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)); _xsYcw~)
} je%12DM
for(int i=0;i<nEndPos.length-1;i++) =?aB@&
{ __npX_4%S
nEndPos = nStartPos[i+1]; #O ]IXo(5z
} aoX$,~oI5
nEndPos[nEndPos.length-1] = nFileLength; 4!|ar?Zy
} @SXgaWr
} gH.^NO5\'
rP_)*)
2G;d2LR:
//启动子线程 |&Wo-;Ud
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y9<Fv|Ric
for(int i=0;i<nStartPos.length;i++) rJwJ5U
{ [X]o`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t]XJq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), UkKpSL}Q2
nStartPos,nEndPos,i); qo|iw+0Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v_h{_b8
fileSplitterFetch.start(); ?sE21m?b-
} gV BV@v!W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $!w%=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (%, '
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @su,w,xLS
nEndPos = " + nFileLength); nX'.'3
// fileSplitterFetch[nPos.length-1].start(); /+YWp>6LU
V:18]:
_A*0K,F-
//等待子线程结束 SF7 Scd
//int count = 0; v<W++X7z
//是否结束while循环 ;<H2N0qJ(
boolean breakWhile = false; /.bwwj_;
J$[Vm%56
Sa5y7
while(!bStop) s5e}X:
{ 4G ?k31,k
write_nPos(); dZZ/(oE>
Utility.sleep(500); g-36Q~`9v
breakWhile = true; )-gyDA
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va<pHSX&I@
for(int i=0;i<nStartPos.length;i++) rD gl@B3
{ l"CONzm!
if(!fileSplitterFetch.bDownOver) |Sm/Uq(c
{ 8qveKS]vZ
breakWhile = false; zT8K})#
break; T8LwDqio
} F_`Gs8-VH
} iDr0_y*t
if(breakWhile) IT|CfQ [D
break; pP&~S<[
u#<]>EtbB
1)y}.y5S
//count++; (X/JXu{
//if(count>4) 2z:9^a/]Na
// siteStop(); qS>el3G
} A\>qoR!Y
&/p9+gd
PR0]:t)E
System.err.println("文件下载结束！"); /<~IKVz\&
} t*#T~3p
catch(Exception e){e.printStackTrace ();} J5wq}<8
} Zh*I0m
w'C(? ?mH
FU zY&@Y
//获得文件长度 = 4L.
public long getFileSize() e!#:h4I
{ wuCODz@~
int nFileLength = -1; nM#\4Q[}Jh
try{ lUmaNZ
URL url = new URL(siteInfoBean.getSSiteURL()); %?ad.F+7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -VL3em|0
httpConnection.setRequestProperty("User-Agent","NetFox"); Jh1fM`kB5K
#\qES7We6
MeC@+@C
int responseCode=httpConnection.getResponseCode(); ~7|z2L
if(responseCode>=400) ^<c?Ire
{ H`sV\'`!}
processErrorCode(responseCode); TD'1L:mv
return -2; //-2 represent access is error oT OMqR{"
} %0 S0"t
v2NzPzzyb
S"*wP[d.9
String sHeader; zKo,B/Ke4
6Y=)12T
i{.!1i:
for(int i=1;;i++) [||$1u\%
{ raCxHY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B^Vb=* QRo
//Utility.log(in.readLine()); y7JJ[:~~
sHeader=httpConnection.getHeaderFieldKey(i); SyI#Q[f'_
if(sHeader!=null) \O56!,k
{ 9496ayi
if(sHeader.equals("Content-Length")) eG.?s;J0
{ pV_2JXM~@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *5^h>Vk/
break; :0/I2:
} *`[LsG]ZF
} bLg1Dd7Q
else 5^qI6 U
break; WE\V<MGS/
} c(fwl`y!x
} %j yLRT]H
catch(IOException e){e.printStackTrace ();} R b'"09)$
catch(Exception e){e.printStackTrace ();} b@Fa|>"_
wNn6".S
wml`3$"cf
Utility.log(nFileLength); s<:J(gD
k7?(IU
Re`= B
return nFileLength; u?!p[y6
} cYK3>p A
TWMD f
278 6tZF,
//保存下载信息（文件指针位置） SKGYmleR
private void write_nPos() vq|W&
{ )l^w _;
try{ 1r$q $\
output = new DataOutputStream(new FileOutputStream(tmpFile)); W<t,Ivg
output.writeInt(nStartPos.length); DF<_Ns!
