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)); ybfNG@N*
} &B[$l`1
for(int i=0;i<nEndPos.length-1;i++) ?QZ\KY
{ 9c<lFZb;
nEndPos = nStartPos[i+1]; z"R-Sme
} q[r|p"TGov
nEndPos[nEndPos.length-1] = nFileLength; 5pz%DhjLo
} 4e9mN~
} D\>CEBt
S&9{kt|BI
i_V~SC`
//启动子线程 ^;N+"oq!y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e1K,4Bq
for(int i=0;i<nStartPos.length;i++) 8JGt|,
{ .0nL;o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R}BHRmSQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'AHI;Z~Gk
nStartPos,nEndPos,i); p9Ks=\yvL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7` &K=( .
fileSplitterFetch.start(); m"NZ;*d'
} |nB2X;K5~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \DpXs[1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :v=Yo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", z6$W@-Vd
nEndPos = " + nFileLength); ?-Fp rC
// fileSplitterFetch[nPos.length-1].start(); ?~;G)5
~[Mm0L}8
kpcIU7|e
//等待子线程结束 GKSfr8US4
//int count = 0; 8 yQjB-,#
//是否结束while循环 YX,y7Uhn
boolean breakWhile = false; crUt8L-B4
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lQY?!oj&q
while(!bStop) 5nQ*%u\$Z
{ @MS;qoc
write_nPos(); V`=#j[gX)=
Utility.sleep(500); h]&8hl_'m
breakWhile = true; xn}sh[<:P
Av]<[ F/
0 @~[SXR
for(int i=0;i<nStartPos.length;i++) A2!7a}*1(
{ \-gZ_>)
if(!fileSplitterFetch.bDownOver) 1W;q(#q
{ Z25^+)uf*U
breakWhile = false; pS;jrq I#
break; 1 f).J
} Q&rpW:^v
} `XS6t)!ik
if(breakWhile) UJ<eF/KSmG
break; ~Qeyh^wo
kTt;3Ia
~bhesWk8!
//count++; }>>lgW>n,;
//if(count>4) 22)2olU
// siteStop(); q0,Diouq
} *^ g7kCe(
T]Pp\6ff
ORD@+ {
System.err.println("文件下载结束！"); 5v<BB`XWp
} _0<qS{RW
catch(Exception e){e.printStackTrace ();} XOAZ
} 0ZlF#PJA
]^uO3!+
LSS3(l[,:
//获得文件长度 TU&gj1
public long getFileSize() 17 Hdj
{ O|}97a^
int nFileLength = -1; 8xW_N"P.>
try{ Tl6%z9rY@
URL url = new URL(siteInfoBean.getSSiteURL()); :$lx]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )<nr;n
httpConnection.setRequestProperty("User-Agent","NetFox"); !c(B c^
89?$xm_m
*+{umfZy
int responseCode=httpConnection.getResponseCode(); aOFF"(]Cl
if(responseCode>=400) ^&>(_I\w.6
{ "9:1>Gr{G
processErrorCode(responseCode); F 0q#.
