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)); RKtU@MX49
} .DN)ck:e;
for(int i=0;i<nEndPos.length-1;i++) Y| 2Gj(*8
{ V")u y&Ob
nEndPos = nStartPos[i+1]; gu|cQ2xV
} UgC{
nEndPos[nEndPos.length-1] = nFileLength; gBPYGci2F
} (-bLP
} ? f>pKe
2J1YrHj3
/xh/M@G3
//启动子线程 1 [D,Mu%E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NB#-W4NA
for(int i=0;i<nStartPos.length;i++) syB.Z-Cpd
{ 3?Tk[m1b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Dqg~g|(Q<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G\ m`{jv
nStartPos,nEndPos,i); .j l|?o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tMOhH #
fileSplitterFetch.start(); i286`SLU
} 7 yp}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q3P*&6wA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >u/ T`$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <xO" E%t
nEndPos = " + nFileLength); wu`P=-
// fileSplitterFetch[nPos.length-1].start(); D\9-MXc1
a%NSL6
pe@j`Sm:Ej
//等待子线程结束 9LK<u$C
//int count = 0; {OGv1\ol&
//是否结束while循环 k]] e8>
boolean breakWhile = false; pdEUDuX
"+k^8ki
wzNGL{3
while(!bStop) aPH6R<G
{ o3kVcX^
write_nPos(); e>~7RN
Utility.sleep(500); ^R;rrn{^
breakWhile = true; xp;CYr"1}
/j(3 ~%]o4
k*"FMJG_
for(int i=0;i<nStartPos.length;i++) O$,bNu/g
{ ZMn~QU_5
if(!fileSplitterFetch.bDownOver) (sN;B)
{ 'rSP@
breakWhile = false; IuN:*P
break; 0.kQqy~5
} i-E/#zni
} FAbl5VW'
if(breakWhile) :W*']8 M-
break; _=ziw|zI
w\(;>e@
$CP_oEb
//count++; ,HHCgN
//if(count>4) C'oNGOEd
// siteStop(); ,3p$Z
} #24eogo~
;:#g\|(<+
% >}{SS
System.err.println("文件下载结束！"); \$[; d:9j
} ML-?#jNa<
catch(Exception e){e.printStackTrace ();} dWDM{t\}\
} \Zbi`;m?
{ZR>`'^:
vAH`tPi>
//获得文件长度 KDEcR
public long getFileSize() =*Ru2
{ FdFN4{<QZ
int nFileLength = -1; |xX>AMZc)D
try{ 3Sh#7"K3
URL url = new URL(siteInfoBean.getSSiteURL()); Qk h}=3u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gK+/wTQ%
httpConnection.setRequestProperty("User-Agent","NetFox"); R^ &nBwp
H){lXR/#u
+x_9IvaW&?
int responseCode=httpConnection.getResponseCode(); 29~Bu5
if(responseCode>=400) 2Pz)vnV"
{ NU{`eM
processErrorCode(responseCode); N"Mw1R4
return -2; //-2 represent access is error ux=0N]lc
} A$;"9F@
%IhUQ6
*!-J"h
String sHeader; }<KQ+
F* h\#?
9?L,DThQ
for(int i=1;;i++) KVA~|j B
{ AttS?TZr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &m8Z3+Ea
//Utility.log(in.readLine()); Dg~L"
sHeader=httpConnection.getHeaderFieldKey(i); dub%fs
if(sHeader!=null) [44C`x[8M+
{ V9cKl[
if(sHeader.equals("Content-Length")) GT3?)g{Z
{ 4ht+u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uqFYa bU
break; bz4TbGg]
} ^j>w<ljzz
} TeXt'G=M
else /lqVMlz\77
break; 2ms@CQy(00
} _oBJ'8R\
} \Uh$%#}.
