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)); tHhA_
} ,q yp2Y7
for(int i=0;i<nEndPos.length-1;i++) !]tZE%?
{ LbGyD;#_
nEndPos = nStartPos[i+1]; c&Pgz~iP
} MB,;HeP!
nEndPos[nEndPos.length-1] = nFileLength; _v2K1 1
} ;c5Q"
} "{0 o"k
p[*NekE6-
O!!Ne'I
//启动子线程 sjLI^#a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Vi~9[&.E\!
for(int i=0;i<nStartPos.length;i++) em@\S
{ kcd~`+C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pZRKM<k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9}`A_KzFx
nStartPos,nEndPos,i); p]*BeiT#n%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i%7b)t[y
fileSplitterFetch.start(); ~ #Gu:
} ;C8'7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YadY?o./
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A&i
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hB#z8D
nEndPos = " + nFileLength); i[b?W$]7
// fileSplitterFetch[nPos.length-1].start(); cGw*edgp6
v%|()Z0
[@@Ovv
//等待子线程结束 3IqYpK(s
//int count = 0; n237%LH[
//是否结束while循环 lgC|3]
boolean breakWhile = false; J7R+|GTcx
*pN,@ZV$
RltG/ZI
while(!bStop) 'J^E|1P
{ C[$uf
write_nPos(); )1H$5h
Utility.sleep(500); N{@kgc
breakWhile = true; ^Bihm] Aq
`F:PWG`
8S1%;@c
for(int i=0;i<nStartPos.length;i++) %gB 0\C
{ |[x) %5F
if(!fileSplitterFetch.bDownOver) W! FmC$Kc
{ Z7&Bn
breakWhile = false; iYj+NL
break; XfFZ;ul
} `, ?T;JRc
} 2U6j?MyH2
if(breakWhile) b'Gn)1NE
break; @>'.F<:P<
K;2tY+I
4*9y4"
//count++; rm*Jo|eH`
//if(count>4) G0Wzx)3]
// siteStop(); N1ZHaZ
} Fkas*79
$smzP.V
&$fe%1#
System.err.println("文件下载结束！"); F"9f6<ge
} )J+vmY~&
catch(Exception e){e.printStackTrace ();} 7\aLK#
} 5gWn{[[e)y
=:(8F*Q
8Z>ZjNG
//获得文件长度 uY;-x~Z
public long getFileSize() 7SE=otZ>
{ 7>EjP&l
int nFileLength = -1; k*\=IacX0
try{ LQSno)OZ
URL url = new URL(siteInfoBean.getSSiteURL()); &*Eyw s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8cy#[{u`;
httpConnection.setRequestProperty("User-Agent","NetFox"); 95giqQ(N
-\@&^e
t#mW`rGE_
int responseCode=httpConnection.getResponseCode(); hqVx%4s*J
if(responseCode>=400) &#Sg1$/+
{ .L%_#A
processErrorCode(responseCode); ni gp83:
return -2; //-2 represent access is error QnikgV
} vyT$IdV2
CqDMq!
HPs$R[
String sHeader; 5:SfPAx
w}pFa76rm
^I9x@t
for(int i=1;;i++) P-ma~g>I
{ :NHh`@0F
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '3eP<earRP
//Utility.log(in.readLine()); /EhojODMF
sHeader=httpConnection.getHeaderFieldKey(i); Kx6_Vp
if(sHeader!=null) ,%X~/V
{ |{HtY
if(sHeader.equals("Content-Length")) )RlaVAtM
{ C\UD0r'p?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); elXY*nt8h
break; 0mL#8\'"
} EKf"e*|(L
} !G3O!]
else 72} MspzUt
break; [Z0&`qz
} yB(^t`)}N
} ]c8lZO>
catch(IOException e){e.printStackTrace ();} 0Z#&!xTb
catch(Exception e){e.printStackTrace ();} 3/o-\wWO
sj003jeko
rixNz@p'%
Utility.log(nFileLength); ~q#UH'=%
6gfv7V2H
Zr'VA,v
return nFileLength; ihKnZcI$i
} y1^<!I
RH^8"%\
mKynp
//保存下载信息（文件指针位置） +](^gaDw<L
private void write_nPos() IZeWswz
{ GEy^*, d
try{ Z2`(UbG}
output = new DataOutputStream(new FileOutputStream(tmpFile)); o <8L,u(U
output.writeInt(nStartPos.length); 1p>5ZkHb
for(int i=0;i<nStartPos.length;i++) I(ds]E ;_E
{ HgE^#qD?
