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)); s1E 0atT
} $E&T6=Wn
for(int i=0;i<nEndPos.length-1;i++) 0%Le*C'yk
{ c~4Cpy^
nEndPos = nStartPos[i+1]; ZY8w1:'
} tkH]_cH'w
nEndPos[nEndPos.length-1] = nFileLength; g^Hf^%3xP
} qTK(sW
} %W8iC%~
o">~ObR
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//启动子线程 ?HRS*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "-djA,`
for(int i=0;i<nStartPos.length;i++) Pro?xY$E)
{ <5D4h!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Xy%||\P{)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {Ef.wlZ
nStartPos,nEndPos,i); ii_kgqT^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }LCm_av
fileSplitterFetch.start(); 6}m`_d?
} =^GPQ_"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z\oTuW*B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =}%#j0a4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "9r$*\wOf
nEndPos = " + nFileLength); nShXY6bA
// fileSplitterFetch[nPos.length-1].start(); pbEWnx_
g<(!>:h
0VcHz$ 6
//等待子线程结束 l;KrFJ6
//int count = 0; }A+ncabm
//是否结束while循环 "T_9_6tH
boolean breakWhile = false; a7c`[
/='0W3+o*L
U+*l!"O,
while(!bStop) VsJ+-IHm
{ 1Xo0(*O
write_nPos(); (D%vN&F
Utility.sleep(500); kmc_%Wm}
breakWhile = true; ~h_ _Y>
u.|%@
\wD/TLS}
for(int i=0;i<nStartPos.length;i++) CV\^gTPmx
{ EYn?YiVFU
if(!fileSplitterFetch.bDownOver) w$/lq~zU
{ %-yzU/`JF
breakWhile = false; ; ?f+
break; o S=!6h
} 4VZI]3K,
} ,+ G
if(breakWhile) Nd]F 33|X
break; CDM6o!ur3
_\KFMe=PV
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//count++; COsmVQ.
//if(count>4) d_d&su E
// siteStop(); =TDKU
} }< H>9iJ:
r) x
bwzx_F/
System.err.println("文件下载结束！"); &muBSQ-
} ':fp|m)M
catch(Exception e){e.printStackTrace ();} 3nG.ah
} +Ps.HW#NY
WI4<2u;
O_8 SlW0e
//获得文件长度 'o6}g p)
public long getFileSize() ",3v%$>
{ I{OizBom
int nFileLength = -1; beBG40
try{ aaig1#a@1b
URL url = new URL(siteInfoBean.getSSiteURL()); u0Wt"d-=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <HoCt8>U
httpConnection.setRequestProperty("User-Agent","NetFox"); l<w7 \a6
F<k+>e
TG}owG]]
int responseCode=httpConnection.getResponseCode(); y62f{ks_/
if(responseCode>=400) sJ|pR=g)!
{ n!4\w>h
processErrorCode(responseCode); yf9"Rc~+
return -2; //-2 represent access is error ^T!Zz"/:
} ,_u7@Ix
I8?
Q__CW5&'u
String sHeader; {ogBoDS
gMI%!Y
}yK7LooM
for(int i=1;;i++) x6`mv8~9Db
{ HP.=6bJWi
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R>O_2`c
//Utility.log(in.readLine()); H[u9C:}9b
sHeader=httpConnection.getHeaderFieldKey(i); c'i5,\#X
if(sHeader!=null) gSwV:hm
{ fgd2jr3T
if(sHeader.equals("Content-Length")) x|a&wC2,{
{ VkFh(Br<{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4%J0e'iN
break; ot<d FvD
} p[JIH~nb
} AOZ C D{
else DLrV{8%W
break; E xhih^[_
} >`0U2K
} \W.CHSD
catch(IOException e){e.printStackTrace ();} zuLW'a6F-
catch(Exception e){e.printStackTrace ();} K khuPBd2
rNq*z,
?Z 2,?G
Utility.log(nFileLength); iSCkV2
`-uE(qp
^wolY0p
return nFileLength; S/XU4i:aV
} !G-+O#W`
@}Hu)HO
;stuTj@vH
//保存下载信息（文件指针位置） Ab ,^y
private void write_nPos() nZbI}kcm
{ oIE 1j?
