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)); \N)!]jq
} cs)R8vuB)z
for(int i=0;i<nEndPos.length-1;i++) qDjH^f
{ -hZw.eChQa
nEndPos = nStartPos[i+1]; ;rt\
} Y|-:z@n6C
nEndPos[nEndPos.length-1] = nFileLength; |uM(A~?
} K,Hxe;-
} ,gIeQ!+vy
OwLJS5r@<-
@[j%V ynf
//启动子线程 C0H@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -;GB Xq
for(int i=0;i<nStartPos.length;i++) )T'~F
{ mJME1#j$/|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =Kt!+^\")
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;tfGhHpQn
nStartPos,nEndPos,i); ^'4I%L"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d@{#F"o
fileSplitterFetch.start(); ]NY^0SqM
} N`7+]T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /n3SE0Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); P7;q^jlB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BJnysQ
nEndPos = " + nFileLength); t[\6/`YH
// fileSplitterFetch[nPos.length-1].start(); rz5@E
PH=O>a`a_O
JgcMk]|'
//等待子线程结束 c)SQ@B@q
//int count = 0; Q,R|VI6Co
//是否结束while循环 d@ tD0s
boolean breakWhile = false; 1c:/c|shQ_
/B5rWJ2AS
2o~UA\:+=
while(!bStop) e(jD[q
{ L+0O=zJF
write_nPos(); z#+Sf.
Utility.sleep(500); 9oVprd>%@
breakWhile = true; pB,l t6
gflO0$i
p I@!2c:}
for(int i=0;i<nStartPos.length;i++) h BzZJ/jn
{ ! Y'~?BI
if(!fileSplitterFetch.bDownOver) 6' 9zpe@`
{ (b+o$C
breakWhile = false; D1cnf"y^
break; *.+N?%sAP)
} jgT *=/GH2
} #x(3>}
if(breakWhile) ]9hhAT44
break; k<%y+v
(^^}Ke{J
oC(.u?
//count++; 4J$dG l#f
//if(count>4) lt#3&@<v
// siteStop(); <Mf(2`T
} ^PowL:
}*vO&J@z
g>_d,#F
System.err.println("文件下载结束！"); x24&mWgU
} H@`lM~T[
catch(Exception e){e.printStackTrace ();} pYX!l:hk
} b&.3uls6
EKzYL#(i
i [6oqZ
//获得文件长度 8lF:70wia
public long getFileSize() ^\3z$ntF
{ 5>rjL;
int nFileLength = -1; ;%O>=m'4
try{ r&nEM6
URL url = new URL(siteInfoBean.getSSiteURL()); 6o]>lQ}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \`8?=_ST
httpConnection.setRequestProperty("User-Agent","NetFox"); 5hp)Z7
JiRfLB
u{|^5%)
int responseCode=httpConnection.getResponseCode(); QVWUm!
if(responseCode>=400) d&%}u1 .
{ 0Yfz?:e
processErrorCode(responseCode); #=I5_u
return -2; //-2 represent access is error XF99h&;9
} +=(@=PJ6
}*56DX
-FQS5Zb.!
String sHeader; poXT)2^)
MMf_
Io<L! =>
for(int i=1;;i++) tj[-|h
{ ,w7ZsI4:[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); d6~d)E
//Utility.log(in.readLine()); H;RgYu2J
sHeader=httpConnection.getHeaderFieldKey(i); t&rr;W]
if(sHeader!=null) i&JI"Dd7
{ k]yv#Pa
if(sHeader.equals("Content-Length")) _sIr'sR~
{ <}1GYeP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]}nX$xy
break; (z X&feq
} C<N7zMwT
} YG>6;g)Zm
else 0<]]q[pr
break; :A`jRe.
} =}[m_rp&
} wO"ezQ
catch(IOException e){e.printStackTrace ();} yeN(_t2.
catch(Exception e){e.printStackTrace ();} #,rP1#?