// output.writeLong(nPos); 3t[2Bd
output.writeLong(fileSplitterFetch.nStartPos); d@pD5n=m;
output.writeLong(fileSplitterFetch.nEndPos); @v_ )(
} "#d}S)GlXM
output.close(); Lm"a3Nb
} HS]|s':
catch(IOException e){e.printStackTrace ();} tlu-zUsi
catch(Exception e){e.printStackTrace ();} &H;0N"Fn
} 828E^Q"<
$/nU0W
=:mD)oX*
//读取保存的下载信息（文件指针位置） z#GZvB/z)
private void read_nPos() -?'r_t
{ &(-+?*A`E
try{ dGf{d7D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wz31e!/
int nCount = input.readInt(); jTaEaX8+
nStartPos = new long[nCount]; v/\l
nEndPos = new long[nCount]; 0Pu$1Fp
for(int i=0;i<nStartPos.length;i++) ] 7_ f'M1F
{ =K~<& l8
nStartPos = input.readLong(); 0sto9n3
nEndPos = input.readLong(); gI6./;;x
} w_q{C>-cR
input.close(); QNJ )HNLp
} fmY=SqQG-
catch(IOException e){e.printStackTrace ();} \$}^u5Y
catch(Exception e){e.printStackTrace ();} i&$L$zf,
} W'eF | hu
kUUeyq
yNi/JM
private void processErrorCode(int nErrorCode) eaCv8zdX
{ AK%`EsI^
System.err.println("Error Code : " + nErrorCode); TZTi:\nS
} 4,!#E0
DXl3
0#0[E,
//停止文件下载 [U.3rcT"N
public void siteStop() XT> u/Z)
{ URdCV{@42
bStop = true; s'qd%JxD
for(int i=0;i<nStartPos.length;i++) EE(1;]d-
fileSplitterFetch.splitterStop(); |RS9N_eRt
~CCRs7V/L
{DJ!T
} oP;"`^_
} <]xGd!x$
//负责部分文件的抓取 luRtuXn[8
**FileSplitterFetch.java pyYm<dn
*/ 1`J-|eH=Q
package NetFox; ;NQ9A &$)
dU<\FW_
I},.U&r
import java.io.*; "7}bU_":s
import java.net.*; }vzP\
L"{qF<@V7&
q{~59{Fha
public class FileSplitterFetch extends Thread { &u&+:m
KK$t3e)
w#mnab@
String sURL; //File URL ;]!QLO.bs^
long nStartPos; //File Snippet Start Position Ey96XJV
long nEndPos; //File Snippet End Position `u6CuH5
int nThreadID; //Thread's ID 4o?_G[
boolean bDownOver = false; //Downing is over /iURP-rl
boolean bStop = false; //Stop identical 36"-cGNr{
FileAccessI fileAccessI = null; //File Access interface l7#5.%A
@ =g Px
U[7 &
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Sv3O${B|
{ /2z, ?,jL
this.sURL = sURL; OBY^J1St
this.nStartPos = nStart; )+ifVv50
this.nEndPos = nEnd; j'r"_*%
nThreadID = id; 4P(muOS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X.}i9a 6
} /c2| *"@X
JC6?*R
3{c6)vR2
public void run() =D-u".{
{ =T"R_3[NC
while(nStartPos < nEndPos && !bStop) cG!\P:re
{ R|&jvG=|
Nini8@d
rSu+zS7`X
try{ M;2@<,rM
URL url = new URL(sURL); |)~t^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eka<mq|W
httpConnection.setRequestProperty("User-Agent","NetFox"); -)N,HAM>
String sProperty = "bytes="+nStartPos+"-"; FK;3atrz
httpConnection.setRequestProperty("RANGE",sProperty); ,GOH8h
Utility.log(sProperty); EPeKg{w
|ppG*ee
"06t"u<%
InputStream input = httpConnection.getInputStream(); I;xSd.-
//logResponseHead(httpConnection); {:=sCY!
