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)); X0Xs"--}
} %0$$tS +
for(int i=0;i<nEndPos.length-1;i++) q<D'"7#.
{ ![{>f6{J
nEndPos = nStartPos[i+1]; ()=
} N3 07lGb
nEndPos[nEndPos.length-1] = nFileLength; :74)nbS
} ;~#rdL
} qZG "{8
vfcj,1
!1w=_
//启动子线程 *<"xF'C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Xr6UN{_-
for(int i=0;i<nStartPos.length;i++) _{C:aIl[2
{ yzgDdAM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O-}{%)[ F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YeptYW@xfw
nStartPos,nEndPos,i); E@Q+[~H}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j#Bea ,
fileSplitterFetch.start(); +8v^J8q0
} 11Pm lzy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]'EtLFv)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4{[Df$'e>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qOqQt=ObU
nEndPos = " + nFileLength); w=e~ M
// fileSplitterFetch[nPos.length-1].start(); WENPS*0oS]
-*M/,O
A +e ={-*
//等待子线程结束 8{(;s$H~
//int count = 0; p\WW~qD
//是否结束while循环 yL7a*C&
boolean breakWhile = false; gj0gs
R<a7TkL4?
RxjC sjg
while(!bStop) v<HhB.t.
{ K8ecSs}}J
write_nPos(); b'3w.%^
Utility.sleep(500); (/-2bO
breakWhile = true; B9&"/tT
~?H _?}e
~(~fuDT~O
for(int i=0;i<nStartPos.length;i++) {I&>`?7.
{ -;Y*;xe
if(!fileSplitterFetch.bDownOver) b(wW;C'#0p
{ 9EIHcUXe
breakWhile = false; D[-V1K&g
break; 7D@O:yO
} >Ke4lO"
} F)z]QJOw
if(breakWhile) N~=p+Ow[H
break; ts<5%{M(
CC;T[b&
c0sU1:e0
//count++; t$m268m~
//if(count>4) y9cW&rDH
// siteStop(); kid3@
} Cdin"
N2 wBH+3w
"M3R}<Vt
System.err.println("文件下载结束！"); }*4XwUM e
} D'$ki[{,
catch(Exception e){e.printStackTrace ();} MN}@EQvW==
} &}_E~jKK
}S\\"SBC
}Dc0 Y
//获得文件长度 b%IRIi&,
public long getFileSize() m-xSF]q=<
{ p-POg%|&<
int nFileLength = -1; LBh|4S$K
try{ @T0F }(k
URL url = new URL(siteInfoBean.getSSiteURL()); "t$c'`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F4xYfbwY"]
httpConnection.setRequestProperty("User-Agent","NetFox"); UA>UW!I
Mj&q"G
D(yU:^L
int responseCode=httpConnection.getResponseCode(); PHU#$LG
if(responseCode>=400) O8%+5l`T!
{ =;#+8w=^
processErrorCode(responseCode); 3xj ?}o
return -2; //-2 represent access is error Ikv@}^p 7
} Uo>pV9xRG
80TSE*
52 ?TLID
String sHeader; 9lbe[w@
/GCI`hx>"
ebxpKtEC
for(int i=1;;i++) (RW02%`jjy
{ iG()"^G
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &ejJf{id
//Utility.log(in.readLine()); !ba /]A/
sHeader=httpConnection.getHeaderFieldKey(i); Cbv$O o*
if(sHeader!=null) #EQwl6
{ u/-ul
if(sHeader.equals("Content-Length")) d:cs8f4>
{ 2+y<&[A8U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ];P$w.0
break; 1$2'N~`#U
} 9#Gz2u$
} biLx-F c
else }SpjB
break; -LI^(_
} 4iMo&E<
} \Ld/'Z;w
catch(IOException e){e.printStackTrace ();} CV&+^_j'k
catch(Exception e){e.printStackTrace ();} s ~c_9,JK
FRqJ#yd]
\0?^%CD+@
Utility.log(nFileLength); |)`<D
{>$i)B
o?%1^6&HE
return nFileLength; X%w`:c&
} lMoi5q
`/$yCXy
:$4 atm
//保存下载信息（文件指针位置） +0)s{?
