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)); Ove<mFI\
} l|/ep:x8
for(int i=0;i<nEndPos.length-1;i++) 7s/u(~d)
{ .@(6Y<dN
nEndPos = nStartPos[i+1]; Y"~gw~7OD
} H,DM1Z9rz
nEndPos[nEndPos.length-1] = nFileLength; ~F4fFQ-yy
} E~]R2!9
} qAn!RkA
pi Z[Y 5OE
OW3sS+y
//启动子线程 w2 a1mU/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \HKxh:F'
for(int i=0;i<nStartPos.length;i++) Y0x%sz5
{ 5Ow[~p"l<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `8AR_7i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hp#W9@NR
nStartPos,nEndPos,i); 8n'B6hi
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (Tn- >).AO
fileSplitterFetch.start(); do*EKo
} wN;^[F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N'^&\@)xiU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hWD;jR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IFF92VD&
nEndPos = " + nFileLength); Hea;?4Vg
// fileSplitterFetch[nPos.length-1].start(); | N[<x@
g/P+ZXJ
-(
//等待子线程结束 ;_rF;9z9
//int count = 0; $wo?!gt
//是否结束while循环 Nv(9N-9r
boolean breakWhile = false; ~8GFQ ph
)%`^xR
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while(!bStop) l|kSsP:GO
{ FFu9&8Y
write_nPos(); d-k%{eBV
Utility.sleep(500); SKkUU^\#R`
breakWhile = true; j`~Ms>
kQEy#JQmB
KwPOO{4]g
for(int i=0;i<nStartPos.length;i++) 7R6ry(6N
{ E`?3PA8
if(!fileSplitterFetch.bDownOver) [co% :xJu
{ n/+.s(7c
breakWhile = false; mj9 <%P
break; }+C2I
} 4lKq{X5<
} ?QFpv#4
if(breakWhile) [n \2
break; xa<UM5eI
n)^i/ nXb'
uI1q>[
//count++; `< xn8h9p
//if(count>4) 3HcQ(+Z
// siteStop(); b:tob0TB
} Zc W:6po>
BT}!W`
!,6c ~ w
System.err.println("文件下载结束！"); {(r`k;fB
} FB{KH .
catch(Exception e){e.printStackTrace ();} -OapVac
} vb<oi&X
Y8-86 *zC
*X+79vG:
//获得文件长度 Rm255zp
public long getFileSize() -uMSe~
{ 3|'>`!hb
int nFileLength = -1; X voo=
try{ vgfcCcZ_iZ
URL url = new URL(siteInfoBean.getSSiteURL()); `f*Q$Ulqx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q9Kve3u-i
httpConnection.setRequestProperty("User-Agent","NetFox"); mi,E-
G!>z;5KuS
;/r1}tl+3>
int responseCode=httpConnection.getResponseCode(); 19E8'@
if(responseCode>=400) tt0f-:#
{ apg=-^L'
processErrorCode(responseCode); HY&aV2|A1
return -2; //-2 represent access is error $}>+kHoT{
} }bdmomV
W-?()dX{
E5I"%9X0H
String sHeader; ms*(9l.hOK
I%sFqh>
_'{_gei_P
for(int i=1;;i++) amOnqH-(
{ :,'wVS8"]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); BG6B:
//Utility.log(in.readLine()); OY;*zk
sHeader=httpConnection.getHeaderFieldKey(i); AiEd!u.
if(sHeader!=null) ~Y|*`C_)
{ @mw5~+
if(sHeader.equals("Content-Length")) DU5c=rxW
{ [AYOYENp-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k1{K*O$e
break; [lWQ'DZ
} lDYyqG4
} VF?<{F
else Y }$/e
break; ow_W%I=6
} =&ks)MH-
} ;<Ar=?
catch(IOException e){e.printStackTrace ();} Jk7|{W\OA
catch(Exception e){e.printStackTrace ();} {`LU+
M>~Drul
`$,GzS(
Utility.log(nFileLength); y9q8i(E0
[d(U38BI
nbm&wa[
return nFileLength; `6lr4Kk @R
} V^3L3|k
r'^Hg/Jzt
G,o6292hj
//保存下载信息（文件指针位置） * w?N{.
