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)); uZo]8mV
} @&/s~3
for(int i=0;i<nEndPos.length-1;i++) qiF@7i
{ GGYX!=]~
nEndPos = nStartPos[i+1]; /F\>Z]
} kxt\{iy4
nEndPos[nEndPos.length-1] = nFileLength; HQ ELK
} l"2^S6vU
} WsG"x>1n
tg4LE?nv
fU\k?'x_
//启动子线程 TyxU6<>4J4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [flu|v
for(int i=0;i<nStartPos.length;i++) n23%[#,r
{ yf0vR%,\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ::^qy^n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iX0]g45o
nStartPos,nEndPos,i); lo IL{2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]{q-Y<{"
fileSplitterFetch.start(); x9FLr}e
} wdN>KS2!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OX#eLco
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p 02nd.R6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j\i;'t}8g
nEndPos = " + nFileLength); F)[XIY&2/
// fileSplitterFetch[nPos.length-1].start(); r_!{!i3B
-+j9X;h:
0{^l2?mgSb
//等待子线程结束 yhw:xg_;Kz
//int count = 0; 02]8|B(E90
//是否结束while循环 /h}wM6pg
boolean breakWhile = false; Y%n{`9=
46Y7HTwE
u`L!za7fi
while(!bStop) &CxyP_
{ &"~,V6,q
write_nPos(); HlOAo:8'
Utility.sleep(500); #2ZrdD"5kQ
breakWhile = true; n;S0fg
cAsSN.HFS
1%]{0P0?[
for(int i=0;i<nStartPos.length;i++) 4X(1
{ vMW-gk
if(!fileSplitterFetch.bDownOver) n{qa]3
{ :3E8`q~c1
breakWhile = false; U:etcnb4w>
break; ino7!T`
} )+Y\NO?O
} R"8})a gw
if(breakWhile) Wj
break; m\}\RnZu
.LGkr@P
)P(d66yq'u
//count++; q6m87O9
//if(count>4) 7y)|^4X2
// siteStop(); fO^EMy\
} v0H>iKh7
r,Y/4(.c7U
+gD)Yd
System.err.println("文件下载结束！"); b/D9P~cE
} &s6(3k
catch(Exception e){e.printStackTrace ();} *fuGVA
} A]~iuUHm
[u9S+:7"
+2k|g2
//获得文件长度 61eKGcjs:
public long getFileSize() ^JF_;~C
{ gYH:EuY,
int nFileLength = -1; s_Ge22BZ
try{ |0vHy7CE
URL url = new URL(siteInfoBean.getSSiteURL()); 'mY,>#sT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aBA#\eV
httpConnection.setRequestProperty("User-Agent","NetFox"); ~M9n<kmE
nF!_q;+Vp
zf!\wY"`
int responseCode=httpConnection.getResponseCode(); ;6&=]I
if(responseCode>=400) hz~CW-47
{ nD?M;XN
processErrorCode(responseCode); ^2?O+ =,F
return -2; //-2 represent access is error kvO`]>#;$?
} Wp9 2sm+
@*`UOgP7
/o06hy
String sHeader; $nd-[xV
51(`wo>LS
!+26a*P
for(int i=1;;i++) 'r?HL;,q
{ t%YX-@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E,yzy[gl
//Utility.log(in.readLine()); |9i/)LRXe
sHeader=httpConnection.getHeaderFieldKey(i); z&yb_A:>
if(sHeader!=null) !&:W1Jkp(
{ 8!fAv$g0
if(sHeader.equals("Content-Length")) G|Yp<W%o
{ :>-sITeY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CH_Dat>
break; G`JwAy r'
} iKEKk\j-w
} 2,QApW_Y
else ' ^L
break; K}*p(1$u
} 0~L8yMM
} $8ww]}K
catch(IOException e){e.printStackTrace ();} Q\>SF
catch(Exception e){e.printStackTrace ();} cM'[;u
d~bH!P
S$_Ts1Ge6
Utility.log(nFileLength); J3}C T
\]:NOmI^'
Fu$Gl$qV?%
return nFileLength; nsw8[pk
} n_NG~/x
]be2jQx3
V`&*%xgGR
//保存下载信息（文件指针位置） P##(V!YR
private void write_nPos() hnLgsz
{ 2X|jq4
try{ 7Z:l;%]K
output = new DataOutputStream(new FileOutputStream(tmpFile)); Evgq}3
output.writeInt(nStartPos.length); +A3\Hj&W
for(int i=0;i<nStartPos.length;i++) E0%Y%PQ**{
{ "YU~QOGx@
// output.writeLong(nPos); FrM~6A_
output.writeLong(fileSplitterFetch.nStartPos); (dnc7KrM
output.writeLong(fileSplitterFetch.nEndPos); y/*Tvb #TJ
} eeR@p$4i
output.close(); MBrVh6z>
} }(IDPaJ
catch(IOException e){e.printStackTrace ();} (j Q6~1
catch(Exception e){e.printStackTrace ();} e~[z]GLO%
} otVdx&%]
,'DrFlI
f;dU72]q+
//读取保存的下载信息（文件指针位置） qCT\rZU
private void read_nPos() }n8;A;axi
{ k"-#ox!
