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)); Qy"%%keV'T
} jJw
for(int i=0;i<nEndPos.length-1;i++) :-#7j} R&
{ T59FRX
nEndPos = nStartPos[i+1]; "=n%L +6%
} nTc#I~\
nEndPos[nEndPos.length-1] = nFileLength; BKO^ux%
} cWyf04-?
} \BH?GMoP
Xp|4WM
QnOs8%HS-
//启动子线程 Y'jgp Vt
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9mp`LT
for(int i=0;i<nStartPos.length;i++) E.;Hm;
{ n:B){'S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A W6B[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y`8U0TE3R
nStartPos,nEndPos,i); V~#5^PF{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I$S*elveG
fileSplitterFetch.start(); Du +_dr^4
} "=+i~N#Sc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WF*j^ %5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?$ov9U_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Dq%}({+
nEndPos = " + nFileLength); )7!,_r
// fileSplitterFetch[nPos.length-1].start(); %QrOEs
^!C
_.R]K$U
//等待子线程结束 M:(.aEe
//int count = 0; Nt_sV7zzb
//是否结束while循环 c$)>$&([
boolean breakWhile = false; !( +M
?7TmAll<.s
cAGM|%
while(!bStop) }f_@@#KB?
{ RhmkpboucC
write_nPos(); J @~g>
Utility.sleep(500); o3\^9-jmp
breakWhile = true; uPbdzUk$
wSCI?
3N!v"2!#
for(int i=0;i<nStartPos.length;i++) \!jz1`]&{
{ =jh^mD&'
if(!fileSplitterFetch.bDownOver) Mv/ SU">F
{ nh0gT>a>@
breakWhile = false; <+r~?X_
break; p5OoDo
} `Ix`/k}
} !5h-$;
if(breakWhile) 'AWWdz
break; zt9A-% \R
9=6BQ`u
Nxl#]
//count++; :-U&_%#w
//if(count>4) =bP<cC=3b
// siteStop(); Y@q9
} oiR9NB&<
Z_dL@\#|
THX% z `
System.err.println("文件下载结束！"); vol (%wB
} },}g](!m
catch(Exception e){e.printStackTrace ();} ]8OmYU%6V
} h+!R)q8M
etX(~"gG_
\p}GW
//获得文件长度 hP{+`\&<f
public long getFileSize() k,'MmAz
{ 0~_I9|FN
int nFileLength = -1; k:iy()n[
try{ XYD-5pG
URL url = new URL(siteInfoBean.getSSiteURL()); J#j3?qrxu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <Piq?&VX[
httpConnection.setRequestProperty("User-Agent","NetFox"); ZybfqBTD&c
Wl=yxJu_(
TG8U=9qt
int responseCode=httpConnection.getResponseCode(); of7p~{3H
if(responseCode>=400) 6&6dd_K(
{ ? p[Rv
processErrorCode(responseCode); S76MY&Vx23
return -2; //-2 represent access is error LkK&<z
} Wi5Dl=
Isvb;VT9L
N}[!QE
String sHeader; T*Ge67
ToKG;Ff4b
w'_|X&@H
for(int i=1;;i++) =d<~:!)
{ m+7%]$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !B#lZjW#
//Utility.log(in.readLine()); !2&)6SL/
sHeader=httpConnection.getHeaderFieldKey(i); Khv}q.)F
if(sHeader!=null) {*g{9`
{ F4"bMN
if(sHeader.equals("Content-Length")) P_mP ^L
{ `-cw[@uD
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `'P&={p8
break; (nBh6u*
} -$#2?/uqC
} 4bdCbI
else J(~1mIJjC
break; i4WHjeo\
} O[L#|_BnEO
} HE_UHv
catch(IOException e){e.printStackTrace ();} (E,[Ad,$
catch(Exception e){e.printStackTrace ();} Unq~lt%2
}M"])B I
'qde#[VB
Utility.log(nFileLength); VM&Ref4
s S3RK
W?!rqo2SP
return nFileLength; Hi$N"16A5z
} LH @B\ mS
9M1DE
~Al3Dv9x
//保存下载信息（文件指针位置） .q:6F*,1M
private void write_nPos() ZdY$NpR,
{ Q3$DX,8?
