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)); |D[LU[<C
} 3{TE6&HIa
for(int i=0;i<nEndPos.length-1;i++) zy|h1.gd
{ Z2-"NB
nEndPos = nStartPos[i+1]; aY DM)b}
} =4OV }z=I
nEndPos[nEndPos.length-1] = nFileLength; }C$D-fH8sW
} `3z6y&dmx
} 1bjWWNzQA
Pjq()\/[Z
f=Oj01Ut*
//启动子线程 N9u {)u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4E$d"D5]>p
for(int i=0;i<nStartPos.length;i++) \{qtdTd
{ 9S<V5$}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z@AN0?,`~o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7Jpq7;
nStartPos,nEndPos,i); AE Abny q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V@\u<LO0G
fileSplitterFetch.start(); c<{~j~+
} cs[nFfM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hdqr~9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $8Z4jo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S7@/dHN
nEndPos = " + nFileLength); sWi4+PAM0
// fileSplitterFetch[nPos.length-1].start(); Sae*VvT6
&4*f28 s
<y#@v G
//等待子线程结束 `9A`pC
//int count = 0; J6@RIia
//是否结束while循环 CX; m8
boolean breakWhile = false; H;+98AIy`
6p.y/LMO
5fLp?`T
while(!bStop) 29&F_
{ Bp4#"y2
write_nPos(); ?/(*cA
Utility.sleep(500); *T.V5FB0S
breakWhile = true; 9Fg:
.Y }k@T40a
+6L.a3&(b
for(int i=0;i<nStartPos.length;i++) cs4IO O$
{ }|j#C[
if(!fileSplitterFetch.bDownOver) G{zxP%[E
{ _*xY>?Aq
breakWhile = false; y`cL3 xr4R
break; '}q/;}ih
} Gq7\b({=
} eu//Q'W
if(breakWhile) *g4Uo{
break; .Vs|&c2im
>;}(?+|f
X9rao n
//count++; KXBTJ&
//if(count>4) g3Ul'QJ
// siteStop(); 7_eV.'h
} L:.Rv0XT
{yMkd4v
"S>VqvH3
System.err.println("文件下载结束！"); V=Z%y$1Bc
} iaQFVROu
catch(Exception e){e.printStackTrace ();} Z5`V\$
} QJI]@3 Y
EEvi_Z932
HaF&ooI5+
//获得文件长度 !lp7}[k<y
public long getFileSize() sGa "
{ Vq^b_^
int nFileLength = -1; BU|m{YZ$
try{ /)4Q%Zp
URL url = new URL(siteInfoBean.getSSiteURL()); xX8c>p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @2>ce2+
httpConnection.setRequestProperty("User-Agent","NetFox"); ]#rNz"
1\/~>
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int responseCode=httpConnection.getResponseCode(); x@x5|8:ga
if(responseCode>=400) %Kh}6
{ @}'?o_/C
processErrorCode(responseCode); @k/|%%uP
return -2; //-2 represent access is error I,r0K]
} .fK~IKA
"po;[ Ia2
c#@L~<
String sHeader; \t? ;p-+ta
r/QI-Cf&
I}awembw g
for(int i=1;;i++) u5`b")a
{ T ^/\Rr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qr~zTBT] E
//Utility.log(in.readLine()); P75@Yu(
sHeader=httpConnection.getHeaderFieldKey(i); *~.'lE%[U
if(sHeader!=null) ~x J#NC+
{ Xod/GYG
if(sHeader.equals("Content-Length")) Q{ {=
{ ,<TJh[TzC6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #.LI`nYA
break; n+s=u$%qn
} Tq8U5#NF
} g$z6*bL
else =n;LP#(h?
break; G%CS1#
} +5%ncSJx
} V! .I>
catch(IOException e){e.printStackTrace ();} H<qz rO
catch(Exception e){e.printStackTrace ();} tNAmA
>B.KI}dE
dSS Ai |}
Utility.log(nFileLength); nr&9\lG]G
|WgFLF~k
a24(9(yh
return nFileLength; +;q`A1
} =$_kkVQ$
p;mV?B?oAQ
`*B6T7p1
//保存下载信息（文件指针位置） ^Jc|d,u;s
private void write_nPos() 1=^|
{ ayN[y
try{ LVy (O9g
output = new DataOutputStream(new FileOutputStream(tmpFile)); b>'c
output.writeInt(nStartPos.length); O`;o"\P<
for(int i=0;i<nStartPos.length;i++) Z[kVVE9b?