try{ m8A1^ R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); TTak[e&j3
int nCount = input.readInt(); nezbmpL4
nStartPos = new long[nCount]; UC$+&&rO
nEndPos = new long[nCount]; T1[ZrY'0
for(int i=0;i<nStartPos.length;i++) w:(7fu=
{ J~`%Nj5>
nStartPos = input.readLong(); 3`8xh9O
nEndPos = input.readLong(); wA&)y>n-
} HBGA lZ
input.close(); LZ dNG\-
} hvZR4|k>
catch(IOException e){e.printStackTrace ();} 7OHw/-j\
catch(Exception e){e.printStackTrace ();} 4'|:SyOm
} xM,(|p(
p[:%Ck"$7
a$&6a
private void processErrorCode(int nErrorCode) ?MB nnyo6
{ L#bQ`t
System.err.println("Error Code : " + nErrorCode); (fb\A6
} $oH,:x?}
Ux]@prAq
^<+heX
//停止文件下载 =LA@E&,j
public void siteStop() 8"^TWzg}L
{ uS,$P34^oy
bStop = true; T+!kRigN~P
for(int i=0;i<nStartPos.length;i++) i|'t!3I^m
fileSplitterFetch.splitterStop(); =1Jo-!{{
>Sah\u`
x*)O<K
} W{aNS@1
} A[a+,TN{
//负责部分文件的抓取 . %7A7a
**FileSplitterFetch.java 3/05ee;|
*/ @kymL8"2w
package NetFox; NE"fyX`
]aL}&GlHt
4F!d V;"Z(
import java.io.*; {*Pp^r
import java.net.*; =<xbE;,0
!CKUkoX
1fZ:^|\
public class FileSplitterFetch extends Thread { wYG0*!Vj
L~~Yh{<
l[k$O$jo
String sURL; //File URL ~yN,FpD
long nStartPos; //File Snippet Start Position ;wrgpP3
long nEndPos; //File Snippet End Position YvX I
int nThreadID; //Thread's ID *6tN o-)^
boolean bDownOver = false; //Downing is over 6Tnzg`0I
boolean bStop = false; //Stop identical UtN>6$u
FileAccessI fileAccessI = null; //File Access interface R3A^VE;qP
(z7#KJ1+Aw
@35shLs
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,vPF=wq
{ lH.2H
this.sURL = sURL; K2 2Xo<3
this.nStartPos = nStart; y rk#)@/m
this.nEndPos = nEnd; 2Fi*)\{
nThreadID = id; $!Tw`O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wQT'~'kL
} stPCw$@
FQ%mNowuj
~@lNBF
public void run() *bEsWeP
{ nmr>Aj8[
while(nStartPos < nEndPos && !bStop) CCV~nf
{ M %~kh"
;H lv
\BL9}5y
try{ e^yB9b
URL url = new URL(sURL); +zsya4r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eAMT72_
httpConnection.setRequestProperty("User-Agent","NetFox"); @d\F; o<
String sProperty = "bytes="+nStartPos+"-"; I?QKd@
httpConnection.setRequestProperty("RANGE",sProperty); @zbXG_J
Utility.log(sProperty); (&(f`c@I
a0R]hENC
@_{"ho
InputStream input = httpConnection.getInputStream(); fvDwg
//logResponseHead(httpConnection); c+JlM1p@
ry'(mM
!r<7]nwV
byte[] b = new byte[1024]; J5k%
int nRead; scdT/|(U$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E'Bt1u
{ 5WUrRQ?E
nStartPos += fileAccessI.write(b,0,nRead); tz,FK;8
//if(nThreadID == 1) {Fj`'0Xu;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (rJvE*
} {8' 5
c\Dv3bF
>L%%B-
Utility.log("Thread " + nThreadID + " is over!"); ]arP6iN+
bDownOver = true; i+;EuHf
//nPos = fileAccessI.write (b,0,nRead); )l=j,4nn
} ?Rdi"{.wI
catch(Exception e){e.printStackTrace ();} .NKN2
} y;;@T X
} yC[}gHv
<6@Db$-
>2a~hW|,
//打印回应的头信息 /W9=7&R0
public void logResponseHead(HttpURLConnection con) sdb#K?l
{ \21!NPXH2
for(int i=1;;i++) Z1Wra-g
{ -a3C3!!