private void write_nPos() \ t4:(Jp 3
{ O75^(keW
try{ @AET.qGC
output = new DataOutputStream(new FileOutputStream(tmpFile)); X!#rw= Q
output.writeInt(nStartPos.length); ,kS3Ioj
for(int i=0;i<nStartPos.length;i++) M+4>l\
{ [*^`rQ
// output.writeLong(nPos); "O@L IR7
output.writeLong(fileSplitterFetch.nStartPos); o,}`4_N||
output.writeLong(fileSplitterFetch.nEndPos); rV;X1x}l
} r1dP9MT\8
output.close(); ]U?)_P@}
} ,tqMMBwC~_
catch(IOException e){e.printStackTrace ();} 3Run.Gv\
catch(Exception e){e.printStackTrace ();} BSU%.tmI
} 8ExEhBX8
3<">1] /,
@)nxX))a
//读取保存的下载信息（文件指针位置） =*<Cw?Gc
private void read_nPos() m?wPZ^u
{ @Tk5<B3
try{ <=D!/7$O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ixc~DV+@[
int nCount = input.readInt(); G- nS0Kn:
nStartPos = new long[nCount]; %A_h!3f&
nEndPos = new long[nCount]; bn$a7\X-
for(int i=0;i<nStartPos.length;i++) ffDh0mDN
{ E$!0h_.(
nStartPos = input.readLong(); G?Fqm@J{XT
nEndPos = input.readLong(); $hv o^$
} qI (<5Wxl
input.close(); :K J#_y\rt
} )> >Tj7
catch(IOException e){e.printStackTrace ();} =@BVO@z@
catch(Exception e){e.printStackTrace ();} W>[0u3
} ;J<K/YdI
[H"\<"1o
mIk8hA@B_
private void processErrorCode(int nErrorCode) k/'>,WE
{ l}\q }7\)
System.err.println("Error Code : " + nErrorCode); &USKudXmb
} IXQxjqd^
i|M^QKvF
=Rv!c+?
//停止文件下载 Q)vf>LwC2S
public void siteStop() )o4B^kq
{ vSyR% j
bStop = true; O>FE-0rW}e
for(int i=0;i<nStartPos.length;i++) &?[uY5Mk
fileSplitterFetch.splitterStop(); "}/$xOl"
:<Z>?x
VAGQR&T?
} Lmp_8q-Ej
} C|or2
//负责部分文件的抓取 #>[BSgW
**FileSplitterFetch.java .r=F'i}-j*
*/ _o,Mji|
package NetFox; 0Z{;sW
60RYw9d%0
Ep }{m<8c
import java.io.*; ^)wTCkH&y
import java.net.*; [yFf(>B
8Qm%T7]UFb
e#{,M8
public class FileSplitterFetch extends Thread { ?7?hDw_Nk
3y9R1/!
I;u1mywd
String sURL; //File URL 2^3N[pM;
long nStartPos; //File Snippet Start Position xJ=@xfr$
long nEndPos; //File Snippet End Position XXwe/>J
int nThreadID; //Thread's ID mT:Z!sS
boolean bDownOver = false; //Downing is over "~:AsZ"7
boolean bStop = false; //Stop identical <4{Jm8zJ
FileAccessI fileAccessI = null; //File Access interface uC2-T5n'
O%hmGW4
Qf=+%-$Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException on0MhW
{ ^*-6PV#Z
this.sURL = sURL; 6!&DH#M
this.nStartPos = nStart; r:xbs0 7
this.nEndPos = nEnd; cJ^:b4j
nThreadID = id; PP1?UT=]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 * |dz.Tr
} >^odV ;^
=uG}pgh0
0UbY0sYo
public void run() p]lZ4#3
{ !=/wpsH
while(nStartPos < nEndPos && !bStop) ;kE|Vx
{ Y<vHL<G
cM|!jnKm
Tl/!Dn
try{ 8k.<xWDU
URL url = new URL(sURL); I=;.o>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8gIf
httpConnection.setRequestProperty("User-Agent","NetFox"); f$2DV:wuC
String sProperty = "bytes="+nStartPos+"-"; r9\7I7z
httpConnection.setRequestProperty("RANGE",sProperty); A ,$CYLj+
Utility.log(sProperty); 16cc9%
Qo%IZw$l
XCAy _fL<B
InputStream input = httpConnection.getInputStream(); Mtw7aK
//logResponseHead(httpConnection); k1h>8z.Tg
:U{$G( <
