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)); ?U08A{ c
} Xt =bc
for(int i=0;i<nEndPos.length-1;i++) E5 oD|'=WA
{ kDq%Y[6Z
nEndPos = nStartPos[i+1]; a1SOC=.M;
} v|@n8ED|@K
nEndPos[nEndPos.length-1] = nFileLength; BA-nxR
} wF8\
} + nS/jW
sK0VT"7K
6# ";W2
//启动子线程 fR4l4 GU?)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &|}IBu:T
for(int i=0;i<nStartPos.length;i++) JF%=Bc$C
{ Ts .Zl{B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ATM:As:<@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /\cu!yiX
nStartPos,nEndPos,i); ==1/N{{R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *t{c}Y&@
fileSplitterFetch.start(); O/9%"m:i
} WgJAr73 l
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *g4Cy8$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \.P}`Bpa
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %8CT -mQ
nEndPos = " + nFileLength); sLdUrD%
// fileSplitterFetch[nPos.length-1].start(); 4>VZk^%b#
1L8ULxi_?]
*}ee"eHs
//等待子线程结束 xg,]M/J
//int count = 0; MW$H/:3
//是否结束while循环 gkML .u
boolean breakWhile = false; 6'Yn|A
5A$az03y$\
?w37vsN
while(!bStop) }u_EXP8M
{ OI_/7@L
write_nPos(); *C@[5#CA2z
Utility.sleep(500); * \o$-6<
breakWhile = true; yC0f/O
`JWYPsWk
M1]6lg[si
for(int i=0;i<nStartPos.length;i++) 0*Km}?;0-
{ {IPn\Bka
if(!fileSplitterFetch.bDownOver) s i"`
{ e*2&s5 #RT
breakWhile = false; 0uIV6LI
break; w}W@M,.^
} ^UvK~5tBV
} r` `iC5Ii
if(breakWhile) rw8J:?0x
break; frmqBCVJ:
vbA7I<;
m-'(27
//count++; r($_>TS&"
//if(count>4) g)9JO6]
// siteStop(); 9VUm=Z#`
} I*W9VhIOV
NB+$ym
%kZ~xbY
System.err.println("文件下载结束！"); YR|(;B
} NT;x1
catch(Exception e){e.printStackTrace ();} iijd$Tv
} F8S~wW=\w
k>:/D
LZQFj/,Jg
//获得文件长度 )_9e@~,
public long getFileSize() DO1 JPeIi
{ D]pK=247
int nFileLength = -1; Tw`c6^%^y
try{ s3Krob`C5
URL url = new URL(siteInfoBean.getSSiteURL()); g]Xzio&w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7~kpRa@\P
httpConnection.setRequestProperty("User-Agent","NetFox"); xxLgC;>[
/OhaERv
nb0 Py>4
int responseCode=httpConnection.getResponseCode(); $kkp*3{ot
if(responseCode>=400) GP{$v:RG
{ hy$MV3LP
processErrorCode(responseCode); ol?z<53X]
return -2; //-2 represent access is error ,5eH2W
} Q{qj
t1n'Ecm(
~N>[7I"*
String sHeader; N{q5E,}
RVXRF_I
E$F)z
for(int i=1;;i++) TJ?}5h5
{ e@L+z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Kcsje_I-M
//Utility.log(in.readLine()); F2z^7n.S
sHeader=httpConnection.getHeaderFieldKey(i); 4AZlr*U
if(sHeader!=null) E{wVf_K
{ JBeC\ \QX
if(sHeader.equals("Content-Length")) 96}/;e]@
{ p#^L ZX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I]~xs0$4#
break; H1s{JJAM>i
} )n5]+VTZ5
} |>j=#2
else *h@nAB\3
break; #U"\v7C{n
} dm8veKW'l
} jMW|B
catch(IOException e){e.printStackTrace ();} #y-OkGS ^
catch(Exception e){e.printStackTrace ();} unSF;S<
0b?9LFd
;=_<\2
Utility.log(nFileLength); %/1`"M5ko
l"CHI*
,y:q]PR
return nFileLength; K*7*`6iU
} \8ulX>]
+\"@2mOH{+
h*_r=' E
//保存下载信息（文件指针位置） Z TjlGU `
private void write_nPos() )K8JDP
{ '9$xOrv
try{ >Q[]i4*A
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;6fkG/T
output.writeInt(nStartPos.length); `S;pn+5
for(int i=0;i<nStartPos.length;i++) -S)HB$8
{ {D1=TTr^
// output.writeLong(nPos); /bt@HFL|`
output.writeLong(fileSplitterFetch.nStartPos); @<>](4D
output.writeLong(fileSplitterFetch.nEndPos); ~qFi0<-M
} `9zP{p
output.close(); <%qbU-
} 5IVASqYp
catch(IOException e){e.printStackTrace ();} dkG-Yz~
catch(Exception e){e.printStackTrace ();} J@!Sf7k42
} 4&$hBn=!
