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)); [t{ed)J
} #"PRsMUw
for(int i=0;i<nEndPos.length-1;i++) =QG0:z)K<v
{ {=Y3[
nEndPos = nStartPos[i+1]; 'P`L?/_3
} wI{ED
nEndPos[nEndPos.length-1] = nFileLength; 6@X j
} O_~vl m<#
} C)H1<Br7
+\D?H.P
"Vw;y+F}
//启动子线程 WU:r:m+ >
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; VNggDKS~K
for(int i=0;i<nStartPos.length;i++) :enmMB#%
{ ? CabVj-r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OZCbMeB{+J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), IPTEOA<M[
nStartPos,nEndPos,i); q\I2lZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9FKowF_8
fileSplitterFetch.start(); PKK18E}{%^
} %=G*{mK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 15)y]N={^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lDU@Q(V#}<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ojwhcb^
nEndPos = " + nFileLength); iH;IXv,b3
// fileSplitterFetch[nPos.length-1].start(); =)O%5<Lwx
Y5&mJp\G
o)U4RY*
//等待子线程结束 H%&e[PU
//int count = 0; 24; BY'
//是否结束while循环 gQ8FjL6?
boolean breakWhile = false; x[m&ILr
I}!ErV
E4;@P']`
while(!bStop) :,~]R,tJQ
{ 7wA.:$
write_nPos(); 5;4bZ3e,0
Utility.sleep(500); (imaL,M-D
breakWhile = true; R{0nk
4],*y`& g
6$*\%
for(int i=0;i<nStartPos.length;i++) ^:Hx.
{ gd=gc<zYP
if(!fileSplitterFetch.bDownOver) a}#8n^2
{ D>>?8a
breakWhile = false; rd\:.
break; iQ7S*s+l5O
} 56JvF*hP
} G Ch]5\
if(breakWhile) -&UP[Mq
break; []#>r k~
=TcT`](o
y<0RgG1qp
//count++; NJqjW
//if(count>4) !\(j[d#
// siteStop(); %7vjYvo>
} Jp#Onl+d6
@5tW*:s
s/cclFji]
System.err.println("文件下载结束！"); =IC cN|
} R/BW$4/E
catch(Exception e){e.printStackTrace ();} w /l\p3n
} k&dLg5O
!STa}wl
%jc"s\
//获得文件长度 ROWrkJI>i
public long getFileSize() E{B8+T:3
{ Zp'q;h_
int nFileLength = -1; K>_~zWnc
try{ |tVWmm^m
URL url = new URL(siteInfoBean.getSSiteURL()); c1>:|D7w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eCfy'US;@3
httpConnection.setRequestProperty("User-Agent","NetFox"); iI 4XM>`a
^h^\kW'#
FQp@/H^
int responseCode=httpConnection.getResponseCode(); 7JL*y\'
if(responseCode>=400) ~bsL W:.'
{ CA8N
processErrorCode(responseCode); S`?L\R.:
return -2; //-2 represent access is error 6U!zc]>
} ^U@-Dp,k+
Mb +
q8-*3K
String sHeader; //O9}-
Ku3/xcu:My
o / i W%
for(int i=1;;i++) jph"94
{ 5U[bn=n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7~H.\4HB
//Utility.log(in.readLine()); YuVg/ '=
sHeader=httpConnection.getHeaderFieldKey(i); ^.:dT?@R
if(sHeader!=null) 8-clL\bm
{ Uk0Fo(HY
if(sHeader.equals("Content-Length")) \]$TBN dJ4
{ $ytlj1.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c'Mi9,q
break; bayDdR4T
} E!SxO~
} g71|t7Q
else 16Gp nb
break; 1*vt\,G
} wB0Ke
} >/eV4ma"
catch(IOException e){e.printStackTrace ();} EDAVU
catch(Exception e){e.printStackTrace ();} y%NZ(Y,v
=T3O;i
p+7ZGB
Utility.log(nFileLength); PYPDK*Ie
UL<*z!y
oy< q;'
return nFileLength; zhW.0:9 CR
} fJ8Q\lb<_
!c#~g0H+
A!n)Fpk
//保存下载信息（文件指针位置） DwBKqhu
private void write_nPos() gT8%?U:
{ b$O1I[o
try{ tIJ?caX5=
output = new DataOutputStream(new FileOutputStream(tmpFile)); `j1(GQt
output.writeInt(nStartPos.length); ?V>{3
for(int i=0;i<nStartPos.length;i++) ;c;5O@R}3
{ ouO<un
// output.writeLong(nPos); DuzJQSv
output.writeLong(fileSplitterFetch.nStartPos); Y%"73.x
output.writeLong(fileSplitterFetch.nEndPos); }+3v5Nz;
} tJgo%P1
output.close(); @Q#<-/
} ,'>,N/JA
catch(IOException e){e.printStackTrace ();} 3<vw#]yL
catch(Exception e){e.printStackTrace ();} pjaDtNb
} JrhDqyk*
hDAxX=FM
}2CVA.Qm!
