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)); Q6I:"2u1
} n#_$\ p>Yd
for(int i=0;i<nEndPos.length-1;i++) nwCrZW
{ &W6^sj*k5U
nEndPos = nStartPos[i+1]; e6RPIg
} ] {HI?V
nEndPos[nEndPos.length-1] = nFileLength; !0mI;~q|F
} $z*'fXg
} lQkQ9##*
~zNAbaC+>t
XAL1|]S
//启动子线程 iTU5l5Uz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fkNbS
for(int i=0;i<nStartPos.length;i++) e'D&8z_;
{ @/-\k*T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,{?%m6.lE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }Y36C.@H
nStartPos,nEndPos,i); [87,s.MK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %;YHt=(1*X
fileSplitterFetch.start(); NGOfb
} 8StgsM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), = 6\^%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3"KCh\\b
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xAMW-eF?d
nEndPos = " + nFileLength); _MX>#!l
// fileSplitterFetch[nPos.length-1].start(); 2WxQ(:d=
x0w4)Ic5
j9+w#G]hV
//等待子线程结束 161xAig
//int count = 0; >]5P 3\AQV
//是否结束while循环 W#WVfr
boolean breakWhile = false; Sa;qW3dt3E
_X"N1,0
**gXvTqI
while(!bStop) o"R7,N0rB
{ LW_f
write_nPos(); ut/=R !(K
Utility.sleep(500); H-fX(9
breakWhile = true; m#Z# .j_2
!9P';p}2
m<"WDU?y;
for(int i=0;i<nStartPos.length;i++) PQ$%H>{
{ ?|B&M\}g
if(!fileSplitterFetch.bDownOver) { W{]L:
{ ptxbDzOz
breakWhile = false; e|WJQd4+S
break; yT9@!]^L
} \<TXS)w]
} &t:Gx<]
if(breakWhile) qfRH5)k
break; ILShd)]Rw
56-dD5{hxR
!.(P~j][
//count++; .rqhi
//if(count>4) 6 EC*
// siteStop(); @;?p&.W`D
} oij}'|/Jc
ly_HWuFJ3
c?&X?<
System.err.println("文件下载结束！"); e5*hE
} b:]V`uF?
catch(Exception e){e.printStackTrace ();} >!bJslWA
} FOy|F-j
8=uu8-l8g
x$Oq0d{T
//获得文件长度 kH7(@Pa
public long getFileSize() 3e;^/kf<9
{ ]B3=lc"
int nFileLength = -1; Vi]W|bP
try{ kbMWGB%;
URL url = new URL(siteInfoBean.getSSiteURL()); OO*zhGD;[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d,Yw5$i
httpConnection.setRequestProperty("User-Agent","NetFox"); P&ptJtNg
RM]M@%,K
B s#hr3h-
int responseCode=httpConnection.getResponseCode(); .|b$NM
if(responseCode>=400) K<ft2anY5
{ Ne{?:h.!
processErrorCode(responseCode); '2nhv,|.U
return -2; //-2 represent access is error *XbEiMJ
} ]<rkxgMW>
oO|KEY(
0C irfcs}Z
String sHeader; 6vNrBB
%Iv,@}kvT+
KZ ;k)O.Ov
for(int i=1;;i++) ,J^b0@S
{ "haL
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dj7hx"BI
//Utility.log(in.readLine()); 6GSI"M6s
sHeader=httpConnection.getHeaderFieldKey(i); LzXmb 7A
if(sHeader!=null) %9N7Ln|%
{ i}mVQ\j5
if(sHeader.equals("Content-Length")) RcM/!,B
{ 2Mvrey)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :f}9($
break; ,<tX%n`v=
} n;+LH9
} Hmd] FC,_
else fW3(&@
break; ,3p~w5C/+[
} 6S*exw
} > BY&,4r
catch(IOException e){e.printStackTrace ();} ()Y4v
catch(Exception e){e.printStackTrace ();} ]?+p5;{y4
y4I6
L>9V&\
Utility.log(nFileLength); w?wG(+X7
aM2l2
E2@65b$
return nFileLength; Ax?y
} v7jq@#-
D!NQ~'.a=2
I^UC&5dC
//保存下载信息（文件指针位置） o-{[|/)Tk
private void write_nPos() ,5kKimTt
{ E^lvbLh'
try{ ?_$=l1vf
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;8*`{F[
output.writeInt(nStartPos.length); q<[_T
for(int i=0;i<nStartPos.length;i++) FsV'Cu@!U
{ WD2]&g
// output.writeLong(nPos); pP?MWe Eg
output.writeLong(fileSplitterFetch.nStartPos); cc&axc7I
output.writeLong(fileSplitterFetch.nEndPos); Xg SxN!I
} v'qG26
output.close(); Co9QW/'i
} hMUs" <.