for(int i=0;i<nStartPos.length;i++) YkTEAI|i
{ }JS?42CTaV
// output.writeLong(nPos); JVRK\A|R
output.writeLong(fileSplitterFetch.nStartPos); 6u7>S?
output.writeLong(fileSplitterFetch.nEndPos); "!2Fy-Y
} \\_Qv
output.close(); $%LjIeVA5
} p\Jz<dkN1
catch(IOException e){e.printStackTrace ();} |VIBSty2d
catch(Exception e){e.printStackTrace ();} k z<We/
} VgOj#Z?K
ds`a6>746
bV}43zI.
//读取保存的下载信息（文件指针位置） vI4St;
private void read_nPos() zUeS7\(l
{ Rh iiQ
try{ wT;D<rqe`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !RV}dhI
int nCount = input.readInt(); P7Kp*He)
nStartPos = new long[nCount]; Eg>MG87
nEndPos = new long[nCount]; _jp8;M~Z
for(int i=0;i<nStartPos.length;i++) F9N)UW:w
{ M%Ov6u<I8
nStartPos = input.readLong(); ))<3+^S0V\
nEndPos = input.readLong(); RV-7y^[]^
} BDpeAF8z
input.close(); v*kTTaU&
} VHJOj
catch(IOException e){e.printStackTrace ();} F]xo*
catch(Exception e){e.printStackTrace ();} '6WaG hvO
} .7" f~%&oP
(h%!Kun
T0i_X(_
private void processErrorCode(int nErrorCode) ]oj 2
{ :Fm)<VN"
System.err.println("Error Code : " + nErrorCode); s/8>(-H#
} p3&w/K{L6w
G}d@^9FkE
r\Zz=~![<
//停止文件下载 ;kY'DKL(
public void siteStop() !>+YEZ"
{ b k 30d
bStop = true; *22}b.)
for(int i=0;i<nStartPos.length;i++) >zVj+
fileSplitterFetch.splitterStop(); QOMh"wC3
{'T=&`&OF
Q u{#4qToA
} *s}dtJ
} "9aiin
//负责部分文件的抓取 ; 7k@_
**FileSplitterFetch.java Mz_*`lRN
*/ |}t[-a
package NetFox; ;vnG
\^i/:
C[gy{40}
import java.io.*; CNQ>J`4
import java.net.*; yc?+L;fN
C[z5& x2
t[|^[%i
public class FileSplitterFetch extends Thread { q3n(Z
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rfku]A$
String sURL; //File URL ?*){%eE
long nStartPos; //File Snippet Start Position dX?8@uzu
long nEndPos; //File Snippet End Position Q)#+S(TG
int nThreadID; //Thread's ID lku}I4
boolean bDownOver = false; //Downing is over `C9/=
boolean bStop = false; //Stop identical eJlTCXeZ|
FileAccessI fileAccessI = null; //File Access interface 3!ZndWSHV
A@^Y2:pY
d#'aTmu!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -AWL :<
{ eX;C.[&7;8
this.sURL = sURL; CvS}U%
this.nStartPos = nStart; Z(k7&^d
this.nEndPos = nEnd; )OpB\k
nThreadID = id; d ]R&mp|'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wGr5V!
