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)); GQqw(2Ub}
} 1E$Z]5C9
for(int i=0;i<nEndPos.length-1;i++) /6{`6(p
{ qNHS 1
nEndPos = nStartPos[i+1]; N(Y9FD;H
} x+B~t4A
nEndPos[nEndPos.length-1] = nFileLength; N=D Ynz_~
} Tp`)cdcC[
} 37p0*%a":
qIjC-#a=m
m?<8 ':
//启动子线程 ?Z4&j'z<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p8s2#+/
for(int i=0;i<nStartPos.length;i++) 3+A 0O%0*
{ gZM{]GQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mk\U wv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |+6Z+-.Hg
nStartPos,nEndPos,i); dMGu9k~u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *(?YgV
fileSplitterFetch.start(); 7P/j\frW
} nWFp$tJ/R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1)_f9GR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^\N2 Iu>6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @mP@~
nEndPos = " + nFileLength); ,_NO[+5U
// fileSplitterFetch[nPos.length-1].start(); #*S/Sh?Q
RB/[(4
*XH?|SV
//等待子线程结束 |D]jdd@!a2
//int count = 0; 6FEtq,;0w
//是否结束while循环 7]e]Y>wZap
boolean breakWhile = false; pMt]wyKr
b@YSrjJ
hph 3kfR
while(!bStop) pvmm" f
{ z*yN*M6t
write_nPos(); bSz6O/A/
Utility.sleep(500); *\VQ%_wg
breakWhile = true; "6Dz~5
twgU ru
w-/bLg[L?$
for(int i=0;i<nStartPos.length;i++) 2gt08\
{ Yf{s0Z
if(!fileSplitterFetch.bDownOver) $Z{ fKr
{ CWBsiL f
breakWhile = false; *3"C"4S
break; D%^EG8i n.
} NmB0CbB
} >5^Z'!Z"
if(breakWhile) &OI=rvDmo
break; z[t$[Qg
-D!F|&$
Kq{s^G
//count++; W!tP sPM
//if(count>4) |{9"n<JW
// siteStop(); 9,y&?GLP
} f[|xp?ef
K03a@:
_^a.kF
System.err.println("文件下载结束！"); Nm,vE7M
} m7M*)N8
catch(Exception e){e.printStackTrace ();} 8l='Hl
} tAc;O[L
Q 5@~0
p~3CXmUc~
//获得文件长度 3tr?-l[N\
public long getFileSize() (Mtc&+n{
{ ~Zj?%4
int nFileLength = -1; 1]hMA\x
try{ aaaC8;.
URL url = new URL(siteInfoBean.getSSiteURL()); 2&tGJq-E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gpw(j0/Fs
httpConnection.setRequestProperty("User-Agent","NetFox"); 9l,Gd
l>qCT
q1?2 U<
int responseCode=httpConnection.getResponseCode(); {.!:T+'Xi\
if(responseCode>=400) .5dZaI)
{ ,Y`C7Px
processErrorCode(responseCode); ^2mXXAQf7^
return -2; //-2 represent access is error QGLm4 Wl9
} <|2_1[,sl
"V9!srIC
3i s.c)
String sHeader; }VFSF/\^
2}}~\C}o+
,#c-"xY
for(int i=1;;i++) 8"<!8Img
{ DG:=E/@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y!v$5wi
//Utility.log(in.readLine()); g:2/!tujL
sHeader=httpConnection.getHeaderFieldKey(i); Ft>ixn
if(sHeader!=null) G+%ZN
{ k"sL.}$
if(sHeader.equals("Content-Length")) Pu9.Uwx
{ _8S).*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W:) M}}&H
break; Ko%rB+d
} ?v")Z0 ~
} #); 6+v
else &pmJ:WO,h
break; *=sU+x&X
} u{3KV6MS
} u5,IH2BU
catch(IOException e){e.printStackTrace ();} O!j@8~='
catch(Exception e){e.printStackTrace ();} pixI&iQ
"^trHh8=
]Ny]Ox<
Utility.log(nFileLength); FcWu#}.p}
qkBnEPWZy
QWxQD'L'
return nFileLength; k[zf`x^
} Hv`Zc*
;J5oO$H+68
I+<;Dsp
//保存下载信息（文件指针位置） ##n\9ipD
private void write_nPos() Qy$QOtrv
{ Z7f~|}
try{ '{+hti,Lh
output = new DataOutputStream(new FileOutputStream(tmpFile)); +Rh'VZJs
output.writeInt(nStartPos.length); (&gCVf
for(int i=0;i<nStartPos.length;i++) %(e=Q^=
{ brVT
// output.writeLong(nPos); ]':C~-RV{
output.writeLong(fileSplitterFetch.nStartPos); jxoEOEA
output.writeLong(fileSplitterFetch.nEndPos); A9R}74e4g
} m0#hG x
output.close(); x[?_F
} eU12*(
catch(IOException e){e.printStackTrace ();} /J6CSk
catch(Exception e){e.printStackTrace ();} EP8LJzd"
} b,@:eVQ7
asJYGqdF
<T}#>xHs3
//读取保存的下载信息（文件指针位置） O@$hG8:
private void read_nPos() tT v@8f
{ \.{JS>!
