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)); @%tXFizh
} [nN7qG
for(int i=0;i<nEndPos.length-1;i++) PW}OU9is
{ fF?6j
nEndPos = nStartPos[i+1]; +R$?2
} #?}6t~
nEndPos[nEndPos.length-1] = nFileLength; ed~R>F>
} &ju-
} .I?@o8'x
c $;\i
upn8n vy4(
//启动子线程 8?TKN~ja
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lpQP"%q
for(int i=0;i<nStartPos.length;i++) l_FGZ!7
{ a,'Cyv">
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \Z5+$Ij
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )&NAs
nStartPos,nEndPos,i); NlR"$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :x>T}C<Y
fileSplitterFetch.start(); #Olg(:\
} e]W0xC-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?z`MPdO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :jNYP{Br
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4yV].2#rl"
nEndPos = " + nFileLength); ;cP8?U
// fileSplitterFetch[nPos.length-1].start(); C;1PsSE+A
u,i]a#K
4~?2wvz G4
//等待子线程结束 #JNy
//int count = 0; gzfbzt}?
//是否结束while循环 -R+zeu(e'
boolean breakWhile = false; ;'kI/(;;C
T@+ClZi
(*^DN{5
while(!bStop) +!>LY
{ dBEIMn@
write_nPos(); MB$a82bY
Utility.sleep(500); '%4P;HO
breakWhile = true; ?#[)C=p]z
c;!g
W04av_u 5
for(int i=0;i<nStartPos.length;i++) P;foK)AM
{ 4!%]fg}Um
if(!fileSplitterFetch.bDownOver) NXoK@Y
{ 744=3v
breakWhile = false; =:$) Z
break; w$Ux?y-L
} to3?$-L
} 1 tfYsg=O
if(breakWhile) Ygj6(2
break; #a}N"*P
s"mFt{Y
H:}}t]E
//count++; lJ/6-dP
//if(count>4) ~Yk"Hos
// siteStop(); +mWjBY
} }5S2p@W)
Dt}dp_
??xlA-E
System.err.println("文件下载结束！"); ?vbDB4
} 0<P(M:a
catch(Exception e){e.printStackTrace ();} g{ (@uzqG
} Bhuw(KeB
8]*Q79
=y;@?=T
//获得文件长度 h)B!LAr
public long getFileSize() CyTFb$Z
{ lSCY5[?
int nFileLength = -1; Z] {@H
try{ jb@\i@-
URL url = new URL(siteInfoBean.getSSiteURL()); {g=b]yg\o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,?=KgG1i
httpConnection.setRequestProperty("User-Agent","NetFox"); z-Hkz
(&Q)EBdm
H1UL.g%d=
int responseCode=httpConnection.getResponseCode(); HWtPLlNt
if(responseCode>=400) !LSs9_w
{ K`+vfqX
processErrorCode(responseCode); ?[SVqj2-
return -2; //-2 represent access is error &l^n4
} BR3mAF
wixD\t59X
mTd<2Hy
String sHeader; #eEvF
YRa4W.&Yn
[t}):}~F|
for(int i=1;;i++) D0M!"c>\
{ GVp
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &q>h*w4O
//Utility.log(in.readLine()); q!*MH/R
sHeader=httpConnection.getHeaderFieldKey(i); c,BAa*]K
if(sHeader!=null) '5WN,Vy8.
{ i+U51t<
if(sHeader.equals("Content-Length")) z\$;'
{ |0w~P s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 59MR|Jt
break; cju@W]!
} \]a uSO
} PJwEA
else 3;D?|E]1
break; a(Sv,@/
} }9}w8R~E
} N[ Q#R~Hn<
catch(IOException e){e.printStackTrace ();} f(.6|mPp
catch(Exception e){e.printStackTrace ();} sN@j5p^jc
z|%Bh
o}!&y?mp
Utility.log(nFileLength); e[p^p!a
g^n;IE$B
ORtg>az\%
return nFileLength; Zjt9vS)
} ;qG1r@o
V<W02\Hs
[J:zE&aj
//保存下载信息（文件指针位置） P=pY8X:
private void write_nPos() !G>(j
{ C zpsqTQ
try{ 5:_~mlfi
output = new DataOutputStream(new FileOutputStream(tmpFile)); bXm:]?
