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)); @*YF!LdU{M
} 4>jHS\jc
for(int i=0;i<nEndPos.length-1;i++) k4K. mlIO
{ [gmov)\c
nEndPos = nStartPos[i+1]; T7,]^ 1
} ,TQec:B
nEndPos[nEndPos.length-1] = nFileLength; t{]Ew4Y4%O
} kXwAw]ogN
} yW|J`\`^T
ka9@7IFM
u5oM;#{@-
//启动子线程 6Rn?pe^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %GhI0F #
for(int i=0;i<nStartPos.length;i++) YhN<vZ}U!~
{ |U|>YA1[b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), + `|A/w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |UXSUP @s
nStartPos,nEndPos,i); c;VqEpsbl
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Dp([r
fileSplitterFetch.start(); tAAMSb9[d
} >O-KJZ'GV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E!9WZY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3a?-UT!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #f2Ot<#-
nEndPos = " + nFileLength); Ek{QNlQ]4
// fileSplitterFetch[nPos.length-1].start(); DSU8jnrL
o}rG:rhIh
f% pT-#
//等待子线程结束 M=^d
//int count = 0; }>@\I^Xm,
//是否结束while循环 @_+aX.,
boolean breakWhile = false; `8!9Fp
4?R979
*S,~zOYN
while(!bStop) u} ot-!}Q
{ TjUwe@&Rw
write_nPos(); AP&//b,^M
Utility.sleep(500); XY"b90
breakWhile = true; Z1HH0{q-A
:PO./IBX
xo[o^go
for(int i=0;i<nStartPos.length;i++) /|?$C7%a\D
{ f^F;`;z
if(!fileSplitterFetch.bDownOver) P 45Irir
{ Nfa&r
breakWhile = false; [}L~zn6>?a
break; ,H]%4@]|o
} sO.MUj;
} FIq'W:q:
if(breakWhile) meX2Y;
break; _Sr}3
#V>R#Oh}
MmT/J1zM
//count++; &6sF wK
//if(count>4) ER"69zQg|2
// siteStop(); ?NMk|+
} ^DYS~I%s
BSm"]!D8*
{-Y;!
System.err.println("文件下载结束！"); <M:BN6-yG
} c-+NWC
catch(Exception e){e.printStackTrace ();} `zQuhD 8W
} SQN?[v
t13V>9to
[^hW>O=@TN
//获得文件长度 dNe!X0[
public long getFileSize() 6 U.Jaai:
{ &n<YmW?"
int nFileLength = -1; pD{OB
try{ h@%Xy(/m'
URL url = new URL(siteInfoBean.getSSiteURL()); uxfh?gsL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F6\{gQ<E
httpConnection.setRequestProperty("User-Agent","NetFox"); \YvG+7a
:c*"Dx'D
o 4F'z
int responseCode=httpConnection.getResponseCode(); @)Vpj\jM-C
if(responseCode>=400) $TUYxf0q
{ {nmG/dn{
processErrorCode(responseCode); Y% iqSY
return -2; //-2 represent access is error U)(R4Y6 v
} zx#Gm=H4
3%POTAw%
|1@O>GG
String sHeader; ktyplo#F
f{9+,z
V(S7mA:T
for(int i=1;;i++) _}R$h=YD
{ x1gS^9MqCB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (5$Ge$
//Utility.log(in.readLine()); Z=Y29V8
sHeader=httpConnection.getHeaderFieldKey(i); XCM!8x?K
if(sHeader!=null) p(yv
{ | Y:`>2ev
if(sHeader.equals("Content-Length")) 3bRxV @0.
{ =4_}.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); NpVL;6?7T
break; do" m=y
} 6P{bUom?
