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)); 4mQ:i7~
} 29 Yg>R!/
for(int i=0;i<nEndPos.length-1;i++) ^yu0Veypy
{ p_)V@7
nEndPos = nStartPos[i+1]; +VI2i~
} (.m0hN!~u
nEndPos[nEndPos.length-1] = nFileLength; oh:g
} xQ^zX7
} $3W[fC
k^S=i_ U
bh3}[O,L A
//启动子线程 u! x9O8y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +i4S^B/8i
for(int i=0;i<nStartPos.length;i++) }O<=!^Y;A
{ %mt|Dl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |94"bDL3~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $cSrT)u:
nStartPos,nEndPos,i); # 0dN!l;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); loLQ@?E
fileSplitterFetch.start(); op/HZa
} 0}PW<lU-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7^ITedW@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >|/NDF=\s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7Xw;TA
nEndPos = " + nFileLength); # ~} 26
// fileSplitterFetch[nPos.length-1].start(); bezT\F/\
)d2<;c
k*w]a
//等待子线程结束 Ky8sLm@
//int count = 0; imZi7o
//是否结束while循环 3uZY.H+H
boolean breakWhile = false; ^j0Mu.+_
~kD/dXt
(lTM5qC
while(!bStop) 0 j:8Ve
{ wbyY?tH
write_nPos(); nz3j";d
Utility.sleep(500); p'0jdb :S
breakWhile = true; =%%\b_\L
mawomna
2+s_*zM-
for(int i=0;i<nStartPos.length;i++) )~rfx
{ |ITp$_S
if(!fileSplitterFetch.bDownOver) sbjAZzrX2i
{ " 2Dz5L1v
breakWhile = false; <IC=x(T
break; 26G2. /**<
} SsIy;l
} 1y2D]h/'
if(breakWhile) {Uz@`QO3
break; JN .\{ Y
+?w 7Nm`
*!$4
//count++; m$ )yd~
//if(count>4) hq6B pE
// siteStop(); jr|(K*;
} r/$+'~apTk
c*-8h{}
pEuZsQ
System.err.println("文件下载结束！"); D^baXp8
} J}c57$Z
catch(Exception e){e.printStackTrace ();} wZJpSkcEx
} ug'I:#@2
XZEawJ0
#v0"hFOH,
//获得文件长度 *p`0dvXG2
public long getFileSize() x1:+M]Da
{ (v6tE[4
int nFileLength = -1; w},' 1
try{ DJ_,1F
URL url = new URL(siteInfoBean.getSSiteURL()); #=V%S 2~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I= G%r/3
httpConnection.setRequestProperty("User-Agent","NetFox"); u_;*Ay
MUhC6s\F
w,bILv)
int responseCode=httpConnection.getResponseCode(); QM\vruTB
if(responseCode>=400) D>+&= 5{
{ iS&~oj_-%
processErrorCode(responseCode); w<3}(1
return -2; //-2 represent access is error ZM K"3c9
} ^1s!OT Is
)G\23P
K{.s{;#
String sHeader; 7F5t&
e^&QT
'YIFHn$!
for(int i=1;;i++) M$DJ$G|Z
{ {hGr`Rh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ! E`Tt[
//Utility.log(in.readLine()); l=8)_z;~D
sHeader=httpConnection.getHeaderFieldKey(i); 9uV/G7Geq
if(sHeader!=null) $Dq=UzQI
{ l+Dl~o}
if(sHeader.equals("Content-Length")) #4%4iR5%
{ )IPnSh/<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QWH1xId
break; O<Qa1Ow7f
} 7?-eR-
} )z&0 g2Am
else \HLI y
break; 9!b,!#=
} !sQ$a#Ea
} )SQ*"X4"
catch(IOException e){e.printStackTrace ();} ?BT$@h
catch(Exception e){e.printStackTrace ();} +6|Ys
O{zY(`[
C7[ge&
Utility.log(nFileLength); jCDZ$W89
MH[Zw$
C9E l {f
return nFileLength; )A:2y +
} %y)5:]
et(/`
-}`ES]
//保存下载信息（文件指针位置） rUEoz|e4a
private void write_nPos() ^"7tfo8
{ TU&6\]yF_
try{ S8*VjG?T\
output = new DataOutputStream(new FileOutputStream(tmpFile)); ("0@_05OH
output.writeInt(nStartPos.length); dya]^L}fL
for(int i=0;i<nStartPos.length;i++) T=35?