return -2; //-2 represent access is error +q[puFfl
} a=>PGriL
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,Y6Me+5B
String sHeader; sg RY`U.C
ZnVi.s~1V
pj4M|'F7
for(int i=1;;i++) 5B)Z@-x2
{ I@76ABu^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?aR)dQ
//Utility.log(in.readLine()); 96x0'IsaG
sHeader=httpConnection.getHeaderFieldKey(i); apPn>\O
if(sHeader!=null) [Dni>2@0
{ u2,V34b-
if(sHeader.equals("Content-Length")) Y5M>&}N
{ }%Dsy2:y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); BuII|j
break; 1A^~gYr
} |}P4Gr}6
} `'H"|WsT
else $$_aHkI j
break; K6d9[;F
} ?]+{2&&$
} v0&E!4q*'
catch(IOException e){e.printStackTrace ();} O:3LA-vA
catch(Exception e){e.printStackTrace ();} ~OO&%\$k
[R:\
{L^b['h@
Utility.log(nFileLength); K"B2 SsC
\q(DlqTqs
9&a&O Z{
return nFileLength; {fW(e?8)
} PZmg7N
/2Q@M>
Vw0cf;
//保存下载信息（文件指针位置） u?6L.^Op
private void write_nPos() J-yj&2
{ {U/a h2*
try{ 0 UdAF
output = new DataOutputStream(new FileOutputStream(tmpFile)); # Un>g4>Rh
output.writeInt(nStartPos.length); :I*G tq
for(int i=0;i<nStartPos.length;i++) |d =1|C%,
{ o\6A]T=R
// output.writeLong(nPos); f.SV-{O_
output.writeLong(fileSplitterFetch.nStartPos); uH1%diL^
output.writeLong(fileSplitterFetch.nEndPos); f Glvx~
} Gu?OyL
output.close(); 1ga.%M*
} c]3% wL
catch(IOException e){e.printStackTrace ();} Y?G\@6
catch(Exception e){e.printStackTrace ();} $J}d6%
} @y?<Kv}s
2~[f<N
z=C'qF`
//读取保存的下载信息（文件指针位置） (T+fO}0
private void read_nPos() wn2+4> |~p
{ xrb %-vT
try{ -v"\WmcS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F/GfEMSE
int nCount = input.readInt(); /;>U0~K
nStartPos = new long[nCount]; K8xwPoRL
nEndPos = new long[nCount]; G&8)5d[
for(int i=0;i<nStartPos.length;i++) {nTQc2T?;
{ -ZwQL="t
nStartPos = input.readLong(); el GP2x#:
nEndPos = input.readLong(); aBv3vSq>Q
} 5MUM{(C
input.close(); G=?2{c}U
} T4MB~5,i
catch(IOException e){e.printStackTrace ();} &-^|n*=g6
catch(Exception e){e.printStackTrace ();} >b9nc\~
} )9LlM2+y
hwgLJY?
F|.,lb |L
private void processErrorCode(int nErrorCode) GiI|6z!
{ IoUQ~JviA
System.err.println("Error Code : " + nErrorCode); C/AqAW1
} m]LR4V6k|
rz/^_dV
A0Z<1|6r*
//停止文件下载 &+F|v(|r
public void siteStop() +|6 '7Z(9
{ ukM11LD5x
bStop = true; 'wh2787
for(int i=0;i<nStartPos.length;i++) 5m2`$y-nb
fileSplitterFetch.splitterStop(); f%r0K6p
[>+}2-#
pZ4]KxX@
} ' *hy!f]
} P=v 0|Y*q|
//负责部分文件的抓取 %J)n#\
**FileSplitterFetch.java d#~^)r
*/ x0aPY;,N0
package NetFox; 0a<:.}
?1%/G<
`U:W(\L
import java.io.*; N$u;Q(^
import java.net.*; }<?1\k
9nW/pv
9[.vtk\iyH
public class FileSplitterFetch extends Thread { 7+^9"k7
F<SCW+>z2a
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String sURL; //File URL N~I2~f
long nStartPos; //File Snippet Start Position Qn`$xY9mT
long nEndPos; //File Snippet End Position 1O" Mo
int nThreadID; //Thread's ID yL =*yC
boolean bDownOver = false; //Downing is over -"*UICd
boolean bStop = false; //Stop identical :W]IJ mI\
FileAccessI fileAccessI = null; //File Access interface HzADz%~
o5~o Rmsr
#'"zyidu
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [AAG:`
{ :5kgJu
this.sURL = sURL; k&Z3v.
this.nStartPos = nStart; Ec!fx\
this.nEndPos = nEnd; GS),rNBur
nThreadID = id; "r@f&Ssxb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G55-{y9Q
} m(Hb! RT
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FFE IsB"9
public void run() T(UdV]~]"
{ 96W!~w2xx
while(nStartPos < nEndPos && !bStop) xDRNtLj<u
{ f5)4H
cW+6Emh
HEZgHL
try{ Be?b| G!M
URL url = new URL(sURL); {P'TtlEp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tnx)_f
httpConnection.setRequestProperty("User-Agent","NetFox"); u$T`Bn
String sProperty = "bytes="+nStartPos+"-"; 3&*_5<t\X
httpConnection.setRequestProperty("RANGE",sProperty); |Ld/{&Qr
Utility.log(sProperty); [Yt!uhww
?$rSbw
_Ju@<V$
InputStream input = httpConnection.getInputStream(); 2^-Z17Z}
//logResponseHead(httpConnection); \9[_*
hVvPI1[2
H)XHlO^
byte[] b = new byte[1024]; j@OGl&'^-
int nRead; fBgW0o.Bu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^T}6oUd
{ FmU>q)
nStartPos += fileAccessI.write(b,0,nRead); 8u+FWbOl]
//if(nThreadID == 1) B o@B9/ABv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wSrq?U5q
} VlGg?
