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)); Wn=sF,c
} |&=-Nm
for(int i=0;i<nEndPos.length-1;i++) <l5i%?
{ =8T!ldVxES
nEndPos = nStartPos[i+1]; 6]?%1HSi
} v]V N'Hs?
nEndPos[nEndPos.length-1] = nFileLength; k\#;
} RJWO h
} w1)TnGT
2L](4Q[M
GM%OO)dO}
//启动子线程 y8~OkdlN#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SCcvU4`o
for(int i=0;i<nStartPos.length;i++) \ZLi Y
{ :0l+x0l}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *2X~NJCt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3 ,>M-F
nStartPos,nEndPos,i); $os]$5(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;Sivu-%
fileSplitterFetch.start(); %1Q:{m
} 0A)0Zw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V8M()7uJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Qfm$q~`D^W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^Lgvey%
nEndPos = " + nFileLength); e-ta7R4
// fileSplitterFetch[nPos.length-1].start(); -"I$$C
jhm3:;Z
Qfn:5B]tI
//等待子线程结束 <!sLfz?
//int count = 0; @Ul3J )=m
//是否结束while循环 <YU?1y?V
boolean breakWhile = false; $t;:"i>
r1r$y2v~
.]vb\NBK7
while(!bStop) 3}H{4]*%_
{ ;_bRq:!j;
write_nPos(); Uqel UL}
Utility.sleep(500); zzf@U&x<
breakWhile = true; E#KZZ lbx
'."_TEIF
jKml:)k
for(int i=0;i<nStartPos.length;i++) ?kO.>o
{ g5nJ0=9
if(!fileSplitterFetch.bDownOver) +LRKS
{ 0/)2RmF
breakWhile = false; -iR2UE@M
break; dC({B3#e{
} qf x*a88
} 5IF5R#
if(breakWhile) PGP#$JC
break; O6G\0o
I<D#
K ";Et
//count++; ;g!rc#z2g
//if(count>4) dkw.o.e
// siteStop(); aoey 5hts
} GmB&TDm
bh.&vp.kP
UOZ+&DL,L
System.err.println("文件下载结束！"); EQ$k^Y8 "
} [q?RJmB]
catch(Exception e){e.printStackTrace ();} c*ueI5i
} 8 MO-QO
+F)-n2Bi
./F:]/Mt
//获得文件长度 /2? CB\
public long getFileSize() [on_=N{W[
{ V5K/)\#
int nFileLength = -1; t%Jk3W/f
try{ kGV:=h
URL url = new URL(siteInfoBean.getSSiteURL()); N#ggT9>X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i3w~&y-
httpConnection.setRequestProperty("User-Agent","NetFox"); ^{uHph9ny
QJ XP-
<<0sv9qw1
int responseCode=httpConnection.getResponseCode(); \\k=N(n
if(responseCode>=400) <Z%=lwtX
{ ,\6Vb*G|E>
processErrorCode(responseCode); 712nD ?>
return -2; //-2 represent access is error P2'N4?2
} (mIjG)4t
p]mN)
j0e,>X8
String sHeader; kkjugm{D7
2=_$&oT**
Z^|N]Ej
for(int i=1;;i++) ~X3g_<b_8
{ F}}!e.>c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $2a"Ec!7
//Utility.log(in.readLine()); tDRR3=9pX
sHeader=httpConnection.getHeaderFieldKey(i); ]6e(-v!U
if(sHeader!=null) BH0m[9nU;
{ 76tn`4NIP
if(sHeader.equals("Content-Length")) eUy*0
{ %R>n5m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1Vu#:6%
break; ,-Hj
} "Pwa}{
} 5GM-*Ak@
else wyy 1M+
break; K83'`W^
} HV~Fe!J_
} 9O 'j+?(`@
catch(IOException e){e.printStackTrace ();} 8oJl ]
catch(Exception e){e.printStackTrace ();} [#Qf#T%5h
;U=b6xE
o-rX4=T
Utility.log(nFileLength); bG]0|
1d< b\P0
?y?9;;
return nFileLength; I!L J&>
} H7Q$k4\l
/9pxEidVAS
1b%Oi.;
//保存下载信息（文件指针位置） (I~
private void write_nPos() n[Q(q[ULV
{ ]VjvG};
try{ dx@dnWRT,
output = new DataOutputStream(new FileOutputStream(tmpFile)); &G"s!:
output.writeInt(nStartPos.length); G!Brt&_'
for(int i=0;i<nStartPos.length;i++) 3Q$4`p;
{ ;5ki$)v"
// output.writeLong(nPos); =Ydrct
output.writeLong(fileSplitterFetch.nStartPos); >=0]7k;
output.writeLong(fileSplitterFetch.nEndPos); gML8lu0)
} gxl7jY
output.close(); $E@n;0P
} E<jajYj
catch(IOException e){e.printStackTrace ();} Lng. X8D
catch(Exception e){e.printStackTrace ();} GNJ/|9
} ;}E}N:A
NF&Sv
~LS</_N
//读取保存的下载信息（文件指针位置） iE''>Z
private void read_nPos() RB %+|@c
{ t1w]L
try{ +;~N; BT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -zFJ)!/?
