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)); Glr.)PA
} sig_2;
for(int i=0;i<nEndPos.length-1;i++) 3N21[i2/m
{ ;vx9xs?6
nEndPos = nStartPos[i+1]; HTG;'$H^
} /P%:u0fX,
nEndPos[nEndPos.length-1] = nFileLength; >JMKEHl.q
} S'e2~-p0F
} Ui.F<,E
^eRuj)$5A
WveFB%@`;
//启动子线程 1,J.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x@ O:
for(int i=0;i<nStartPos.length;i++) $b$D[4
{ }R x%&29&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {%Y7]*D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;sf/tX
nStartPos,nEndPos,i); +A3H#'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a*8}~p,
fileSplitterFetch.start(); (!(bysi9
} F*=RP$sj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B+LNDnjO]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V_kE"W)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", sFTIRVXN,
nEndPos = " + nFileLength); Y(f-e,
// fileSplitterFetch[nPos.length-1].start(); xd3
2o/`8+eJu
Fqv5WoYVf
//等待子线程结束 F8I<4S
//int count = 0; @n(In$
//是否结束while循环 ^q`*!B9@
boolean breakWhile = false; Vmc)or*#
ZJ(!jc$"*%
aBnbu vp
while(!bStop) ccSSau5N
{ v#FUD-Z
write_nPos(); C(t/:?(y
Utility.sleep(500); 96avgyc
breakWhile = true; luT8>9X^:a
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c"ztrKQQ
for(int i=0;i<nStartPos.length;i++) 'Ap5Aq
{ \YS?}! 0
if(!fileSplitterFetch.bDownOver) nz\fN?q
{ rWXW}Yg
breakWhile = false; |9I;`{@
break; O)R0,OPb
} B .mV\W
} M}Mzm2d#`
if(breakWhile) *@nUas2"
break; ?s]`G'=>V`
JPG!cX%
4/?Zp4g
//count++; fna>>
//if(count>4) gOM`I+CwT
// siteStop(); pS;dvZ
} D.b<I79bX
0 y%R
}[`?#`sW
System.err.println("文件下载结束！"); t,,^^ll
} v"+EBfx
catch(Exception e){e.printStackTrace ();} $wTX
} b3lpNJ J
f,>i%.
<4,?lZ
//获得文件长度 }o-P
public long getFileSize() 8B/9{8
{ uw!|G>
int nFileLength = -1; "S:N-Tf%U
try{ 8A.7=C' z
URL url = new URL(siteInfoBean.getSSiteURL()); 'wrpW#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tqCg<NH.!m
httpConnection.setRequestProperty("User-Agent","NetFox"); [@Y q^.6t
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bobkT|s^s
int responseCode=httpConnection.getResponseCode(); I:<R@V<~#
if(responseCode>=400) m=B0!Z1xx
{ !++62Lf
processErrorCode(responseCode); 9K<a}QJP
return -2; //-2 represent access is error FOi`TZ8
} ~*[4DQ[\
5FI>T=QF
RfG$Px '
String sHeader; "lf3hWGw
9G+rxyWMW
D:tZiS=0
for(int i=1;;i++) ycD.:w p\'
{ ZiYzsn
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V JL;+
//Utility.log(in.readLine()); d|RmU/)
sHeader=httpConnection.getHeaderFieldKey(i); a|uZJ*
if(sHeader!=null) 1C=P#MU`
{ FSs$ ] d;
if(sHeader.equals("Content-Length")) P'9io!Z-s
{ WI_mJ/2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]_8I_VcQ
break; }92lr87
} L$Ar]O)
} J6D$ i+
else Ilb |:x"L
break; Fjt,
} $ n[7
} :-" jKw
catch(IOException e){e.printStackTrace ();} z|)1l`
catch(Exception e){e.printStackTrace ();} [Od9,XBa
.fY<"2g
l>Ja[`X@
Utility.log(nFileLength); y4rJ-
':)j@O3-
PJ:5Lb<
return nFileLength; $ywh%OEH
} E=lfg8yb:
b2%bgs
]},Q`n>$
//保存下载信息（文件指针位置） y7EX&
private void write_nPos() 1e&b;l'*=
{ ![ID0}MjJ
try{ 14!a)Ijl
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9k[},MM
output.writeInt(nStartPos.length); @i-@mxk6<
for(int i=0;i<nStartPos.length;i++) {<[tYZmj.
