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)); 0ge"ISK
} [&_7w\m
for(int i=0;i<nEndPos.length-1;i++) YmrrZ&]q
{ d=`a-R0
nEndPos = nStartPos[i+1]; 968<yO]
} z7vc|Z|
nEndPos[nEndPos.length-1] = nFileLength; 5j8aMnvs
} / .wO<l=
} @nC][gNv
b 7XTOB_HO
PK C}!>2
//启动子线程 rJjNoY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; UL{+mp
for(int i=0;i<nStartPos.length;i++) 0+-"9pED>E
{ 1c5+XCr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +3>)r{#k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OC?a[^hB^)
nStartPos,nEndPos,i); FUt{-H!<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \d'>Ky;GD
fileSplitterFetch.start(); x;^DlyyYU
} Y ~TR`y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `w&A;fR!H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <{ER#}b:O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lEZODc+%Y
nEndPos = " + nFileLength); PO*;V<^
// fileSplitterFetch[nPos.length-1].start(); k.."_4
@AB}r1E2
CpE LLA<
//等待子线程结束 M]Kxg;
//int count = 0; tPp9=e2[s
//是否结束while循环 :VkuK@Th`
boolean breakWhile = false; ;[qA?<GJ
8+* 1s7{
v}cTS@0
while(!bStop) ?\Bm>p%+
{ p*NKM} ]I
write_nPos(); c-`'`L^J
Utility.sleep(500); 0~a9gBG
breakWhile = true; k)3b0T@b
{4F=].!
g=gM}`X%
for(int i=0;i<nStartPos.length;i++) Exb?eHO
{ (]@yDb4
if(!fileSplitterFetch.bDownOver) @u>:(9bp
{ (DIMt-wz
breakWhile = false; +vr|J:
break; .OM^@V~T
} 4)Bk:K
} We`6# \Z X
if(breakWhile) 7DZZdH$Fm
break; EXF|;@-"
]lqe,>
ixvF`S9
//count++; g`Kh&|GU
//if(count>4) ` t6|09e
// siteStop(); [mcER4]}
} 0Yk$f1g
yC:C
^KF%Z2:$
System.err.println("文件下载结束！"); @e#{Sm
} tqFE>ojlI
catch(Exception e){e.printStackTrace ();} r}\m%(i
} 3/{,}F$
oypF0?!m
NZu2D
//获得文件长度 H3xMoSs
public long getFileSize() u2E}DhV
{ vWH)W?2
int nFileLength = -1; D_Zt:tzO
try{ Yn_v'Os2
URL url = new URL(siteInfoBean.getSSiteURL()); jtv<{7a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X:>,3[hx|
httpConnection.setRequestProperty("User-Agent","NetFox"); 1YtbV3
f q&(&(|
yog(
int responseCode=httpConnection.getResponseCode(); J$^"cCMr
if(responseCode>=400) h( DmSW
{ N|2PW ~,
processErrorCode(responseCode); &5y|Q?
return -2; //-2 represent access is error adn2&7H
} `'E(L&
zHX7%x,Cq
h]vuBHJ}
String sHeader; "oT&KW
mVd%sWD
K2qKkV@
for(int i=1;;i++) 8b:GyC5L
{ n`X}&(O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `]I p`_{
//Utility.log(in.readLine()); r>lo@e0G
sHeader=httpConnection.getHeaderFieldKey(i); Ew )1O9f
if(sHeader!=null) *5KDu$'(e
{ Rd;^ fBx
if(sHeader.equals("Content-Length")) B'-n ^';
{ 8\S$iGd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =/+f3
break; 8dLK5"_3
} Ez+8B|0P
} NydF'N_1
else yIu_DFq%
break; Q"s]<MtdS
} Y#zHw<<E
} RZ0+Uu/J
catch(IOException e){e.printStackTrace ();} XD%GNZ
catch(Exception e){e.printStackTrace ();} Q%QIr
bMB@${i}
?$6(@>`f&t
Utility.log(nFileLength); ]1s6=
Xd@ d$
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return nFileLength; /^9=2~b
} ,: Ij@u>)
6Zx)L|B
)@],0yL
//保存下载信息（文件指针位置） f<;eNN
private void write_nPos() >{{0odBF
{ !8I80:e_~
try{ Hyb_>n
output = new DataOutputStream(new FileOutputStream(tmpFile)); fp?/Dg"49.
