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)); q:}Q5gzZ
} DQ#rZi3I
for(int i=0;i<nEndPos.length-1;i++) df85g
{ [2WJ];FJ
nEndPos = nStartPos[i+1]; {~L{FG)O
} -^R6U~
nEndPos[nEndPos.length-1] = nFileLength; C'Gj\
} [UP-BX(
} ]RBT9@-:U
-k4w$0)
R]LRgfi9
//启动子线程 5ov F$qn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D7X8yv1
for(int i=0;i<nStartPos.length;i++) &3@{?K
{ IdHydY1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?.A~O-w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HITw{RPrW
nStartPos,nEndPos,i); }fS`jq;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fl{@B*3@w
fileSplitterFetch.start(); jV}tjwq
} *6C ]CS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E4CyW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4lVvs(W?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \sSt _|+
nEndPos = " + nFileLength); -@I+IKz
// fileSplitterFetch[nPos.length-1].start(); 2aDjt{7P
`FJ2 ?
u0o}rA
//等待子线程结束 %z9lCTmy
//int count = 0; $u ae8h
//是否结束while循环 >e'Hz(~'/
boolean breakWhile = false; vzXfJP
t)p. $
\f!j9O9S
while(!bStop) UPE9e
{ k=^~\$e
write_nPos(); x>ZnQ6x~m]
Utility.sleep(500); 0=:]tSD\F
breakWhile = true; =%i~HDiy
uQ(C,f[6p
e>6NO
for(int i=0;i<nStartPos.length;i++) E"/r*C+T
{ dE_d.[!
if(!fileSplitterFetch.bDownOver) t.s;dlx[@
{ *v}3So
breakWhile = false; oe4r_EkYwW
break; #;+ABV
} '5usPD
} ]Yw/}GKB
if(breakWhile) G`D~OI
break; [ Q@rW5,-
ji&%'h
~;QzV?%
//count++; q{c/TRp7
//if(count>4) }hm"49,O
// siteStop(); 3*v&6/K
} Gg,&~ jHib
gP13n!7
'(6 ^O=
System.err.println("文件下载结束！"); ;^"#3_7T]
} SjmWlf,
catch(Exception e){e.printStackTrace ();} ozCH1V{p
} cns~)j~
]di^H>,xU
4WAs_~
//获得文件长度 j,Vir"-)
public long getFileSize() Fr|Ts>Kx
{ # o;\5MOE%
int nFileLength = -1; (fTi1 I!
try{ p]]*H2UD
URL url = new URL(siteInfoBean.getSSiteURL()); A8zh27[w%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Vlf=gP
httpConnection.setRequestProperty("User-Agent","NetFox"); us,~<e0
|eu:qn8
E*W|>2nx]
int responseCode=httpConnection.getResponseCode(); JYesk
if(responseCode>=400) (Qp53g
{ 6?(Z f
processErrorCode(responseCode); PF+SHT'4}#
return -2; //-2 represent access is error (p1}i::Y8
} b\.l!vn0
Vz\?a8qQ<
+\ZaVi
String sHeader; .Bs~FIe^
e.n*IJ_fz
;;]^d_
for(int i=1;;i++) QcN$TxU>
{ QqdVN3#1z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *[ww;
//Utility.log(in.readLine()); o_#F,gze)S
sHeader=httpConnection.getHeaderFieldKey(i); 0kiV-yc
if(sHeader!=null) Ij_h #f
{ V|q`KOF
if(sHeader.equals("Content-Length")) 3;F+.{Icc
