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)); wZrdr4j
} %t+V8A
for(int i=0;i<nEndPos.length-1;i++) ,PN>,hFL
{ UQW;!8J#R(
nEndPos = nStartPos[i+1]; 5-u=ZB%p
} I8^z\ef&
nEndPos[nEndPos.length-1] = nFileLength; sMO3eNLn
} ]s,T` (&
} -QS_bQG%
)sNtwSl^
miN(a; Q2P
//启动子线程 )_bXKYUX*0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; iQa Q"s
for(int i=0;i<nStartPos.length;i++) X#eVw|
{ \D}/tz5~B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @~gz-l^$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wRie{Vk
nStartPos,nEndPos,i); ;#xhlR* ~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9@vY(k k
fileSplitterFetch.start(); VCc4nn#
} dd4yS}yBlR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,hOJe=u46
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D]oS R7h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @&M$`b ^
nEndPos = " + nFileLength); ;UPw;'
// fileSplitterFetch[nPos.length-1].start(); >J8?n,*
_r,# l5~U
i!,>3
//等待子线程结束 m&ZdtB|
//int count = 0; n!tCz<v
//是否结束while循环 $\P!P.
boolean breakWhile = false; ,:z@Ji
uNx3us-
TS1k'<c?
while(!bStop) Jn:GqO
{ 'x6Mqv1W
write_nPos(); E|^a7-}|
Utility.sleep(500); !Sw7!h.ut
breakWhile = true; ;2X1qw>
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}D|"$*
for(int i=0;i<nStartPos.length;i++) TAGqRYgi
{ myJsRb5
if(!fileSplitterFetch.bDownOver) ="I]D I
{ 8\ :T*u3
breakWhile = false; !J6k\$r
break; K):)bL(B
} N:&Gv'`
} ]AfeaU'>
if(breakWhile) 12rr:(#%s
break; nq$^}L3&~
-EL"Sv?
f:BW{Cij;y
//count++; $T*kpUXH}
//if(count>4) 2 K` hH
// siteStop(); Li7/pUq>}!
} @h$7C<
>+G=|2
O"{NHNG\oT
System.err.println("文件下载结束！"); 7W 4[1
} Wk$%0xZ7
catch(Exception e){e.printStackTrace ();} Z4rK$B
} #&$4tTl
3 i>uKU1
ThFI=K
//获得文件长度 :@n e29,}
public long getFileSize() t/nu/yz5E
{ JZai{0se
int nFileLength = -1; %40|7O
try{ |*8 J.H*r
URL url = new URL(siteInfoBean.getSSiteURL()); '{C=vW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r_Xk:
httpConnection.setRequestProperty("User-Agent","NetFox"); 5 kQC
QhN5t/Hr
;[%AeN5W
int responseCode=httpConnection.getResponseCode(); [x9eamJ,H
if(responseCode>=400) XFH7jHnL+U
{ ?L7z\b"_~
processErrorCode(responseCode); P PmE.%_
return -2; //-2 represent access is error tX6n~NJ$
} d+z8^$z"
QL
fF<~2MiKw
String sHeader; ~kF^0-JZY
i?||R|>;"'
dTS7l02
for(int i=1;;i++) td{$c6
{ W!htCwnkF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *<]ulR2
//Utility.log(in.readLine()); ,uK }$l
sHeader=httpConnection.getHeaderFieldKey(i); _@SC R%
if(sHeader!=null) Un@dWf6'
{ X`#vH8
if(sHeader.equals("Content-Length")) {0QNqjue
{ arET2(h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _KLKa/3
break; g \&Z_
} (jtrQob
} M;-PrJdyt
else xrf z-"n4
break; 4Zo.c* BZ
} <0T|RhbY
} 5$d>:" >
catch(IOException e){e.printStackTrace ();} }k~ih?E^s
catch(Exception e){e.printStackTrace ();} J<yt/V]
Jx!#y A;
ot($aY,t
Utility.log(nFileLength); Kejp7okb
#~BsI/m
f; w\k7 #
return nFileLength; kNR -eG
} @>cz$##`
u%!/-&?wF
k#liYw I
//保存下载信息（文件指针位置） T\?$7$/V
private void write_nPos() XXPn)kmWR
{ 9kHVWDf
try{ %<8`(Uu5
output = new DataOutputStream(new FileOutputStream(tmpFile)); HCfme<'
output.writeInt(nStartPos.length); xsu9DzPf&{
for(int i=0;i<nStartPos.length;i++) %;_94!(hC
{ GZH{"_$
// output.writeLong(nPos); KW-GVe%8f
output.writeLong(fileSplitterFetch.nStartPos); ,4:=n$e 0
output.writeLong(fileSplitterFetch.nEndPos); /s*.:cdH
} Kv0V`}<Yc
output.close(); 4Hy/K^Ci
} 6S`0<Z;;/
catch(IOException e){e.printStackTrace ();} ~(nc<M[
catch(Exception e){e.printStackTrace ();} P q0%oz
} vMd3#@
UodBK7y
V6Mt;e)C
//读取保存的下载信息（文件指针位置） &hEn3u
private void read_nPos() *4/FN TC
{ HS[($
try{ :of(wZa3Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?4A/?Z]ub
int nCount = input.readInt(); o?Aj6fNY?
