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)); xU>WEm2
} a#y;dK
for(int i=0;i<nEndPos.length-1;i++) l%puHZ)t
{ 5Y'qaIFR
nEndPos = nStartPos[i+1]; n:\~'+$
} xH(lm2kvT
nEndPos[nEndPos.length-1] = nFileLength; 9_rYBX
} NAQAU *yP
} E+R1 !.
)Y6 +
i6tf2oqO7
//启动子线程 ith 3=`3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Bp`]
for(int i=0;i<nStartPos.length;i++) kmsb hYM)
{ I{9QeRI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >WQMqQ^t@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NI}yVV
nStartPos,nEndPos,i); st3l2Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EZy)A$|
fileSplitterFetch.start(); QP^Cx=
} l7259Ro~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]&xk30
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); otl0JHt*+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _jI,)sr4ic
nEndPos = " + nFileLength); AOWmzu{zw
// fileSplitterFetch[nPos.length-1].start(); zRl3KjET
:W:K:lk
lhz{1P]s
//等待子线程结束 qL&[K>2z
//int count = 0; EC6DW=
//是否结束while循环 DV+xg3\(>1
boolean breakWhile = false; ox>^>wR*
.TMs bZ|j
^aMg/.j
while(!bStop) 5uNJx5g
{ 4 \K7xM!
write_nPos(); S)k*?dQ##R
Utility.sleep(500); *1 ]uH e
breakWhile = true; EXwo,?I
>CgTs
1i"WDu*h3
for(int i=0;i<nStartPos.length;i++) 5k3n\sqZA
{ <fjX[l<Uz
if(!fileSplitterFetch.bDownOver) {3p4:*}
{ Av$^
breakWhile = false; 7 60Y$/Wz
break; ?m=N]!n
} 1k5Who@
} :q7Wy&ow
if(breakWhile) dh*ZKI^@(
break; UcDS9f_87
*_{j=sd
[vK^Um
//count++; |zNX=mAV
//if(count>4) _AYK435>N
// siteStop(); o\<ULW*
} *@r/5pM2}
}bpQq6ZF
+L|?~p`V
System.err.println("文件下载结束！"); M~#gRAUJ
} %@ODs6 R0
catch(Exception e){e.printStackTrace ();} mpEK (p
} p2[n$61
_476pZ_
N/'b$m5= S
//获得文件长度 swoQ'
public long getFileSize() BB$>h}
{ d>&,9c%
int nFileLength = -1; #m<nAR
try{ kr5">"7
URL url = new URL(siteInfoBean.getSSiteURL()); VimE@Hz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); He/8=$c%
httpConnection.setRequestProperty("User-Agent","NetFox"); qu6D 5t
7qLpZ/
C12Fl
int responseCode=httpConnection.getResponseCode(); Nw/ ku
if(responseCode>=400) eKLZt%=
{ `$<.pOm
processErrorCode(responseCode); |'8Nh
return -2; //-2 represent access is error Nk 8B_{
} O67W&nz
mPK:R^RjG&
o>i4CCU+
String sHeader; g i-$ZFzB
4*#18<u5
H8zK$!
for(int i=1;;i++) V)-+Fd,=
{ V-2(?auZd
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |t&>5HM
//Utility.log(in.readLine()); _LUhZlw
sHeader=httpConnection.getHeaderFieldKey(i); \0I_<
if(sHeader!=null) ,RI Gc US
{ VUGmi]qd
if(sHeader.equals("Content-Length")) I-)+bV G
{ 4Zddw0|2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GL0L!="!
