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)); ZHN}:W/p
} L"x9O'U
for(int i=0;i<nEndPos.length-1;i++) 9{- Sa
{ ^MczumG[
nEndPos = nStartPos[i+1]; KQulz
} 7dh--.i
nEndPos[nEndPos.length-1] = nFileLength; 5^0K5R6GQf
} }uo.N
} XEpwk,8*g
%YLyh?J
gI5Fzk@:
//启动子线程 ~i5t1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |]=s
for(int i=0;i<nStartPos.length;i++) z$]HZ#aRE
{ 6>e YG<y{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y&(R1Y75
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mA" 82"
nStartPos,nEndPos,i); Op 0Qpn
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F7N4qq1
fileSplitterFetch.start(); k1sR^&{l
} xA#'%|"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UEh-k"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ];7/DM#Np
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \EC7*a0
nEndPos = " + nFileLength); $?Yw{%W
// fileSplitterFetch[nPos.length-1].start(); g| M@/Dl
EwuBL6kN
O ]Stf7]%;
//等待子线程结束 >G<.^~o
//int count = 0; jPyhn8Vw
//是否结束while循环 vkg."G:=
boolean breakWhile = false; 6JZ$;x{j
(.J8Q
(U@uJ
while(!bStop) rxM)SC;P
{ r<XlIi
write_nPos(); -_xC,dwK
Utility.sleep(500); JzZ9ua
breakWhile = true; |@lVFEl]
x}*Y =Xh
^{(i;IVG
for(int i=0;i<nStartPos.length;i++) @ZFU< e$!
{ )9mUE*[
if(!fileSplitterFetch.bDownOver) %m0x]
{ C~([aH@-I
breakWhile = false; mzoNXf:x
break; H,5##@X
} K-f\nr
} z6 A`/ jF}
if(breakWhile) $v*0\O
break; M~ ^ {S[o
D|BP]j}6
_Sxp|{H0
//count++; 2xJT!lN
//if(count>4) 0-{l4;o
// siteStop(); {Vj25Gt
} A1u|L^
I-`qo7dQ_S
qf qp}g\
System.err.println("文件下载结束！"); dS[="Set
} `+go| 5N2
catch(Exception e){e.printStackTrace ();} -$J%.fdPs
} T1}9^3T?{
N;BS;W5I
_Mis-K:]{?
//获得文件长度 e2xqKG
public long getFileSize() UIl^s8/
{ b2vc
int nFileLength = -1; LN?b6s75U
try{ At#'q>Dn
URL url = new URL(siteInfoBean.getSSiteURL()); koizk&)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )5M9Ro7
httpConnection.setRequestProperty("User-Agent","NetFox"); VN1a\
ecI[lB
BkTGH.4G%
int responseCode=httpConnection.getResponseCode(); aF'9&A;q
if(responseCode>=400) pdrF/U+
{ # Y*cLN`Y7
processErrorCode(responseCode); F ;m1I+;
return -2; //-2 represent access is error "w\Iz]
} q;kN+NK64
|5}~n"R5
wPl!}HNf
String sHeader; ]v^;]0vcr
vkXdKL(q
F;IG@ &
for(int i=1;;i++) L|3wGY9E
{ 5[Ryc[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n+EK}=DK
//Utility.log(in.readLine()); g8{?;
sHeader=httpConnection.getHeaderFieldKey(i); Ass8c]H@
if(sHeader!=null) @lau?@$ja
{ gJyFt8Z<
if(sHeader.equals("Content-Length")) $UZ4,S?V
{ "$Wi SR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cs?@Ri=g
break; &B^vHH
} vYD>m~Qc^
} 1D fB9n
else *mM+(]8US
break; }[u9vZL
} eXaa'bTx
} m<BL/7
catch(IOException e){e.printStackTrace ();} dm Lgt)-t
catch(Exception e){e.printStackTrace ();} {Y9m;b,X
,~Y5vnaOQ
xw5E!]~D
Utility.log(nFileLength); DlR&Lnv
#;RP ?s
$J#}3;a
return nFileLength; icF -`m
} yKO84cSl
a$MMp=p
UcMe("U
//保存下载信息（文件指针位置） i&^?p|eKa
private void write_nPos() HnVUG4yZTD
{ `5`Pv'`
try{ #](k,% 2
output = new DataOutputStream(new FileOutputStream(tmpFile)); n>\BPiz
output.writeInt(nStartPos.length); ^sq3@*hCw
for(int i=0;i<nStartPos.length;i++) "w`f>]YLA
{ sHe:h XG'
// output.writeLong(nPos); =MG
output.writeLong(fileSplitterFetch.nStartPos); yov:JnWo
output.writeLong(fileSplitterFetch.nEndPos); _f,q8ZkSr
} .9WUp>
output.close(); c?d+>5"VX
} Y,?
