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)); UYtuED
} aRJ>6Q}
for(int i=0;i<nEndPos.length-1;i++) 02k4N%
{ xlR2|4|8
nEndPos = nStartPos[i+1]; 35x 0T/8
} 2.X"f
nEndPos[nEndPos.length-1] = nFileLength; UP{j5gR:_
} Y}DonF
} @MK"X}3
%,*G[#*&
rBN)a"
//启动子线程 G^1b>K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vkRi5!bR
for(int i=0;i<nStartPos.length;i++) :p4"IeKs
{ L~^*u_U]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M-uMZQe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lRP1&FH0
nStartPos,nEndPos,i); iYbX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cubk]~VD
fileSplitterFetch.start(); n!E2_
} *X38{rj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2spg?]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =4 X]gW
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ij'NC C
nEndPos = " + nFileLength); 47T}0q,
// fileSplitterFetch[nPos.length-1].start(); do ^RF<G
:` $@}GI
m2Uc>S
//等待子线程结束 ~/tKMS6T
//int count = 0; }p9F#gr
//是否结束while循环 M'1!<a-Mp
boolean breakWhile = false; j,2l8?
da$BUAqU
^SfS~GQ
while(!bStop) e|r0zw S
{ ARfRsPxr
write_nPos(); k 2%S`/:
Utility.sleep(500); -NBiW6b~
breakWhile = true; \BI/G
|k{-l!HI
?Jtg3AY
for(int i=0;i<nStartPos.length;i++) oT|m1aGE
{ w h$jr{
if(!fileSplitterFetch.bDownOver) gK3Mms]}m
{ - n6jG}01b
breakWhile = false; RX2{g^V7
break; s-VSH
} fH8!YQG8$
} &VWlt2-R0h
if(breakWhile) Ld|V^9h1;
break; ~L+]n0*
g9my=gY
4rU!4l
//count++; ^`qPs/b
//if(count>4) em]xtya
// siteStop(); &4$oudn
} v&MU=Tcqi
r5/R5Ga^
u>Ki$xP1
System.err.println("文件下载结束！"); ZZ)G5ji
} swpnuuC-
catch(Exception e){e.printStackTrace ();} "L2m-e6
} ;' e@t8i6
}IlP:
e"+dTq8W
//获得文件长度 cQFR]i
public long getFileSize() twk&-:'
{ f3 ]
int nFileLength = -1; rvwy~hO"
try{ 3,.% s
URL url = new URL(siteInfoBean.getSSiteURL()); -0,4egj3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +EASAq
httpConnection.setRequestProperty("User-Agent","NetFox"); 8kW/DcLE
%TK&)Q% h5
4^!4eyQ^
int responseCode=httpConnection.getResponseCode(); w&lZ42(mF
if(responseCode>=400) s=EiH
{ ;>2#@QP
processErrorCode(responseCode); vg8O] YF
return -2; //-2 represent access is error ?G/hJ?3
} +CTmcbyOi
Ds5NAp:x
^@}#me@
String sHeader; 9[|4[3K
(buw^ ,NwZ
@%@zH%b
for(int i=1;;i++) FUaNiAr[
{ ,{j4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +*t|yKO>[
//Utility.log(in.readLine()); .T3=Eq&"W
sHeader=httpConnection.getHeaderFieldKey(i); Z%v6xP.
if(sHeader!=null) jFj~]]j
{ D&[Z;,CHMA
if(sHeader.equals("Content-Length")) [{PqV):p
{ U7%28#@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4=p@2g2"H
break; }#b %"I0
} Y5jYmP<
} If}lJ6jZ
else ;1LG&h,K
break; U4wpjHg
} i;lE5
} _9h.Gt
catch(IOException e){e.printStackTrace ();} [b5(XIGUN}
catch(Exception e){e.printStackTrace ();} t]TyXAr~
XN;/nU
pVOI5>f\
Utility.log(nFileLength); E8tD)=1
y-cw~kNPP3
[(cL/_
return nFileLength; ,z66bnjO
} (G5xkygR9
m,NMTyJoz
Mj~${vj
//保存下载信息（文件指针位置） V<$*Y>;
private void write_nPos() [$2qna2VP
{ t&"5dM\
try{ 2xmT#m
output = new DataOutputStream(new FileOutputStream(tmpFile)); <PD|_nZT
output.writeInt(nStartPos.length); &N{zkMf
for(int i=0;i<nStartPos.length;i++) ?0npEz|
{ )Z:m)k>r;
// output.writeLong(nPos); ~.Q4c*_b
output.writeLong(fileSplitterFetch.nStartPos); $j !8?