//读取保存的下载信息（文件指针位置） Th%2pwvER
private void read_nPos() OEwKT7CX
{ q\q8xF~[p
try{ .*acw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x+B7r&#:
int nCount = input.readInt(); )xPfz
nStartPos = new long[nCount]; "1X@t'H38
nEndPos = new long[nCount]; gI5"\"T{
for(int i=0;i<nStartPos.length;i++) 8"5^mj
{ B+Ox#[<75
nStartPos = input.readLong(); C_q@ixF{
nEndPos = input.readLong(); B4d\4S_r%
} NL7CeHs5
input.close(); DuV@^qSbG.
} AQR/nWwx
catch(IOException e){e.printStackTrace ();} "oc&uj
catch(Exception e){e.printStackTrace ();} IJz=SV
} }_[Bp
[l%6wIP&{
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private void processErrorCode(int nErrorCode) -w#*~Q{'*
{ 8n`O{8:fi
System.err.println("Error Code : " + nErrorCode); Bk)*Z/1<x
} [<H'JsJl
|^!
GR ^d/
//停止文件下载 AFN"#M
public void siteStop() wr+r J
{ "S ~(|G
bStop = true; 5q Y+^jO]o
for(int i=0;i<nStartPos.length;i++) !\RBOdw C
fileSplitterFetch.splitterStop(); u:[vqlU
0S}ogU[k
/rQ[Ik$|
} \ =(r6X
} zFpM\{`[g
//负责部分文件的抓取 G:k]tZ*`
**FileSplitterFetch.java ugT;NB
*/ M,V~oc5
package NetFox; 5S&'O4yz^
D Xjw"^x
ytkV"^1^
import java.io.*; ~EJ+<[/
import java.net.*; We51s^(
qS.TVNZ
Q#a<T4l
public class FileSplitterFetch extends Thread { :l/?cV;
g(`m#&P>G
LLlt9(^d
String sURL; //File URL }>T$2"pf
long nStartPos; //File Snippet Start Position R_|Sg
long nEndPos; //File Snippet End Position a"6AZT"8
int nThreadID; //Thread's ID riuG,$EX
boolean bDownOver = false; //Downing is over Utv#E.VI
boolean bStop = false; //Stop identical :#I7);ol
FileAccessI fileAccessI = null; //File Access interface \4qwLM?E^
~,jBm^4
C[0*>W8o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException byrK``f
{ M`jqUg
this.sURL = sURL; oI2YJ2?Je8
this.nStartPos = nStart; 5OS|Vp||b
this.nEndPos = nEnd; xQ{n|)i>
nThreadID = id; |yT-N3H@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 AXmW7/Sj"
} ,-[e{=Cz
H,Ik&{@j
F[HMX4
public void run() yCt,-mz!z
{ RD1N@sHDKc
while(nStartPos < nEndPos && !bStop) #;*0 Pwe`
{ qC;1ND
]u\K}n6[q
GI ~<clhf
try{ C>bd HB7
URL url = new URL(sURL); tn@MOOPl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^qgOgu
httpConnection.setRequestProperty("User-Agent","NetFox"); p(J,fus
String sProperty = "bytes="+nStartPos+"-"; (Z{&[h
httpConnection.setRequestProperty("RANGE",sProperty); *pMu,?uE
Utility.log(sProperty); <XAW-m9SC
W{6%Hhp
djGzJLH
InputStream input = httpConnection.getInputStream(); +2WvGRC
//logResponseHead(httpConnection); H/Wo~$
I<v:xTor
-kZOve|5
byte[] b = new byte[1024]; P*M$^p
int nRead; T+9#&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =Y;w O8
