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)); lfle7;
} Mp%.o}j
for(int i=0;i<nEndPos.length-1;i++) p }p@])}8
{ 4Z'/dI`
nEndPos = nStartPos[i+1]; blUnAu o~
} U,;a+z4\
nEndPos[nEndPos.length-1] = nFileLength; Z4&,KrV
} mNc?`G_R
} r)4GH%+?fv
?%QWpKO7X
[UP-BX(
//启动子线程 lKtA.{(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pZVT:qFF
for(int i=0;i<nStartPos.length;i++) 5mtsN#
{ nM=5L:d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s *8)|N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w)nFH)f
nStartPos,nEndPos,i); =sp5.-r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SC Qr/Q
fileSplitterFetch.start(); !Dc|g~km\
} V:YN!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bi@z<Xm%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LBcnBo</v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j3W)
nEndPos = " + nFileLength); xE.yh#?.k
// fileSplitterFetch[nPos.length-1].start(); y}\d]*5
ApT8;F B
h?8I`Z)h
//等待子线程结束 4Go$OQ`
//int count = 0; Ml"i^LR+
//是否结束while循环 z_;:6*l=:
boolean breakWhile = false; B IW?/^
y TbOBl
KxA^?,t[
while(!bStop) 5 R*
{ ?Q?=I,2bP
write_nPos(); oJ:\8>)9
Utility.sleep(500); .!oYIF*0zC
breakWhile = true; Xur{nk~?
gpvzOW/
qk+RZ>T<o
for(int i=0;i<nStartPos.length;i++) ep,"@,,
{ C>MEgGP
if(!fileSplitterFetch.bDownOver) p%ve1>c
{ VR'R7
breakWhile = false; GR%h3HO2&
break; XCo3pB Wq~
} VZhHO d
} d~|/LR5
if(breakWhile) 0gIJ&h6*f
break; ?q*,,+'0
PLV-De
$2kZM4
//count++; ;YfKG8(0
//if(count>4) :`Z'vRj
// siteStop(); m9Pzy^g1
} ,f[`C-\Q%
3*v&6/K
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System.err.println("文件下载结束！"); gP13n!7
} '(6 ^O=
catch(Exception e){e.printStackTrace ();} >V,i7v*?
} Z=I+_p_G
jYxmU8
B-.QGf8K.
//获得文件长度 VoGyjGt&
public long getFileSize() o-}q|tD$<
{ =/Lwprj
int nFileLength = -1; L>ruNw'-K
try{ #~JR_oQE!
URL url = new URL(siteInfoBean.getSSiteURL()); <@](uWu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n>o0PtGxC
httpConnection.setRequestProperty("User-Agent","NetFox"); o4U[;.?c
Z'<I Is:J
R'z -#*[
int responseCode=httpConnection.getResponseCode(); ir?Y>
if(responseCode>=400) =qNZ7>Qw
{ o9JZ-biH
processErrorCode(responseCode); iD(+\:E
return -2; //-2 represent access is error #;lB5) oe
} &Sr7?u`k
U4.-{.
Kqn{q4L
String sHeader; -qDM(zR
RAs5<US:
c_N'S_)~7Q
for(int i=1;;i++) {[[j.)
{ !uxma~ZH-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jTh^#Q
//Utility.log(in.readLine()); g.:b\JE`
sHeader=httpConnection.getHeaderFieldKey(i); kw$*o k
if(sHeader!=null) 9^zA(
{ oScKL#Hu
if(sHeader.equals("Content-Length")) tB<2mjg
{ @&F\M}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T!ik"YZ@i
break; a{y"vVQOF
} 0{k*SCN#
} 4f-I,)qCBk
else OBp&64
break; W*!u_]K>
} !C>'a:
} \)/dFo\l
catch(IOException e){e.printStackTrace ();} BK[ YX)
catch(Exception e){e.printStackTrace ();} M!#[(:
lDf:~
7.!`c-8 u
Utility.log(nFileLength); fEYo<@5c]
|K11Woii
?E|be )
return nFileLength; =K`]$Og}8
} wF.S ,|
*D:"I!Ho
_c@k>"_{S
//保存下载信息（文件指针位置） :OC(93d)0
private void write_nPos() J69B1Yi
{ yu98d1
try{ .8~zgpK
output = new DataOutputStream(new FileOutputStream(tmpFile)); [}1+=Ub
output.writeInt(nStartPos.length); ,enU`}9V*
for(int i=0;i<nStartPos.length;i++) =AVr<kP
{ vq_v;$9}
// output.writeLong(nPos); cq,8^o&
output.writeLong(fileSplitterFetch.nStartPos); <ZwmXD.VD
output.writeLong(fileSplitterFetch.nEndPos); 7zWr5U.
