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)); 7"f$;CN?~
} `07u}]d8
for(int i=0;i<nEndPos.length-1;i++) fB5Bh;K
{ `4cs.ab
nEndPos = nStartPos[i+1]; z[Kxy1,
} SaEe7eHd
nEndPos[nEndPos.length-1] = nFileLength; RB_7S!qC5
} 0k5Zl?
} I~S`'()J
Z*kGWL
}>xgzhdT
//启动子线程 ~?vm97l
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Sv-}w$
for(int i=0;i<nStartPos.length;i++) |xH"Xvp:
{ L{~L6:6An
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @2 dp5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \%NhggS*
nStartPos,nEndPos,i); uLb- NxQ-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `sN3iD!@R
fileSplitterFetch.start(); _]tR1T5e
} %H-[u}s
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H/Goaf%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *6Rl[eXS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'oTcx Jx
nEndPos = " + nFileLength); m7kDxs(KO
// fileSplitterFetch[nPos.length-1].start(); P58U8MEG
n<CJx+U
@DkPJla&
//等待子线程结束 CBSJY&:K
//int count = 0; !j4C:L3F
//是否结束while循环 OP2!lEs
boolean breakWhile = false; )X\.Xr-6q
$7)O&T*q'
ER5Q` H
while(!bStop) 9;Wz;p
{ qB]z"Hfq,
write_nPos(); dWD,iO_"@
Utility.sleep(500); |gxU;"2`5~
breakWhile = true; Xk]5*C]6<
X@9_ukdpu
Oe$cM=Yf
for(int i=0;i<nStartPos.length;i++) p>K'6lCa
{ :M|c,SQK
if(!fileSplitterFetch.bDownOver) 5vbnO]8
{ >o 3X)
breakWhile = false; P xpz7He
break; 2I?HBz1v
} j#&sZ$HQ4
} =JO|m5z8>
if(breakWhile) 4g\a$7r
break; ]vQo^nOo
PBn(k>=+
r=L9x/r
//count++; qR]4m]o
//if(count>4) wc bs-arH
// siteStop(); 2y_rsu\
} J~gfMp.
f`A
T,7Y7MzF
System.err.println("文件下载结束！"); lu(G3T8
} (P`{0^O"}
catch(Exception e){e.printStackTrace ();} `yYgL@Zt
} Oku4EJFJ
//ZB B,[@
GeHDc[7
//获得文件长度 308w0eP
public long getFileSize() ?]9uHrdsN}
{ .[1A
int nFileLength = -1; h*%T2
try{ 7U.g4x|<
URL url = new URL(siteInfoBean.getSSiteURL()); d'[aOH4}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0E\R\KO$>
httpConnection.setRequestProperty("User-Agent","NetFox"); D<++6HN&#
Mh+'f 93
~O1*]
int responseCode=httpConnection.getResponseCode(); 0^E!P>
if(responseCode>=400) QwT]| 6>
{ 5)$U<^uy
processErrorCode(responseCode); +o'. !sRH
return -2; //-2 represent access is error o4~ft!>
} 3sp*.dk
34;c00
CdaB.xk
String sHeader; /mD KQ<
(sqS(xIY
)&dhE^ O
for(int i=1;;i++) cWRB=`=qz
{ HENCQ_Wra
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )&R;!#;5
//Utility.log(in.readLine()); ^G2vA8%
sHeader=httpConnection.getHeaderFieldKey(i); 3lL:vD5(
if(sHeader!=null) !%s7I^f*
{ Z:/S@ry
if(sHeader.equals("Content-Length")) Qgx~'9
{ W^=89I4]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); er#we=h
break; :>3&"T.
