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)); Y8xnvK*
} r{3`zqo
for(int i=0;i<nEndPos.length-1;i++) Xv(9 YhS
{ X!+ a;wr
nEndPos = nStartPos[i+1]; ,$(v#Tz
} v/6,eIz
nEndPos[nEndPos.length-1] = nFileLength; CoN/L`.SN
} z7}zf@Y-qv
} >Ezwl5b
Rm1`D
CO+jB
//启动子线程 .7^-*HT}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1X}Tp\e
for(int i=0;i<nStartPos.length;i++) a9_KQ=&CI
{ 8 =Lv7G%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 40sLZa)e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P+|8MT0
nStartPos,nEndPos,i); J7] 60H#P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #.t{g8W\C
fileSplitterFetch.start(); !>);}J!e]
} *U^hwL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *M<=K.*\G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]<?)(xz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1KR|i"
nEndPos = " + nFileLength); &>b1ES.>
// fileSplitterFetch[nPos.length-1].start(); ;l4\^E1
{!?RG\EYN
pNWp3+a'
//等待子线程结束 >^ar$T;Ys
//int count = 0; R}26"+~
//是否结束while循环 qiryC7.E
boolean breakWhile = false; 0-~x[\>>
[$Bb'],k
ll09j Ef
while(!bStop) (`Mz.VN
{ y5D?Bg|M
write_nPos(); +E[)@;T
Utility.sleep(500); w[G_w:$a
breakWhile = true; Z69IHA[
bbkI}d%(Ng
>U/g*[>
for(int i=0;i<nStartPos.length;i++) fb;"J+
{ |;-r};
if(!fileSplitterFetch.bDownOver) L2$L.@
{ sYP@>tHC
breakWhile = false; MW>28
break; j]D =\
} !Qzp!k9d
} /j@r~mt/pA
if(breakWhile) O;sQPG,v
break; [k}\{i>
}]?G"f t K
gQDK?aQX
//count++; i?=.; 0[|
//if(count>4) o+Z9h1z%,
// siteStop(); iRtDZoiD'
} S:\hcW6
Y\|J1I,Z4
l!` 0I] }
System.err.println("文件下载结束！"); * XGBym
} e!Okc*,
catch(Exception e){e.printStackTrace ();} W-QPO
} X5<.%@Z
93DBZqN
B'/ >Ax&
//获得文件长度 0.0!5D[
public long getFileSize() 1hS~!r'qqv
{ x@}Fn:c!5
int nFileLength = -1; ,O!aRvzap
try{ Z$XpoDbOy
URL url = new URL(siteInfoBean.getSSiteURL()); LS$82UB&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L:Eb(z/D
httpConnection.setRequestProperty("User-Agent","NetFox"); PtOnj)Q
KHN ,SB
}O
int responseCode=httpConnection.getResponseCode(); l$9,
if(responseCode>=400) 74(J7
{ 1iDo$]TEK
processErrorCode(responseCode); =7,UqMl_
return -2; //-2 represent access is error "6QMa,)D
} d]`,}vi#E9
J,Ap9HJt
;P~S/j[ 8
String sHeader; Q>ytO'v1
.Tv(1HAc2l
$'*BS
for(int i=1;;i++) r ngw6?`n-
{ V5r7eC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L{pg?#\yC
//Utility.log(in.readLine()); oy: MM
sHeader=httpConnection.getHeaderFieldKey(i); 2&URIQg*J
if(sHeader!=null) #{,IY03
{ 18`%WUPnT
if(sHeader.equals("Content-Length")) E%B Gf}h
{ SqB|(~S
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D0i30p`
break; +Bfi/>
} N@)~j+Pz
} 2N 4>
else :5J6rj;_
break; 3kY4V*9@-
} Bdepvc}[#
} ZRfa!9vl
catch(IOException e){e.printStackTrace ();} s3 $Q_8H
catch(Exception e){e.printStackTrace ();} 3)SZVME1Z
Q$j48,e
;$< ek(i7
Utility.log(nFileLength); }wXD%X@)l
t7FQ.E,T
&J:)*EjVl5
return nFileLength; nDy=ZsK
} koZp~W-
p04+"
"cM5=;
//保存下载信息（文件指针位置） G- WJlu
private void write_nPos() I_7EfAqg(
{ It-*CD9
try{ He3zV\X[Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2z3A"HrlA
output.writeInt(nStartPos.length); P.DWC'IBN
for(int i=0;i<nStartPos.length;i++) ?F{xDfqw
{ 'O9=*L)X
// output.writeLong(nPos); @x +#ZD(
output.writeLong(fileSplitterFetch.nStartPos); / u6$M/Cf>
output.writeLong(fileSplitterFetch.nEndPos); <Q)}
} B$EP'5@b
output.close(); \'*`te:{
} ,c l<74d
catch(IOException e){e.printStackTrace ();} [{$0E=&0
catch(Exception e){e.printStackTrace ();} i]pG}SJ
} "~ stZ.
