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)); wGxH
} sFsf~|
for(int i=0;i<nEndPos.length-1;i++) Xx\,<8Xn
{ g1Osd7\o
nEndPos = nStartPos[i+1]; s3VD6xi7
} 2)-4?uz~
nEndPos[nEndPos.length-1] = nFileLength; 8fPTxvXqL
} >oC{YYcK
} 2W#^^4^+
Ns5P,[pBOZ
-x|!?u5F
//启动子线程 s5)y%,E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %N0m$*
for(int i=0;i<nStartPos.length;i++) dAy\IfZX=
{ M;YJpi
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 32`Z3-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WADEDl&,'
nStartPos,nEndPos,i); %al 5 {
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QXgfjo
fileSplitterFetch.start(); %OP|%^2
} ^sqzlF
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M0`1o p1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p8Z;QH*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #L57d
nEndPos = " + nFileLength); dqO]2d
// fileSplitterFetch[nPos.length-1].start(); =r3g:j/>q
L$y~\1-
lr@w1*
//等待子线程结束 VCvf'$4(X
//int count = 0; VmRfnH"
//是否结束while循环 oe!4ng[
boolean breakWhile = false; YGRb|P-
4vCUVo r
.}:*tvot
while(!bStop) 4t>"-/
{ 5hTScnL%
write_nPos(); `7[!bCl
Utility.sleep(500); $9: @M.
breakWhile = true; ,Z}ST|$u
"<^n@=g'q
W>:MK-_J
for(int i=0;i<nStartPos.length;i++) NQqNBI?cr
{ `,4@;j<^@
if(!fileSplitterFetch.bDownOver) M}q;\}
{ '`f+QP=`
breakWhile = false; C &y 2I
break; c;zk{dP
} |nGv:= H@
} |$~]|SK
if(breakWhile) v5U'ky:
break; 9<3fH J?vq
#zBqj;p
u7j,Vc'~
//count++; $\bVu2&I
//if(count>4) VN'\c3;
// siteStop(); =%s6QFR
} NytodVZ'3
#&1gVkvp
q03+FLEfC
System.err.println("文件下载结束！"); # s7e/GdKb
} T8x8TN"
catch(Exception e){e.printStackTrace ();} 1kR. .p<"
} IM5[O}aq
};<?W){!H
gQJLqs"F
//获得文件长度 bbDm6,
public long getFileSize() uX]]wj-R3
{ <K,X5ctM}
int nFileLength = -1; eZ-fy,E
try{ WNKg>$M
URL url = new URL(siteInfoBean.getSSiteURL()); B<n[yiJ}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o[i*i<jv-
httpConnection.setRequestProperty("User-Agent","NetFox"); dDD5OnWmJ
Of-xGoYZ
(U_HX2f
int responseCode=httpConnection.getResponseCode(); yK$aVK"
if(responseCode>=400) ,KU%"{6
{ 'hV(1Mw
processErrorCode(responseCode); 62y:i
return -2; //-2 represent access is error R0LWuE%eD
} 1&<o3)L:
%d%?\jVb
aAG']y
String sHeader; E'5KJn;_7
3d4A~!Iz
O'{kNr{u
for(int i=1;;i++) ~*<`PDO?