{ F8*zG 4/&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U 6`E\?d`
break; + 2j]
} <cUaIb;(4
} G?e\w+}Pj@
else p+y2w{{
break; D&]dlY@*
} D:I6nSoC
} F<Y>
catch(IOException e){e.printStackTrace ();} "b6ew2\
catch(Exception e){e.printStackTrace ();} RLE6=#4
Cu,#w3JR
-udKGrT+
Utility.log(nFileLength); Gc0/*8u/
j-n-2:Q
6<`tb)_2~
return nFileLength; VM"z6@
} ^;DbIo\6H
})TXX7[h
s6HfN'
//保存下载信息（文件指针位置） WW.amv/[a
private void write_nPos() >=VtL4K^
{ VYAz0H1-_
try{ QZO9CLX 8k
output = new DataOutputStream(new FileOutputStream(tmpFile)); 92pl#Igt
output.writeInt(nStartPos.length); qCUn. mI
for(int i=0;i<nStartPos.length;i++) vbMt}bM(GD
{ Dxx`<=&g
// output.writeLong(nPos); eI:;l];G9
output.writeLong(fileSplitterFetch.nStartPos); --'!5)U
output.writeLong(fileSplitterFetch.nEndPos); bKb}VP
} ><r\ 5`
output.close(); x/]]~@:
} 1cvH
catch(IOException e){e.printStackTrace ();} ecqL;_{o
catch(Exception e){e.printStackTrace ();} 1^R:[L4R`
} {T(z@0Xu
0%OV3`
JQdeI+
//读取保存的下载信息（文件指针位置） okSCM#&:[2
private void read_nPos() a?gziCmS?C
{ jC3)^E@:"
try{ 8r-'m%l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s<`54o ,
int nCount = input.readInt(); nLjc.Z\Bl
nStartPos = new long[nCount]; TQiDbgFo
nEndPos = new long[nCount]; {klyVb
for(int i=0;i<nStartPos.length;i++) +1(L5Do}
{ uHu(
nStartPos = input.readLong(); TxDzGC
nEndPos = input.readLong(); g0M9v]c
} 5IfyD ]<
input.close(); XL2iK)A
} #->#mshd4
catch(IOException e){e.printStackTrace ();} zSM;N^X8?
catch(Exception e){e.printStackTrace ();} (Tbw@BFk
} 5:6]ZFW
=0gfGwD{
- )brq3L
private void processErrorCode(int nErrorCode) se,0Rvkt
{ 7$/%c{o
System.err.println("Error Code : " + nErrorCode); idLCq^jnJ
} HyX:4f|]'
rZSX fgfr
_6/q.
//停止文件下载 Lr;PESV
public void siteStop() .C7;T'>!
{ 25-5X3(>j=
bStop = true; GJB=5nE
for(int i=0;i<nStartPos.length;i++) e/nc[
fileSplitterFetch.splitterStop(); :f|X$> b
dLnu\bSF
,f2tG+P
} w=K!U]
} tMnwY'
//负责部分文件的抓取 " +n\0j;
**FileSplitterFetch.java @!MhVNS_<
*/ o*}--d?S
package NetFox; ZA!yw7~
SeX:A)*ez%
?RI&7699+
import java.io.*; ^V5g[XL2
import java.net.*; @b,&b6V
JAA{5@ST
Ei& Z
public class FileSplitterFetch extends Thread { IP e"9xb
wg0hm#X
w\f>.N
String sURL; //File URL kV$$GLD\
long nStartPos; //File Snippet Start Position Ohe*m[
long nEndPos; //File Snippet End Position L^Q q[>
int nThreadID; //Thread's ID rh%-va9
boolean bDownOver = false; //Downing is over XDM~H
boolean bStop = false; //Stop identical '<v_YxEn
FileAccessI fileAccessI = null; //File Access interface 2B<0|EGtzw
' +*,|;?