{ }ddwL
// output.writeLong(nPos); xoF]r$sC8
output.writeLong(fileSplitterFetch.nStartPos); -fw0bL%0
output.writeLong(fileSplitterFetch.nEndPos); h>-JXuN
} 4d4le
output.close(); }M'h5x
} q$z#+2u
catch(IOException e){e.printStackTrace ();} #gq4%;
catch(Exception e){e.printStackTrace ();} RBIf6oxdE
} 2 *IF
=]&?(Gq
LI_>fuv"8
//读取保存的下载信息（文件指针位置） ^'.=&@i-
private void read_nPos() K-IXAdx
{ NsJt=~
try{ hYMIe]kJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;<`F[V Zau
int nCount = input.readInt(); ?P@fV'Jo
nStartPos = new long[nCount]; ztf VXmi'
nEndPos = new long[nCount]; |!{Q4<
for(int i=0;i<nStartPos.length;i++) OLUQjvnU
{ G3n* bv
nStartPos = input.readLong(); @iK=1\-2
nEndPos = input.readLong(); T0s7aw[zm
} wNL!T6"G
input.close(); z!;n\CV@
} 8*kZ.-T B
catch(IOException e){e.printStackTrace ();} }3:DJ(Y
catch(Exception e){e.printStackTrace ();} fL.;-
} q4{Pm $OW
# eqt{
F,Y,0f@4U9
private void processErrorCode(int nErrorCode) `fh^[Q|4n0
{ UMwB.*
System.err.println("Error Code : " + nErrorCode); 0cZyO$.
} 35z]pn%L
D5fJuT-bp
o6sL~*hQ
//停止文件下载 E*ybf'
public void siteStop() (Z5=GJM?$
{ ~ ui/Qf2|
bStop = true; \o !
for(int i=0;i<nStartPos.length;i++) Cnd70tbD )
fileSplitterFetch.splitterStop(); _H}y7
/Y5I0Ko Uw
E0[!jZ:c
} ;tTM3W-h
} :J]S+tQ)
//负责部分文件的抓取 w]]`/`
**FileSplitterFetch.java ]\5@N7h
*/ ;~T)pG8IS
package NetFox; 6} "?eW
^tX+<X
pq_DYG]
import java.io.*; ~K%]9
import java.net.*; $l-|abLELz
f gI.q
P`6 T;|VDk
public class FileSplitterFetch extends Thread { 75i M_e\
i@e.Uzn
/*p4(D_A
String sURL; //File URL d,[.=Jqv[
long nStartPos; //File Snippet Start Position S+H#^WSt
long nEndPos; //File Snippet End Position c\FyX\i
int nThreadID; //Thread's ID 6G6Hg&B
boolean bDownOver = false; //Downing is over nL!h hseH
boolean bStop = false; //Stop identical RrKAgw
FileAccessI fileAccessI = null; //File Access interface a OR}
I8HUH*|)n
{:m5<6?x)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dVc;Tt
{ q# gZ\V$I
this.sURL = sURL; oc'#sE
this.nStartPos = nStart; HRIf)n&~f
this.nEndPos = nEnd; *V#v6r7<Y/
nThreadID = id; UXD?gK1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7Z5,(dH>
} Ht+ng
qY\zZ
:|`'\%zW-
public void run() g0I<Fan
{ g!~&PT)*
while(nStartPos < nEndPos && !bStop) hY+3PNiI@
{ B[ae<V0k
ka{9{/dz3
X@Eq5s
try{ hKtOh
URL url = new URL(sURL); I9*o[Jp5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dvxD{UH
httpConnection.setRequestProperty("User-Agent","NetFox"); AbUU#C7
String sProperty = "bytes="+nStartPos+"-"; Le9r7O:
httpConnection.setRequestProperty("RANGE",sProperty); 6CO>Tg:%
Utility.log(sProperty); _/ j44q
S<Q8kW:
\<|a>{`7]i
InputStream input = httpConnection.getInputStream(); d|TRP,y
//logResponseHead(httpConnection); hor ok:{
?I}jsm1)
/' L20aN2
byte[] b = new byte[1024]; X0b :Oiw
int nRead; p9R`hgx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G+4a%?JH
{ g*t.g@B<2
nStartPos += fileAccessI.write(b,0,nRead); 7}Z.g9<
//if(nThreadID == 1) [UNfft=K3P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); deaxb8'7
} mhJ>5z
pW8pp?