try{ _AO0:&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); c49#aNR
int nCount = input.readInt(); [6Wr t8"
nStartPos = new long[nCount]; >:xnjEsi$/
nEndPos = new long[nCount]; cK258mY
for(int i=0;i<nStartPos.length;i++) IX>|bA;
{ kQb0pfYs
nStartPos = input.readLong(); s R~&S))
nEndPos = input.readLong(); ~ 52
} hh?'tb{
input.close(); =?2y <B
} lfKknp#B/O
catch(IOException e){e.printStackTrace ();} p<+]+,|\~:
catch(Exception e){e.printStackTrace ();} *dQRs6
} t.zSJ|T_&O
K1hw'AaQ
CVUDN2
private void processErrorCode(int nErrorCode) &p%,+|
{ mA."*)8VNg
System.err.println("Error Code : " + nErrorCode); CJC|%i3
} d}G?iX;c}
`SG70/
>hhd9
//停止文件下载 she`_'?5
public void siteStop() l?~ci ;lG
{ V.F 's(o
bStop = true; dOhV`8l
for(int i=0;i<nStartPos.length;i++) AVJk
fileSplitterFetch.splitterStop(); EvYw$j
y>OZ<!`
_c&*'IY[V
} )FP|}DCxQ
} G^R;~J*TDE
//负责部分文件的抓取 *Z]| Z4Q/`
**FileSplitterFetch.java izKk@{Md
*/ w(yU\ N
package NetFox; ,VZ&Gc
^AM_A>HnG
J.&q[
import java.io.*; OBl8kH(b>
import java.net.*; MJb = +L
{, |"Rpd
QA3l:D}u
public class FileSplitterFetch extends Thread { <Hp"ZCN
*"5a5.`%,
R*y[/Aw
String sURL; //File URL ^Pf&C0xXv
long nStartPos; //File Snippet Start Position zbR.Lb
long nEndPos; //File Snippet End Position 98]t"ny [
int nThreadID; //Thread's ID <Z;7=k
boolean bDownOver = false; //Downing is over G225Nz;Y*
boolean bStop = false; //Stop identical KH7]`CU
FileAccessI fileAccessI = null; //File Access interface |:?.-tq
<7rK
GlZ9k-ZRF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~Qsj)9
{ lEDHx[q
this.sURL = sURL; Lwcw%M]
this.nStartPos = nStart; Rf^cw}jU
this.nEndPos = nEnd; GW#kaqC1
nThreadID = id; U,M,E@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YUb,5Y0
} a(~YrA%~
s,v#lJ]d0W
d{hYT\7~1(
public void run() ]aRD6F:L
{ S=g-&lK
while(nStartPos < nEndPos && !bStop) 5%`Ul
{ *N r|G61
ZX;k*OrW
55DzBV
try{ aX%Zuyny
URL url = new URL(sURL); nnNg^<[k3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w'0M>2
httpConnection.setRequestProperty("User-Agent","NetFox"); UT~2}B9fc
String sProperty = "bytes="+nStartPos+"-"; ;5k|gW
httpConnection.setRequestProperty("RANGE",sProperty); (3h*sd5ly
Utility.log(sProperty); ?GarD3#A
xW9 s[X
])L'Rk#4
InputStream input = httpConnection.getInputStream(); |w2AB7EU
//logResponseHead(httpConnection); pCUOeQL(
a~7osRmp0
uq%3;#[0
byte[] b = new byte[1024]; ?v8k& q^q
int nRead; %m) h1/l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9u@h`
{ #6jwCEo=V
nStartPos += fileAccessI.write(b,0,nRead); BmFME0
//if(nThreadID == 1) kA;Tr4EA6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PL$F;d