(bBr O74lR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H;(|&Asq>
{ klqN9d9k
this.sURL = sURL; *k%3J9=-1
this.nStartPos = nStart; }M+2 ,#l
this.nEndPos = nEnd; $GcVI;a
nThreadID = id; JLZ=$d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LsGu-Y5^
} G"._]3CPF
1E'/!|
UvPD/qu$8D
public void run() 3Q-[)Z )
{ 28rC>*+z
while(nStartPos < nEndPos && !bStop) |DZ3=eWZ
{ w6w'Jx
FA#?+kd
! !9l@
try{ Er]lObfQo
URL url = new URL(sURL); `OP?[ f d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?*ni5\y5o
httpConnection.setRequestProperty("User-Agent","NetFox"); sKLH.@
String sProperty = "bytes="+nStartPos+"-"; 2*<'=*zaQ
httpConnection.setRequestProperty("RANGE",sProperty); 5/{";k)L+
Utility.log(sProperty); 3jG #<4;J
_s> ZY0
%C^%Oq_k
InputStream input = httpConnection.getInputStream(); /Wqx@#
//logResponseHead(httpConnection); jj&4Sv#>
FID4@--
|>2IgTh1a
byte[] b = new byte[1024]; zLa3Q\T
int nRead; [Q+qu>&HB7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RaNz)]+7`
{ O*d4zBT
nStartPos += fileAccessI.write(b,0,nRead); NX5A{
//if(nThreadID == 1) d|, B* N(w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~.,h12
} G',*"mZQ[
_\y%u_W
:y!%GJW
Utility.log("Thread " + nThreadID + " is over!"); BL&D|e
bDownOver = true; QlFt:?7f
//nPos = fileAccessI.write (b,0,nRead); H^e0fm
} kQY+D1
catch(Exception e){e.printStackTrace ();} E*F)jP,yo
} ^ew<|J2,B
} =:;KYuTr
xn)eb#r
l`}Ag8Q
//打印回应的头信息 <\If:
public void logResponseHead(HttpURLConnection con) uKBSv*AM
{ %j=xLV\
for(int i=1;;i++) V>2mzc
{ 0B;cQSH!q
String header=con.getHeaderFieldKey(i); s, 8a1o
if(header!=null) O!c b-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b35Z1sfD j
Utility.log(header+" : "+con.getHeaderField(header)); SB3=5"q
else ?<#2raH-
break; Y^(Sc4 W
} >(t_
} /0J1_g
DrTo")T
XazKS4(
public void splitterStop() ?5oeyBA@
{ Q.8)_w
bStop = true; dK=<%)N
} # XD-a
_E{hB
P=j89-e
} qPc"A!-i
]-D;t~
1;4] HNI
/* #''q :^EQ
**FileAccess.java rU{E}
*//文件访问(定位，写) CX8tTbuFl
package NetFox; ~ }<!ON;
import java.io.*; ^.d97rSm
nsCat($)
c<8RRYs
public class FileAccessI implements Serializable{ _(q|W3
N1LZXXY{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 MR/8
RandomAccessFile oSavedFile; $6c8<!B_
long nPos; l]s,CX
^:0epj7
<u"h'e/oW_
public FileAccessI() throws IOException U1>VKP;5Nn
{ {cNH|
this("",0); '~1uJ0H
} Q6?}/p
vIoV(rc+
#\[((y:q
public FileAccessI(String sName,long nPos) throws IOException [,F5GW{x
{ r="wd
oSavedFile = new RandomAccessFile(sName,"rw"); gGiLw5o,
this.nPos = nPos; l9J]<gG
oSavedFile.seek(nPos); nj7wc9z4
} z'G~b[kG4n
2{!^"iW
{ER%r'(4Z
public synchronized int write(byte[] b,int nStart,int nLen) QX*HvT
{ tsFwFB*
int n = -1; mv1_vF:
try{ QDRgVP
oSavedFile.write(b,nStart,nLen); ;plzJ6>
n = nLen; -1Luyuy/`
} 39W6"^q"o
catch(IOException e) 6E!CxXUX
{ 0nF>E@j^[
e.printStackTrace (); mxYsP6&
} O^D$ ~ ]
sW":~=H
ugM,wT&~Y
return n; "G8w}n:y
} 8q6b3q:c
7kBULeBn|
u"%i3%Yjh
} V01-n{~G
K#=)]qIk
HS|X//]
/* N{]|!#
**SiteInfoBean.java 4JTFdbx
*/ D3LW49
package NetFox; C} #:<Jx
u/5I;7cb
p",HF%
public class SiteInfoBean { t}E1NXW
mW_<c,3D.
