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)); @ !su7
} 8b'@_s!_
for(int i=0;i<nEndPos.length-1;i++) !38KHq^|&
{ vO2WZ7E!
nEndPos = nStartPos[i+1]; H%Gz"
} Qf^c}!I
nEndPos[nEndPos.length-1] = nFileLength; ;&6 {c
} yZNG>1N
} BZQ}c<Nl
(J5}1Q<K
,3_Sf?
//启动子线程 E5rV}>(Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fV>d_6Lf}
for(int i=0;i<nStartPos.length;i++) oMg-.!6
{ Gl'G;F$Y-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W/BPf{U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;]grbqXVE
nStartPos,nEndPos,i); 41Q5%2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $L0sBW&
fileSplitterFetch.start(); I m I$~q'
} q{9 \hEeb
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $?W2'Xm!V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q}L`8(a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5xdeuBEY8
nEndPos = " + nFileLength); ?lD)J?j
// fileSplitterFetch[nPos.length-1].start(); ;&CLb`<y
g?"QahHG
7!cLTq
//等待子线程结束 \_,p@r]Q
//int count = 0; MwRLv,&"
//是否结束while循环 xkRMg2X.>9
boolean breakWhile = false; kqih`E9P7B
Skci;4T(
1}la)lC
while(!bStop) k^;n$r"i5
{ qA)YYg/G
write_nPos(); s$pXn&:
Utility.sleep(500); 8&8!(\xv
breakWhile = true; <9X@\uvU.<
yR|2><A
uFSU|SDd.
for(int i=0;i<nStartPos.length;i++) 5GScqY,aB
{ i!}k5k*Z
if(!fileSplitterFetch.bDownOver) n?cC]k;P~
{ $Okmurnn
breakWhile = false; .5a>!B.I
break; _2G _Io
} LXX('d
} HJ]v-
if(breakWhile) >D!R)W`
break; .+(V</
F\+AA
FhY#3-jH
//count++; R&(OWF;~,
//if(count>4) WcqR; Nm
// siteStop(); EQlb:;j
} \54B
&Iy5@8
9pnOAM}
System.err.println("文件下载结束！"); %Ve@DF8G
} nu+K N,3R"
catch(Exception e){e.printStackTrace ();} /xJD/"Y3&
} w*XM*yJHU
4Pc-A
wJ2cAX;"
//获得文件长度 nE8z1hBUq
public long getFileSize() "|Q.{(|kO1
{ E<+ G5j
int nFileLength = -1; ~{lb`M^]h
try{ X<8|uP4
URL url = new URL(siteInfoBean.getSSiteURL()); I ==)a6^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'qT;Eht5
httpConnection.setRequestProperty("User-Agent","NetFox"); 5&Yt=)c\
zs]ubJC@
>&;J/ME
int responseCode=httpConnection.getResponseCode(); ]'Eg2(wy
if(responseCode>=400) zGU MH7 M
{ ?:9y !Q=
processErrorCode(responseCode); iT==aJ=~/&
return -2; //-2 represent access is error V WZpEi
} 2o<*rH
I"czo9Yspd
W8^A{l4
String sHeader; &T,,fz$
I1>f2/$z*
G 0pq'7B
for(int i=1;;i++) :Y/aT[
{ 3>VL>;75[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GYQ:G=
//Utility.log(in.readLine()); sG#Os
sHeader=httpConnection.getHeaderFieldKey(i); ?1\I/'E9
if(sHeader!=null) 3v_j*wy
{ /Q@4HV
if(sHeader.equals("Content-Length")) eG(YORkR
{ /~'C!so[v
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r~T!$Tb
break; LAk .f
} "W6cQsi
} ]'xci"qV`
else YQ:$m5ai
break; _Kaqx"D
} W[J2>`k9
} wwdmz;0S
catch(IOException e){e.printStackTrace ();} N~/X.D4e#
catch(Exception e){e.printStackTrace ();} l=XZBe*[g'
A<c<!N
Xxh^4vKjX
Utility.log(nFileLength); 2H$](k?