} !*5vXN
3=SIIMp7=
)*Xd
public void run() *z&m=G\
{ /{QR:8}-Q
while(nStartPos < nEndPos && !bStop) l.NV]up+
{ lu2"?y[2
<?znk8|
6qp2C]9=
try{ VPBlU
URL url = new URL(sURL); ZUPlMHc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pCb3^# &o
httpConnection.setRequestProperty("User-Agent","NetFox"); /Sy:/BQ
String sProperty = "bytes="+nStartPos+"-"; WrP4*6;"
httpConnection.setRequestProperty("RANGE",sProperty); KG=h!]Meq
Utility.log(sProperty); *uoc;6
OiAP%7i9
*c9/ I
InputStream input = httpConnection.getInputStream(); ruiAEC<Ej
//logResponseHead(httpConnection); pu3ly&T#a_
:!Ea.v
5'*v-l,[
byte[] b = new byte[1024]; 4'9yMXR
int nRead; K)=<hL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M*6}#ST
{ ;iEr+
nStartPos += fileAccessI.write(b,0,nRead); "-bsWC
//if(nThreadID == 1) 4AA3D!$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KVQ|l,E, /
} XpS].P9
!} ~K'1"
[ed6n@/O@
Utility.log("Thread " + nThreadID + " is over!"); fR]%:'2k
bDownOver = true; (nL''#Ka
//nPos = fileAccessI.write (b,0,nRead); @'XxMO[Z!<
} ~ A?
catch(Exception e){e.printStackTrace ();} w&VMb&<
} 9OI&De5?=V
} b8o}bm{s
/1OzX'5f
JzI/kH~
//打印回应的头信息 33/aYy
public void logResponseHead(HttpURLConnection con) g<d#zzP"T
{ A|Z'\D0
for(int i=1;;i++) o$disJ
{ A 9\]y%!
String header=con.getHeaderFieldKey(i); iPoh2
if(header!=null) p{c+ +P5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X=_`$ 0
Utility.log(header+" : "+con.getHeaderField(header)); H! IL5@@K
else (4ueO~jb$
break; )}`3haG
} {6E&\
} r92C^h0
@-9u;aL
LNm{}VJ%
public void splitterStop() UTT7a"
{ q4Z9;^S
bStop = true; 0uZ'j
} --X1oC52A
#I]5)XT
.~>Uh3S
} X"'c2gaa_
8}5dyn{cvE
ciQG.]
/* "j(?fVx
**FileAccess.java r0 mXRZC
*//文件访问(定位，写) <]9%Pm#X
package NetFox; n+Bh-aV
import java.io.*; fYv= yP~
F?>rWP
CY{`IZ
public class FileAccessI implements Serializable{ WrzyBG_
i]sz*\P~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =[X..<bW9:
RandomAccessFile oSavedFile; gtizgUS7
long nPos; MGoYL\
YbX3_N&
]6#7TT
public FileAccessI() throws IOException +vR$%
{ XnBpL6"T`
this("",0); Ry5/O?QL
} `F)Q=
eYJ6&).F
5|I2
public FileAccessI(String sName,long nPos) throws IOException e7fA-,DV
{ Sw<V/t
oSavedFile = new RandomAccessFile(sName,"rw"); s*blZdP
this.nPos = nPos; >=<qAkk
oSavedFile.seek(nPos); '%k<? *
} c_oI?D9
DBUhqRfl
E Z^eEDZ
public synchronized int write(byte[] b,int nStart,int nLen) 3F/05}d`
{ ]yzqBbV
int n = -1; }M9R5!=q
try{ )@%wj;>a
oSavedFile.write(b,nStart,nLen); OIT9.c0h
n = nLen; *TacVp
} N;)Y+amg^
catch(IOException e) h"b;e2
{ .Vy*p")"
e.printStackTrace (); Y;JPr
} }YPW@g
b7X-mkF
YJioR4+q
return n; *""JE'wG
} \M@9#bd
@ P[o
vkQ81PEt
} $-Ud&sjn
LdSBNg#3
.iDxq8l
/* vSu|!Xb]
**SiteInfoBean.java pt`^4}
*/ iti~RV,
package NetFox; @O~
;H%&Jht
T2;%@Ghc
public class SiteInfoBean { hWzjn5w3
d@+}_R"c
vY+{zGF
private String sSiteURL; //Site's URL _.Ey_K_1
