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)); 0)zJG |
} <H#0pFB
for(int i=0;i<nEndPos.length-1;i++) uF[*@N
{ Xe:rPxZf~
nEndPos = nStartPos[i+1]; V$FZVG/@#
} NB44GP1-@
nEndPos[nEndPos.length-1] = nFileLength; +BO kHXk1
} -awG14%
} pyX:$j2R+%
B[h^]k
unqUs08
//启动子线程 \N-3JOVy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; F+NX [
for(int i=0;i<nStartPos.length;i++) U8gj\G\`
{ 3mopTzs)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R'vNJDFY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !?).4yr
nStartPos,nEndPos,i); [+l6x1Am
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j(k%w
fileSplitterFetch.start(); Jqgm>\y
} 0;)Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), - q(a~Ge
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k;JDVRL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -{C Gn5]_#
nEndPos = " + nFileLength); t_16icF9U
// fileSplitterFetch[nPos.length-1].start(); +Q"~2_q5/;
bJ9*z~z)e
ai?N!RX%H
//等待子线程结束 O#):*II`9
//int count = 0; 8QL=%Pv
//是否结束while循环 HCkfw+gaV
boolean breakWhile = false; FG!hb?_1
z`$c4p6G6
#*w)rGkU2
while(!bStop) Ahbh,U
{ WI*CuJU<zJ
write_nPos(); Q {~$7J
Utility.sleep(500); m]}U!XT
breakWhile = true; =vQ J2Rg
lIx./Nf
KXl!VD,#`=
for(int i=0;i<nStartPos.length;i++) TF!v,cX
{ p_]b=3wt~
if(!fileSplitterFetch.bDownOver) -F*vN'
{ Pw +nO
breakWhile = false; [MKG5=kaE
break; Qm*ZOz'i
} ?* ,
} f9<"
if(breakWhile) \RPwSx
break; gs/ocu
z$d<ep{6
\o72VHG66
//count++; -&]!ig5v
//if(count>4) l\Ww^
// siteStop(); \/\w|j
} Olh{<~Fv
.L;e:cvx
@OFxnF`
System.err.println("文件下载结束！"); {J/Fp#
} a]%sks
catch(Exception e){e.printStackTrace ();} /NiD#s0t
} -])=\n!=
|6^%_kO!|
Z^'\()3t
//获得文件长度 F&7|`o3
public long getFileSize() -r3 s{HO
{ P,3w b
int nFileLength = -1; b5 NlL`g
try{ |#SZdXg
URL url = new URL(siteInfoBean.getSSiteURL()); v@M^ukk'}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $?k]KD
httpConnection.setRequestProperty("User-Agent","NetFox"); ZMiOKVl
D `V.gV]
1kUlQ*[<|
int responseCode=httpConnection.getResponseCode(); UuF(n$B
if(responseCode>=400) y:Of~ ]9@
{ Z_S{$D
processErrorCode(responseCode); Gky^S#
return -2; //-2 represent access is error nu~]9~)I
} $)8,dS
aH@-"Wi
R1w5,Zt
String sHeader; :{lP9%J-
B@6L<oZ
g*LD}`X/-
for(int i=1;;i++) -TG ="U
{ b8YdONdy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Fzt?M
//Utility.log(in.readLine()); )$df6sq
sHeader=httpConnection.getHeaderFieldKey(i); @@{5]Y
if(sHeader!=null) o59$vX,
{ m_Q&zp["
if(sHeader.equals("Content-Length")) _!, J iOI
{ c>>.>^5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1^= QIX
break; uZJfIC<>
} g|$;jQ\_
} h4F%lGot
else 3/Z>W|w#w
break; BL_0@<1X
} /T(9:1/G
} 7[u>#8
catch(IOException e){e.printStackTrace ();} 2u!&Te(!9
catch(Exception e){e.printStackTrace ();} rJCb8x+5a
gM=:80
!3mt<i]a"
Utility.log(nFileLength); #C?M-
sO6=w%l^
yrfV&C%=n
return nFileLength; S >CKm:7
} %Pt){9b
|m ?ZE:
fHH
//保存下载信息（文件指针位置） G\;6n
private void write_nPos() NY^0$h
{ i-5,*0e6m
try{ /"u37f?[^
output = new DataOutputStream(new FileOutputStream(tmpFile)); Rq[d\BN0.d
output.writeInt(nStartPos.length); ykPiZK
for(int i=0;i<nStartPos.length;i++) uh2_Rzln
{ C}Kl!