catch(IOException e){e.printStackTrace ();} GO<,zOqvU
catch(Exception e){e.printStackTrace ();} "B"Yfg[
m2h@*
*%;+3SV
Utility.log(nFileLength); A1uo@W
`Eq~W@';Q0
{Xw6p
return nFileLength; f tE2@}
} Ptj[9R
/.>8e%)
{M&Vh]
//保存下载信息（文件指针位置） "2 "gTS
private void write_nPos() I/V lH:o
{ _&xi})E^O]
try{ lU&[){
output = new DataOutputStream(new FileOutputStream(tmpFile)); KYN{Dh]-}
output.writeInt(nStartPos.length); I`-N]sf^
for(int i=0;i<nStartPos.length;i++) @&fAR2
{ Rt=zqfJ
// output.writeLong(nPos); roNRbA]
output.writeLong(fileSplitterFetch.nStartPos); j,@@[{tu
output.writeLong(fileSplitterFetch.nEndPos); Ap)[;_9BD
} f9FEH7S68
output.close(); Fh0cOp(
} waRK$/b (
catch(IOException e){e.printStackTrace ();} ^Pp2T
catch(Exception e){e.printStackTrace ();} Z36C7 kw
} 7 S6@[-E
|b^+= "
CYFi_6MFl
//读取保存的下载信息（文件指针位置） /t"FZ#
private void read_nPos() O4lHR6M2
{ vn"+x_
try{ i0/RvrLc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Pua|Z x
int nCount = input.readInt(); {>rGe#Vu
nStartPos = new long[nCount]; wR]jJbF
nEndPos = new long[nCount]; !]*Cwbh. u
for(int i=0;i<nStartPos.length;i++) ?=#vp /
{ o +KDK{MD
nStartPos = input.readLong(); yMVlTO
nEndPos = input.readLong(); #|R#/Yc@Bv
} kACgP!~/1
input.close(); K0xka[x=(
} YggeKN
catch(IOException e){e.printStackTrace ();} C(@#I7G
catch(Exception e){e.printStackTrace ();} 05PRlz*x=
} jqv"8S5
CaE1h9
RJhafUJ zH
private void processErrorCode(int nErrorCode) OPe3p {]
{ )oAxt70
System.err.println("Error Code : " + nErrorCode); lNRGlTD%
} SR8)4:aKW
Q!*}^W
|S0nR<x-M
//停止文件下载 1~aP)q
public void siteStop() o4PJ9x5R!
{ ~4^~w#R
bStop = true; n> tru L
for(int i=0;i<nStartPos.length;i++) [~&yLccN
fileSplitterFetch.splitterStop(); ~OSgpM#O!T
b<bj5m4fz>
[Rxbb+,U
} p'f8?jt
} 7H!/et?S,
//负责部分文件的抓取 Q/zlU@
**FileSplitterFetch.java ;eY.4/*R
*/ !> 2kH
package NetFox; E>I\m!ue
)Bw}T
rZ#ZY
import java.io.*; HzQY\Y6
import java.net.*; iKM!>Fi
$s]vZ(H
ZULnS*V;5
public class FileSplitterFetch extends Thread { !%X#;{
zN3b`K. i
Uu_Es{@
String sURL; //File URL @ Cd#\D|
long nStartPos; //File Snippet Start Position -~] q?k?
long nEndPos; //File Snippet End Position A~)#
int nThreadID; //Thread's ID AC&)FY
boolean bDownOver = false; //Downing is over mxEniy
boolean bStop = false; //Stop identical ^gSZzJ5
FileAccessI fileAccessI = null; //File Access interface $+
i9koh3R\
'B\7P*L"p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fHd|tl
{ %5$)w;p.$'
this.sURL = sURL; mJNw<T4!/
this.nStartPos = nStart; E^4}l2m_
this.nEndPos = nEnd; ;_p$5GVR|
nThreadID = id; w&[&ZDsK
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;V0^uB.z
} W"n0x8~sV
K 7OIT2-
?>/9ae^Bw
public void run() 7SJR_G6,{
{ .L@gq/x)
while(nStartPos < nEndPos && !bStop) #1De#uZ
{ NH'Dz6K5
zvbO q
bYUG4+rD
try{ \k 6'[ln
URL url = new URL(sURL); H):(8/>(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %WF]mF T_
httpConnection.setRequestProperty("User-Agent","NetFox"); ,n3e8qd
String sProperty = "bytes="+nStartPos+"-"; _J"fgxW
httpConnection.setRequestProperty("RANGE",sProperty); aY-7K._</
Utility.log(sProperty); Fs(FI\^
0fzHEL
y|/[;
InputStream input = httpConnection.getInputStream(); =1Hn<Xay0
//logResponseHead(httpConnection); p?2^JJpUb
\,S4-~(:!
