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)); Dbn~~P
} 45biy(qa
for(int i=0;i<nEndPos.length-1;i++) C).\ J !
{ 1V,@uY)s
nEndPos = nStartPos[i+1]; |k~AGc
} ,X/j6\VBO
nEndPos[nEndPos.length-1] = nFileLength; {^oohW -
} |>}CoR7
} 8YZ9
-gGw_w?)(
q&=z^Ln!G
//启动子线程 ?EUg B\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 23CvfP
for(int i=0;i<nStartPos.length;i++) ;8[VCU:
{ +~=a$xA[C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K2*rqg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ET^?>YsA
nStartPos,nEndPos,i); POk5+^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gI7*zR4D
fileSplitterFetch.start(); Zwq\m.h
} bEF2-FO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E$lbm>jsb$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v[|-`e*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #j7&2L
nEndPos = " + nFileLength); cQ1[x>OcU
// fileSplitterFetch[nPos.length-1].start(); Wm1dFf.>
\asn^V@"zz
l!gX-U%-
//等待子线程结束 5voL@w>
//int count = 0; 1Z0Qkd(
//是否结束while循环 H%vgPQ8
boolean breakWhile = false; p7AsNqEp
I3 6@x`f
j![1
while(!bStop) b81^756
{ Wx}-H/t'2
write_nPos(); :Xy51p`.;]
Utility.sleep(500); 4wv0~T$;x
breakWhile = true; ;8=Bee4
F u5zj\0J
S?Cd,WxT
for(int i=0;i<nStartPos.length;i++) *_YH}U
{ K!AA4!eUzM
if(!fileSplitterFetch.bDownOver) X\BFvSv8C
{ U;kNo3=
breakWhile = false; Wlg1t~1=
break; pj7al;
} H|e7IsY%
} L_T+KaQCH
if(breakWhile) ^PC;fn,I
break; LRw-I.z
|L89yjhWBs
x?rd9c
//count++; k]AL\) &W
//if(count>4) ^fN/
// siteStop(); ouyZh0G
} 7[ n |3
>KQ/ c
> {d9z9O
System.err.println("文件下载结束！"); S -,$ (
} IRR b^Q6
catch(Exception e){e.printStackTrace ();} uEhPO
} C[{E8Tg/
&hZ.K"@7{
n4B uM R
//获得文件长度 b7+(g[O
public long getFileSize() Z6M qcAJ3j
{ fHwS12SB
int nFileLength = -1; nm_taER
try{ C \5yo
URL url = new URL(siteInfoBean.getSSiteURL()); ve"tbNL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^} Y}Iz
httpConnection.setRequestProperty("User-Agent","NetFox"); [uJS.`b
YnU*MC}
~Hd*Xl
int responseCode=httpConnection.getResponseCode(); Jw;G_dQ[
if(responseCode>=400) X%og}Cfi
{ wmX(%5vY^
processErrorCode(responseCode); !K2QD[x
return -2; //-2 represent access is error cM<08-:v
} YuHXm3[
[_ uT+q3
TtWzjt
String sHeader; NBBR>3nt
s`G}MU
2B)1 tP
for(int i=1;;i++) 4\ElMb[]
{ Z;tWV%F5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I!(BwYd
//Utility.log(in.readLine()); T#:b
sHeader=httpConnection.getHeaderFieldKey(i); ~PAI0+*"q
if(sHeader!=null) WAtv4
{ m$hkmD|
if(sHeader.equals("Content-Length")) " o3Hd
{ <Voct
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +BhJske
break; n _x+xVi%
} &Cm]*$?
} g-ZXj4Ph!
else GjN6Af~}
break; ZP@NV|B
} ;bHS^
} iv],:|Mbd
catch(IOException e){e.printStackTrace ();} ~>_UTI
catch(Exception e){e.printStackTrace ();} bVa?yWb.
SjF(;0kC
KW ZEi?