{ E,fG<X{
nStartPos += fileAccessI.write(b,0,nRead); iR`c/
//if(nThreadID == 1) e.<y-b?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p"lTZ7c:Y
} 4Z"JC9As
vi:IO
Ev'BmDk
Utility.log("Thread " + nThreadID + " is over!"); _0uFe7sIZ
bDownOver = true; CG -^}xE:
//nPos = fileAccessI.write (b,0,nRead); dDeImSeV
} M:*^k
catch(Exception e){e.printStackTrace ();} ;K+'J0
} a*fUMhIi
} vxmz3ht,Q
OB&lq.r
\4B2%H
//打印回应的头信息 /'S@iq
public void logResponseHead(HttpURLConnection con) n,.ZLuBEX
{ 4Em$L]7
for(int i=1;;i++) +d=cI
{ |i-d#x8
String header=con.getHeaderFieldKey(i); B > sTM
if(header!=null) ?cF-w!>o8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |x[zzx# >-
Utility.log(header+" : "+con.getHeaderField(header)); 5m e|dvk
else 4jyDM68i
break; Le*sLuxk<
} E}*
} @aX$}
~SWR|[
^I4/{,Ev
public void splitterStop() P<1ZpL
{ }/{G
bStop = true; BRu/pyxG
} mF|7:zSo
[nBdq"K
^{vf|zZ _
} /<\B8^yQ
tCw.wDq3=
6N^sUc0s
/* Gxj3/&]^Y
**FileAccess.java $G_,$U!
*//文件访问(定位，写) HalkNR-eEm
package NetFox; IQz:DJ
import java.io.*; z 5T_
^3qo%=i
cc"L> XoK
public class FileAccessI implements Serializable{ w,'"2^Cwy
Fa!6*K\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cnrS.s=
RandomAccessFile oSavedFile; `k>h2(@9S
long nPos; FK8GBkQ!
`(RQh@H
RH=Tu6i
public FileAccessI() throws IOException tc_D8Q_
{ c|s*(WljY
this("",0); ?4]#gCks
} x9c/;Q&m
:Y{aa1
$h({x~Oj9
public FileAccessI(String sName,long nPos) throws IOException N0D)d
{ <}^W9>u<
oSavedFile = new RandomAccessFile(sName,"rw"); GO=&
this.nPos = nPos; ikSm;.
oSavedFile.seek(nPos); E903T''s
} S @EkrC\4n
{APsi7HYBr
m _0D^e7#
public synchronized int write(byte[] b,int nStart,int nLen) %/86}DCfE?
{ ~m]sJpW<"
int n = -1; E27N1J+1
try{ 6+:Tv2
oSavedFile.write(b,nStart,nLen); RawK9K_1
n = nLen; 1>doa1
} x}w"2[fL
catch(IOException e) '}`|QJ
{ q=M\#MlL0'
e.printStackTrace (); q 16jL,i
} a!;]9}u7
@Gs*y1
78s:~|WB<{
return n; j:yQP#U
} rt7Ma2tK
NW.<v /?=,
J|orvnkK
} 09f:%!^u
5 W<\J
x<0-'EF/S
/* H?dmNwkPY
**SiteInfoBean.java PgKA>50a
*/ 1I?D$I>CV
package NetFox; }HM8VAH
lF:gQ]oc
6z^Kg~a
public class SiteInfoBean { 4{:W5eT!/
$II[b-X?S
YHVJg?H3
private String sSiteURL; //Site's URL O};U3=^0f
private String sFilePath; //Saved File's Path T;eA<,H
private String sFileName; //Saved File's Name Su<Ggv"
private int nSplitter; //Count of Splited Downloading File +TzF*Np
|P_\l,f8`
?UXKy
public SiteInfoBean() (l28,\Bel
{//nSplitter的缺省值为5 cT8`l!RD<
//default value of nSplitter is 5 qsB,yckml
this("","","",5); ~ caKzq
} wAr (5nEbx
?fog 34g
&CvNNDgrJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U&fOsx?"