try{ Hd7Vp:KM
output = new DataOutputStream(new FileOutputStream(tmpFile)); v$JW7CKA
output.writeInt(nStartPos.length); v+trHdSBYE
for(int i=0;i<nStartPos.length;i++) cUd>ahv
{ 8'qlg|{!~
// output.writeLong(nPos); j"pyK@v2B
output.writeLong(fileSplitterFetch.nStartPos); (Uu5$q(
output.writeLong(fileSplitterFetch.nEndPos); .V}bfd[k$
} ieWXr4@:
output.close(); XhWo~zh"
} =oiz@Q@H
catch(IOException e){e.printStackTrace ();} y0?HZ Xq
catch(Exception e){e.printStackTrace ();} qe e_wx
} cH:&S=>h
iPG:w+G
YSfJUB!I
//读取保存的下载信息（文件指针位置） o@[o6.B<
private void read_nPos() #4"eQ*.*"
{ r4X\/
try{ 5.oY$tb(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :J x%K
int nCount = input.readInt(); & @_PY
nStartPos = new long[nCount]; Ku uiU= (L
nEndPos = new long[nCount]; |yp^T
for(int i=0;i<nStartPos.length;i++) )Spa F)N8
{ (]&B'1b
nStartPos = input.readLong(); "cjD-42
nEndPos = input.readLong(); Zy?!;`c*{
} GNB'.tJ:0Y
input.close(); :9x]5;ma
} i-p,x0th
catch(IOException e){e.printStackTrace ();} f w)tWJVD
catch(Exception e){e.printStackTrace ();} p0l.f`B
} VQ2'a/s
M$>Nd6,@N
aZa1eE
private void processErrorCode(int nErrorCode) $nIE;idk
{ )"{}L.gC6
System.err.println("Error Code : " + nErrorCode); }vgM$o
} +;pw^QB
pzQc UG
nox-)e
//停止文件下载 saQo]6#
public void siteStop() iyUnxqP
{ ,+C?UW
bStop = true; (G$Q\>
for(int i=0;i<nStartPos.length;i++) =,qY\@fq
fileSplitterFetch.splitterStop(); eOXu^M>:F
:=!6w
b KDD29
} 9PG{>W$M
} gVJh@]8)
//负责部分文件的抓取 "WXUz
**FileSplitterFetch.java -?{g{6
*/ qx*b\6Rt
package NetFox; [0kZyjCq@
8ql<7RTM!
4OO^%`=)M'
import java.io.*; {9j0k`A
import java.net.*; P%vouC0W
ZnRj}y
@7Ln1v
public class FileSplitterFetch extends Thread { >Lo'H}[pF
.A6pPRy e
9asA-'fZ
String sURL; //File URL H0t#J
long nStartPos; //File Snippet Start Position -=UvOzw
long nEndPos; //File Snippet End Position K9VP@[zbJ
int nThreadID; //Thread's ID Yb[)ETf^
boolean bDownOver = false; //Downing is over pa?AKj]
boolean bStop = false; //Stop identical rTJqw@]#WH
FileAccessI fileAccessI = null; //File Access interface H+gB|
Ro<5c_k
L>hLYIW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException };Df ><
{ 7`)RBhGB
this.sURL = sURL; 3|)cT1ej
this.nStartPos = nStart; \S?-[v*{
this.nEndPos = nEnd; 8 K)GH:a
nThreadID = id; ]+w 27!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jG}nOI
} f8f3[O!x
)7P>Hj
*g:Dg I 2
public void run() WHLTJ]OB
{ d#ab"&$bv
while(nStartPos < nEndPos && !bStop) )/OIzbA3#
{ [{&OcEf
*] >R
f/0k,~,*
try{ Z$('MQ|Ur
URL url = new URL(sURL); YbZ?["S&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3Y +;8ld
httpConnection.setRequestProperty("User-Agent","NetFox"); tF<&R&=
String sProperty = "bytes="+nStartPos+"-"; gdyWuOxa|
httpConnection.setRequestProperty("RANGE",sProperty); Zm6jF
Utility.log(sProperty); 'r-B%D=
W&I:z-VH
GGZ9DC\{
InputStream input = httpConnection.getInputStream(); auY?Cj'"fs
//logResponseHead(httpConnection); Klu0m~X@
I?\P^f
sdd%u~4,X
byte[] b = new byte[1024]; z`u$C+Ov
int nRead; h+YPyeAs
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !g|[A7<|
{ '*&V7:
nStartPos += fileAccessI.write(b,0,nRead); wLE|J9t%Ea
//if(nThreadID == 1) W>b\O">
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v=&xiwz}
} _KyhX|
Ar_Yl|a
p-!/p#
Utility.log("Thread " + nThreadID + " is over!"); )lUocm
bDownOver = true; @|OGxQoC
//nPos = fileAccessI.write (b,0,nRead); ! 8Ro5),
} cmd7-2
catch(Exception e){e.printStackTrace ();} "s`#`'
} *kj+6`:CPs
} N?A}WW#
K,P`V &m?