Utility.log(nFileLength); wZJbI[r
~J#Z7y]p!j
AOwmPHEL
return nFileLength; %] :ZAmN
} Akws I@@
Jf#-OlEQ
_ShWCU-~Z
//保存下载信息（文件指针位置） (c"!&&S^ =
private void write_nPos() VfDa>zV3
{ se]&)%p[
try{ Z( "-7_
output = new DataOutputStream(new FileOutputStream(tmpFile)); oSjYp(h:
output.writeInt(nStartPos.length); f<|*^+
for(int i=0;i<nStartPos.length;i++) <9:~u]ixt
{ 9:=:P>
// output.writeLong(nPos); ?<\2}1
output.writeLong(fileSplitterFetch.nStartPos); Bu?Qyz2O
output.writeLong(fileSplitterFetch.nEndPos); M)Z!W3
} jaavh6h)
output.close(); gNDMJ^`
} qzO5p=}
catch(IOException e){e.printStackTrace ();} Tdz#,]Q
catch(Exception e){e.printStackTrace ();} PRFl%M.H`
} ^ZRZ0:rZ
*DZ7,$LQ~D
iTT%_-X-
//读取保存的下载信息（文件指针位置） |;d#k+/;
private void read_nPos() T2tvU*[=
{ {^:NII]
try{ 6R$Yh0%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !;d>}iE
int nCount = input.readInt(); % -+7=x
nStartPos = new long[nCount]; ">20`Mj8
nEndPos = new long[nCount]; Ho[]03
for(int i=0;i<nStartPos.length;i++) T{-gbo`Yji
{ (ov&iNx
nStartPos = input.readLong(); TiG?r$6v%
nEndPos = input.readLong(); ?2\oi*$
} >El]5M7h7
input.close(); j+q)
} oe3=QE
catch(IOException e){e.printStackTrace ();} l%?4L/J)#
catch(Exception e){e.printStackTrace ();} ,w9|?%S
} .)p%|A#^
.c@Y?..+
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private void processErrorCode(int nErrorCode) #T{)y
{ h;y}g/HZ
System.err.println("Error Code : " + nErrorCode); VN\VTSZh?\
} #sg dMrVQ
s16, *;Z
;O{bF8U
//停止文件下载 @#-\BQ;
public void siteStop() |-S+x]9
{ (\r^0>H
bStop = true; P>_9>k@;Q
for(int i=0;i<nStartPos.length;i++) ZJF+./vN
fileSplitterFetch.splitterStop(); h+&iWb3;
?E}gm>
BSB&zp
} 4~ L1~Gk
} r ?<kWR?w
//负责部分文件的抓取 mO(Y>|mm
**FileSplitterFetch.java v,z~#$T&
*/ ^;9l3P{
package NetFox; Dv`"3
C+jXH)|iq
UIg?3J}R
import java.io.*; kzNRRs\e
import java.net.*; Z#(Y%6[u
) j&khHD
9ZatlI,
public class FileSplitterFetch extends Thread { ;*9<lUvu
7/k7V)
kumo%TXB&
String sURL; //File URL %hw4IcWJ|
long nStartPos; //File Snippet Start Position S'w}Ir
long nEndPos; //File Snippet End Position 5K682+^5
int nThreadID; //Thread's ID C!9mygI
boolean bDownOver = false; //Downing is over skTaIGRL
boolean bStop = false; //Stop identical yJO Jw o^
FileAccessI fileAccessI = null; //File Access interface &)JoB
@,;h!vB*=
UJ%.KU%Q}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tX@y ]"
{ e6tU8`z
this.sURL = sURL; m .(\u?J
this.nStartPos = nStart; A-_M=\
this.nEndPos = nEnd; Kb;Pd!Q
nThreadID = id; X&5N89
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NZADHO@0
} B]}gfVO
C.LAr~P
iC^G^~V+H
public void run() FwHqID_!:l
{ Qb%; |li
while(nStartPos < nEndPos && !bStop) ?u".*!%
{ ~)>.%`v&
[cZ/)tm
>"b\$",~6
try{ llh +r?
