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)); `%5~>vPS
} /W @k:
for(int i=0;i<nEndPos.length-1;i++) o4l=oY:'
{ |PY*"Ul
nEndPos = nStartPos[i+1]; V']{n7a-
} J Gpy$T{t
nEndPos[nEndPos.length-1] = nFileLength; e5HHsR6
} '(.vB~m7*+
} `;\<Fr
dJYW8pcKT
{] Zet}2
//启动子线程 % a9C]?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (vXes.|+t
for(int i=0;i<nStartPos.length;i++) V39`J*fI
{ D(YNa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :OFL@byS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wgV?1S>Z
nStartPos,nEndPos,i); 7c7:B2Lq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !#' y#
fileSplitterFetch.start(); IFd2r;W8
} >AUj4d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &i8UPp%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'U%L\v,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )V6<'>1WZ
nEndPos = " + nFileLength); 6Y 4I $[
// fileSplitterFetch[nPos.length-1].start(); k>aWI
o$[alh;c+W
D?Y j5eOa
//等待子线程结束 A]WR-0Z7
//int count = 0; ZR"BxE0_k
//是否结束while循环 _(&XqEX
boolean breakWhile = false; \'}? j-8
+|OrV'
NR@n%p
while(!bStop) "A0J~YvYWJ
{ gbclk~kX
write_nPos(); A@HCd&h
Utility.sleep(500); ]"DsZI-glW
breakWhile = true; ]|#%`p56
FfET45"l
<lxE^M
for(int i=0;i<nStartPos.length;i++) c7[+gc5}
{ JS:AHJSz
if(!fileSplitterFetch.bDownOver) ^XbN&'^,HL
{ l^"HcP6
breakWhile = false; zK@DQ5
break; s+jL BY
} 9bVPMq7}i
} U$+G9
if(breakWhile) rERHfr`OU
break; ySXQn#}-,
`dpm{sn
OY?x'h
//count++; ]!=,8dY
//if(count>4) k#Bq8d
// siteStop(); N-Jp; D
} teDO,$
%I 3D/!%
z:+fiJB_
System.err.println("文件下载结束！"); gWZzOH*
} Bf-KCqC".
catch(Exception e){e.printStackTrace ();} CPj8`kl
} A['0~tOP
4#c-?mh_
WdvXVF
//获得文件长度 Vr1yj
public long getFileSize() zG0191f
{ q8_8rp-@
int nFileLength = -1; xD|CQo}:
try{ N)tqjq
URL url = new URL(siteInfoBean.getSSiteURL()); <Jwx|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >I^_kBa
httpConnection.setRequestProperty("User-Agent","NetFox"); [fjP.kw;J
( ;(DI^Un8
Tz"Xm/Gy
int responseCode=httpConnection.getResponseCode(); JJ=%\j
if(responseCode>=400) 7B"*< %<
{ $Z2Y%z6y
processErrorCode(responseCode); [$bK%W{f
return -2; //-2 represent access is error UW?(-_8
} `ywI+^b
(TjY1,f!H
ztRe\(9bL
String sHeader; ),u)#`.l G
(aQNe{D#
},W<1*|
for(int i=1;;i++) X\yy\`o
{ 4sCzUvI~Y1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Dno'-{-
//Utility.log(in.readLine()); `uN}mC!r]
sHeader=httpConnection.getHeaderFieldKey(i); 3{j&J-
if(sHeader!=null) )^^Eh=Kbj
{ $afE= qC*
if(sHeader.equals("Content-Length")) PAUepO_
{ {"x>ewAf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &LD=Zp%
break; 9BA*e-[
} }bZcVc2
} !eH9LRp
else #F~^m
break; ~g_]Sskf7
} 4*vV9*'!