{ 9Oo`4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q/d?cLgl
//Utility.log(in.readLine()); yPs6_Qo!p
sHeader=httpConnection.getHeaderFieldKey(i); >Gk<a
if(sHeader!=null) 5SmJ'zFO
{ *ZFF$0}
if(sHeader.equals("Content-Length")) J9DI(`
{ P#`M8k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z%iPk'^
break; z( }w|
} -;FAS3(wy
} ;Krb/qr4_
else }xi?vAaTl
break; Ei\>gXTH1-
} l&:8 'k+%=
} X%kJ3{
catch(IOException e){e.printStackTrace ();} kM&-t&7
catch(Exception e){e.printStackTrace ();} X.[bgvm~C
b{{ H@LTW
DS>&|zF5l
Utility.log(nFileLength); O:pg+o&
`'k2gq&
NGkxg:
return nFileLength; uOy/c 8`
} f?ibyoXL
^;.u}W
'}B"071)<
//保存下载信息（文件指针位置） "PO8Q
private void write_nPos() ~J>;l s1
{ qSG0TWD!pq
try{ $`ptSR
output = new DataOutputStream(new FileOutputStream(tmpFile)); (Z[c7
output.writeInt(nStartPos.length); !MOsP<2
for(int i=0;i<nStartPos.length;i++) p@uHzu7
{ QjG/H0*mP
// output.writeLong(nPos); ,|>>z#Rr(n
output.writeLong(fileSplitterFetch.nStartPos); O!XSU,
output.writeLong(fileSplitterFetch.nEndPos); Dq$1 j%4Y
} XMT@<'fI
output.close(); ITTEUw~+o
} OdY9g2y#m
catch(IOException e){e.printStackTrace ();} Mx`';z8~
catch(Exception e){e.printStackTrace ();} (w5cp!qW9J
} GEh(pJ
Zv=pS (9
6 R})KIG
//读取保存的下载信息（文件指针位置） ;v2eAe@7
private void read_nPos() ?eX/vqk
{ s@7hoU-+
try{ ~ss6yQ$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JoiGuZd>
int nCount = input.readInt(); a`#lYM%(>
nStartPos = new long[nCount]; 6o\uv
nEndPos = new long[nCount]; II.:k.D`
for(int i=0;i<nStartPos.length;i++) zNoFM/1Vb
{ 3o?eUwI}
nStartPos = input.readLong(); 'VCuMCV
nEndPos = input.readLong(); .r6x9t
} Ddg!1SF
input.close(); Q~svtN
} N#"l82^H*
catch(IOException e){e.printStackTrace ();} eL(<p]
catch(Exception e){e.printStackTrace ();} K/f-9hE F
} 5|K[WvG@Co
"G.X=, V
3Wv^{|^
private void processErrorCode(int nErrorCode) n5.sx|bI?
{ xsJXf @
System.err.println("Error Code : " + nErrorCode); 6vE#$(n#a&
} DwGM+)!
;R#RdUFH
Rk#'^}
//停止文件下载 y2s(]#8
public void siteStop() B>!mD{N
{ JW^ ${4
bStop = true; 7g+T
for(int i=0;i<nStartPos.length;i++) 42"nbJ
fileSplitterFetch.splitterStop(); DgW@v[#BK=
T@IzfX7
F!)[H["_
} ,f:K)^yD
} !3k-' ),z&
//负责部分文件的抓取 {4Kvr4)4
**FileSplitterFetch.java .<z7$lz\
*/ 2(l0Lq*
package NetFox; "B (?|r%
3.BUWMD
7]T(=gg /
import java.io.*; ")i)vXF'
import java.net.*; IjRUr\l
WH1" HO
C5I7\9F)
public class FileSplitterFetch extends Thread { iO?^y(phC
C12V_)~2
W4d32+V
String sURL; //File URL Ti_G
long nStartPos; //File Snippet Start Position \X%FM"r
long nEndPos; //File Snippet End Position ``VE<:2+
int nThreadID; //Thread's ID i.)n#@M2
boolean bDownOver = false; //Downing is over !<=zFy[J.9
boolean bStop = false; //Stop identical n(eo_.W2|
FileAccessI fileAccessI = null; //File Access interface Jk&!(YK&
z`E=V
a@W9\b@I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \ Voly
{ 0q-lyVZ^X
this.sURL = sURL; 7>O`UT<t4@
this.nStartPos = nStart; 8uLS7\,$z
this.nEndPos = nEnd; o)@nnqa
nThreadID = id; $[fqTh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8_HBcZWs
} Nr2,m"R{
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(P-^ PNz&
public void run() 'hBnV xd&
{ !JrKTB%
while(nStartPos < nEndPos && !bStop) a<r,LE
{ ez[x8M>
{._'Q[
{Oy|c
try{ "%^_.Db>|
URL url = new URL(sURL); a}FyJp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6#CswSpS
httpConnection.setRequestProperty("User-Agent","NetFox"); J.4U;A5