private void write_nPos() kYG/@7f/
{ jQ2Ot<
try{ gtk7)Uh
output = new DataOutputStream(new FileOutputStream(tmpFile)); e1%/26\
output.writeInt(nStartPos.length); 5*lT.
for(int i=0;i<nStartPos.length;i++) >O*IQ[r-
{ CE#gfP
// output.writeLong(nPos); 8u6:=fxb
output.writeLong(fileSplitterFetch.nStartPos); VH9dleZ
output.writeLong(fileSplitterFetch.nEndPos); /{+y2.{j
} D8Ykg >B;&
output.close(); 95 ;x=ju
} $ M`hh{ -
catch(IOException e){e.printStackTrace ();} M?Dfu .t
catch(Exception e){e.printStackTrace ();} DI:]GED"=
} QZ6D7tUc8
pR(jglm7-
_FH`pv
//读取保存的下载信息（文件指针位置） B8f8w)m
private void read_nPos() xF;kTBRi
{ _P0T)-X\(
try{ $*e2YQdLo
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B* ?]H*K
int nCount = input.readInt(); sH{4Y-J
nStartPos = new long[nCount]; 1_9<3,7
nEndPos = new long[nCount]; j(m.$:
for(int i=0;i<nStartPos.length;i++) 9^oKtkoDZ
{ <0b)YJb4M
nStartPos = input.readLong(); c~z82iXNO
nEndPos = input.readLong(); l`oZ)?ur
} )bS yB29S
input.close(); ~Sj9GxTe
} ?[@J8
catch(IOException e){e.printStackTrace ();} f .Q\Z'S^
catch(Exception e){e.printStackTrace ();} j[`j9mM8
} n^Hm;BiE#
NQBpX
&e @2
private void processErrorCode(int nErrorCode) hs^zTZ_
{ d,+Hd2o^X
System.err.println("Error Code : " + nErrorCode); B2>H_dmQ
} ;LcZ`1
0z1ifg&
U'H$`$Ov
//停止文件下载 %j.0G`x9 +
public void siteStop() t{xf:~B
{ zk$FkbX
bStop = true; OI|[roMK
for(int i=0;i<nStartPos.length;i++) b$N2z
fileSplitterFetch.splitterStop(); K"|l@Q[
A)bWcB}U
i3tg6o4C
} GeyvId03H
} Ag9vU7
//负责部分文件的抓取 7j@Hs[ *
**FileSplitterFetch.java t|g4m[kr
*/ f(/lLgI(
package NetFox; 6 Q%jA7
fObg3S92
v- 2:(IV
import java.io.*; nV"~-On
import java.net.*; e>6y%v;
((H^2KJn
|XQIfW]A
public class FileSplitterFetch extends Thread { 'GNK"XA^
+ieY:H[
uGwm r
String sURL; //File URL 6a[}'/
long nStartPos; //File Snippet Start Position +O8%Hm
long nEndPos; //File Snippet End Position u_@f$
int nThreadID; //Thread's ID CDsSrKhx
boolean bDownOver = false; //Downing is over ,]bhyp
boolean bStop = false; //Stop identical :ci5r;^
FileAccessI fileAccessI = null; //File Access interface \hTm)-FP
m8A#~i .
6eLR2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %Qmn-uZ
{ ;D3C>7y
this.sURL = sURL; gwLf'
this.nStartPos = nStart; YmL06<Mh
this.nEndPos = nEnd; NP0\i1P>.?