/b7]NC%
byte[] b = new byte[1024]; 92x)Pc^D
int nRead; ]?%S0DO*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g{^~g
{ +Ly@5y"
nStartPos += fileAccessI.write(b,0,nRead); b4&l=^:e=
//if(nThreadID == 1) ?DGg.2f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E?- ~*T
} HA74s':FN
0[])wl
&u2H^ j
Utility.log("Thread " + nThreadID + " is over!"); xn=#4:f
bDownOver = true; %uw7sGz\
//nPos = fileAccessI.write (b,0,nRead); p1UYkmx[
} UvR.?js(O
catch(Exception e){e.printStackTrace ();} sBk|KG
} AO238RC!:
} <?F-v
[Ob09#B%:5
|Iknk,
//打印回应的头信息 kvG.?^ v
public void logResponseHead(HttpURLConnection con) {l"(EeW6)
{ uaE,F^p
for(int i=1;;i++) GL%)s?
{ )FN\jo!!.
String header=con.getHeaderFieldKey(i); z HT#bP:o
if(header!=null) #/> a`Ur_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wk#cJ`wG;
Utility.log(header+" : "+con.getHeaderField(header)); lVCnu>8
else $0R5 ]]db)
break; y$+=>p|d.^
} KM"BHaSkF
} jO-T1P']Y
@ZRg9M:N
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public void splitterStop() 1~Z
{ K@%gvLa\
bStop = true; 1-$+@Xl
} 2wu\.{6Zp
dVg'v7G&V(
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} R"j<C13;%
CG;+Z-"X
g:Q:cSg<
/* {n&GZG"f
**FileAccess.java Id1de>:;
*//文件访问(定位，写) orOq5?3
package NetFox; EU Z7?4o
import java.io.*; ~)F_FS
osc A\r
%(|-+cLW+
public class FileAccessI implements Serializable{ 8DX5bB
7 0PGbAD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m>|7&l_
RandomAccessFile oSavedFile; k[)/,1
long nPos; AZf69z
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|ZC'a!
public FileAccessI() throws IOException T% GR{mp
{ <Sr:pm
this("",0); B}nT>Ub
} &dPUd~&EL
Yxy!&hPLv:
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public FileAccessI(String sName,long nPos) throws IOException :|8!w
{ gF`hlYD
oSavedFile = new RandomAccessFile(sName,"rw"); Xvk+1:D
this.nPos = nPos; $&!|G-0'
oSavedFile.seek(nPos); <*+[E!oi
} UoaWI2
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g}S%D(~
public synchronized int write(byte[] b,int nStart,int nLen) f:t j
{ FY-eoq0O3
int n = -1; yY{
try{ YeVo=hYH@
oSavedFile.write(b,nStart,nLen); EEMRy
n = nLen; E62_k 0q
} Ls+vWfF=#
catch(IOException e) ej7L-~lxQ
{ zKI1
e.printStackTrace (); n1aOpz6`
} dd6%3L{cn
\%B7M]P
qQIX:HWDKZ
return n; 8)MWC:
} !@*= b1
{6%-/$LX
)c?nh3D
} 4;@L#Pzt
Z +O<IF%
<EdNF&S-
/* w+Gav4
**SiteInfoBean.java 2R ^6L@fw
*/ _0ZU I^#
package NetFox; _T7XCXEk
}346uF7C
Bz|/TV?X(
public class SiteInfoBean { 3bJ|L3G
I-=Ieq"R9
_k;HhLj`
private String sSiteURL; //Site's URL 2G<XA
private String sFilePath; //Saved File's Path u%6b|M@P
private String sFileName; //Saved File's Name LM 1Vsh<
private int nSplitter; //Count of Splited Downloading File 7G7"Zule*j
s}yN_D+V
TA8
public SiteInfoBean() OOXP1L
{//nSplitter的缺省值为5 -%Ce
//default value of nSplitter is 5 =diGuIB
this("","","",5); rg=Ym.
