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)); %[0V>
} |SC^H56+
for(int i=0;i<nEndPos.length-1;i++) VE5w!of
{ KCd}N
nEndPos = nStartPos[i+1]; %cMX]U
} rlr)n\R#
nEndPos[nEndPos.length-1] = nFileLength; :&ir5xHS
} <4SY'-w
} IMLk{y%6
O\;Z4qn2=
d;O16xcM/
//启动子线程 GlYNC&,VL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -C]RFlV
for(int i=0;i<nStartPos.length;i++) y?j#;n0
{ a5jc8S>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ei)ljvvmHP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D+?/MrP
nStartPos,nEndPos,i); 4eTfb
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s>(OK.o
fileSplitterFetch.start(); }eh<F^
} 7K3S\oPej
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -b+VzVJZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Cmg(#$X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q!8AFLff4
nEndPos = " + nFileLength); \}Fx''
// fileSplitterFetch[nPos.length-1].start(); r'xZF~}k"~
QPf*!E
xo2PxUO
//等待子线程结束 heJI5t,
//int count = 0; nN1\
//是否结束while循环 Yy`\??,
boolean breakWhile = false; gV@FT|j!i
- &u]B$
! iuDmL
while(!bStop) h`n,:Y^++P
{ >+y[HTf-
write_nPos(); rZ`ob x\S
Utility.sleep(500); 9r.Os
breakWhile = true; *TQXE:vZ[
umZy=KHj
ZGgKCCt
for(int i=0;i<nStartPos.length;i++) Rd~-.&
{ 9/3gF)I}
if(!fileSplitterFetch.bDownOver) xtWQ.
{ &}:'YK*X
breakWhile = false; \'Oi0qo>
break; ZHT_o\
} m "'
} /H.w0fu&.S
if(breakWhile) 94 58.!3
break; !h3$C\
d-Vttxa6
AsJN~<0h
//count++; I3`WY-uv
//if(count>4) 5%,5Xe4p
// siteStop(); 3V~871:-~
} .4E5{F{~
^R- -&{I
6'CZfs\
System.err.println("文件下载结束！"); 2F9Gx;}t5=
} ~+w'b7T,=
catch(Exception e){e.printStackTrace ();} kt?G\H!}
} y%%D="
{FRUB(68b
,aOi:aaZRT
//获得文件长度 ^o&3+s}M
public long getFileSize() GJ"S*30
{ q6DuLFatc*
int nFileLength = -1; \]RPxM:_>
try{ Q@]~O-
URL url = new URL(siteInfoBean.getSSiteURL()); _8x:%$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u#(VR]u\7
httpConnection.setRequestProperty("User-Agent","NetFox"); {Q9?Q?
'J\nvNm
Fy:CG6@X
int responseCode=httpConnection.getResponseCode(); |a9d]^
if(responseCode>=400) QOXG:?v\
{ q?} /q
processErrorCode(responseCode); >g7}JI&
return -2; //-2 represent access is error cmG*"
} ]}7FTMGbY
y4sKe:@2
|@'/F#T
String sHeader; I/YBL
8@;|x2=y
ptJ58U$Bb
for(int i=1;;i++) sa8JN.B
{ +tOmKY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j9Qd 45
//Utility.log(in.readLine()); `pr$l
sHeader=httpConnection.getHeaderFieldKey(i); 7#/->Y
if(sHeader!=null) a#3+PB#
{ Ws;S=|9,7~
if(sHeader.equals("Content-Length")) ='r86vq
{ Ff6l"A5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "&h{+DHS
break; co!o+jP
} s<3cvF<
} Hq<Sg4nz
else 2J?ON|2M
break; 9*s''=
} u|]{|Ya'%
} FuqMT`
catch(IOException e){e.printStackTrace ();} {qxFRi#\k
catch(Exception e){e.printStackTrace ();} ."`mh&+`
>]b>gc?3
&CP0T:h
Utility.log(nFileLength); 2@7f^be
O7<--
vG E;PwR
return nFileLength; r 0mA
} ?\Fo|__
yFt$L'#
)?_x$GKY
//保存下载信息（文件指针位置） `D *U@iJ
private void write_nPos() _8zZ.~)
{ T}fH
try{ [l~Gwaul>
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;MSdTHN"
output.writeInt(nStartPos.length); 72Zp%a=
for(int i=0;i<nStartPos.length;i++) ~>2DA$Ec
{ ? 2#tIND
// output.writeLong(nPos); X8(H#Ef[
output.writeLong(fileSplitterFetch.nStartPos); aTi2=HL=S
output.writeLong(fileSplitterFetch.nEndPos); kdmmfw
} :Q\Es:y
output.close(); YoC{ t&rY
} Cn\5Vyrl
catch(IOException e){e.printStackTrace ();} h>0R!Rl8
catch(Exception e){e.printStackTrace ();} r0MUv}p#|L
} :vsBobiJ
|:qaF
Tt^PiaS!
