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)); 9Y:I)^ek
} 3x+lf4"
for(int i=0;i<nEndPos.length-1;i++) 0Qt!w(
{ E)_n?>Ar
nEndPos = nStartPos[i+1]; } {1IB
} 6Rn?pe^
nEndPos[nEndPos.length-1] = nFileLength; 4E^ ?}_$
} H0afu)$,
} gXdMGO>
0~qc,-)3
/mex{+p>tO
//启动子线程 F06o-xH=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #DUfEZ
for(int i=0;i<nStartPos.length;i++) eP-|3$
{ |UXSUP @s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +F8{4^w1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z{rV|vQ
nStartPos,nEndPos,i); -#|;qFD]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l)%PvLbL
fileSplitterFetch.start(); DhyR
} Z3S+")^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >O-KJZ'GV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'C'mgEl%L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zXY8:+f
nEndPos = " + nFileLength); ZyGoOk
// fileSplitterFetch[nPos.length-1].start(); [:y:_ECs6
T8o](:B~
B)JMughq_
//等待子线程结束 JQ03om--(
//int count = 0; :wC\IwG~CE
//是否结束while循环 :0J`4
boolean breakWhile = false; >(Y CZ
;qWu8\T+
su%(!XJQpg
while(!bStop) Z2g'&,uc#
{ |.N[NY
write_nPos(); Bh3F4k2bg7
Utility.sleep(500); }>@\I^Xm,
breakWhile = true; !Km[Qw k-
eYUb>M)
V]zc-gYI
for(int i=0;i<nStartPos.length;i++) dCd~]CI
{ <\&9Odqc
if(!fileSplitterFetch.bDownOver) TR DQ+Z
{ *S,~zOYN
breakWhile = false; lfgJQzi G
break; lz,M$HG<[
} xi5"?*&Sb
} <V&0GAZ
if(breakWhile) +{:uPY#1
break; {kpF etXt?
_SBbd9
Z1HH0{q-A
//count++; 4IeCb?
//if(count>4) l f>/
// siteStop(); k =! Q
} {MgRi7
xKUL}>8
2%%\jlT_
System.err.println("文件下载结束！"); =]7o+L4
} p!UR;xHI\
catch(Exception e){e.printStackTrace ();} rwP#Yj[BK+
} I"Zp^j
K<>kT4
e5'I W__
//获得文件长度 h4;kjr}h}
public long getFileSize() jK w 96
{ G2`z?);1b
int nFileLength = -1; ~5KcbGD~
try{ `c
URL url = new URL(siteInfoBean.getSSiteURL()); y!FO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k\f _\pj6
httpConnection.setRequestProperty("User-Agent","NetFox"); meX2Y;
J2z/XHS
%qc_kQ5%
int responseCode=httpConnection.getResponseCode(); 6 s=VU\
if(responseCode>=400) 9!( 8o
{ n5}]C{s'
processErrorCode(responseCode); OC=&!<
return -2; //-2 represent access is error d(q1?{zr4
} p@tg pFt
*[si!e%
p'jc=bL E
String sHeader; =5|7S&{
p<fCGU
TLwxP"
for(int i=1;;i++) RjWwsC~B
{ Q %o@s3~O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tsb[=W!Ar8
//Utility.log(in.readLine()); :iE b^F}
sHeader=httpConnection.getHeaderFieldKey(i); `ASDUgx Mq
if(sHeader!=null) JK/{IkF
{ :;{M0
if(sHeader.equals("Content-Length")) As,`($=
{ 6v)TCj/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SQN?[v
break; rpow@@ad<
} xw#CwMbbi
} ?ko#N?hgI
else H*W>v[>
break; 2zC4nF)>O
} Ta?J;&<u]/
} (?4%Xtul1
catch(IOException e){e.printStackTrace ();} m{q'RAw
