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)); rRxqV?>n!
} Lq:Z='Kc
for(int i=0;i<nEndPos.length-1;i++) ]`%cTdpLj
{ C 7v 8
nEndPos = nStartPos[i+1]; :7'anj
} \O[Cae:^?
nEndPos[nEndPos.length-1] = nFileLength; n,`&f~tap
} ` 6PdMvF
} w;XXjT
ffdyDUzQ
z' @F@k6
//启动子线程 ~e|~c<!z8@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |#k1a:
for(int i=0;i<nStartPos.length;i++) Hly$ Wm
{ Tw$lakw
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4q2aVm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V}&
nStartPos,nEndPos,i); <3'r&ks
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }JS?42CTaV
fileSplitterFetch.start(); xRb-m$B}L
} E=7~\7TE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J^U#dYd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *g7dB2{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >>p3#~/
nEndPos = " + nFileLength); tcfUhSz,I
// fileSplitterFetch[nPos.length-1].start(); Y>r9"X|&H
IYd)Vv3'j
fN@2 B
//等待子线程结束 ydw')Em
//int count = 0; AkGCIn3
//是否结束while循环 9k1n-po
boolean breakWhile = false; %A04'dj`zQ
.-{B
ACs?m\$Q
while(!bStop) dAR):ZKq?
{ tJc9R2
write_nPos(); 94Z~]C
Utility.sleep(500); m8.sHw
breakWhile = true; 99vm7"5hQ
=F6J%$
d+$a5 [^9
for(int i=0;i<nStartPos.length;i++) bX8Bn0#a+
{ +`zM^'^$
if(!fileSplitterFetch.bDownOver) Ie4}F|#=
{ &{99Owqg
breakWhile = false; U)2\=%8
break; M '[.ay
} ,u/GA<'#M
} lCDXFy(E
if(breakWhile) u9J;OsnHK
break; F4@``20|
WI' ;e4
Y6f0 ?lB
//count++; ):1NeJOFF
//if(count>4) K_(o D O
// siteStop(); sJ,:[
} .xS}/^8iD
r\Zz=~![<
;kY'DKL(
System.err.println("文件下载结束！"); !>+YEZ"
} b k 30d
catch(Exception e){e.printStackTrace ();} Z3)1!|#Q
} Zj%l (OVq
,*Jm\u
1 %K^(J;
//获得文件长度 j"hfsA<_I
public long getFileSize() !q mnMY$
{ t0(1qFi
int nFileLength = -1; 5^+>*z
try{ ;CD@RP{$n
URL url = new URL(siteInfoBean.getSSiteURL()); qdWsP9}q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1d,;e:=j
httpConnection.setRequestProperty("User-Agent","NetFox"); hT]\*},
X0O@,
YLk/16r
int responseCode=httpConnection.getResponseCode(); $ba3dqbCW
if(responseCode>=400) 1jO}{U
{ 6"b =aPTi
processErrorCode(responseCode); @Pb!:HeJE
return -2; //-2 represent access is error U:"E:Bxz;m
} 30bScW<08
:A.dlesv6
k%Jv%m}aB
String sHeader; Mt"j< ]EW
C;QIp6"1
0x*L"HD
for(int i=1;;i++) _gxI=EYi
{ F6`$5%$M;?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8K=sx@l
//Utility.log(in.readLine()); 1--_E,Su>
sHeader=httpConnection.getHeaderFieldKey(i); x8+W9i0[1
if(sHeader!=null) v@(Y:\>
{ ,onOwPz
if(sHeader.equals("Content-Length")) fL>>hBCqC
{ fO|oV0Rw
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8bd&XieE
break; $9)|cO
} 'tm%3` F
} WW\t<O;z
else S3l$\X;6X
break; :+: vBrJm
} eD2u!OKW!