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byte[] b = new byte[1024]; p#QR^|7"
int nRead; #'qDNY@w}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7]J7'!Iz
{ `<oNEr+#
nStartPos += fileAccessI.write(b,0,nRead); CW+]Jv]"
//if(nThreadID == 1) (H[.\O-`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K5"8zF)*
} p)k5Uh"
v9_7OMl/x
o1k X`Eu
Utility.log("Thread " + nThreadID + " is over!"); hKjG/g:#G
bDownOver = true; q4xP<b^
//nPos = fileAccessI.write (b,0,nRead); l.iT+T
} Md5|j0#p
catch(Exception e){e.printStackTrace ();} Quts~Q
} pRez${f.(s
} .@`5>_
<Na .6P
Tu[I84
//打印回应的头信息 C" 2K U*
public void logResponseHead(HttpURLConnection con) g^mnYg5
{ <0h,{28
for(int i=1;;i++) {^jRV@
{ FpYeuH%
String header=con.getHeaderFieldKey(i); JjC& io
if(header!=null) J=`2{ 'l
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Rk$
Utility.log(header+" : "+con.getHeaderField(header)); CTP!{<ii
else tbm/gOBw
break; YLU.]UC
} *~%QXNn`
} :|z.F+-/
=cwdl7N&I
~:xR0dqx
public void splitterStop() `=.A])>
{ k>V~iA
bStop = true; 86f8b{_e"
} pH/_C0e`7
VEGp!~D
W2T-TI,>PC
} $ vt6~nfI
Sa 8T'%W
K2@],E?e%|
/* C(J+tbk
**FileAccess.java Evy_I+l
*//文件访问(定位，写) 'u84d=*l
package NetFox; 2,^U8/
import java.io.*; >V$ S\"
}9*NEU)o
(/^dyG|X'
public class FileAccessI implements Serializable{ 3;<Vv*a"Dm
I*`;1+`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %c-T Gr,
RandomAccessFile oSavedFile; `#c36
long nPos; t^|GcU]
.:(T}\]R
r=4vN=:
public FileAccessI() throws IOException *!c&[- g
{ ,w|Or}h]7
this("",0); x4Wu`-4^
} @;b @O _
9lR-
A2p]BW&
public FileAccessI(String sName,long nPos) throws IOException ?C`&*+
{ E06)&tF
oSavedFile = new RandomAccessFile(sName,"rw"); -A(]U"@n
this.nPos = nPos; ('oA{,#L
oSavedFile.seek(nPos); 4DV@-
} GWCU9n
?d5_{*]+v
8\Uy
public synchronized int write(byte[] b,int nStart,int nLen) gaC[%M
{ .qfU^AHA
int n = -1; Zk<Y+!
try{ 8k9q@FSln
oSavedFile.write(b,nStart,nLen); k*e$_
n = nLen; ]uZaj?%J<
} Dk#4^`qp1
catch(IOException e) pdq5EUdS
{ SpA-E/el
e.printStackTrace (); *OU&`\bmE
} fI"OzIJV
VxqoE]Dh
+&*Ybbhb
return n; D^<5gRK?
} I/k/5
|h%0)_
myqQqVW
} v:zKn[;o
mBON>Z[4.
^"GDaMF
/* ~@%#eg
**SiteInfoBean.java 6vr8rJ-
*/ nPg,(8Tt
package NetFox; YtFH@M
()ZP=\L
K0^Tg+U($p
public class SiteInfoBean { ?!;i/h*{
/?B%,$~
[t+qYe8
private String sSiteURL; //Site's URL P,*yuF|bk
private String sFilePath; //Saved File's Path 4#&w-W
private String sFileName; //Saved File's Name N D1'XCN
private int nSplitter; //Count of Splited Downloading File z:W|GDD1
5]F4.sa
HzZ.q2Zz%
public SiteInfoBean() kB]?95>Wx
{//nSplitter的缺省值为5 `^'0__<M
//default value of nSplitter is 5 3!Cab/T
this("","","",5); ot; ]?M
} SS7C|*-Zd
$m[*)0/
UYkuz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U`kO<ztk
{ gI{56Z
sSiteURL= sURL; Ur,{ZGm
sFilePath = sPath; "VI2--%v3
sFileName = sName; p.RSH$]
this.nSplitter = nSpiltter; aSH =|Jnc
@tVl8]y
+x)x&;B)/
} h{.x:pPXy
Hq0O!Zv
<ql:n
public String getSSiteURL() UdK+,k~m/
{ U!i@XA%P
return sSiteURL; $&KiN82,
} M <ccfU!