} 8(kP=
output.close(); G8hq;W4@]/
} Uoqt
catch(IOException e){e.printStackTrace ();} wx*)7Y*
catch(Exception e){e.printStackTrace ();} o8h1
} /q\{OsrX
iO2%$Jw9\
/t;Kn m
//读取保存的下载信息（文件指针位置） E#^?M#C
private void read_nPos() w.0:#4
{ fo5+3iu^
try{ 7TaHE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7w8I6
int nCount = input.readInt(); F =Zc_
nStartPos = new long[nCount]; A{(<#yRfg
nEndPos = new long[nCount]; *0!IHr"fn
for(int i=0;i<nStartPos.length;i++) ,EuJ0]2
{ SBog7An9SI
nStartPos = input.readLong(); o?]g
nEndPos = input.readLong(); U|YIu!^
} Au[H!J
input.close(); ry[NR$L/m
} P+s-{vv{0
catch(IOException e){e.printStackTrace ();} r_?il]l
catch(Exception e){e.printStackTrace ();} E2xcd#ZD
} h}@)oSX }
ztG!NZL
)gb gsQZ
private void processErrorCode(int nErrorCode) N8K @ch3=P
{ 50VH>b_
System.err.println("Error Code : " + nErrorCode); *E1v
} Q ,6[
{I"`(
9! 6\8
//停止文件下载 mO~A}/je
public void siteStop() 6d%'>^`(o-
{ [T>a}}@
bStop = true; |8<P%:*N
for(int i=0;i<nStartPos.length;i++) 0//B+.#
fileSplitterFetch.splitterStop(); tc4"huG
TLC&@o :
#5a'Z+
} l;'#!hC)
} p#6V|5~8
//负责部分文件的抓取 d%C:%d
**FileSplitterFetch.java Ad'b{C%
*/ kIlK"=
package NetFox; ;+W9EbY2
gyx4='Q
:4'Fq;%C
import java.io.*; =m6yH_`@
import java.net.*; yccF#zU
\Tii S
4Bc<
public class FileSplitterFetch extends Thread { B6hd*f
n>-"\cjV
^+)q@{\8Y
String sURL; //File URL Gi*GFv%xB
long nStartPos; //File Snippet Start Position wEp*j+Mmce
long nEndPos; //File Snippet End Position mE+
int nThreadID; //Thread's ID Pcox~U/j
boolean bDownOver = false; //Downing is over NIascee
boolean bStop = false; //Stop identical xw5LPz;B
FileAccessI fileAccessI = null; //File Access interface M!nwcxB!
leMcY6
-g`3;1EV^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z-wvdw]$
{ ZZJXd+Q}
this.sURL = sURL; ;s(uaC3
this.nStartPos = nStart; v@KP~kp
this.nEndPos = nEnd; 5Rc^5Nv
nThreadID = id; 48 |u{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 e_{!8u.+
} 7HkQ|~zGT
Tl2e?El;4
A0hfy|1#L
public void run() w:~Y@b~D
{ ,O[Maj/ch
while(nStartPos < nEndPos && !bStop) 4X^{aIlshk
{ _#mo6')j
v7kR]HU[y
sKLH.@
try{ S7_^E
URL url = new URL(sURL); ^3:y<{J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5f'<0D;K
httpConnection.setRequestProperty("User-Agent","NetFox"); C1YG=!