// output.writeLong(nPos); 7X/t2Vih@
output.writeLong(fileSplitterFetch.nStartPos); #+AQ:+
output.writeLong(fileSplitterFetch.nEndPos); $GGaR x
} y*-_
output.close(); lG94^|U
} A( vdlj
catch(IOException e){e.printStackTrace ();} +s"6[\H1d
catch(Exception e){e.printStackTrace ();} HBtk)
} \i%mokfbc
{A:uy
!%('8-x%
//读取保存的下载信息（文件指针位置） E BBd
private void read_nPos() xSK#ovH2
{ NE8W--Cg|
try{ @&WHX#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); q=BljSX
int nCount = input.readInt(); ` K{k0_{
nStartPos = new long[nCount]; }F_c0zM
nEndPos = new long[nCount]; /YF:WKr2
for(int i=0;i<nStartPos.length;i++) SFDTHvXu#_
{ 'EAskA]*
nStartPos = input.readLong(); Im/tU6ybV
nEndPos = input.readLong(); /+SLq`'u)
} D5?8`U m=
input.close(); Y6sX|~Zy
} S\&3t}_
catch(IOException e){e.printStackTrace ();} %sr- xE
catch(Exception e){e.printStackTrace ();} G,|!&=Pe|E
} }A24;'}
9T24dofkJ
LtMM89u
private void processErrorCode(int nErrorCode) bP9ly9FH
{ $P0q!
System.err.println("Error Code : " + nErrorCode); c!4F0(n4
} l_+@Xpl
x2#JD|0
3 J04 $cD
//停止文件下载 }:ZA)
public void siteStop() \{lv~I
{ iT4*~(p 3
bStop = true; vCaN[
for(int i=0;i<nStartPos.length;i++) UGhEaKH~R
fileSplitterFetch.splitterStop(); [c 8=b,EI
L#UR>Z#9
+ZOiL[rS
} chE!,gik
} hb5K"9Y
//负责部分文件的抓取 '|^:,@8P9
**FileSplitterFetch.java PWpt\g
*/ p1Zb&:+
package NetFox; ([u|j
XTJD>
\7/yWd{N$
import java.io.*; U+)p'%f;
import java.net.*; 'Be'!9K*d
`)n4I:)2
Pj-INc96
public class FileSplitterFetch extends Thread { :/;/mHG]
EE!}$qOR
d7X&3L%Oq
String sURL; //File URL K}R+~<bIY
long nStartPos; //File Snippet Start Position p%"dYH%]&0
long nEndPos; //File Snippet End Position PX 8UVA
int nThreadID; //Thread's ID r<e%;S
boolean bDownOver = false; //Downing is over 5XZ!yYB?
boolean bStop = false; //Stop identical oY18a*_>M1
FileAccessI fileAccessI = null; //File Access interface }p7iv:P=3
Mn.,?IF`K
(hzN(Dh
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ump~)?_B
{ KeQcL4<
this.sURL = sURL; YZBh}l6t
this.nStartPos = nStart; kW g.-$pp
this.nEndPos = nEnd; 3`HK^((o
nThreadID = id; @0?!bua_|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 my.EvN
} u#E'k KGO
\WCQ>c?~
v~P,OP("c
public void run() o|(5Sr&H
{ %X{EupiFA
while(nStartPos < nEndPos && !bStop) @Iv;y*y
{ $RPW/Lyiq
}~XWtWbd-
V0\[|E;F
try{ \n)',4mY
URL url = new URL(sURL); JQ&t"`\k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6Dq4Q|C
httpConnection.setRequestProperty("User-Agent","NetFox"); #.bW9j/
String sProperty = "bytes="+nStartPos+"-"; $"^K~5Q
httpConnection.setRequestProperty("RANGE",sProperty); qos7u91z
Utility.log(sProperty); u*l|MIi6J
L_8zZ8 o
Z'JS@dV
InputStream input = httpConnection.getInputStream(); B[t^u\Fk
//logResponseHead(httpConnection); TC\+>LXiZ
9t"Rw ns
?['!0PF
byte[] b = new byte[1024]; }vd*eexA
int nRead; SiratkP9n7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RdTM5ANT
{ i--t ?@#
nStartPos += fileAccessI.write(b,0,nRead); ut{T:kT
//if(nThreadID == 1) j9+$hu#a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >gk_klLh
} +2~kHrv
,kN;d}bg
#<im?