try{ :EV.nD7
output = new DataOutputStream(new FileOutputStream(tmpFile)); $XhMI;h
output.writeInt(nStartPos.length); 8X,6U_>#a
for(int i=0;i<nStartPos.length;i++) ~pRgTXbz
{ $(9QnH1KY
// output.writeLong(nPos); .2fvRN92
output.writeLong(fileSplitterFetch.nStartPos); 7<xnE]jdq
output.writeLong(fileSplitterFetch.nEndPos); }qiZ%cT.G
} %XGm\p
output.close(); 5)RZJrN]
} 309 pl
catch(IOException e){e.printStackTrace ();} O6hzOyNX@
catch(Exception e){e.printStackTrace ();} /xk7Z q
} pJ] Ix *M
0(7 IsG=t
_p*9LsN$L
//读取保存的下载信息（文件指针位置） I1fpX |
private void read_nPos() j+_fHADq
{ BX?DI-o^h
try{ _iJ~O1qx,w
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8z1z<\
int nCount = input.readInt(); j9NF|
nStartPos = new long[nCount]; b)I-do+
nEndPos = new long[nCount]; 5*$yY-A
for(int i=0;i<nStartPos.length;i++) O=2|'L'h!
{ k4ti#3W5eG
nStartPos = input.readLong(); Bz ;r<Kn
nEndPos = input.readLong(); vUpAW[[
} ^!1!l-
input.close(); ">bhxXeiN
} ZIx-mC5
catch(IOException e){e.printStackTrace ();} P4[kW}R
catch(Exception e){e.printStackTrace ();} >$ZG=&
} oN1D&*
l ;:IL\*1I
}Z"iW/?"
private void processErrorCode(int nErrorCode) -$Z1X_~;)<
{ !rUP&DA
System.err.println("Error Code : " + nErrorCode); 6YM X7G]
} iqDyE*a
}Ja-0v)Wf
4`,(*igEv
//停止文件下载 @)U.Dbm
public void siteStop() U>PZ3
{ kG>jb!e@(
bStop = true; ;MS.ag#
for(int i=0;i<nStartPos.length;i++) a#j,0FKv
fileSplitterFetch.splitterStop(); IIR+qJ__|
kZw"a*6
Cb;6yE)!Z
} AY/.vyS
} ;R*-cm
//负责部分文件的抓取 jaoZ}}V_$
**FileSplitterFetch.java [Fr](&Tx
*/ /w?e(v<
package NetFox; KOy{?
lMY\8eobcB
'3>;8(sl
import java.io.*; XKjrS 9:
import java.net.*; Ljy797{f
K{P-+(
[9">}l
public class FileSplitterFetch extends Thread { LIID(s!bX
~71U s
;JkSZs3
String sURL; //File URL yzS^8,
long nStartPos; //File Snippet Start Position =d{6=2Pt
long nEndPos; //File Snippet End Position 4zMvHe
int nThreadID; //Thread's ID [bh?p+V
boolean bDownOver = false; //Downing is over 40kAGs>_
boolean bStop = false; //Stop identical i6if\B
FileAccessI fileAccessI = null; //File Access interface sq'm)g
kOQ)QX
I0}.!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ukR0E4p
{ XJ<"S p
this.sURL = sURL; \L*%?~
this.nStartPos = nStart; _w\9 \<%
this.nEndPos = nEnd; 6(8F4[D
nThreadID = id; SxRJ{m~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j[r}!;O
} -$Fj-pO\
J8:s=#5
C7%R2>}?f
public void run() HgQjw!
{ !eyLh&]5
while(nStartPos < nEndPos && !bStop) ;73S;IPR
{ 2)=whnFS
eGEwXza 4
JqzoF}WH
try{ rRe5Q
URL url = new URL(sURL); f-F=!^.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +fVvH
httpConnection.setRequestProperty("User-Agent","NetFox"); 1bV G%N
String sProperty = "bytes="+nStartPos+"-"; D:@W*,
httpConnection.setRequestProperty("RANGE",sProperty); #kW=|8X
Utility.log(sProperty); +M=h+3hw](
{>ba7-Cy+y
{"wF;*U.V
InputStream input = httpConnection.getInputStream(); ZG=]b%
//logResponseHead(httpConnection); <X8Urum
E22o-nI?1
:xsZz$
byte[] b = new byte[1024]; `PUqz&
int nRead; i-CJ{l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V(&L
{ *u$aItx
nStartPos += fileAccessI.write(b,0,nRead); Dmh$@Uu#F
//if(nThreadID == 1) 1mmL`M1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -gs I:-Xo
} o-8{C0>:
gNZwD6GMe?
