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)); @`B_Q v@
} S/eplz;
for(int i=0;i<nEndPos.length-1;i++) -0`n(`2
{ er BerbEEH
nEndPos = nStartPos[i+1]; { **W7\h
} *@@dO_%6
nEndPos[nEndPos.length-1] = nFileLength; "-:g.x*d
} j)ln"u0R^B
} "tJ[M
t}}Ti$$>
\O~/^ Y3U!
//启动子线程 #d<"Ub
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1\lZ&KX$i
for(int i=0;i<nStartPos.length;i++) .*"KCQGOgM
{ \TzBu?,v8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #:Q\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), QS4~":D/C
nStartPos,nEndPos,i); S~m8j|3K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nRX'J5Q m<
fileSplitterFetch.start(); (u@X5O(a
} NyC&j`d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TntTR"6aD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =_N$0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !w/fwOo
nEndPos = " + nFileLength); u!+;Iy7
// fileSplitterFetch[nPos.length-1].start(); o)b-fAd@$
S1~EJa5H
<f)T*E^5%
//等待子线程结束 'Zex/:QS
//int count = 0; sc-hO9~k
//是否结束while循环 !H)!b#_
boolean breakWhile = false; l*CCnqE
Z{ 9Io/
($UUgjv F
while(!bStop) >^,?0HP
{ gCRPaF6
write_nPos(); i;qij[W.z
Utility.sleep(500); u+6L>7t88I
breakWhile = true; D^s#pOZS
&>Z;>6J,
[\fwnS_1
for(int i=0;i<nStartPos.length;i++) vaVV1
{ g%ys|
if(!fileSplitterFetch.bDownOver) ~-sG&u>
{ e*I92
breakWhile = false; iW9
break; 5TeGdfu @
} rkdA4'66w
} QAl4w)F
if(breakWhile) 6N Ogi
break; bQN3\mvY
)L":I
&Wdi 5T8
//count++; !"E/6z2&(k
//if(count>4) 9G7Brs:
// siteStop(); Bz%wV-
} m9c`"!
$Dv5TUKw
9`H4"H>yG
System.err.println("文件下载结束！"); tblduiN
} ]70ZerQ~L
catch(Exception e){e.printStackTrace ();} &VCg`r-{~
} EKQ>hww8
)@tHS-Jf
-~_|ZnuM9
//获得文件长度 y>T>
public long getFileSize() s`v$r,N0
{ Tgla_sMb
int nFileLength = -1; MU '-
try{ ,@M<O!%Cs
URL url = new URL(siteInfoBean.getSSiteURL()); r/)ZKO,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <4zSh3
httpConnection.setRequestProperty("User-Agent","NetFox"); fceO|mSz_
qf@P9M
vwa*'C
int responseCode=httpConnection.getResponseCode(); j`Ek:
if(responseCode>=400) ]|K6Z>V
{ &?xtmg<d
processErrorCode(responseCode); qq?o^_^4
return -2; //-2 represent access is error aN,?a@B
} ^e$!19g
Gv#bd05X
2o1WXE %$
String sHeader; H_| re
KCp9P2kv.
x",ktE>9
for(int i=1;;i++) +T,A^(&t
{ b53s@7/mq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :}#j-ZCC"
//Utility.log(in.readLine()); xDS]k]/(T
sHeader=httpConnection.getHeaderFieldKey(i); Z@*!0~NH=4
if(sHeader!=null) 3'0Jn6(
{ tef>Py
if(sHeader.equals("Content-Length")) D=.Ob<m`Z
{ kf|J
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i]@k'2N
break; NweGK
} im)r4={ 9
} (WY9EJ<s,
else v:w^$]4
break; NMC0y|G
} V_ntS&2o
} =@hCc
catch(IOException e){e.printStackTrace ();} PJ<qqA`!
catch(Exception e){e.printStackTrace ();} 0pH$MkQ
XJwgh y?(
4L97UhLL
Utility.log(nFileLength); F~OQ'59!Pf
@`^Z5n.4
?s)6 YF
return nFileLength; -QBM^L
} ;K4uu<e\
6o(.zk`d
/t2H%#v{
//保存下载信息（文件指针位置） *Utx0Me
private void write_nPos() 2FO<Z %Y
{ (wxi!
