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)); b`yZ|j'ikd
} ^-mRP\5
for(int i=0;i<nEndPos.length-1;i++) sDr/k`>
{ SG}V[Glk
nEndPos = nStartPos[i+1]; Gb[`R}^dq
} 6qN~/TnHZ
nEndPos[nEndPos.length-1] = nFileLength; Spo?i.#
} :j|IP)-f
} 8l}1c=A}Vi
dzK{ Z
w-Nhs6
//启动子线程 Ol"3a|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MuoF FvAA
for(int i=0;i<nStartPos.length;i++) g%F"l2M
{ g(VNy@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (,^*So/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .=m,hu~
nStartPos,nEndPos,i); x!\ONF5$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oH0X<'
fileSplitterFetch.start(); 43?^7_l-
} _&K
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |KB0P@=a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :m86 hBE.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D=:04V}2+
nEndPos = " + nFileLength); !D!~^\
// fileSplitterFetch[nPos.length-1].start(); hA\K</h.
[."[pY
`V)Z)uN{0
//等待子线程结束 pa}*E
//int count = 0; Z_\C*^
//是否结束while循环 ?JL7=o X
boolean breakWhile = false; J=.`wZQkS
dz~coZ9
{t};-q!v$j
while(!bStop) qE'9QQ>:b
{ e8YMX&0%
write_nPos(); m<L;
Utility.sleep(500); rc+C?)S
breakWhile = true; =rdY @
1&fc1uYB4
3=-4%%[M@
for(int i=0;i<nStartPos.length;i++) G-9iowS/A
{ l5l>d62
if(!fileSplitterFetch.bDownOver) SIBoCs5
{ eEhr140
breakWhile = false; \!]Ua.e<
break; BBcV9CGU
} LZMYr
} hhoEb(BA
if(breakWhile) Y#!h9F
break; 4f(Kt,0
6}FO[
%OgS^_tu
//count++; Sq:0w
//if(count>4) $}")1|U,X
// siteStop(); As+t##gN
} kB5.(O
NrP0Ep%V
p ?wI9GY
System.err.println("文件下载结束！"); '`1CBU$
} 7d92Pe
catch(Exception e){e.printStackTrace ();} Qt]Q:9I[
} e#/E~r&
.9O$G2'oh
1-.~7yC
//获得文件长度 rJ KZ)N{
public long getFileSize() ?FfC
{ ]Qm]I1P
int nFileLength = -1; @ 49nJi
try{ VLBE'3Qg1
URL url = new URL(siteInfoBean.getSSiteURL()); 5k|9gICyd*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i-yy/y-N
httpConnection.setRequestProperty("User-Agent","NetFox"); @ P|LLG'
OFje+S
1Bxmm#
int responseCode=httpConnection.getResponseCode(); r! Ay:r
if(responseCode>=400) Y.^=]-n,
{ dMR3)CO
processErrorCode(responseCode); lI>SUsQFfm
return -2; //-2 represent access is error a<]B B$~
} g/13~UM\
I(=V}s2
QRLt9L
String sHeader; OT'[:|x ;
> xIJE2
ja=F7Usb
for(int i=1;;i++) 1~$);US
{ wcDRH)AW.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); m|OO,gR
//Utility.log(in.readLine()); h$L"8#
sHeader=httpConnection.getHeaderFieldKey(i); RmZ]" `
if(sHeader!=null) mDZ*E!B
{ tE7[Smzuf
if(sHeader.equals("Content-Length")) d\|!Hg,
{ \c^45<G2qA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V]90
break; v9T_&
} v@#b}N0n