output.writeInt(nStartPos.length); hLn&5jYHvt
for(int i=0;i<nStartPos.length;i++) #mTMt;x
{ o3= .T+B
// output.writeLong(nPos); '}fel5YV
output.writeLong(fileSplitterFetch.nStartPos); JOgmF_(>Z
output.writeLong(fileSplitterFetch.nEndPos); f-s~Q4
} -_w~JCx
output.close(); p}r yKW\cJ
} :7k`R62{
catch(IOException e){e.printStackTrace ();} 1J+3a-0
catch(Exception e){e.printStackTrace ();} :%>oe> _"
} KMe.i'
, Z4p0M
Nq U9/
//读取保存的下载信息（文件指针位置） 6BHPzv+Y
private void read_nPos() S#hu2\9D,
{ gm}C\q9
try{ SE-} XI\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %N1T{
int nCount = input.readInt(); _32/WQF6
nStartPos = new long[nCount]; LNbx3W oC
nEndPos = new long[nCount]; jiOf')d5
for(int i=0;i<nStartPos.length;i++) y,1S&k
{ <JJkki
nStartPos = input.readLong(); h bdEw=r?
nEndPos = input.readLong(); z.{HD9TD
} iPNd!_
input.close(); @u<0_r t
} l#|J rU!
catch(IOException e){e.printStackTrace ();} 'H FwP\HX
catch(Exception e){e.printStackTrace ();} (T4k~T`3
} UT% #K%
UzN8G$92qF
B\NcCp`5
private void processErrorCode(int nErrorCode) DZF[dxH
{ @eA %(C
System.err.println("Error Code : " + nErrorCode); mnQal>0~
} )m)h/_
JJ)y2
K"G(?<>~4c
//停止文件下载 f};!m=b
public void siteStop() ./2Z?,
{ ]+FX$+H/A0
bStop = true; 1.uUMW
for(int i=0;i<nStartPos.length;i++) KgL<}=S
fileSplitterFetch.splitterStop(); EOofa6f&l
+6wx58.B&
TR+Q4Y:
} SG1&a:c+.
} es{cn=\s
//负责部分文件的抓取 z`;&bg\8
**FileSplitterFetch.java S/KVN(Z
*/ )|MIWgfWN
package NetFox; ;}n|,g>
j#4+-
,K`E&hS
import java.io.*; <tGI]@Nwk
import java.net.*; ,,zd.9n
(cu'
_95- -\
public class FileSplitterFetch extends Thread { ;sm"\.jF
q.U*X5
!4i,%Z&6
String sURL; //File URL i#Ne'q;T
long nStartPos; //File Snippet Start Position G%y>:$rw[O
long nEndPos; //File Snippet End Position {/th`#o4b
int nThreadID; //Thread's ID (X0`1s
boolean bDownOver = false; //Downing is over Ax :3}
boolean bStop = false; //Stop identical 4o)(d=q
FileAccessI fileAccessI = null; //File Access interface <=#lRZW[z
)R8%wk?2
Ompi~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "m wl-=
{ (9Fabo\SH
this.sURL = sURL; F]/L!
this.nStartPos = nStart; .G7]&5s
this.nEndPos = nEnd; &?}kL= h
nThreadID = id; )w^GPlh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NKupOJJq
} ~%D^Ga7
jdV .{8@
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public void run() ~R"]LbeY
{ :|*Gnu
while(nStartPos < nEndPos && !bStop) /8 e2dw: \
{ f)p>nW?Z
Aqx3!