{ j(c;r>
// output.writeLong(nPos); )t,efg
output.writeLong(fileSplitterFetch.nStartPos); `mquGk|)
output.writeLong(fileSplitterFetch.nEndPos); tHFUV\D;,
} EIOP+9zP
output.close(); C`8.8
} l_ LH!Tu
catch(IOException e){e.printStackTrace ();} ZtpbKy!\$B
catch(Exception e){e.printStackTrace ();} "}0)~,{xB
} !z5Ozm+}
-R`nitf
;20sh^~
//读取保存的下载信息（文件指针位置） JRDIGS_~
private void read_nPos() ^+Vf*YY 8
{ /^`do3a}
try{ LXRIo2ynuw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $Ut1vp1$
int nCount = input.readInt(); DyRU$U
nStartPos = new long[nCount]; e )]
nEndPos = new long[nCount]; =bQ\BY#
for(int i=0;i<nStartPos.length;i++) Bey9P)_Of
{ :=K+~?
nStartPos = input.readLong(); gbu)bqu2x
nEndPos = input.readLong(); z/pxZB~"
} 0 R>!jw
input.close(); jori,"s
} +Ecn
catch(IOException e){e.printStackTrace ();} qh6Q#s>tH
catch(Exception e){e.printStackTrace ();} O/oLQoH
} 161IWos
QL-E4]
[`1@`5SL-
private void processErrorCode(int nErrorCode) w1+ %+x
{ &InFC5A
System.err.println("Error Code : " + nErrorCode); gbFHH,@
} (^~~&/U_U$
+y 48.5
E/^N
//停止文件下载 ~{t<g;F
public void siteStop() .nei9Y*
{ 6N/6WrQEeg
bStop = true; ",S146Y+
for(int i=0;i<nStartPos.length;i++) ~@"H\):/
fileSplitterFetch.splitterStop(); 1CS\1[E
i8=+<d
I@(3~ Ab
} *~zB{
} $/Llzpvny
//负责部分文件的抓取 >Xxi2Vy
**FileSplitterFetch.java SjvSnb_3
*/ dfXBgsc6i
package NetFox; :\%ZTBLL
(b7',:_U7
iz27yXHZ~
import java.io.*; ziv*4
import java.net.*; e8k|%m<Sp
PD-*rG `
;/!o0:m^I
public class FileSplitterFetch extends Thread { 3E!3kSh|
pzT`.#N:M
d}@n,3
String sURL; //File URL @CKMJ^#|
long nStartPos; //File Snippet Start Position q( %)^C
long nEndPos; //File Snippet End Position ?',GRaD
int nThreadID; //Thread's ID !fJy7Y
boolean bDownOver = false; //Downing is over , Q)
boolean bStop = false; //Stop identical x}uDW
FileAccessI fileAccessI = null; //File Access interface $ou/ Fn
e1ExB#
$NBQv6#:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~pwk[Q!