String sProperty = "bytes="+nStartPos+"-"; xU5+"t~
httpConnection.setRequestProperty("RANGE",sProperty); *[MK{m
Utility.log(sProperty); !o k6*m
Gd08RW
m=7Z8@sX},
InputStream input = httpConnection.getInputStream(); vKCgtk
//logResponseHead(httpConnection); !R/-|Kjy
lxvRF93a.
$4j$c|S!
byte[] b = new byte[1024]; Q'mLwD3>
int nRead; y_Tc$g~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) S5$sB{\R
{ D#?jddr-
nStartPos += fileAccessI.write(b,0,nRead); ju= +!nGUa
//if(nThreadID == 1) >.]'N:5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v1E=P7}\{s
} djxM/"xo
|0jmOcZF
!^/Mn
Utility.log("Thread " + nThreadID + " is over!"); ZX Sl+k.
bDownOver = true; p>c`GDU
//nPos = fileAccessI.write (b,0,nRead); 8!c#XMHV
} W6>SYa
catch(Exception e){e.printStackTrace ();} .;'3Roi
} t=;84lA
} X%>Sio
~il{6Z+#n
Wveba)"$
//打印回应的头信息 ydyGPZt
public void logResponseHead(HttpURLConnection con) L`!M3c@u
{ i47xF7y\
for(int i=1;;i++) O!c b-
{ ERE1XOe=D
String header=con.getHeaderFieldKey(i); /W,K% s]
if(header!=null) O73 /2=1V
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {MaFv
Utility.log(header+" : "+con.getHeaderField(header)); 3Q@HP;<
else TBzOz:k
break; }uTe(Rf
} $YM6}D@
} +C(v4@=nd
vGT#BS%
Du3nK"-g
public void splitterStop() :gNTQZR
{ {Va"o~io
bStop = true; $YyN-C
} F9|\(St &
+[DL]e]@U
bS9<LQ*
} ~ }<!ON;
^.d97rSm
nsCat($)
/* r.V< 5xV
**FileAccess.java }5)sS}C
*//文件访问(定位，写) Z!qHL$
package NetFox; i'Oh^Y)E#
import java.io.*; :.+?v*%;n
aFj)s?$4]K
(v\Cv)OS
public class FileAccessI implements Serializable{ ![v@+9
w;;.bz m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -cjwa-9 ~
RandomAccessFile oSavedFile; _TRO2p0
long nPos; c==` r C
6L~tUe.G
J)w58/`?t
public FileAccessI() throws IOException l9J]<gG
{ nj7wc9z4
this("",0); z'G~b[kG4n
} 2{!^"iW
4gTDHQP
}- Jw"|^W
public FileAccessI(String sName,long nPos) throws IOException DJtKLG0
{ ;(kU:b|j
oSavedFile = new RandomAccessFile(sName,"rw"); l+>&-lX'
this.nPos = nPos; ?T\m V}
oSavedFile.seek(nPos); l"\W]'T:r
} \gh`PS-B
WrR97]7t
@+v;B:
public synchronized int write(byte[] b,int nStart,int nLen) [>'P
{ 1!x-_h}
int n = -1; dJhT}"x
try{ EcA@bZ0
oSavedFile.write(b,nStart,nLen); ?w}E/(r
n = nLen; *CA7 {2CX
} Ba$Ibq,r/
catch(IOException e) #K3A{ jb,
{ a;a2x .<
e.printStackTrace (); CaZ{UGokL
} ccWz,[
p2|BbC\N
EH'?wh|Yp
return n; "e4hPY#
} w%no6 ;
{=AK|
iB Ld*B|#K
} GRanR'xG
J^@0Ff;=5^
EV:y}
/* ("t; 2Mw
**SiteInfoBean.java c1IK9X*
*/ ])=k";76
package NetFox; *q8L$D
.TN9N
hi>sDU<x
public class SiteInfoBean { <}c`jN!z.