//读取保存的下载信息（文件指针位置） /NE<?t N
private void read_nPos() gc5u@(P"
{ ;Gf,I1d}{
try{ <V`1?9c7D1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sY|by\-c
int nCount = input.readInt(); aC!e#(q
nStartPos = new long[nCount]; BH`%3Mw
nEndPos = new long[nCount]; 4k$i:st;
for(int i=0;i<nStartPos.length;i++) ;dC>$_P?
{ rN$U%\.I
nStartPos = input.readLong(); <[*%d~92z
nEndPos = input.readLong(); <n#phU Q
} ;JpsRf!
input.close(); >JSk/]"
} NY(z3G
catch(IOException e){e.printStackTrace ();} 5Q/&,NP
catch(Exception e){e.printStackTrace ();} !UzMuGj
} 8%+F.r
3bWYRW
B|fh 4FNy
private void processErrorCode(int nErrorCode) v d{`*|x
{ ;FQ<4PR$
System.err.println("Error Code : " + nErrorCode); k4HE'WY
} S*aMUV&
W't?aj I|
K^zu{`S
//停止文件下载 i>*|k]
public void siteStop() wSV}{9}wr%
{ b-/8R|Mem
bStop = true; |qOoL*z
for(int i=0;i<nStartPos.length;i++) E*B6k!:
fileSplitterFetch.splitterStop(); y3Z\ Y[
-(oFO'Lbg
6np
} rT#2'-f
} )2pOCAjL2
//负责部分文件的抓取 k vuSE
**FileSplitterFetch.java pqT+lai)#
*/ ]3KMFV}
package NetFox; hRU5CH/!
v47S9Vm+
V(6*wQ`&
import java.io.*; sxK|0i}6
import java.net.*; tyI!y~-z
$`a>y jma
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public class FileSplitterFetch extends Thread { Rfx}[!<{N
c>$PLO^
uc~/l4~N
String sURL; //File URL {0(:5%
long nStartPos; //File Snippet Start Position av8\?xmo.$
long nEndPos; //File Snippet End Position ^ ,cwm:B@
int nThreadID; //Thread's ID RV=Z$
boolean bDownOver = false; //Downing is over .="/n8B
boolean bStop = false; //Stop identical nt:d,H<p
FileAccessI fileAccessI = null; //File Access interface w;OvZo|
n5NwiSE
sC}p_'L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 78MQoG<
{ v1j&oA}$.
this.sURL = sURL; pzcl@
this.nStartPos = nStart; kq4ii`zi8
this.nEndPos = nEnd; 8mc0(Z@
nThreadID = id; id?B<OM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h>a/3a$g
} ~+)sL1lx
+ g*s%^(E
<Pnz$nH:e
public void run() pYBY"r
{ <E&8g[x6
while(nStartPos < nEndPos && !bStop) $sxm MP
{ [Yyb)Qf
L|`(u
x & ZW f?