} vx@p;1RU`
GKhwn&qCKb
)hW {>Y3x
Utility.log("Thread " + nThreadID + " is over!"); @%nUfG7TQ
bDownOver = true; +fQL~0tA
//nPos = fileAccessI.write (b,0,nRead); ^(JHRH~=h
} AdW2o|Uap
catch(Exception e){e.printStackTrace ();} /7@2Qc2
} r)]CZ])
} [0ffOTy
TDE1z>h+"
>Mz|e(6
//打印回应的头信息 _1> 4Q%
public void logResponseHead(HttpURLConnection con) 5b`xN!c
{ ONq/JW$?LV
for(int i=1;;i++) (+8xUc(w
{ )UZ0gfx
String header=con.getHeaderFieldKey(i); /)?P>!#;\
if(header!=null) r&3o~!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Fg\| e%
Utility.log(header+" : "+con.getHeaderField(header)); w1#jVcUQ
else KBRg95E~]l
break; HL}~W}!j
} E D^rWE_
} 5[2.5/
`vxrC&,As
XQJ^)d00h
public void splitterStop() j$8|ym^OX
{ @Du}
bStop = true; tP Efz+1N
} )cKtc
&<V_[Wh"
hRa(<ZK
} c`i=(D<
uWB:"&!^
B+e_Y\Bu
/* *Iwk47J ;a
**FileAccess.java ;IuK2iDt<
*//文件访问(定位，写) wvmg)4,
package NetFox; PWk?8dL-
import java.io.*; q_]
(OyY_`
&[ u6oAR
public class FileAccessI implements Serializable{ n;kciTD%wK
W-!Bl&jF[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,M@m4bx
RandomAccessFile oSavedFile; |pH* CCA
long nPos; s1Tl.p5
Wz-3?EQ
w38c
public FileAccessI() throws IOException `$V[;ld(mz
{ RZ|HwYG
this("",0); wyrI8UY
} ]]uzl0LH
Z6R: rq
{yHB2=nI
public FileAccessI(String sName,long nPos) throws IOException P~\a)Szy
{ &:DCtjK
oSavedFile = new RandomAccessFile(sName,"rw"); ,_Qe}qFU
this.nPos = nPos; sWsG,v_
oSavedFile.seek(nPos); tt7PEEf
} "$W|/vD+
XSp x''l
%jZp9}h
public synchronized int write(byte[] b,int nStart,int nLen) Db#W/8 a8k
{ 5 dfe@$
int n = -1; %oh`EGmVP
try{ Txt%nzIu
oSavedFile.write(b,nStart,nLen); bB;~,W&E1
n = nLen; N753
} M<A;IOpR+
catch(IOException e) *(d6Z#
{ 8tLT'2+H#
e.printStackTrace (); =mKfFeO.
} obAs<nk
HJfQ]p'nK2
qe5tcv}u
return n; .'^6QST
} @V* ju
ZDOF
p.rdSv(8'
} z^gQ\\,4
r~$}G-g
| V.S.'
/* %\}dbYS '
**SiteInfoBean.java &'5@azU
*/ }BI~am_
package NetFox; Gur8.A;Y
dGbU{#"3s
k9}Q7)@
public class SiteInfoBean { SY%A"bC
xSpMyXrQ
I.^X2
private String sSiteURL; //Site's URL k4qLB1&,
private String sFilePath; //Saved File's Path [x;(cISK1
private String sFileName; //Saved File's Name Rk($lW)
private int nSplitter; //Count of Splited Downloading File T}n N=Q4
^M`>YOU2+
n-b>m7O(
public SiteInfoBean() L6|Hgrj-u
{//nSplitter的缺省值为5 "/ tUA\=j
//default value of nSplitter is 5 $}qDV> qo
this("","","",5); = EQN-{#
} )KSisEL
On#;)35M
`Y\gSUhzS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W(;x\Nc7
{ xS=_yO9-
sSiteURL= sURL; O&`U5w
sFilePath = sPath; k2EHco0BG
sFileName = sName; ,>D ja59
this.nSplitter = nSpiltter; )Rjb/3*!