break; bMu+TgAT,
} vHc%z$-d
} qzLPw*;
else SC!RbW@3
break; #ut
} ]e^&aR5f"
} Jk11fn;\>
catch(IOException e){e.printStackTrace ();} JT7nG.9
catch(Exception e){e.printStackTrace ();} G1tY)_-8[
o5O#vW2Il&
I)6+6pm
Utility.log(nFileLength); 9dLV96
KVaiugQ
*3FKt&v 0
return nFileLength; 2'\H\|
} dNH08q8P
g\:[ 55;8
1~`fVg
//保存下载信息（文件指针位置） cN6X#D
private void write_nPos() EhvX)s
{ %y[h5*y*
try{ DGF5CK.O
output = new DataOutputStream(new FileOutputStream(tmpFile)); E\EsWb
output.writeInt(nStartPos.length); glxsa8
for(int i=0;i<nStartPos.length;i++) ~2N"#b&J
{ J#(LlCs?@c
// output.writeLong(nPos); j#x6
output.writeLong(fileSplitterFetch.nStartPos); RFcv^Xf
output.writeLong(fileSplitterFetch.nEndPos); 9uO 2Mm
} IGQFtO/x
output.close(); RnE4<Cy
} v^NIx q}U
catch(IOException e){e.printStackTrace ();} >J?fl8
catch(Exception e){e.printStackTrace ();} o4,6.1}
} SmH=e@y~Lx
/NFj(+&g+
Fb>?1i`RN
//读取保存的下载信息（文件指针位置） 1{.|+S Z!
private void read_nPos() `?@}>.
{ u@M,qo`
try{ ]Sz:|%JP1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MYvY]Jx3
int nCount = input.readInt(); n\'4
nStartPos = new long[nCount]; B{#I:Rs9
nEndPos = new long[nCount]; @ioJ]$o7
for(int i=0;i<nStartPos.length;i++) [5b--O
{ [ /b2=>
nStartPos = input.readLong(); j0aXyLNX
nEndPos = input.readLong(); lU\[aNs
} ]^7@}Ce_
input.close(); L}b.ulkMD
} !hy-L_wL]
catch(IOException e){e.printStackTrace ();} ! E5HN :#
catch(Exception e){e.printStackTrace ();} Vwf$JdK%&l
} 3M7/?TMw{6
H@>` F
i$#;Kpb`^
private void processErrorCode(int nErrorCode) 5H9z4-i x?
{ lNh70G8^p
System.err.println("Error Code : " + nErrorCode); AKfDXy
} Eyqa?$R
C2I_%nU Z1
p%Vt#?q
//停止文件下载 &`r-.&Y
public void siteStop() -3*]G^y2
{ mdg8,n
bStop = true; k%#EEMh
for(int i=0;i<nStartPos.length;i++) 4.aZ#c91_
fileSplitterFetch.splitterStop(); FVbb2Y?R
f~R(D0@
/-'}q=M
} %)1?TU
} ;[YG@-"XZ
//负责部分文件的抓取 fU}ub2_in
**FileSplitterFetch.java "+nRGEs6
*/ @*XV`_!h
package NetFox; 4e7-0}0
MJO-q $)c
ksUcx4;a@F
import java.io.*; -d/ =5yxL
import java.net.*; d&Zpkbh"
yx[/|nZDC4
'<)n8{3Q5w
public class FileSplitterFetch extends Thread { Q&tG4f<
L`TLgH&?R
U'_Q>k
String sURL; //File URL ET*SB
long nStartPos; //File Snippet Start Position Of#u
long nEndPos; //File Snippet End Position Mfuv0P~
int nThreadID; //Thread's ID 4F:\-O
boolean bDownOver = false; //Downing is over f'RX6$}\1X
boolean bStop = false; //Stop identical R) h#Vc(
FileAccessI fileAccessI = null; //File Access interface 'JE`(xD
V=l0(03j~
Ic<2QknmP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Wvh#:Z
{ `$9x1dx
this.sURL = sURL; i&fuSk EP
this.nStartPos = nStart; &6!)jIWJ
this.nEndPos = nEnd; v{4$D~I
nThreadID = id; K5h
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BDDlQci38
} O0v}43J[
F/{!tx
T'9'G M
public void run() Sz`,X0a
{ t3_O H^
while(nStartPos < nEndPos && !bStop) ;[DU%f
{ zC!t;*8a
$h"\N$iSq
9cF[seE"0
try{ ]%H`_8<gc
URL url = new URL(sURL); >tr}|>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tDcT%D {:
httpConnection.setRequestProperty("User-Agent","NetFox"); q<|AZ2Ai
String sProperty = "bytes="+nStartPos+"-"; #trK^(
httpConnection.setRequestProperty("RANGE",sProperty); (?c"$|^J
Utility.log(sProperty); Btn?N
7n<{tM
!Ai@$tl[S
InputStream input = httpConnection.getInputStream(); [9L:),&u
//logResponseHead(httpConnection); FW4<5~'
W{+2/P
3nQ`]5.Q w