[}>!$::Y
\dAs<${(
byte[] b = new byte[1024]; suOWmqLs
int nRead; )LC"rSNx%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /=5:@
{ 'Fq+\J#%
nStartPos += fileAccessI.write(b,0,nRead); s#Ayl]8r
//if(nThreadID == 1) U80h0t%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KC+jHk
} L2\<iJA}c
'[WVP=M<XV
XrUc`
Utility.log("Thread " + nThreadID + " is over!"); W6c]a/
bDownOver = true; ]`eP"U{
//nPos = fileAccessI.write (b,0,nRead); n2A ; `=
} xeNj@\jdC5
catch(Exception e){e.printStackTrace ();} _DouVv>
} ;cEoc(<?
} gpw,bV
}3O 0nab
c7~'GXxQ2
//打印回应的头信息 -I?8\
public void logResponseHead(HttpURLConnection con) *fCmZ$U:{
{ [$X^r<|P@
for(int i=1;;i++) 4`e[gvh
{ xyD2<?dGUb
String header=con.getHeaderFieldKey(i); vf5q8/a
if(header!=null) a[_IG-l|i4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OKPNsN
Utility.log(header+" : "+con.getHeaderField(header)); R53^3"q~
else Xp+lpVcJ
break; r;^%D(
} j7BLMTF3v
} VUi> ]v/e
)+Y"4?z~
=PF2p'.o
public void splitterStop() D7r&z?
{ ZEK,Z['
bStop = true; OO2uE ;( 3
} S]&:R)#@
c)3.AgT
{'p < o$(S
} n:[@#xs-
@>,GCuPrm
VOJ/I Dl 4
/* #;[0:jU0
**FileAccess.java h/Yxm2
*//文件访问(定位，写) kRjNz~g
package NetFox; uBK0+FLL@
import java.io.*; a&2UDl%K
[vY#9W"!
&]h`kvtBC
public class FileAccessI implements Serializable{ uPq@6,+
to'CuPkT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RFLfvD<
RandomAccessFile oSavedFile; IH&0>a
long nPos; aGd wuD
j1;<3)%0
f^-ot@w
public FileAccessI() throws IOException ;F|#m,2Q-
{ riL|B3
this("",0); dF[|9%)
} hF{gN3v5
^RJ@9`P&t
* RyU*au
public FileAccessI(String sName,long nPos) throws IOException tI@aRF=p]2
{ XzPOqZ`Nv
oSavedFile = new RandomAccessFile(sName,"rw"); F$-fj "jC
this.nPos = nPos; t.+)g-X
oSavedFile.seek(nPos); #mU<]O
} qm"SN<2S*
;mYZ@g%e
0 *;i]owV
public synchronized int write(byte[] b,int nStart,int nLen) wz)s
{ _Vl~'+e
int n = -1; -u(,*9]cJ*
try{ Lk!m1J5
oSavedFile.write(b,nStart,nLen); \FUMfo^
n = nLen; 6J\ 2=c`
} }L(ZLt8Q
catch(IOException e) -K lR":
{ suzK)rJ9i
e.printStackTrace (); kia[d984w
} rFGPS%STS
k33\;9@k
Ph%{h"
return n; SXP(C^?C
} sE'c$H
b*(K;`9)B
8Ji`wnkXe
} c9G%;U)
(5@H<c^6
X0iy
/* !uoT8BBAk
**SiteInfoBean.java oN[}i6^,e
*/ O\ _ro.