URL url = new URL(sURL); &+ PVY>q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i O?f&u
httpConnection.setRequestProperty("User-Agent","NetFox"); p[At0Gc L
String sProperty = "bytes="+nStartPos+"-"; !O}e)t
httpConnection.setRequestProperty("RANGE",sProperty); 9n_RkW5g
Utility.log(sProperty); 3fXrwmBT8
%21|-B
kq?:<!z
InputStream input = httpConnection.getInputStream(); x>BFK@#
//logResponseHead(httpConnection); }Y!s:w#
_/cX!/"
@2d9 7.X
byte[] b = new byte[1024]; +ug/%Iay{k
int nRead; matm>3n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :V#xrH8R
{ aK|
nStartPos += fileAccessI.write(b,0,nRead); z j#<X
//if(nThreadID == 1) uR.pQo07y<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ! 9*l!(
} $ve$Sq
'W54 T
u8|CeA
Utility.log("Thread " + nThreadID + " is over!"); On!+7is'
bDownOver = true; 4MW oGV9
//nPos = fileAccessI.write (b,0,nRead); wxj}k7_(`A
} aUc#,t;Qd
catch(Exception e){e.printStackTrace ();} -a~n_Z>_
} Iw( wT_
} eLXL5&}`fh
1uG)U)y/Q
s~B)xYmyB'
//打印回应的头信息 SK@ p0:
public void logResponseHead(HttpURLConnection con) 8'TIDu
{ H]wP\m)
for(int i=1;;i++) V:P]Ved
{ '/0e!x/8
String header=con.getHeaderFieldKey(i); .HqJ)OH
if(header!=null) wmXI8'~F&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); opN4@a7l
Utility.log(header+" : "+con.getHeaderField(header)); +|pYu<OY
else LN<rBF[_:f
break; 7,Z<PE
} w,R6:*p5
} #<sK3PT
c{?SFwgd
8)pL0bg
public void splitterStop() $""kZ
{ Lpkx$QZ
bStop = true; ~Jw84U{$
} gYk5}E-
}opMf6`w
k W 8>VnW
} iPWr-
Y= =5\;-
>m<T+{`
/* 3ZyvX]@_
**FileAccess.java /4;A.r`;
*//文件访问(定位，写) 1x\k:2U
package NetFox; 1MnC5[Q
import java.io.*; U,6sR
IqsUtWSp
a'Zw^g
public class FileAccessI implements Serializable{ zOFHdd ,"g
}oSgx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T:2f*!r
RandomAccessFile oSavedFile; _29wQn@]
long nPos; *vIP\NL?H
g"Ueo'd*
z\8s |!
public FileAccessI() throws IOException :Mh\;e
{ P6ktA-Hv>
this("",0); x^pt^KR;
} @V5i
-%%Xx5D
W+U0Y,N6
public FileAccessI(String sName,long nPos) throws IOException ^q&|7Ou-
{ e"bzZ!c&~V
oSavedFile = new RandomAccessFile(sName,"rw"); B)L0hi
this.nPos = nPos; IO=$+c
oSavedFile.seek(nPos); l`A&LQ[
} l Ib d9F
7ZyP
a8ouk7G
public synchronized int write(byte[] b,int nStart,int nLen) 4e AMb
{ zb"4_L@m2
int n = -1; UpE+WzY
try{ /^\E:(RH
oSavedFile.write(b,nStart,nLen); 74:~F)BP
n = nLen; =_N[mR^
} /3SEu(d!
catch(IOException e) j3N d4#
{ 'kY/=*=Q
e.printStackTrace (); &IzNoB
} |:x,|>/
)1Y?S;
oD\t4]?E
return n; uPr!;'J=
} 9\WtcLx
E"S#d&9
i$6rnS&C
} ">3t+A
|&W4Dkn
_(8#
/* Cojs;`3iF:
**SiteInfoBean.java ]adgOlM
*/ Do\j_
package NetFox; =7H\llL4BC
_E'}8.#{
_6r[msH"
public class SiteInfoBean { ~xsJML
\~+b&
8M,@Mbn
private String sSiteURL; //Site's URL $':5uU1}
private String sFilePath; //Saved File's Path uYg Q?*Z
private String sFileName; //Saved File's Name jXALL8[c
private int nSplitter; //Count of Splited Downloading File jnztCNaX
;]m;p,$
r4K9W90
public SiteInfoBean() Tsb}\
{//nSplitter的缺省值为5 T$R#d&t
//default value of nSplitter is 5 %W7%]Z@j
this("","","",5); phf{b+'#X
} _b-g^#L%
D86F5HT}}
4^:dmeMZ`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7 L,`7k|
{ '<<@@.(f
sSiteURL= sURL; j nSZ@u
sFilePath = sPath; DeNWh2
sFileName = sName; *C+[I
this.nSplitter = nSpiltter; k\T]*A
Q%?%zuU
LiQH!yHW
} @%L
tKLeq(
!> +Lre@
public String getSSiteURL() Vq`/]&
{ 4~$U#$u_
return sSiteURL; dJnKa]X
} MmvOyKNZF
*!BQ1] G
\#w8~+`Gq
public void setSSiteURL(String value) @jMo/kO/A
{ m,q)lbRl
sSiteURL = value; 1D8S}=5&
} ~'0n ]Fw
DA>nYj-s
Nb_Glf
public String getSFilePath() Vraz}JV
{ n[K%Xs)
return sFilePath; -X%twy=
} P{`fav
Oe@w$?