byte[] b = new byte[1024]; \M^bD4';>
int nRead; Qw*|qGvy^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4+8@`f>s
{ f$$/H>MJ
nStartPos += fileAccessI.write(b,0,nRead); {;1\+f
//if(nThreadID == 1) H7n>Vx:L-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8GUX{K
} C1)!f j=
k y7Gwc
vk^xT
Utility.log("Thread " + nThreadID + " is over!"); n7[V&`e_
bDownOver = true; 1Pu~X \sO
//nPos = fileAccessI.write (b,0,nRead); lL3U8}vn
} *g2x%aZWbG
catch(Exception e){e.printStackTrace ();} Jnov<+
} V 5mTP'
} u6JM]kR
V)25$aKW7
}Sv:`9=
//打印回应的头信息 Y$_B1_
public void logResponseHead(HttpURLConnection con) wc4=VC"y
{ 0GeTSFj
for(int i=1;;i++) WOap+
{ TC*g|d @b
String header=con.getHeaderFieldKey(i); )y$(AJx$
if(header!=null) #"~<HG}bR/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y<Ot)fa$
Utility.log(header+" : "+con.getHeaderField(header)); ~c `l@:
else " H\k`.j
break; UCjld
} g($2Dk_F2
} NBGH_6DROw
e\L8oOk#r
YOO+R{4(
public void splitterStop() ?e 4/p
{ 5\nAeP
bStop = true; F)eelPZ+,
} 4V`G,W4^J
c^W)07-X5y
a:w#s}bL
} &^jXEz;
` Sz}`+E
_t^&Ah*
/* Dlvz)
**FileAccess.java NzvXN1_%
*//文件访问(定位，写) k<?b(&`J
package NetFox; \9T7A&
import java.io.*; K$=zi}J W
6'f;-2
Q$"D]!G
public class FileAccessI implements Serializable{ FYQS)s
;2QP7PrSY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |A(Iti{v
RandomAccessFile oSavedFile; tCt#%7J;a
long nPos; eaU
p`qgrI`
?:0Jav
public FileAccessI() throws IOException Mo|2}nf
{ (E1~H0^
this("",0); >m\(6x8RE
} m8[j #=h
OjA,]Gv6
");a3hD
public FileAccessI(String sName,long nPos) throws IOException `R^gU]Z,
{ $6IJP\
oSavedFile = new RandomAccessFile(sName,"rw"); Nh+H9
this.nPos = nPos; 5z)~\;[ -
oSavedFile.seek(nPos); }Q+|W=2t
} JBZ@'8eqi]
WcGS9`m/
@=u3ZVD
public synchronized int write(byte[] b,int nStart,int nLen) ns4,@C$
{ I>$&-i
int n = -1; OY({.uVdX
try{ hDGF7
oSavedFile.write(b,nStart,nLen); >H,*H;6
n = nLen; owv[M6lbD
} ^-'fW7[m
catch(IOException e) _yR^*}xJb
{ K3uRs{l|
e.printStackTrace (); Tlr v={
} uB?ZcF}Tk
"0TZTa1e
!;'=iNOYR
return n; lp8v0e4
} dj%!I:Q>u
<1!O1ab
A3*!"3nU
} X@FN|Rdh
8 Fbo3
hi[pVk~B)
/* 5!9zI+S|=`
**SiteInfoBean.java Flb&B1
*/ xgtR6E^k
package NetFox; EoDA]6?Lj
-UT}/:a
O#r%>;3*
public class SiteInfoBean { ;dhQN}7
&%Tj/Qx
V(*(F7+
private String sSiteURL; //Site's URL cB&:z)i4
private String sFilePath; //Saved File's Path zbPqYhJzA
private String sFileName; //Saved File's Name RD&PDXT4
private int nSplitter; //Count of Splited Downloading File Z3!`J&
apxph2yvS
u]@['7
public SiteInfoBean() wz8yD8M
{//nSplitter的缺省值为5 )!T/3|C
//default value of nSplitter is 5 Xn ;AZu^'R
this("","","",5); A+{VGP^
} (7*}-Uy[C
6W UrQFK
xkAK!uVy
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bZV/l4TU
{ jz0T_\8D`
sSiteURL= sURL; 3;Fhg!ZO
sFilePath = sPath; vvOV2n.WD
sFileName = sName; B>.qd
this.nSplitter = nSpiltter; zx7{U8*`<
&kw@,];4Z
5kXYeP3:
} ehY5!D1Q
Rlirs-WQ
:Ux_qB
public String getSSiteURL() 8~gLqh8^V
{ "zy7C*)>r
return sSiteURL; #LOwGJ$yVz
} 40 0#v|b
v.5+7,4
YK~%xo
public void setSSiteURL(String value) 1-QS~)+
{ EJ@ ~/)<
sSiteURL = value; ~PNub E
} W@!S%Y9
;9g2?-svw
OZ!^ak
public String getSFilePath() 4E?Oky#}-
{ 6LZ;T.0o
return sFilePath; S21,VpW\
} ^Zp>G{QL{
dcT80sOC
j <RrLn_
public void setSFilePath(String value) _<2E"PrT
{ 0qT%!ku&
sFilePath = value; Wo,?+I
} 29q _BR *:
Z EO WO
^G-@06/!