@ mtv2P`
;d?4phl-.
//读取保存的下载信息（文件指针位置） {BJ[h
private void read_nPos() gbXzD`WQ
{ _4[kg)#+
try{ wy:.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N@tzYD|hA
int nCount = input.readInt(); xqbI~jV#
nStartPos = new long[nCount]; /x0zZ+}V
nEndPos = new long[nCount]; ^hY<avi6s
for(int i=0;i<nStartPos.length;i++) Pg*ZQE[ME8
{ c9r2kc3cy{
nStartPos = input.readLong(); 4;w_o9o
nEndPos = input.readLong(); ]#3=GFs/
} owmA]f
input.close(); 2MtaOG2l&q
} uh:
catch(IOException e){e.printStackTrace ();} al#yc
catch(Exception e){e.printStackTrace ();} \iu2rat^
} M#F;eK2pf
1xT^ ,e6
eR8h4M~O
private void processErrorCode(int nErrorCode) K<Iz5+oD
{ vERsrg;(
System.err.println("Error Code : " + nErrorCode); 96MRnj*Y[
} (iBBdB
.hETqE`E
Y,>])R[4
//停止文件下载 '=%vf
public void siteStop() j&Z:|WniK
{ Q\ro )r
bStop = true; )WKe,:C
for(int i=0;i<nStartPos.length;i++) "xnek8F
fileSplitterFetch.splitterStop(); {,P&05iSi
L7a+ #mGE
3&x_%R
} P9X/yZ42
} i1|-
//负责部分文件的抓取 )0qXZgs
**FileSplitterFetch.java @}aK\
*/ Yx XDRb\kW
package NetFox; s{<rc>
b$.N8W%
6j_ A{*~Ng
import java.io.*; YBHmd
import java.net.*; |D`Zi>lv
p]=8=pE<
|l7e*$j
public class FileSplitterFetch extends Thread { hvZW~ =75
ke)3*.Y%C
:^J(%zy
String sURL; //File URL LDwu?"P!
long nStartPos; //File Snippet Start Position 63-`3R?;
long nEndPos; //File Snippet End Position a/`fJY6rR
int nThreadID; //Thread's ID Z*s/%4On
boolean bDownOver = false; //Downing is over So0YvhZ+
boolean bStop = false; //Stop identical +>c)5Jih
FileAccessI fileAccessI = null; //File Access interface ;) (qRZd6
<f{m=Dc
DRf~l9f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >.J68x
{ nSgg'I(
this.sURL = sURL; tty6
this.nStartPos = nStart; shnfH
this.nEndPos = nEnd; HTkce,dQ
nThreadID = id; l|j&w[c[Q0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '<6Gz7O
} *"j_3vAx
49HtI9@
SZvw>=)a
public void run() tlqDY1
{ P%B1dRa
while(nStartPos < nEndPos && !bStop) Gash3}+
{ 'HW(RC0dR
D.R5-
5 BcuLRId:
try{ Kq6m5A]z
URL url = new URL(sURL); r/3!~??x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i!YZF$|
httpConnection.setRequestProperty("User-Agent","NetFox"); vAwFPqu
String sProperty = "bytes="+nStartPos+"-"; q)<5&|V
httpConnection.setRequestProperty("RANGE",sProperty); MH{vFA4:,
Utility.log(sProperty); kD MS7y<s
g<}EL[9[J
][wS}~):
InputStream input = httpConnection.getInputStream(); 5g/^wKhKG
//logResponseHead(httpConnection); 8q_3*++D
Z2*hQ`eE
G9Azd^3
byte[] b = new byte[1024]; SuGlNp>#qm
int nRead; EkWe6m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y%ER51+
{ fa5($jJ&