output.writeLong(fileSplitterFetch.nEndPos); !3KPwI,
} z^~U]S3
output.close(); .S|-4}G(6
} 3LrsWAz'
catch(IOException e){e.printStackTrace ();} J<_1z':W)
catch(Exception e){e.printStackTrace ();} XZ@>]P
} &PWf:y{R`
x<Se>+
{Tx 3$eU
//读取保存的下载信息（文件指针位置） H^v{Vo
private void read_nPos() n^6TP'r
{ \DyKtrnm%
try{ gDhl-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ype"7p\
int nCount = input.readInt(); Y:%"K
nStartPos = new long[nCount]; i;HH ! TaN
nEndPos = new long[nCount]; V~c(]K)-
for(int i=0;i<nStartPos.length;i++) kGj]i@(PA4
{ o*)@oU
nStartPos = input.readLong(); drX4$Kdf]
nEndPos = input.readLong(); STp!8mL
} 5V rcR=?O
input.close(); Q=XA"R
} t>@yv#
catch(IOException e){e.printStackTrace ();} D'?]yyrf
catch(Exception e){e.printStackTrace ();} \I xzdFF#
} 0nT%Slbih
ct.Bg)E
b.(XS?4o
private void processErrorCode(int nErrorCode) T]X{@_
{ G,/Gq+WX
System.err.println("Error Code : " + nErrorCode); q"p#H8
} !pV<n
1G_xP^H!
a}GAB@YI
//停止文件下载 R]VTV7D
public void siteStop() |3|wdzV
{ *e,CDV
bStop = true; YrKFa%k
for(int i=0;i<nStartPos.length;i++) 5EfY9}dl
fileSplitterFetch.splitterStop(); mN7&%Z
9 G((wiE
z.A4x#>-
} k2wBy'M.'
} Z#@6#S`
//负责部分文件的抓取 5#BF,-Jv
**FileSplitterFetch.java >VypE8H]x
*/ 9OhR41B
package NetFox; r"1A`89
c_[ JjG^?P
F94V5_[
import java.io.*; L<"k7)k
import java.net.*; YN`UTi\s
x:vrK#8D>
4&H+hN{3
public class FileSplitterFetch extends Thread { TVj1C
gBfX}EK7F
#VQ36pCd
String sURL; //File URL ! 7Nn]Lx
long nStartPos; //File Snippet Start Position 3lyQn"
long nEndPos; //File Snippet End Position _i.({s&_9
int nThreadID; //Thread's ID I@+lFG
boolean bDownOver = false; //Downing is over ,$o-C&nC
boolean bStop = false; //Stop identical dY 6B%V
FileAccessI fileAccessI = null; //File Access interface (J/>Gy)d
d[yrNB6|
r \9:<i8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i~(#S8U4d
{ cyDiA(ot&
this.sURL = sURL; ~S!L!qY
this.nStartPos = nStart; -aA<.+
this.nEndPos = nEnd; # e$\~cPd
nThreadID = id; Y]?Kqc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]C+eJ0"A
} 2}ag_
Lq3(Z%
THb A(SM
public void run() dzpj9[
{ ~igRg~k:/
while(nStartPos < nEndPos && !bStop) |F3vRt@
{ EmYO5Whi
_dz+2au
2c!h2$w
try{ f*UBigk
URL url = new URL(sURL); >_n:_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4b]IazL)
httpConnection.setRequestProperty("User-Agent","NetFox"); J,MT^B
String sProperty = "bytes="+nStartPos+"-"; gjO *h3`
httpConnection.setRequestProperty("RANGE",sProperty); wYC9~ms-
Utility.log(sProperty); r .{rNR
}FuVY><l
v4X_v!CQ
InputStream input = httpConnection.getInputStream(); _QD/!~O
//logResponseHead(httpConnection); p.qrf7N$
9 J$Y,Z
Qu!OV]Cc
byte[] b = new byte[1024]; ;>cLbjD
int nRead; gCjH%=s
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R>^5$[
{ 1{= E?