int nCount = input.readInt(); 6Hnez@d
nStartPos = new long[nCount]; Dz0D ^(;V
nEndPos = new long[nCount]; !`e`4y*N
for(int i=0;i<nStartPos.length;i++) 5!?5S$>
{ e6taQz@}
nStartPos = input.readLong(); "B{3q`(
nEndPos = input.readLong(); Onq^|r's&
} `PbY(6CF
input.close(); Z+v,o1
} `^[k8Z(
catch(IOException e){e.printStackTrace ();} oJ4HvrUO
catch(Exception e){e.printStackTrace ();} tY;<S}[@7w
} 0I.KHIBk
a]r+np]vTy
t)&U'^
private void processErrorCode(int nErrorCode) 3Z";a
{ o4" [{LyT
System.err.println("Error Code : " + nErrorCode); 1L!;lP2
} <mFDC?j
m+!.H\
J!l/.:`6
//停止文件下载 DT`HS/~fH
public void siteStop() ;}SGJ7
{ Ye3o}G9z
bStop = true; q? ">
for(int i=0;i<nStartPos.length;i++) bh@CtnO
fileSplitterFetch.splitterStop(); 9I/l+IS"X
Es+I]o0K
(?Mn_FNE|
} 1L*[!QT4
} ]`)5 Qe4
//负责部分文件的抓取 &?R/6"J
**FileSplitterFetch.java &ww-t..
*/ xfeED^?
package NetFox; W\~ie}D{
*F1TZ_GS
\}Am]Y/ w
import java.io.*; ^UKAD'_#%O
import java.net.*; 684& H8
_]zX W
ycBgr,Ynu<
public class FileSplitterFetch extends Thread { 3JGrJ!x
D\_nqx9O
v;\cM/&5
String sURL; //File URL BI?, 3
long nStartPos; //File Snippet Start Position G[ U5R?/
long nEndPos; //File Snippet End Position R>0[w$
int nThreadID; //Thread's ID SEM?vQ 0"}
boolean bDownOver = false; //Downing is over d` ttWWPw
boolean bStop = false; //Stop identical h,$CJdDY]
FileAccessI fileAccessI = null; //File Access interface %e]G]B%
HDV-qYD|O~
R5ra*!|L)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~2k.x*$
{ rNk'W,FU
this.sURL = sURL; #r#[&b
this.nStartPos = nStart; ]jD\4\M}
this.nEndPos = nEnd; 1Rd|P<y
nThreadID = id; -rU_bnm
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \OVFZ D
} Z5'^81m$o
NWn*_@7;
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public void run() f,yl'2{
{ dE"_gwtX
while(nStartPos < nEndPos && !bStop) uaO.7QSwN
{ w8X5kk
y-26\eY^P
@.7/lRr@bp
try{ [p6:uNo
URL url = new URL(sURL); ]B )nN':
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c?CD;Pk
httpConnection.setRequestProperty("User-Agent","NetFox"); >>T7;[h
String sProperty = "bytes="+nStartPos+"-"; jVnTpa!A
httpConnection.setRequestProperty("RANGE",sProperty); 8vuTF*{yZ
Utility.log(sProperty); O(I^:_eH
Xr K29a
:O413#8
InputStream input = httpConnection.getInputStream(); WkiT,(i