public String getSFileName() C"enpc_C/
{ }:#P)8/v>%
return sFileName; =mmWl9'mJ
} ^zgo#J5O
C{wEzM:
M& CqSd
public void setSFileName(String value) \5cpFj5%
{ n{SJ_S#a.a
sFileName = value; A.w:h;7
} Dn}Jxu'(
2dgd~
!5?<% *
public int getNSplitter() *_g$MI
{ YT8F#t8
return nSplitter; 3{(/x1a,4
} ua `RJ
NW)1#]gg%
gv{ >`AN
public void setNSplitter(int nCount) j1HW._G
{ ^y4Z+Gu[
nSplitter = nCount; /|&*QLy
} kz7(Z'pw
} Fea(zJ_
/JU.?M35
Oz#{S:24M+
/* vSLtFMq^(
**Utility.java G<;*SYAb
*/ c_l"I9M#r
package NetFox; ji,kkipY?w
RY*U"G0#w
qb` \)X]9
public class Utility { EDs\,f}
,3 u}x,
O%HHYV%[m
public Utility() ,wdD8ZT'Ip
{ hwNf~3eJk
h3@v+Z<}
t<?,F
} Y:)e(c"A
B^jc3 VsR
//线程睡眠 fa2kG&, _
public static void sleep(int nSecond) S`m]f5u|
{ BJo*'US-Q
try{ "8zDbdK
Thread.sleep(nSecond); ^L&iR0
} , SnSW-P
catch(Exception e) K,:N
{ 63x?MY6
e.printStackTrace (); '>C5-R:O
} yJe>JK~)
} Ok\7y-w^
njA#@fU
//日志 Nu~lsWyRI5
public static void log(String sMsg) % +\."eC
{ Hg (Gl
System.err.println(sMsg); =zs`#-^8
} ]L}dzA?:
j^2j&Ta
U_c*6CK
public static void log(int sMsg) DkAAV9*
{ yyy|Pw4:Z
System.err.println(sMsg); I[X772K
} 6Sn.I1Wy
} r0 uwPf
NSA-}2$
Tc3yS(aq
/* liz~7RY4
**TestMethod.java WvZ8/T'x
*/ 0NX,QD
package NetFox; c_!cv":s
l0i^uMS
"i W"NFO
public class TestMethod { g5r(>,vY
! #2{hQRu
lBGQEP3;
public TestMethod() .y:U&Rw4
{ ///xx/weblogic60b2_win.exe mBON$sF|
try{ b<gr@WF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >!)DM]Ri
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Jma1N;d
SiteFileFetch fileFetch = new SiteFileFetch(bean); P\)iZiGc
fileFetch.start(); cD'V>[h
} fw{gx
catch(Exception e){e.printStackTrace ();} Q6I:"2u1
:tv,]05t
Vj>8a)"B5a
} 4d;8`66O
gEE\y{y
by/jYg)+
public static void main(String[] args) Hc(OI|z~
{ kt$jm)UI~l
new TestMethod(); L4y4RG/SJ:
} x0:m-C
} ))'<_nD
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