String sProperty = "bytes="+nStartPos+"-"; ]9/A=p?J@
httpConnection.setRequestProperty("RANGE",sProperty); 8YlZ({f
Utility.log(sProperty); HOWpTu(
r1%{\<
%?gG-R
InputStream input = httpConnection.getInputStream(); U-1UWq
//logResponseHead(httpConnection); !fn%Q'S
H<i!C|AF
fTy:Re
byte[] b = new byte[1024]; l5H5!$3~
int nRead; |LQ%sV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c8uw_6#r(D
{ 1[Yl8W%pj
nStartPos += fileAccessI.write(b,0,nRead); ?|W3RK;
//if(nThreadID == 1) 67Pmnad
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zc)nDyn
} E#(e2Z=
4uoZw3O
QH(&Cu,
Utility.log("Thread " + nThreadID + " is over!"); k $gcQ:|
bDownOver = true; Sj(>G;
//nPos = fileAccessI.write (b,0,nRead); vJ'22)n
} -kLBq:M
catch(Exception e){e.printStackTrace ();} h092S|iY
} |U{~t<BF#
} _yN5sLLyb
$aJay]F
ZOV,yuD{8{
//打印回应的头信息 zi6J|u
public void logResponseHead(HttpURLConnection con) 6z U
{ n8;L_43U
for(int i=1;;i++) xk>cdgt
{ \^dse
String header=con.getHeaderFieldKey(i); }WC[<AqI
if(header!=null) qF bj~ec
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @~ke=w6&pe
Utility.log(header+" : "+con.getHeaderField(header)); v%*don
else ]`x+wWe
break; q`2dL)E
} ">wvd*w0"(
} e7xv~C>g
(!{*@?S
U~ a\v8l~
public void splitterStop() @Drl5C}+
{ SQK82/
bStop = true; 8ly)G
} K(upzn*a
us|Hb
1DcBF@3sWG
} Q}B]b-c+E
\a;xJzc9
-avxH?;?7
/* >e6OlIW
**FileAccess.java ]h`*w
*//文件访问(定位，写) 18F}3t??
package NetFox; q9ra
import java.io.*; nD eVYK
(nB[aM
5Q8 H8!^
public class FileAccessI implements Serializable{ y-.{){uaD
\v-I<"::
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 au50%sA~
RandomAccessFile oSavedFile; U'" #jT
long nPos; [#@lsI
qtAt=` s
--l UEo~
public FileAccessI() throws IOException 7M~/ q.
{ xP_%d,
this("",0); *Xk5H,:
} |33t5}we
9;{(.K
c8mh#Tbl
public FileAccessI(String sName,long nPos) throws IOException .gC.T`/m
{ |VaJ70\o
oSavedFile = new RandomAccessFile(sName,"rw"); 3^ UoK
this.nPos = nPos; _p:n\9k
oSavedFile.seek(nPos); k6(</uRj
} [Y*>x2X
Rjq\$aY}%
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public synchronized int write(byte[] b,int nStart,int nLen) dI%jR&.e;
{ ZPE-
int n = -1; em,1Yn?
try{ d*Mqs}8
oSavedFile.write(b,nStart,nLen); fNAW4I I}
n = nLen; $[`rY D/.
} F%p DF\
catch(IOException e) {c3FJ5:
{ /Q7q2Ne^*
e.printStackTrace (); aG;F=e
} H:hM(m0?q
-V4{tIQY
qVfn(rZ
return n; HM)D/CO,?
} )s:kQ~+
|0}Xb|+
T\p>wiY2|F
} `!N}u
? Pi|`W
Z_bVCe{
/* VS ECD;u4c
**SiteInfoBean.java uZL,%pF3A
*/ K!9K^h
package NetFox; /77cjesZ9
S[$9_Jf
<S7SH-{_\
public class SiteInfoBean { j$_?g!I=gK
^cPVnl
&S+*1<|`K
private String sSiteURL; //Site's URL z6J12tu
private String sFilePath; //Saved File's Path K!ogpd&X&
private String sFileName; //Saved File's Name $#n9C79Z@
private int nSplitter; //Count of Splited Downloading File IxUj(l1Fm
oh$"?N7n1
:^`j:B
public SiteInfoBean() n6Uh%rO7S|
{//nSplitter的缺省值为5 c3l(,5DtH
//default value of nSplitter is 5 fgL"\d}
this("","","",5); ,sc#l<v
} xV+\R/)x
?K pDEH~\
u{=h%d/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +Eb-|dM
{ V2?{ebx`
sSiteURL= sURL; yc]_?S>9
sFilePath = sPath; "4WnDd5"
sFileName = sName; +pT;; 9
this.nSplitter = nSpiltter; Jxe5y3* (
U3B&3K} ~
"zNS6I?rzE
} 2"a%%fv
l]&A5tz3
3 $%#n*
public String getSSiteURL() ,2Ed^!`
{ ZGH 7_K
return sSiteURL; FLQke"6i0:
} m=E/um[D
:kI[Pf!z
X4:84
public void setSSiteURL(String value) jbe:"Stw
{ JE:LA+ (
sSiteURL = value; lGp:rw`
} {~51h}>b#
L''VBY"?