catch(IOException e){e.printStackTrace ();} GCX G/k?w:
catch(Exception e){e.printStackTrace ();} E4W -hq~
} 2FF4W54I
8:>1F,
OjF_ %5
//读取保存的下载信息（文件指针位置） u7[ykyV
private void read_nPos() 9:,\gw>F
{ |e?64%l5P
try{ 3'qJ/*]9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -/cZeQDPb
int nCount = input.readInt(); ##;Er47@^
nStartPos = new long[nCount]; 65p?Igb
nEndPos = new long[nCount]; #H{<gjs]
for(int i=0;i<nStartPos.length;i++) ( Qcp{q
{ ~ ! 3I2
nStartPos = input.readLong(); " '6;/N
nEndPos = input.readLong(); qT"Q1xU[
} Bck7\
input.close(); \"^w'ng
} 4%}*&nsI-Z
catch(IOException e){e.printStackTrace ();} mc_ch$r!
catch(Exception e){e.printStackTrace ();} Ph}|dGb
} kc @[9eV
;A'Z4=*~
2 :mn</z
private void processErrorCode(int nErrorCode) I8<,U!$
{ O.Iu6D
System.err.println("Error Code : " + nErrorCode); PSVc+s[Q+V
} `v}%33$hA
8J~1-;
!Mim@!5M
//停止文件下载 &f^l^K5:
public void siteStop() [y)`k@
{ 1Q4}'0U4
bStop = true; $Y_i4(
for(int i=0;i<nStartPos.length;i++) 1jPJw3"3h
fileSplitterFetch.splitterStop(); &S]@Ot<z
F;[T#N:~
7.@TK&
} %]6~Eq%s
} @@rEs40
//负责部分文件的抓取 ,0~9dS
**FileSplitterFetch.java :l&V]}:7*
*/ <Ib[82PU
package NetFox; vab@-=%k
tBT<EV{ G
AfP'EP0m
import java.io.*; 2aB^WY'tC
import java.net.*; $:j G-r
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$w0lrh[+
public class FileSplitterFetch extends Thread { WN5`;{\
Ck@J,~x1D
H_Kj7(=&>
String sURL; //File URL wTGbd
long nStartPos; //File Snippet Start Position *B\H-lp?
long nEndPos; //File Snippet End Position VY"9?2?/
int nThreadID; //Thread's ID Ra/Ukv_v
boolean bDownOver = false; //Downing is over RJH,
boolean bStop = false; //Stop identical .8uz 6~
FileAccessI fileAccessI = null; //File Access interface bY2 C]r(n
xD /9F18
?N=m<fn
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Cb@3M"1:
{ 1q3( @D5~+
this.sURL = sURL; R:AA,^Z
this.nStartPos = nStart; *"98L+
this.nEndPos = nEnd; >,gvb5
nThreadID = id; =rQP[ICs!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7Wa?$6d
} { "xln/
o|iYd n\
zrv#Xa!O\
public void run() d90Z,nex
{ st&
while(nStartPos < nEndPos && !bStop) k@D0 {z
{ 8W+gl=C~
d:q +
TLf9>= OVh
try{ !W'Ui 9uX
URL url = new URL(sURL); ai^4'{#zi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [;.`,/
httpConnection.setRequestProperty("User-Agent","NetFox"); N+)?$[
String sProperty = "bytes="+nStartPos+"-"; (ihP`k-.