zj G>=2
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Utility.log("Thread " + nThreadID + " is over!"); dV{N,;z
bDownOver = true; Rg/*)SKj
//nPos = fileAccessI.write (b,0,nRead); o_un=ygU
} T<!&6,N A
catch(Exception e){e.printStackTrace ();} yc|j]?
} R-v99e iN
} [/.5{|&GSt
)ESF)aKMiz
oBVYgv)
//打印回应的头信息 &?.k-:iN
public void logResponseHead(HttpURLConnection con) \Qp #utC0s
{ GyE-fB4C
for(int i=1;;i++) yHvF"4]
{ @S3G>i
String header=con.getHeaderFieldKey(i); 7_$Xt)Y{
if(header!=null) H^Th]-Zl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;d"F'd
Utility.log(header+" : "+con.getHeaderField(header)); .gPE Qc+D
else O0?.$f9 s
break; &w{""'
} *G{%]\s?
} {fsU(Jj\
IvLo&6swW
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public void splitterStop() 2i+'?.P
{ [qhQj\cK
bStop = true; Aj`zT'
} kj(Ko{
INQ0h`T
EYc, "'
} _c}@Fi+E
R-Y|;
;aA,H&
/* ZVo%ssVt
**FileAccess.java -i``yf?P
*//文件访问(定位，写) "zSi9]j
package NetFox; &Nx'Nq9y
import java.io.*; uus}NZ:*l
E}U[VtaC
Vmj7`w&
public class FileAccessI implements Serializable{ %j],6wW5J
?b?`(JTR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;k6>*wFl|!
RandomAccessFile oSavedFile; B~HA 32
long nPos; r3a$n$Qw
4@6!E^
}kg?A oo
public FileAccessI() throws IOException 2#z6=M~A
{ Y9rW_m@B
this("",0); lWj|7
} LM:|Kydp3
K/;FP'.
-!E))|A
public FileAccessI(String sName,long nPos) throws IOException 74*1|S<
{ }]w/`TF
oSavedFile = new RandomAccessFile(sName,"rw"); r3X|*/
this.nPos = nPos; as\6XW$;Q
oSavedFile.seek(nPos); b2;+a(
} \VL[,z=q.
i~\fpay
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public synchronized int write(byte[] b,int nStart,int nLen) +QNFu){G
{ $~UQKv>
int n = -1; AJ-p|[wPz
try{ +hdD*}qauC
oSavedFile.write(b,nStart,nLen); |*079v
n = nLen; [t55Kz*cD
} sW)C6 #
catch(IOException e) j-2`yR
{ wN,DTmtD
e.printStackTrace (); 4^1B'>I
} *@'4 A :A
XGE:ZVpW
%AbA(F
return n; yYmV^7G
} nenYP0
uLV@D r
'Z LGt#
} uG1 1~uAt
+pU\;x
=PXQX(_
/* [KXxn>n
**SiteInfoBean.java w[w{~`([",
*/ #~um F%#
package NetFox; ND[u$N+5x"
|He,v/r
l,}{Y4\G
public class SiteInfoBean { KE\p|Xi
t ZUZNKODW
D$g|f[l
private String sSiteURL; //Site's URL $M\|zUQu.
