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)); <xeo9'k6&
} 3xnu SOdh
for(int i=0;i<nEndPos.length-1;i++) |k^ *
{ "|l-NUe
nEndPos = nStartPos[i+1]; \aG:l.IM0
} 4l*4wx""v
nEndPos[nEndPos.length-1] = nFileLength; W8 m*co
} L'Fy\K\
} A_WtmG_9
*FT )`
bqDHLoB\1
//启动子线程 "m:4e`_dz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o-jF?9m
for(int i=0;i<nStartPos.length;i++) tgbr/eCoU
{ ]h$,=Qf hD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ' Z}/3 dp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Dj9).lgc
nStartPos,nEndPos,i); Zu/}TS9bi
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8?rRLM4
fileSplitterFetch.start(); $lMEZt8A
} r%/*,lLO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H]7;OM/g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3yfq*\_uXw
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )} H46
nEndPos = " + nFileLength); yS[Z%]bvU
// fileSplitterFetch[nPos.length-1].start(); 2nRL;[L*.
E5<}7Pt
VfiMR%i}
//等待子线程结束 IJAWG
//int count = 0; e/;chMCq
//是否结束while循环 2$O@T]
boolean breakWhile = false; ?][2J
93npzpge
?>W4*8(
while(!bStop) 0#rv.rJ{
{ !be6}
write_nPos(); -B-nTS`
Utility.sleep(500); cR1dGNcp/@
breakWhile = true; 2I#4jy/g
f:h.O# d>
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for(int i=0;i<nStartPos.length;i++) 9s-op:5
{ w8Mi:;6
if(!fileSplitterFetch.bDownOver) mb\}F9
{ zW_V)UNe
breakWhile = false; Sh=Px9'i
break; x^|J-
} YEWHr>&Z
} w-%H\+J
if(breakWhile) lr[a~ca\
break; w$cic
xPY/J#X$
0omg%1vt<A
//count++; E Cx_ [|3{
//if(count>4) <ealt
// siteStop(); F-)lRGw
} <}3c%Q1
L$GhM!c
yVyh'd:Ik
System.err.println("文件下载结束！"); M[ (mH(j
} ,HEx9*E/s
catch(Exception e){e.printStackTrace ();} e4V4%Qw
} AT:T%a:G?
d))(hk:
$Wy7z^t
//获得文件长度 an 3"y6.8
public long getFileSize() NW`.RGLI<
{ xP.B,1\X
int nFileLength = -1; ,x?H]a)
try{ bc"E=z
URL url = new URL(siteInfoBean.getSSiteURL()); }TZ5/zn.Dw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B8^tIq
httpConnection.setRequestProperty("User-Agent","NetFox"); 3:i4DBp,i
UlHRA[SCv
R<gC,eV<=
int responseCode=httpConnection.getResponseCode(); 0}YR=
if(responseCode>=400) Rla4XN=mf
{ ~EIY(^|py
processErrorCode(responseCode); v2dCkn /
return -2; //-2 represent access is error ?gb"S,
} _=1SR\
hv'~S
z^Nnt
String sHeader; b'^OW
${#5$U+kI
I72UkmK`
for(int i=1;;i++) }ZEh^zdz8
{ zi23k=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N7%+n*Z
//Utility.log(in.readLine()); 5r<%xanXW/
sHeader=httpConnection.getHeaderFieldKey(i); "-y\F}TE
if(sHeader!=null) Q/6T?{\U7
{ dhN[\Z%
if(sHeader.equals("Content-Length")) Ru Q\H0pr
{ p;:tzH\l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <0T4MR7
break; (}fbs/8\p
} aC>r5b#:
} TRrO-
else .9Bimhc6K
break; e0HG"z4
} PKR0y%Ar
} "_ b Sy
catch(IOException e){e.printStackTrace ();} PNXZ3:W
catch(Exception e){e.printStackTrace ();} J.:"yK""
.Lo$uKsW$l
/d5_-AB(v
Utility.log(nFileLength); a\\B88iRRZ
4@|K^nT`
h)q:nlKUW
return nFileLength; PG9won5_
} $Trkow%F]
=1lKcA[z
J={$q1@lq
//保存下载信息（文件指针位置） -9/YS
private void write_nPos() 9U6y<X
{ 6rL'hB!!]*
try{ j4le../N
output = new DataOutputStream(new FileOutputStream(tmpFile)); GEwgwenv
output.writeInt(nStartPos.length); TH/!z,(>
for(int i=0;i<nStartPos.length;i++) &-+qB >SK>
{ 4hztYOhJ{
// output.writeLong(nPos); epm t
output.writeLong(fileSplitterFetch.nStartPos); R! ?8F4G
output.writeLong(fileSplitterFetch.nEndPos); +&tY&dQQB
} *9%<}z
output.close(); f3U#|(%(*
} A\ze3fmV
catch(IOException e){e.printStackTrace ();} BD,JBu]
catch(Exception e){e.printStackTrace ();} UuAn`oYhV
} mwCNfwb:
-B$oq8)n*
{$>*~.Wu
//读取保存的下载信息（文件指针位置） OekcU%C
private void read_nPos() -:m;ePK
{ 4QK([q
try{ whoz^n3NE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F&;g< SD
int nCount = input.readInt(); dW<.