httpConnection.setRequestProperty("RANGE",sProperty); X$\i{p9jw
Utility.log(sProperty); Dbaf0
ow;R$5G
*P!e:Tm)
InputStream input = httpConnection.getInputStream(); 3!o4)yJWx
//logResponseHead(httpConnection); $RwB_F
oi&Wo'DX
&Q=ZwC7#
byte[] b = new byte[1024]; omf Rs
int nRead; cZ+7.oDu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yag}fQ(XH
{ GOB(#vu
nStartPos += fileAccessI.write(b,0,nRead); 4Kv[e]10(
//if(nThreadID == 1) F;!2(sPS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '[(nmx'yVJ
} Q2%QLM:.,
\#x}q'BC4
@l(vYJ:f
Utility.log("Thread " + nThreadID + " is over!"); %_aMl
bDownOver = true; ixh47M
//nPos = fileAccessI.write (b,0,nRead); QIn/,Yd
} /<3<. ~
catch(Exception e){e.printStackTrace ();} |m?vVLq
} _0 snAt^iC
} sK=}E=
Pe~`16f
9kY[j2,+
//打印回应的头信息 8?Y['
public void logResponseHead(HttpURLConnection con) ])#\_'fg
{ UU}7U]9u
for(int i=1;;i++) &Rz, J]
{ I#FF*@oeM
String header=con.getHeaderFieldKey(i); |\uYv|sT
if(header!=null) dYojm1MQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D~&Mwsi
Utility.log(header+" : "+con.getHeaderField(header)); }GnwY97
else qJT0Y/l:(
break; 7TX,T|>9
} w.+Eyu_I\
} 7yiJ1K<bIt
-#A:`/22
c;I, O
public void splitterStop() +MO E
{ tllBCuAe
bStop = true; I/COqU7~
} 9;r? nZT/
g42R 'E%
|AH@ EI>
} 22KI]$D#f
jV7&Y.$zF]
>n7["7HHk
/* z]$j7dp
**FileAccess.java vh>{_ #
*//文件访问(定位，写) DcV<y-`'1
package NetFox; fjDpwb:x)
import java.io.*; /k"hH\Pp
K{}4zuZ
"t&{yBQ0u
public class FileAccessI implements Serializable{ /k7wwZiY@
dNVv4{S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JAn1{<Ky
RandomAccessFile oSavedFile; C'9 1d7E
long nPos; LEc8NQs
bEr.nF
s5Fr)q// !
public FileAccessI() throws IOException FyEDt@J
{ %N~CvN@T
this("",0); R~B0+:6
} udTxNl!
6|;0ax4:P
`f'C[a"
public FileAccessI(String sName,long nPos) throws IOException fEu9Jk
{ +>3]%i-\
oSavedFile = new RandomAccessFile(sName,"rw"); 5&4F,v[zp
this.nPos = nPos; yCM{M
oSavedFile.seek(nPos); <~%t$:
} cq^sq1A:
Z[,`"}}hv=
Yn[x #DS
public synchronized int write(byte[] b,int nStart,int nLen) 4IGxI7~27#
{ B {i&~k
int n = -1; '}O!2W&Y]%
try{ 2uo8jF.h
oSavedFile.write(b,nStart,nLen); YbvX$/zGu
n = nLen; 5|WOBOh>`&
} [w%#<5h
catch(IOException e) W:ixzpQ
{ pa] TeH
e.printStackTrace (); -v*x V;[
} \FI^Vk
^~I @ spR4
X"J%R/f
return n; _XN~@5elrC
} s}b*5@8|tA
G(i\'#5+
._BB+G
} H*qD: N
Fi{mr*}
T^.{9F]*S
/* ag/u8
**SiteInfoBean.java WB"$u2{|i
*/ 'o8\`\'H!
package NetFox; Gt.*_E
|7S:l9;
F9D"kG;Dk
public class SiteInfoBean { xhD$e= g
w})NmaT;YF
`hF;$
private String sSiteURL; //Site's URL g Np-f
private String sFilePath; //Saved File's Path \R;K>c7=
private String sFileName; //Saved File's Name @5*xw1B
private int nSplitter; //Count of Splited Downloading File uk{J@&F
3&'R1~Vh
ks^|>
public SiteInfoBean() 9_`3IJ
{//nSplitter的缺省值为5 |x[$3R1@
//default value of nSplitter is 5 NFM-)Z57
this("","","",5); Pb=rFas*C
} [b pwg&Oo
0kz7 >v
f8F1~q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "x.88,T6
{ ?ZM^%]/+
sSiteURL= sURL; Kk56/(_S
sFilePath = sPath; kBUufV~
sFileName = sName; [EcV\.
