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)); XPqGv=CN
} du$M
for(int i=0;i<nEndPos.length-1;i++) 97\K]Tr
{ uA[ :
nEndPos = nStartPos[i+1]; YW6a?f^!
} s|A[HQUtJ
nEndPos[nEndPos.length-1] = nFileLength; , +J)`+pJx
} %q3`k#?<
} b way+lh
dWiNe!oY2
poW%Fzj
//启动子线程 ]r0j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <(@S;?ZEW
for(int i=0;i<nStartPos.length;i++) Jh=.}FXnjL
{ #J3o~,t<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HM0&%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), og35Vs0
nStartPos,nEndPos,i); 7r'_p$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ul/m]b6-
fileSplitterFetch.start(); {+_p?8X
} CF','gPnc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $Z]@N nA9N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "Zhh>cz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", PkyX,mr#1
nEndPos = " + nFileLength); dR.?Kv(,E
// fileSplitterFetch[nPos.length-1].start(); i"iy 0?
"1^tVw|
Hy\q{
//等待子线程结束 As>Og
//int count = 0; Uv>e :U7;
//是否结束while循环 0(Y,Q(JTo&
boolean breakWhile = false; *j]Bo,AC
+`gU{e,p
ysK J=
while(!bStop) TA/hj>rV
{ 4(P<'FK $
write_nPos(); $dKfUlO
Utility.sleep(500); @fmp2!?6
breakWhile = true; fi>.X99(G
mMllen
OET/4(C
for(int i=0;i<nStartPos.length;i++) 9-{+U,3)
{ `lOW7Z}
if(!fileSplitterFetch.bDownOver) 0_ST2I"Ln
{ }]dzY(
breakWhile = false; NY<qoV
break; s?m_zJh
} +U J~/XV
} o:ow"cOEf
if(breakWhile) !ck~4~J
break; 3]9wfT%d
$eT[`r
!:5'MI@
//count++; ~Azj Y8
//if(count>4) k=kkF"
// siteStop(); z.RM85?T
} q({-C
q{
H1q,w|O9j
System.err.println("文件下载结束！"); vv2[t
} @|"K"j#
catch(Exception e){e.printStackTrace ();} mDp8JNJNE
} :oW 16m1`
0Cf'\2
2i#Ekon
//获得文件长度 'j{o!T0
public long getFileSize() OY81|N j
{ 'lpCwH
int nFileLength = -1; 5c}loOq
try{ x\ #K2
URL url = new URL(siteInfoBean.getSSiteURL()); x|d?'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YW~ 9N
httpConnection.setRequestProperty("User-Agent","NetFox"); TYR \K
P"}"q ![
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int responseCode=httpConnection.getResponseCode(); z#`Qfvu6Hi
if(responseCode>=400) ~&<vAgy,
{ \Ezcr=0z{j
processErrorCode(responseCode); 7Q Ns q
return -2; //-2 represent access is error M6A0D+08
} /%jX=S.5h<
9dAtQwGR"6
=~W=}
String sHeader; M,kO7g
xj8z*fC;
j@+$lU*r
for(int i=1;;i++) @^ &p$:
{ sz/^Ie-~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); P'}B5I~
//Utility.log(in.readLine()); :t "_I
sHeader=httpConnection.getHeaderFieldKey(i); Qa:[iF
if(sHeader!=null) s3@mk\?qMe
{ t\YM Hq<Y
if(sHeader.equals("Content-Length")) b+arnKo1fk
{ P{n*X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gxUa-R
break; m`$Q/SyvG
} cvT@`1
} &\cS{35
else uF}B:53A
break; +%klS `_
} !J@!2S9
} ]=i('|YG
catch(IOException e){e.printStackTrace ();} .$y'>O*$G
catch(Exception e){e.printStackTrace ();} ,=G]tnsv^
\Z42EnJ
/|H9Gm
Utility.log(nFileLength); }><[6Uz%
L{r4hL [
{{M/=WqC
return nFileLength; xz.M'az\
} s>\^dtG7
3< 6h~ek)
.<fdX()e,
//保存下载信息（文件指针位置） .GNyADQp
private void write_nPos() W|zPV`
{ EN/t5d
try{ =6=:OId
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?Y8hy|`
output.writeInt(nStartPos.length); H%rNQxA2 +
for(int i=0;i<nStartPos.length;i++) 7j=KiiI
{ } d8\ Jg
// output.writeLong(nPos); cjg~?R
output.writeLong(fileSplitterFetch.nStartPos); xHaz*w1|
output.writeLong(fileSplitterFetch.nEndPos); X2%(=B
} oUN\tOiS+
output.close(); Lr8|S
} QE)zH)(
catch(IOException e){e.printStackTrace ();} h.ftl2>
catch(Exception e){e.printStackTrace ();} `\;Z&jlpT
} Tl[*(|/C
5}]+|d;
$Q'z9ghEg
//读取保存的下载信息（文件指针位置） SVn@q|N
private void read_nPos() mF+8Q
{ .{`C>/"}
try{ r[;d.3jtP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]a~sJz!