nStartPos += fileAccessI.write(b,0,nRead); vlzjALy
//if(nThreadID == 1) alHwN^GhP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &\Cvrxa
} Ldir'FW
3^1)W!n/
\EB]J\x<
Utility.log("Thread " + nThreadID + " is over!"); fp12-Hk ~
bDownOver = true; -b)p6>G-C
//nPos = fileAccessI.write (b,0,nRead); 2Ni{wg"
} a7#Eyw^H{
catch(Exception e){e.printStackTrace ();} zS?i@e $
} tGM)"u-
} B;1wnKdj
"NC(^\l/
Im6ymaf9
//打印回应的头信息 nwcT8b87J
public void logResponseHead(HttpURLConnection con) 0b*a2_|8k
{ u$<FKp;I
for(int i=1;;i++) :peBQ{bj
{ DB?_E{y]
String header=con.getHeaderFieldKey(i); r OB\u|Pg
if(header!=null) xW"J@OiKL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q&M(wnl5
Utility.log(header+" : "+con.getHeaderField(header)); rD$7;
else O@E&lP6
break; K<+AJ(C
} %$sWNn
} wJ IJPYTK
#+ n &
|l)Oy#W
public void splitterStop() -P'>~W,~
{ ,FBF;zED
bStop = true; HJg)c;u/2;
} O5k's
*j<;;z-
\V: _Zs
} 7Jc=`Zm'
pF"z)E|^
WQ"ZQ
/* zh50]tX
**FileAccess.java #axRg=d?K
*//文件访问(定位，写) \19XDqf8
package NetFox; ]/d2*#
import java.io.*; 70KXBu<6
&V$'{
w_|WberU
public class FileAccessI implements Serializable{ 7c;59$2(
p1Lx\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \ 2".Kb@=
RandomAccessFile oSavedFile; ""WZpaw
long nPos; a`|/*{
.!9]I'9M
F ^E(AE
public FileAccessI() throws IOException IOmIkx&`GP
{ YnI
this("",0); *]Vx=7D
} H56e#:[$
Wa[~)A
gNZ^TeT
public FileAccessI(String sName,long nPos) throws IOException 8Q6il-
{ SULWPH5Pr
oSavedFile = new RandomAccessFile(sName,"rw"); gXH89n
this.nPos = nPos; EG9S? $
oSavedFile.seek(nPos); T>?sPq
} }.T$bj1B;V
_fa]2I
=#+Z KD
public synchronized int write(byte[] b,int nStart,int nLen) H!45w;,I
{ Ap97Zcw
int n = -1; Y[x ^59
try{ sO(Kpo9jq
oSavedFile.write(b,nStart,nLen); UiYA#m
n = nLen; ]AHi$Xx
} |u$AzI
catch(IOException e) z%;\q$
{ uF^+}Y ZT
e.printStackTrace (); F^Q
} pP".?|n
0kiW629o
f}+G;a9Nj
return n; [C d2L&9
} }wv$ #H[
fqZ!Bi
J'7){C"G$
} PGw"\-F
wCI.jGSBW
liU=5BL
/* m&$H?yXW>
**SiteInfoBean.java Nq9(O#}
*/ IO6i
package NetFox; h1Q7(8=Eg
^qk$W?pX
Xbu >8d?n
public class SiteInfoBean { s!+?)bB
tSOF7N/<
>c1mwZS;
private String sSiteURL; //Site's URL 5Y,e}+I>
private String sFilePath; //Saved File's Path z_Qw's
private String sFileName; //Saved File's Name 5jsnE )
private int nSplitter; //Count of Splited Downloading File r":<1+07
Az.Y-O<$\
'+}hVfN
public SiteInfoBean() gbInSp`4
{//nSplitter的缺省值为5 -iW[cj R`$
//default value of nSplitter is 5 D<rjxP
this("","","",5); !IGVN:E
} *v8 ]99N
N.&K"J
qrdA?VV
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v h%\ " h
{ DvhK0L*Qr
sSiteURL= sURL; r]]Ke_s!