noa+h<vGb
public void setSFilePath(String value) +`Nu0y!rj
{ 9IG<9uj
sFilePath = value; o_Y?s+~i[/
} &Fuk+Cu{
Sw-2vnSdM
OiZ-y7;k^
public String getSFileName() U*sQ5uq
{ <im}R9eJ1
return sFileName; #EE<MKka
} 6}c!>n['
eS ?9}TG|
T8&sPt,f
public void setSFileName(String value) T>#~.4A0
{ +cmi?~KS*
sFileName = value; Hi~)C\
} =+DhLH}8
MwSfuP
.:Wp9M
public int getNSplitter() <^KW7M}w*c
{ 4A(h'(^7A
return nSplitter; z+wegF
} T9r6,yY
#X$s5H
Zj ^e8u=T
public void setNSplitter(int nCount) 5{1=BZftZ
{ b{-|q6
nSplitter = nCount; :cXN Fu\C
} j%]sym
} x00'wY|
7!Im|7Ty
w}$;2g0=a<
/* ?-`&YfF
**Utility.java ;KmrBNF
*/ !-%%94Q
package NetFox; b~)2`l
&P35\q
Q/j#Pst
public class Utility { En&gI`3n
IFa~`Gf[
BAi0w{
public Utility() :h3U^
{ L|-|DOgw
? }`mQ<~
+eLL)uk
} D88IU9V&n
u%"5<ll
//线程睡眠 u:l<NWF^
public static void sleep(int nSecond) itiSZL,
{ )g3c-W=
try{ #(+V&<K
Thread.sleep(nSecond); H`q[!5~8
} %i?v)EW
catch(Exception e) {KEmGHC4R
{ eHd7fhW5
e.printStackTrace (); v|]"uPxH?
} U^)`_\/;?
} lU$0e09
Qr6PkHU
//日志 e$`hRZ%
public static void log(String sMsg) "K+EZ%~<
{ %CgV:.,K
System.err.println(sMsg); hK{<&T
} ;/+U.I%z
H5UF r,t
S>j.i
public static void log(int sMsg) 0XqxW\8_l
{ Vu E$-)&)
System.err.println(sMsg); ?FR-aXx
} D$NpyF.87
} 9v8^uPA
Y"m(hs$
ub`zS-vb
/* cJTwgm?
**TestMethod.java kh#fUAt
*/ puMbB9)
package NetFox; _.BT%4
N&Ho$,2s
?gjx7TQ?
public class TestMethod { tp&|*M3
=]"I0G-s!
MQ0rln?
public TestMethod() ?`O^;f
{ ///xx/weblogic60b2_win.exe G\V*j$}!
try{ n"Bc2}{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \ a(ce?C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iXvrZofE
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y#=MN~##t
fileFetch.start(); rcY &n^:
} E\;%,19Ob
catch(Exception e){e.printStackTrace ();} 3hUP>F8
<dr2 bz
u3pFH(
} ;_E|I=%'E
OIjSH~a.
WLfDXx2A
public static void main(String[] args) }@tgc?CD
{ S'hUh'PZ
new TestMethod(); ;/JXn
} #k`gm)|
} i27)c)\BM
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