try{ v<AFcY
URL url = new URL(sURL); h>:eu#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3UNmUDl[~
httpConnection.setRequestProperty("User-Agent","NetFox"); >qL-a*w:a
String sProperty = "bytes="+nStartPos+"-"; f\vy5''
httpConnection.setRequestProperty("RANGE",sProperty); /\wm/Yx?S
Utility.log(sProperty); 2mt S\bAF
{/2 _"H3:
|=rb#z&
InputStream input = httpConnection.getInputStream(); 3;'RF#VL
//logResponseHead(httpConnection); DGJt$o=&@
|Bhj L,
GF/!@N
byte[] b = new byte[1024]; C[JGt9{Y
int nRead; }~O`(mnD}K
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \2^_v' >K
{ L#~z#
nStartPos += fileAccessI.write(b,0,nRead); w|G4c^KH
//if(nThreadID == 1) 0Q{^BgW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oD8X]R, H
} .kqH}{hf
"Nh}_jO
7Ap==J{a
Utility.log("Thread " + nThreadID + " is over!"); >"|"Gy (
bDownOver = true; ^fqco9^;
//nPos = fileAccessI.write (b,0,nRead); y{#9&ct&
} \\(3gB.Gd
catch(Exception e){e.printStackTrace ();} L3J .Oh
} _0Z8V[
} [9H986=
d8Sr,t+
y3Q2d7G
//打印回应的头信息 n1Fp$9%
public void logResponseHead(HttpURLConnection con) mhi^zHpa
{ qZB}}pM#
for(int i=1;;i++) grZ?F~P8
{ Ch0t'
String header=con.getHeaderFieldKey(i); gCP f1z
if(header!=null) g&?RQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "V>p
Utility.log(header+" : "+con.getHeaderField(header)); J5#shs[M:
else 7f_tH_(
break; Z` zyEP A
} 2 e9lk$
} ,@Aeo9}
egn9O
iZ;y(
public void splitterStop() m[$pj~<\
{ %<yH6h*u
bStop = true; }HLV'^"k
} )Q5ja}-{V
|HfN<4NL
eZvG
} zcCGREe=
oeA}b-Ct0
Jf3xK"in
/* <c_'(
**FileAccess.java SUaXm#9
*//文件访问(定位，写) A[8vD</}_
package NetFox; c0.? d]
import java.io.*; !McRtxq?~
`Qxdb1>mjY
cqZuG}VR
public class FileAccessI implements Serializable{ <E1ngG
z$b'y;k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )Q)H!yin
RandomAccessFile oSavedFile; bSm*/Q
long nPos; Cp!Qd e
4&}dA^F
ZB'ms[
public FileAccessI() throws IOException S*Hv2sl
{ KlSg0s
this("",0); )2g-{cYv
} R$M>[Kjn
th]pqhl>
-,pw[R
public FileAccessI(String sName,long nPos) throws IOException !+{$dB>a
{ hNUkaP
oSavedFile = new RandomAccessFile(sName,"rw"); 0oNy
this.nPos = nPos; bVW2Tjc:
oSavedFile.seek(nPos); 6$x9@x8
} 5$<Ozkj(
g?>V4WF
T@gm0igW/;
public synchronized int write(byte[] b,int nStart,int nLen) Q)%a2s;
{ |N+uEiJ
int n = -1; c?7Wjy
try{ OqlP_^Zz7p
oSavedFile.write(b,nStart,nLen); BQF7S<O+
n = nLen; "iPX>{'En
} r~Vb*~U"
catch(IOException e) bX'.hHR
{ 6[S-%|f
e.printStackTrace (); |L%d^m
} mj|TWDcj+
<}n"gk1is
\\v1\
return n; vQsI^p
} Gid6,J
WOR H4h9
wpV)y Q^
} vi~NfD@s
~F^7L5d}C
BaXf=RsZ
/* =P7!6V\f
**SiteInfoBean.java [;,Xp/
*/ gkMyo`
package NetFox; /4%ycr6
bd[%=5
iVAAGZ>am
public class SiteInfoBean { H?$gHZPI
(GB*+@
:7 OhplI
private String sSiteURL; //Site's URL dvPlKLp
private String sFilePath; //Saved File's Path ||o :A
private String sFileName; //Saved File's Name D{G~7P\.