sFilePath = sPath; TIvLY5 HG
sFileName = sName; 95H`-A
this.nSplitter = nSpiltter; Np=*B_ @8
vfo[<"
]Wy V bIu
} fqr}tvMr=T
v)pdm\P
l'o}4am
public String getSSiteURL() !?+3jzG
{ )Z^(+
return sSiteURL; |C(72t?K
} fx}R7GN2
vw(};)8
zcNV<tx
public void setSSiteURL(String value) i\<l&W
{ *3k~%RM%?
sSiteURL = value; U^,ld`
} @.g4?c
W5x]bl#
v |i(peA#
public String getSFilePath() R]r~TJ o
{ Z os~1N]3
return sFilePath; TQEZ<B$
} gWlmQl
wWm#[f],?
/qp`xJ
public void setSFilePath(String value) u_[Zu8
{ fDRQ(}
sFilePath = value; x/Ds`\
} x x 'XR'zK
3!}#@<j
*U]f6Q<X
public String getSFileName() RM`8P5i]sF
{ V]<dh|x
return sFileName; b"zq3$6*
} r!zNcN(%cs
OC[a?#R1
Zkz:h7GUG-
public void setSFileName(String value) 95+}NJ;r
{ ;w+A38N$J
sFileName = value; ,wFLOfV@
} :._O.O
Te.hXCFD
~pw_*AN
public int getNSplitter() )Q\;N C=4
{ }8FP5Z'Cf%
return nSplitter; J:Qp(s-N^:
} MKH7d/x
Jsw<,uTD
"w A8J%:
public void setNSplitter(int nCount) 2.x3^/
{ ?&1?uc
nSplitter = nCount; !#X^nlc
} PEBQ|k8g&
} ^ ]B&7\w"t
z1L.
YnNei 7R
/* [oYe/<3
**Utility.java xWlB!r<}Gz
*/ qD9B[s8
package NetFox; kg-%:;y.
q|j;dI&
3Fr}8Dy
public class Utility { [Y:HVr,
l"vT@g|
GY4yZa
public Utility() ";zl6g"
{ * T~sR'K+|
bLUn0)c
!Q?4sAB
} > Euput\
g_}@/5?y
//线程睡眠 A#p@`|H#B
public static void sleep(int nSecond) :bh[6F
{ 3;Xs`dk
try{ JlH|=nIaj6
Thread.sleep(nSecond); iffU}ce
} |e\:0O?
catch(Exception e) ck^Z,AKL+
{ ,<[os
e.printStackTrace (); 0zfrx-'zN
} z,NHH):~
} )XNcy"
8cd,SQ}y
//日志 |W::\yu6
public static void log(String sMsg) / )EB~|4']
{ 7eq;dNB@gq
System.err.println(sMsg); d,H%
} zb3ir|
Nd0Wt4=
: Z.mM5
public static void log(int sMsg) ,cB`j7p(
{ ZuE0'9
System.err.println(sMsg); /@OGYYH,M
} a@X'oV`(2b
} I4)vJ0
~7=,)Q
vuK 5DG4
/* <.AIVp
**TestMethod.java EYQ!ELuF
*/ SrKF\h%/+
package NetFox; K}zw%!ex
Lf,gS*Tg?
G cbal:q
public class TestMethod { FX'W%_f,
~C[,P\,
' ZB%McS
public TestMethod() ~7k b4[
{ ///xx/weblogic60b2_win.exe j@:LMR>
try{ ?oF@q :W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }%}eyLm(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o 1b#q/
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0 Hq$h
fileFetch.start(); CUtk4;^y#
} c=K M[s.
catch(Exception e){e.printStackTrace ();} $51#xe
6ZM<M7(V
d EXw=u
} LO2sP"9
6m{3GKaW~
Z# :Ww
public static void main(String[] args) i7p3GBXh[
{ q80?C.,`
new TestMethod(); <k)rfv7
} 'J\%JAR@
} .d*vfE$
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