} +/B
else <'=!f6Wh
break; @gP*z6Z
} D.Ke
} C%4ed#
catch(IOException e){e.printStackTrace ();} ,M.C]6YMr
catch(Exception e){e.printStackTrace ();} P-X|qVNK1Z
Qa2h#0j
>DRxF5b{
Utility.log(nFileLength); S*l/ Sa@
k+_>`Gre}
;+75"=[YT
return nFileLength; i#:To |\u
} ^; KCE
INndTF
,i_+Z |Ls
//保存下载信息（文件指针位置） )"TVR{I%B
private void write_nPos() &N.pW=%,N
{ MZ38=nJ
try{ uzp\V 39
output = new DataOutputStream(new FileOutputStream(tmpFile)); XL*M#Jx
output.writeInt(nStartPos.length); SkDr4kds
for(int i=0;i<nStartPos.length;i++) (aYu[ML
{ M~zI;:0O
// output.writeLong(nPos); NVzo)C8kb
output.writeLong(fileSplitterFetch.nStartPos); nf pO
output.writeLong(fileSplitterFetch.nEndPos); v7(7WfqP
} 56C8)?
output.close(); %Z6Q/+#fn
} Lv+{@)
catch(IOException e){e.printStackTrace ();} jwwRejNV
catch(Exception e){e.printStackTrace ();} |?KYY0
} fDr$Wcd~
[>NMuwtG
&l cfX\y
//读取保存的下载信息（文件指针位置） Pz50etJ
private void read_nPos() gb,ZN^3<-
{ -gGw_w?)(
try{ >|S@twy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FKL4`GEm
int nCount = input.readInt(); `:'ciY|%b
nStartPos = new long[nCount]; ,OlS>>,
nEndPos = new long[nCount]; ;[o:VuTs
for(int i=0;i<nStartPos.length;i++) A^}#
{ j~_iv~[
nStartPos = input.readLong(); =.s0"[%
nEndPos = input.readLong(); 0$Tb5+H5
} 8K2@[TE=5
input.close(); 1*A^v
} <IWg]AJT:
catch(IOException e){e.printStackTrace ();} qBF|' .$^
catch(Exception e){e.printStackTrace ();} TQb/lY9*
} & *tL)qKDc
{zZ)JWM<w
`Ku:%~$/
private void processErrorCode(int nErrorCode) 1Z0Qkd(
{ :PV3J0pB~
System.err.println("Error Code : " + nErrorCode); Wpf~Ji6||
} sm"Rp~[i
~5Fx[q
io\t>_
//停止文件下载 7x.j:{2
public void siteStop() 4wv0~T$;x
{ q-CgXwU
bStop = true; "~ =O`5V
for(int i=0;i<nStartPos.length;i++) e 6wevK\
fileSplitterFetch.splitterStop(); AxEdQRGk
Y*b$^C%2
h>>~Bi
} !]?kvf-3e
} V.8Vy1$
//负责部分文件的抓取 7 2i&-`&4
**FileSplitterFetch.java HJb^l 4Q
*/ ^PC;fn,I
package NetFox; .|CoueH
,f%4xXI
qsEFf(9G
import java.io.*; mph9/ %]S
import java.net.*; VI|2vV6?
'h;qI&
;>/Mal
public class FileSplitterFetch extends Thread { c0l?+:0M
` >>]$ZJ
XFWE^*e=B
String sURL; //File URL H/*slqL
long nStartPos; //File Snippet Start Position 9s!R_R&W.
long nEndPos; //File Snippet End Position V:t{mu5j
int nThreadID; //Thread's ID `*0VN(gf'
boolean bDownOver = false; //Downing is over p<pGqW
boolean bStop = false; //Stop identical Y_C6*T%
FileAccessI fileAccessI = null; //File Access interface +t-_FbFh3D
a;a1>1
YHY*dk*|C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yXIJeo"
{ ,+Ocb-*
this.sURL = sURL; ./zzuKO8XK
this.nStartPos = nStart; v.sjWF
this.nEndPos = nEnd; ~Hd*Xl
nThreadID = id; 6uUzky
fileAccessI = new FileAccessI(sName,nStartPos);//定位 iZ/iMDfC
} UCj<FN `
3&"uf9d
yK"HHdYTV
public void run() ' Qlj"U
{ 3me&isKL
while(nStartPos < nEndPos && !bStop) fGA#0/_`
{ 4\ElMb[]
MOytxl:R
JSylQ201
try{ *2.h*y'u
URL url = new URL(sURL); hpbi!g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +~:OUR*>
httpConnection.setRequestProperty("User-Agent","NetFox"); wSM(!:on5
String sProperty = "bytes="+nStartPos+"-"; PQ;9iv
httpConnection.setRequestProperty("RANGE",sProperty); ']sjW'~
Utility.log(sProperty); (7&b)"y
)lz)h*%#
?|Z~mE
InputStream input = httpConnection.getInputStream(); ~e)"!r
//logResponseHead(httpConnection); {KK/mAp{
]Nssn\X7
E{^W-
byte[] b = new byte[1024]; f;OB"p
int nRead; Brd9"M|d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9@mvG^
{ 48 0M|^
nStartPos += fileAccessI.write(b,0,nRead); 6kAGOjO
//if(nThreadID == 1) !I&,!$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `}L{gssv
} M '%zA;Wl
AOwmPHEL
CY*GCkH
Utility.log("Thread " + nThreadID + " is over!"); 2AMb-&po&f
bDownOver = true; 0r i
//nPos = fileAccessI.write (b,0,nRead); _I3v"d
} p&4n"hC
catch(Exception e){e.printStackTrace ();} .A_R6~::
} -0]%#(E%`h
} !g)rp`?