} 3]?#he
else %Qk/_ R1
break; LkQX?2>]
} O9:U8$*
} Ali9pvE
catch(IOException e){e.printStackTrace ();} y!]CJigpZ
catch(Exception e){e.printStackTrace ();} ExRe:^yU\
?k(\ApVHj
epgPT'^
Utility.log(nFileLength); sUPz/Z.h
@?"h !fyu
KN-avu_Ix
return nFileLength; mS0udHod
} }`+B=h-dW
``E/m<r:$
}<'5 z qS
//保存下载信息（文件指针位置） F5o+kz$;
private void write_nPos() .KdyJ6o
{ } (!EuLL
try{ }%D^8>S
output = new DataOutputStream(new FileOutputStream(tmpFile)); LY+|[qka
output.writeInt(nStartPos.length); |*`Z*6n
for(int i=0;i<nStartPos.length;i++) 0?>dCu\
{ c&L"N!4z
// output.writeLong(nPos); d:yqj:
output.writeLong(fileSplitterFetch.nStartPos); ~Ch+5A;
output.writeLong(fileSplitterFetch.nEndPos); *}8t{ F@k
} W0}B'VS.I
output.close(); qoAj] ")
} c_elShK8#
catch(IOException e){e.printStackTrace ();} MTUn3;c/
catch(Exception e){e.printStackTrace ();} 6d+p7x
} Afk$?wkL
yV^s,P1
Uk\Id~xLV
//读取保存的下载信息（文件指针位置） H<1WbM:w
private void read_nPos() S6[v;{xJ
{ >|;aIa@9
try{ EAeqLtFqs
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |<O9Sb_
int nCount = input.readInt(); t:fFU1x
nStartPos = new long[nCount]; Q?X>E3=U
nEndPos = new long[nCount]; @$T 9Ll
for(int i=0;i<nStartPos.length;i++) *&f$K1p
{ `Qqk<o
nStartPos = input.readLong(); W2.qhY5
nEndPos = input.readLong(); vv=VRhwF
} `UBYp p
input.close(); gJM`[x`T
} (T2m"Yi:
catch(IOException e){e.printStackTrace ();} r7',3V
catch(Exception e){e.printStackTrace ();} /B}lO0]:
} ~9j%Hm0ht
?@V[#.
FHV-BuH5
private void processErrorCode(int nErrorCode) ^+g$iM[`f
{ jRL<JZ1N
System.err.println("Error Code : " + nErrorCode); J(6oL
} i'\T R|qd
u7=U^}#
[}&Sxgv
//停止文件下载 >KJ+-QuO&
public void siteStop() ) Yd?m0m*
{ r\/+Oa'
bStop = true; M|Rb&6O
for(int i=0;i<nStartPos.length;i++) F+u|HiYG
fileSplitterFetch.splitterStop(); ,{c?ymw?
>;[*!<pfK5
Phke`3tth
} @*sWu_-Y%
} 4t)/
//负责部分文件的抓取 AF%@VLf
**FileSplitterFetch.java GI&h`X5,e
*/ KVJ_E!i
package NetFox; f& CBU
8w.YYo8`
AA7C$;Z15~
import java.io.*; pa#IJ
import java.net.*; s;A@*Y;v
cb}[S:&|
r9dyA5oD
public class FileSplitterFetch extends Thread { ow]053:i
MNV% =G
Gh}*q|Lz
String sURL; //File URL ukUGvK
long nStartPos; //File Snippet Start Position v\{!THCSh
long nEndPos; //File Snippet End Position vuYSVI2=H
int nThreadID; //Thread's ID O6OP =K!t:
boolean bDownOver = false; //Downing is over F|!){=
boolean bStop = false; //Stop identical 1@-Ns
FileAccessI fileAccessI = null; //File Access interface <%"b9T`'
hq #?kN
\o^2y.q:>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j*vYBGD
{ #Q /Arq
this.sURL = sURL; sQ\8>[]
this.nStartPos = nStart; *Em,*!
this.nEndPos = nEnd; ,KFapz!
