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)); /Z% ?;
} k}O|4*.BT
for(int i=0;i<nEndPos.length-1;i++) 9D| FqU |
{ #0P<#S^7
nEndPos = nStartPos[i+1]; 5\'%zZ,l
} +Va?wAnr
nEndPos[nEndPos.length-1] = nFileLength; g764wl
} WR-C_1-pT
} FvNO*'xP
i&30n#
C>u 3n^
//启动子线程 >4VU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !'gz&3B~h
for(int i=0;i<nStartPos.length;i++) "''<:K|
{ m0* B[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y5NbY02E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b{ozt\:M
nStartPos,nEndPos,i); ."^dJ |fN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _Pz3QsV9
fileSplitterFetch.start(); j(BS;J$i
} |HU qqlf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]q3Kd{B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7E5Dz7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T7T!v
nEndPos = " + nFileLength); <F3sQAe
// fileSplitterFetch[nPos.length-1].start(); 2at?9{b
0>;#vEF*1
g@y" B6X
//等待子线程结束 X|QCa@Foe
//int count = 0; UbibGa= )
//是否结束while循环 9j2I6lGQ
boolean breakWhile = false; bc4x"]!
__fR #D
Y) h%<J
while(!bStop) 8(KfX%
{ ~76.S
write_nPos(); t? A4xk
Utility.sleep(500); y;Zfz~z
breakWhile = true; mce`1Tjw
~fF}
\O8f~zA{G
for(int i=0;i<nStartPos.length;i++) mc+wRx
{ g Oj5c
if(!fileSplitterFetch.bDownOver) bGi_", 8
{ !bcbzg2d&
breakWhile = false; bZ9NnSuH
break; F=om^6G%X5
} 5Hm!5:ZB
} {^kG<v.vV
if(breakWhile) QO7:iSZJ
break; by U\I5
?iLd5 Z
,?`1ve_K<
//count++; IeB6r+4|
//if(count>4) NslA/"*
// siteStop(); H|)1T-%
} :ky<`Jfr`
9$,gTU_a
Tb={g;0@
System.err.println("文件下载结束！"); M96( Rg
} 9i<-\w^$
catch(Exception e){e.printStackTrace ();} _o?(t\B9{
} c9uT`h
a-E-hX2
w~U`+2a3
//获得文件长度 rc$!$~|I3Z
public long getFileSize() 6}T%m?/}
{ v|I5Gz$qpa
int nFileLength = -1; ~8m>DSs)D
try{ 1D[P\r-
URL url = new URL(siteInfoBean.getSSiteURL()); xNm32~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _0*>I1F~
httpConnection.setRequestProperty("User-Agent","NetFox"); p},Fwbl
Kyp0SZp[
Di'u%r
int responseCode=httpConnection.getResponseCode(); (`]*Y(/2G
if(responseCode>=400) i5KwYoN
{ S8OVG4-
processErrorCode(responseCode); DjzUH{6O
return -2; //-2 represent access is error )6Q0f
} ~snF20
PS(j)I3
S9NN.dKu
String sHeader; m_$I?F0
+qj*P9
EOX_[ek7
for(int i=1;;i++) 06^1#M$'
{ ZGpTw[5ql
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @pGlWw9*
//Utility.log(in.readLine()); uT}TSwgp
sHeader=httpConnection.getHeaderFieldKey(i); b3b~T]]
if(sHeader!=null) UB$`;'|i
{ 2rCY&8
if(sHeader.equals("Content-Length")) }=hoATs
{ X^D9)kel
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2-V)>98
break; ;hA7<loY
} 7_40_kwJi
} 2ly,l[p8
else eq~c
break; `MsYgd
} T_x+sv=|X!
} @qPyrgy
catch(IOException e){e.printStackTrace ();} As+;qNO
catch(Exception e){e.printStackTrace ();} N 2"3~ #
W/r mm*
uR;-eK
Utility.log(nFileLength); 48CI8[T
7p.h{F'A
QG|GXp_q`
return nFileLength; U>_IYT
} 9*|3E"Vr
%md^S |
V 7l{hEo3?