^ uwth
MR5[|kHJT
//打印回应的头信息 `ueOb
public void logResponseHead(HttpURLConnection con) CvEIcm=t
{ Nz*,m'-1e
for(int i=1;;i++) i\DU<lD5VN
{ N_Zd.VnY
String header=con.getHeaderFieldKey(i); lF40n4}
if(header!=null) yOAC<<Tzus
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oQ*LP{M
Utility.log(header+" : "+con.getHeaderField(header)); ""_G4{
else <$a-.C5
break; a<E9@
} B(} 'yY@%u
} ,q7FK z{
_ yDDPuAi
R9"}-A
public void splitterStop() 8Z"f"
{ :)T*:51{#
bStop = true; x%[NK[^&
} 7fSNF7/+
TiG?r$6v%
nG{o$v_|
} D/;[x{;E
NpKyrXDJv
02NVdpo[wU
/* 4PkKL/E
**FileAccess.java UWK|_RT6SA
*//文件访问(定位，写) +9pock
package NetFox; ^Pu:&:ki
import java.io.*; s_+.xIZ
qK2jJ3)>
rl$"~/ oz
public class FileAccessI implements Serializable{ sX3qrRY
G)M! , Q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1wdc4>
RandomAccessFile oSavedFile; piuM#+Y\'S
long nPos; | WTWj
L%<]gJtrO
.}Ys+d1b9c
public FileAccessI() throws IOException uqa pj("
{ V8&'dhuG
this("",0); aSxDfYN=R
} ,=c(P9}^
[u^ fy<jdp
TA:uB[Ji
public FileAccessI(String sName,long nPos) throws IOException gu~R4@3
{ AkdO:hVtG
oSavedFile = new RandomAccessFile(sName,"rw"); F7nwVDc*
this.nPos = nPos; C]l)Pz$
oSavedFile.seek(nPos); |!7leL
} 7 b(
9ZatlI,
I|>.&nb
public synchronized int write(byte[] b,int nStart,int nLen) h(J$-SUs
{ RP[`\
int n = -1; -1NR]#P'
try{ 2QEH!)lvr
oSavedFile.write(b,nStart,nLen); L+T7Ge q
n = nLen; #CAZ}];Qx
} 'irwecd8
catch(IOException e) .3XiL=^~Qp
{ [e@m-/B
e.printStackTrace (); 1ah,Zth2
} PApr8Xe
+ @|u8+
5L~lF8
return n; m .(\u?J
} ?m7i7Dz
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{hN<Ot
} M8\/[R\
&m[}%e%~0
/-m)