E]?)FH<oP
3jvx2
} ]i-P-9PA4
VZ\O9lD
R[x7QlA;
public String getSSiteURL() jCU=+b=
{ x&at^Fp
return sSiteURL; lVP9=
} >vUB%OLyP
FoE|Js
%tT"`%(+
public void setSSiteURL(String value) TQ; Z.)L
{ Rw{$L~\
sSiteURL = value; `_|aeoK_
} P+[QI U
b<[jaI0
3^{8_^I
public String getSFilePath() EJ1Bq>u7
{ j]rXoV>
return sFilePath; 2zz,(RA
} H5~1g6b@
ToV6lS"
js~tKUvg
public void setSFilePath(String value) Ve)ClH/DW
{ N? M
sFilePath = value; w#oGX
} %B@!
t5xb"F
NwguP
public String getSFileName() }i(qt&U;
{ BWWq4mdb{
return sFileName; YQ; cJ$
} k^z0Lo|)'
aSel* L
T'E] i!$
public void setSFileName(String value) Bp :~bHf
{ Z.quh;
sFileName = value; T=WNBqKo]
} WE0}$P:
~8TF*3[}[
:Zza)>l
public int getNSplitter() .;9jdGBf
{ zxkM'8JC
return nSplitter; X/l;s
} _g[-=y{Bb
-;$nb~y
{3LA%xO
public void setNSplitter(int nCount) +]c/&Xo!
{ ^5>s7SGB"
nSplitter = nCount; 9e!vA6Fx
} e&0K;yU
} @D)Z{=>{=5
L1sqU-gt
B@ {&<
/* !DPF7x(-{
**Utility.java 8'_ 0g[s
*/ 1]T|6N?
package NetFox; 3Hw[s0[$
e # 5BPI
YGp)Oy}:
public class Utility { {pWBwf>R C
}x:0os
dy2rkV.z
public Utility() JEhm1T
{ !;v.>.lw
4/'N|c.
D^+?|Y@N
} _\\ -md:
D<bI2
//线程睡眠 yzR=A%V8A
public static void sleep(int nSecond) je%ldY]/@
{ m2xBS!fm
try{ +6l]]*H
Thread.sleep(nSecond); ?'eq",c#4N
} n*<v]1
catch(Exception e) qM",( Bh
{ Qqc]aVRF
e.printStackTrace (); d]SYP
} "$|Zr
} $'{=R 45Z
$ J1f.YE
//日志 sZg6@s=
public static void log(String sMsg) t>xd]ti
{ 8md*wEjk
System.err.println(sMsg); Y/fJQ6DY
} +&5'uAe
booRrTS
XN;&qR^j
public static void log(int sMsg) wvN`R
{ BI/&dKM
System.err.println(sMsg); q/PNJ#<
} 6B" egYv
} 632bN=>
Zb_apjg[4
<+v{GF#R
/* B{MaMf)
**TestMethod.java `VT>M@i/
*/ nlGHT
package NetFox; eGL<vX
5MF#&v
,SUT~oETP
public class TestMethod { ZVih=Y-w
?X9UTOx
:Ht;0|[H
public TestMethod() r.yK,
{ ///xx/weblogic60b2_win.exe @Jn!0Y1_3
try{ * F4UAQzYb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `@Oa lg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *[}^[J x
SiteFileFetch fileFetch = new SiteFileFetch(bean); $B(kZ
fileFetch.start(); B&0;4
} B^v8,;jZT
catch(Exception e){e.printStackTrace ();} -_N)E ))G
*O~e T
]a'99^?\
} WsGths+[
%,P>%'0
`A@w7J'
public static void main(String[] args) uLR<FpM
{ Fhf<T`
new TestMethod(); bHE2,;o
} A8r^)QJP{
} 8LzBh_J?
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