private String sFilePath; //Saved File's Path j""I,$t
private String sFileName; //Saved File's Name )5Yv7x(K
private int nSplitter; //Count of Splited Downloading File M0`nr}g
$3BCA)5:
R }M'D15
public SiteInfoBean() =jvM$
{//nSplitter的缺省值为5 /sY(/ JE
//default value of nSplitter is 5 =T5vu~[J/e
this("","","",5); LO@.aJpp
} %Kd&A*
,]@K6
.$b]rx7$~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e*_8B2da
{ %+oWW5q7
sSiteURL= sURL; dsP|j(y
sFilePath = sPath; |K?fVL
sFileName = sName; `j*&F8}
this.nSplitter = nSpiltter; QjETu
iMRb` \KH
K1>.%m
} %]%.{W\j3
\&\_[y8U
BQVpp,]
public String getSSiteURL() Mw!?2G[|
{ <apsG7(7
return sSiteURL; fLK*rK^{"
} vQ=W<>1
\a+F/I$hwa
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public void setSSiteURL(String value) 7"F w8;k
{ .{D[!Dp#h
sSiteURL = value; dDN#>|
} +7?p&-r)x
2<}^m/}
q[{q3-W
public String getSFilePath() /km^IH
{ s~Wjh7'
return sFilePath; ,>CFw-Nxu
} 9 O| "Ws>{
0'O;H[nrl
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public void setSFilePath(String value) v'*
{ "!<Kmh5
sFilePath = value; 6'W79
} ~rEU83
:P`sK&b_
RC Fb&,51
public String getSFileName() GL&ri!,
{ f9H;e(D9]
return sFileName; "m +Eu|{
} &n|! '/H
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E :*!an
public void setSFileName(String value) `+$'bNPn&
{ LNml["
sFileName = value; I1U{t
} =zXpeo&|m
S!8eY `C.
~Kda#=
public int getNSplitter() '5wa"/ ?w
{ uRG0}>]|U
return nSplitter; [P)'LY6F
} =-jkp
(V@g?|LZ
&'V_80vA
public void setNSplitter(int nCount) x|*v(,7b]!
{ x{<WJ|'B
nSplitter = nCount; $7gzu4f
} I z~#G6]M
} !zLd,`
CF9a~^+%
]]@jvU_?kS
/* Fh& `v0
**Utility.java `g6XVa*%#
*/ ;k^wn)JE$
package NetFox; wl^bvHG
4XK*sR0-`
Cl[ '6Lk
public class Utility { o!L1Qrh
`;WiTE)&)
Z `O.JE
public Utility() :gDIGBK,
{ 0trVmWQ8
w=d#y )1
Da1BxbDeI
} =[(1u|H9
X;flA*6V
//线程睡眠 /pgfa-<
public static void sleep(int nSecond) GdEkA
{ <ro0}%-z>M
try{ qc~6F'?R
Thread.sleep(nSecond); 3v;o`Em&
} ??12 J#
catch(Exception e) ~\4l*$3(^
{ )v;>6(
e.printStackTrace (); ('Wo#3b$
} w_pEup\`
} 4>>{}c!nf
'|&}rLr:+
//日志 w{)*'8oCB
public static void log(String sMsg) f!ehq\K1k
{ 3 8pw
System.err.println(sMsg); m9Gyjr'L
} soW.
7&XU]I
%!%3jo0t
public static void log(int sMsg) +oBf\!{cW
{ meu\jg
System.err.println(sMsg); "RuJlp
} i;lzFu)G
} |vz<FR6
_IOeO
&+6XdhX
/* QKc3Q5)@j
**TestMethod.java 6=A2Y:8
*/ }M?GqA=
package NetFox; sY7:Lzs.,
D/:~#)
Z!G_" 3
public class TestMethod { rJ ?Y~Q
mm/U9hbp%
I?dh"*Js&
public TestMethod() -VD[iH
{ ///xx/weblogic60b2_win.exe 8Fx~i#FT
try{ FMhwk"4L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6:>4}WOP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T[U&Y`3g
SiteFileFetch fileFetch = new SiteFileFetch(bean); N~l(ng9'U
fileFetch.start(); Smo^/K`f9
} [%;LZZgl
catch(Exception e){e.printStackTrace ();} ?VEJk,/k
iI+kZI-
$5yS`IqS
} dG.s8r*?M
3ag*dBbs
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public static void main(String[] args) 78#je=MDg
{ Gv>,Ad ka
new TestMethod(); Sd' uXX@
} _7~O>.
} :-.R*W
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