catch(Exception e){e.printStackTrace ();} (:l6R9'=
5JzvT JMx
n>'(d*[e&
Utility.log(nFileLength); eRMN=qP.q
^j}C]cq{Xg
F-m%d@P&X
return nFileLength; !rnjmc
} F6\{gQ<E
d( v"{N}
Q|_F P:
//保存下载信息（文件指针位置） ~]KdsT(=_
private void write_nPos() k|;a"56F
{ JxVGzb`8
try{ Vl_6nY;
output = new DataOutputStream(new FileOutputStream(tmpFile)); gFaZ ._
output.writeInt(nStartPos.length); D$ds[if$U,
for(int i=0;i<nStartPos.length;i++) 7H Har'=T
{ u BEwYQB
// output.writeLong(nPos); qDdO-fPev
output.writeLong(fileSplitterFetch.nStartPos); F-,gj{s
output.writeLong(fileSplitterFetch.nEndPos); khy'Y&\F;
} NW\CEJV
output.close(); 5H3o?x
} w'@gzK
catch(IOException e){e.printStackTrace ();} Nv5^2^Sc=
catch(Exception e){e.printStackTrace ();} ~~>m
} !5*VBE\
p4VARAqi
I*rUe#$
//读取保存的下载信息（文件指针位置） kvbZx{s
private void read_nPos() !JCs'?A
{ 7By7F:[b
try{ ^Om}9rXw1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L( 6b2{"
int nCount = input.readInt(); !f~a3 {;j
nStartPos = new long[nCount]; R~g|w4a@sC
nEndPos = new long[nCount]; !gXxM,R
for(int i=0;i<nStartPos.length;i++) Q>1BOH1by
{ h#0n2o#
nStartPos = input.readLong(); j97+'AKX
nEndPos = input.readLong(); hUMG}<
} %1#\LRA(
input.close(); '{d_q6,%
} ,3:f4e\<
catch(IOException e){e.printStackTrace ();} SdH=1zBc
catch(Exception e){e.printStackTrace ();} s$fM,l:!
} 1Yb&E7j
NpVL;6?7T
k{*EoV[.$
private void processErrorCode(int nErrorCode) d@3DsE.{i
{ l,@>J9}Se
System.err.println("Error Code : " + nErrorCode); uaIAVBRcS
} 0,hs%x>v
U%vTmdOY
.tRm1&Qi
//停止文件下载 /?81Ypt
public void siteStop() ;.h /D4
{ |V34;}\4
bStop = true; n.+*_c8k
for(int i=0;i<nStartPos.length;i++) @<W` w
fileSplitterFetch.splitterStop(); Iy)1(upM
Jh+;+"
24wDnDyh
} pm O9mWq
} Bl\:YYd
//负责部分文件的抓取 vQ< ~-E
**FileSplitterFetch.java 7C|AiSH
*/ l!p`g>$&f
package NetFox; 7-S?RU]g
dDS{XR
Xqf\}p n
import java.io.*; ANm@$xO*
import java.net.*; eU"yF >6'
?+}Su'pv}
9a_P 9s3w
public class FileSplitterFetch extends Thread { Yc#Uu8f-
4X=VNORlU0
5*z>ez2YQ7
String sURL; //File URL Luao?;|U
long nStartPos; //File Snippet Start Position :hICe+2ca
long nEndPos; //File Snippet End Position "kApGNB
int nThreadID; //Thread's ID 8u*<GbKGI
boolean bDownOver = false; //Downing is over z83v J*.
boolean bStop = false; //Stop identical a?gF;AYk
FileAccessI fileAccessI = null; //File Access interface ~gX1n9_n
uyX %&r
?8 }pZ_j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aR2N,<Cp5
{ ~W@dF~r
this.sURL = sURL; OP!R>|
this.nStartPos = nStart; (aYu[ML
this.nEndPos = nEnd; ?e9tnk3
nThreadID = id; cyNE}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y1cL dQn
} $#V'm{Hh
z$&B7?
|5flvkid
public void run() s8 WB!x{t
{ Y%i<~"k
while(nStartPos < nEndPos && !bStop) 56C8)?