nThreadID = id; tdu$pC6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p}~qf
} % oo2/aF
pJtex^{!:
%ALwz[~]
public void run() 1{JV}O
{ ;&)-;l7M
while(nStartPos < nEndPos && !bStop) WILMH`
{ >=-(UA
hr)B[<9
aYSCw3C<
try{ t)}scf&^x
URL url = new URL(sURL); ;-qO'V:;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~W-PD
httpConnection.setRequestProperty("User-Agent","NetFox"); Uw7h=UQh
String sProperty = "bytes="+nStartPos+"-"; ~ (jKz}'~U
httpConnection.setRequestProperty("RANGE",sProperty); MpR2]k#n<
Utility.log(sProperty); HKUn`ng
b"{'T]"*j
N=7pK&NHSG
InputStream input = httpConnection.getInputStream(); k-^mIJo}
//logResponseHead(httpConnection); 5f 5f0|ok
:w^Ed%>y7
,JQp'e
byte[] b = new byte[1024]; ]'=)2 .}
int nRead; W}mn}gTQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >: g3k
{ R)m'lMi|
nStartPos += fileAccessI.write(b,0,nRead); \r+8qC[,
//if(nThreadID == 1) BNs@n"k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V6,H}k
} fd.^h*'mU
OL^l 3F
,]d/Q<
Utility.log("Thread " + nThreadID + " is over!"); @W"KVPd
bDownOver = true; z+n,uHs
//nPos = fileAccessI.write (b,0,nRead); Jh!I:;/
} )`(p9@,V
catch(Exception e){e.printStackTrace ();} #$8% w
} 2HsLc*9{4
} wG-HF'0L
Rx=>6,)'
YOmM=X+'H
//打印回应的头信息 >]vlkA(
public void logResponseHead(HttpURLConnection con) -^hWM}F
{ f@|A[>"V
for(int i=1;;i++) LoN< oj5
{ i\rDu^VQ
String header=con.getHeaderFieldKey(i); eEv@}1~
if(header!=null) =*c7i]@}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2$g6}A`r
Utility.log(header+" : "+con.getHeaderField(header)); %|q>pin2
else CU@Rob}s
break; %D%8^Zd_
} 1e{IC=
} MS 81sN\d
'6cWS'9"
BMG3|N^
public void splitterStop() YSic-6z0Ms
{ q=Sgk>NA
bStop = true; Rnr(g;2
} v50bdj9}k
qzKdQ&vO
i%#+\F.&
} :*Z4yx
%\dz m-d(C
--HZX
/* .*Ct bGw
**FileAccess.java zuJ@E=7
*//文件访问(定位，写) #~2%)
package NetFox; pz\ +U7
import java.io.*; D%OQ e#!
lm-dW'7&
[B#R94
public class FileAccessI implements Serializable{ Vt %bI0#
-.u]GeMy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8D3OOab
RandomAccessFile oSavedFile; 1PQ~jfGi
long nPos; .oYl-.E>&
Z<1FSk,[
Ui_8)z _
public FileAccessI() throws IOException eg\v0Y!rI
{ la0BiLzb]
this("",0); JQ8fdP A
} SPX$U5&
8<S~Z:JK
C*)3e*T*
public FileAccessI(String sName,long nPos) throws IOException LtWP0@JA
{ =n5zM._S-
oSavedFile = new RandomAccessFile(sName,"rw"); %p^wZtm
this.nPos = nPos; [YF>:ydk
oSavedFile.seek(nPos); +Mo9kC
} y~AVei&
0=@?ob7
@r/#-?W
public synchronized int write(byte[] b,int nStart,int nLen) Q]Y*K
{ 2,$8icM
int n = -1; L[oui,}_
try{ &zl|87M
oSavedFile.write(b,nStart,nLen); kO.%9wFbz
n = nLen; >Wm`v.-
} 8n#HFJ~
catch(IOException e) @Lpq~ 1eZB
{ aktU$Wbwl
e.printStackTrace (); |%F=po>w
} rn/ /%
<r.)hT"0
bR*-Ht+wd
return n; KyVQh8
} 8##-EN;ag
#a/5SZP Z\
9oRy)_5Z(=
} 7`-Zuf
V]|^&A_c
Q8:Has
/* !o5 W
**SiteInfoBean.java ^W`<gR
*/ 9_q#W'/X
package NetFox; Jj>?GAir
0[RL>;D:
*rM^;4Zt
public class SiteInfoBean { $*^kY;
r54&XE]O
09X01X[
private String sSiteURL; //Site's URL hEA<o67
private String sFilePath; //Saved File's Path :By?O"LQ
private String sFileName; //Saved File's Name R+2+-j4
private int nSplitter; //Count of Splited Downloading File RJL2J]*S
X\]L=>]C
ZOft.P O
public SiteInfoBean() $h2){*5E{
{//nSplitter的缺省值为5 j>*R]mr6
//default value of nSplitter is 5 zcel|oz)
this("","","",5); u8gS<\
} <LmIK
-l`f)0{
wm]^3qI2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &Ts-a$Z7?S
{ zV:pQRbt.