try{ n!Y}D:6c6
output = new DataOutputStream(new FileOutputStream(tmpFile)); xbHI4A"Z
output.writeInt(nStartPos.length); X%B$*y5
for(int i=0;i<nStartPos.length;i++) e5;YY
{ +br' 2Pn
// output.writeLong(nPos); FlrYXau
output.writeLong(fileSplitterFetch.nStartPos); #e@[{s7
output.writeLong(fileSplitterFetch.nEndPos); 5'w&M{{9
} OCCC' k
output.close(); ^'+#BPo9@
} %@q2
catch(IOException e){e.printStackTrace ();} vkG%w;
catch(Exception e){e.printStackTrace ();} yWT1CID
} CC$rt2\e
g]BA/Dw
nT}i&t!q8@
//读取保存的下载信息（文件指针位置） 3.ShAL
private void read_nPos() v5?ct?q
{ P"@^BQ4
try{ TXs&*\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WqCj;Tj|
int nCount = input.readInt(); N_+D#Z.g
nStartPos = new long[nCount]; CEzdH!nP
nEndPos = new long[nCount]; f^IB:e#j;
for(int i=0;i<nStartPos.length;i++) ,u-9e4
{ ]'hel#L;l
nStartPos = input.readLong(); mGmZ}H'{
nEndPos = input.readLong(); "W9z>ezp
} ^![7X'!;pt
input.close(); ~~t>;
} !?~>f>js_l
catch(IOException e){e.printStackTrace ();} ] oh.w
catch(Exception e){e.printStackTrace ();} xfyUT^
} ?QXc,*=N
x.OCE`
t$W~X~//
private void processErrorCode(int nErrorCode) R%Y#vUmBV{
{ uqg#(ADy?R
System.err.println("Error Code : " + nErrorCode); lB Y"@N
} L~])?d
3\Ma)\>R\-
[Q=NGHB1/
//停止文件下载 K!MIA
public void siteStop() |tkhsQ-;
{ *j0kb"#
bStop = true; LYv$U;*+
for(int i=0;i<nStartPos.length;i++) hD5G\TR.
fileSplitterFetch.splitterStop(); mSu1/?PS
*&VqAc%qD
iEJY[P1
} (3>Z NTm
} f(o1J|U{
//负责部分文件的抓取 J|z>5Z
**FileSplitterFetch.java GukS=rC9
*/ +80yyn#
package NetFox; 2}^fhMS
j\Z/R1RcW
9. 7XRxR^
import java.io.*; )j[rm
import java.net.*; PafsO,i-
!}gC0dJ
rg^
public class FileSplitterFetch extends Thread { B.-1wZl
i!!1^DMrw
Nd"4*l;
String sURL; //File URL 85Hb~|0
long nStartPos; //File Snippet Start Position lQolE P.pc
long nEndPos; //File Snippet End Position zu~E}
int nThreadID; //Thread's ID wSMP^kG
boolean bDownOver = false; //Downing is over /5y*ZIq]e
boolean bStop = false; //Stop identical ]^63n/Twj
FileAccessI fileAccessI = null; //File Access interface 2sOV3~bB
vZQ'
uNV\_'9>Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p+;[i%`
{ QlHxdRK`.
this.sURL = sURL; =h4* ^NJ
this.nStartPos = nStart; l$_Yl&!q$
this.nEndPos = nEnd; 3O:gZRxK
nThreadID = id; N!fTt,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1qw*mV;W)_
} ]i3 1@O
_;Q1PgT
Xy>+r[$D:
public void run() '7!b#if
{ D-[`wCa,
while(nStartPos < nEndPos && !bStop) O<1qU M
{ V_&>0P{q
X$L9kZ
\Ami-<T
try{ MMpGI^x!-X
URL url = new URL(sURL); XkWO-L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0t-!6
httpConnection.setRequestProperty("User-Agent","NetFox"); @@,l0/
String sProperty = "bytes="+nStartPos+"-"; 1HF=,K+
httpConnection.setRequestProperty("RANGE",sProperty); g?'4G$M
Utility.log(sProperty); c:/H}2/C
bk**% ]
[_&\wHX
InputStream input = httpConnection.getInputStream(); )PRyDC-
//logResponseHead(httpConnection); c teUKK.|)
uHv9D%R
Hvn{aLa.
byte[] b = new byte[1024]; nH#|]gVI
int nRead; K&t+3O
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c({V[eGY
{ JO4rU- n
nStartPos += fileAccessI.write(b,0,nRead); Pw^lp'dO
//if(nThreadID == 1) ZR~ *Yofy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wz-#kH5?