{ ;S'1fci6
this.sURL = sURL; x}OJ~Yk]
this.nStartPos = nStart; NOl/y@#
this.nEndPos = nEnd; E=ObfN"ge
nThreadID = id; $|I hO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r%`3*<ALV)
} p &i+i
MSe>1L2=
AH^ud*3F
public void run() IB^vEY!`6_
{ S)`@)sr
while(nStartPos < nEndPos && !bStop) qCm8R@
{ VwT&A9&{8
.RWq!Z=)3
FaKZ|~Y e
try{ <'~6L#>,<
URL url = new URL(sURL); "7w=LhzV[$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?v&2^d4C*F
httpConnection.setRequestProperty("User-Agent","NetFox"); -gv[u,R
String sProperty = "bytes="+nStartPos+"-"; LRSt >; M
httpConnection.setRequestProperty("RANGE",sProperty); L#N]1#;
Utility.log(sProperty); lN*"?%<x>
+^[SXI^JaJ
5-:H
InputStream input = httpConnection.getInputStream(); `~h8D9G
//logResponseHead(httpConnection); ov1#BeQ
ob9=/ R?i
Xvxrz{
byte[] b = new byte[1024]; ,v#3A7"yW
int nRead; b:$q5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UGP&&A#T-
{ it->)?"(6
nStartPos += fileAccessI.write(b,0,nRead); b6@0?_n
//if(nThreadID == 1) %z-n2%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w=[ITQ|W%
} Wli!s~c5Fo
m(CsO|pz
(w Q,($@
Utility.log("Thread " + nThreadID + " is over!"); L8KaK
bDownOver = true; CUj$ <ay=
//nPos = fileAccessI.write (b,0,nRead); u|(Iu}sE=
} b\H,+|iK
catch(Exception e){e.printStackTrace ();} J4?SC+\
} xj JoWB
} VI)hA ^S
SU(J
xN6}4JB
//打印回应的头信息 fbkAu
public void logResponseHead(HttpURLConnection con) f2k~(@!h
{ DKG;up0
for(int i=1;;i++) Zk5AZ R!|
{ 6dYa07
String header=con.getHeaderFieldKey(i); iAXF;'|W
if(header!=null) 0<nW nD,z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tZ:fh p
Utility.log(header+" : "+con.getHeaderField(header)); z\Z+>A
else 2c3/iYCKP
break; WmE4TL^8?
} AA}+37@2I
} n`p/;D=?
bUc++M
hPt=j{aJ%<
public void splitterStop() ^CB@4$!
{ iN2591S
bStop = true; ucUuhS5
} #_zj5B38E
jIWX6
y 48zsm{
} /Ur]U w
Rj-4K@a8#N
^O**ZndB/
/* r<'B\.#tp>
**FileAccess.java %< Jj[F
*//文件访问(定位，写) %/R[cj8
package NetFox; /.(F\2+A
import java.io.*; FmQiy+.|
QG09=GQ
@`HW0Y_:
public class FileAccessI implements Serializable{ aQV?}
X&!($*/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6`5DR~
RandomAccessFile oSavedFile; QV _aM2
long nPos; _w7yfZLv+
h-\+# .YP
*?o 'sTH
public FileAccessI() throws IOException %%lJyLq'Vk
{ 9dp1NjOtAc
this("",0); #YSFiy:+r_
} }jYVB|2
isz-MP$:K5
{-yw@Kq
public FileAccessI(String sName,long nPos) throws IOException YyC$\HH6
{ "}:SXAZ5`
oSavedFile = new RandomAccessFile(sName,"rw"); !)FKF7'
this.nPos = nPos; m2Wi "X(I_
oSavedFile.seek(nPos); J?f7!F:8
} :v^OdW
/Y| <0tq
zn5|ewl@"
public synchronized int write(byte[] b,int nStart,int nLen) hdYd2 j
{ YH&0Vy#c$
int n = -1; D*ZswHT{y
try{ "1hFx=W+\
oSavedFile.write(b,nStart,nLen); 'w_Qs~6~{
n = nLen; P@U2Q%\
} l$C Y gm
catch(IOException e) *Q;?p hr
{ Y\E7nll:.
e.printStackTrace (); ~FnY'F<35
} ;V84Dy#b
`dIwBfg_
aO*v"^oF
return n; KuMH,rXF
} n{"a0O
l<yYfGO
Oki{)Ssy
} "fu@2y4^
I~,bZA
TmJXkR.5
/* fj[Kbo 7!h
**SiteInfoBean.java M} Mgz
*/ Zl?9ibm;@
package NetFox; , jCE hb
kk}_AZ0eK
l_P90zm39!
public class SiteInfoBean { U"L-1]L
BxB B](
zEw~t&:e
private String sSiteURL; //Site's URL Sp[]vm8N
private String sFilePath; //Saved File's Path Cw~fP[5XMF
private String sFileName; //Saved File's Name t_\&LMD
private int nSplitter; //Count of Splited Downloading File H"wIa8A
Rp6q)
=|H.r9-PK6
public SiteInfoBean() V2$M`|E
{//nSplitter的缺省值为5 '|G8yojz
//default value of nSplitter is 5 [x -<O:r=P
this("","","",5); {N@Pk[!
