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)); 4_+Pv6
} K//T}-Uub
for(int i=0;i<nEndPos.length-1;i++) -kbm$~P
{ }4SSo)Uv/
nEndPos = nStartPos[i+1]; @@83PJFid
} _wNPA1q0J
nEndPos[nEndPos.length-1] = nFileLength; b`W*vduf
} LUck>l\l
} wy{>gvqK
Z=@)
6 ]Oxx{|}
//启动子线程 toqzS!&.v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .dT;T%3fO
for(int i=0;i<nStartPos.length;i++) xGfDz*t
{ p{q!jm~Nq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4q13xX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U5!f++
nStartPos,nEndPos,i); W@,p9=425
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KC:4
fileSplitterFetch.start(); YX`=M
} *Ca)RgM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JA(fam~{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); RX5.bVp eE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UZP6x2:=
nEndPos = " + nFileLength); _i[)$EgFm
// fileSplitterFetch[nPos.length-1].start(); -'[(Uzj
Wi[m`#
:z.Y$]F@
//等待子线程结束 drKjLo[y
//int count = 0; 9xn23*Fo
//是否结束while循环 ceZ8}Sh
boolean breakWhile = false; UVc<C 1q
^}Qj}
N4mJU'_{
while(!bStop) s;2/Nc
{ +'/}[1q1/T
write_nPos(); (\t_Hs::a
Utility.sleep(500); ZuvPDW%
breakWhile = true; V.ji _vX
Hpi%9SAM
`n`"g<K)Q
for(int i=0;i<nStartPos.length;i++) eQFb$C]R}y
{ 7TkxvSL X
if(!fileSplitterFetch.bDownOver) ^mueFw}\
{ ;Q=GJ5`B
breakWhile = false; {Mr~%y4
break; }l(m5
} i9eyrl+!
} u'i%~(:$\)
if(breakWhile) LkGf|yd_
break; F|?'9s*;6G
:e]9T3Q
j;20JA/b
//count++; 0[:9 Hb6
//if(count>4) ,.jHV
// siteStop(); 7grt4k
} ~r^5-\[hZ
MJ*]fC3/
hiRR+`L%
System.err.println("文件下载结束！"); cZr G:\A
} hyb +#R
catch(Exception e){e.printStackTrace ();} Q"|kW[Sg
} $iqi:vY
%gu$_S
Ji6`-~ k
//获得文件长度 ;wXY3|@
public long getFileSize() g TXW2S
{ )W]>\=@Y
int nFileLength = -1; N pXgyD
try{ }B"|z'u
URL url = new URL(siteInfoBean.getSSiteURL()); _t|G@D{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +Cf0Y2*@hM
httpConnection.setRequestProperty("User-Agent","NetFox"); e" Eqi-
qsihQd
/&$"}Z6z
int responseCode=httpConnection.getResponseCode(); TTZ['HP oI
if(responseCode>=400) wI! +L&Q
{ t0e{|du
processErrorCode(responseCode); ^+*GbY$'
return -2; //-2 represent access is error hB?,7-
} VJN/#
x^)g'16`
^p 2.UW
String sHeader; `u#;MUg
2"leUur~rO
EK?@Z.q+
for(int i=1;;i++) G;C8Kde
{ OG`|td
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); goDV2alC^
//Utility.log(in.readLine()); 4L=$K2R2r
sHeader=httpConnection.getHeaderFieldKey(i); Dc.n-ipv$
if(sHeader!=null) u3Usq=Ij{
{ +_ *eu
if(sHeader.equals("Content-Length")) QSHJmk 6L
{ V)0[`zJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s]y-pZ
break; t/KcXM
} Ak5[PBbW
} 5=Kq@[(4
else C}mYt/
break; <rX\LwR
} =6cyE
} -(\1r2 Y
catch(IOException e){e.printStackTrace ();} HKTeqH_:
catch(Exception e){e.printStackTrace ();} [x!i* rW3
^^7L"je]g
euV$2Fg
Utility.log(nFileLength); qr)v'aC3
<.,RBo
L#`2.nU
return nFileLength; EI1W .V>@
} ;w`sz.