} x%WL!Lo
catch(IOException e){e.printStackTrace ();} +"HLx%k
catch(Exception e){e.printStackTrace ();} F}C.F
{@7{!I|eD
s,*kWy"jp
Utility.log(nFileLength); 0kp#+&)+
>cE@m=[
.e,(}_[[<
return nFileLength; A3#^R%2)W
} cp&- 6 w+
@-ms_Z
UDUj
//保存下载信息（文件指针位置） wj$J}F
private void write_nPos() {}W9m)I
{ U~)i&":sN
try{ Y4 <
output = new DataOutputStream(new FileOutputStream(tmpFile)); XC D&Im
output.writeInt(nStartPos.length); -hpJL\ng
for(int i=0;i<nStartPos.length;i++) Q#2gjR r
{ ;<9dND
// output.writeLong(nPos); (i"@{[IP
output.writeLong(fileSplitterFetch.nStartPos); WN+D}z]
output.writeLong(fileSplitterFetch.nEndPos); c@]_V
} sr*3uI-)L
output.close(); "kHQ}#6r
} rphfW:
catch(IOException e){e.printStackTrace ();} zxV,v*L)
catch(Exception e){e.printStackTrace ();} rz
} b;;C><
Cqy)+x_OQ,
VX`E7Sf!}
//读取保存的下载信息（文件指针位置） iLyJ7zby
private void read_nPos() 6u'+#nm
{ X4D>
try{ 8!T6N2O6d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]0+5@c
int nCount = input.readInt(); x<S?"
nStartPos = new long[nCount]; 5dPPm%U{
nEndPos = new long[nCount]; lg(*:To3B
for(int i=0;i<nStartPos.length;i++) .YT&V
{ =y>g:}G7
nStartPos = input.readLong(); 0CTUcVM#9
nEndPos = input.readLong(); E[Rd=/P6
} sUki|lP
input.close(); "/O`#Do/
} Pz/bne;=
catch(IOException e){e.printStackTrace ();} ,dG2[<?o
catch(Exception e){e.printStackTrace ();} %O!~!'
} <![]=~z$
S\F;b{S1
)G a%Eg9
private void processErrorCode(int nErrorCode) _Kw<4$0<p
{ &f:"p*=a\
System.err.println("Error Code : " + nErrorCode); '4L0=G:A<q
} me7?
SS/9fT"[
)Hp{8c
//停止文件下载 JS&=V67[
public void siteStop() +a{P,fRl@
{ :ziV3jRM
bStop = true; l.V{H<v}
for(int i=0;i<nStartPos.length;i++) o!";&\,Ip
fileSplitterFetch.splitterStop(); 8l, R|$RKP
W6d[v/+K+
_9^
} K)z!e;r
} R`_RcHY:
//负责部分文件的抓取 YCWt%a*I'
**FileSplitterFetch.java |@rPd=G^(/
*/ ep<O?7@j-G
package NetFox; bm &$wf
vp4l g1/
[xTu29X.
import java.io.*; mihR *8p
import java.net.*; +~E;x1&'
p\7(`0?8VN
w=]bj0<A=
public class FileSplitterFetch extends Thread { D]{#!w(d
?dJ[?<aG
Y\Z.E;
String sURL; //File URL rhLm2q
long nStartPos; //File Snippet Start Position y(#Aze{yC
long nEndPos; //File Snippet End Position <vP{U
int nThreadID; //Thread's ID \5MW65
boolean bDownOver = false; //Downing is over )_|;h2I
boolean bStop = false; //Stop identical tqnvC UIE
FileAccessI fileAccessI = null; //File Access interface bpQ5B'9
r&u&$"c
}bW"Z2^nB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !c;Z<@
{ #i8] f{
this.sURL = sURL; K%+[2Hj2
this.nStartPos = nStart; q13bV
this.nEndPos = nEnd; 8:x{
nThreadID = id; Q*W`mFul
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y"x9B%e
} KqM!7
[SFX;v!9
9L$bJO-3
public void run() 8f""@TTp
{ JDQ7