output.writeInt(nStartPos.length); R9-Uoc/
for(int i=0;i<nStartPos.length;i++) 9*S9~
{ 5i-VnG
// output.writeLong(nPos); IOY<'t+
output.writeLong(fileSplitterFetch.nStartPos); *&~(>gNF,
output.writeLong(fileSplitterFetch.nEndPos); K2gF;(
} pwVaSnre`
output.close(); 39bw,lRPV
} @2~;)*
catch(IOException e){e.printStackTrace ();} M Al4g+es
catch(Exception e){e.printStackTrace ();} Eih6?Lpu
} PU-L,]K
! Q8y]9O
L5wR4Ue)
//读取保存的下载信息（文件指针位置） P@0J!
private void read_nPos() GK[9Cm"v
{ pB0 SCS*
try{ OCu/w1bc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EGzlRSgO
int nCount = input.readInt(); fLZ99?J
nStartPos = new long[nCount]; n^Q-K}!T/
nEndPos = new long[nCount]; >J_(~{-sNG
for(int i=0;i<nStartPos.length;i++) s;#,c(
{ S])*LUi
nStartPos = input.readLong(); K$wxiGg8P
nEndPos = input.readLong(); 6GoQJ
} @CS%=tE}U
input.close(); #kgLdd"
} 0lU pil
catch(IOException e){e.printStackTrace ();} \s6VOR/
catch(Exception e){e.printStackTrace ();} *-&+;|mM
} ~!P&LZ
F{E`MK~f_
JvF0s}#4
private void processErrorCode(int nErrorCode) = Atyy
{ _FkH;MGWS
System.err.println("Error Code : " + nErrorCode); IM_SZs
} pp+z5
_adW>-wQ!d
$mxl&Qr>Q;
//停止文件下载 $ncP#6
public void siteStop() _FCg5F2U
{ 2>g!+p Ox
bStop = true; MaZVGrcC
for(int i=0;i<nStartPos.length;i++) d wku6lCk
fileSplitterFetch.splitterStop(); Q!(qb
Q"K`~QF"
Fr#QM0--B
} C3KAQU
} n2Y a'YF
//负责部分文件的抓取 y>c Yw!
**FileSplitterFetch.java Qx8O&C?Ti
*/ H-3*},9
package NetFox; l)f 2T@bHl
bZ}T;!U?I
jxZ_-1
import java.io.*; }Vfc;2
import java.net.*; @xr}(.
jP.dQj^j&
=3=8oFx8
public class FileSplitterFetch extends Thread { C_&ZQlgQ
tlgg~MViS
^*F'[!. p
String sURL; //File URL 71Y3.1+
long nStartPos; //File Snippet Start Position _ Gkb[H&RZ
long nEndPos; //File Snippet End Position ;Q<2Y#
int nThreadID; //Thread's ID v!#koqd1y.
boolean bDownOver = false; //Downing is over D2f~*!vEnA
boolean bStop = false; //Stop identical bp'\nso/
FileAccessI fileAccessI = null; //File Access interface QwLSL<.
|P-kyY34
cA~bH 6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException FAq9G-\B
{ MADt$_
this.sURL = sURL; {d%hkbN+{
this.nStartPos = nStart; \*Z:w3;r
this.nEndPos = nEnd; 5k;}I|rg%
nThreadID = id; n`D-?]*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m,Mg
} _pkmHj(
A27!I+M
7)BK&kpVr
public void run() c1<jY~U
{ Sc:)H2k`$
while(nStartPos < nEndPos && !bStop) 1cV0TUrz
{ :H/Rhx=
$PMD$c
REPI>-|
try{ =<Ss&p>
URL url = new URL(sURL); EQX?Zs?C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q&esI
httpConnection.setRequestProperty("User-Agent","NetFox"); >fp_$bjd
String sProperty = "bytes="+nStartPos+"-"; VqS1n
httpConnection.setRequestProperty("RANGE",sProperty); 6%&DJBU!