//保存下载信息（文件指针位置） ?JgO-.
private void write_nPos() H_?B{We
{ hOB\n!
try{ pf8O`e,Awf
output = new DataOutputStream(new FileOutputStream(tmpFile)); $}nh[@
output.writeInt(nStartPos.length); XalJo@%-
for(int i=0;i<nStartPos.length;i++) 9c6GYWIFt&
{ h ??C4z
// output.writeLong(nPos); c',:@2R
output.writeLong(fileSplitterFetch.nStartPos); &'(a$S>v
output.writeLong(fileSplitterFetch.nEndPos); rMHQzQ0%
} ?7uKP}1|
output.close(); )@,90Vhh
} 1/2V.:bg
catch(IOException e){e.printStackTrace ();} #$=8g RZj
catch(Exception e){e.printStackTrace ();} H=&/Q
} WBr:|F+~s
hDljY!P>p
9$+^"ilk
//读取保存的下载信息（文件指针位置） fJWxJSdi
private void read_nPos() rg5]`-!=
{ R3j#WgltP
try{ m-ph}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [v0ri<sm
int nCount = input.readInt(); "J pTE \/
nStartPos = new long[nCount]; {?*<B=c
nEndPos = new long[nCount]; TF=k(@9J?
for(int i=0;i<nStartPos.length;i++) 3qiJwo>
{ ypD<2z^
nStartPos = input.readLong(); z!s.9
nEndPos = input.readLong(); +9zJlL^A%
} VW9>xVd4
input.close(); d1V^2Hb?
} DD!MGf/
catch(IOException e){e.printStackTrace ();} [0u.}c;(
catch(Exception e){e.printStackTrace ();} EmX>T>~#D
} 9zZ5Lr^21
;%u_ ;,((
Dxt),4%P
private void processErrorCode(int nErrorCode) +Y>"/i. N
{ RCBf;$O
System.err.println("Error Code : " + nErrorCode); :8^M5}
} O3kg
~h)@e\Kc
6?V<BgCC
//停止文件下载 ]C16y. ~e
public void siteStop() ;&Bna#~B
{ ietRr!$.
bStop = true; sI&i{D
for(int i=0;i<nStartPos.length;i++) xF( bS+(o
fileSplitterFetch.splitterStop(); A*8m8Sh$
\3Dk5cSDk+
<<=e9Lh
} 8]q
} CmEpir{}(
//负责部分文件的抓取 ,3Wb4so
**FileSplitterFetch.java L*g. 6+2
*/ 5Vp;dc
package NetFox; JEWL)
d/D,P=j"
0]AN;
import java.io.*; )0#j\B
import java.net.*; D##+)`dK
2+?T66 g
sm 's-gD
public class FileSplitterFetch extends Thread { G2.|fp_}pG
Bo`Tl1K#
{=3J/)='
String sURL; //File URL X'fuF2owd
long nStartPos; //File Snippet Start Position -S"5{N73
long nEndPos; //File Snippet End Position q#P$'7"
int nThreadID; //Thread's ID v(DwU!
boolean bDownOver = false; //Downing is over I eG=J4:*
boolean bStop = false; //Stop identical P$Z}
FileAccessI fileAccessI = null; //File Access interface o#qH2)tb
Y3-gUX*w0
25 CZmsg
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x_*%*H
{ Kv(z4z
this.sURL = sURL; *~p(GC
this.nStartPos = nStart; !^m%O0DT
this.nEndPos = nEnd; 8b|OXWl
nThreadID = id; u!Xb?:3uj
fileAccessI = new FileAccessI(sName,nStartPos);//定位 kv6Cp0uFg
} bS.s?a
33Jd!orXU
[J^
public void run() Cyq?5\a
{ -LtK8wl^
while(nStartPos < nEndPos && !bStop) m9in1RI%
{ +`@M*kd
q\%cFB}
j5Qo*p
try{ {7*>Cv}
URL url = new URL(sURL); ^/HW$8wEi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lbQQtpEKO
httpConnection.setRequestProperty("User-Agent","NetFox"); nq"evD5
String sProperty = "bytes="+nStartPos+"-"; `vd= ec
httpConnection.setRequestProperty("RANGE",sProperty); '+j<n[JLC
Utility.log(sProperty); _AFQ>j
$B;_Jo\|
WJ|:kuF
InputStream input = httpConnection.getInputStream(); ~9\$5n)a
//logResponseHead(httpConnection); eG5Y+iL-V
='Q{R*u
n]Zk;%yL
byte[] b = new byte[1024]; 6i.gyD
int nRead; aSC9&Nf;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )p<WDiX1!e
{ y<pnp?x4
nStartPos += fileAccessI.write(b,0,nRead); c.AYxI"
//if(nThreadID == 1) ~vHk&r]|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7p.>\YtoR}
} ]1D%zKY%$Z
xg<Hxn,<M
k|xtrW`qo;
Utility.log("Thread " + nThreadID + " is over!"); O.,3|
bDownOver = true; hfqqQ!,l!