while(nStartPos < nEndPos && !bStop) 7_HJ|QB
{ Y5 BWg
O0"u-UX{
: J3_g<@
try{ LSR{N|h+)
URL url = new URL(sURL); }#~DX!Sj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fp_?1y
httpConnection.setRequestProperty("User-Agent","NetFox"); sS 5aJ}Qs
String sProperty = "bytes="+nStartPos+"-"; Ik4FVL8~
httpConnection.setRequestProperty("RANGE",sProperty); hzT,0<nw
Utility.log(sProperty); O%1X[
?k5m1,fHW
^""Ss
InputStream input = httpConnection.getInputStream(); r+4<Lon~
//logResponseHead(httpConnection); N^)\+*tf1
d)_fI*:f
BrWo/1b
byte[] b = new byte[1024]; XM9}ax
int nRead; 'zEmg}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !)Y T_ib
{ X^?M4
nStartPos += fileAccessI.write(b,0,nRead); r#%e$
//if(nThreadID == 1) $jpAnZR- /
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J=%(f1X<W
} 20Umjw.D
[VD)DO5
i'[o,dbE
Utility.log("Thread " + nThreadID + " is over!"); 0|RFsJ"
bDownOver = true; [&tN(K9*
//nPos = fileAccessI.write (b,0,nRead); r )EuH.z
} cc*xHv^
catch(Exception e){e.printStackTrace ();} ?89K [D|
} Rxg^vM*
} l*v6U'J
TA2?Ia;@xV
t_VF=B^LuR
//打印回应的头信息 _(qU%B
public void logResponseHead(HttpURLConnection con) !|G 8b'
{ \Ax[/J2aO
for(int i=1;;i++) "kS(b4^
{ 8?YWE62
String header=con.getHeaderFieldKey(i); U{8]TEv
if(header!=null) %ut^ O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -f{NVX\<0
Utility.log(header+" : "+con.getHeaderField(header)); ~ AU!Gm.
else }i)^?@
break; 4Jf6uhaE
} h#Z5vH
} .L#xX1qr
@@?P\jv~
bv%A;
public void splitterStop() %,Pwo{SH
{ ySS kw7
bStop = true; "_g3{[es!
} 9d\B*OU
U2lDTRt
55mDLiA
} l"C)Ia&/
m(B,a,g<
*/T.]^
/* eJ=K*t|
**FileAccess.java /^m3?q[a
*//文件访问(定位，写) _o'3v=5T
package NetFox; [K*>W[n
import java.io.*; `4@_Y<
lZt{L0
Y$@?Y/rhR
public class FileAccessI implements Serializable{ z_A:MoYfo
g9rsw7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B{In "R8
RandomAccessFile oSavedFile; &!adW@y
long nPos; ;;*'<\lP.j
Q>G lA
1L4-hYtCj
public FileAccessI() throws IOException ^:(:P9h
{ Ykt{]#
this("",0); 5S;|U&f|
} H.n+CR
}Q=@$YIesD
"TLY:V
public FileAccessI(String sName,long nPos) throws IOException n#NE.ap$&,
{ ?HsQ417.H
oSavedFile = new RandomAccessFile(sName,"rw"); ]]InD N
this.nPos = nPos; 7AOjlC9R}
oSavedFile.seek(nPos); XDot3)2`
} "!fvEE
Qd{h3K^hlu
uTX0lu;
public synchronized int write(byte[] b,int nStart,int nLen) Nydhal00
{ &3o[^_Ti
int n = -1; FtEmSKD
try{ 7jf%-X
oSavedFile.write(b,nStart,nLen); DKvNQ:fI>9
n = nLen; 6G6B!x
} f19~B[a
catch(IOException e) ssWSY(j]
{ x}c%8dO#J
e.printStackTrace (); F1q a`j^'
} *<5zMSZO
W=$cQ(x4Z
SviGLv;oR
return n; #nzVgV]
} .Lvg $d
bsn.HT"5
/.Fvl;!J;
} ,pg\5b
$PNS`@B
JyfWy
/* d{gj8
**SiteInfoBean.java ~<)CI0=
*/ >_<J=8|E
package NetFox; OE"r=is
=VctG>ct|
\0^ZNa?