=Ks&m4
UNb7WN
return nFileLength; TU_'1
} 0cB]:*W
.?NfV%vv
vT{(7m!Ra
//保存下载信息（文件指针位置） p9i7<X2&
private void write_nPos() no-";{c
{ 6 DQOar>d
try{ Cu%BU}(
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4qDO(YWf
output.writeInt(nStartPos.length); 4`l$0m@>
for(int i=0;i<nStartPos.length;i++) ~\-=q^/!
{ b~fl,(sZp
// output.writeLong(nPos); [F*yh9%\
output.writeLong(fileSplitterFetch.nStartPos); ^n~Kr1}nj
output.writeLong(fileSplitterFetch.nEndPos); *<cRQfA1
} BKTTta1mY
output.close(); xS@jV6E~
} (^B1Kt!<
catch(IOException e){e.printStackTrace ();} prS%lg>
catch(Exception e){e.printStackTrace ();} /Hk})o_
} Y{j~;G@Wl
`/m]K~~
g5 *E\T%8
//读取保存的下载信息（文件指针位置） dY$nw
private void read_nPos() HkRvcX 5
{ M)K!!Jqh
try{ D#'CRJh;7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $9\8?gS
int nCount = input.readInt(); FDuA5At
nStartPos = new long[nCount]; ][Tw^r&
nEndPos = new long[nCount]; {nSgiqd"28
for(int i=0;i<nStartPos.length;i++) Bkq4V$D_
{ oNXYBeu+
nStartPos = input.readLong(); $G0e1)D
nEndPos = input.readLong(); %9zpPrWF
} DmgDhNXKq
input.close(); lv]U)p
} $Xo_8SX,
catch(IOException e){e.printStackTrace ();} FP{=b/
catch(Exception e){e.printStackTrace ();} MbYgGE,LA
} AiR#:r
4mW$+lzn
81#x/&E]
private void processErrorCode(int nErrorCode) ,O.iOT0=;
{ >Q=e9L=
System.err.println("Error Code : " + nErrorCode); u=@zYA(
} ]2"UR_x
$U ._4
B_Gcz5
//停止文件下载 fGj66rMGw
public void siteStop() Se[=$W
{ [%LGiCU]
bStop = true; `@\FpV[|P
for(int i=0;i<nStartPos.length;i++) ?-&k?I
fileSplitterFetch.splitterStop(); ?7CdJgJp
2vUcSKG7
D3g5#.$,}>
} G@D8[
} (oiQ5s^f
//负责部分文件的抓取 '#A_KHD
**FileSplitterFetch.java 9BOn8p;yz
*/ p79QEIbk=
package NetFox; (@T{ [\
5R.jhYAj
#%GBopv
import java.io.*; kQ\l7xd
import java.net.*; yAGQD[ih
=?Co<972Z
Q!-"5PX
public class FileSplitterFetch extends Thread { yWc%z6dXC
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:k_)Bh?+
String sURL; //File URL #Z]Cq0=
long nStartPos; //File Snippet Start Position h3>u[cX%
long nEndPos; //File Snippet End Position b't6ekkN
int nThreadID; //Thread's ID :L:] 3L
boolean bDownOver = false; //Downing is over \A!Iln
boolean bStop = false; //Stop identical NmpNme
FileAccessI fileAccessI = null; //File Access interface WB (?6"
uUBUUr
WM$Z?CN%KB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'YN:cr,V
{ fUq}dAs*K
this.sURL = sURL; RigS1A\2l
this.nStartPos = nStart; h+q#|N
this.nEndPos = nEnd; (u8OTq@
nThreadID = id; Wvd-be
fileAccessI = new FileAccessI(sName,nStartPos);//定位 nF3Sfw,
} hn6'$P
~tNk\Kkv
~P!=fU)
public void run() 9-A@2&J1
{ o}wRgG
while(nStartPos < nEndPos && !bStop) [D?xd/G
{ %PR,TWe
e7Gb7c~
9*"K+t:
try{ Q.8^F
URL url = new URL(sURL); mT j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qncZpXw^
httpConnection.setRequestProperty("User-Agent","NetFox"); us8ce+
String sProperty = "bytes="+nStartPos+"-"; H-WNu+
httpConnection.setRequestProperty("RANGE",sProperty); l)KN5V
Utility.log(sProperty); dj,lbUL
3uvl'1(%J
rP6k}
InputStream input = httpConnection.getInputStream(); f~jdN~
//logResponseHead(httpConnection); s!Id55R]
3!?QQT,!)