@un }&URp
2"mj=}y6
//读取保存的下载信息（文件指针位置） 8 GN{*Hg
private void read_nPos() F9r*ZyNlx
{ o#/iR]3
try{ 1H7Q[ 2E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )W|jt/
int nCount = input.readInt(); p>3'77 V
nStartPos = new long[nCount]; n4y6Ua9m{
nEndPos = new long[nCount]; %;$Y|RbmqE
for(int i=0;i<nStartPos.length;i++) _B FX5ifK
{ 38i,\@p`9$
nStartPos = input.readLong(); 3 ?~+5DU
nEndPos = input.readLong(); 8-YrmP2k
} WEAXqDjM
input.close(); +Ob#3PRy
} );H[lKy
catch(IOException e){e.printStackTrace ();} 4+,Z'J%\[7
catch(Exception e){e.printStackTrace ();} T]-~?;Jh8
} [)vwg`]
*PU,Rc()6
w[YbL2p
private void processErrorCode(int nErrorCode) ygt)7f5
{ >]8.xkQq
System.err.println("Error Code : " + nErrorCode); 4LJ}>e
} X{9o8 *V
/j@ `aG(a
!5t 3Y
//停止文件下载 4{t$M}?N
public void siteStop() 2tm-:CPG
{ ~la04wR28
bStop = true; >Fk`h=Wd
for(int i=0;i<nStartPos.length;i++) T?{9Z
fileSplitterFetch.splitterStop(); v=-3 ,C
Qp&ySU8
h xJgxM
} :=v{inN
} #q.G_-H4J@
//负责部分文件的抓取 6*33k'=;F
**FileSplitterFetch.java _O9H._E
*/ Y_hRL&u3W
package NetFox; ld:alEo
~ O=|v/]
)^f Q@C8
import java.io.*; R9G)X]
import java.net.*; 9yw/-nA
pu*u[n
WVK-dBU
public class FileSplitterFetch extends Thread { l{m~d!w`a
MPy][^s!
E9 q;>)}
String sURL; //File URL D#}Yx]Q1
long nStartPos; //File Snippet Start Position B/kn&^z$|~
long nEndPos; //File Snippet End Position K(fLqXE%
int nThreadID; //Thread's ID g_c)Ts(
boolean bDownOver = false; //Downing is over bv>lm56
boolean bStop = false; //Stop identical jZ,[{Z(N
FileAccessI fileAccessI = null; //File Access interface a;(zH*/XK
JMlhBh
\[I .
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $=xQX
{ ~<OjXuYu
this.sURL = sURL; >1I2R/'
this.nStartPos = nStart; (ul-J4E\O
this.nEndPos = nEnd; %kFELtx
nThreadID = id; 1y-lZ}s_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 CVG>[~}(9'
} EFt`<qwj
<`UG#6z8
C_ZD<UPA\
public void run() H-KwkH`L4
{ _D,f4.R
while(nStartPos < nEndPos && !bStop) ,T*_mDVY
{ VD3MJ8!w
%7d@+ .