//logResponseHead(httpConnection); 6agq^wI
=W7-;&
gfK_g)'2U
byte[] b = new byte[1024]; +\Vw:~e
int nRead; :j`f%Vg~x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h"ZIh= j@
{ `R2Iw I&
nStartPos += fileAccessI.write(b,0,nRead); >s5}pkAv|e
//if(nThreadID == 1) =J1V?x=l@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pK-tj
} z@VL?A(3
x[lIib1s
_6fy'%J=U
Utility.log("Thread " + nThreadID + " is over!"); ^5s7mls
bDownOver = true; `n>|rd
//nPos = fileAccessI.write (b,0,nRead); \'Ca1[y@B
} sAc1t`
catch(Exception e){e.printStackTrace ();} R*pPUw\yn
} KS8@A/f
} i@+m<YS:2>
)tBz=hy#
_p8u &TZ
//打印回应的头信息 +A8q.-N G
public void logResponseHead(HttpURLConnection con) .T7CMkYt
{ zd%f5L('
for(int i=1;;i++) iYBc4'X
{ c/+6M
String header=con.getHeaderFieldKey(i); )K?7(H/j
if(header!=null) 02Vfg42
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a2.6S./
Utility.log(header+" : "+con.getHeaderField(header)); LC]0c)v#
else ?Ojv<L-f.:
break; G%HG6
} }~W/NP_F
} L91vp'+2
f#&z m} t
}6^5mhsL
public void splitterStop() N & b3cV
{ y]t19G+
bStop = true; JRC2+BU /
} w=fWW^>bP
<B>qEa_I
>bWpj8Kv
} FNUs .d"
%P~;>4i,
|aenQA#
/* JYWoQ[ZO#>
**FileAccess.java Q
*//文件访问(定位，写) W#U|;@"
package NetFox; p^ (Z
import java.io.*; w#)u+^-
T(u;<}e@[
lZRO"[<
public class FileAccessI implements Serializable{ 3U^Vz9LW
j~Pwt9G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [<,7LG<
RandomAccessFile oSavedFile; DX!dU'tj
long nPos; Ra53M!>]
Fy\q>(v.
Eb~vNdPo
public FileAccessI() throws IOException Ag2~q
{ *bo| F%NAz
this("",0); _*UI}JtlS
} B?&0NpVD
W#!AZ!
WYF8?1dt +
public FileAccessI(String sName,long nPos) throws IOException FR6 W-L
{ .WKJ37od
oSavedFile = new RandomAccessFile(sName,"rw"); 9nVb$pfe#
this.nPos = nPos; /[lEZ['^
oSavedFile.seek(nPos); %Qz<Lk">.
} J>#hu3&UOQ
9b >+ehjB
]h1.1@>xc
public synchronized int write(byte[] b,int nStart,int nLen) !i8)si_
{ qN1fWU#$
int n = -1; &I=o1F2B)
try{ i/*)1;xsk
oSavedFile.write(b,nStart,nLen); Vaf,
n = nLen; syLdm3d|
} <gi~:%T
catch(IOException e) :Ni#XZ{F-/
{ cQ<|Of
e.printStackTrace (); 9Vq
} ;UXV!8SM
h8O\sKn
u(3 uZ:
return n; XK\nOHLS
} rb@[Edj
l'4<^q
>Z*b0j
} ZDaHR-%Y
d)U(XiK'
| eCVq(R
/* UTE6U6
**SiteInfoBean.java 4jDi3MMU9
*/ [Y!HQ9^LEp
package NetFox; XM5)|D
(PH7nW7
W=EcbH9/.)