8PvO_Gz5
u1/q8'RW
Utility.log(nFileLength); 420cbD3a
vXibg
wKAxUPzm
return nFileLength; qX*Xo[Xp
} ;Dc\[r
mH!\]fmR~
)|<g\>/
//保存下载信息（文件指针位置） 10$:^
private void write_nPos() BHZSc(-o
{ I7jIA>ZZi
try{ ^tl&FWF
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1:Xg&4s
output.writeInt(nStartPos.length); !4mAZF b
for(int i=0;i<nStartPos.length;i++) bE2{^5iG
{ A9M/n^61
// output.writeLong(nPos); RJLhR_t7n
output.writeLong(fileSplitterFetch.nStartPos); #oEq)Vq>g|
output.writeLong(fileSplitterFetch.nEndPos); (eO_]<wmky
} q4ej7T8
output.close(); H]>7IhJ
} e[t1V/ah
catch(IOException e){e.printStackTrace ();} EtA,ow
catch(Exception e){e.printStackTrace ();} <`*v/D7\02
} U<U?&hB\@
1DM$FG_Z-
^%Fn|U\u
//读取保存的下载信息（文件指针位置） 7dXh,sD
private void read_nPos() zM<yd#`yt8
{ n_-k <3
try{ R!7a;J}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pOIfKd
int nCount = input.readInt(); P%Wl`NA P
nStartPos = new long[nCount]; 3vF-SgCV
nEndPos = new long[nCount]; " {Nw K
for(int i=0;i<nStartPos.length;i++) =N{-lyr)
{ H9rZWc"*
nStartPos = input.readLong(); L'}^Av_+
nEndPos = input.readLong(); mW @Z1Plxs
} rcG-Vf@
input.close(); RX\@fmK&
} B-aJn8>/
catch(IOException e){e.printStackTrace ();} E0"DHjR
catch(Exception e){e.printStackTrace ();} Xe\,:~
} -.hH,zm
j%E9@#
dV+GWJNNE
private void processErrorCode(int nErrorCode) W^dRA xVX
{ (JeRJ4
System.err.println("Error Code : " + nErrorCode); _ +A$6l
} jX 6+~
q<?r5H5
T!gq Z
//停止文件下载 %{^kmlO
public void siteStop() d15E$?ZLH
{ Y# ?M%I%j
bStop = true; v*EErQML8b
for(int i=0;i<nStartPos.length;i++) _@ @"'
fileSplitterFetch.splitterStop(); KS(Ms*k;'
Zj2tQ}N
4L[-[{2
} v@ OM
} 9NcC.}#-5
//负责部分文件的抓取 yy$7{9!
**FileSplitterFetch.java *(]@T@yN
*/ ,Y2){8#l
package NetFox; >`+-Yi$(\
407;M%?'A
T|lyjX$Q]9
import java.io.*; h*?/[XY
import java.net.*; t^@4n&Dg
K9f7,/
%TRH,-@3h
public class FileSplitterFetch extends Thread { n"Q fW~U
%#b+ =J
^tFgkzXm
String sURL; //File URL `PvGfmYOl
long nStartPos; //File Snippet Start Position T1pMe{
long nEndPos; //File Snippet End Position }8&L?B;90
int nThreadID; //Thread's ID O8S"B6?$~'
boolean bDownOver = false; //Downing is over 'C|yUsBC
boolean bStop = false; //Stop identical a+{95"4
FileAccessI fileAccessI = null; //File Access interface H1g"09?h6o
U0%m*i
0qMf6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OgBZoTT
{ E[E[Za^Y
this.sURL = sURL; |p{FSS
this.nStartPos = nStart; \.jT"Z~
this.nEndPos = nEnd; B|n<{g[-cM
nThreadID = id; /-jk_8@a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @^93q
} KmlpB
FR@##i$
xT1{O`
public void run() p&ml$N9fd
{ v_Y'o _
while(nStartPos < nEndPos && !bStop) 4>xv7
{ WgQ6EV`
-QUvd1S40
[XP3
try{ rnCu=n
URL url = new URL(sURL); cYMlcwS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :N([s(}!$2
httpConnection.setRequestProperty("User-Agent","NetFox"); 7A[`%.!F6
String sProperty = "bytes="+nStartPos+"-"; Bn_@R`
httpConnection.setRequestProperty("RANGE",sProperty); _jCjq
Utility.log(sProperty); +A,t9 3:k
L(!mm
^atBf![
InputStream input = httpConnection.getInputStream(); :X;AmLf`2u
//logResponseHead(httpConnection); /IN/SZx
sd~T
RW. >;|m
byte[] b = new byte[1024]; /K]<7
int nRead; -N[Q*;h|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7T3ub3\
{ +#!! 'XP
nStartPos += fileAccessI.write(b,0,nRead); BnLWC
//if(nThreadID == 1) W8 m*co
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); saaN$tU7
} A_WtmG_9
*FT )`
bqDHLoB\1
Utility.log("Thread " + nThreadID + " is over!"); "m:4e`_dz
bDownOver = true; D*R49hja{
//nPos = fileAccessI.write (b,0,nRead); tgbr/eCoU
} zbDM+;
catch(Exception e){e.printStackTrace ();} ' Z}/3 dp
} Dj9).lgc
} q={\|j$X
]}&f<X
T=QV =21qn
//打印回应的头信息 =pP0dvn
public void logResponseHead(HttpURLConnection con) s~(iB{-
{ @gZ<!g/vza
for(int i=1;;i++) CS*wvn;.