9UOx~Ty
Utility.log("Thread " + nThreadID + " is over!"); 1jo.d
bDownOver = true; Oz^+;P1
//nPos = fileAccessI.write (b,0,nRead); w$A*|^w1
} TCU|k ,
catch(Exception e){e.printStackTrace ();} z%ljEI"<C
} kr8NKZ/
} (~-q}_G;Q
hw_7N)}
./kmI#gaV
//打印回应的头信息 QC~B8]
public void logResponseHead(HttpURLConnection con) q "bpI8j
{ aFo%B; 8m
for(int i=1;;i++) v0X5`VV
{ ^]'p927
String header=con.getHeaderFieldKey(i); ,!kyrk6
if(header!=null) [rTV)JsTb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i3: sV5
Utility.log(header+" : "+con.getHeaderField(header)); r!Eo8C
else ( NjX?^
break; _kH#{4`Hw
} la)f\Nk
} )[9L|o5D
&IT'%*Y:V
S7aSUt!
public void splitterStop() $f1L<euH
{ ] 5P{*
bStop = true; oLruYSaD
} ++,mM7a
BOL_kp"
b_V)]>v+
} "4g1I<
7azxqa5:
MLBZmM '
/* 9-Ib+/R0
**FileAccess.java (Egykh>
*//文件访问(定位，写) 9%zR?u
package NetFox; "45BOw&72G
import java.io.*; _rs#h)
v{% /aw
uT-WQ/id
public class FileAccessI implements Serializable{ [&{"1Z
r4D66tF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;"Ot\:0
RandomAccessFile oSavedFile; zLxWyPM0;
long nPos; L~mL9[(,
~MhPzu&B
._FgQ``PL
public FileAccessI() throws IOException ' >\*
{ 'HqAm$V+
this("",0); *JpEBtTv=5
} (|6qN
nIsi
YF:NRY[i
public FileAccessI(String sName,long nPos) throws IOException eM9~&{m.
{ jG.*tuf
oSavedFile = new RandomAccessFile(sName,"rw"); RMi 2Ip
this.nPos = nPos; LXXxwIBS
oSavedFile.seek(nPos); a,j!B hu
} eQ9x l
*Lh0E/5
"(C}Dn#
public synchronized int write(byte[] b,int nStart,int nLen) e<C5}#wt
{ /FYa{.Vlr
int n = -1; qp{NRNkQ
try{ ;3?M?E/$s
oSavedFile.write(b,nStart,nLen); RK'( {1
n = nLen; 6&u,.
} 9CN /v
catch(IOException e) 9J|YP}%
{ G2jEwi
e.printStackTrace (); hCo&SRC/5
} JI*ikco-
F2:7UNy,
u8W*_;%:
return n; $ o t"Du
} DI&xTe9k
)Z;Y,g
qC6Q5F
} w}(xs)`num
[p7le8=
!t_,x=
/* u>(Q& 25
**SiteInfoBean.java ,\qo
*/ Maxnk3n
package NetFox; 92VAQU6
jkdNisq37
w"BTu-I
public class SiteInfoBean { h)<42Y
8:A<PV!+
pDKJLa
private String sSiteURL; //Site's URL W*s`1O>
private String sFilePath; //Saved File's Path 4]+ ^K`
private String sFileName; //Saved File's Name 6F(yH4
private int nSplitter; //Count of Splited Downloading File {jc~s~<#
We4 FR4`
vc!S{4bN
public SiteInfoBean() YT3QwN9
{//nSplitter的缺省值为5 O%)9tFT
//default value of nSplitter is 5 IB?A]oN1{
this("","","",5); Xt7'clr
} '&9a%
B{K'"uC
PIrUls0}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q72wg~%w
{ f,-|"_5;
sSiteURL= sURL; pIrAGA;
sFilePath = sPath; CVUJ(D&Q
sFileName = sName; 1uH\Bn]p?