o!sHK9hvJ)
F,h}HlU
public void setSSiteURL(String value) 2UrE>_
{ XT{o ]S~nq
sSiteURL = value; 41#YtZ
} ?a{>QyL
=g<Y[Fi2
%+ur41HM
public String getSFilePath() f@H>by N
{ ^)S<Ha
return sFilePath; @i=_y+|d_
} uE^5o\To
oRQ(l I>
m:5x"o7)ln
public void setSFilePath(String value) vg-'MG
{ _GsHT\
sFilePath = value; tW=oAy
} t&nK5p95(
b0h>q$b
F:'>zB]-}
public String getSFileName() R:Tv'I1-L
{ R0bWI`$Z
return sFileName; ^9`~-w
} -MuKeCgi
~5 e 1&
q|S,^0cU
public void setSFileName(String value) f1X]zk(=W
{ 2PQY+[jx
sFileName = value; =e|
} %40+si3c
(&xIBF_6
tN-B`d1
public int getNSplitter() 0s%]%2ON
{ &U{"dJr
return nSplitter; 'aJm4W&j
} wY_! s Qo
}080=E
*(j-jbA
public void setNSplitter(int nCount) uV\~2#o$_
{ f\c%G=y
nSplitter = nCount; b_GAK
} '[Z.\
} Rq,Fp/
dZ"d`M>o6
DP=\FG"}x
/* $*vj7V_
**Utility.java *vP:+]
*/ 0&2eiMKG?n
package NetFox; Q)ZbnR2Z8
w02t9vz
_0!<iN L
public class Utility { [J+]1hCZ|
"Tc[1{eI
#b+>O+vx8
public Utility() &d i=alvv1
{ g0Jy:`M
z:p9&mi
U?(+ {4l
} ^|lG9z%Foy
B+2Jea,N
//线程睡眠 .MI 5?]_
public static void sleep(int nSecond) D}L4uz?
{ nCPIpw,]M
try{ 0;:AT|U/d
Thread.sleep(nSecond); pb}4{]sI
} &1M#;rE;D#
catch(Exception e) }W$}blbp
{ xT;j_'9U;
e.printStackTrace (); .R{+Pz D
} Aj "SSX!L
} .q_SA-!w>
HFTDea+#
//日志 axLO: Q,
public static void log(String sMsg) C5&+1VrP
{ _Rey~]iJJ8
System.err.println(sMsg); +8|r_z\A5a
} Wm>AR? b
*[0)]|r
hnnPi
public static void log(int sMsg) Y"'k $jS-
{ VDC"tSQ
System.err.println(sMsg); {6brVN.V
} 5HMDug;
} jW0aIS2O
YV"LM6`
z+F:_
/* O:Ob{k
**TestMethod.java w"?E=RS
*/ l527>7 eT
package NetFox; iYl$25k/1
f f_| 3G
+d/^0^(D\5
public class TestMethod { kJ:zMVN
l$eKV(CZ4
77o&$l,A|
public TestMethod() ?8aPd"x
{ ///xx/weblogic60b2_win.exe jG~UyzWH;
try{ V'XvwO@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J&jig?t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aFVd}RO0
SiteFileFetch fileFetch = new SiteFileFetch(bean); >? ({
fileFetch.start(); W.VyH|?
} 2Ik@L,
catch(Exception e){e.printStackTrace ();} X^ZUm
ffE&=eh)
uq_h8JH$
} |4u?Q+k%%
8@'Q=".J
*'hvYl/?>
public static void main(String[] args) @iD5X.c
{ Rhil]|a/
new TestMethod(); NJTC+`Hm
} N~@VZbS(6
} fE&wtw{gi
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