C&EA@U5X^
//打印回应的头信息 AnZy oa
public void logResponseHead(HttpURLConnection con) `J7@G]X;2
{ }<'ki ;
for(int i=1;;i++) tv]9n8v
{ =*6H!bzX
String header=con.getHeaderFieldKey(i); HuN_$aP
if(header!=null) 4>B=k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9c0
Utility.log(header+" : "+con.getHeaderField(header)); R-4#y%k<
else <p` F/p-
break; Dv^M/z2&[
} k@>(sXs
} lx~C{tl2
ys7Tq+
y^ st T^
public void splitterStop() XF@34b5(
{ DoICf1
bStop = true; [8acan+ 2l
} d5=&:cF
9El{>&Fs4
T=g2gmo9
} PbV1FB_
4O{,oN~7
F"23vG>3
/* N~?#Qh|ZnU
**FileAccess.java jPc,+?
*//文件访问(定位，写) Y|KT3
package NetFox; Cw5B p9
import java.io.*; nLrCy5R:
>Wd_?NaI
x4?g>v*J
public class FileAccessI implements Serializable{ PT4iy<
DTdqwe6pi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JM*!(\Y
RandomAccessFile oSavedFile; a`U/|[JM
long nPos; = ^%*:iT
h=kC3ot\
4`+R |"4
public FileAccessI() throws IOException dI%Nwl%
{ 6r h#ATep
this("",0); m1sV~"v;
} L/N%ft]!T
| `?J2WGe
@ykl:K%ke
public FileAccessI(String sName,long nPos) throws IOException Nr*o RYY
{ ?ihRt+eR~
oSavedFile = new RandomAccessFile(sName,"rw"); fUq #mkq}
this.nPos = nPos; h5v=h>c
oSavedFile.seek(nPos); m,rkKhXP
} 'W&ewZH_h
\23m*3"W
p@d_Ru
public synchronized int write(byte[] b,int nStart,int nLen) dvAz}3p0]
{ ^--8 cLB n
int n = -1; VLbbn
try{ (L W2S;-
oSavedFile.write(b,nStart,nLen); 4S* X=1
n = nLen; ~L_1&q^4!i
} @"aqnj>+
catch(IOException e) (De>k8
{ 3/,}&SX
e.printStackTrace (); `2M*?.vk
} }:]CXrdg>
EO/41O
YQR[0Y&e=
return n; ]na$n[T/I
} NBw{
4Q,|7@
@J'tPW<$
} j@/p: fk
@E"lN
/1xBZfrN
/* DjvPeX
**SiteInfoBean.java 59X XmVg
*/ Wo5%@C#M
package NetFox; H=mFc@fh
p?4,YV|#
*y|zF6
public class SiteInfoBean { 1c*;Lr.K
u Vo"_c w
Q&w"!N
private String sSiteURL; //Site's URL l.BiE<&
private String sFilePath; //Saved File's Path Ieh<|O,-C
private String sFileName; //Saved File's Name UsdMCJ&G
private int nSplitter; //Count of Splited Downloading File 5eM{>qr}
nL]eGC
Dnd
public SiteInfoBean() MieO1l
{//nSplitter的缺省值为5 $s"-r9@q
//default value of nSplitter is 5 V \/Qik{h
this("","","",5); $dsLU5]1o
} /RWD\u<l
fk\]wFj
mA^3?yj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a>,Zp*V(
{ 6!([Hu#= *
sSiteURL= sURL; E *782>
sFilePath = sPath; G\~?.s|^
sFileName = sName; zd{sw}
this.nSplitter = nSpiltter; _.I58r
dt/-0~U
.Y^pDR12
} &%u m#XE
C)QKodI
h\+8eeIl
public String getSSiteURL() Y3SV6""y/
{ 28 zZ3|Z3
return sSiteURL; uII! ?