package NetFox; >|c?ZqW
:._Igjj$=
I-/>M/66
public class SiteInfoBean { 4Z>gK(
Gh/nNwyu<
#6vf:94
private String sSiteURL; //Site's URL %g:'6%26
private String sFilePath; //Saved File's Path 78{9@\e"0
private String sFileName; //Saved File's Name 4BUG\~eI3
private int nSplitter; //Count of Splited Downloading File ?Wz2J3A.2t
2GORGS%
(c)=Do=
public SiteInfoBean() 8HFCmY#
{//nSplitter的缺省值为5 :'B(DzUR
//default value of nSplitter is 5 SzIzQR93&
this("","","",5); :Fm*WqZu
} >SLQW
_}Qtx/Cg
0VcHz$ 6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "b~C/-W I
{ umWs8-'Uw
sSiteURL= sURL; ">.tPn
sFilePath = sPath; mW4Cc1*
sFileName = sName; dVYY:1PS
this.nSplitter = nSpiltter; WKiP0~
QmjE\TcK/
;&n iZKoe
} y%ij)vQY
jhf# gdz%
HA8A}d~
public String getSSiteURL() (BPO*'
{ ~CT]&({
return sSiteURL; >G8I X^*sG
} &:5*^1oP
>t)Pcf|s
C 2nmSXV
public void setSSiteURL(String value) {j9TzR
{ sWo}Xq#
sSiteURL = value; <#ON
} ;YR/7
[:.wCG5
_\KFMe=PV
public String getSFilePath() Dc@O Mr
{ 5"@>>"3U
return sFilePath; {Y@shf;
} ~9 .=t'
cFw-JM<
SFRP ?s
public void setSFilePath(String value) ,\J 8(,%L
{ <wk
sFilePath = value; !DzeJWM|
} #<< el;n
BW7AjtxQ&
{iX#
public String getSFileName() ". tW5O>
{ |dLr #+'az
return sFileName; wYf\!]}'
} . 2$J-<O
5PO_qr=Hx
JyZuj>` 6
public void setSFileName(String value) tO{{ci$-T
{ !h4T3sO
sFileName = value; :c~SH/qS
} TL2E|@k1]
'";#v.!
U@NCN2I
public int getNSplitter() n!4\w>h
{ mFF4qbe
return nSplitter; >2znn&gZ
} A|8"}Hm
~jL%l
0WC\uxT7
public void setNSplitter(int nCount) ekvs3a^
{ B^/MwD>%
nSplitter = nCount; #zTy7ZS,0
} a*y9@RC}
} a~7D4G
`s)4F~aVo
V?j,$LixY
/* 6 X~><r
**Utility.java ).;{'8Q
*/ i"}z9Ae~.
package NetFox; n7fhc*}:`
!CUl1L1DSi
Jz`jN~
public class Utility { BDI@h%tJb:
:oZ<[#p"*
6p4BsWPx
public Utility() 2.aCo, Kb;
{ xT"V9t[f
QCW4gIp
9>&zOITTaL
} bI &<L O
@4*:qj?
//线程睡眠 U`qkeNd
public static void sleep(int nSecond) iSCkV2
{ `-uE(qp
try{ ^wolY0p
Thread.sleep(nSecond); S/XU4i:aV
} aDdGhB
catch(Exception e) zG#5lzIu,
{ F,Q;sq
e.printStackTrace (); 3P6O]x<-?
} %3a-@!|1<
} 8TFQ%jv
wnokP
//日志 Ei_~K';
public static void log(String sMsg) cF8 2wg
{ _/LGGt4&%
System.err.println(sMsg); W^[FWFUTY
} Y/5M)AyJt
6Cj7 =|L7
2'?'dfj
public static void log(int sMsg) :cC$1zv@
{ Q]K` p(
System.err.println(sMsg); ,,{;G'R|
} ~A=zjkm
} W<)P@_+-
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}*6BaB
/* =IC.FT}
**TestMethod.java mITB\,,G
*/ op}!1y$9P
package NetFox; S?0o[7(x*
45c?0tj
Y6v{eWtSn
public class TestMethod { 3^UdB9j;
5*$yY-A
O=2|'L'h!
public TestMethod() I_<VGUk
{ ///xx/weblogic60b2_win.exe 6j(/uF4!#
try{ Mh7m2\fLbd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yiZtG#6K{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H.ZIRt!RB
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^&?,L@fW
fileFetch.start(); EH|+S
} <c}@lj-j
catch(Exception e){e.printStackTrace ();} 3s%?)z
N[/<xW~x?4
pt<zyH3Z
} &zJI~R
=K`.$R
\1<'XVS
public static void main(String[] args) L0wT:x*
{ ^o3,YH
new TestMethod(); eq6O6-
} 5%Qxx\q
} *2zp>(%
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