*u;">H*BW
try{ 1za'u_
URL url = new URL(sURL); ,xD*^>!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x$J.SbW
httpConnection.setRequestProperty("User-Agent","NetFox"); jNG?2/P6&
String sProperty = "bytes="+nStartPos+"-"; 1(7.V-(G
httpConnection.setRequestProperty("RANGE",sProperty); 'qF3,Rw
Utility.log(sProperty); TKu68/\)
BRXb<M^;_
KSB_%OI1
InputStream input = httpConnection.getInputStream(); Yj7= T%5
//logResponseHead(httpConnection); 6aZt4Lw2\
yki51rOI*
3_*Xk. .d
byte[] b = new byte[1024]; Etc?;Z[F#
int nRead; %i -X@.P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^lc}FN
{ :`u&TXsu
nStartPos += fileAccessI.write(b,0,nRead); K[>@'P}y
//if(nThreadID == 1) UtBlP+bE?y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i,Wm{+H-O
} /\a]S:V-j
OV("mNh
p@7i=hyt`p
Utility.log("Thread " + nThreadID + " is over!"); H;*a:tbxO+
bDownOver = true; x1V2|~;p|
//nPos = fileAccessI.write (b,0,nRead); oD#<?h)(
} ^c0$pqZ}r
catch(Exception e){e.printStackTrace ();} P`3s\8[Q
} 7l#2,d4
} "^ 6lvZP(
[bi3%yWh
?%xhe
//打印回应的头信息 m,gy9$
public void logResponseHead(HttpURLConnection con) _{c|o{2sj
{ yw*mA1v
for(int i=1;;i++) cR=94i=t
{ kBiBXRt
String header=con.getHeaderFieldKey(i); h/X5w4
if(header!=null) ( ztim
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >)n4sMq
Utility.log(header+" : "+con.getHeaderField(header)); U%^eIXV|
else ~6-"i0k
break; % L >#
} 1] %W\RHxo
} b$goF }b'g
;naq-%'Sg
W%>i$:Qq
public void splitterStop() KZrMf77=
{ AvrL9D
bStop = true; KM/U?`6>:
} p2Dh3)&
:>P4L,Da]
H}sS4[z
} a/QtJwIV
*^@#X-NG
crJ7pe9
/* ~[|V3h4v
**FileAccess.java ePq13!FC/
*//文件访问(定位，写) JO2ZS6k[
package NetFox; ^"O{o8l>2
import java.io.*; +}7Ea:K
j{{~ZM
yV:EK{E
public class FileAccessI implements Serializable{ 0%xR<<gir
*L%6qxl`V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *xE"8pN/
RandomAccessFile oSavedFile; \7Gg2;TA6o
long nPos; {W5ydHXy
>=-GD2WK
=tr1*s{
public FileAccessI() throws IOException ~L%Pz0Gg
{ NP K#].F
this("",0); +}_Pf{MW
} 1Pk mg%+
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_0'm4?"
public FileAccessI(String sName,long nPos) throws IOException {$EH@$./
{ =n@F$/h
oSavedFile = new RandomAccessFile(sName,"rw"); 1.# |QX
this.nPos = nPos; C#MFpT
oSavedFile.seek(nPos); #yW.o'S+
} [YC=d1F5
_W)`cr
;i<$7MR.e
public synchronized int write(byte[] b,int nStart,int nLen) W8w3~
{ bTZ>@~$
int n = -1; $.H:8^W
try{ 3gb|x?
oSavedFile.write(b,nStart,nLen); ?h/xAl
n = nLen; CF]i}xpWV
} >qR7'QwP
catch(IOException e) 7#QLtU
{ 7OB%A&
e.printStackTrace (); y Wpi|
} 41u*w2j
kmryu=
Lp_$?MCD.
return n; #@9)h
} z5x _fAT(
*yJ[zXXjJ
led))qd@V-
} &~RR&MdZ2
K&*iw`
LH4>@YPGE#
/* K*~]fy
**SiteInfoBean.java ?a S%
*/ m9Ax\lf
package NetFox; CdY8#+"
]<1HM"D
oizT-8i@N
public class SiteInfoBean { c! @F
U#bl=%bF
#O"
private String sSiteURL; //Site's URL wuA^'T
private String sFilePath; //Saved File's Path $[g_=Z
private String sFileName; //Saved File's Name O`WIkBV!
private int nSplitter; //Count of Splited Downloading File >&OUGu|
#/|75 4]]
zrs<#8!Y_!
public SiteInfoBean() ?>af'o:
{//nSplitter的缺省值为5 2R]&v;A
//default value of nSplitter is 5 -D^L}b
this("","","",5); EFAGP${F
} =+Im*mgNn
EeB ]X24
4e +~.5r@i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1"}cdq.