{ ;9R;D,Gk!
String header=con.getHeaderFieldKey(i); Jh'\ nDz@e
if(header!=null) Fhn=}7|4q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B)M& FO
Utility.log(header+" : "+con.getHeaderField(header)); Ysk,9MR(F
else WwF4`kxT
break; eY1$smh t
} HwH Wi
} 5/O;&[lYy
?X.MKNbp
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public void splitterStop() bNG;`VZ%
{ &&;ol}W
bStop = true; ]'F{uDm[
} 5Go&+|cvJ
}bVWV0Aeim
oiq7I@Y`x
} -/.Xf<y58
ji[O?
I%NPc4p
/* |6pNe T[
**FileAccess.java ec4jiE
*//文件访问(定位，写) 7lvUIc?krW
package NetFox; I9`R LSn
import java.io.*; Oop;Y^gG}
KGclo-,
b&;1b<BwD
public class FileAccessI implements Serializable{ oAkF
l0 H,TT~2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3 G?^/nB
RandomAccessFile oSavedFile; pH%cbBm
long nPos; Ab<4F7
-k p~pe*T
,))UQ7N
public FileAccessI() throws IOException {P_~_5o_
{ >69+e+|I
this("",0); ,Z;z}{.hq
} nz|;6?LCLY
NW`.RGLI<
xP.B,1\X
public FileAccessI(String sName,long nPos) throws IOException ,x?H]a)
{ {g2cm'hD
oSavedFile = new RandomAccessFile(sName,"rw"); IPU'M*|Q
this.nPos = nPos; )K8k3]y&
oSavedFile.seek(nPos); 5O Ob(
} 4-4lh TE(
C^S?W=1=w
)*I=>v.Jq
public synchronized int write(byte[] b,int nStart,int nLen) %6}S'yL
{ mN^92@eebC
int n = -1; 8z^?PZ/
try{ K2TO,J3 E
oSavedFile.write(b,nStart,nLen); {R7>-Y[4)2
n = nLen; nu] k<^I5|
} ={?}[E
catch(IOException e) OYJy;u3"
{ {_1^ GIIS
e.printStackTrace (); Z1FO.[FV
} zi23k=
M#JOX/
SzR0Mu3uK
return n; "-y\F}TE
} Sq&*K9:z
H(ht{.sjI
)EYsqj
} %Yg;s'F>#q
j=)Cyg3_%
XnQd(B`M
/* 2B_6un];W
**SiteInfoBean.java ;^:9huN
*/ ch<Fi%)
package NetFox; GV1\8OG7
QeA)@x.p
Y;je::"
public class SiteInfoBean { i+yqsYKO
:b;2iBVB
YNbs*i&
private String sSiteURL; //Site's URL zh'TR$+\hO
private String sFilePath; //Saved File's Path /I
private String sFileName; //Saved File's Name Qw^nN(K!>
private int nSplitter; //Count of Splited Downloading File hA?j"y0?