/* %[9ty`UE
**SiteInfoBean.java }NGP!
*/ h8Oj E$ H
package NetFox; '@w'(}3!3R
) R5j?6}xF
V?)V2>]
public class SiteInfoBean { kTT%< e
=3SJl1w1
V=5*)i/
private String sSiteURL; //Site's URL L]"$dF
private String sFilePath; //Saved File's Path 9n_RkW5g
private String sFileName; //Saved File's Name x%goyXK
private int nSplitter; //Count of Splited Downloading File YO?o$Hv16
i^Jw`eAmT
,O-_Pv
public SiteInfoBean() F1B/cd
{//nSplitter的缺省值为5 w'$>E4\
//default value of nSplitter is 5 iQG]v[$
this("","","",5); Z1+Ewq3m
} omy3<6
jOGiT|A
hJSWh5]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ot!m=s
{ qTwl\dcncC
sSiteURL= sURL; Bz>f
sFilePath = sPath; "cly99t
sFileName = sName; y!R9)=/M
this.nSplitter = nSpiltter; _K'Y`w']
J&JZYuuf
"-MB U
} O\Z!7UQ$
9kqR-T|Q
OkISRj'!U
public String getSSiteURL() -O=xgvh"
{ v''J@F7
return sSiteURL; TqV^\C?
} H_x}-
eX}aa0
T@#?{eA
public void setSSiteURL(String value) &sBD0R(a
{ %_B2/~
sSiteURL = value; gN[t
} ZPq.|6&
'o0o.&/=
&OXx\}>MW
public String getSFilePath() y x#ub-A8
{ QOrMz`OA
return sFilePath; I!1+#0SG
} #;@I.
3K/tB1
JgKhrDx
public void setSFilePath(String value) /Lm~GmPt
{ ]F>#0Rdc
sFilePath = value; vZ$E [EG}
} >m<T+{`
(0`w.n
c9CFGo?)N
public String getSFileName() ;E.f%
{ Ef?|0Gm
return sFileName; R-OO1~W=
} IqsUtWSp
a'Zw^g
41+WIa L
public void setSFileName(String value) Yh@2m9
{ Y{#*;p*I
sFileName = value; Q{'4,J-w
} QUvSeNSp
zF{~Md1
o:3(J}
public int getNSplitter() :2 :VMIa
{ JEWc{)4QD
return nSplitter; Fo;:GX,b
} -%%Xx5D
3^fwDt}
birc&<
public void setNSplitter(int nCount) P?n4B \!
{ dtfOFag4_
nSplitter = nCount; y0&vsoT
} 9rT^rTV
} !]D`|HoW
RjO0*$>h
YX)Rs Vf
/* Wwg<- 9wAJ
**Utility.java yqL"YD
*/ =mPe wx'
package NetFox; 2QAP$f0Ln
"$o>_+U
>qr/1mW
public class Utility { _`^AgRE
Tbv w?3
"p|.[d
public Utility() *x]*%
{ ]$9y7Bhj.
Rf>)#hn%
4KR`
} ~I;x_0iY4
;fW~Gb?"
//线程睡眠 fsw[R0B
public static void sleep(int nSecond) gCiM\Qx
{ i$6rnS&C
try{ X;UEq]kcmn
Thread.sleep(nSecond); Z}>F V~4
} S$$SLy:P
catch(Exception e) GQhy4ji'z
{ ry=8Oq&[~
e.printStackTrace (); ~TS!5Wiv
} wuYak"KX
} <;?1#ok
& /T}
//日志 I%Yq86
public static void log(String sMsg) !uIY,
{ P!IA;i
System.err.println(sMsg); r63l(
} Z4As'al
U5~aG!E
aQ\SV0PI
public static void log(int sMsg) m;{HlDez
{ Tsb}\
System.err.println(sMsg); {6RA~
} 'Rsr*gX#
} v^s?=9
7.ein:M|CB
N'&>bO?@`
/* $|J+
**TestMethod.java wEX<[#a-
*/ {^N,$,Ab.
package NetFox; G/#<d-}_
x"RF[d
F {L#
public class TestMethod { p!=8Pq.
<X4f2z{T{@
:{Z%dD
public TestMethod() aZ\Z7(
{ ///xx/weblogic60b2_win.exe 3gVU#T[[
try{ 4~$U#$u_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5WRqeSGh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sn^ 3xAF
SiteFileFetch fileFetch = new SiteFileFetch(bean); =EA @
fileFetch.start(); &K9RV4M5
} >yT1oD0+x
catch(Exception e){e.printStackTrace ();} &1^~G0Rh\
SIR2 Kc0
h>[ qXz
} 8$47Y2r@
;'V[8`Z@
w~crj$UM
public static void main(String[] args) sg}<()
{ iiJT%Zq`#
new TestMethod(); u #}1 M
} <kwF<J
} 7SYe:^Dx
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