private int nSplitter; //Count of Splited Downloading File zA%$l&QN]
"fZWAGDBO\
`R@b`3*%v
public SiteInfoBean() o8!uvl}:9
{//nSplitter的缺省值为5 WwAvR5jq
//default value of nSplitter is 5 ^rssZQKY[
this("","","",5); ,!Q^"aOT:
} j@C*kj;-
]mdO3P
?CO..l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D'Y=}I)8Dn
{ xG~7kj3
sSiteURL= sURL; :WHbwu,L$
sFilePath = sPath; 1vUW$)?X
sFileName = sName; =+"=|cQ
this.nSplitter = nSpiltter; K3-Cuku
8XhGo2zf
y_}jf,b4
} <MzXTy3\
oa2v/P1`
Pt[ b;}
public String getSSiteURL() L6n<h
{ 5rlZ'>I.
return sSiteURL; s8|Fe_
} @8"cT-
(c|Ry[$|
=L9;8THY
public void setSSiteURL(String value) Wj"GS!5
{ ObEp0-^?
sSiteURL = value; WR5W0!'Tf
} }/g1s71
y vo4 .u
Xot2L{EIUE
public String getSFilePath() +~f5dJyk`
{ 1YJ@9*l
return sFilePath; q~G@S2=}0}
} 1rGi"kdf
%IHra6
3U&rK)F
public void setSFilePath(String value) Bl*.N9*
{ ZP;WXB`
sFilePath = value; t^SND{[WcM
} gQ=l\/H
`~+[pY1r
]5sU =\
public String getSFileName() ]o2 Z14
{ W $EAo+V
return sFileName; yR4++yk
} _a-At
n2;Vrs,<1&
B(qwTz 51
public void setSFileName(String value) NK$BF(HBi
{ =At)?A9[
sFileName = value; "HrZv+{
} .qD=u1{p9
8rpr10;U
TT3\c,cs
public int getNSplitter() 3&"+)*/ m
{ r(DW,xoK0
return nSplitter; `PI?RU[g*
} f}uW(:f
]Yx&
BfdS3VrZ/
public void setNSplitter(int nCount) Xn*>qm
{ DE!P[$J
nSplitter = nCount; 4M*!'sG\
} =q?sB]n
} )bR`uV9<
1y7FvD~v
jzAXC^FS
/* -@?4Tfl
**Utility.java .BrYz:#A
*/ 23*OuY
package NetFox; NkY7Hg0
B> V)6\
w*krPaT3
public class Utility { N`rz>6,k1
6<{XwmM
7 jiy9[
public Utility() *(CV OY~
{ TpAso[r
bguTWI8bk
CjZIBMGc
} 6![}Jvu>
QM4O|x[
//线程睡眠 @nxpcHj
public static void sleep(int nSecond) )POU58$
{ Uo=_=.GQ
try{ Tjj-8cg
Thread.sleep(nSecond); O 2W2&vY
} rYPj3!#
catch(Exception e) 0+6=ag%
{ @\|Fd)
e.printStackTrace (); Wz)@k2
} 2"8qtG`Et
} iKA}??5e
_<6B.{$\7m
//日志 `=19iAp.
public static void log(String sMsg) zr^"zcfz&
{ <P0&!yN
System.err.println(sMsg); ?eOw8Rom
} Fb<fQIa
DQ9}('^
z(Q 5?+P
public static void log(int sMsg) IA^*?,AZy
{ ]@ N::!m
System.err.println(sMsg); &*9' 0
} M{Hy=:K+
} JV@b(x`
\fJ_,
J>Bc-%.Q
/* *IIuGtS
**TestMethod.java &2,^CG
*/ Hd?#^X
package NetFox; `[F[0fY-
QR{>]I
,| ~Pa
public class TestMethod { :YM1p&|fS
"P8(R
OTD<3Q q
public TestMethod() #y*p7~|@
{ ///xx/weblogic60b2_win.exe 5m9;'SF
try{ _E8doV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KhZ\q|5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YWhp4`m
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'Oa(]Br[
fileFetch.start(); I;+>@Cn(g<
} *s$:"g-
catch(Exception e){e.printStackTrace ();} ?9ScKN
oL -udH
tLzKM+Ct#
} A0 $ds
xew s~74L
i9v|*ZM"
public static void main(String[] args) _l=X?/
{ Uu~~-5
new TestMethod(); A O3MlK9t
} 36\_Y?zx%
} }T&~DVM
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