3WwS+6R
Utility.log("Thread " + nThreadID + " is over!"); Dge#e
bDownOver = true; >6C\T@{lJ
//nPos = fileAccessI.write (b,0,nRead); 5=TgOS]R
} r8m}B#W7
catch(Exception e){e.printStackTrace ();} a OmG,+o
} t1Ts!Q2
} d'_q9uf'
f+:iz'b#U
$J6 .0O
//打印回应的头信息 pz^S3fy
public void logResponseHead(HttpURLConnection con) 1clzDwW
{ \n_7+[=E
for(int i=1;;i++) ='"Yj
{ L0![SE>
String header=con.getHeaderFieldKey(i); [Hx}#Kds
if(header!=null) !RKuEg4hQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Wet0qt]
Utility.log(header+" : "+con.getHeaderField(header)); )?jFz'<r
else 2*g2UP
break; =Z+^n ?"
} 2O kID WcM
} !~E/Rp
IOFXkpKR
]xvA2!)Q
public void splitterStop() I$"Z\c8;
{ .F ?ww}2p]
bStop = true; qJ;~ANwt
} XIIq0I
?A@y4<8R|
q[Ai^79
} aqSOC(jU
oRbWqN`F.
g]f<k2
/* 29:2Xu i
**FileAccess.java sPK]:iC
*//文件访问(定位，写) 1sXCu|\q
package NetFox; U4d7-&U
import java.io.*; dC6>&@ VX
C@-Hm
WoXAOj%iW
public class FileAccessI implements Serializable{ +Ug &
rai'x/Ut}+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qK'mF#n0#
RandomAccessFile oSavedFile; s`x2Go
long nPos; e,sS.
#.Dl1L/
k)knyEUi
public FileAccessI() throws IOException t3$cX_
{ 4<s;xSCL
this("",0); \gP?uJ
} +vZYuEq_
4b}p[9k
xiW}P% bf
public FileAccessI(String sName,long nPos) throws IOException wQ(DX!
{ Cx;it/8+
oSavedFile = new RandomAccessFile(sName,"rw"); A6szTX#0
this.nPos = nPos; }P2*MrkcHB
oSavedFile.seek(nPos); 0-p^oA
} Ow-ejo
lz=DGm
pKLcg"{[F
public synchronized int write(byte[] b,int nStart,int nLen) W<<G 'Km
{ ,q*|R O
int n = -1; \WE/#To
try{ 0faf4LzU!
oSavedFile.write(b,nStart,nLen); NL.3qx
n = nLen; ok--Jyhv#
} I6WHC*
catch(IOException e) ;FlDRDZ%
{ @IL@|Srs8
e.printStackTrace (); y6am(ugE
} Q8HNST($?