catch(IOException e){e.printStackTrace ();} -,96Qg4vI
catch(Exception e){e.printStackTrace ();} amGQ!$] %#
} BoP%f'0N
N7Z&_$Bx
T}2a~
//读取保存的下载信息（文件指针位置） -nO('(t
private void read_nPos() x}1(okc
{ "twV3R
try{ ]xf{.z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Z8kO*LYv
int nCount = input.readInt(); W #qM$
nStartPos = new long[nCount]; 5Zn3s()
nEndPos = new long[nCount]; F& H~JJ
for(int i=0;i<nStartPos.length;i++) _Ux>BJmP
{ >S{1=N@Ev=
nStartPos = input.readLong(); ^k^%w/fo
nEndPos = input.readLong(); U*k$pp6\b~
} d[rxmEXht
input.close(); )sB`!:~HjP
} [fR<#1Z
catch(IOException e){e.printStackTrace ();} jzEimKDE's
catch(Exception e){e.printStackTrace ();} 5.VA1
} ~AK!_EOs`
h+.^8fPR
l},px
private void processErrorCode(int nErrorCode) :":W(O
{ ,X\z#B
System.err.println("Error Code : " + nErrorCode); 5yxZ 5Ni!
} zK:/ 1
":"M/v%F
QE)g==d
//停止文件下载 'L3 \I
public void siteStop() |}q0G~l
{ Os@ofnC
bStop = true; S~/iHXm
for(int i=0;i<nStartPos.length;i++) W .Hv2r3
fileSplitterFetch.splitterStop(); p$[*GXR4
"VcGr#zW
_vU,avw
} 348Bu7':
} 1oX"}YY1
//负责部分文件的抓取 30<dEoF
**FileSplitterFetch.java {,s:vPoiA
*/ r*+9<8-ZX<
package NetFox; R"O9~s6N
KDQux
S~Q7>oNm
import java.io.*; KM0#M'dXy
import java.net.*; >t*zY~R.
3\mFK$#sr
Nob(bD5SpE
public class FileSplitterFetch extends Thread { _FdWV?
k,?Y`s
}E/L:
String sURL; //File URL N.-Ryj&9
long nStartPos; //File Snippet Start Position )-jvp8%BK
long nEndPos; //File Snippet End Position &|{K*pNa
int nThreadID; //Thread's ID kN]#;R6
boolean bDownOver = false; //Downing is over B0R[f
boolean bStop = false; //Stop identical }JlQQ
FileAccessI fileAccessI = null; //File Access interface Rut6m5>
{v`wQM[
SxH}/I|W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F=P|vYL&&
{ %eT/:I
this.sURL = sURL; dOiy[4s
this.nStartPos = nStart; #4cuNX5m%
this.nEndPos = nEnd; Yhlk#>I
nThreadID = id; #d|.BxH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >nr1|2
} Kw?,A
0q`'65 lx
MESQAsx%
public void run() &12aI|u^<
{ 'GW@P
while(nStartPos < nEndPos && !bStop) %%k[TO
{ ?$s2]}v
*i$+i
T+.wJW:jh
try{ BO[A1'>
URL url = new URL(sURL); <XLATS8Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !8A5Y[(XD
httpConnection.setRequestProperty("User-Agent","NetFox"); =_,OucKkYG
String sProperty = "bytes="+nStartPos+"-"; ;hZ(20
httpConnection.setRequestProperty("RANGE",sProperty); T%]: tDa
Utility.log(sProperty); *aT!|;
c2F`S1Nu<
.#Sd|C]R7
InputStream input = httpConnection.getInputStream(); oNEU?+
//logResponseHead(httpConnection); t(_XB|AKm