*A?8F"6>
5LQk8NPh
//保存下载信息（文件指针位置） JFkN=YR8
private void write_nPos() WI1T?.Gc
{ (9mbF%b
try{ {I0w`xe
output = new DataOutputStream(new FileOutputStream(tmpFile)); :`0'GM" `
output.writeInt(nStartPos.length); l`@0zw+
for(int i=0;i<nStartPos.length;i++) oL<BLr9>
{ {y,nFxLq
// output.writeLong(nPos); {Q5KV%F_
output.writeLong(fileSplitterFetch.nStartPos); q&zny2])
output.writeLong(fileSplitterFetch.nEndPos); J>`v.8y
} WD15pq l
output.close(); iH-bo@
} o]Z _@VI
catch(IOException e){e.printStackTrace ();} Hf VHI1f
catch(Exception e){e.printStackTrace ();} t< sp%zXZ
} w&p~0cA~
_*s~`jn{H
NWEhAj<w
//读取保存的下载信息（文件指针位置） UT3bd,,
private void read_nPos() +J|+es
{ i[$-_
try{ ]SFWt/<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pw@`}cM=
int nCount = input.readInt(); ]\A1mw-T
nStartPos = new long[nCount]; i=oTg
nEndPos = new long[nCount]; _ XE;-weE
for(int i=0;i<nStartPos.length;i++) `-VG ?J
{ XZ.7c{B<
nStartPos = input.readLong(); wJ6_I$>
nEndPos = input.readLong(); B!eK!B
} oJ^C]E
input.close(); 1p8:.1)q
} kMM'[w
catch(IOException e){e.printStackTrace ();} jcE Msc
catch(Exception e){e.printStackTrace ();} wGg0hL
} }FrEF\}]_7
:'Zx{F`
3 m6$YWO
private void processErrorCode(int nErrorCode) c$9sF@K?
{ d]U`?A,
System.err.println("Error Code : " + nErrorCode); ~?gzq~~t
} 6N"m?g*Z d
K[kds`
Q4RpK(N
//停止文件下载 k@S)j<
public void siteStop() '=VH6@vZ_'
{ >tN5vWW
bStop = true; wHf&R3fg
for(int i=0;i<nStartPos.length;i++) %NNj9Bl<VV
fileSplitterFetch.splitterStop(); DKX/W+#a
W3)\co
IXnb]q.
} TN5>"??"
} oz LH]*
//负责部分文件的抓取 +jUgx;u,
**FileSplitterFetch.java FC{})|yh }
*/ a0PE^U
package NetFox; t<Ot|Ex
xk& NAB
<Z},A-\S*
import java.io.*; _6ZzuVv3/
import java.net.*; +p9- .YM
.46#`4av
vv+km+
public class FileSplitterFetch extends Thread { 7'z(~3D
P>(&glr|
;`DD}j`
String sURL; //File URL Xh?4mKgu
long nStartPos; //File Snippet Start Position 0LdJZP
long nEndPos; //File Snippet End Position F>*{e
int nThreadID; //Thread's ID +~N!9eMc
boolean bDownOver = false; //Downing is over e!GZSk
boolean bStop = false; //Stop identical YxXqI
FileAccessI fileAccessI = null; //File Access interface Goxl3LS<
HmMO*k<6@
! D$Ooamq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1RLym9JN
{ `{[RjM`
this.sURL = sURL; u"`*DFjo*
this.nStartPos = nStart; *7ZtNo[+
this.nEndPos = nEnd; #.H}r6jqs
nThreadID = id; X3<K 1/<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P;73Hr[E#
} \8{\;L C
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=>qTNh*'
public void run() A{N\)
{ M diwRi
while(nStartPos < nEndPos && !bStop) b?8)7.{F{
{ 4ZwKpQ6
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^*0'\/N&
try{ <`)iA-Df;9
URL url = new URL(sURL); 96c?3ya
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {L].T#
httpConnection.setRequestProperty("User-Agent","NetFox"); rh66_eV
String sProperty = "bytes="+nStartPos+"-"; E;9>ePd@