{ b:cK>fh0_
// output.writeLong(nPos); ~{Rt4o _W
output.writeLong(fileSplitterFetch.nStartPos); :k(t/*Nl3
output.writeLong(fileSplitterFetch.nEndPos); Z;SG<
} R${4Q1
output.close(); lY9M<8g
} N%|Vzc
catch(IOException e){e.printStackTrace ();} xh^ZI6L<
catch(Exception e){e.printStackTrace ();} /M*\t.[ 46
} 8;f<qu|w
PG[O?l
{)9HS~e T
//读取保存的下载信息（文件指针位置） @<TZH
private void read_nPos() {&u7kWD|
{ !_H8Q}a
try{ |SukiXJZF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f<4q]HCa
int nCount = input.readInt(); )X!DCL:16
nStartPos = new long[nCount]; | 4oM+n;Y
nEndPos = new long[nCount]; J~'Q^O3@
for(int i=0;i<nStartPos.length;i++) uNZ>oP>
{ ^ R^N`V
nStartPos = input.readLong(); B "F`OS[
nEndPos = input.readLong(); ^O Xr: P
} JKi@Kw
input.close(); s5aOAyb*w
} (VPM>ndkw
catch(IOException e){e.printStackTrace ();} 1S]gD&V
catch(Exception e){e.printStackTrace ();} [Ro0eH
} /Q>{YsRRB
3/IWO4?_
],}afa!A
private void processErrorCode(int nErrorCode) wt=>{JM
{ E(3+o\w
System.err.println("Error Code : " + nErrorCode); &G|jzXE
} YEPG[W<kg
5OW8G][
b|8>eY
//停止文件下载 ,#jhKnk2e
public void siteStop() +9 p`D
{ #JR,C -w
bStop = true; &c?hJ8"
for(int i=0;i<nStartPos.length;i++) Ed0>R<jR9
fileSplitterFetch.splitterStop(); q|$>H6H4b
W*rU,F|9
,{ L;B
} f'`nx;@X
} Re,$<9V
//负责部分文件的抓取 s!;VUr\
**FileSplitterFetch.java pg}+lYGP
*/ .UhBvHH
package NetFox; ZDkD%SCy
rE{Xo:Cf
IL[|CB1v
import java.io.*; E%\7Uo-
import java.net.*; w]Ko/;;^2
90h1e7ZcC
:_QAjU
public class FileSplitterFetch extends Thread { ['Y+z2k
|RAQ%VXm
:CkR4J!m3
String sURL; //File URL o=RqegL
long nStartPos; //File Snippet Start Position _`X#c-J
long nEndPos; //File Snippet End Position 2hwXWTSu
int nThreadID; //Thread's ID "X{aS}
boolean bDownOver = false; //Downing is over Y0u'@l_[F
boolean bStop = false; //Stop identical 7fW=5wc
FileAccessI fileAccessI = null; //File Access interface )Rhff$
\abAPo
|CZnq-,C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Oz#EGjz
{ 78a-3){
this.sURL = sURL; VmOFX:j!,
this.nStartPos = nStart; bDFCZH-:'O
this.nEndPos = nEnd; (&P0la1
nThreadID = id; gR-Qj
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [#>$k 6F*
} ZP63Alt
u_6BHsU
IzGB
public void run() R<lNk<
{ ]zvVY:v
while(nStartPos < nEndPos && !bStop) +>!B(j\gx
{ 5e/qgI)M5
l@tyg7CwY
MCi`TXr
try{ ^0s\/qyqm
URL url = new URL(sURL); J%\~<_2ny
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x'@32gv
httpConnection.setRequestProperty("User-Agent","NetFox"); Y0X"Zw
String sProperty = "bytes="+nStartPos+"-"; >: W-C{%
httpConnection.setRequestProperty("RANGE",sProperty); 4QjWZ Wl
Utility.log(sProperty); i#]aV]IT
HL(U~Q6JQ
H7yg9zFT N
InputStream input = httpConnection.getInputStream(); o1#:j?sN
//logResponseHead(httpConnection); AJ#m6`M+EK