int nCount = input.readInt(); zG9D Ph
nStartPos = new long[nCount]; Y[}A4`
nEndPos = new long[nCount]; aD'Ax\-
for(int i=0;i<nStartPos.length;i++) u'_}4qhCC;
{ [v*q%Mi_
nStartPos = input.readLong(); 9"gu>
nEndPos = input.readLong(); "gm5DE
} q6nRk~
input.close(); (6a<{
} W,CAg7:*
catch(IOException e){e.printStackTrace ();} i}v.x
catch(Exception e){e.printStackTrace ();} 2; ,8 u
} .n YlYY'
AgSAjBP
s>L.V2!$0
private void processErrorCode(int nErrorCode) Ny$3$5/
{ #Mk:4
System.err.println("Error Code : " + nErrorCode); g.hYhg'KUh
} u)o-H!a
Cfd* Q
~ *"iLf@,
//停止文件下载 `<>QKpAn
public void siteStop() |D/a}Av>B
{ ~:f..|JM
bStop = true; Lkx~>U
for(int i=0;i<nStartPos.length;i++) @d 7V@F0d
fileSplitterFetch.splitterStop(); u?dPCgs;h
?jlz:Z4
>jIn&s!}
} X"_ ^^d-
} <Ohi+a%6
//负责部分文件的抓取 Z10}xqi!X
**FileSplitterFetch.java l}VE8-XB
*/ m<>BxX
package NetFox; _Q I!UQdW
YT(Eh3ID
[ fzYC'A=
import java.io.*; Q#SQ@oUzD
import java.net.*; JOt(r}gU
Q#H"Se
;2&"
public class FileSplitterFetch extends Thread { p2t04p!
*OFG3uM
msfE;
String sURL; //File URL N=2T~M 1
long nStartPos; //File Snippet Start Position s[0`
long nEndPos; //File Snippet End Position eeCG#NFY5
int nThreadID; //Thread's ID vZTXvdF
boolean bDownOver = false; //Downing is over *{fs{gFw9
boolean bStop = false; //Stop identical h`1<+1J9
FileAccessI fileAccessI = null; //File Access interface ' :B;!3a0d
jUA~}DVD
/ugyUpyg
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0,ryy,2
{ !KK`+ 9/
this.sURL = sURL; ?=&S?p)-<
this.nStartPos = nStart; &U]/SFY
this.nEndPos = nEnd; 0@cIj ]
nThreadID = id; b}0h()v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 eZT8gKbjJ)
} MukJ^h*V
? F #&F
<.4(#Ebd
public void run() N?vb^?