Utility.log("Thread " + nThreadID + " is over!"); ETe4I`d{
bDownOver = true; !_<6}:ZB
//nPos = fileAccessI.write (b,0,nRead); %qP[+N&
} 7RAB"T;?Q
catch(Exception e){e.printStackTrace ();} J-F".6i5
} QHEtG2
} ~Iu!B Y
^:eZpQ [,
;;Q^/rkC
//打印回应的头信息 )O]T}eI
public void logResponseHead(HttpURLConnection con) @;Ttdwg#J
{ 6o3 bq|
for(int i=1;;i++) mPV<a&U
{ kSQ8kU_w+
String header=con.getHeaderFieldKey(i); '|C3t!H`
if(header!=null) ly[LF1t
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E$e7(D
Utility.log(header+" : "+con.getHeaderField(header)); ~4S$+*'8
else rz?Cn X.t
break; *Gbhk8}V'
} RpHlq
} }'X=&3m
hvd}l8
Y::0v@&(
public void splitterStop() H"C'<(4*\
{ ]n22+]D
bStop = true; _"DS?`z6
} 4`IM[DIG~
w2)Ro:G
ou|emAV
} DX>a0-Xj
L[` l80
Qw5nfg3T
/* Wgq|Q*
**FileAccess.java OG,P"sv
*//文件访问(定位，写) sGvbL-S-f:
package NetFox; `&$8/_`
import java.io.*; ${+u-Wfau
c8qr-x1HG
[M_{~1xX
public class FileAccessI implements Serializable{ h6 \P&Z
<#63tN9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 THA9OXP
RandomAccessFile oSavedFile; hGRj
long nPos; XC4Z,,ah"
QFyL2Xes/
mCtS_"W
public FileAccessI() throws IOException YdY-Jg Xm
{ )&DAbB!O
this("",0); h`fVQN.3
} CUA @CZ6{
}2A6W%^>]
/'O8RUjN
public FileAccessI(String sName,long nPos) throws IOException ^ k^y|\UtZ
{ 97}]@xN=
oSavedFile = new RandomAccessFile(sName,"rw"); $EMOz=)I#
this.nPos = nPos; !,J# r
oSavedFile.seek(nPos); 73WSW/^F
} H#-3
I-7LT?r
.b:!qUE^
public synchronized int write(byte[] b,int nStart,int nLen) $|4C]Me (
{ l?Y^3x}j
int n = -1; `sxfj)s
try{ uFd$*`jS
oSavedFile.write(b,nStart,nLen); q^@*{H
n = nLen; ]`E+HLEQ'
} D-3[#~MV
catch(IOException e) |Td+,>,
{ 4DXbeQs:
e.printStackTrace (); CU$khz"
} ijI/z5
k15vs
)fH Q7
return n; -!\3;/
} \?:L>-&h8
-@uFRQt
b^Hrzn
} idmU.`
QbU5FPiN
B( [x8A]
/* yTaMlT|
**SiteInfoBean.java -H1=N
*/ @WJ;T= L
package NetFox; oL4W>b )
@|!4X(2
|J`EM7qMK
public class SiteInfoBean { TyxIlI4"
:-&|QVH
?-??>& z
private String sSiteURL; //Site's URL .@dC]$2=
private String sFilePath; //Saved File's Path 61\u{@o$
private String sFileName; //Saved File's Name f*ZU a
private int nSplitter; //Count of Splited Downloading File Z1Qz LvWs
1CtUf7 `/Q
^({)t
public SiteInfoBean() wAMg"ImJ
{//nSplitter的缺省值为5 (su,=Z
//default value of nSplitter is 5 " T(hcI
this("","","",5); ?}||?2=P
} SNEhP5!