.W@(nQ-<
s?@)a,C%k
byte[] b = new byte[1024]; <nb3~z1
int nRead; $p0 /6c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DD@)z0W
{ O+E1M=R6h
nStartPos += fileAccessI.write(b,0,nRead); S}m$,<x
//if(nThreadID == 1) 1(%>`=R8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1A?\BJ"
} 5U)ab3:
}#ep}h
#j^('K|
Utility.log("Thread " + nThreadID + " is over!"); >9.5-5"
bDownOver = true; Wiq{wxe
//nPos = fileAccessI.write (b,0,nRead); 0j{F^rph
} joChML_
catch(Exception e){e.printStackTrace ();} C?[a3rNH(
} B|Fl,55
} uO ?Od
]<8B-D?Z
X/E7o92\
//打印回应的头信息 Z@uTkqG)
public void logResponseHead(HttpURLConnection con) %qS]NC
{ bSrRsgKvT
for(int i=1;;i++) w\o)bn
{ + %MO7vL
String header=con.getHeaderFieldKey(i); (Pk"NEP
if(header!=null) aJ5H3X}Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pK6e/eC
Utility.log(header+" : "+con.getHeaderField(header)); mfeMmKFu\
else HBh` 2Q
break; mFqSD
} d)04;[=
} fjIcB+Z
_e?q4>B)c
>Lw}KO`
public void splitterStop() UTDcX
{ 5!'R'x5e
bStop = true; WCuzV7tw
} E\]OySC%C$
Y8)E]D
p~Hvl3SxR
} =y<">-
ET,Q3X\Oe
y:[BP4H?y
/* <#+oQ>5s
**FileAccess.java eeW' [
*//文件访问(定位，写) LbJtpwz>z
package NetFox; 0$eyT-:d
import java.io.*; ~9JW#HHzn
XJx,9trH
$nB-ADRu@
public class FileAccessI implements Serializable{ !;o\5x<'$O
]ZzoJ7lr
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uQGz;F x
RandomAccessFile oSavedFile; AVXX\n\_
long nPos; `y\*m]:
ds*m6#1b
_\ .
public FileAccessI() throws IOException <u/a`E?
{ _4P;+Y
this("",0); v!NB~"LQ
} uP{;*E3?
X}oj_zsy;^
rQ9*J
public FileAccessI(String sName,long nPos) throws IOException _Kc1
{ Dh2:2Rz=#7
oSavedFile = new RandomAccessFile(sName,"rw"); 2.[_t/T
this.nPos = nPos; "| Kf'/r
oSavedFile.seek(nPos); s1X]RXX&j
} n?'d|h
&EAk z
[096CK
public synchronized int write(byte[] b,int nStart,int nLen) )46 0Ed
{ rkxW UDl
int n = -1; :{[<g](
try{ u5Qp/ag?N
oSavedFile.write(b,nStart,nLen); `S"W8_m
n = nLen; M[ x_#m|
} dCB&c^
catch(IOException e) U?bG`. X
{ 9*#$0Y=
e.printStackTrace (); _h0-
} c{1V.
Da"yZ\4
nIfN"
return n; 'UY[ap
} ]EB6+x!G
12idM*
'@'B>7C#
} vG Y!4@[
Y4QLs^IdB
>@^<S_KVh
/* RnHQq'J|\
**SiteInfoBean.java as>:\hjP##
*/ d i!"IQAvK
package NetFox; |2z}Xm5\
{tPnj_|n<
m"n.Dz/S
public class SiteInfoBean { \CcmePTN#x
(nGkZ}p
F[5S(7M 7
private String sSiteURL; //Site's URL egfi;8]E
private String sFilePath; //Saved File's Path Osnyd+dJY
private String sFileName; //Saved File's Name E]NY (1
private int nSplitter; //Count of Splited Downloading File GGH;Z WSe
#C4|@7w%
'<TD6jBs
public SiteInfoBean() Hw Z^D=A
{//nSplitter的缺省值为5 0z/h+,
//default value of nSplitter is 5 IWQ&6SDW$z
this("","","",5); Bb~5& @M|N
} d+tj%7
0f1H8zV
DB#$~(o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g[M]i6h2
{ hHpx?9O+!