{ ,k4pW&A
while(nStartPos < nEndPos && !bStop) %mT/y%&:
{ n Ab~
(=7"zECq#
nI6ompTX
try{ 8Zsaq1S
URL url = new URL(sURL); @y;VV*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \~,\|
httpConnection.setRequestProperty("User-Agent","NetFox"); VM\R-[
String sProperty = "bytes="+nStartPos+"-"; aH_c84DS
httpConnection.setRequestProperty("RANGE",sProperty); x0Loid\f
Utility.log(sProperty); a&8K5Z%0
nahq O|~
WC~;t4
InputStream input = httpConnection.getInputStream(); d0I s|Gs
//logResponseHead(httpConnection); Ex p?x
15j5F5P
jC>ZMy8U)4
byte[] b = new byte[1024]; N { oVz],
int nRead; %(eQ1ir+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) KUZi3\p9W>
{ ?tjEXg>ny
nStartPos += fileAccessI.write(b,0,nRead); S#C-j D
//if(nThreadID == 1) (t@)`N{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V[/9?5pM
} [y`Gp#
q][kD2
M,H8ZO:R
Utility.log("Thread " + nThreadID + " is over!"); >]~581fYf
bDownOver = true; !FP ]
//nPos = fileAccessI.write (b,0,nRead); l.pxDMY
} ,g7O
catch(Exception e){e.printStackTrace ();} EWDsBNZaI
} WS n>P7sY
} |(%<FY$
g.9C>>tj
5\quh2Q_
//打印回应的头信息 HU?1>}4L
public void logResponseHead(HttpURLConnection con) PxrT@.T$
{ RG45S0Ygj
for(int i=1;;i++) SnFyK5
{ L%v@|COQ3
String header=con.getHeaderFieldKey(i); TzaeE
if(header!=null) <<d#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]"V_`i7Z
Utility.log(header+" : "+con.getHeaderField(header)); ?pEPwc
else R&W%E%uj
break; SzpUCr"
} 3\m!
} jq)Bj#'7
>WLX5i&
fphCQO^#vW
public void splitterStop() :} =lE"2
{ G;cC!x<
bStop = true; N:U}b1$L6
} x*z&#[(0g!
72~L ?
_(g0$vRP~
} ,(q] $eOZ
yC$m(Y12FN
^=^\=9" b
/* `oNJ=,p
**FileAccess.java 3 orZBT
*//文件访问(定位，写) QBGm)h?=
package NetFox; 6HBDs:
import java.io.*; u3qxG3
}kQ{T:q4
U)f('zD
public class FileAccessI implements Serializable{ o#6QwbU25
tgG 8pL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,u>LAo0
RandomAccessFile oSavedFile; J/P[9m30[
long nPos; roc DO8f
Y _`JS;
KE"6I
public FileAccessI() throws IOException :z P:4NW
{ swZi O_85
this("",0); `w#VYs|k
} V~*>/2+
L}{3_/t
&c!6e<o[p
public FileAccessI(String sName,long nPos) throws IOException RK-bsf
{ F8<G9#%s\
oSavedFile = new RandomAccessFile(sName,"rw"); 0IqGy}+VU
this.nPos = nPos; az![u)
oSavedFile.seek(nPos); k^|z.$+
} D"aK;_W@h
'8zd]U
'gor*-o:wu
public synchronized int write(byte[] b,int nStart,int nLen) zZPWE"u}
{ :(ql=+vDb4
int n = -1; PEEaNOk 1b
try{ MzUKp"
oSavedFile.write(b,nStart,nLen); ;UgwV/d
n = nLen; 9;%$
} 2?%4|@*H?
catch(IOException e) ?bM%#x{e
{ I~F&@
e.printStackTrace (); X@[5nyILf
} e0y.J
ij:a+T
{sB-"NR`K
return n; 7.VP7;jys
} $!. [R}
|sr\SCx
RQWUO^&e^
} {M:/HQo
]vB^%
\?v&JmEU
/* 5P<1I7d
**SiteInfoBean.java Pq<43:*?
*/ p_BG#dRM
package NetFox; En7+fQ
`f}ZAX
::02?
public class SiteInfoBean { s[{8:Px
}Y.@:v j
=.S2gO >
private String sSiteURL; //Site's URL b?0WA.[{
private String sFilePath; //Saved File's Path Bi fI.2|
private String sFileName; //Saved File's Name +e>G V61
private int nSplitter; //Count of Splited Downloading File exSwx-zxI
l]DRJ
!V#*(_+n
public SiteInfoBean() pvt/{
{//nSplitter的缺省值为5 IuPDr %
//default value of nSplitter is 5 P[H`]q|
this("","","",5); xF) .S@
} :FSg%IUX
PNLlJlYlP
EX<1hAw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :/? Op
{ G2[2y-Rv
sSiteURL= sURL; HSG9|}$
sFilePath = sPath; ]lJ#|zd8o
sFileName = sName; X+emJ&Z$@
this.nSplitter = nSpiltter; 3H"F~_H
#9"lL1
z}5'TV=^
} 25, [<Ao
$a\X(okx
0~<t :q!
