|$,
return n; [ 3Gf2_
} 8}[).d160
XX@ZQcN
T%Lx%Qn
} .>S!ji
Ba,`TJ%y
eRYK3W
/* \RiP
**SiteInfoBean.java vdZW%-A&\
*/ hM{bavd
package NetFox; #R"*c hLV
rsQtMtS2
3mgD(,(^
public class SiteInfoBean { 3<!7>]A
M7T5 ~/4
s*[bFJwN
private String sSiteURL; //Site's URL 8Wx=p#_
private String sFilePath; //Saved File's Path A<{{iBEI`
private String sFileName; //Saved File's Name d~H`CrQE*
private int nSplitter; //Count of Splited Downloading File 8r{.jFGv
|N2#ItBbW
Za9qjBH
public SiteInfoBean() tYS06P^<
{//nSplitter的缺省值为5 KHme&yMq
//default value of nSplitter is 5 ]`K2N
this("","","",5); `Oa WGZ[
} ~a:
Oz95
Pal=F0-Q\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &pRREu:[4L
{ "x-j~u?
sSiteURL= sURL; TDh5lI
sFilePath = sPath; N['.BN
sFileName = sName; tA;}h7/Lc~
this.nSplitter = nSpiltter; 8=l%5r^cq
kj_c%T ]/
wp_0+$?s
} Upe%rC(
u_enqC3
b;n[mk
public String getSSiteURL() J zl6eo[;
{ ,F|f. 7;
return sSiteURL; p2eGm-Erq
} }tz7b#
[WmM6UEVS
ueudRb
public void setSSiteURL(String value) G[=c Ss,
{ pP_LR ks}
sSiteURL = value; uFE)17E
} CZ;6@{ o
Y7|EIAU5Y
w{KavU5W
public String getSFilePath() Hka2
{ L,\Iasv
return sFilePath; aUp g u"
} 80I#TA6C
w:0E(z
p{_" bB
public void setSFilePath(String value) @C$]//;
{ s<Ziegmw|g
sFilePath = value; d=(mw_-?
} LoV<:|GTI
occ7zcA
K0~rN.C!0
public String getSFileName() ?4,T}@P
{ 1?}T=)3+$
return sFileName; DQ3<$0
} dN q$}
h{Y",7]!
N7"W{"3D
public void setSFileName(String value) h`q1
{ s;e\ pt
sFileName = value; 3`g^
} b}`TLn
[JiH\+XLPs
<I?Zk80
public int getNSplitter() -RwE%cr
{ fC`&g~yK'
return nSplitter; c{|p.hd
} $FVNCFN%
]^E?;1$f?
ye&;(30Oq
public void setNSplitter(int nCount) G{}VPcrbC
{ @JMiO^
nSplitter = nCount; C+$#y2"z#n
} $4LzcwG
} {)XTk&"
79gT+~z
N8jIMb'<
/* Cdn J&N{
**Utility.java TjH][bH5
*/ Y2AJ+ |
package NetFox; [n@] r2g)3
u`W2+S
_6Sp QW
public class Utility { B\~}3!j
oJ^P(]dw
X?O[r3<
public Utility() K;?+8(H
{ V[LglPt
>MZ/|`[M
ytImB`'\
} ?uu*L6
aE8VZ8tvq
//线程睡眠 Dt@SqX:~Ee
public static void sleep(int nSecond) Nn6%9PX_)
{ M`_0C38
try{ HMXE$d=[
Thread.sleep(nSecond); BmT!aue
} V3Bz Mw\9r
catch(Exception e) [agMfn
{ ,tFg4k[
e.printStackTrace (); YK_7ip.a[
} Rcuz(yS8
} 1MFbQs^
x}4q {P5$
//日志 9hl_|r~%*
public static void log(String sMsg) =X}J6|>X
{ .-zom~N-?
System.err.println(sMsg); &oNAv-m^GD
} Rq-ZL{LR7
-"x$ZnHU
]Wup/o
public static void log(int sMsg) W/N7vAx X
{ 5xiEPh
System.err.println(sMsg); ).O)p9
} KNl$3nX
} 0GLM(JmK
~%oR[B7=|
Eci\a]
/* P55fL-vo|}
**TestMethod.java }>\C{ClI
*/ kh<2BOV
package NetFox; ctQ/wrkU
:FF=a3/"6
4euO1=
public class TestMethod { %#+Hl0,Tt
vN $s|R'@
7GGUV
public TestMethod() (Ldi|jL
{ ///xx/weblogic60b2_win.exe bA 2pbjg=
try{ @Qe0! (_=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); btB%[]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \U0Q<ot/7
SiteFileFetch fileFetch = new SiteFileFetch(bean); S:}7q2:
fileFetch.start(); +T ?NH9
} 'u658Tj
catch(Exception e){e.printStackTrace ();} Om&Dw|xG8
/Oono6j
Ri'n
} +ZYn? #IQ
@EAbF>>
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public static void main(String[] args) NK+o1
{ KvSG;
new TestMethod(); 4i bc
} xw%0>K[
} {g6%(X\r.r
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