//nPos = fileAccessI.write (b,0,nRead); ~*M$O&
} r> k-KdS
catch(Exception e){e.printStackTrace ();} "g>.{E5
} ~e `Bq>
} KzjC/1sd
c~0{s>
oc7$H>ET1
//打印回应的头信息 CS 8jA\
public void logResponseHead(HttpURLConnection con) TX}T|ri
{ .f:n\eT):
for(int i=1;;i++) l.`u5D
{ .~>?*}
String header=con.getHeaderFieldKey(i); 0fm*`4Q
if(header!=null) 'OkGReKt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?WUF!Jk
Utility.log(header+" : "+con.getHeaderField(header)); +-<}+8G;
else z0%\OhuCcf
break; iYJZvN
} 1TS0X:TCn
} jCioE
-`b8T0?oK
`Out(Hn
public void splitterStop() IvHh4DU3Z
{ =-KMb`xT
bStop = true; 8j5<6Cv_
} /ASaB
E<E3&;qD
HDVW0QaMu
} Z(u5$<up
~YP Jez
X(A.X:"
/* S0d~.ah30
**FileAccess.java {2&m`Dbm
*//文件访问(定位，写) JIm4vS
package NetFox; T!RT<&
import java.io.*; 1PH:\0}
ke_[
j}1zdA
public class FileAccessI implements Serializable{ mYxyWB
dq\FBwfe
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6at1bQ$
RandomAccessFile oSavedFile; bWWXc[O2&(
long nPos; %FZ2xyI.
{ZU1x C
.zg8i_
public FileAccessI() throws IOException 7O5`v(<9n>
{ 5U`ZbG
this("",0); oF]cTAqhC.
} |re}6#TgcT
2P#=a?~[
#KxbM-1=
public FileAccessI(String sName,long nPos) throws IOException e~l#4{w
{ ;U9J++\d<A
oSavedFile = new RandomAccessFile(sName,"rw"); 5xCT~y/a
this.nPos = nPos; 8:=n*
oSavedFile.seek(nPos); +Hvc_Av''
} P{OAV+cG
T9W`?A
rxnFrx
public synchronized int write(byte[] b,int nStart,int nLen) p)aeH`;O
{ #Z+i~t{e(
int n = -1; fhPkEvJ
try{ Sr?#wev]rn
oSavedFile.write(b,nStart,nLen); ]\-^>!F#K
n = nLen; Q?b14]6im
} Fm\"{)V:b
catch(IOException e) in+}/mwfC
{ x8Loyt_C
e.printStackTrace (); {S/yL[S.
} KWAb-yB
7ELMd{CD
C%d_@*82
return n; `Z:R Ce^
} 3@+b}9s8
hu_ ^OlF
}%b;vzkG5
} 7SDFz}
PyVC}dUAX
%^sTU4D5
/* 1"Z@Q`}
**SiteInfoBean.java 4iAZ+l5&
*/ 'c2W}$q
package NetFox; De7Ts
=4V&*go*\
*B`Zq)
public class SiteInfoBean { gE#>RM5D
4[Z\ ?[
glDcUCF3
private String sSiteURL; //Site's URL v+p{|X-
private String sFilePath; //Saved File's Path 0a8/B>
private String sFileName; //Saved File's Name {3;AwhN0H
private int nSplitter; //Count of Splited Downloading File &'cL%.