} M;iaNL(
} oC7#6W:@w
else :X4\4B*~
break; M9&tys[KX
} 8dA/dMQ
} GrQl3 Xi
catch(IOException e){e.printStackTrace ();} /pk;E$qv
catch(Exception e){e.printStackTrace ();} jQ^Ib]"K
bR8)s{p6
1|. 0]~0
Utility.log(nFileLength); +z[!]^H]4
.<NXk"\!y
!k s<VJh
return nFileLength; teB{GR
} _b5iR<f
@H_LPn
ZDDwh&h
//保存下载信息（文件指针位置） ,@!d%rL:4]
private void write_nPos() WX=+\`NyJ(
{ /uyQ>Y*-\Y
try{ 4Dd9cG,lN
output = new DataOutputStream(new FileOutputStream(tmpFile)); D$mrnm4d
output.writeInt(nStartPos.length); ffB]4
for(int i=0;i<nStartPos.length;i++) xK y<o
{ }jk^M|Z"Oz
// output.writeLong(nPos); >{??/fBd-
output.writeLong(fileSplitterFetch.nStartPos); {(q Un
output.writeLong(fileSplitterFetch.nEndPos); qt:->yiq+
} `nM4kt7
output.close(); _$cBI_eA7
} fZ376Z:S$
catch(IOException e){e.printStackTrace ();} 0[i]PgIH
catch(Exception e){e.printStackTrace ();} B}FF |0<
} R|M:6]}
s24H.>Z
$U0(%lIU
//读取保存的下载信息（文件指针位置） uf>w*[m5
private void read_nPos() >L;O, {Px-
{ l2v}PALs
try{ K5ph x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $I/p6
int nCount = input.readInt(); ueg X
nStartPos = new long[nCount]; iB,*X[}EqG
nEndPos = new long[nCount]; +]e4c;`ko}
for(int i=0;i<nStartPos.length;i++) ]e3nnS1*.
{ |kd^]!_
nStartPos = input.readLong(); <qy+@t
nEndPos = input.readLong(); 6\Z^L1973
} & vIKNGJ^
input.close(); a,E;R$[!
} n$?oZ*;
catch(IOException e){e.printStackTrace ();} }rQ*!2Y?
catch(Exception e){e.printStackTrace ();} G`P+J
} ;8v5 qz
'oEmbk8Hg
.=FJ5?:4i%
private void processErrorCode(int nErrorCode) [5 V
{ z7_./ksQ
System.err.println("Error Code : " + nErrorCode); d{m0uX56
} S-H3UND"
W!(Q_B
BxqCV%9o
//停止文件下载 Rta P+6'X
public void siteStop() p~b$+8#+
{ 19vD(KC<
bStop = true; Mzd}9x$'J
for(int i=0;i<nStartPos.length;i++) gf=*m"5
fileSplitterFetch.splitterStop(); \'KzSkC8
QezK&iJg
L!G3u/
} hJ@nW5CI
} ^v'Lu!\f
//负责部分文件的抓取 {8MF!CG]
**FileSplitterFetch.java 9x1Dyz 2?F
*/ Z4!3I@yZ
package NetFox; |eqDT,4
O(d'8`8
k$>T(smh
import java.io.*; pi{ahuI#_o
import java.net.*; + ThKqC_
72 6y/o
8xX{y#
public class FileSplitterFetch extends Thread { 40E[cGz$*
neBkwXF!
<*+MBF
String sURL; //File URL '$zFGq }}
long nStartPos; //File Snippet Start Position hMQaT-v
long nEndPos; //File Snippet End Position <b\urtoJ
int nThreadID; //Thread's ID MI}D%n*
boolean bDownOver = false; //Downing is over meWAm?8RI
boolean bStop = false; //Stop identical *8p</Q
FileAccessI fileAccessI = null; //File Access interface Vh8uE
iiTUhO )
e'Pa@]VaC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [ n2udV
{ +=_Pl7?
this.sURL = sURL; 7`}z7nk
this.nStartPos = nStart; ZS+2.)A
this.nEndPos = nEnd; q|l|gY1g)
nThreadID = id; ^bG!k]U!2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (G VGoh&
} )3AT=b
i@* ^]'
#O WSy'Qnt
public void run() [;I8ZVE
{ [oj"Tn(
while(nStartPos < nEndPos && !bStop) SXEiyy[7v
{ z#4g,)ZX
7'S]
=-qsz^^a-
try{ v`&Z.9!Tz^
URL url = new URL(sURL); x_K%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~#CCRUhM
httpConnection.setRequestProperty("User-Agent","NetFox"); J (h>
String sProperty = "bytes="+nStartPos+"-"; 1%,Z&@^j
httpConnection.setRequestProperty("RANGE",sProperty); l_c?q"X
Utility.log(sProperty); lu_Gr=#O
CkU=0mcY
: [y(<TLw
InputStream input = httpConnection.getInputStream(); m"R(_E5
//logResponseHead(httpConnection); g8Z14'Ke
8##jd[o&p~
^U}0D^jDeE
byte[] b = new byte[1024]; o[#a}5Y
int nRead; z"3c+?2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (zBQ^97]
{ ={^#E?