C.b,]7i
try{ Tb5$
URL url = new URL(sURL); x&Q+|b%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OL,/-;z6
httpConnection.setRequestProperty("User-Agent","NetFox"); !C9ps]6
String sProperty = "bytes="+nStartPos+"-"; $]Q*E4(kV9
httpConnection.setRequestProperty("RANGE",sProperty); ^.ZSpc}<
Utility.log(sProperty); JUe K"|fA
:w?:WH?2L
vLi/'|7
InputStream input = httpConnection.getInputStream(); ZX~>uf\n
//logResponseHead(httpConnection); >X-ed
sBeP;ox
)nf=eU4|
byte[] b = new byte[1024]; [ t>}SE
int nRead; oi33{#%t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^&f{beU9
{ Nb|3?c_
nStartPos += fileAccessI.write(b,0,nRead); =DeHxPv}f
//if(nThreadID == 1) +0oyt?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R=#q"9qz
} -6hu31W
z'vdC
Tx|SAa=V
Utility.log("Thread " + nThreadID + " is over!"); s$SU vo1J
bDownOver = true; XvfcPI6
//nPos = fileAccessI.write (b,0,nRead); q\\8b{~
} tEpIyC
catch(Exception e){e.printStackTrace ();} N'lGA;}i
} N(:EK
} XwHu:v'=
WI*^+E&=*
c%xED%X9
//打印回应的头信息 F]URf&U
public void logResponseHead(HttpURLConnection con) t z +
{ pXpLL_
for(int i=1;;i++) JxMyeo%gv
{ -z>Z0viA
String header=con.getHeaderFieldKey(i); 5WtQwN~
if(header!=null) (R;) 9I\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {UV<=R,E
Utility.log(header+" : "+con.getHeaderField(header)); Lic{'w&
else CYTuj>Ww
break; Ti9:'I
} Y:tW]
} Allt]P>
MHpL$g=5_
EyKkjEXx_
public void splitterStop() *<|~=*Ddf
{ ^cKv JSY
bStop = true; rC1qGzg\a
} !R] CmK
m<,y-bQ*(
z1{E:~f
} a6#{2q
p ?Ij-uo"o
WcZo+r
/* *tbpFk4/
**FileAccess.java x 1%J1?Fp
*//文件访问(定位，写) >tXufzW
package NetFox; &dwI8@&
import java.io.*; ~q'w),bE"Q
t9$AvE#a!=
*1ID`o
public class FileAccessI implements Serializable{ Ul7pxzj
@> +^<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pZ@W6}
RandomAccessFile oSavedFile; /`j K
long nPos; eK=m02
W=;(t
YN5OuKMUd'
public FileAccessI() throws IOException )LMBxyS
{ f/IRO33
this("",0); =@ L5
} 'EH
Gg3?2h"d
0?&aV_:;X
public FileAccessI(String sName,long nPos) throws IOException a\[fC=]r:
{ mNBpb}
oSavedFile = new RandomAccessFile(sName,"rw"); p)[BB6E
this.nPos = nPos; "$,}|T?Y`
oSavedFile.seek(nPos); NBbY## w0
} @tjZvRtZ
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)z*$`?)k
public synchronized int write(byte[] b,int nStart,int nLen) 7Y @=x#
{ 9rf|r 3
int n = -1; )@lo ';\
try{ $S)e"Po~5
oSavedFile.write(b,nStart,nLen); qhn&;{{
n = nLen; kw-Kx4 )
} ]~g|SqPA@
catch(IOException e) =aCIaL&9Y
{ 00.iMmJ
e.printStackTrace (); YiI:uG!|D
} v&CO#vK5.