} D-JG0.@
catch(IOException e){e.printStackTrace ();} Fg;V6s/>ts
catch(Exception e){e.printStackTrace ();} =8#$'1K,v
w,f1F;!q1
'[g@A>xDvW
Utility.log(nFileLength); RsU!mYs:H
qVjl8%)
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return nFileLength; d[eN#<
} &]~Vft l
qn=~4rg]R
I*hCIy#;
//保存下载信息（文件指针位置） +X#JCLD
private void write_nPos() Kw_> X&GcJ
{ $ReoIU^<
try{ tn>z%6;&Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); !(QDhnx}9c
output.writeInt(nStartPos.length); #[=%+*Q
for(int i=0;i<nStartPos.length;i++) D; i%J
{ T$)N2]FE
// output.writeLong(nPos); i^`]TOP
output.writeLong(fileSplitterFetch.nStartPos); ^FJ.C|l(
output.writeLong(fileSplitterFetch.nEndPos); y(!J8(yA
} `IN/1=]5
output.close(); AM?62
} `0'Bg2'
catch(IOException e){e.printStackTrace ();} 2vbm=~)$F
catch(Exception e){e.printStackTrace ();} 7S'3U}Y>VX
} cG{>[Lf
NFxs4:] RT
z86[_l:
//读取保存的下载信息（文件指针位置） :jo !Yi
private void read_nPos() 9OI&De5?=V
{ b8o}bm{s
try{ /1OzX'5f
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JzI/kH~
int nCount = input.readInt(); l.gt+e
nStartPos = new long[nCount]; c0}* $e
nEndPos = new long[nCount]; q3Tp/M.
for(int i=0;i<nStartPos.length;i++) I#?NxP\S
{ u^5X@.
nStartPos = input.readLong(); 98"/]ERJ
nEndPos = input.readLong(); iPoh2
} n^kszIu~
input.close(); N!RkV\:X
} U5_1-wV
catch(IOException e){e.printStackTrace ();} eksYIQZ]
catch(Exception e){e.printStackTrace ();} !LDuCz -
} tw{V7r~n
WJD1U?`
\r4QS
private void processErrorCode(int nErrorCode) {tqLH2cO
{ *}\}@0%
System.err.println("Error Code : " + nErrorCode); #*r u*
} [,_4#Zz
3JnBKh\n
Dj0`#~
//停止文件下载 %#g9d
public void siteStop() t>]wWYy
{ ~_|OGp_a
bStop = true; ~ 8hAmM
for(int i=0;i<nStartPos.length;i++) o'uv5asdb
fileSplitterFetch.splitterStop(); -^a?]`3_v
60*;a*cy
#A&(b}#:o
} Nw74T
} YSQB*FBz
//负责部分文件的抓取 tp4/c'w;)J
**FileSplitterFetch.java ~k}>CNTr
*/ |gl~wG1@
package NetFox; KaRdO
)+!~xL
/<J&ZoeJB
import java.io.*; qhNY<
import java.net.*; S4qj}`$ Yv
F%<hng%k
$]H^?
public class FileSplitterFetch extends Thread { Hjho!np
y}TiN!M
{i}z|'!
String sURL; //File URL kZ^}
long nStartPos; //File Snippet Start Position g8I=s7cnb
long nEndPos; //File Snippet End Position y:\ ^[y IQ
int nThreadID; //Thread's ID zQ[g*
boolean bDownOver = false; //Downing is over )qi/>GR,
boolean bStop = false; //Stop identical *&iSW~s
FileAccessI fileAccessI = null; //File Access interface [5KzawV
4s{_(gy
y]z^e\qc)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WGG Va
{ mn5"kYy?
this.sURL = sURL; M@LI(;
this.nStartPos = nStart; !kzC1U
this.nEndPos = nEnd; 86.LkwlqoH
nThreadID = id; xUp[)B6?:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D'dE!CAUs
} *TacVp
N;)Y+amg^
y1zNF$<q
public void run() JjH#,@'.