Utility.log(sProperty); awSi0*d~
J!H)[~2/
_xM3c&VeG
InputStream input = httpConnection.getInputStream(); 4{%-r[C9k
//logResponseHead(httpConnection); o`nJJ:Cxq-
]3 76F7
X]s="^
byte[] b = new byte[1024]; :`S\p[5
int nRead; 1_>w|6;e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7|<-rjz^
{ o),@I#fM
nStartPos += fileAccessI.write(b,0,nRead); X(Lz&fkd
//if(nThreadID == 1) 1%7zCM0s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ODKS6E1{
} :JK+V2B$H
Q@rlqWgU ~
!*}E
Utility.log("Thread " + nThreadID + " is over!"); >[g.8'hI
bDownOver = true; ,<;.'r
//nPos = fileAccessI.write (b,0,nRead); Ll`nO;h
} \F<C$cys\
catch(Exception e){e.printStackTrace ();} Wv30;7~
} nbBox,zW
} y27MG
+u3vKzD
70Ei<
//打印回应的头信息 @1V?94T1
public void logResponseHead(HttpURLConnection con) v>5TTL~?
{ ~zFwSF
for(int i=1;;i++) c1 1?Kq
{ \7Fp@ .S3
String header=con.getHeaderFieldKey(i); 5Z[HlN|-!
if(header!=null) $SU<KNMZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 64SRW8AH
Utility.log(header+" : "+con.getHeaderField(header)); E#\'$@8j
else NYPjN9L
break; &7KX`%K"D
} ~uuM0POo
} ZSn6JV'g
z=TuUl@
v&xhS yZ
public void splitterStop() zI_pP?4;.q
{ SA~oGgk=P
bStop = true; L/,M@1@R
} Kk>va->R
#^w8Y'{?
vZIx>
} :~~\{fm
=9A!5
4qyPjAG
/* QLZ%m$Z
**FileAccess.java N._^\FRyn
*//文件访问(定位，写) "SpsSQ
package NetFox; [L?WM>]%
import java.io.*; VQbKrnX
/Mw0<#
Gk)6ljL
public class FileAccessI implements Serializable{ g?>
Olr'n% }
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KXcE@q9
RandomAccessFile oSavedFile; !{XVaQ?x
long nPos; cB2~W%H
F#|mN0op
Pa/2])w
public FileAccessI() throws IOException Zrq\:KxX
{ nDXy$f8
this("",0); Suk;##I
} |q 0iX2W
qO>A6
rM20Y(|
public FileAccessI(String sName,long nPos) throws IOException }5y]kn
{ =l%|W[OO
oSavedFile = new RandomAccessFile(sName,"rw"); D/tFN+|P
this.nPos = nPos; cFoeyI#v
oSavedFile.seek(nPos); bJL,pe+u
} /%P,y+<}iG
\m+;^_;5GW
hD7Lgi-N)W
public synchronized int write(byte[] b,int nStart,int nLen) f1I/aRV:+
{ da$ErN'{
int n = -1; u7 {R; QKw
try{ KvlLcE~`o
oSavedFile.write(b,nStart,nLen); !8o;~PPVl
n = nLen; 1P/4,D@
} +P=I4-?eX
catch(IOException e) qhNYQ/uS
{ /z4n?&tM
e.printStackTrace (); 8[u$CTl7a
} m"vWu0/#
uD4$<rSHb
l6-%)6u>
return n; _@sSVh$+
} xUDXg*
<X]dR 6FT
oTf^-29d
} A )xfO-
Uy$?B"Z
0lpUn74F
/* s5oU
**SiteInfoBean.java yu=(m~KX
*/ f6%7:B d
package NetFox; )IGx3+I ,
S{JBV@@tC
-nk0Q_7N
public class SiteInfoBean { Og"\@n
:JzJ(q/
''B}^yKEW
private String sSiteURL; //Site's URL kDWvjT
private String sFilePath; //Saved File's Path n<MreKixE
private String sFileName; //Saved File's Name ,/..f!bp
private int nSplitter; //Count of Splited Downloading File sT>l ?L
%>,Kd6bdg
rq^VOK|L
public SiteInfoBean() s@|TQ9e |j
{//nSplitter的缺省值为5 HeM-
//default value of nSplitter is 5 'dcO-A:>
this("","","",5); 01o,9_|FL
} |3 v+&eVi
3NgyF[c
3!u:*ibt
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6g'+1%O
{ ]}BT'fky#
sSiteURL= sURL; t+n+_X
sFilePath = sPath; .q9i10C
sFileName = sName; F vHd`
this.nSplitter = nSpiltter; H)i%\7F5
PYW>
q%MLj./?[
} $(;0;!t.