{ U/ncD F%C
sSiteURL= sURL; cxTP4\T\E
sFilePath = sPath; rz]0i@ehv'
sFileName = sName; &^ sgR$m
this.nSplitter = nSpiltter; >K{/Jx&
+Xi#y}%
apxZ}
} zMfr`&%e
`laaT5G\y
<a-I-~
public String getSSiteURL() Ni5~Buf
{ la ~T)U7
return sSiteURL; U!:Q|':=h
} D6iHkDTg
ti:qOSIDTA
7$(>Z^ Em
public void setSSiteURL(String value) 8K! l X
{ d}K"dr:W5
sSiteURL = value; SRl:+!@.
} |-N\?N9"
&zsaVm8
K2T&U$,
public String getSFilePath() vUGEzCM
{ N[%^0T$
return sFilePath; (F$V m
} l`L}*Q- 5
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+OFq=M
public void setSFilePath(String value) `A@{})+
{ iH& Izv
sFilePath = value; =T)4Oziks
} }/ 6Q3B
]HP aM
@O}%sjC1
public String getSFileName() *0)vsBi
{ 6(4FC?Y7
return sFileName; +'abAST t
} :\x)`lu
N"2Ire
JcEPwF.
public void setSFileName(String value) VnUWUIVJ
{ OWsK>egD
sFileName = value; ?5e:w?&g@
} 2f1WT g)
YEoQIR
xzg81sV7
public int getNSplitter() 'c 0]8Y4
{ 1 dT1DcZ
return nSplitter; n?*Fr sZ
} "nXL7N0
l~,5)*T
$LLkYOwI
public void setNSplitter(int nCount) A-\OB Nh
{ nwh7DUi
nSplitter = nCount; &MnS( 82L
} >3V{I'^^-
} $:V'+s4o
^)Xl7d|m+
~:r:?PwWG
/* * 8n0
**Utility.java ^9zL[R
*/ 6q ._8%
package NetFox; ${^WM}N
Hc1S:RW
:T(3!}4
public class Utility { H8+7rM
/t`s.!k
dieGLA<5_X
public Utility() won;tO]\;@
{ m@)~.E
s/+@o:
)(`I1"1
} XTpYf
F@Qzh
//线程睡眠 RnV )*
public static void sleep(int nSecond) E7-il;`cKn
{ g$<Sh.4A
try{ H(U`S
Thread.sleep(nSecond); 4(>|f_$
} K^j7T[pR
catch(Exception e) \EF^Ag
{ 4$LVl
e.printStackTrace (); UN'[sHjOnD
} 6('2.^8
} ?zW4|0
Vo^ i7
//日志 Pu dIb|V2
public static void log(String sMsg) ,h,DB=!K<
{ .$5QM&
System.err.println(sMsg); VWqmqR%
} .}Va~[0j
9~i=Af@
&GF@9BXI3
public static void log(int sMsg) zil^^wT0J
{ hw/:
System.err.println(sMsg); ]cvP !
} }t}y
} nen(
EYNi`
$'FPsoH
/* Y=+pz^/"
**TestMethod.java UfcQFT{()
*/ F}p)Q$0
package NetFox; ?S^ U-.`
rEEoR'c6
(D5 dN\
public class TestMethod { 8."B
2fIHFo\8
k I
public TestMethod() Q-<N)K$F(4
{ ///xx/weblogic60b2_win.exe ,TL8`
try{ S-{=4b'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zvjp]yTx"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *Ii_dpJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); wWjZXsOd
fileFetch.start(); #[$^M:X.
} 5Fa.X|R~
catch(Exception e){e.printStackTrace ();} Fq\vFt|m<
S"+X+Oxp7?
jroR2*
} 0;9X`z J
5=Cea
r]JV!'R
public static void main(String[] args) jpijnz{M
{ @@->A9'L
new TestMethod(); fS9TDy
} `5da
} 4mYJi#e6x
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