c0Ug5Vr
gW,[X(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <Ij!x`MS+
{ J )1
sSiteURL= sURL; dzcF15H1
sFilePath = sPath; ;!yK~OBxt
sFileName = sName; 2:+8]b3i
this.nSplitter = nSpiltter; *[MWvs:,
w+o5iPLX
|5@Ra@0
} lED!}h'4
M8^ID #
3CUQQ_
public String getSSiteURL() I-v} DuM
{ 3F9V,zWtTi
return sSiteURL; 6)HmE[[F
} D)*
O5dS$[`j\p
<H[w0Z$
public void setSSiteURL(String value) \u=d`}E
{ ;qx#]Z0 <
sSiteURL = value; Rq4;{a/j
} x"r0<RK
u ExLj6
T+8Yd(:hX
public String getSFilePath() ,n|si#
{ <y 4(!z"
return sFilePath; `RTxc
} tZxx#v`
-oD,F $Rb
Bz+oMN#XJ
public void setSFilePath(String value) gqaM<!]
{ u#05`i:Z
sFilePath = value; !_glZ*tL
} Q+CJd>B
; :e7Z^\/k
! FcGa
public String getSFileName() KbJ6U75|f
{ ^0,}y]5p
return sFileName; aRd~T6I
} 6]4~]!
+cpb!YEAb
1nVQYqT_
public void setSFileName(String value) 2g(_Kdj*{
{ qLR;:$]Q&8
sFileName = value; +in)(a.
} ?pL|eS7
+Z#=z,.^
K5>3
public int getNSplitter() eAHY/Y!
{ 5!0iK9O
return nSplitter; /08FV|tX)
} ;H$Cq' I
D2e-b
yoE-a
public void setNSplitter(int nCount) z:'m50'
{ D@=]mh6vl
nSplitter = nCount; ~tUZQ5"
} L K&c~ Uy
} j/v>,MM
P0N/bp2Uy
/Qgb t
/* :kZ]Swi 5
**Utility.java *h^->+0n
*/ lM-\:Q!
package NetFox; m:_#kfC&K"
v[CR$@Y
qxRsq&_
public class Utility { \Z*:l(
jAQ{H
zK0M WyXO
public Utility() 92-Xz6Bo9
{ $W._FAAJ#
-e_fn&2,Y
&{)<Q(g
} 1q}32^>+o
hB?#b`i^
//线程睡眠 ;NP-tA)
public static void sleep(int nSecond) 0jp].''RK\
{ AArLNXzVW
try{ DpHubqWz
Thread.sleep(nSecond); LP3#f{U
} >^8O:.
catch(Exception e) kV-<[5AWW
{ Z<U,]iZB
e.printStackTrace (); 8~y!X0Ov!
} R ENCk(
} [gzaOP`f
bbL\xq^
//日志 =i~ = |K!
public static void log(String sMsg) @= <{_p
{ l,n_G/\
System.err.println(sMsg); Vmz#u1gGT6
} y)r`<B
o*T?f)_[p
.M6.]H
public static void log(int sMsg) b~;:[ #
{ I!zoo[/)%
System.err.println(sMsg); x1=`Z@^
} U<6)CW1;
} GzEw~JAs
-=-^rQx9
sBlq)h;G?6
/* lh-.I]>&`
**TestMethod.java Vy&X1lG:
*/ Ehy(;n)\
package NetFox; TF%n1H-sF
c((3B
(JU8F-/9
public class TestMethod { lU 9o"2
\^1^|a"
nS#F*)
public TestMethod() oy[s])Tg
{ ///xx/weblogic60b2_win.exe e_-g|ukC
try{ ]W3u~T*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); df{?E):
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Eu|/pH=:
SiteFileFetch fileFetch = new SiteFileFetch(bean); fMwF|;
fileFetch.start(); lB}?ey
} s.(.OXD&
catch(Exception e){e.printStackTrace ();} y9}qB:[bR
f y|JE9Io_
4n#u?)
} H Qj,0#J)
y^r'4zN'
X&Oo[Z
public static void main(String[] args) u`EK^\R
{ o.$48h(
new TestMethod(); .p{lzI9
} eg~ Dm>Es
} y0O(n/
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