this.nSplitter = nSpiltter; I|ULf
G|MDo|q]
+ zrwz\
} $yc,D=*Isi
'qP^MdoE%~
HOD2/
public String getSSiteURL() tFSdi.|G=
{ k}O|4*.BT
return sSiteURL; 9D| FqU |
} ef.lM]cO
)N6R#
p/5!a~1'xN
public void setSSiteURL(String value) q-o>yjT~
{ \=_8G:1
sSiteURL = value; 0Fw\iy1o
} ps[6)d)o
EiN.VU `
'wZy: c
public String getSFilePath() -'N#@Wdr
{ Nb8<8O ^
return sFilePath; %1<p1u'r?#
} lcP@5ZW
,C&>mv xA
N1Z8I:
public void setSFilePath(String value) |{jAMC0#
{ I[`2MKh
sFilePath = value; !Q3Snu=
} %zD-gw>
UxvsSHi
b(yO
public String getSFileName() KALg6DZe:
{ Gu}x+hG
return sFileName; 5HIpoj;\(
} b mm@oi
6m" 75
_9@?Th&_e
public void setSFileName(String value) bSR<d
{ '; dW'Uwc
sFileName = value; E5t+;vL~
} 1;xw)65
=5/;h+bk+3
PHK#b.B>a8
public int getNSplitter() 0;H6b=
{ h.9Lh ;j
return nSplitter; oe*&w9Y}&
} yki k4MeB
^sOm7S{
,%'0e/
public void setNSplitter(int nCount) /T(\}Z
{ G}-.xj]
nSplitter = nCount; 4d 3Znpf
} &v-V_.0(H
} /C:'qhY,
xI4I1"/
u/[]g+
/* \l:g{GnoT
**Utility.java |Hm'.-
*/ ?iLd5 Z
package NetFox; ,?`1ve_K<
IeB6r+4|
NslA/"*
public class Utility { U>+~.|'V9
N39nJqo>"
QP[a^5;Tt
public Utility() u,akEvH~a
{ #VV.[N
Doh|G:P]#
e87- B1`
} 05KoxFO?
T"H)g
//线程睡眠 ]`sIs= _[
public static void sleep(int nSecond) W|#ev*'F
{ |{PJT#W%
try{ `zp2;]W
Thread.sleep(nSecond); '^l^gW/|\
} 0#[f2X62B
catch(Exception e) Kyp0SZp[
{ w;EXjl;X O
e.printStackTrace (); V"H7zx
} NoO+xLHw8
} S8OVG4-
]kkBgjQbS
//日志 ,imvA5
public static void log(String sMsg) "-n%874IT
{ =_=Z;#`cXk
System.err.println(sMsg); ARdGh_yJ&
} eAsX?iaH
pRwGv
vif8{S
public static void log(int sMsg) KKjxg7{K
{ +%Yc4
System.err.println(sMsg); I26gGp
} %Sn6*\z
} :pDY
~BvY8\@B
Yb\\ w<@g
/* iEpq*Qj
**TestMethod.java ;:4P'FWm^
*/ 'K3s4x($
package NetFox; vzcBo%
{?/8jCVd
`GQiB]Z
public class TestMethod { ,![Du::1
ZJ9Jf2 c
,B%fjcn
public TestMethod() t\pK`DM-[
{ ///xx/weblogic60b2_win.exe !p,hy`
try{ G|-\T(&J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `_1(Q9Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); e[QxFg0E
SiteFileFetch fileFetch = new SiteFileFetch(bean); )4~sQ^}
fileFetch.start(); $}nh[@
} '^Utbp2<
catch(Exception e){e.printStackTrace ();} R6Zj=l[
8b(1ut{
V(2,\+t
} +^*5${g;@H
F@$RV_M
_@!QY
public static void main(String[] args) ^.#X<8hr
{ 3kiE3*H
new TestMethod(); 9Yl8ndP^E
} /S]:dDY9K
} [vWkAJ'K
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