{ {u/G!{N$
while(nStartPos < nEndPos && !bStop) -]!m4xvK
{ v7;zce/~
,}9G|$
*)PCPYB^
try{ (6Ssk4
URL url = new URL(sURL); *Ey5F/N}$H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,(%?j]_P2
httpConnection.setRequestProperty("User-Agent","NetFox"); <4caG2~q
String sProperty = "bytes="+nStartPos+"-"; m~upTQz
httpConnection.setRequestProperty("RANGE",sProperty); 8|\0\Wd;vu
Utility.log(sProperty); ct,Iu+HJ
m5m'ByX(*
Y5J}*`[Mr
InputStream input = httpConnection.getInputStream(); ,d^ze=
//logResponseHead(httpConnection); &3jq'@6
[gZz'q&[)
hWzjn5w3
byte[] b = new byte[1024]; .kv/db
int nRead; $}{u6*u.,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) urJ>dw?FI
{ O{0TS^
nStartPos += fileAccessI.write(b,0,nRead); i0,'b61qE
//if(nThreadID == 1) lu]Z2xSv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,34|_
} iG:9uDY
]Bpdb'
QQQ3U
Utility.log("Thread " + nThreadID + " is over!"); |2!!>1k
bDownOver = true; XxN=vL&m
//nPos = fileAccessI.write (b,0,nRead); Y}'8`.
} ?A!Lh,
catch(Exception e){e.printStackTrace ();} Xp(e/QB
} ;(]O*{F7k
} RoL5uha,l
Bl)znJ^
=44hI86
//打印回应的头信息 vcsrI8+
public void logResponseHead(HttpURLConnection con) xB&kxW.;
{ H9c
for(int i=1;;i++) @uIY+_E40g
{ lq4vX^S
String header=con.getHeaderFieldKey(i); Lk%u(duU^
if(header!=null) 6$]p;}#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _h@s)"
Utility.log(header+" : "+con.getHeaderField(header)); Hh/Z4`&yi
else 5if4eitS
break; iSm5k:7
} mw^Di
} SUSam/xeg"
x~7_`=}rO
>DHpD?Pm!
public void splitterStop() aJnZco6
{ =cy;{2S'p
bStop = true; (thDv rT@2
} ?DAW~+,!7o
P'4oI0Bw
jU4*fzsZI
} SvlS4C
hq5=>p
pq \M;&
/* /0w?"2-
**FileAccess.java Yl65|=ne
*//文件访问(定位，写) 410WWR&4_
package NetFox; 8J&K_JC^
import java.io.*; U}c[oA
a59l"b
8QFn/&Ql$B
public class FileAccessI implements Serializable{ E8-8E2i,
/ae]v+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ELx?ph-9
RandomAccessFile oSavedFile; m?Gb5=qo
long nPos; A+JM* eB
\O]1QM94Y
<K8$00lm
public FileAccessI() throws IOException ` ,B&oV>
{ kg2?IL
this("",0); ?}QHEk:H
} }m?1IU%q
;l]OmcL
|+?ABPk"
public FileAccessI(String sName,long nPos) throws IOException =y3gnb6
{ w|6;Pf~1y)
oSavedFile = new RandomAccessFile(sName,"rw"); a'/yN{?p
this.nPos = nPos; 7e,EI9?.
oSavedFile.seek(nPos); =4RBHe8`
} B3 mD0
7=.}484>J
/MS*_
public synchronized int write(byte[] b,int nStart,int nLen) {C=d9z~:
{ 4KB)UPW
int n = -1; yFt'<{z[nL
try{ cZ(7/Pl
oSavedFile.write(b,nStart,nLen); b;!oPT
n = nLen; st;.Po[h
} Fm\ h883\
catch(IOException e) .uAOk0^z
{ /2,s-^
e.printStackTrace (); sje}E+{[
} E%g_O_
'ADaz75`*r
{u BpM9KT
return n; 7)S;VG k
} U=<E,tM
MC5M><5\
k~ZwHx(%S
} e+"rL]
opz.kP[e,
H6<\7W89y
/* uJ S+;H
**SiteInfoBean.java jW6~^>S
*/ q#v&&]N=
package NetFox; ~o:lh],~
!<"H73?fl
-9"hJ4
public class SiteInfoBean { f-5vE9G3y7
^>?gFvWB%
5 ^}zysY`
private String sSiteURL; //Site's URL Im{I23.2
private String sFilePath; //Saved File's Path _oxc~v\<
private String sFileName; //Saved File's Name <Bc J;X/
private int nSplitter; //Count of Splited Downloading File mw<LNnT{8
5S'89 r3m
6MfjB@
public SiteInfoBean() ;4nz'9+
{//nSplitter的缺省值为5 EthnI7Y
//default value of nSplitter is 5 clz6;P
this("","","",5); NQq$0<7.=W
} GXC:~$N
zJ42%0g
9:^SnHAa
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Pms"YhyZ7
{ [((P,v*
sSiteURL= sURL; /?l@7
sFilePath = sPath; be`\O
sFileName = sName; |$`LsA.