sSiteURL= sURL; W4[V}s5u
sFilePath = sPath; (EK"V';
sFileName = sName; u1t%(_h
this.nSplitter = nSpiltter; Ae69>bkE0
=g/{%;
SfgU`eF%B
} mu?Eco`~
7s"< 'cx_F
3BB%Z6F
public String getSSiteURL() A'G66ei
{ ktj]:rCkF
return sSiteURL; KC(xb5x Y
} U Z.=aQ}M
V2$h8\a
b'J'F;zh>
public void setSSiteURL(String value) )jkXSTZ
{ A/s>PhxV
sSiteURL = value; Ul2R'"FB
} AgV G`q
R&|mdY8
Vy*:ne
public String getSFilePath() ~.A)bp
{ Mr?Xp(.}G
return sFilePath; ox:[f9.5
} GDu~d<RH
5QPM t^
[F*.\
public void setSFilePath(String value) vz^<YZMu
{ *H?!;u=8
sFilePath = value; bx]N>k J
} \2ZPj)&-E
bHg,1y)UC
COTp
public String getSFileName() PZ{Dv'C
{ FDVcow*]n
return sFileName; w=^`w:5X
} 6)vSG7Ise
9:`(Q3Ei
U f|> (C
public void setSFileName(String value) TJ:]SB
{ .A-]_98Z
sFileName = value; ]Ar\c["
} pGf@z:^{*-
v2H#=E4cZ#
uiJS8(Cb
public int getNSplitter() OCZ[D{i9@
{ ZO4*sIw%
return nSplitter; %^1cyk
} K_2|_MLlZ
E<C&Cjz:H
_U{zMVr
public void setNSplitter(int nCount) >.'<J]
{ L0&RvI#
nSplitter = nCount; 2gzou|Y
} ]J:1P`k.
} }~"hC3w
ZTU&,1Y;
~(pmLZ<GW}
/* 'v\L @"
**Utility.java "TUe%o
*/ :$_6SQ<?
package NetFox; >m#e:[N
j'aHF#_
HAv{R!*
public class Utility { zGc: @z
)u/H>;L P
OM|Fwr$
public Utility() 4<cz--g
{ Q}!mx7b0]
#7ov#_2Jd
^{xeij/
} c-g)eV|)S
(`6T&>(4
//线程睡眠 NTS#sgP
public static void sleep(int nSecond) "Vr[4&`
{ p/2jh&
try{ &f7fK|}
Thread.sleep(nSecond); "dROb}szn
} @^;j)%F}
catch(Exception e) w|CZ7|6
{ RGn!{=
e.printStackTrace (); W`"uu.~f
} "wlt> SU
} I+!:K|^
Y!WG)u5
//日志 P7 PB t
public static void log(String sMsg) ?-tVSRKQ
{ R(-<BtM!-
System.err.println(sMsg); Ja SI^go
} N`E-+9L)
h'$QC )P
ifo7%XPcg
public static void log(int sMsg) RJy=pNztm
{ ]r3Kg12Mi
System.err.println(sMsg); :5/Uh/sX
} >6oOZbUY0
} (;%|-{7e-
,+g&o^T
Dw7vv]+ S
/* EwS!]h?
**TestMethod.java `]LSbS
*/ ork=`};
package NetFox; XyMG.r-,
[]0mX70N
RNPbH.
public class TestMethod { 7~ztwL
A~Xq,BxCV
15$4&=O
public TestMethod() T6pLoaKu
{ ///xx/weblogic60b2_win.exe 0aoHKeP
try{ v|ox!0:#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); JbO ~n )%x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }tPk@$
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]I/Vbs
fileFetch.start(); pG^}Xf2a
} |3+m%;X
catch(Exception e){e.printStackTrace ();} kkvtB<<Y
r-kMLw/)
{B*W\[ns
} ]O{u tm
okq[ o90
r}u%#G+K,
public static void main(String[] args) hF3&i=;.
{ q{die[J
new TestMethod(); x90jw$\%7
} 5cK@WE:
} #a| L3zR5v
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