nStartPos += fileAccessI.write(b,0,nRead); +k#mvPq
//if(nThreadID == 1) i%#th'C!P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5R$=^gE
} :Fw *r|
?S+/QyjcfJ
p{+tFQy
Utility.log("Thread " + nThreadID + " is over!"); i.B$?cr~
bDownOver = true; {\ A_%
//nPos = fileAccessI.write (b,0,nRead); ^[k6]1h
} K'>P!R:El
catch(Exception e){e.printStackTrace ();} l!xgtP K
} IEKMa
} [YL sEo=
W66}\&5
^!zJf7(+<>
//打印回应的头信息 /DgT1^&0
public void logResponseHead(HttpURLConnection con) <FMuWHY
{ J@=!w[v+
for(int i=1;;i++) $`cy'ZaF
{ s|Imz<IE
String header=con.getHeaderFieldKey(i); {X{01j};8
if(header!=null) %Z-TbOX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #c8"
Utility.log(header+" : "+con.getHeaderField(header)); C?_t8G./_
else &utS\-;G
break; Pl`Bd0
} W$x K^}
} n^g-`
t!+%g) @
7$E2/@f
public void splitterStop() %3#b6m~
{ CNpCe-%&
bStop = true; A5(kOtgiT
} SLbavP#G
|V*e2w
)wyu+_:
} N^@%qUvT]
ur,V>J<5A
gK]T}
/* 'Q^G6'(SaK
**FileAccess.java \oD=X}UQw(
*//文件访问(定位，写) rzc 3k~@
package NetFox; % B7?l
import java.io.*; AZBY, :>D
]G$!/vXP
2=/-d$
public class FileAccessI implements Serializable{ -NI@xJO4(;
&**.naSo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RQ_#rYmT
RandomAccessFile oSavedFile; ~a0d.dU
long nPos; r;5 AY
]VO,} `
0^|$cvYiL
public FileAccessI() throws IOException j:\_*f
{ -h.3M0
this("",0); 7D9h;gsP
} A=l?IC@O
AH ?MJKY@Z
`zV-1)=
public FileAccessI(String sName,long nPos) throws IOException MXu+I,y*
{ E(L^hZMc
oSavedFile = new RandomAccessFile(sName,"rw"); $$)<(MP3
this.nPos = nPos; .WPuQZ!
oSavedFile.seek(nPos); )Uoe~\
} /Wta$!X{-
P89Dg/P
:W1tIB
public synchronized int write(byte[] b,int nStart,int nLen) hyr5D9d
{ _^,[wD
int n = -1; RvZryA*vu
try{ 'ra_Zg[j
oSavedFile.write(b,nStart,nLen); @b(gjOE
n = nLen; YC+ZVp"v
} //@sktHsw(
catch(IOException e) (kD?},Z
{ _j?=&tc
e.printStackTrace (); tL 9e~>,`
} 55)ep
xDAA`G
{U2|):
return n; ]'z^Kt5S
} :EmMia-)J
Ky{I&}+R|
:O_<K&
} Yru1@/;
#0$eTdx#
PSt|!GST
/* TBLk+AR
**SiteInfoBean.java 8Gzs
*/ =z7Ay
package NetFox; n ;$}pg~
pRyS8'
::h02,y;1%
public class SiteInfoBean { Ts?>"@
KfI$'F #"/
;z=C^'
private String sSiteURL; //Site's URL I n%yMH8
private String sFilePath; //Saved File's Path 1Y"y!\t7G
private String sFileName; //Saved File's Name GCmVmOdKr
private int nSplitter; //Count of Splited Downloading File *1 eTf
'3kL=(
aABE= 9Y
public SiteInfoBean() we@En .>f
{//nSplitter的缺省值为5 (Su2\x
//default value of nSplitter is 5 0yEyt7 ~@
this("","","",5); )SZ,J-H08w
} 5=;I|l,
kv FOk
!D]6Cq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '}[L sU
{ c^/?VmCQ}
sSiteURL= sURL; nV6g]#~@
sFilePath = sPath; g960;waz3
sFileName = sName; ri_6wbPp
this.nSplitter = nSpiltter; `oI/;&
x'PjP1
\|4MU"ri
} J}`$WL:
)^a#Xn3z
[/`Hz]R
public String getSSiteURL() _TeRsA
{ iPi'5g(a
return sSiteURL; 2ZFKjj
} Gt*<?