+15j^ Az
h:(Jes2
public SiteInfoBean() -gh',)R
{//nSplitter的缺省值为5 l!\C"f1o,
//default value of nSplitter is 5 %*<k5#Yq
this("","","",5); <pGPuw|~I
} g# :|Mjgh
j3VM!/
Q;{yIa$ $
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !o*BRR*
{ 6)P~3C'
sSiteURL= sURL; fcb:LPk;
sFilePath = sPath; Tfhg\++u
sFileName = sName; @QtJ/("&WC
this.nSplitter = nSpiltter; }1w[G;$
A6}M F
*Xt#04_
} r_]wa
E=w$r
C/e`O|G
public String getSSiteURL() ;u,%an<(
{ mwCNfwb:
return sSiteURL; C^Tc9
} -:m;ePK
WUAjb,eo
knpb$eX4
public void setSSiteURL(String value) X#5dd.RR
{ _< 69d
sSiteURL = value; "*#$$e53A
} ppVjFCv0<
BgD;"GD*W
GC H= X
public String getSFilePath() Mq42^m:qe
{ d6<,R;)
return sFilePath; u.0Z)j}N
} {gl-tRC3
][:6En}
_x z_D12
public void setSFilePath(String value) E3.=|]W'
{ JJ,Fh .
sFilePath = value; 0F`@/C1y55
} 9#/z[!
<!K2xb-d^
Y:G6Nd VFM
public String getSFileName() B8Jev\_
{ 0gHJ%m9s
return sFileName; w@.E}%bwq
} A2Rr*e
b0x9}
Xgd!i}6Q
public void setSFileName(String value) Tx0/3^\>8A
{ 17H_>a\`
sFileName = value; 1@E<5rp o
} 1;SW%\M
*f.eyg#
!y'LKze+G
public int getNSplitter() 0 '~Jr\4
{ Pp:(PoH
return nSplitter; ?;+=bKw0
} sL~TV([6/
f`p`c*
FM0)/6I'x
public void setNSplitter(int nCount) "f~S3?^!2
{ u q:>g
nSplitter = nCount; ~({aj|Y
} &B#HgWud
} `BMg\2Ud*
w@X<</`
]XJpy-U
/* U{h5uezD
**Utility.java c%Yvj
*/ g{8>2OK$c
package NetFox; <N=p_m 2T
C$aiOK-]+
`HgT5}
public class Utility { 7&:gvhw
JE9|;A
el.;T*Wn
public Utility() fa/ '4
{ Bca\grA
9,82Uta
??aOr*%
} '_g8fz 3
W&}R7a@:<~
//线程睡眠 MT$OjH'Q`
public static void sleep(int nSecond) ^]Lr_k
{ 7}%3Aw6]S
try{ ^g~Asz5]
Thread.sleep(nSecond); &y mfA{s
} t}qoIxy)
catch(Exception e) Io5-[d
{ | 3!a=
e.printStackTrace (); \5k[ "8~
} hBLJKSv
} aQMET~A:
X/];*='Q
//日志 I&YYw8&
public static void log(String sMsg) !0fpD'f!n
{ cA`R~o"
System.err.println(sMsg); R5r )01
} >UE_FC*u
EW0H"YIC
_wCp.[3?t
public static void log(int sMsg) ub{<m^|)
{ gr4Hh/V
System.err.println(sMsg); 4.|]R8Mn
} I`t"Na2i
} 0LrTYrlj
pxM^|?Hxc
+yVz) X
/* (JocnM|U
**TestMethod.java Dvo.yn|kB
*/ ;f^.7|
package NetFox; 3 {\b/NL$
z62e4U][
"7JO~T+v
public class TestMethod { S@z$,}Yc`<
d\3L.5]X
xQ* U9Wt;T
public TestMethod() )T(xQ2&r4
{ ///xx/weblogic60b2_win.exe R4_4FEo
try{ w-AF5%gX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m%+W{N4Wb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0 4x[@f`
SiteFileFetch fileFetch = new SiteFileFetch(bean); C^aP)& qt
fileFetch.start(); QSW03/_f
} gPT-zul
catch(Exception e){e.printStackTrace ();} 245(ajxHC
bkceR>h%
{K09U^JU
} .*r?zDV
F6}Pwz[c
DFwkd/3"
public static void main(String[] args) F8Rd#^9PD
{ )V!9&
new TestMethod(); X'TQtI
} /wljbb/s
} ?>1AT==wI
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