sSiteURL= sURL; tyB)HF
sFilePath = sPath; 8$ic~eJ
sFileName = sName; 1YFeVMc
this.nSplitter = nSpiltter; (#oYyM]
2xDQ:=ec
J==}QEhQ{
} qmEoqU
z OtkC3hY
f3!n$lj
public String getSSiteURL() h6g:(3t6m
{ L/BHexOB
return sSiteURL; !}ilN 1>
} {gsW(T>)
Vc|NL^
*%X.ym'
public void setSSiteURL(String value) T8U[xu.>
{ =^Th[B
sSiteURL = value; q-YL]PgV
} 0 sZwdO
|) O):
%l,4=TQ[m
public String getSFilePath() bhYU5I 9
{ ha5e(Hj?
return sFilePath; mf}\s]_c
} >PIPp7C
8 }-7{
ABcBEv3
public void setSFilePath(String value) [m\,+lG?)j
{ 8'KMxR
sFilePath = value; iX{H,-C
} bo1I&I
vO]J]][
'*4iqPR;
public String getSFileName() MI\]IQU
{ Ir/:d]N*
return sFileName; \#++s&06
} Pg Syt
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;1@C_5C
public void setSFileName(String value) ^sV|ck
{ ZOuR"9]
sFileName = value; a%E8(ms37y
} ENq"mwV|
=:gjz4}_8
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public int getNSplitter() @0|nq9l1
{ z?kd'j`FG
return nSplitter; !lhFKb;
} <GaT|Hhc=
B9*Sfw%
&:No}6
public void setNSplitter(int nCount) t!{x<9
{ l<xFnj
nSplitter = nCount; FZp<|t
} n'?4.tb
} ^X&)'H
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)|RZa|`-G
/* J)*8|E9P
**Utility.java Hd0Xx}3&
*/ VhvTBo<cw
package NetFox; (B:uc_+
.!yq@Q|=u
| ]# +v@
public class Utility { C_G1P)k
zh%qS~8Yv
2ce'fMV
public Utility() O&V[g>x"U
{ rz.IoQo
3]^'
<Oa9oM},d
} t8vc@of$c,
gI{ =0
//线程睡眠 6vobta^w
public static void sleep(int nSecond) 6m+W#]^
{ JNBT^=x
try{ R hio7C
Thread.sleep(nSecond); U:n*<l-k}
} EkZjO Ci
catch(Exception e) fhRjYYGI
{ F7T E|LZ
e.printStackTrace (); ]fE3s{y &-
} p=B?/Sqa
} y(v_-6b
o/1JO_41
//日志 RZh}:
public static void log(String sMsg) X+iK<F$
{ <d"Gg/@a
System.err.println(sMsg); f`|G]da-3o
} X NE+(Bt
}0;Sk(B>
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public static void log(int sMsg) \Ye%o}.{
{ 0T))>.iu#
System.err.println(sMsg); {eR9 ;2!
} {|6z+vR
} gz61FW
GNU;jSh5
s;1e0n
/* z0Xa_w=
**TestMethod.java ?3jdg]&
*/ HO5d%85
package NetFox; a$m_D!b~_
9m8ee&,
C:GvP>
public class TestMethod { fxtxu?A>
o56kp3b)b
~@P)tl>
public TestMethod() j=ihbR^]Tl
{ ///xx/weblogic60b2_win.exe Q2c*.Y
try{ S}7>RHe
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RmOyGSO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WZ?!!
SiteFileFetch fileFetch = new SiteFileFetch(bean); bulboyA&#
fileFetch.start(); T~J?AKx
} ]l[2hy= cV
catch(Exception e){e.printStackTrace ();} l>7r2;
J]fS({(\I
|zpx)8Q
} e{C6by"j{S
F=}Z51|:~
2Va4i7"X\
public static void main(String[] args) c7qwNs*f
{ % {Q-8w!
new TestMethod(); RrWNJ&o
} vg(K$o{BT
} f&yQhe6q
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