public class SiteInfoBean { f:).wi Ld
v4YY6?4
<21@jdu3n,
private String sSiteURL; //Site's URL y{`aM(&
private String sFilePath; //Saved File's Path Wl4T}j
private String sFileName; //Saved File's Name c^$+=-G{fd
private int nSplitter; //Count of Splited Downloading File (I) e-1
E>|xv#:~DV
}+" N '
public SiteInfoBean() ?11\@d
{//nSplitter的缺省值为5 4raKhN"
//default value of nSplitter is 5 CQ(;L{}
this("","","",5); xIrRFK9[Q
} 8%Wg;:DZx
;`TSu5/
3 E~d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3XOf-v:~
{ 4Y=sTXbFt
sSiteURL= sURL; y*AB=d^
sFilePath = sPath; h /.^iT
sFileName = sName; B!#F!Wk"
this.nSplitter = nSpiltter; X`,]@c%C`
Ga%x(1U[&
,z*-93H1
} Gz>M`M`[4
]Q%|69H}B
syseYt]
public String getSSiteURL() Yy_o*Ozq
{ nCj_4,O
return sSiteURL; 9aE.jpN
} T\Zq/Z\
|.s#m^"
TDMyZ!d
public void setSSiteURL(String value) WC?}a^ 8
{ 'A|OVyH
sSiteURL = value; e2onR~Cf
} H"_]Hq
q*h1=H52
:=0XT`iY
public String getSFilePath() nhUL{ER
{ ^J([w~&
return sFilePath; uAWmg8
} gEE6O%]g
o*L#S1yL
e-taBrl;
public void setSFilePath(String value) kH)JBx.
{ +>F #{b
sFilePath = value; ,sM>{NK9R
} ,w+}Evp])
%?4G^f
HfF4BQxm
public String getSFileName() #*g.hL<
{ `#m>3
return sFileName; 9O%4x"*PO
} )ny,vcU]
Rj/9\F3H
L 1fK
public void setSFileName(String value) V?k"BU
{ OZw<YR
sFileName = value; 7\q_^
} E rf$WPA
05|,-S
wc-ll&0Z
public int getNSplitter() aWLeyXsAu
{ h%hE$2
return nSplitter; I& `>6=)
} 'k9?n)<DW
~vCfMV[F
S[TJ{L(
public void setNSplitter(int nCount) `f@VX :aL}
{ ~okIiC]#
nSplitter = nCount; xELnik_L2
} Kp|#04]
} . k6)
H& #Od?
yrDWIU(8;6
/* ZUvA`
**Utility.java m-SP#?3
*/ u%^Lu.l_c
package NetFox; DIk\=[{2q
=,aWO7Pz
5X7kZ!r
public class Utility { !f(aWrw7e6
S;o U'KOY
)$#r6fQO
public Utility() iwHy!Vi-5
{ _HT*>-B
/12D >OK
I6]|dA3G
} [\hk_(}
*>=vSRL0_
//线程睡眠 ]~,V(K
public static void sleep(int nSecond) L"i B'=
{ u5f+%!p
try{ x 5u.D^
Thread.sleep(nSecond); cx]O#b6B.
} ZKGS?z
catch(Exception e) Tl#Jf3XY}
{ XFeeNcqF
e.printStackTrace (); M y:9
} CS 7"mE`{
} s*gyk
Dm@wTt8N(
//日志 XUD/\MoV
public static void log(String sMsg) ub"(,k P
{ s$Il;
System.err.println(sMsg); 3:$hC8
} !b O8apn
7'[C+/:
tQ7DdVdix
public static void log(int sMsg) gTK5z.]
{ hT&,5zaWdv
System.err.println(sMsg); (D'Z4Y
} 5zlgmCGow
} guC/eSxv
9T47U; _)
GHHErXT\a
/* qYg4H|6
**TestMethod.java WgdL^PN(h
*/ 9Z0(e!b4S
package NetFox; U~8.uldnF
S9Fg0E+J
w;.'>ORC
public class TestMethod { ZQvpkO7}M
>G2o
u7u8cVF
public TestMethod() 1#AdEd[
{ ///xx/weblogic60b2_win.exe _nR8L`l*z
try{ TEZ^Ia
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o~ .[sn5l-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W{Cc wq
SiteFileFetch fileFetch = new SiteFileFetch(bean); Kp*nOZ
fileFetch.start(); (o_fY.
} >4a@rT/
catch(Exception e){e.printStackTrace ();} &XosDt
A>6b 6
pti`q)
} 9i)E<.6
\?[#>L4
3,j)PKf ;
public static void main(String[] args) -OpI,qyS
{ 4#uWj?u
new TestMethod(); $Yt29AQ
} ,\;;1Kq
} 'Y+AU#1~H
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