httpConnection.setRequestProperty("RANGE",sProperty); k[%aCGo
Utility.log(sProperty); lNz]HiD
4jX3lq|
x:fW~!Xc6
InputStream input = httpConnection.getInputStream(); 7CGyC[[T~
//logResponseHead(httpConnection); z8"7u/4v{
FQk!d$BG
?{6s58Q{
byte[] b = new byte[1024]; I`T1Pll
int nRead; i7w(S3a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Qs%B'9")
{ B2Z_]q$n*
nStartPos += fileAccessI.write(b,0,nRead); .XS9,/S
//if(nThreadID == 1) MLr-, "gs
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y1)!lTG
} nls
wP<07t[-g
z=g$Exl
Utility.log("Thread " + nThreadID + " is over!"); }gv8au<
bDownOver = true; W3GNA""O
//nPos = fileAccessI.write (b,0,nRead); du_4eB
} G69GoT
catch(Exception e){e.printStackTrace ();} XogVpkA
} MjD75hIZ
} l$XPIC~H
3TS_-l
XKS8K4"
//打印回应的头信息 2'] KTHm
public void logResponseHead(HttpURLConnection con) <CZgQ\Mt
{ , jU5|2
for(int i=1;;i++) e2cP *J
{ 6;iJ*2f5V
String header=con.getHeaderFieldKey(i); `XKVr
if(header!=null) l1'6cLT`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3I $>uR
Utility.log(header+" : "+con.getHeaderField(header)); 9t$]X>}
else %%JMb=!%2
break; tU:EN;H
} ,R2U`EO;
} G8J*Wnwu[K
[0y$! f4
E\U`2{^.
public void splitterStop() />44]A<
{ ,|h)bg7.
bStop = true; 2VGg 6%
} U*)m',
oD.r`]k
_S`o1^Ad
} CU)|-*uiK
2=iH$v
C\*4q8(
/* ,xfO;yd
**FileAccess.java 8gy_Yj&{P
*//文件访问(定位，写) gckI.[!b
package NetFox; IzLQhDJ1
import java.io.*; y[?-@7i
qfoD
p B;3bc
public class FileAccessI implements Serializable{ OI}cs2m
&(N+.T5cp
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )B$;Vs]@i
RandomAccessFile oSavedFile; = ieag7!
long nPos; ~j9O$s~)
$I9qgDJ)
&--ej|n
public FileAccessI() throws IOException )#iq4@)|g
{ bm% $86
this("",0); cyM-)r@YQV
} jMNU ?m:
[7FItlF%I
%w7pkh,
public FileAccessI(String sName,long nPos) throws IOException |r%D\EB
{ OEx^3z^
oSavedFile = new RandomAccessFile(sName,"rw"); eKvV*[Na
this.nPos = nPos; cLVeT
oSavedFile.seek(nPos); :'iYxhM.V
} =#gEB#$x:
wU\s; dK
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public synchronized int write(byte[] b,int nStart,int nLen) QPtGdd
{ }g7]?Ee
int n = -1; n\z,/'d"
try{ Z|"p*5O,
oSavedFile.write(b,nStart,nLen); j _L@U2i
n = nLen; wV\gj~U;P
} T"7~AbgNU
catch(IOException e) $(e#aHB
{ X;v$5UKU
e.printStackTrace (); '6y}ZE[
} MY#
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GVHV =E
return n; ^z6_Uw[
} >K9#3 4hP
4;`oUt'.
V'*~L\;pU
} !`41q=r
l>*"mh
y\dEk:\)
/* %\|'%/"`2(
**SiteInfoBean.java @c9^q>Uv
*/ R218(8S
package NetFox; B/~%h|
xj5;: g#!
YW u cvw&
public class SiteInfoBean { 4lhw3,5
@Z>ZiU,^
I$N8tn+E
private String sSiteURL; //Site's URL t58e(dgi
private String sFilePath; //Saved File's Path )9l^O
private String sFileName; //Saved File's Name !l]dR@e
private int nSplitter; //Count of Splited Downloading File Wjhvxk
&nBa=Enf
AdRX`[ik
public SiteInfoBean() <\kr1qHH
{//nSplitter的缺省值为5 iu&wO<)+?