nStartPos = new long[nCount]; m _cRK}>
nEndPos = new long[nCount]; _Jy7` 4B.
for(int i=0;i<nStartPos.length;i++) 2n)?)w]!M
{ 85YUqVi9
nStartPos = input.readLong(); z',Fa4@z
nEndPos = input.readLong(); ],_+J*
} )adV`V%=>
input.close(); N_IKH)
} s$).Z(6
catch(IOException e){e.printStackTrace ();} ,DZvBS
catch(Exception e){e.printStackTrace ();} ]}dQ~lOE
} m8ts!6C
3/>7b(
Q_U.J0
private void processErrorCode(int nErrorCode) CHsg2S
{ jMgXIK\
System.err.println("Error Code : " + nErrorCode); RN[I%^$"
} 12a`,~
L8 L1_
/M_$4O;*@
//停止文件下载 @^xtxtjzux
public void siteStop() &W,jR|B
{ z@yTkH_
bStop = true; )V\@N*L`ik
for(int i=0;i<nStartPos.length;i++) 6Q^~O*cw
fileSplitterFetch.splitterStop(); ikW[lefTq
_p^"l2%D/
Zge(UhZ
} <.Ws; HN}
} Iko]c_W0
//负责部分文件的抓取 O2?C *
**FileSplitterFetch.java 'v"=
*/ Nob(D'vSr
package NetFox; } o%^ Mu B
j{@6y
^U}k
import java.io.*; c2y,zq|H
import java.net.*; mHxR4%i5
}d<R 5
U[@y8yN6M
public class FileSplitterFetch extends Thread { qhEv6Yxfw6
w G%W{T$
p49]{2GXb
String sURL; //File URL T3X'73M
long nStartPos; //File Snippet Start Position FEaT}/h;
long nEndPos; //File Snippet End Position 5~L]zE
int nThreadID; //Thread's ID mQj=-\p
boolean bDownOver = false; //Downing is over Ao\xse{E
boolean bStop = false; //Stop identical uM-,}7f7
FileAccessI fileAccessI = null; //File Access interface .T| }rB<c
n0xGIq
*MP.YI:h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S#7YJ7 K"N
{ LQ jbEYp
this.sURL = sURL; |A8@r&
this.nStartPos = nStart; +0'F@l
this.nEndPos = nEnd; o~Se[p
nThreadID = id; 8xAV[i
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K^Awf6%
} !@xO]Jwv
l~c[}wv
NRi5 Vp2=
public void run() &*C5Nnlv
{ kZ40a\9 Ye
while(nStartPos < nEndPos && !bStop) /jY u-H+C
{ WYP;s7_
#b/qR^2qW
0MG>77
try{ UUah5$Iy
URL url = new URL(sURL); d1b]+AG4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D|]BFu)F
httpConnection.setRequestProperty("User-Agent","NetFox"); _BczR:D*
String sProperty = "bytes="+nStartPos+"-"; [q<'ty
httpConnection.setRequestProperty("RANGE",sProperty); KZm&sk=QM-
Utility.log(sProperty); vgz`+Zj*S
3H,E8>Vd
,,H"?VO
InputStream input = httpConnection.getInputStream(); OQVrg2A%(
//logResponseHead(httpConnection); hAGHb+:
(]|h6aI'}
g@.$P>Bh
byte[] b = new byte[1024]; h9vcN#22D
int nRead; )!T~l(g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) | f#wbw
{ zM'eqo>!c>
nStartPos += fileAccessI.write(b,0,nRead); ]%Q!%uTh