this.nSplitter = nSpiltter; u"-q"0
X)d7y
tk4~ 8
} _X{ihf
B8z3W9
rmc0dm&l]
public String getSSiteURL() heiIb|z
{ ml7]sN(
return sSiteURL; EBS04]5ul
} EzK,SN#
RE`XyS0Q
<5MnF
public void setSSiteURL(String value) `,ZsKxI
{ M xUj7ae
sSiteURL = value; )sG`sET]`f
} F+Og8^!
+DS_'Tmr
epi{Ayb
public String getSFilePath() *M;!{)m?
{ -~eNC^t;W
return sFilePath; !+&"y K@J
} \{L!hAw
WE\912j
{:c*-+?
public void setSFilePath(String value) 6/B"H#rN
{ kpi)uGvGUA
sFilePath = value; 92+LY]jS
} 17[7)M88
)BudV zg
7{j9vl6
public String getSFileName() +`l>_u'
{ )r-t$ L
return sFileName; :.6kXX'~
} 'mj0+c$
1HxE0>
j}Lt"r2F
public void setSFileName(String value) |xyN#wi
{ JnH>L|G{;%
sFileName = value; 1Qui.],c
} PiXegh WH
kL,bM.;
jx a?
public int getNSplitter() 'E+Ty(ED5
{ TYW$=p|
return nSplitter; ext`%$ U7
} l'T3RC,\
oEvXZ;F@.
QPgM<ns
public void setNSplitter(int nCount) :P<} bGN
{ ac6Lv}w_
nSplitter = nCount; =ZjF5,@
} x3O$eKy\|5
} @U'I_`LL
%CJgJ,pk>
TO.?h!
/* qQ[&FjTO`
**Utility.java (1gfb*L
*/ sL]KBux
package NetFox; '`=z52
,TaaXI
-qz;
public class Utility { -m)N~>{qS
AB40WCu]*
{\ vj":
public Utility() o:jLM7$=
{ B P%>J^
Ss+e*e5Ht
(D F{l?4x-
} Bh?K_{e
i6M_Gk}
//线程睡眠 Au,xIe!t
public static void sleep(int nSecond) msOk~ZPE6\
{ OoTMvZP[
try{ =z^v)=uhp
Thread.sleep(nSecond); G\&4_MS
} hX(:xc
catch(Exception e) :$j6
{ #`)zD"CO
e.printStackTrace (); W-zD1q~0?
} _P.+[RS@
} p*E_Po
o,(MB[|hQ
//日志 WgPpW!`
public static void log(String sMsg) K4NB#
{ #FKo:id`K
System.err.println(sMsg); o^%4w>|
} Q.Uyl:^PxU
0\#uxzdhJ
=qiX0JT
public static void log(int sMsg) l/0TNOA
{ 9{_D"h}}
System.err.println(sMsg); X>l
} @1ZLr
} ?kvkkycI
#R v&b@K
\xJTsdd
/* /Ps}IW
**TestMethod.java ujsJ;\c
*/ '|Dm\cy
package NetFox; VXlTA>a }
bSsX)wHm
]@_M)[ x
public class TestMethod { A$vCm
'p,QI>
'aMT^w4if)
public TestMethod() I@~hz%'
{ ///xx/weblogic60b2_win.exe s,>1n0a
try{ Z'p7I}-qr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5-lcz)DO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J&4LyIpQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); +ew2+2
fileFetch.start(); ,!U5;
} ]^:l?F\h
catch(Exception e){e.printStackTrace ();} uCuXY#R+
@bU(z$eB
[Dd?c,5AD
} 95jJ"4a+
kuq3QW<
o!EPF-:
public static void main(String[] args) qV0C2jZ2
{ %cJ]Ds%V
new TestMethod(); @q2If{Tk
} ]>-#T
} %tiFx:F+
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