String header=con.getHeaderFieldKey(i); Rh=h{O
if(header!=null) y3x_B@}BY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4 QWHGh"
Utility.log(header+" : "+con.getHeaderField(header)); 8:f(PN
else MStaP;|
break; HkrNt/]
} V{][{5SR
} j0J6ySlY
C-8@elZ1
8W{R&Z7aL
public void splitterStop() L(.5:&Y=`
{ -{dwLl_
bStop = true; s^cHR1^
} hQ9VcS6=gD
qg_=5s
m9r X
} IMj{n.y4
B9]KC i
7>#74oy
/* d2pVO]l YZ
**FileAccess.java >6c{CYuT
*//文件访问(定位，写) ;e+ErN`a.~
package NetFox; GE|V^_|i
import java.io.*; p?5zwdX+`
'2eggX%
./u3z|q1
public class FileAccessI implements Serializable{ % _N-:.S
|1#*`2j\=9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =m UtBD.;
RandomAccessFile oSavedFile; \]zHM.E1
long nPos; d+8Sypv^4*
F8q|$[nH
XLB7 E
public FileAccessI() throws IOException HZ/e^"cpM
{ L:7%Wdyh
this("",0); nBR4j?':i
} 5-*/wKjLz
ol-U%J
J%{>I
public FileAccessI(String sName,long nPos) throws IOException *&XOzaVU
{ i!(u4wTFF
oSavedFile = new RandomAccessFile(sName,"rw"); I=0`xF|4K-
this.nPos = nPos; fTMn
oSavedFile.seek(nPos); V3 2F
} Nzf tc
05Ak[OOU>
U&GSMjqg
public synchronized int write(byte[] b,int nStart,int nLen) 1GE[*$vuq
{ RGsgT^
int n = -1; 1 Qln|b8<
try{ Ko:<@h
oSavedFile.write(b,nStart,nLen); *jM]:GpyoU
n = nLen; ]De<'x}
} PKJw%.-
catch(IOException e) wt]onve}%
{ KSz;D+L\
e.printStackTrace (); lxf+$Z`~:
} vhvFBx0
g=n{G@*N
k..AP<hH
return n; a]]eQ(xQ
} T\q:
]Q$Sei5
JVydTvc
} |h%=a8
zncKd{Q\tP
TXdo,DPv7
/* 42M_ %l_
**SiteInfoBean.java 0Xb,ne 7
*/ %tB7 &%ut
package NetFox; tTOBKA89
AO, o|,#4F
:er(YWF:
public class SiteInfoBean { agt/;>q\~
/g$G G9
H-\Ym}BGu
private String sSiteURL; //Site's URL uP G\1
private String sFilePath; //Saved File's Path 0 30LT$&!
private String sFileName; //Saved File's Name o%7-<\qS
private int nSplitter; //Count of Splited Downloading File y4U|~\]
|M`'
e>6|# d
public SiteInfoBean() JR8|!Of@B
{//nSplitter的缺省值为5 JkhWLQ>o
//default value of nSplitter is 5 _B>'07D0
this("","","",5); 'Lq+ONX5
} auga`*
aq)g&.dw?