x)q$.u+
byte[] b = new byte[1024]; ~Wm'~y>
int nRead; g*9&3ov
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8z&/{:Z@pH
{ Br$/hn=
nStartPos += fileAccessI.write(b,0,nRead); '/ueY#eG
//if(nThreadID == 1) +~ S7]AZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |CS&H2!s
} zZ<~yi3A9
*D7oHwDU
D*HK[_5
Utility.log("Thread " + nThreadID + " is over!"); )B@&q.2B=
bDownOver = true; 2<2a3'pG
//nPos = fileAccessI.write (b,0,nRead); Np~qtR
} hL;??h,!_
catch(Exception e){e.printStackTrace ();} k[1[Y{n.
} zb9vUxN [
} k'[\r>T
hB:+_[=Kj.
K^I$05idi
//打印回应的头信息 )gR3S%Ju
public void logResponseHead(HttpURLConnection con) dt>!=<|k
{ Z%-uyT@a
for(int i=1;;i++) 6|Rj YX
{ w'5W L
String header=con.getHeaderFieldKey(i); ?GZ?HK|
if(header!=null) b DF_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Oo\~'I
Utility.log(header+" : "+con.getHeaderField(header)); giN(wPgYP
else LR17ilaa'
break; +hWeN&A
} xJvalb
} wz'in
B)-P#,}
R?*-ZI[>w
public void splitterStop() %#]/]B/4
{ ?H!X p
bStop = true; 6>EoU-YX}l
} :~,akX$
OBPiLCq
*41WZE
} 5bWy=Xk B
{\=NZ\
r2Q) Q
/* }M\G
**FileAccess.java wK%x|%R[
*//文件访问(定位，写) AWmJm)
package NetFox; A<g5:\3
import java.io.*; rHtX4;f+><
+d6Jrd*
lU3Xd_v O
public class FileAccessI implements Serializable{ D <Fl7QAb
o\yqf:V8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kZ 9n@($B
RandomAccessFile oSavedFile; SR\$fmo
long nPos; Fg^zz*e
[ **F
%{P." ki
public FileAccessI() throws IOException -| t|w:&
{ @]{:juD~
this("",0); tbi(e49S
} gem+$TFq
n<sA?T
h1?.x
public FileAccessI(String sName,long nPos) throws IOException -IS?8\Q<
{ TGPHjSZ1
oSavedFile = new RandomAccessFile(sName,"rw"); 7o M]qLF
this.nPos = nPos; EY!P"u;
oSavedFile.seek(nPos); $%J$
} Vg"Ze[dA
V P4ToYc
i>rsq[l
public synchronized int write(byte[] b,int nStart,int nLen) ; >>/}Jw\
{ P,Rqv)}X
int n = -1; mZ t:
try{ C;!h4l7L
oSavedFile.write(b,nStart,nLen); =}4lx^`oeT
n = nLen; l'Z `%}R
} mc5$-}1V,
catch(IOException e) @Cd}1OT)
{ kC6s_k
e.printStackTrace (); 27jZ~Bp$
} L`Q9-#Y
d`Em)3v
"LH*T
return n; Fqp~1>wi
} \A3yM{G~+
8uhB&qxB
WN?meZ/N/
} i(>v~T,(
Z$a4@W9o
z15QFVm
/* O0<GFL$)&
**SiteInfoBean.java QJ-?67_i
*/ !J@pox-t
package NetFox; `<l|XPv
,TxZ:f`"
uv dx>5]
public class SiteInfoBean { A&fh0E (t
c)o[3o7
]^\+B4
private String sSiteURL; //Site's URL $JXQn
private String sFilePath; //Saved File's Path mJ5LRpXN
private String sFileName; //Saved File's Name h?:Y\DlU'
private int nSplitter; //Count of Splited Downloading File pNzGpCk
7QkAr
,s1n!@9
public SiteInfoBean() ui6B
{//nSplitter的缺省值为5 r\66]u[
//default value of nSplitter is 5 ?|9$o/Q}