,'0oj$~S:
tfU3 6PR
public void setSSiteURL(String value) /3HWP`<x
{ [T&y5"@
sSiteURL = value; UyfIAC$S
} ~\(>m=|C:H
+_K;Pj]x
dg@/HLZ
public String getSFilePath() :a<TV9?H0
{ %>}7$Y%
return sFilePath; Z["nY&.sI
} ~5?n&pF
U@ QU8
4BL,/(W] x
public void setSFilePath(String value) wOl-iN=
{ SYhspB
sFilePath = value; %3B>1h9N
} .0/Z'.c8
E;e2{@SX2K
iPL'JVPZ
public String getSFileName() YQd&rkr
{ bI0+J)
return sFileName; ~Am %%$
} 17i@GnbNb
.j@n6RyN
@ dU3d\!}
public void setSFileName(String value) 4'e8VI0
{ 'F<e)D?
sFileName = value; ^bw~$*"j#
} vX)Y%I
ap_+C~%+
?B4QTx9B
public int getNSplitter() /9^0YC;Y*
{ N.cRZm%
return nSplitter; |?b"my$g$
} s+t eYL#Zi
F4l6PGxF&\
QU;C*}0Zl
public void setNSplitter(int nCount) K&oO+G^f
{ K%@SS8!oy
nSplitter = nCount; DcM+K@1E4^
} `SbX`a0p2
} T$B4DQ
~x\Q\Cxp
@WE$%dr
/* mM%BO(X{=
**Utility.java mT$tAwzTC{
*/ "N"k8,LH
package NetFox; I!#^F1p1
6E&&0'm
Wm/k(R`O<
public class Utility { akoKx)(<
a{6|[aR
AFA*_9Ut
public Utility() aM1JG$+7G
{ YZJP7nN
AV`7>@
eW<hC(
} No+zw%l0E
$h f\ #'J
//线程睡眠 Nd)o1{I
public static void sleep(int nSecond) ?*dx=UI
{ ps J 1J
try{ j>M%?Tw
Thread.sleep(nSecond); FkkB#Jk4
} 0`=?ig_
catch(Exception e) $~\qoW<
{ c9k,Dc
e.printStackTrace (); B75SLK:h=
} c9={~
} Q&;qFv5-l
Q:=/d$*xd
//日志 k9?+9bExXA
public static void log(String sMsg) 40ZB;j$l
{ zYJxoC{
System.err.println(sMsg); '^AXUb
} (J#3+I
4 ETVyK|
nwVtfsb
public static void log(int sMsg) ] lTfi0}g_
{ 2%H(a)
System.err.println(sMsg); #$QY[rf=6
} ttRH[[E(
} zW.sXV,
9|DC<Zn&B#
IA!Kpg W
/* 6Z=H>w
**TestMethod.java ybkN^OEJ
*/ s|oU$?eA
package NetFox; Wn5]2D\vkT
["9$HL
('oUcDOFTS
public class TestMethod { JASn\z
Z2 4 m
@x4Dt&:"
public TestMethod() E$ rSrT(
{ ///xx/weblogic60b2_win.exe ~VKXL,.
try{ $T0[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); sP7(1)\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R~([
SiteFileFetch fileFetch = new SiteFileFetch(bean); C]cw@:o%
fileFetch.start(); @TDcj~oR?
} tp&iOP6O
catch(Exception e){e.printStackTrace ();} 4dAhJjhgD
}+1oD{
x.Y,]wis
} @YELqUb*
p IToy;]
p,/^x~m3a
public static void main(String[] args) bHM .&4G
{ yuBBO:\.
new TestMethod(); C~*m&,@TT^
} &$f?XdZ7
} 4YC`dpO'
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