mV4} -
z&t6,0q`5
byte[] b = new byte[1024]; 9g*~X;`2
int nRead; S%T1na^x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U>I#f
{ -pjL7/gx
nStartPos += fileAccessI.write(b,0,nRead); O42An$}
//if(nThreadID == 1) :8)4:4$^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j1d=$'a "
} v~xG*e
C<7J5
Cy2X>Tl"<E
Utility.log("Thread " + nThreadID + " is over!"); +_ G'FD
bDownOver = true; :?^(&3;
//nPos = fileAccessI.write (b,0,nRead); >l7 o/*4
} J$P]>By5:
catch(Exception e){e.printStackTrace ();} nh8h?&q|
} xGH%4J\
} TfxKvol'
q6DhypB
]pGr'T~Gj
//打印回应的头信息 !#?tA/t@
public void logResponseHead(HttpURLConnection con) {C6Yr9
{ u9&p/qMx2
for(int i=1;;i++) $i2gOz
{ C1nQZtF R
String header=con.getHeaderFieldKey(i); Vw#07P#A
if(header!=null) )a6i8b3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A} "*`y
Utility.log(header+" : "+con.getHeaderField(header)); F 4hEfO3
else ,L^L uw'7
break; [v&_MQ
} M6I1`Lpf
} J|b1 K]
2V0R|YUt
:I7MP
public void splitterStop() mB :lp=c`
{ uu/MXID
bStop = true; 1,mf]7k$
} 5N6%N1
L%<1C\k
{jl4`
} 7+fik0F
Vz,WPm$I
5_O.p3$tV
/* M-Js"cB[
**FileAccess.java *rbH|o8
*//文件访问(定位，写) Gmwn:
package NetFox; O{4m-;
import java.io.*; _Nj;Ni2rD
JDs<1@\
dYsqF 3f
public class FileAccessI implements Serializable{ '"TBhisky
ALG #)$|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |fA[s7)
RandomAccessFile oSavedFile; #Q{6/{bM&J
long nPos; `K@
kz&)a>aA
RsY<j& f
public FileAccessI() throws IOException *0iP*j/]
{ ]juXm1)>W1
this("",0); mkWIJH
} ecFI"g
}C'z$i( y
h{! @^Q
public FileAccessI(String sName,long nPos) throws IOException o1Xk\R{
{ *=I#VN*_<.
oSavedFile = new RandomAccessFile(sName,"rw"); tSm|U<
this.nPos = nPos; ?T^$,1-
oSavedFile.seek(nPos); !98s[)B:
} "qF&%&#r'
Q`oi=OYB
(zhmZm
public synchronized int write(byte[] b,int nStart,int nLen) NLdUe32A
{ )sL:iGU
int n = -1; 9+/<[w7
try{ >Z3}WMgBN
oSavedFile.write(b,nStart,nLen); a@ lK+t
n = nLen; `$i`i'S
} $$8"i+,K
catch(IOException e) ~@-Az([H
{ pymT-
e.printStackTrace (); ?>,aq>2O$
} UA/3lH}
[A3hrSw
qH-dT,`"{
return n; v/^2K,[0>
} ou(9Qf zN
b\^.5SEw
|mKd5[$
} P#yS]F/
dJ|]W|q<
@z2RMEC~
/* 0nl)0|?Az
**SiteInfoBean.java ./6L&?*`~;
*/ {g);HnmPN
package NetFox; o30PI
W9u(
ad"&c*m[
public class SiteInfoBean { GWhb@K
bg$e80
8RocObY_W
private String sSiteURL; //Site's URL N.VzA 6C
private String sFilePath; //Saved File's Path )ei+ewVZ
private String sFileName; //Saved File's Name PvA%c<z
private int nSplitter; //Count of Splited Downloading File mp5]=6~:m
]`|bf2*eA
pZWp2hj{X
public SiteInfoBean() ."H5.'