this("","","",5); /L"&'~
} ;42D+q=s
;w}5:3+
w]0jq U6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gBG.3\[
{ S\UM0G}v
sSiteURL= sURL; +nslS:(
sFilePath = sPath; I2=Kq{
sFileName = sName; R OQIw
this.nSplitter = nSpiltter; QcQ|,lA.HI
;EfMTI}6K
KPA5 X]
} MXhRnVz"W
B1Iq:5nmoS
{N,w5!cP
public String getSSiteURL() uy;3s=03^
{ D r$N{d
return sSiteURL; 5OUe|mS
} {\e wf_pFk
g)iSC?H
!f\6=Z?>3
public void setSSiteURL(String value) DEC,oX!bI1
{ yMa5?]J
sSiteURL = value; _?2xIo
} thDE 1h
~dwl7Qc
Q$9`QY*6"p
public String getSFilePath() b\\?aR |
{ vu.f B4
return sFilePath; Ic/<jFZXM
} JhDjY8?86
;mb 6i_
|E]YP~h
public void setSFilePath(String value) 7_/.a9$G
{ &[KFCn
sFilePath = value; -}juj;IVv
} GOwd=]e
S[" &8Fy
i9)y|
public String getSFileName() <s#}`R.#2
{ ;@d<*
return sFileName; ZdHWSfO)O
} 5y"yd6O]O5
MJXm7<(
ix&hsNzD
public void setSFileName(String value) ?I 1@:?Qi
{ }Gz"og*8
sFileName = value; 5J&n<M0G1
} TCF[iE{
uj/le0
ZcO!cR&*'J
public int getNSplitter() hoeTJ/;dm
{ <ZrZSt+<
return nSplitter; +V8yv-/{
} 3P6!j
"5jZS6A]
sinG $=
public void setNSplitter(int nCount) nhCB])u8l
{ IW1]H~1w
nSplitter = nCount; ,?#-1uIGL>
} +dh]k=6
} y_QxJ~6t
1=(i{D~
|$b4{
/* I( y Wct
**Utility.java l1wxs@](
*/ Il;'s
package NetFox; Z gU;=.
s/To|9D
FJL9x,%6
public class Utility { sfrh+o57
6y5arP*6e
{2:H`|x
public Utility() %r!#
{ H[Pb Wy:
puqH%m+u
>LU*F|F]B
} [bOy,^@4
>PGm}s_
//线程睡眠 |_=jXf\TL
public static void sleep(int nSecond) zPkg3H
{ !s)$_tG
try{ X}usyO'pW
Thread.sleep(nSecond); n`:l`n>N$
} "?9fL#8f*!
catch(Exception e) &&<^wtznO
{ !J6s^um
e.printStackTrace (); CWN=6(y
} Y+=@5+G
} (wY%$kW4
gCm?nb)
//日志 Xs`:XATb/
public static void log(String sMsg) ev guw*u
{ yauP j&^R
System.err.println(sMsg); 462ae` 6l
} *r%mqAx(
<s7{6n')
g<dCUIbcQ
public static void log(int sMsg) ~!nd'{{9
{ b{dzbmak
System.err.println(sMsg); OVh/t#On
} Uq+ _#{2(
} m5x>._7le
<NAR'{f
BA>0 +
/* Q)}\4&4
**TestMethod.java n[WeN NU
*/ 0F~9t!
package NetFox; :<v$vER,&
q9!#S
4*,q1yK
public class TestMethod { x> q3w# B
0Its;|
+8Px` v1L
public TestMethod() q7PRJX
{ ///xx/weblogic60b2_win.exe Z{CL!
try{ jI V? p
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zg j35
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z$V8<&q
SiteFileFetch fileFetch = new SiteFileFetch(bean); O``MUb b
fileFetch.start(); ?7p| F^
} i|O7nB@
catch(Exception e){e.printStackTrace ();} A_fU7'B
/uc/x+(_
w${=dW@K
} $^XPk#$m
!?>)[@2 k6
Zll^tF#
public static void main(String[] args) UKBMGzu2:
{ %Uk/P
new TestMethod(); .0-m=3mp2
} 3d<HIG^W}
} Xda<TX@-
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