//if(nThreadID == 1) LP<A q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q;h.}N8W
} D /eH~
Shn,JmR
|VfEp
Utility.log("Thread " + nThreadID + " is over!"); %y1!'R:ZW
bDownOver = true; gP^2GnjHL8
//nPos = fileAccessI.write (b,0,nRead); 0-. d{P
} @u~S!(7.Wi
catch(Exception e){e.printStackTrace ();} -YRIe<}E -
} Z;BS@e
} Gp"GTPT{
bJ^JK
zWsr|= [
//打印回应的头信息 h$cm:uks
public void logResponseHead(HttpURLConnection con) 5&]5*;BvJ
{ @"@a70WHk
for(int i=1;;i++) 96=<phcwN[
{ ]hl*6
String header=con.getHeaderFieldKey(i); Y.:R-|W
if(header!=null) iD^,O)b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); SI(f&T(
Utility.log(header+" : "+con.getHeaderField(header)); Fr%#
else O-iE0t
break; <p@Cx
} .RD<]BxJ
} NOb`)qb
f/Gx}x=
v.0qE}' |
public void splitterStop() "c^!LV
{ '&>"`q
bStop = true; 8K%N7RL|
} GP:<h@:798
k.J%rRneN
XLh)$rZ
} Q>niJ'7WF
(?FH`<
$vn6%M[
/* Psb !Z(
**FileAccess.java I-#H+\S
*//文件访问(定位，写) {X{R]
package NetFox; WQ|:TLQ
import java.io.*; r )|3MUj
dFg>uo
`Rq=:6U;3
public class FileAccessI implements Serializable{ -4Qub{Uym
bM W|:rn
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ee>VA_ss
RandomAccessFile oSavedFile; XF`2*:7
long nPos; b?wrOS
h>Kx
]m1fo'
public FileAccessI() throws IOException 5Cf!NNV
{ unDW2#GX
this("",0); X9>fE{)!
} @N'n>8Wn
Bfb~<rs[
2=cx`"a$
public FileAccessI(String sName,long nPos) throws IOException y<`5
{ <,vIN,Kl8/
oSavedFile = new RandomAccessFile(sName,"rw"); 5(;Y&?k
this.nPos = nPos; t~2oEwTm
oSavedFile.seek(nPos); >a3m!`lq
} ~E}kwF
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Y;w|Fvjj+
public synchronized int write(byte[] b,int nStart,int nLen) Omd;
{ =4TQ*;V:
int n = -1; 5SFr E`
try{ Y1r$;;sH
oSavedFile.write(b,nStart,nLen); :>-zT[Lcn
n = nLen; w4 yrAj 2
} #.8v[TkKq
catch(IOException e) !Uiq3s`1T
{ p.:651b
e.printStackTrace (); ^^q&VL
} M+"6VtZH
b'4a;k!rS
?mMM{{%(.
return n; nDi^s{
} '}agi.z
]*dYX=6
z+Xr2B
} /gAT@Vx
:'h$]p%
}$oS/bo
/* t 7Y*/v&P(
**SiteInfoBean.java m.++nF
*/ tSy 9v
package NetFox; |s3;`Nxu7
qV=:2m10x
0 u*a=f=
public class SiteInfoBean { 8T+9 fh]I
9]Jv >_W*
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private String sSiteURL; //Site's URL l]G iz&
private String sFilePath; //Saved File's Path H*]Vs=1
private String sFileName; //Saved File's Name A%#M#hD/
private int nSplitter; //Count of Splited Downloading File #91^1jyMf
P!-RZEt$
DE.].FD'
public SiteInfoBean() RKLE@h7[?