s_ t/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {n|ah{_p|
{ yts@cd`$
sSiteURL= sURL; elAWQEus
sFilePath = sPath; %N)B8A9kh
sFileName = sName; "4\k1H"_
this.nSplitter = nSpiltter; <rtKPlb//
/5)*epF+
9dq"x[
} BBM[Fy37!}
r1}^\C
?r KbL^2
public String getSSiteURL() &#L C'
{ D6Au)1y=&
return sSiteURL; vhPlH0
} VcGl8~#9
4j~q,#$LW
V:w%5'^3
public void setSSiteURL(String value) tPl 4'tW_
{ 0KnL{Cj
sSiteURL = value; <4+P37^~
} 9v_s_QkL2
~v%6*9
tPQ|znB|
public String getSFilePath() XHekz6_
{ QuqznYSY{
return sFilePath; lhHH|~t0
} 5]>*0#C S
p;>A:i
wn.~Dx
public void setSFilePath(String value) ]R_R`X?
{ /1MmOB
sFilePath = value; gYhY1Mym
} N2O *g`YC
K_;vqi^1^&
i}VF$XN
public String getSFileName() `wXK&R<`
{ :ZM9lBYh
return sFileName; iqvLu{
} I)rO|
&1$d`>fn
~f h
public void setSFileName(String value) 1ZI1+TDH
{ B W<Dmn
sFileName = value; sq!$+=1-X
} C3}:DIn"w
$DoR@2~y
#B;P4n3
public int getNSplitter() !l9{R8m>eJ
{ f`n4'dG
return nSplitter; I.n,TJoz4J
} $Z:O&sD{
C`hdj/!A
x~V[}4E%>
public void setNSplitter(int nCount) ;=y"Z^
{ ,WRm{v0f^
nSplitter = nCount; UGSZg|&6#*
} 2#>;cn\
} c_3B:F7
VHxBs
Am<5J,<uy
/* B?! L~J@p
**Utility.java C^L+R7
*/ e9o\qEm
package NetFox; <rBW6o7
e$Ksn_wEq
!;eE7xn&
public class Utility { F\ B/q
?{ N,&d
(`1io
public Utility() >v]^nJl
{ x4WCAqi/2
$G".PWc
1&|]8=pG7
} F\m^slsu7=
:W.H#@'(
//线程睡眠 }bb,Iib
public static void sleep(int nSecond) 3vY-;&
{ Lc{AB!Br
try{ 2_q/<8t
Thread.sleep(nSecond); 'Aq^z%|
} MgXZN{
catch(Exception e) x3q^}sj%
{ ]SQ+r*a
e.printStackTrace (); \Y4(+t=4
} 7hHID>,o9%
} "wgPPop
"t0^4=c+7
//日志 1SExlU
public static void log(String sMsg) Db|f"3rq?
{ {KG}m'lx
System.err.println(sMsg); \n{#r`T
} =-r"@2HBq
2R\K!e
K(+=V)'Dz
public static void log(int sMsg) \lbH
{ %Psg53N
System.err.println(sMsg); 1aAOT6h
} ),x0G*oebj
} LeCc`x,5
ctP+ECH
jr`swyg
/* &]TniQH
**TestMethod.java \rr"EAk]
*/ QRju9x
package NetFox; JN8Rh
|Yli~Qx
n*\o. :f
public class TestMethod { ntIR#fB
e|tx`yA
HM% +Y47a
public TestMethod() RvR.t"8
{ ///xx/weblogic60b2_win.exe PhAfEsD
try{ n*[ZS[I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kXL0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Mi.#x_
SiteFileFetch fileFetch = new SiteFileFetch(bean); n.l#(`($4
fileFetch.start(); 2bCfY\k
} q7CLxv &QG
catch(Exception e){e.printStackTrace ();} }XUL\6U
LVUA"'6V
f/dJRcDl<
} ozY$}|sjDT
'-"[>`[q
Tf#Op v)
public static void main(String[] args) uihH")Mo
{ kI"9T`owR
new TestMethod(); jGouwta
} Kb]}p
} ICz:>4M-dn
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