-eV*I>G
public String getSFilePath() ,^mEi
{ y~]D402Cx
return sFilePath; zFFYl7]
} "wV
3)>re&
Q`J U[nY
public void setSFilePath(String value) W?E01"p
{ y=\&z&3$
sFilePath = value; ,)\G<q yO6
} Ag:/iB]
rusM]Z
E%E`\mFD
public String getSFileName() "&D0Sd@[?
{ |wb_im
return sFileName; K%%Ow
} }T}c%p
emJZ+:%
"dndhoMq
public void setSFileName(String value) !X"nN9k
{ Iw?^
sFileName = value; d=+zOF
} YSB> WBS-<
9({ 9r[U
;6 d-+(@
public int getNSplitter() )N^fSenFBn
{ c{D<+XM
return nSplitter; hA/Es?U]
} +7WpJ;C4
p[WlcbBwT
~yXDN4s
public void setNSplitter(int nCount) R=R]0
{ U"@p3$2QW
nSplitter = nCount; En-=z`j G
} (]mBAQ#hw
} JM0+-,dl[
M^l%*QF[,q
ueW/i
/* e]!`94f
**Utility.java s]=XAm"4
*/ 0#yH<h$
package NetFox; ?^-fivzS>
h^IizrqU
Qt'3v"S>)
public class Utility { Tp~Qg{%Og
Gl{2"!mt=
&u"mFweS
public Utility() 1GR|$E
{ &?@U_emLi
fRk'\jzT
%T<c8w}dP
} ~9!@BL\
9@M;\ @&g
//线程睡眠 eUa:@cA
public static void sleep(int nSecond) ri3*~?k00
{ OS L~a_
try{ Y~( 8<`^
Thread.sleep(nSecond); 2" v{
} IwbV+mWQ
catch(Exception e) Vfq-H/+
{ 2}P{7flDY
e.printStackTrace (); g(jn /Cx
} lnMU5[g{
} ="@f~~
nyhHXVRH
//日志 c0jTQMe4yl
public static void log(String sMsg) J~@W":v
{ ;6]ag< Q
System.err.println(sMsg); bS|h~B]rd
} S[8nGH#m
{}Afah
ed/ "OgA
public static void log(int sMsg) )WEOqaR]
{ N1:)Z`r
System.err.println(sMsg); ow,! 7|m
} }DvT6
} N^[MeG,8
$RRh}w\0^
vls+E o]
/* b\NY!)B
**TestMethod.java bWCtRli}
*/ #'#@H
package NetFox; *gwo.s
Xe ^NVF
h^H)p`[Gme
public class TestMethod { A}uWy^w
SrMfd7H8f
#;P-*P
public TestMethod() L`w_Q2{sv
{ ///xx/weblogic60b2_win.exe [4])\q^q
try{ HR'F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6_w~#86=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7}mrC@[i
SiteFileFetch fileFetch = new SiteFileFetch(bean); uXGAcUx(
fileFetch.start(); loyhNT=
} &$pQ Jf
catch(Exception e){e.printStackTrace ();} \$,;@H5I^
1NN#-U
&6\E'bBt
} A(C0/|#V
+I.{y
JVx-4?
public static void main(String[] args) (3m^@2i
{ 1q*=4O
new TestMethod(); D|C!KF (
} )h%tEY$AJ
} Lp{uA4:=K
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