} HbRDa
E6{|zF/3'
5AWIk,[
Utility.log("Thread " + nThreadID + " is over!"); 0$-N
bDownOver = true; cMCGaaLU
//nPos = fileAccessI.write (b,0,nRead); poqcoSL"}
} r.5}Q?
catch(Exception e){e.printStackTrace ();} _`/:gkZS
} zqaz1rt[
} =kp-[7
O<0G\sU
z9k3@\7
//打印回应的头信息 rKR2v(c
public void logResponseHead(HttpURLConnection con) !+;'kI2
{ X\r?g
for(int i=1;;i++) p nS{W \Q
{ >AT{\W!N
String header=con.getHeaderFieldKey(i); Fxu'(xa
if(header!=null) TwlrncK*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v'"0Ya
Utility.log(header+" : "+con.getHeaderField(header)); <p<J;@
else L#Mul&r3x0
break; YxEc(a"
} l .8@F
} 6dG:3n}
##gq{hgjb$
a&6e~E$K2
public void splitterStop() 9V]\,mD=
{ y#'|=0vTvP
bStop = true; V^a]@GK:
} qRXb9c
]-Z="YPY
_;] 3w
} X~DI d
SjT8eH #
3d qj:4[f
/* ,k*g`OTW
**FileAccess.java l2))StEm
*//文件访问(定位，写) WUQlAsme
package NetFox; YQyf:xJ
import java.io.*; _S43_hW
_b+=q:$/
JG%y_ Qy?K
public class FileAccessI implements Serializable{ '%@fW:r~
,O[HX?>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1}A1P&2>
RandomAccessFile oSavedFile; Bn83W4M
long nPos; sLGut7@Sg
#{]X<et
@`&kn;7T
public FileAccessI() throws IOException Xsvf@/]U
{ B'( /W@
this("",0); xn49[T
} 3cuVyf<v
c$.h]&~dN
H pHXt78
public FileAccessI(String sName,long nPos) throws IOException zJnF#G
{ 0v%ZKvSID
oSavedFile = new RandomAccessFile(sName,"rw"); 4ZY0!'be-R
this.nPos = nPos; n\f8%z
oSavedFile.seek(nPos); $F|3VQ~
} xEt".K
={[s)G
VKcO]_W1
public synchronized int write(byte[] b,int nStart,int nLen) Mqu>#lL
{ q*,g
int n = -1; "0JG96&\
try{ %F'*0<
oSavedFile.write(b,nStart,nLen); 7^}np^[HB
n = nLen; K3QE>@']
} 0Q^a*7w`8a
catch(IOException e) x7qVLpcL3z
{ }@ Nurs)%_
e.printStackTrace (); b5kw*h+/'h
} C?v_ig
N=e-"8
dg9 DBn#
return n; 8lAs~c
} gOkq>i_
jmgU'w-s
*>x~`
} E'|@hL-jn
$is|B9B
+8tdAw
/* 35}{dr
**SiteInfoBean.java ?T+Uu
*/ bVEt?E*+
package NetFox; +}IOTw"O`
7_,)"J2^
[nQ<pTg~r
public class SiteInfoBean { 8*sZ/N.