} ^4et; F%
]&tcocq
j' b0sve|?
public void setSSiteURL(String value) {e0(M*u
{ z|zEsDh;
sSiteURL = value; #8y"1I=i&
} wn\R|'Rdz
v4Kf{9q#
gu&W:FY
public String getSFilePath() aq#F
{ 0IBQE
return sFilePath; UUF]45t>
} SWyJ`
SH O&:2
[&(~1C|C
public void setSFilePath(String value) m[BpV.s
{ HYv-5:B
sFilePath = value; R83PHM
} { _Y'%Ggh
]@}o"Td
$9u:Ox 2
public String getSFileName() }ktK*4<k
{ 3ug~m-_
return sFileName; _nSEp>]L
} >~tx8aI{
AtxC(gm 1
uuL(BUGt-
public void setSFileName(String value) 4 []!Km
{ ?yu@eo
sFileName = value; X1BqN+=@9
} mP?}h
yw1Xxwc
!sYZ1;WAO
public int getNSplitter() 6o*'Q8h
{ Nnoj6+b
return nSplitter; >ul&x!?@
} fB'Jo<C
fuWAw^&
u`Kc\BSn
public void setNSplitter(int nCount) *xpPD\{k
{ k L4#
nSplitter = nCount; !)05,6WQ
} Nz%pl!
} f 0~Z@\
2#cw_Ua
;";>7k/}
/* dP#7ev]'
**Utility.java -iFFXESVX
*/ "#iO{uMWb
package NetFox; b{X.lz0
K7/&~;ZwT
, 10+Sh
public class Utility { m}2hIhD9
Y^|15ek
-w'g0/fD
public Utility() ^;?w<9Y
{ $XKUw"%
`iEYq0}
{96NtR0Z
} cBHUa}:
U@(8)[?nxn
//线程睡眠 ucbtPTFYvr
public static void sleep(int nSecond) Z+4Mo*#
{ RusiCo!r
try{ -W:@3\{
Thread.sleep(nSecond); dN){w _
} VRHS 4
catch(Exception e) =w:H9uj6F
{ J|cw9u
e.printStackTrace (); &?gcnMg$,J
} !L_xcov!Y
} b0tbS[j
.RS
//日志 UA#=K+2
public static void log(String sMsg) f,BJb+0
{ B E#pHg
System.err.println(sMsg); j}8^gz]
} x26 sH5
E#kH>q@K`$
Ysi@wK-LnF
public static void log(int sMsg) lHu/pSu@k
{ s GrI%3[e"
System.err.println(sMsg); ~\%H0.P6
} HS1{4/
} 9g$fFO
`"$9L[>
= @FT$GQ
/* J,=^'K(
**TestMethod.java ^q<EnsY
*/ \;"S>dg
package NetFox; 0bGQO&s [
foI:`]2"*
cr^R9dv
public class TestMethod { V{rQ@7SE
/]nrxT
7 S%`]M4;
public TestMethod() Z,F1n/7
{ ///xx/weblogic60b2_win.exe ^;Yjs.bI`F
try{ g G|4+' t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "&mwrjn"T
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); XK(aH~7xme
SiteFileFetch fileFetch = new SiteFileFetch(bean); wJ7Fnj>u%
fileFetch.start(); i2\CDYP
} #|Je%t}~
catch(Exception e){e.printStackTrace ();} F+V[`w*k
?Y9VviC
Ge76/T%{Q
} #;'*W$Wk2
n$"BF\eM
_Aw-{HE'
public static void main(String[] args) QW%xwV?8
{ iyMoLZ5
new TestMethod(); o1Wf#Zq
} jgw+c3^R_
} {|Fn<&G
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