{ !$Uo$?gC
| V(sCF
M8H hjoo
try{ ]I*RuDv}
URL url = new URL(sURL); ]*NYuEgc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i&DbZ=n2
httpConnection.setRequestProperty("User-Agent","NetFox"); /3)\^Pof
String sProperty = "bytes="+nStartPos+"-"; FH}?QebSR
httpConnection.setRequestProperty("RANGE",sProperty); n1\$|[^6
Utility.log(sProperty); "I56l2dxd
>FE8CH!W&
")8l'^Mq2
InputStream input = httpConnection.getInputStream(); |-JG _i
//logResponseHead(httpConnection); )B]"""J
wXQu%F3
|ts0j/A]Pi
byte[] b = new byte[1024]; ]{=y8]7
int nRead; bB4FjC':
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2>jk@~Z1:u
{ 6zM:p/
nStartPos += fileAccessI.write(b,0,nRead); :[@rA;L
//if(nThreadID == 1) /J^dzvH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]2u
} tE0{ae
@*rMMy 4
Ht.P670
Utility.log("Thread " + nThreadID + " is over!"); B-g uz[v
bDownOver = true; fDYTupKXH
//nPos = fileAccessI.write (b,0,nRead); ]DnAW'm
} O#.YTTj
catch(Exception e){e.printStackTrace ();} =?|$}vDO[
} pbKmFweq
} v,n 8$,
:G6CWE
38sLyoG=i
//打印回应的头信息 =b66H]h?
public void logResponseHead(HttpURLConnection con) XrUI[ryE
{ .?:#<=1
for(int i=1;;i++) Q>L(=j2t
{ [%^0L~:
String header=con.getHeaderFieldKey(i); hV $Zr4'
if(header!=null) ";dS~(~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \asn^V@"zz
Utility.log(header+" : "+con.getHeaderField(header)); XR]bd
else ;):;H?WS|A
break; `Ku:%~$/
} NtGJpT4YX
} KxErWP%
hXFT(J=
p7AsNqEp
public void splitterStop() vcW(?4e
{ In4VS:dD
bStop = true; 7zzFM
} %KF I~Qk
b7hICO-w
pIR_2Eq
} 2r2:
n-K/dI
!>'A2V~F
/* 8nZ_.
**FileAccess.java <LZ#A@]71
*//文件访问(定位，写) "~ =O`5V
package NetFox; S?Cd,WxT
import java.io.*; m>Z3p7!N}
O-.G("
<:AA R2=
public class FileAccessI implements Serializable{ w3i74C&0
h>>~Bi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .Ao _cx
RandomAccessFile oSavedFile; ?6"U('y>n
long nPos; '-(Z.e~e
E4=D$hfq`
("(wap~<nD
public FileAccessI() throws IOException '=G6$O2
{ L_T+KaQCH
this("",0); |;:Kn*0/]
} :CqR1_n%
E<D^j^T
N[-$*F,:_
public FileAccessI(String sName,long nPos) throws IOException uo?R;fX26
{ KCpq<A%
oSavedFile = new RandomAccessFile(sName,"rw"); A;X3z-[[
this.nPos = nPos; KtJc9dnX
oSavedFile.seek(nPos); jHob{3
} Mi NEf
ouyZh0G
'h;qI&
public synchronized int write(byte[] b,int nStart,int nLen) D?dS/agA
{ Lo}T%0"G
int n = -1; rR^o
try{ G/~b(V;>
oSavedFile.write(b,nStart,nLen); ;Tk/}Od!VN
n = nLen; 6i+AJCkC
} Vxo?%Dj
catch(IOException e) daCkjDGl\
{ [T9]q8"
e.printStackTrace (); %qqCpg4
} ts@w9|
/F^ Jn_
n4B uM R
return n; ,Y| ;V
} G,+3(C
D'%M#S0
-`\n/"#X6i
} Wm}T=L`
s(Wys^[g
-|u yJh
/* nm_taER
**SiteInfoBean.java /?j kVy*"
*/ N2|NYDQs
package NetFox; yXIJeo"
j"Ew)6j
`c^">L
public class SiteInfoBean { K[?@nl?,z
?.-+U~
KbciRRf!k
private String sSiteURL; //Site's URL ,c`Wmp^AY
private String sFilePath; //Saved File's Path Gh6U<;V?*
private String sFileName; //Saved File's Name k|RY; 8_
private int nSplitter; //Count of Splited Downloading File "Q\b6 7Ch
wmX(%5vY^
,jW a&7
public SiteInfoBean() I\-M`^@
{//nSplitter的缺省值为5 (i\{hq/
//default value of nSplitter is 5 OrL4G `O
this("","","",5); :}q)]W
} M<=e~';H
(]?M=?0\
6cjCn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *q\>DE=7
{ f8UJ3vB
sSiteURL= sURL; jUZ$vyT
sFilePath = sPath; ;*+H&
sFileName = sName; !M)] 1Y
this.nSplitter = nSpiltter; uT=5zu
*aFh*-Sj2I
~$//4kES
} S|KUh|=Q
SY:ISzB}
NYKYj`K
public String getSSiteURL() ;gAL_/_
{ B7Zi|-F
return sSiteURL; +~:OUR*>
} CRiqY_gBf
e\-,e+
AuM}L&`i^
public void setSSiteURL(String value) 1fM`n5?"