} G}@a]EGm
)g`~,3G
~Sx\>wBlc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6ck%M#v
{ 6u{%jSA>D\
sSiteURL= sURL; ]6,D9^{;
sFilePath = sPath; 3]kN9n{
sFileName = sName; ;dTxQ_:
this.nSplitter = nSpiltter; bl#6B.*=
%Hu.FS5'
#j"GS/y"
} v(P <_}G
m1M6N`f
6+:;Mb_S
public String getSSiteURL() 593!;2/@
{ ,Uy;jk
return sSiteURL; rnBp2'EM
} 3Qu-X\
T[2<_nn=
sk@aOv'*(
public void setSSiteURL(String value) d"thM
{ nY,LQ0r
sSiteURL = value; |Gr@Mi5
} o 80x@ &A:
{HjJ9ZGQ
c!mMH~#
public String getSFilePath() WnA Y<hZ|
{ N3wy][bo
return sFilePath; hz5t/E
} 2%)~E50U
gOy{ RE
o Va[
public void setSFilePath(String value) bl\;*.s'
{ :bXTV?#0
sFilePath = value; t|*UlTLm
} G^#?~
[C@Ro,mI
\p!m/2
public String getSFileName() l|M|;5TW
{ }Ggn2 X
return sFileName; -jVg{f!
} $_gv(&ZT
iDYm4sY
M%s!qC+
public void setSFileName(String value) )/Oldyp
{ gl!ht@;>ak
sFileName = value; {~#d_!(
} =nlj|S ~3
^cuH\&&7
/'^BHA|h
public int getNSplitter() "tu*(>'~5
{ W!1 B~NH#
return nSplitter; k7M{+X6[
} 7**zO3 H
::@JL
J!}R>mR
public void setNSplitter(int nCount) ajX] ui
{ #hXuGBZEI
nSplitter = nCount; !04^E
} }&%&0$%
} |*L/ m0'L
845\u&
&iT^IkA{
/* &uI33=
**Utility.java ER:K^ Za
*/ (U:6vk3Q
package NetFox; >E WK cocM
3M>y.MS
milQxSpj
public class Utility { 1/SB[[g
GE\({V.W
1U ='"
public Utility() ~eUv.I/
{ ^c|0?EH
m~F ~9&
0\+$j5;
} c$_}
4x.I"eW~&
//线程睡眠 lE3&8~2
public static void sleep(int nSecond) 7r pTk&`
{ sR| /s3;
try{ 7>-99o^W
Thread.sleep(nSecond); l s%'\}
} 6L2Wv5C
catch(Exception e) i'}"5O+
{ 2SKtdiY
e.printStackTrace (); ;`Z>^.CB
} B9'2$s+Z;
} S}K-\[i?
'Y/8gD~.
//日志 .[Ny(X/]/}
public static void log(String sMsg) Gz7,g Y
{ &+/$~@OK
System.err.println(sMsg); Zm#,Ike?#
} '@"A{mrE
<XzRRCYQ
='(;!3ZH
public static void log(int sMsg) EpENhC0
{ vb`:
System.err.println(sMsg); /}s#
} '(8} <(%
} ryTtGx%a
l{V(Y$xp3
V_KHVul
/* X$ A ]7t
**TestMethod.java =HMuAUa.
*/ YW"nPZNPy~
package NetFox; nDNK}O~'
'f6!a5qC
O\w-hk
public class TestMethod { bLUyZ3m!
<O{G&
6lwWFR+k
public TestMethod() VGOdJ|2]Wr
{ ///xx/weblogic60b2_win.exe 8,:lw3x1
try{ %gTY7LIe1z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pzU:AUW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'JAe=K H
SiteFileFetch fileFetch = new SiteFileFetch(bean); >8injW352
fileFetch.start(); "p&4Sn3T2?
} Dj w#{WR
catch(Exception e){e.printStackTrace ();} W;8}`k
s_6Iz^]I
H#QPcp@
} GGFrV8
Z FIgKWZ'
7Ur'@wr
public static void main(String[] args) {tnhP^C3>
{ :kucDQE({?
new TestMethod(); Qq\hD@Z|
} U"K%ip:Wd
} +b{tk=Q:
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