{//nSplitter的缺省值为5 )\yK61aX
//default value of nSplitter is 5 =!-}q
this("","","",5); )4rt-_t<
} =`x }9|[
Cl'$*h
{ <Gyjq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "U^m~N9k{
{ @QTw9,pS
sSiteURL= sURL; lEl.'X$
sFilePath = sPath; HGAi2+&
sFileName = sName; YM`T"`f
this.nSplitter = nSpiltter; N]FRL\K
wa<k%_# M
% PzkVs
} A+^okT37r
\k5"&]I3
/"J 6``MV
public String getSSiteURL() a/uo)']B
{ xc*a(v0
return sSiteURL; e1g3a1tnWl
} frUs'j/bZ
x^@oY5}cr
n UmyPQ~
public void setSSiteURL(String value) S'5)K
{ nrY)i_\
sSiteURL = value; "dP-e
} hZfj$|<
G@/iK/>5|`
^R:&c;&,
public String getSFilePath() 9287&+,0r
{ pl%!AY'oE>
return sFilePath; |kK5:\H
} I#xdksY
N ;=zo-8
%SB4_ r*<
public void setSFilePath(String value) :+6W%B
{ FkrXM!mJ
sFilePath = value; ~-Kx^3(#
} el`?:dY H
Xr=BxBttp
^+Nd\tp
public String getSFileName() YIwa =^
{ b9rQQS
return sFileName; C*ep8{B
} i=\)[;U
MJch Z
?:3hp2k<
public void setSFileName(String value) 27N;>
{ HSysME1X:/
sFileName = value; .Pj<Pe
} R/x3+_.f
[L2+k? *
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public int getNSplitter() o3hgkoF
{ ;>mM9^Jaf
return nSplitter; ;Tnid7:S
} (9RfsV4^
C0[U}Y/r2
"x9yb0
public void setNSplitter(int nCount) jbipNgxkr
{ B?i#m^S
nSplitter = nCount; 0&sa#g2
} +ZNOvcsV
} T+nID@"36
FA*$ dwp
JrOxnxd^
/* LH2B*8=^2
**Utility.java %4m Nk}tyH
*/ dvjj"F'Bf
package NetFox; Ht;Rz*}
uQ-GJI^t
uX1;
public class Utility { fYjmG[4
IWu=z!mO
A]!0Z:{h%
public Utility() zEFS\nP}E
{ E#+2)Q
j7Fb4;o{
0YFXF
} eZOR{|z
.4\I?
//线程睡眠 f;^ +q-Q
public static void sleep(int nSecond) : B&~q$
{ syBpF:`-W
try{ < 8' b
Thread.sleep(nSecond); _jG|kjFTc
} Zq85q
catch(Exception e) Oq~{HJ{
{ y!gPBkG&3n
e.printStackTrace (); L@GICW~
} tV(iC~/
} B1_9l3RM
Gt#r$.]W?o
//日志 +8zACs{p
public static void log(String sMsg) VQpt1cK*
{ 1ARtFR2C{b
System.err.println(sMsg); HSNj
} [T r7SU#x
uSR%6=$
"qq$i35x
public static void log(int sMsg) }&=l)\e
{ E~}H,*)
System.err.println(sMsg); :G 5p`;hGo
} u!D?^:u=)
} W,[ RB
M _< |n
9ia&/BT7"z
/* (E0WZ$f}
**TestMethod.java !QwB8yK@
*/ y`zdI_!7
package NetFox; WDghlC6g!l
5/P. 4<c7
Vwp>:'Pu
public class TestMethod { LAc60^t1
;U4O`pZ
RjVUm+<
public TestMethod() gH(#<f@ZI
{ ///xx/weblogic60b2_win.exe uB"B{:Kz
try{ IrYj#,xJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X$;x2mz nM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9`92 >
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z#u{th
fileFetch.start(); w%`S>+kX&
} O8#]7\)
catch(Exception e){e.printStackTrace ();} r jn:E
>uZc#Zt
8OOAPp$%|
} W>!:K^8]
p,z>:3M
C"n!mr{srt
public static void main(String[] args) mQVlE__ub
{ '['%b
new TestMethod(); wclj9&k
} |(tl a_LE
} >.UEs8QV
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