private String sFilePath; //Saved File's Path =U:9A=uEvS
private String sFileName; //Saved File's Name vrS)VJg`
private int nSplitter; //Count of Splited Downloading File bzI!;P1&
zvvF9
tcovMn'
public SiteInfoBean() Cfizh@<
{//nSplitter的缺省值为5 xjm|ewo
//default value of nSplitter is 5 |7ga9
this("","","",5); +Lq;0tRC
} VxlK:*t`
q T16th[D
w&A&BE^O/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Pc=S^}+
{ UKIDFDn6_
sSiteURL= sURL; cBgdBPDa
sFilePath = sPath; zjyj,jP
sFileName = sName; 8{mQmG4
this.nSplitter = nSpiltter; FQV]/
L&C<-BA/
nG0Uv%?{pj
} c&A;0**K,
--ED]S 8
5&&6e`
public String getSSiteURL() 2r3]DrpJ
{ ] D(laqS;"
return sSiteURL; ?DN4j!/$
} e ]@Ex
(}$~)f#s
Fv[. %tW
public void setSSiteURL(String value) <tT*.nM\
{ -3YsrcJi
sSiteURL = value; Z*/*P4\
} f87>ul!*
'rT@r:6fn
=Mg/m'QI
public String getSFilePath() S6.N)7y
{ o6@Hj+,,
return sFilePath; kR C0iTV'I
} Ihe/P {t]J
/+FZDRf!r
fz)i9D@
public void setSFilePath(String value) Bld%d:i
{ b4_"dg~gK
sFilePath = value; =:fFu,+{
} T?!&a0
}]-SAM
c$<7&{Pb
public String getSFileName() =r<0l=
{ \\j98(i
return sFileName; FZ!KZ!p
} #MZ0Sd8]&
@$5!
:+1S+w
public void setSFileName(String value) RETq S
{ C:$12{I?*
sFileName = value; ?V6+o`bm
} QlbhQkn
DYvi1X6
8"C;I=]8
public int getNSplitter() Jm%hb,
{ 8&AHu
return nSplitter; bLx70$
} GN36:>VWb
sFR'y.
8[\(*E}d!X
public void setNSplitter(int nCount) l)PEg PSRV
{ >R5qhVYFb
nSplitter = nCount; PB !\r}Q
} 'o2V}L'nG
} YF{KSGq
7=.}484>J
/MS*_
/* XxW~4<r
**Utility.java (t.pM P4
*/ yFt'<{z[nL
package NetFox; cZ(7/Pl
B_u+$Odo
&Wj %`T{
public class Utility { .x__X3P>\
l}>gG[q!
/2,s-^
public Utility() sje}E+{[
{ E%g_O_
TQx''$j\
{u BpM9KT
} 7)S;VG k
U=<E,tM
//线程睡眠 MC5M><5\
public static void sleep(int nSecond) &i`\`6 q
{ e+"rL]
try{ opz.kP[e,
Thread.sleep(nSecond); H6<\7W89y
} uJ S+;H
catch(Exception e) >@b70X!J]
{ 8-cB0F=j_
e.printStackTrace (); {nH. _
} JGaS`fKSk
} Sr_]R<?
y8U|A0@$`
//日志 *Z7W'-
public static void log(String sMsg) f"h{se8C
{ a;p3Me7
System.err.println(sMsg); LC5NB{b\%>
} XVi?-/2
X*F#=.lh
W M/pP?||
public static void log(int sMsg) I;`)1
{ YQ>M&lnQ<
System.err.println(sMsg); [guJd";
} ~4th;#'
} @?_<A%hz
S#{e@ C
M%f96XUM
/* i(q%EMf
**TestMethod.java H*_:IfI!
*/ #uNQ+US0
package NetFox; "Vp+e%cqG
{z?e<
'xAfcP[^
public class TestMethod { clQN@1] M
7O{c>@\
/?l@7
public TestMethod() P@'<OI
{ ///xx/weblogic60b2_win.exe hV_eb6aj}P
try{ #$(F&>pj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4oLrCQZ\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ![os5H.b#q
SiteFileFetch fileFetch = new SiteFileFetch(bean); =iy%;>I`
fileFetch.start(); TD+V.}
} 2<Pi2s'
catch(Exception e){e.printStackTrace ();} vMJv.O>HW
*axOen
H kDT14 `&
} r8XY"<
50Z$3T
=LHE_ AA
public static void main(String[] args) q4$zsw
{ sHO6y0P
new TestMethod(); Le"$ksu>
} nG&=$7x^
} HK>!%t0S
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