public String getSSiteURL() h*P0;V`UX
{ *Z"Kvj;>u
return sSiteURL; uTbMp~cYB
} cEJ_z(\=hr
E.VEW;=
N9)ERW2`*
public void setSSiteURL(String value) bg4VHT7?>)
{ qj*BV
sSiteURL = value; 5hCfi
} ?K}KSJ6_
wL0"1Ya
. 55aY~We
public String getSFilePath() q|D*H9[ke
{ H<b4B$/
return sFilePath; gAi}"};
} yNx"Ey dk`
[iSLn3XXRX
tK <)A)
public void setSFilePath(String value) A,ao2)
{ J_|>rfW
sFilePath = value; `+r5I5
} BT{({3
R?%|RCht1
C$B?|oUJc
public String getSFileName() 483vFLnF
{ e''Wm.>g(+
return sFileName; JeCEj=_Z
} wA)R7%&
7 ~ Bo*UM
}@A~a`9g
public void setSFileName(String value) R?\8SdJ
{ 3?/}
sFileName = value; *JOv
} (C QgT3V
}mJ)gK5b 6
veE8 N~0N.
public int getNSplitter() K<_H`k*x
{ +V\NMW4d
return nSplitter; #wm)e)2@
} `0 F"zu
o_$r*Z|HG
G6Fg<g9:
public void setNSplitter(int nCount) Ri-wbYFaP
{ Wj*6}N/
nSplitter = nCount; C"mb-n7s
} ;NPb
} CC87<>V
V[#lFl).
@',;/j80
/* P?uKDON
**Utility.java mg;AcAS.o,
*/ ;~q)^.K3
package NetFox; Tp6ysjao
!c`1~a!
^ pR&
public class Utility { vA{[F7
&]c9}Ic
\%^3Izsc
public Utility() ! O>mu6:Rf
{ Ek.j@79
~gDtj&F
)T+htD)
} g?+P&FL#I
Kj>_XaFCg!
//线程睡眠 gy[uqm_ T
public static void sleep(int nSecond) C|JWom\J
{ 8+W^t I
try{ ZqGq%8\.s
Thread.sleep(nSecond); 1f:k:Y9i
} [)=FZF6kG
catch(Exception e) 8YJ({ Ou_
{ M;bQid@BG
e.printStackTrace (); ;g*6NzdA
} ,5*4%*n\
} 3IxT2@H)
wDG4rN9x
//日志 WQ]pg "
public static void log(String sMsg) mB~&nDU
{ .PxM #;i2
System.err.println(sMsg); h^)2:0#{I
} hU{%x#8}lK
s5dh]vNN
5*r6#[S\
public static void log(int sMsg) /_|1,x-Kx
{ wtKh8^:YD
System.err.println(sMsg); Kna'5L5"
} 90!Ib~7zH
} 6M9rC[h\
{1+H\(v
B+LNDnjO]
/* S-LZ(o{ZL
**TestMethod.java 3gI[]4lRH
*/ D _bkUR1
package NetFox; \Ul.K!b7
O{B e )E~
-wfRR>)d
public class TestMethod { g<rKV+$6
:<t{ =0G
CmJ?_>
public TestMethod() ,na=~.0R:
{ ///xx/weblogic60b2_win.exe V@f6Lj
try{ EOBs}M;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m,@1LwBH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d@D;'2}Yc
SiteFileFetch fileFetch = new SiteFileFetch(bean); aucZJjH
fileFetch.start(); %CxEZPe$
} Pn+IJ=0Y
catch(Exception e){e.printStackTrace ();} ;Y@!:p-H
` Y{>2UFX
yNrinYw
} $c@w$2
|-(IJG#)
N;Z`%&
public static void main(String[] args) q:Y6fbt<7
{ <2)s<S.;
new TestMethod(); KMK&[E#r
} "K|)<6J
} 6%gB E
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