nStartPos = new long[nCount]; pq*b"Jku1
nEndPos = new long[nCount]; fu9y3`
for(int i=0;i<nStartPos.length;i++) BgD;"GD*W
{ h|dVVCsN
nStartPos = input.readLong(); Mq42^m:qe
nEndPos = input.readLong(); d6<,R;)
} u.0Z)j}N
input.close(); nTY`1w.;
} @.T'
catch(IOException e){e.printStackTrace ();} |A7Yv
catch(Exception e){e.printStackTrace ();} :D-d`OyjG>
} Ka2U@fK"
`?rPs8+R
@fT*fv
private void processErrorCode(int nErrorCode) p{!aRB%
{ Vlce^\s;
System.err.println("Error Code : " + nErrorCode); -hL8z$}
} 5|xFY/%
{LJwW*?
9+9}^B5@A
//停止文件下载 29u"\f a
public void siteStop() $WnK
{ #@Zz Bf
bStop = true; ag14omM-
for(int i=0;i<nStartPos.length;i++) G?e,Q$
fileSplitterFetch.splitterStop(); v@`#!iu
6,uW{l8L
LcE!e%3
} }@4m@_gR?
} B c*Rn3i@
//负责部分文件的抓取 j)C%zzBu(
**FileSplitterFetch.java XV)ej>A-V
*/ t3 *2Z u
package NetFox; Hy|$7]1
%S$`cp
X~5TA)h;~
import java.io.*; iYHD:cg)~
import java.net.*; =bZ>>-<
k x6%5%
R7e`Wn
public class FileSplitterFetch extends Thread { l:8gCi
]XJpy-U
jr*A1y*
String sURL; //File URL g$?B!!qT
long nStartPos; //File Snippet Start Position o9#
long nEndPos; //File Snippet End Position ~!,'z
int nThreadID; //Thread's ID <'-}6f3
boolean bDownOver = false; //Downing is over G#)>D$Ck#
boolean bStop = false; //Stop identical 4Me*QYD
FileAccessI fileAccessI = null; //File Access interface 5IBe;o
E0>4Q\n{
@;fdf3ian
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException TWEmW&Q
{ 5ts8o&|
this.sURL = sURL; XkCbdb
this.nStartPos = nStart; d'kQE_y2.
this.nEndPos = nEnd; tu6c!o,@
nThreadID = id; z++*,2F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^g~Asz5]
} C:_!zY'z
%xyt4}-)m
K4N~ApLB+
public void run() 45edyQ
{ |`U^+Nf
while(nStartPos < nEndPos && !bStop) !?Z}b.%W
{ ,78QLh9:
my[)/'
niFX8%<hP
try{ I^[R]Js
URL url = new URL(sURL); /o.wCy,J<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2 Nr j@q
httpConnection.setRequestProperty("User-Agent","NetFox"); Z%N{Y x(
String sProperty = "bytes="+nStartPos+"-"; G!8O*4+A
httpConnection.setRequestProperty("RANGE",sProperty); pYI`5B4
Utility.log(sProperty); MH?|>6
PD$ay^Y
:'f#0ox
InputStream input = httpConnection.getInputStream(); aa.EtKl
//logResponseHead(httpConnection); S$%T0~PR~
hp%|n:.G
4M6o+WV
byte[] b = new byte[1024]; =KmjCz:
int nRead; XtNe) Ry
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bb$1RLyRL
{ oS/<)>\Gv
nStartPos += fileAccessI.write(b,0,nRead); VZ}^1e
//if(nThreadID == 1) ul?'kuYk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8QE0J$d5
} l-XiQ#-{
{uL<$;#i
:7e2O!zH_
Utility.log("Thread " + nThreadID + " is over!"); ya5;C"
bDownOver = true; pTST\0?