{ Z?oG*G:
sSiteURL= sURL; TI=h_%mO
sFilePath = sPath; QYQtMb,
sFileName = sName; (zG.aaz*C
this.nSplitter = nSpiltter; .-0%6] cFD
$6T3y8
n 6{2]&sd
} MM?`voj~`p
Y>BP?l
m 41t(i
public String getSSiteURL() 'Hw4j:pS
{ nBN&.+3t
return sSiteURL; JQ@fuo %
} Gih[i\%Q
_tAQ=eBO
&-%X:~|:X
public void setSSiteURL(String value) P}V=*g
{ k;I &.H
sSiteURL = value; EATu KLP\
} 3$VxRz)
N L'R\R
HRB[GP+
public String getSFilePath() fTqC:r|st
{ o%[U
return sFilePath; fj>C@p
} fQ+\;iAU
aE|OTm+@9;
[Il~K
public void setSFilePath(String value) u3J?bR
{ T@[!A);
sFilePath = value; f?56=& pHY
} K=?VDN
RKZ6}q1n
C5W>W4EM
public String getSFileName() b.F^vv"]]
{ :?Y$bX}a
return sFileName; 5\Fz!
} {_#yz\j
hXn3,3f3oZ
YE}s
public void setSFileName(String value) 4=Gph
{ eKN$jlg
sFileName = value; Bfr'Zdw
} iWLa>z|,
nmFC%p)4
npp[@*~
public int getNSplitter() 9bJQT'<R
{ '9?;"=6(
return nSplitter; EE=3
} ZH,4oF
w$|l{VI
bU54-3Ox*
public void setNSplitter(int nCount) hWo=;#B*
{ ]3Dl)[R
nSplitter = nCount; ZJ,cQ+fn
} Thr*^0$C
} {g6Qv-
;AJTytE>%
*[+)7
/* %Sk@GNI_
**Utility.java v4Ga0]VN$8
*/ <#+44>h
package NetFox; &<pKx!
($nrqAv4
~8T(>!hE1h
public class Utility { ,8MLoZ_
BZv+H=b
v"^~&q0x
public Utility() w}R~C
{ $gpG%Qj
fyWO
*&Lq!rFS
} P u0uKE
LjB;;&VCn
//线程睡眠 8Q{9>^
public static void sleep(int nSecond) l8h&|RY[
{ o>/O++7Ra
try{ c`*TPqw(B[
Thread.sleep(nSecond); {yA$V0`N{
} Q&'}BeUbm
catch(Exception e) VOTv?Vf
{ 7OCwG~_^
e.printStackTrace (); ;Xvp6.:
} _c$9eAe
} '1^B+m
X^9d/}uTa
//日志 fq[;%cr4
public static void log(String sMsg) X|D!VX>#!
{ l`-bFmpA
System.err.println(sMsg); u{N,Ib 8
} ;6ecrQMw&
4)>FS'=
KInk^`C/H
public static void log(int sMsg) y! .J
{ Zk8|K'oHx
System.err.println(sMsg); 6]zd.W
} =qy=-j]
} 4_v]O
YwY74w:
[+m?G4[
/* vIl+#9L0
**TestMethod.java so$(_W3E,
*/ S& #U!#@
package NetFox; ((tv2
z7M_1%DEx
.\0isO
public class TestMethod { W|:lVAP.|}
%ek'~
Eodn/
public TestMethod() sVk$x:k1M
{ ///xx/weblogic60b2_win.exe 54-#QIx|
try{ \#-W <
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :0)3K7Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OA/WtQ5
SiteFileFetch fileFetch = new SiteFileFetch(bean); |tR OL9b
fileFetch.start(); v:Tzv^
} U7uKRv9
catch(Exception e){e.printStackTrace ();} vx_o(wof
+YLejjQ
zA+~7;7E
} /&F,V+x
W>VP'vn}
:1XtvH
public static void main(String[] args) :l7U>~ o
{ I1oje0$
new TestMethod(); #_Z$2L"U
} ?m$a6'2-,J
} Uj+j}C
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