{//nSplitter的缺省值为5 gHm^@
//default value of nSplitter is 5 HFf| >&c&
this("","","",5); m=n V$H
} jm*v0kNy
D}_\oE/n
M r@M~ -
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8HWY]:|oh
{ "#p)Z{v"!
sSiteURL= sURL; EKDv3aFQZ#
sFilePath = sPath; |_ ;-~bmb
sFileName = sName; [y:6vC
this.nSplitter = nSpiltter; u2F 3>s
GHoPv-#
6%5A&&O(b
} 9aXm}
.2u%;)S
LtNG<n)_BH
public String getSSiteURL() gzuM>lf*{
{ m2 OP=z@)
return sSiteURL; JM M\
} AA@J~qd u
%5uuB4P&|$
MenI>gd?
public void setSSiteURL(String value) O[-wm;_(=*
{ 8^HMK$
sSiteURL = value; 2sf/^XC1
} c !5OK4+Z
id*UTY Tg
[]u!piW
public String getSFilePath() 8XTVpf4
{ J4x1qY)Y&v
return sFilePath; :yw0-]/DD
} $3FFb#r
;B tRDKn
}z[O_S,X
public void setSFilePath(String value) rYc?y
{ /LJ?JwAvg5
sFilePath = value; bk"` hq
} -BB5bsjA
JSO>rpO
rs!J<CRq
public String getSFileName() - 5A"TNU
{ |~'{ [?a*
return sFileName; \ar.(J
} koaH31Q
ZfMJU
XD*$$`+#
public void setSFileName(String value) B9+oI cO
{ P 0,]Ud
sFileName = value; 9B<y w.
} kigc+R
qk<tLvD_'
Th@L68
public int getNSplitter() yzXwxi1#
{ l=kgRh
return nSplitter; jz/@Zg",
} O^ f[ugs
`qX'9e3VP+
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public void setNSplitter(int nCount) '"=C^f
{ =TyN"0@
nSplitter = nCount; ^W'\8L
} e}7qZ^
} AD~\/V&+
Px)VDs=k
lQ)ZsFs=
/* -O-_F6p'D
**Utility.java BYwG\2?~
*/ ^${-^w@,%V
package NetFox; 011 _(v
O4( Z%YBe
v%B^\S3)
public class Utility { AvhmN5O=
U<o,`y[Tn
tpA7"JD
public Utility() u5%.T0 P
{ Jw9|I)H
1jQz%^~
XnV|{X%]U
} < R0c=BZ>
pH)V:BmJ
//线程睡眠 8`'_ckIgr
public static void sleep(int nSecond) RYmk6w!w
{ 1G$kO90
try{ B*,9{g0m/
Thread.sleep(nSecond); /ptIxe
} i7*4hYY
catch(Exception e) FWPkvL
{ 5GC{)#4
e.printStackTrace (); nwW`Q>+#U
} 0 R^Xn
} HOXqIZN85
5Sk87o1E(d
//日志 `P"-9Ue=
public static void log(String sMsg) R '"J{oR
{ |jc87(x<
System.err.println(sMsg); 7?/ Fr(\
} vhdT"7`U
%vn rLt$
fE7[Sk
public static void log(int sMsg) GT2;o
{ /zPN9 db
System.err.println(sMsg); f`H}Y!W(
} !P#lTyz
} ${mHbqN
$wC]S4C
wGAN"K:e
/* .(nq"&u-*
**TestMethod.java ~99Ta]U
*/ fs7JA=?:
package NetFox; >.QD:_@:
q4lL7@_
jbfMTb4
public class TestMethod { :^! wQ""
rzY7f: '
Q]7r?nEEhW
public TestMethod() 4ILCvM
{ ///xx/weblogic60b2_win.exe p}O@%*p.
try{ sR'rY[^/|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I6h{S}2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); - C8h$P
SiteFileFetch fileFetch = new SiteFileFetch(bean); (F~eknJ
fileFetch.start(); T?NwSxGo
} prhFA3 rW.
catch(Exception e){e.printStackTrace ();} |L<oKMZY
a!xKS8-S==
# 1I<qK
} &+JV\
bWG}>{fj
*>zr'Tt,W
public static void main(String[] args) O. @_2
{ Vg&`f
new TestMethod(); +X"TiA7{j
} 6e/2X<O
} ~@MIG
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