//nPos = fileAccessI.write (b,0,nRead); Um4 }`
} tUGnD<P
catch(Exception e){e.printStackTrace ();} s59v* /
} *["9;_KD
} YnNB#x8|
UVUbxFq:
!Jh-v
//打印回应的头信息 G>M# BuU
public void logResponseHead(HttpURLConnection con) f:B+R
{ .*r?zDV
for(int i=1;;i++) `*&*jdq&i
{ PnFU{N
String header=con.getHeaderFieldKey(i); xA`Q4"[I
if(header!=null) S?D|"#-,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pez[qs
Utility.log(header+" : "+con.getHeaderField(header)); 6U @3 xU`
else %?<C ?.
break; kmi[u8iXD_
} (VO) Q
} w_ kHy_)
IwZn%>1N
e/6WhFN#
public void splitterStop() n (C*LK
{ GLcf'$l
bStop = true; d?oupW}uu
} 1C{n!l
y/$WjFj3"
!qV{OXdrB
} " nq4!
m[LIM}Gu
!<h*\%;
/* *%:p01&+
**FileAccess.java ZC_b`q<
*//文件访问(定位，写) c;xL.
package NetFox; d}EGI
import java.io.*; 2Y(Phw2%
~x)Awdlu
K,&)\r kzD
public class FileAccessI implements Serializable{ N0O8to}V
$LRvPan`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -w1U/o.
RandomAccessFile oSavedFile; _UT>,c;h
long nPos; Dq)V] Zx
@g }r*U?
*Y?rls`
public FileAccessI() throws IOException <T)9mJYr
{ I+kGEHO}
this("",0); V()s!w
} L~"~C(g
'\(Us^Ug
MBIt)d@Ix
public FileAccessI(String sName,long nPos) throws IOException N|O/3:P<,U
{ N$aLCX
oSavedFile = new RandomAccessFile(sName,"rw"); T6=c9f?7
this.nPos = nPos; f>s3Q\+
oSavedFile.seek(nPos); LcoJltY{5
} Om0Z\GP=
@.yp IE\
[c+[t3dz
public synchronized int write(byte[] b,int nStart,int nLen) "9!ln
{ WogJ~N,d53
int n = -1; VE+Q Y9(
try{ :XxsDD
oSavedFile.write(b,nStart,nLen); BKPXXR
n = nLen; b/:9^&z
} ?[hIv6c
catch(IOException e) +;c)GNQ)6:
{ a}|B[b
e.printStackTrace (); R+Dx#Wn I
} dGt;t5AnV
f>k]{W Y
8)s}>:}
return n; Rb Jl;
} oS 7q#`
0j %s H
dZFf/BXU
} qZ'&zB)
c~3OK_k
V2Q2(yvdJ
/* sWX iY
**SiteInfoBean.java OCnQSkj
*/ a x4V(
package NetFox; \L>3E#R-Q
RZ#b)l
5<wIJ5t
public class SiteInfoBean { sMlY!3{Ix
NYA,
~2@+#1[g8z
private String sSiteURL; //Site's URL LX[<Wh_X(
private String sFilePath; //Saved File's Path @;_xFL;{g
private String sFileName; //Saved File's Name .K]n<+zW
private int nSplitter; //Count of Splited Downloading File "_WOtJr
=+%QfuK
S@*lI2
public SiteInfoBean() :V*c9,>ZO
{//nSplitter的缺省值为5 wa-#C,R\_#
//default value of nSplitter is 5 "#\\p~D/<
this("","","",5); :*u .=^
} 9gVu:o1/
v^1_'PAXu
k%YvJXL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L'B= =#
{ `qnSq(tNq
sSiteURL= sURL; Clr~:2g\
sFilePath = sPath; ?9'Ukw` g
sFileName = sName; =&jLwy
this.nSplitter = nSpiltter; =Y Je\745
h}r.(MVt
U2m86@E
} LfOXgn\
[vh&o-6
{Z%4Pg
public String getSSiteURL() }iZO0C
{ 2L Kpwz?