{ j,9/eZRZ
sSiteURL = value; +BhJske
} S{)K_x
<gFisc/#r
&Cm]*$?
public String getSFilePath() "&`>+Yw
{ m;1/+qs0
return sFilePath; 9s7TLT k
} N9*QQ0
I\M }Dxpp
]Nssn\X7
public void setSFilePath(String value) ;bHS^
{ QX&Y6CC`]
sFilePath = value; @KHY8y7
} o!&+ _BKw
Vo.~1^
fo~*Bp()-E
public String getSFileName() WCk. K
{ C1l'<
return sFileName; OTAe#]#
} O:~J_Wwl!
MXDCOe~07
!I&,!$
public void setSFileName(String value) P1^|r}
{ 3xdJ<Lrq
sFileName = value; Q Wc^}#!!
} $-jj%kS
DvLwX1(l
+7AH|v8
public int getNSplitter() CY*GCkH
{ i{:iRUC#
return nSplitter; cF EO}
} YdIZikF#
19[!9ci
MZWv#;.]
public void setNSplitter(int nCount) j/NX
{ p&4n"hC
nSplitter = nCount; <5#2^(
} nz#eJ
} T-+ uQ3
'n\PS,[1R
Hr7pcz/#l
/* mb%U~Na
**Utility.java =}I=s@
*/ Aeo=m}C;
package NetFox; 9x8Vsd
%BT]h3dcSS
u~JR]T
public class Utility { a({N}ZDo
Ro `Xs.X
=1VZcLNt
public Utility() rQ2TPX<?a
{ !mB `FC
C?W}/r[
1{a4zGE?[
} qzO5p=}
suFk<^3
//线程睡眠 jffNA^e
public static void sleep(int nSecond) 3J/l>1[
{ )iK:BL*Nw
try{ cW"DDm g
Thread.sleep(nSecond); jP2#w{xq
} bC) <K/Q9
catch(Exception e) rce._w }
{ a"t~K
e.printStackTrace (); 4gVIuF*pS
} 4vvQ7e7
} R(8?9-w
ma<uXq
//日志 6R$Yh0%
public static void log(String sMsg) o-AF_N
{ ]$sb<o .a
System.err.println(sMsg); 3)2{c
} wf\7sz
p&)d]oV>
kd]CV7(7
public static void log(int sMsg) EgbH{)u
{ 7fSNF7/+
System.err.println(sMsg); 0L,!o[L*
} XJy.xI>;
} 0_Elxc
ukc 7Z OQ
Tow!5VAM
/* ~_F;>N~
**TestMethod.java T(]*jaB
*/ 0*oavY*
package NetFox; 02NVdpo[wU
ylS6D
guf*>qNr
public class TestMethod { )^"V}z t
Dfc% jWbA
2+C:Em0yI
public TestMethod() ;4GGXT++L
{ ///xx/weblogic60b2_win.exe f4F%\ "
try{ n6M#Xc'JA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s_+.xIZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F;kKn:XL
SiteFileFetch fileFetch = new SiteFileFetch(bean); )`ixT)
fileFetch.start(); VN\VTSZh?\
} rl$"~/ oz
catch(Exception e){e.printStackTrace ();} :O,r3O6
CF\wR;6k
ue@W@pj
} jt9- v-
U}k@%m,
oR,zr
public static void main(String[] args) _iEnS4$A8
{ ;volBfv
new TestMethod(); }; M@JMu,
} :=5X)10
} $/@ L
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