4a'GWzUtS
xHs8']*\
private String sSiteURL; //Site's URL <I}O_:%
private String sFilePath; //Saved File's Path <k2Qcicy
private String sFileName; //Saved File's Name p&Usl.
private int nSplitter; //Count of Splited Downloading File EZ+_*_9
iqCZIahf
,j{$SuZM
public SiteInfoBean() lM1Y }
{//nSplitter的缺省值为5 Jh3(5d"MV
//default value of nSplitter is 5 F8(6P1}E
this("","","",5); -p|@Enn
} P I gbeP
2Z3c`/k
F-MN%WD~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *ujn+0)[
{ *,w9#?2x
sSiteURL= sURL; wyqXD.of
sFilePath = sPath; S`yY<1[O
sFileName = sName; p4k*vuu>
this.nSplitter = nSpiltter; n:c)R8X]
q4)8]Y2
Y{]RhRR
} 'Wv=mBEfZ
") Xy%C`J
Xne{:!btw
public String getSSiteURL() k@qn'Zi
{ &r\pQ};
return sSiteURL; p#:.,;
} vas
s_} 1J,Y
]ee%=+'
public void setSSiteURL(String value) $xT'cl/IH
{ <&3qFK*9r
sSiteURL = value; ve.rpF\
} # [c`]v
FyuCYg \p
+(d\`{A
public String getSFilePath() HhfuHZ<
{ {9wBb`.n^
return sFilePath; y>zPsc,
} eJ0PSW/4l
bg$df 0
q7-Eu4w
public void setSFilePath(String value) ;Wjb}_V:_
{ a}l^+
sFilePath = value; so h3d
} E7E>w#T5
?`?"j<4e
"7_6iB&@<
public String getSFileName() AtNu:U$
{ )ymd#?wq
return sFileName; _iBNy
} !$ikH,Bh
BwO^F^Pr?k
<6k5nEh
public void setSFileName(String value) BR5r K
{ )cc:Z7p
sFileName = value; :4|W;Lkd!
} z38&7+
(7w`BR9B
fk%r?K6K
public int getNSplitter() ]Auk5M+
{ ;j]0GD,c$
return nSplitter; F$Q(2:w
} F)4Y;;#
&mj98
{<7!=@j
public void setNSplitter(int nCount) b!VaEK
{ 9j458Yd4*
nSplitter = nCount; tiJY$YqA
} Kx.I'_Qk
} =\Td~>
=s"_! 7
6Zwrk-,A
/* (Nd5VuI
**Utility.java dwOB)B@{H
*/ A=q)kcuy5
package NetFox; [@MV[$W5
yLFc?{~7
9(k5Irv"'h
public class Utility { ]8*#%^
XiE
d0YN:lJc
public Utility() ~0 <?^
{ _SM5x,Zd
6?nAO
&VtTUy}
} ML?%s`
cA_77#<8
//线程睡眠 3uO#/EbS
public static void sleep(int nSecond) dD@k{5
{ U%3d_"{;
try{ %(h-cuhq
Thread.sleep(nSecond); -miWXEe@l
} YnC7e2
catch(Exception e) Fl\X&6k
{ FHWzwi*u}
e.printStackTrace (); *x3";%o
} 4G;FpWQm
} "X~ayn'@w,
ZGrjb22M
//日志 y&T(^EA;
public static void log(String sMsg) a-\\A[E
{ K8CjZpzq
System.err.println(sMsg); 'vKB]/e;
} !<\"XxK+l
)%'Lm
ncS.~F
public static void log(int sMsg) ]nE_(*w
{ w5,p9f}.
System.err.println(sMsg); t]1j4S"pm
} MJ^NRT0?b
} yyZ}qnbx]
k{>rI2;
V*P3C5l
/* (3YqM7cqt
**TestMethod.java udxLHs
*/ W70J2
package NetFox; zh7#[#>t
@7xb/&N
r:.5O F}
public class TestMethod { c`~aiC`l
Qd"{2>
m[&]#K6
public TestMethod() [OJ@{{U%
{ ///xx/weblogic60b2_win.exe m)4s4P57y
try{ .m_yx{FZ=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;}),6R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l/[0N@r~
SiteFileFetch fileFetch = new SiteFileFetch(bean); %jEdgD%xV
fileFetch.start(); %m[ :},
} J0xOB;rd
catch(Exception e){e.printStackTrace ();} _urv We
}Y\Ayl
Hb5^+.xur
} 9u<4Q_I`
Ys,}L.
hPtSY'_@_
public static void main(String[] args) w :2@@)pr
{ i-!Z/,oL
new TestMethod(); =1g
} P6w!r>?6N
} ]0P-?O:
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