return sSiteURL; <Dojl #
} 5V5Nx(31i
.`*h2
Mhp6,JL
public void setSSiteURL(String value) 3]"RaI4Q0
{ V<:scLm#OF
sSiteURL = value; wXI6KN-
} '0|0rwx
"I+71Ce
u}Kc>/AF
public String getSFilePath() S bI7<_
{ E>>@X^ =
return sFilePath; LgFF+z
} qM%l
$fZVh%
w6FtDl$
public void setSFilePath(String value) P(AcDG6K
{ |rW,:&;
sFilePath = value; n1n->l*HGP
} s\&qvL1D
}\Kki
ukNB#2"
public String getSFileName() .rpKSf.
{ is`O,Met
return sFileName; :+Ti^FF`w
} r0jhIE#
rUgTJx&ds
T7+_/ Qh
public void setSFileName(String value) t$+[(}@+
{ K6 D3
sFileName = value; 86+nFk
} bz$)@gLc
N;N,5rxV
4FLL*LCNX
public int getNSplitter() (NB\wJg $
{ G_OLUuK?C
return nSplitter; mtfEK3?2*
} NABVU0}
^q{=mf`
KlOL5"3
public void setNSplitter(int nCount) V% -wZL/
{ =VXxQ\{
nSplitter = nCount; QxUsdF?p
} SA3!a.*c
} W<']Q_su
6IRzm6d
leY fF
/* ";vP77|m7R
**Utility.java )S~ySiJ<U
*/ oW7\T!f
package NetFox; &4]~s:F
lJ y\Ky(*
A\xvzs.d
public class Utility { M{)7C,'
AE?G+:B
2$S^3$k'
public Utility() bSbUf%LKt
{ 7l+>WB_]
@xu/&pbI
Cx,)$!1
} 22`N(_
@-d0~.S
//线程睡眠 ~:PuKx
public static void sleep(int nSecond) A08b=S
{ iRwlK5(&
try{ vBRW5@
Thread.sleep(nSecond); >n!,KUu]
} 7"|j.Yq$H{
catch(Exception e) !`UHr]HJ
{ uW@o,S0:
e.printStackTrace (); 6<%W8m\
} e 9p+
} t93iU?Z
wfE%` 1
//日志 ;8VvpO^G/
public static void log(String sMsg) PR{y84$
{ 3jaY\(`%h
System.err.println(sMsg); WZ#|?pJ
} jjbw+
d|~A>YZ
k~P{Rm;F
public static void log(int sMsg) OI0tgkG
{ W5#5RK"uX
System.err.println(sMsg); ga#Yd}G^~3
} O7KR~d
} gp?|UMA9.
JE[+
1Vden.H*CI
/* *CnrzrKtQ
**TestMethod.java ohy?l
*/ Wd0$t
package NetFox; #!h +K"wX
Y64B"J=P9
x?|C-v
public class TestMethod { c[a1 Md&
*,Mg
Xy;!Q`h(
public TestMethod() Z T5p
{ ///xx/weblogic60b2_win.exe 6Eu&%`
try{ G0u3*.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Gkfc@[Z V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .W9/*cZV0
SiteFileFetch fileFetch = new SiteFileFetch(bean); cdH Ug#
fileFetch.start(); ~w>Z !RuhT
} Ob|[/NN
catch(Exception e){e.printStackTrace ();} l:Y$A$W]>
[;]@PKW?w
JN{xh0*
} _tGR:E
%5zztReI
9gz"r
public static void main(String[] args) aD5G0d?u
{ VB?mr13}G
new TestMethod(); +]!`>
} o`@B*, @
} JW5SBt>
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