nStartPos += fileAccessI.write(b,0,nRead); oK6lCGM5
//if(nThreadID == 1) tOw 0(-:iq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S2)S/ nf
} _LNPB$P
7;NV 1RV
^&iV%vQ[
Utility.log("Thread " + nThreadID + " is over!"); u*{ _WL[(
bDownOver = true; }H=OVbQor
//nPos = fileAccessI.write (b,0,nRead); (Y([^N q
} {P&^Erx
catch(Exception e){e.printStackTrace ();} o2
} wY#mL1dF
} ydQS"]\g
16|S 0 )
d]EvC>
//打印回应的头信息 .TC `\mV
public void logResponseHead(HttpURLConnection con) sd53 _sV
{ w|C~{
for(int i=1;;i++) aB^G
{ t5h_Q92N
String header=con.getHeaderFieldKey(i); Z<W6Avr
if(header!=null) E6:p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^A`(
Utility.log(header+" : "+con.getHeaderField(header)); M;qL)vf
else 5H+k_U
break; lIg2iun[n
} Tm52=+uf$
} Q=E@i9c9
s~ A8/YoU}
%%6('wi
public void splitterStop() c'";36y
{ dH|^\IQ
bStop = true; e-9unnk
} C`wI6!
e6lOmgHn5
<R>z;2c
} 070IBAk}_
)1Nnn
RFY!o<
/* -G#k/Rz6
**FileAccess.java sG2 3[t8
*//文件访问(定位，写) E]U0CwFtr
package NetFox; `Xdxg\|
import java.io.*; -P>=WZu
:-La $I>
sdYj'e:N
public class FileAccessI implements Serializable{ MdZgS#`
dM{~Ubb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 AijTT%
RandomAccessFile oSavedFile; 1Uk~m
long nPos; 2F@)nh
d~-p;i
'%C.([
public FileAccessI() throws IOException [P=[hj;
{ o!`O i5
this("",0); ><Z3<7K9
} n~u3
{$YD-bqY
ih |Ky+!
public FileAccessI(String sName,long nPos) throws IOException e=sJMzm~
{ F*t_lN5{
oSavedFile = new RandomAccessFile(sName,"rw"); F'FZ?*a
this.nPos = nPos; x9"4vp
oSavedFile.seek(nPos); |qcFmy
} 2BX GVo
f&|A[i>g
(%yc5+f!
public synchronized int write(byte[] b,int nStart,int nLen) !]+Z%ed`%
{ 5!jNL~M
int n = -1; 6F.7Ws<
try{ nDB 2>J
oSavedFile.write(b,nStart,nLen); 1]Q2qs
n = nLen; #0hNk%X=
} "%''k~UD4
catch(IOException e) &4&33D
{ .#55u+d,
e.printStackTrace (); [Am`5&J
} |( 9#vt#
)S};k=kG
jS3(>
return n; F] ?@X
} 4UD=Y?zK
U?mf^'RE
a,*p_:~i
} i4zV(
Qy5Os?9"
D?yE$_3>c
/* H9VXsFTW
**SiteInfoBean.java |\|)j>[i
*/ ``|RO[+2
package NetFox; dMs||&|&
{{*]bGko
AXP`,H
public class SiteInfoBean { wp%FM
Fiu!!M6
;=+Zw1/g
private String sSiteURL; //Site's URL &49$hF g6"
private String sFilePath; //Saved File's Path +6hl@Fm(
private String sFileName; //Saved File's Name .^~l_LkA
private int nSplitter; //Count of Splited Downloading File u}}9j&^Xa
Z%5nVsm:G
g:DTVq
public SiteInfoBean() yvd `nV
{//nSplitter的缺省值为5 T3 9C lH
//default value of nSplitter is 5 X')Zm+
this("","","",5); MuoctW
} ;=-j;x
6L,lq;
R'I_xjC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hkwa""-
{ {!}F :~*r
sSiteURL= sURL; }\f(qw
sFilePath = sPath; G_M:0YI@
sFileName = sName; QGr\I/Y
this.nSplitter = nSpiltter; 3g0u#t{
HS\3)Ooj>
)?B~64N,+
} '9 e\.