public class SiteInfoBean { 5Q%)|(U'
U"|1@W#
uQbag]&j
private String sSiteURL; //Site's URL ;;i419
private String sFilePath; //Saved File's Path m$W2E.-$'#
private String sFileName; //Saved File's Name zQ:nL*X'Z"
private int nSplitter; //Count of Splited Downloading File &a'mG=(K_c
!BW!!/U
qF^P\cD
public SiteInfoBean() HOu$14g
{//nSplitter的缺省值为5 h #gI1(uL
//default value of nSplitter is 5 +C;;4s)
this("","","",5); [4C_iaE
} 2k=|p@V n~
Has}oe[
}R}M>^(R4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6oQ7u90z*
{ y`$qcEw
sSiteURL= sURL; 'LG\]h>+)
sFilePath = sPath; sF)$<[w
sFileName = sName; IAkQR0fcN
this.nSplitter = nSpiltter; 0TV16--
TDfloDxA
`qd5+~c
} m Qx1co
{?^ES*5
7hx^U90K
public String getSSiteURL() F$4=7Njv
{ h&i(Kfv*
return sSiteURL; q1YNp`]0i8
} +%[, m&
*`qI<]!
/g*_dH)=
public void setSSiteURL(String value) Ux?G:LLz
{ D1deh=
sSiteURL = value; ?>ZrdfTwz,
} 7>@0nHec
20$Tky_
ik?IC$*n3i
public String getSFilePath() ^y ', l
{ Ow1+zltgj-
return sFilePath; BQUYT/$(
} a'-xCV|^
r UZN$="N
?nu<)~r53
public void setSFilePath(String value) J R~s`>2
{ h8p{
sFilePath = value; Xo(W\Pes
} jQz^)8)B
HL[V}m
S.iUiS"
public String getSFileName() `ba<eT':
{ >op/<?<
return sFileName; NR&a er
} X`v6gv5qj
(/&ht-~EL
@o@SU"[?_
public void setSFileName(String value) SK/}bZ;f
{ t3}_mJ
sFileName = value; #,lbM%a
} \QSD*
8Dxg6>
( Ygy%O%
public int getNSplitter() *3RD\.jPX
{ SmyJ@.L"
return nSplitter; { ~{D(k
} #0*I|gfV
n|=yw6aV'
b!SIs*
public void setNSplitter(int nCount) "/^kFsvp
{ 2&s(:=
nSplitter = nCount; T|oDJ]\J
} /YwwG;1
} 26zif
%^I 7=
,-$%>Uv
/* NJ}xqg
**Utility.java uY3$nlhP6
*/ 1Ogtzf
package NetFox; ByWad@-6i
tx3p, X
;F,6]LH!
public class Utility { -jTK3&5
_mQ~[}y+?
k ;vOPcw
public Utility() [daR)C
{ LWM& k#i
86&r;c:
R*dXbI&,e
} Ax!@vL&@
rA_r$X
//线程睡眠 hoPh#? G
public static void sleep(int nSecond) V^9%+L+E5
{ ~te{9/
try{ /oM&29 jy
Thread.sleep(nSecond); ~fgS"F^7n
} ,tBc%&.f
catch(Exception e) +x:VIi
{ WIwGw%_~
e.printStackTrace (); c3Ig4n0Y>
} gd31ds!G
} a 6fH*2E
[nsTO5G$u
//日志 [S`Fm>,
public static void log(String sMsg) h2]GV-
{ l`K5fk
System.err.println(sMsg); ^&c|z35F
} P/9|mYmsq
!G~\9
#DTBdBh?I
public static void log(int sMsg) EX3;|z@5;
{ 'aZAWY d
System.err.println(sMsg); 97!VH>MX
} BS3BJwf; f
} T:j!a{_|
pHDPj,lu
uUpOa+t
/* ~65lDFY/
**TestMethod.java `p^xdj}
*/ `jFvG\aC
package NetFox; a<D]Gz^h
[;INVUwG^
MES|iB
public class TestMethod { I1Gk^wO
;{>-K8=>$
b WZX
public TestMethod() vC5 (
{ ///xx/weblogic60b2_win.exe e-{4qt
try{ BA0.B0+"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V:4($
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kmL~H1qd
SiteFileFetch fileFetch = new SiteFileFetch(bean); Vuo 8[h>
fileFetch.start(); {[B`q
} iuq%Q\0@w
catch(Exception e){e.printStackTrace ();} b{JxTT}03
Sh5SOYLz
laFF/g;sRC
} h|=&a0
J 9k~cz
! XNTk]!
public static void main(String[] args) h5#V,$
{ le`_
new TestMethod(); gI~jf- w
} $3n@2 N`
} (kI@U![u
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