b3 %&
,mE]?XyO
return n; G(Idiw#WT
} pRk'GR]`
r/s&ee
|V~(mS747:
} 7,&]1+n
Lct+cKKU
6_`eTL=G
/* qS/71Kv'
**SiteInfoBean.java ?+}E
*/ GD6'R"tJ
package NetFox; <g|nmu)o$
w4<u@L
qdkTg:QJ,
public class SiteInfoBean { M;Mdz[Q
ETH#IM8J
sJYKt
private String sSiteURL; //Site's URL 0or6_y6
private String sFilePath; //Saved File's Path h?pGw1Q
private String sFileName; //Saved File's Name 1WA""yb
private int nSplitter; //Count of Splited Downloading File )>#<S0>'j
RAx]Sp Q-S
r^o}Y
public SiteInfoBean() \Dsl7s=
{//nSplitter的缺省值为5 as!|8JE`
//default value of nSplitter is 5 I`n1M+=%
this("","","",5); +IOKE\,Y
} `v/tf|v6
eQ)ioY
[9W&1zY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "*>QxA%c4
{ k9VQ6A
sSiteURL= sURL; 0wE8GmG
sFilePath = sPath; cdU >iB,
sFileName = sName; N(({2'Rr
this.nSplitter = nSpiltter; r{:la56Xd
0\ytBxL
)*L?PT
} cX=b q_
Dil4ut-$
dU04/]modD
public String getSSiteURL() [Xo J7
{ gu.))3D9
return sSiteURL; &MGgO\|6
} Z`1o#yZ
}-]s#^'w
;uo|4?E:\(
public void setSSiteURL(String value) WZO 0u
{ +P6
sSiteURL = value; m5Laq'~0_
} ,vY I O
u #QSa$P
[?r\b
public String getSFilePath() 1MzB?[gx
{ eEds-&_
return sFilePath; WE8L?55_Au
} Z(`K6`KM
&)'kX
'`A67bdq)
public void setSFilePath(String value) K/LaA4
{ Fb4S/_ V
sFilePath = value; -){^ Q:u
} oIR%{`3"I
PT*@#:MA
+z/73s0~
public String getSFileName() [(^''*7r+T
{ $/(/v?3][e
return sFileName; E6IL,Iq9
} *q9$SDm
kd2'-9
@P*P8v8:
public void setSFileName(String value) D `3yv R
{ R8Ei:f}
sFileName = value; Ita!07
} HQ#L |LN
ha'm`LiX
7^}Z%c
public int getNSplitter() |P?B AWYeQ
{ -`<N,
return nSplitter; X/D9%[{&
} HE.Dl7{
Qz90 mb
!{=%l+^.
public void setNSplitter(int nCount) k`zK
{ L1w4WFWO
nSplitter = nCount; o\YdL2:X
} KE1@z]
} ]tV{#iIJ*
j3'/jk]\
T//+&Sk[
/* j W]c9u
**Utility.java G!lykk]
*/ )uJ`E8>-
package NetFox; WQ`P^5e
20xGj?M
hzVr3;3Zn
public class Utility { VTkT4C@I;Y
9jFDBy+
|"&4"nwa
public Utility() Olrw>YbW
{ N@ tb^M
r,@|Snv)
t#Yh!L6>
} {.'g!{SHp
!f[N&se
//线程睡眠 3JO:n6
public static void sleep(int nSecond) \DdVMn
{ ?4dd|n
try{ d`*vJ#$>2
Thread.sleep(nSecond); ApB'O;5
} ^HKaNk<
catch(Exception e) _'v )Fy
{ V^H47O;VC
e.printStackTrace (); 9GOyVKUv
} 3Jit2W4
} Xq$0% WjG
c=mFYsSv
//日志 4h@of'
public static void log(String sMsg) g5]DA.&(
{ *\5H\s9<
System.err.println(sMsg); R5~m"bE
} 1KEPD@0oxx
[_GR'x'0x
n m$G4Q
public static void log(int sMsg) 6/C
{ J)~=b_'<
System.err.println(sMsg); g4932_tC
} D'=`O6pK
} JIkmtZv
(bXp1*0 ;
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/* F=lj$?4{
**TestMethod.java jtJU5Q
*/ Msdwv.jM
package NetFox; DGUU1vA
!S<~(Ujyw
U4/$4.'NQ
public class TestMethod { `OK }q
p`ZGV97
p#I1l2nE
public TestMethod() X> KsbOZ
{ ///xx/weblogic60b2_win.exe cE#Y,-f
try{ ucO]&'hu:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Kqjeqr@)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b?^<';,5
SiteFileFetch fileFetch = new SiteFileFetch(bean); "@Fxfd+Ot
fileFetch.start(); vdM\scO:
} uSbg*OA
catch(Exception e){e.printStackTrace ();} }gt~{9?c
,4UJ|D=J
@TT[H*,
} jV8><5C
iSax-Mc
b(,[g>xH
public static void main(String[] args) a_x6 v*
{ 9dv~WtH>5
new TestMethod(); 247>+:7z
} mI18A#[ 3
} L*38T\
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