vEf4HZ&w
hfpJ+[
public SiteInfoBean() XL#[%X9
{//nSplitter的缺省值为5 {{V8;y
//default value of nSplitter is 5 %CWPbk^
this("","","",5); ^`un'5Vk
} w=b)({`M
f#+el y
3bO(?l`3h
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) BA\/YW @
{ DZzN>9<)^
sSiteURL= sURL; l/;X?g5+
sFilePath = sPath; :0Z^uuk`gq
sFileName = sName; ?X@fKAj
this.nSplitter = nSpiltter; n]8<DX99Q0
%X#zj"
:#dE:L;T
} 2,ECYie^
)`^p%k
6'\6OsH
public String getSSiteURL() %%(R@kh9
{ G\|,5HED
return sSiteURL; s4&^D<
} zD?oXs
rG,5[/l
LYlDc;<A
public void setSSiteURL(String value) UK9@oCIB
{ \fr-<5w79
sSiteURL = value; ^C2\`jLMY
} gV&z2S~"
+`?Y?L^ J
WJI[9@^I~
public String getSFilePath() pr%nbl
{ \u6^Varw
return sFilePath; /}-CvSR
} ^vG8#A}]
gZ5[ C
>0Q|nCx
public void setSFilePath(String value) ~]ZpA-*@Ut
{ N !TW!
sFilePath = value; MZmb`%BZ
} R|i/lEq
Da"j E
<n3!{w3<
public String getSFileName() C6rg<tCH
{ NcY608C
return sFileName; B"%{i-v>**
} @?h/B=56
6uKTGc4
Jx'i2&hGN
public void setSFileName(String value) M'_9A
{ Tw +
sFileName = value; `xrmT t X
} m3o,@=b
W_0>y9?
\>Efd
public int getNSplitter() /lafve~
{ y\&>ZyOY
return nSplitter; np~~mdmRK
} V2N_8)s9W
PfkrOsV/m
28 3H
public void setNSplitter(int nCount) ~F1:N>>_Cf
{ j(~ *'&|(
nSplitter = nCount; (%`QhH
} k__$Q9qj(
} /T.KbLx~q
NV#FvM/#"
r-h#{==*c
/* .L~Nq%g1
**Utility.java j2 !3rI
*/ cV`E>w=D0
package NetFox; RQMEBsI}
JMTvSXr
n8.kE)?
public class Utility { SXt{k<|
Bn!$UUC
[d* ~@P
public Utility() _v* nlc
{ j) ,,"54*
%TsPyiYl
[CAR[ g&
} , lJv
JsotOic%
//线程睡眠 /EG~sRvl}
public static void sleep(int nSecond) HI@syFaJM
{ DLCkM*'
try{ 5Vi>%5A>l
Thread.sleep(nSecond); B<-kzt
} Uo-`>7
catch(Exception e) pC_O:f>vJ
{ nVJPR
e.printStackTrace (); 6)BR+U
} J+f!Ar
} WKSPBT;
"]\+?
//日志 mA{~PpSb
public static void log(String sMsg) [xKd7"d/n
{ h`3eu;5)
System.err.println(sMsg); a<fUI%_
} 8|$3OVS
Ka,^OW}<%q
B4]`-mahO
public static void log(int sMsg) ]~\sA
{ y9KB< yh/
System.err.println(sMsg); l9M0cZ,
} <r3J0)r}
} JCW\ *R
kHqztg
%e@#uxm
/* pT$f8xJ
**TestMethod.java !\g+8>
*/ Zc?ppO
package NetFox; :f$xQr4Qz
uB7 V?A
bb d.
public class TestMethod { %sRUh0AL
|c`w'W?C6
(L`j0kPN
public TestMethod() ;m2<eS`o'
{ ///xx/weblogic60b2_win.exe rSYi<ku
try{ BT@r!>Nl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _A0w[n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;vb8G$
SiteFileFetch fileFetch = new SiteFileFetch(bean); TB;o~>9U
fileFetch.start(); 0VK-g}"x
} x\Y $+A,P
catch(Exception e){e.printStackTrace ();} 5xOvY
VAXT{s&4>
u_).f<mUdF
} {f{ZHi|
x=#VX\5k:
r `eU~7
public static void main(String[] args) l (3bW1{n
{ Xj*vh m%i
new TestMethod(); U!m@DJj
} n k2om$nN
} q5L51KP2
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