&{E`=4T2
_jTwiuMS-
public String getSSiteURL() 9rTz N
{ _2m[(P9d
return sSiteURL; #~4{`]W6
} 4W!\4Va
j&dx[4|m:h
-jxWlO
public void setSSiteURL(String value) * {gxI<
{ dY/u<4
sSiteURL = value; +[whh
} 4e+BqCriC*
w53z*l>ek
}F{C= l2
public String getSFilePath() G(As%r]
{ GG_^K#*
return sFilePath; ,v*p
} *Mwfod
*H5PT
%6A-OF
public void setSFilePath(String value) <TR/ `
{ 7|QGY7Tf
sFilePath = value; 5#0A`QO
} 0R@g(
#vj#! 1
$ZI~8rI~
public String getSFileName() $5lW)q A
{ \Pl,' 1%
return sFileName; hdd>&?p3
} @PQrmn6w
5S%C~iB
R:w%2Y
public void setSFileName(String value) jCTy:q]
{ As@ihB+(\
sFileName = value; b/sOfQ
} Ecxj9h,S
{sC@N![
)L |tn
public int getNSplitter() bZ>&QM
{ YH[XRUa
return nSplitter; {*QvC g?
} T?X^0UdJj
$%g\YdC
>`7OcjLg
public void setNSplitter(int nCount) pi`;I*f/
{ ~`t%M?l
nSplitter = nCount; 5v|H<wPp
} zmf"I[)
} 3L%WVCB
,IIZXl@
i8Fs0U4"
/* 5<89Af&&K8
**Utility.java cMDRWh
*/ 2GSgG.%SSM
package NetFox; k)`$%[K8
!0Idp%
HEBqv+bG
public class Utility { \F 3C=M@:
M#OHY*
/Q?~Q0{)es
public Utility() }{ n\tzR
{ i?F[||O"$
=~J"kC
Ovvny$
} Z^s+vi
3->,So0Y
//线程睡眠 y7/PDB\he
public static void sleep(int nSecond) }0QN[$H!
{ k/G7.)C
try{ NEA_Plt
Thread.sleep(nSecond); 79D=d'eA
} E{uf\Fc
catch(Exception e) !w q4EV
{ 42fprt
e.printStackTrace (); Q[M (Wqg
} (lb6]MtTHY
} R6`*4zS
0$tjNye
//日志 Mx8Gu^FW.d
public static void log(String sMsg) On=u#DxQ
{ DU;[btK>
System.err.println(sMsg); I*Vt,JYx
} Bc@30KiQ^
<B!'3C(P
)ZGYhE
public static void log(int sMsg) R|iEvt
{ *B1x`=
System.err.println(sMsg); !"Qb}g
} C\ vC?(n
} {>@QJlE0
U^[<
%y>+1hakkX
/* =_[2n?9y
**TestMethod.java u?F (1iN=
*/ =p]mX)I_
package NetFox; )!e3.C|V1W
9 ~~qAoD
}|Uj"e
public class TestMethod { t05_Px!mW
RdgVBG#Z1
M#xQW`-`
public TestMethod() mzGjRl=O
{ ///xx/weblogic60b2_win.exe `mzb(bE
try{ 5SUN.%y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7{pIPmJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;K_}A4K
SiteFileFetch fileFetch = new SiteFileFetch(bean); f])M04<
fileFetch.start(); NPm;
} 9JPEj-3`g
catch(Exception e){e.printStackTrace ();} ocF>LR%P
_.{zpF=j
`FZF2.N
} mQ}Gh_'ps
kn}zgSO
{)xWD%
public static void main(String[] args) GW3>&j_!d
{ xYI;V7
new TestMethod(); .n`( X#,*l
} :?=Q39O9
} XA)'=L!^
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