this.nSplitter = nSpiltter; I]UA0[8X
Suj}MEiv
)muv;Rf`e5
} nvwDx*[qN
|7Yvq%E
7vdHR\#;$
public String getSSiteURL() T7X!#j"\
{ hG[4O3jo\
return sSiteURL; FL~9</
} )uuwwz
xP{m9_Qj
KXDz'9_
public void setSSiteURL(String value) JiUT\y
{ dnLo(<{<U
sSiteURL = value; DD)mN) &T
} IFkvv1S`
?RqTbT@~
aq$62>[
public String getSFilePath() lP-kZA!
{ gx&\Kw6HM
return sFilePath; FW5*_%J
} P|yGx)'^P
)OS>9 kFH
{m>~`
public void setSFilePath(String value) CrT2#h 1#
{ /6A:J]Q_
sFilePath = value; CD$u=E ]
} p}cd}@cQ6
DPR;$yV
`8qT['`#R
public String getSFileName() |A2W8b {]
{ =t~+63)
return sFileName; Kn3YI9
} $&c<T4$d
#xD&z^o
Jq=X!mTd.
public void setSFileName(String value) A;b=E[iv
{ `,hW;p>-
sFileName = value; ~k"eEV p
} {.0X[uAf
&T5fH!?4
JsHxQ0Tw
public int getNSplitter() {IF}d*:
{ [w+yQ7P
return nSplitter; & bp#1KR)
} ~pDRF(
m1M;'tT@
u-]vK
public void setNSplitter(int nCount) 8T!fGzHx
{ $4#=#aKW.
nSplitter = nCount; <yPq;#z(!
} - I1cAt
} 5e~ j
Ac*B[ywA3
^\Ue7,H-
/* 3Qm t]q
**Utility.java q!ulE{ ^
*/ ir( -$*J
package NetFox; mgJ]@s}9
{66Q" H"I
c%6 @ z
public class Utility { BWqik_
%B*<BgJ;4F
gdkLPZ<<
public Utility() ySPlyhGF
{ WOe{mwhhj
24.7S LXO
<s59OdzP
} fwar8 i1
C.Wms}XA
//线程睡眠 i`ZHjW~`
public static void sleep(int nSecond) ?[NTw./'7A
{ QI :/,w
try{ mfp`Iy"}+
Thread.sleep(nSecond); M+;!]tbc3
} BIHHRCe:@n
catch(Exception e) 0k.#
{ tDuUAI54
e.printStackTrace (); TA-(_jm
} 7><* 9iOW
} Ot4;,UZ
P_^|KEz
//日志 8E.5k@
public static void log(String sMsg) o0-fUCmC
{ |P[D2R}
System.err.println(sMsg); =%#$HQ=
} b'Piymx
w;h\Y+Myyk
eaZ)1od
public static void log(int sMsg) 1z$}*`
{ Jte:l:yjtA
System.err.println(sMsg); hBYh90]
} {XVf|zM,
} !m/Dd0
L2V $%*6
\8@[bpI@g
/* :n%sU*'T
**TestMethod.java !_/8!95
*/ VES4x%r=
package NetFox; ;29XvhS8
<EMLiiNY
v#YS`];B
public class TestMethod { q[,R%6&'
`'WY'\|C
6jy n,GU
public TestMethod() +ke42Jwt
{ ///xx/weblogic60b2_win.exe lDX&v$
try{ lLwQridFXh
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <=GzK:4L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `sp'Cl!
SiteFileFetch fileFetch = new SiteFileFetch(bean); J9KLO=
fileFetch.start(); :QhEu%e
} D*2p
catch(Exception e){e.printStackTrace ();} dxhjPS~^Q
]&tr\-3
uD*s^
} v%PWr5]
}rAN2D]"}
i!+3uHWu`)
public static void main(String[] args) (A<sFw?
{ Qd)cFL"v
new TestMethod(); HBf8!\0|/
} `] dx%
} \5pAG mgD
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