//default value of nSplitter is 5 AKMm&(fh%
this("","","",5); ^P151*=D
} oF(Lji?m
;qHOOT
`W/sP\3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ok|qyN+
{ r{l(O,|e
sSiteURL= sURL; pvmC$n^zc
sFilePath = sPath; F1L:,.e`
sFileName = sName; a:QDBS2Llv
this.nSplitter = nSpiltter; Uf}\p~;
x#Sqn#
P ;IrBq6|o
} y WV#Up
AL>$HB$
qOIW(D
public String getSSiteURL() q.,JVGMS
{ 23~Sjr
return sSiteURL; Xy5e5K
} 8Q_SRwN
8\:NMP8W\
p<M\U"5Ye
public void setSSiteURL(String value) Y>'|oygHA
{ cM&{+el
sSiteURL = value; E[Cb|E
} EkziAON
jH_JmYd
BcI|:qv|
public String getSFilePath() xyI}y(CN1
{ /7gOSwY
return sFilePath; q$=#A7H>3)
} (<^yqH?
w*R$o
XQw>EZdj_N
public void setSFilePath(String value) L|p Z$HB
{ Ol!ntNhXm
sFilePath = value; _%QhOY5tv"
} 6Fe34n]m
}iuWAFZbGS
j_Yp>=+[
public String getSFileName() I_RsYw
{ qgfi\/$6
return sFileName; o}ZdTf=
} YpqrZWvh
=ZqT3_
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public void setSFileName(String value) ti#7(^j
{ -\C!I
sFileName = value; i-6Z"b{
} ~c\e'&sc;
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public int getNSplitter() ?!+MM&c-n
{ rW=Z>1
return nSplitter; AJ=qna
} ?"g!
+llR204
!jTcsN%
public void setNSplitter(int nCount) Y=Kc'x[,Zj
{ "men
nSplitter = nCount; &G-!qxe
} .X;3,D[w
} /{&tY:;m
bD?VU<)3
_ jsK}- \
/* .hifsB~
**Utility.java Om5Y|v"*
*/ s=;uc]9g
package NetFox; u?}(P_9
n^g|Ja
ynQ: >tw
public class Utility { P09;ng67
Hg=";,J
xU4 +|d
public Utility() z*!%g[3I
{ I"A_b}~*}
/#)/;
xsD($_
} j-lfMEa$o
s6@DGSJ
//线程睡眠 ATK_DEAu
public static void sleep(int nSecond) 6}FP
{ Jt}Bpg!J
try{ 85LAYaw
Thread.sleep(nSecond); z62;cv
} j3{D^|0bP
catch(Exception e) C@'h<[v`1v
{ N u<_}
e.printStackTrace (); $adbCY\
} 6V7B;tB
} )!P)U(*v
T[g[&K1Y
//日志 5?]hd*8
public static void log(String sMsg) T9Nb`sbV]
{ K/|Z$4S
System.err.println(sMsg); x$6^R q>2
} vzim<;i
E2Q[ZoVS
!1$])VQWI
public static void log(int sMsg) ,X`)ct
{ .K1FKC$C
System.err.println(sMsg); 8@MV%MVy$
} M`,)wi
} OCBgR4I
JzQ)jdvp
+%ee8|\
/* |#]@Z)xa
**TestMethod.java R#%(5-Zu#R
*/ iKX-myCz
package NetFox; < HVl(O
v|dBSX9k0
H|3:6x
public class TestMethod { LG9+y
W*Zkc:{eB
onz?_SAW
public TestMethod() JB<Sl4
{ ///xx/weblogic60b2_win.exe 0jy2H2
try{ <G|(|E1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _Xk.p_uh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A%KDiIA
SiteFileFetch fileFetch = new SiteFileFetch(bean); A kC1z73<
fileFetch.start(); I|gB@|_~
} }`%*W`9b
catch(Exception e){e.printStackTrace ();} 4T|b Cs?e
,JAx ?Xb
^c-
} cW@Zd5&0S
-GhP9; d
v+46QK|I&
public static void main(String[] args) hI]Hp3S
{ MQ5R O;RY
new TestMethod(); ;oW6 NJ
} e7Xeo+/
} Pg,b-W?n*
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