/"t*gN=wrF
private String sSiteURL; //Site's URL ^AWM/aY
private String sFilePath; //Saved File's Path GdqT4a\S
private String sFileName; //Saved File's Name )+[{MR'
private int nSplitter; //Count of Splited Downloading File YQ`GOP#/
8F(_Vqu
eZ]4,,m
public SiteInfoBean() QD0upYG
{//nSplitter的缺省值为5 Y&O<A8=8
//default value of nSplitter is 5 I9ga8mG4-'
this("","","",5); XD5z+/F<"0
} _5^p+
V`KXfY
=OIxG}*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7XE/bhe%S
{ "}i\"x;s
sSiteURL= sURL; Go}C{(4T
sFilePath = sPath; I$4GM
sFileName = sName; _LV;q! /j
this.nSplitter = nSpiltter; =Tf uwhV
af]&3(33
ellj/u61bj
} V4GcW|P4y
eKlh }v
0kI.dX)
public String getSSiteURL() `Jh> 1l
{ R$@|t?
return sSiteURL; X[:&p|g]
} $cri"G
}>cQ}6n.
}LNpr
public void setSSiteURL(String value) #msXAy$N3r
{ f i-E_
sSiteURL = value; r'/7kF- 5
} b$P=rIB
8>Hnv]p
O2E6F^.pYw
public String getSFilePath() 8CxC`*L(
{ C7`FM@z
return sFilePath; r%hnl9
} }d2]QD#O
4/$ $?w4
v\#69J5.>)
public void setSFilePath(String value) >dol
{ 8$3G c"=
sFilePath = value; m'$]lf;*
} %|[+\py$Q
7WG"_A~V
RsS?ibozl
public String getSFileName() 1}mIzrY
{ oc,a
return sFileName; IZczHHEL`b
} Z 4uft
$u`y
zqg4@" p
public void setSFileName(String value) w%Tcx^:
{ Wyf+xr'Ky
sFileName = value; N5 SK_+
} AD4KoT&
q9w6 6R
k#TonT
public int getNSplitter() S,LW/:,
{ ,~t{Q*#_h
return nSplitter; yZbO{PMr
} <U=:N~L
N=&~3k
Dh0`t@
public void setNSplitter(int nCount) |s :b9sfA
{ m M!H}|
nSplitter = nCount; [G^ir
} ~p{.4n2:
} <;:M:{RZY
:\1:n
dI<s)!
/* Mt)`hR+2
**Utility.java m98j`t
*/ c6cGl]FL
package NetFox; WR=e$;
MNNPBE
Sc;WraEn2
public class Utility { GcQO&oq|
r*<)QP^B~
]?tsYXU j
public Utility() <l(6$~(-u
{ RuDn1h#u{
.WA(X5
A{lzQO
} 7nB@U$]-Sz
=jjUwcl
//线程睡眠 nmp(%;<exN
public static void sleep(int nSecond) 6|3$43J,F
{ ~M%r.WFpA
try{ ,2vPmff
Thread.sleep(nSecond); stz1e dP
} ymSGB`CP
catch(Exception e) A.m#wY8
{ .4A4\-Cqe
e.printStackTrace (); Ub%+8M
} C)/uX5
} K:fK!/
RG|]Kt8
//日志 8'?V5.6?|~
public static void log(String sMsg) W'6~`t
{ :^FOh*H
System.err.println(sMsg); 1SeDrzLA
} (UPkb$Qc
3}}~(
d paZ6g
public static void log(int sMsg) 2`/JT
{ rIp84}
System.err.println(sMsg); ET1/oG<@
} R| t"(6
} Ce}wgKzr
oqHI`Tu
.|$6Pi%!
/* oX@nWQBc_
**TestMethod.java utKtxLX"
*/ 'x BBQP
package NetFox; {`BC$V
9'C kV[
D`PnY&ffT
public class TestMethod { JzMPLmgG/
Udv5Y
f sAgXv
public TestMethod() nk9Kq\2f:
{ ///xx/weblogic60b2_win.exe gUzCDB^.:
try{ qlmz@kTb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); iD#HBo
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C"_f3[Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8P.UB{QNe
fileFetch.start(); X6%w6%su5
} [TvH7ott'1
catch(Exception e){e.printStackTrace ();} X*VHi
R:kNAtK
Q3,`'[ F
} >tXn9'S
Fy5xIRyI\F
'`$a l7D
public static void main(String[] args) n}PK0
{ {C Qo}@.7
new TestMethod(); He="S3XON
} ZvEcExA-
} l j*ELy
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