<y(uu(c
Fejs9'cB
private String sSiteURL; //Site's URL X*2MNx^K~
private String sFilePath; //Saved File's Path silTL_$
private String sFileName; //Saved File's Name xGQ958@
private int nSplitter; //Count of Splited Downloading File MorR&K
D?u*^?a2
[~;#]az
public SiteInfoBean() lc%2Pi[X
{//nSplitter的缺省值为5 SC~cryb
//default value of nSplitter is 5 Ks.pb !r
this("","","",5); K8.=bGyg
} V~+{douq
6g*B=d(j
cH()Ze-B
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yfS`g-j{~
{ jXO*_R
sSiteURL= sURL; -WIT0F4o;
sFilePath = sPath; 1.]Py"@:
sFileName = sName; $/%|0tQ
this.nSplitter = nSpiltter; jUq^$+N
/@5X0m
#c5 NFU}9
} C3af>L@}
=GpO}t">
a;eV&~
public String getSSiteURL() Kc=&jCn
{ tVUoUl
return sSiteURL; .y{qsL^P
} fbKL31PI
uj$b/I>.'
~_P,z?
public void setSSiteURL(String value) '&5A*X]d
{ xp%,@]p
sSiteURL = value; mnM#NT5]
} 8t!/Op?
^tIi;7k
"E;]?s9x
public String getSFilePath() j_E$C.XU{g
{ T<\Q4Coth
return sFilePath; 2G8f4vsC[
} !Y3w]_x[:
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~S)o('
public void setSFilePath(String value) B*A{@)_
{ 0+b1R}!2
sFilePath = value; C8%Iol
} 83UIH0(
d-g&TSGd
2H8,&lY.p
public String getSFileName() F8km8lPQl
{ X8Px
return sFileName; =&~*r
} o'@VDGS`
vV:eU-a
jE.U~D)2YF
public void setSFileName(String value) 9u/"bj
{ r5z_{g
sFileName = value; %N@454enH
} [k(oQykq
c *(]pM
+Sk;
public int getNSplitter() \+mc
{ |s :b9sfA
return nSplitter; m M!H}|
} ba^cw}5
[G^ir
[1@-F+
public void setNSplitter(int nCount) `#hdb=3
{ 6;U]l.
nSplitter = nCount; 4f<%<Z
} \3(d$_:b
} {w.rcObIw+
5An|#^]
MzRURH,
/* @2-Eky
**Utility.java PZ~uHX_d>
*/ *Z=K9y,IC
package NetFox; 4flyV -
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3!^5a%u
public class Utility { ?fDF Rms
a?CV;9
2xH9O{
public Utility() Ob2H7!
{ Af5O;v\
zlIXia5
dL'hC#!h
} VL"!.^'c
"; tl>Ot
//线程睡眠 >bWsUG9
public static void sleep(int nSecond) iIu
{ MNOT<(
try{ ce&)djC7U
Thread.sleep(nSecond); 1 ry:Z2
} 09`5<9/
catch(Exception e) DYJ@>8
{ J]5sWs
e.printStackTrace (); zr%lBHuW
} #q40 >)]
} ?"\`u;
vbzeabm
//日志 ipnvw4+
public static void log(String sMsg) .?9+1.`
{ ?c0OrvM
System.err.println(sMsg); a02;Zl
} ?as)vYP
KHKf+^uu
x(h(a#,r
public static void log(int sMsg) D+d\<":
{ +Ck F#H ~
System.err.println(sMsg); Qfr%BQV
} rxjMCMF
} ^Afq)26D
|&WeXVH E
$+)2CXQe5
/* ;|e{J$
**TestMethod.java qYc]Y9fi
*/ 72@raA#y
package NetFox; 4UmTA_& Io
LF?83P,UJ#
Ks:~Z9r}
public class TestMethod { >up'`K,
pXPwn(
J6/Mm7R
public TestMethod() RRig
{ ///xx/weblogic60b2_win.exe X6%w6%su5
try{ [TvH7ott'1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xjc{={@p3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JyWBLi;Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); DesvnV'{`
fileFetch.start(); %m1k^
} c%c/mata?
catch(Exception e){e.printStackTrace ();} (-DA%
(nfra,'
+lmMBjDa
} u}hQF$a"
}2-<}m9}
O= PFr"
public static void main(String[] args) #+p30?r0y
{ Lzu;"#pw
new TestMethod(); |BhfW O8p
} f~-81ctu
} IO~d.Ra
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