} 4?+jvVq
aL&9.L|1g
NTO.;S|2%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]>ndFE6kl
{ dc_2nF
sSiteURL= sURL; PRNq8nmxC
sFilePath = sPath; ; xQhq*
sFileName = sName; nywC]T
this.nSplitter = nSpiltter; ep0dT3&
<r(D\rmD
:6&#u.\u
} ]"?<y s
/1D.Ud^
i)Q d>(v
public String getSSiteURL() 5sj$XA?5
{ =;F7h @:
return sSiteURL; FD~ UF;VQ
} ;g;1<? [
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public void setSSiteURL(String value) aT+w6{%Z
{ /d/]#T[Z9
sSiteURL = value; i2;,\FI@t%
} Vg :''!4t2
P}>>$$b\Yi
Ab:ah7!
public String getSFilePath() ,rF!o_7
{ G:wO1f6
return sFilePath; 3OY(L`
} &}|`h8JA]K
@?;)x&<8?3
JoZzX{eu"
public void setSFilePath(String value) :Bu)cy#/[
{ _meW9)B
sFilePath = value; sY?wQ:
} rx@i.+
!,rF(pz
D~|q^Ms,%
public String getSFileName() 5*Qzw[[=
{ Y7 K2@257
return sFileName; k7L4~W
} R~|(]#com
${}9/(x/^
2- (}=N
public void setSFileName(String value) B@*!>R
{ :#{0yno)H
sFileName = value; k,; (`L
} *J >6i2M,u
yF_/.mI
_34%St!lg
public int getNSplitter() @v!#_%J
{ {x[C\vZsi]
return nSplitter; 4x?I,cAN
} o>T+fBHE
y\[* mgl:
,2i1 4H
public void setNSplitter(int nCount) fY #Yn
{ ne3t|JZ
nSplitter = nCount; l Ft&cy2
} tp }Bz&V
} wlslG^^(!
Fg'{K%t4
,^ dpn
/* \" m&WFm
**Utility.java Nez '1
*/ x{GFCy7
package NetFox; so| U&`G
<X5ge>.
$fT#Wva-\d
public class Utility { ,t9CP
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-7o-d-d F
public Utility() ac966<#
{ _\= /~>Xl
4cJ/XgX
*,*XOd:3TL
} |}/KueZ
Qw|y%Td8r
//线程睡眠 RzFxO
public static void sleep(int nSecond) Jw^my4
{ UlKg2p
try{ L'"c;FF02i
Thread.sleep(nSecond); BO6XY90(
} ,9ew75Jl
catch(Exception e) E @Rb+8},"
{ U!RIeC
e.printStackTrace (); a5d_= :S;
} TV0Y{x*~iH
} PGVp1TQ
oR7f3';?6
//日志 Bs>S2]
public static void log(String sMsg) "T<7j.P?
{ 5LU7}v~/
System.err.println(sMsg); sqjDh
} huR ^l
N+H[Y4c?F&
*A")A.R
public static void log(int sMsg) w vI v+Q9
{ ed3wj3@
System.err.println(sMsg); %\)AT"
} }g|9P SbJ
} / T_v8{D
0 N0< 4b
O#>,vf$
/* :!fY;c?
**TestMethod.java 1]A\@(
*/ "d M-3o<
package NetFox; |<y1<O>F
[(.lfa P
f'`y-]"V5)
public class TestMethod { Mpk7$=hjc
a"Ly9ovW
O0bOv S
public TestMethod() 1:./f|m
{ ///xx/weblogic60b2_win.exe I?%#`Rvu
try{ iU=:YPE+.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B)0;gWK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,W/Y@ScC
SiteFileFetch fileFetch = new SiteFileFetch(bean); z U*Mk
fileFetch.start(); AXnKhYlu
} (OavgJ+Y
catch(Exception e){e.printStackTrace ();} D$w?
-$@'@U
hQNUA|Q=%
} h7m$P^=U
&Wk:>9]Jrb
@ Yo*h"s
public static void main(String[] args) 9\kEyb$F=
{ 04}c_XFFE
new TestMethod(); Y;dqrA>@
} ]~ S zb
} nf:wJ-;*
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