0^{Tq0Ri[
YEV;GFI1
return n; 86%k2~L
} q!&:y7O8
N_D=j6B
}*XF- U
} mTH[*Y,
(l][_6Q
.NdsKhg b
/* e`+
**SiteInfoBean.java 6 w!qZ4$
*/ ="T}mc
package NetFox; -)J*(7F(6^
tDAX pi(
`LFT"qnp
public class SiteInfoBean { a\-5tYo`u
PM*lnd#J
R?:K\
private String sSiteURL; //Site's URL V,ZRX}O
private String sFilePath; //Saved File's Path heF'7ezv#
private String sFileName; //Saved File's Name -0(+a$P7e
private int nSplitter; //Count of Splited Downloading File 2;:]Q.g
(QFZM"G
Z+R-}<
public SiteInfoBean() #d8]cm=
{//nSplitter的缺省值为5 >CCy2W^W
//default value of nSplitter is 5 /_<_X 7
this("","","",5); k5&}bj-
} #5;4O{
gd3MP^O1
/pe.?Zd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &}gH!5L m
{ fk^DkV^<
sSiteURL= sURL; 3Mh_&%!O
sFilePath = sPath; o)\EfPT
sFileName = sName; [Qkj}
this.nSplitter = nSpiltter; Pd:tRY+t/
CNiJuj`
3rh t5n2-
} 1b=\l/2
:@~3wD[y
_uh@fRyh
public String getSSiteURL() Qm3RXO
{ W*c^(W
return sSiteURL; 1%.CtTi
} ~O;?;@
%|}7YH41
l5e`m^GK
public void setSSiteURL(String value) IxG0TJ_
{ Qe[ai?iJkt
sSiteURL = value; k:s86q
} n-9X<t|*?a
DKQQZ`PF
c1%ki%J#
public String getSFilePath() <Dnv=)Rq
{ G* mLb1
return sFilePath; o,1Fzdh6(
} uN9.U _
arPqVMVr
:fG9p`
public void setSFilePath(String value) 2\}6b4
{ .dBW{|gN
sFilePath = value; wW/wvC-
} BGB.SN#q+
9&c *%mm
>GDN~'}^oz
public String getSFileName() LrfyH"#!:
{ QZ-6aq\sgp
return sFileName; Rm.9`<Y
} xI=[=;L
#5kg3OO
5o~AUo{
public void setSFileName(String value) ``?Z97rH
{ l&Fx< W
sFileName = value; ~i@Z4tj7
} (P:.@P~
Jxb+NPUB
~f2-%~
public int getNSplitter() YsjTC$Tx,
{ 1K$8F ~%Z
return nSplitter; 47/YDy%
} `WU"*HqW
LTY(6we-
S1$&
public void setNSplitter(int nCount) V,9UOC,Gn
{ BI)$aR
nSplitter = nCount; ErMA$UkJ
} rUF= uO(
} 8>^O]5Wo`X
_Ai\XS Am
_1Iw"K49Qx
/* nIP*yb}5
**Utility.java Z"<tEOs/En
*/ EEp,Z`
package NetFox; ~_L_un.R
G5x%:,n
b!|c:mE9|
public class Utility { [.iz<Yh
oxm3R8S
hz+x)M`Y
public Utility() OGO4~Up
{ $5l=&
T%:W6fH7
~4tu*\P
} j.rJfbE|X
#$>m`r
//线程睡眠 F0FF:><
public static void sleep(int nSecond) a)8M'f_z
{ hbdM}"&]
try{ 0~XZ
Thread.sleep(nSecond); SfwAMNCe
} V5LzUg]
catch(Exception e) wg,w;Gle
{ <[GkhPfZ
e.printStackTrace (); -i?-Xj#%
} P\H$*6v(
} VSt)~
fL&bN[XA"$
//日志 J4ltHk.|
public static void log(String sMsg) |P]>[}mD
{ viY&D
System.err.println(sMsg); MkG*6A
} D@>^_cTO24
`=3:*.T*
4jl-?
public static void log(int sMsg) `H6kC$^Ofx
{ Lm}:`
System.err.println(sMsg); 3"hPplE
} *7o(
} t/aT
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x, ^j=n
/* }A%Sx!7~
**TestMethod.java *G#W],~0
*/ 3Ga!)
package NetFox; y\&`A:^[ A
u>.qhtm[
.qCD(XZ+
public class TestMethod { /u8m|S<
>{^&;$G+*
RscU=oaKi
public TestMethod() 7x^P74
{ ///xx/weblogic60b2_win.exe um[nz
try{ Xo>P?^c4?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #yv_Eb02
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); AVA hS}*t
SiteFileFetch fileFetch = new SiteFileFetch(bean); tQ:)j^\
fileFetch.start(); Ln})\ UDK)
} xCMcS~ 3/
catch(Exception e){e.printStackTrace ();} @4D$Xl
t .&YD x
y#Ao6Od6
} L= fz:H
4cni_m]
8`*Wl;9u
public static void main(String[] args) )FkJ=P0
{ Og?]y ^y
new TestMethod(); /bj D*rj
} K -!YD}OF
} XOzd{
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