nThreadID = id; Px4)>/ z,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i6^twK)j
} `g(Y*uCp
U;YC}r
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public void run() {#ZlM
{ *:Y%HAy*
while(nStartPos < nEndPos && !bStop) 8[a=OP
{ <^VJy5>
[)H&'5 +F
Ur9?Td'*>
try{ D9<!mH
URL url = new URL(sURL); :*I#n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y\D!/T
httpConnection.setRequestProperty("User-Agent","NetFox"); n`#tKwWHYx
String sProperty = "bytes="+nStartPos+"-"; N(;1o.~
httpConnection.setRequestProperty("RANGE",sProperty); ,vr? 2k
Utility.log(sProperty); ?:vv50
RiDJ> 6S
.CL[_;}
InputStream input = httpConnection.getInputStream(); QA< Rhv,
//logResponseHead(httpConnection); h{CL{>d
=#;3Q~:Jl^
\K5DOM "#
byte[] b = new byte[1024]; 8L,5Q9 $
int nRead; MV5_L3M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )F}F_Y
{ Lb!Fcf|h
nStartPos += fileAccessI.write(b,0,nRead); X$HIVxyq2
//if(nThreadID == 1) MX$0Op
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !=pn77`g>
} C].iCxn
3DzMB?I
)Q=_0;#;k
Utility.log("Thread " + nThreadID + " is over!"); b,5~b&<h
bDownOver = true; .8@$\ZRP
//nPos = fileAccessI.write (b,0,nRead); (jnQ -
} D[4u+g?[}>
catch(Exception e){e.printStackTrace ();} r)lEofX,g+
} Bn^0^J-
} TITKj?*o
L9r8BK;
J*r*X.
//打印回应的头信息 ?Y$JWEPJ
public void logResponseHead(HttpURLConnection con) ?iw!OoZ`
{ P0SQr?W
for(int i=1;;i++) \MA+f~)9
{ VQ(jpns5
String header=con.getHeaderFieldKey(i); gT3_RUF
if(header!=null) };mA^xO]j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Vp#JS3Y
Utility.log(header+" : "+con.getHeaderField(header)); E-4b[xNj*+
else 6hw=
break; /sUYU(3
} Ghu#XJB?
} h`]Iy
u__9Z:+
s(5Y
public void splitterStop() ]GMe\n
{ jfP*"uUK
bStop = true; rxe>}ZO
} aI%g2q0f
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4qO+_!x{)
} 6w*dKInG[-
ot,jp|N>f~
QCD.YFM
/* EOIN^4V"
**FileAccess.java cbNTj$'b2u
*//文件访问(定位，写) q]\:P.x!>
package NetFox; fX(3H1$"
import java.io.*; {'NZ.
ls_'')yp
{}>0e:51
public class FileAccessI implements Serializable{ Lco~,OE
Qk0R a_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V39g,=`b%
RandomAccessFile oSavedFile; ?[VM6- &
long nPos; &c`nR<
&SIq2>QA
dV*]f$wQ
public FileAccessI() throws IOException Gk. ruQW"
{ |!1Y*|Q%s
this("",0); (jnzT=y
} [/PR\'|
")_|69 VX
=qoWCmg"&
public FileAccessI(String sName,long nPos) throws IOException ls?~+\Jb
{ 3oBtP<yG.
oSavedFile = new RandomAccessFile(sName,"rw"); $'0u|Xy`
this.nPos = nPos; %r<rcY
oSavedFile.seek(nPos); NC8t) X7
} vV'EZ?
9?A)n4b;
ko5@qNq
public synchronized int write(byte[] b,int nStart,int nLen) #Z}Rfk(~
{ [8.c8-lZ^
int n = -1; fsmN)_T
try{ >Y&N8PHD
oSavedFile.write(b,nStart,nLen); wc0jhHZO ?
n = nLen; IrR7"`.i
} V8e>l[tH
catch(IOException e) P]<4R:yb
{ G[B=>Cy
e.printStackTrace (); V("{)0~O
} T!-\@PB !
@*F"Q1 wI
Vmc5IPd{\
return n; hv)x=e<
} 00<cYy
Y_Eb'*PY
wGU*:k7p
} Hj'xAtx5
_ftI*ni:<
\K_ET> !
/* z(o,m3@v
**SiteInfoBean.java O ~(pg
*/ !ds"9w
package NetFox; 1;d$#j
8a&:6Zuo
Zvhsyz|
public class SiteInfoBean { JBD7h5|Lc
UN7EF/!Zz
zUDg&-J3
private String sSiteURL; //Site's URL V@\gS"Tu
private String sFilePath; //Saved File's Path 'QG xd!4
private String sFileName; //Saved File's Name SIe="YG]<
private int nSplitter; //Count of Splited Downloading File /;{P}-H`ei
g(nPQOs$u
9Q -HeXvR
public SiteInfoBean() 8{Q<N%Jnu
{//nSplitter的缺省值为5 E^Y#&skXp3
//default value of nSplitter is 5 #:%&x@@c3P
this("","","",5); > pgX^
} jy7\+i
MtM%{=&_
y9_V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~aw.(A?MI
{ ]~844Jp
sSiteURL= sURL; ioaU*%
sFilePath = sPath; OHv[#xGuV?