,%,.c^-
-\}Ix>
public String getSSiteURL() i,y7R?-K
{ KgEfhO$W
return sSiteURL; ;Y`k-R:E6A
} X8(WsN
mjbV^^>
f=nVK4DuZ
public void setSSiteURL(String value) ~9dAoILrl
{ a9TKp$LP`
sSiteURL = value; sQ%gf
} BY??X=
n;*W#c
3+iQct[
public String getSFilePath() S$i3/t
{ w-?Cg8bq<
return sFilePath; x-@6U
} ZVz`-hB
f}+8m .g2
~bLhI
public void setSFilePath(String value) `r.
{ Mt+ggF.
sFilePath = value; XnV$}T:?X
} 3ypf_]<
firiYL"=44
Be2yS]U
public String getSFileName() BI0 A0
{ Qb&gKQtt@
return sFileName; VHTr;(]hk
} +v"%@lC};
q<wQ/m
1<3!
public void setSFileName(String value) v6+<F;G3y>
{ wM&WR2
sFileName = value; ?K^~(D8(
} 2^=.jML[
$nW^Gqwj]1
pN7 v7rs
public int getNSplitter() 1U~yu&
{ ~QE-$;
return nSplitter; ;n=A245W\
} ob"yz}
_hs\"W
Y!lc/[8
public void setNSplitter(int nCount) 5 _ a-nWQ
{ j-wz7B
nSplitter = nCount; JM Ikr9/$
} -XARew
} + +G%~)S:
/a:L"7z
XpibI3:<
/* xzTF| Z\
**Utility.java qn|~z@"
*/ nV&v@g4Tt
package NetFox; rty&\u@}
vP{;'R
txXt<]N
public class Utility { b#E!wMClS
+K03yphZr
`d.4L.],
public Utility() LjMhPzCp
{ mY,t]#^m7
#~`]eM5`J
keL!;q|r-)
} ,7|Wf %X
I6Mr[#*
//线程睡眠 UIi`bbJ
public static void sleep(int nSecond) >PMLjXK
{ *IBCThj
try{ k>q}: J9V
Thread.sleep(nSecond); F5FzT^
} qI#ow_lL#
catch(Exception e) uV+.(sjH
{ %t<ba[9F
e.printStackTrace (); UV8K$n<
} ZMI vzQYI
} N"rZK/@}
dt|f4XWF
//日志 ~6-6aYhe
public static void log(String sMsg) qb1[-H
{ {kp^@
System.err.println(sMsg); %e'Z.vm
} , 1`-u$
![a~y`<K,
rYwUD7ip
public static void log(int sMsg) '`fz|.|cbB
{ JypXQC}~
System.err.println(sMsg); j: /cJt
} N"q C-h
} e3b|z.^8
dw]wQ\4B
l9X\\uG&
/* T&PLvyBL
**TestMethod.java |8YP8o
*/ 1xE*quhrh
package NetFox; 8'6$t@oT9w
Jh)K0>R
aj)?P
public class TestMethod { a#o6Nv
N"wp2w
%1jApCJ
public TestMethod() fK{[=xMr@
{ ///xx/weblogic60b2_win.exe JDy;Jb
try{ I~.d/!>Z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <OC|z3na_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .&Ok53]b
SiteFileFetch fileFetch = new SiteFileFetch(bean); xRU ~hQ
fileFetch.start(); 4%L-3Ij
} KGoHn6jM
catch(Exception e){e.printStackTrace ();} l`A4)8Y@
Lb} cjI:
1-bQ ( -
} Jf{ M[ z
@*rED6zH
b[_${in:
public static void main(String[] args) 5};$>47m
{ .A2u7*h&
new TestMethod(); \<R.F
} _cW6H B^j
} -d8||X[
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