sFileName = sName; 1ofKt=|=
this.nSplitter = nSpiltter; |o,YCzy|5
SD#]$v
K*\'.~[6
} 909?_v
6.FY0.i
MU>k,:[
public String getSSiteURL() "-y-iJ
{ < |e,05aM
return sSiteURL; p$SX
} r)qnl9?;`]
JgG$?n\
agkA}O
public void setSSiteURL(String value) 5NBV[EP
{ U6=..K!q
sSiteURL = value; M-\Y"]sW
} ]5BX:%
sPd Gw~{
,"2s`YC
public String getSFilePath() siXr;/n"
{ :#2Bw]z&z
return sFilePath; eeIhed9
} /{|EAd{
A+HF@Uw}^
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public void setSFilePath(String value) Z/Eb:
{ <wZQc
sFilePath = value; =5aDM\L$&
} soPLA68
]&?Y~"{cD
3WN`y8l
public String getSFileName() Kfm5i Q
{ F8hw#!Aq
return sFileName; XttqOf
} KuWWUjCE
-7m:91x
!GOM5z,
public void setSFileName(String value) EJ@?h(O
{ c/Qt Ot
sFileName = value; J~=n`pW
} >oea{u
s~X+*@.
yphS'AG
public int getNSplitter() ^L0d/,ik
{ AoY-\E
return nSplitter; X7[^s $VK
} YNYx>Ue
og4UhP^UET
5>VY LI
public void setNSplitter(int nCount) dG@"!!,
{ `{,Dy!rL
nSplitter = nCount; @|LBn6q
} =,%CLS,6w
} R,)}>X|<
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'[J<=2&
/* Nb?w|Ne(T
**Utility.java u83J@nDQ
*/ P-`M
package NetFox; "@evXql3`
OQ8 bI=?[x
hbU+Usx
public class Utility { r~+\ Y"rM
|\_^B
rX*H)3F
public Utility() ;g6M%;1-
{ wg ^sGKN
b'P eH\h{
=PUt&`1.a
} 3VuW#m#j
+${D
//线程睡眠 /V=24\1Ky
public static void sleep(int nSecond) 6}75iIKi
{ JBZUv
try{ *o-.6OxZ$
Thread.sleep(nSecond); gWrgnlq
} RZ6xdq}>
catch(Exception e) yvgrIdEP
{ :]rJGgK#
e.printStackTrace (); 3VI4X
} Q s.pGi0W
} [(o7$i29|%
zR `EU,
//日志 ~)qtply
public static void log(String sMsg) 7~&/_3
{ PN0VQ/..
System.err.println(sMsg); 1J6,]M
} .P.z B}0=
tyfTU5"x
1mfs4
public static void log(int sMsg) U`,0]"Qk
{ FW) x:2BG
System.err.println(sMsg); m.px>v-
} _FXZm50\g{
} ]E_h
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l_EM8pL,f
/* oHMo>*?
**TestMethod.java qzI&<4
*/ $KUos+%
package NetFox; 0ge$ p,
\=+b}mKV m
)foq),2
public class TestMethod { hdnTXs@z
"8~:[G#
:[\v
public TestMethod() M~WijDj
{ ///xx/weblogic60b2_win.exe |l&vkRrN
try{ -:Fe7c
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SF}<{x_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U7doU'V/
SiteFileFetch fileFetch = new SiteFileFetch(bean); i:rFQ8I
fileFetch.start(); )'/|)
} YFE&r
catch(Exception e){e.printStackTrace ();} N>Eqj>G
`(v='$6}
O=v#{[
} "VkTY|a
tniDF>Rb
lZyG)0t,g
public static void main(String[] args) E Q4KV
{ &LF` W
new TestMethod(); "]oO{'1X
} AX?fuDLs
} I8+~ &V}
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