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)); "ebn0<cZ
} w$2-t
for(int i=0;i<nEndPos.length-1;i++) \2~.r/`1
{ 's*UU:R
nEndPos = nStartPos[i+1]; _&yQW&vH#
} 4N*^%
nEndPos[nEndPos.length-1] = nFileLength; D:){T>
} +!w?g/dV
} #Xsby
W&rjJZY6
{9P<G]Z
//启动子线程 bXtA4O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Xf#uK\f
for(int i=0;i<nStartPos.length;i++) j8N8|\n-
{ fDqlN`P@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7O"T`>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qo'pU/@
nStartPos,nEndPos,i); 23Eg|Xk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >O~xu^N?
fileSplitterFetch.start(); :<nL9y jt
} :@Q_oyWE8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d[ {=/~0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1no$|n#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nar=\cs~g
nEndPos = " + nFileLength); cbS8~Xmj
// fileSplitterFetch[nPos.length-1].start(); }_u)3X.O
$KtMv +m"
.t\Yv/|`
//等待子线程结束 F2+lwycY
//int count = 0; NH|v`rO
//是否结束while循环 ysvn*9h+&
boolean breakWhile = false; h~<#1'/<
.llAiv
rJZ-/]Xf!6
while(!bStop) [D/q%
{ mz/KGZ5t
write_nPos(); |n]^gTJt
Utility.sleep(500); oq;}q
breakWhile = true; 6s>PZh
Qza[~6
;9b?[G
for(int i=0;i<nStartPos.length;i++) _*&<hAZj
{ qB"y'UW8
if(!fileSplitterFetch.bDownOver) +>/Q+nh
{ ]_#[oS
breakWhile = false; GVFD_;j'
break; EEF}Wf$f
} W*VQ"CW{^]
} g,x$z~zU{
if(breakWhile) w6Ue5Ix,!
break; g[!sGa&
'?Hy"5gUA
RU[{!E
//count++; I7]45pF
//if(count>4) @-Gf+*GZys
// siteStop(); a#KxjVM
} nj)M$'
g"<kj"
\#~~,k 6f
System.err.println("文件下载结束！"); gNe{P~ $=
} o$2fML
catch(Exception e){e.printStackTrace ();} BXLhi(.s
} n j1 cqh
mnG\UK,k
RkC?(p
//获得文件长度 .bew,92
public long getFileSize() &XN*T.Y`
{ T*LbZ"A
int nFileLength = -1; 5E~][. d
try{ ./.E=,j
URL url = new URL(siteInfoBean.getSSiteURL()); wxvt:==
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T,jxIFrF
httpConnection.setRequestProperty("User-Agent","NetFox"); ,ad~6.Z_)
0wxQ,PI1'
"<bL-k*H)
int responseCode=httpConnection.getResponseCode(); IHf A;&b
if(responseCode>=400) 8=t?rA
{ A9F&XF7{
processErrorCode(responseCode); TlAY=JwW
return -2; //-2 represent access is error FVL0K(V(
} |0mh*+i
33-=Z9|r
iZ)7%R?5
String sHeader; +^4"
dqPJ 2j $\
i_f"?X;D
for(int i=1;;i++) l,pq;>c9a
{ uV=rLDY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8={(Vf6
//Utility.log(in.readLine()); W9.ZhpM
sHeader=httpConnection.getHeaderFieldKey(i); Bqa%L.N2SS
if(sHeader!=null) :|P"`j
{ -O. MfI+
if(sHeader.equals("Content-Length")) pHKj*Y
{ )Z"7^i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9?l( }S`
break; (#7pGGp*E
} #_4L/LV
} `7+?1z
else 67Ge}6*2pd
break; YIt:_][*
} mn4j#-
} mqwN<:
catch(IOException e){e.printStackTrace ();} pLrNYo*d
catch(Exception e){e.printStackTrace ();} S\GG(#b!
h4!$,%"''
90teXxg=|
Utility.log(nFileLength); {/ZB>l@D>8
PDM>6U
Q >)?_O(
return nFileLength; 1*G7Uh@K}
} T3wR0,
@^#y23R U
u.$.RkNMQ
//保存下载信息（文件指针位置） G74<sD
private void write_nPos() fM \T^X
{ WY0u9M4
try{ 3p$ZHH.UP
output = new DataOutputStream(new FileOutputStream(tmpFile)); Qa(u+
output.writeInt(nStartPos.length); }+I 8l'
for(int i=0;i<nStartPos.length;i++) "fS9Nx3
{ _U/etlDTO
// output.writeLong(nPos); 2-UZ|y
output.writeLong(fileSplitterFetch.nStartPos); @q[-,EA9
output.writeLong(fileSplitterFetch.nEndPos); $F;$-2
} dID]{
output.close(); K.*zqQKlI|
} *s;$`8fM<
catch(IOException e){e.printStackTrace ();} 024*IoVZ
catch(Exception e){e.printStackTrace ();} c$@,*c 0n
} l.fNkLC#
;k(|ynXv
~d){7OG
//读取保存的下载信息（文件指针位置） (f $Y0;v>}
private void read_nPos() L.ndLd
{ Br1JZHgA
try{ q>!T*BQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m <aMb
int nCount = input.readInt(); &A=d7ASN=
nStartPos = new long[nCount]; uqX"^dn4u
nEndPos = new long[nCount]; <f8@Qij
for(int i=0;i<nStartPos.length;i++) Z37Z
{ ]N2'L!4|;
nStartPos = input.readLong(); `[57U,v
nEndPos = input.readLong(); ;,@3bu>r
} ]-L/Of6F)|
input.close(); B~yD4^
} ]wdudvS@6r
catch(IOException e){e.printStackTrace ();} C'*1w
catch(Exception e){e.printStackTrace ();} #q(BR{A>t
} SS(jjpe&,
75I*&Wl
{%b>/r
private void processErrorCode(int nErrorCode) umI#P,%[
{ u\smQhQGE
System.err.println("Error Code : " + nErrorCode); [sACPn$f
} {l\v J#r:
o NJ/AT
{RwwSqJ
//停止文件下载 &hjrJ/'^
public void siteStop() ~sMn/T*fv
{ VO. Y\8/
bStop = true; WNlWigwYl
for(int i=0;i<nStartPos.length;i++) LPewoAXO
fileSplitterFetch.splitterStop(); hFylQfd
;2#HM^Mu
LTBqXh
} wz>j>e6k`
} P8z++h
//负责部分文件的抓取 JFR,QUT
**FileSplitterFetch.java 4>$>XL1
*/ G4=%<+
package NetFox; 6;[iX`LL
V@e0VV3yx%
)x?F1/
import java.io.*; /HI#8
import java.net.*; ~cU,3g
NVJvCs)3f
z$%ntN#eNA
public class FileSplitterFetch extends Thread { ;l}TUo
vA(3H/)-
l&;#`\s!V
String sURL; //File URL Z~muQ c?
long nStartPos; //File Snippet Start Position wyvs#T
long nEndPos; //File Snippet End Position U%w?muJW
int nThreadID; //Thread's ID e,:@c3I
boolean bDownOver = false; //Downing is over > YN<~z-
boolean bStop = false; //Stop identical @qg=lt|(F
FileAccessI fileAccessI = null; //File Access interface ?Za1 b
cnhYrX^
Jq/([
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -L1{0{Z
{ HO&#Lv
this.sURL = sURL; W#-M|
this.nStartPos = nStart; sE-"TNONZ
this.nEndPos = nEnd; jc)D*Cf
nThreadID = id; pA1Tod
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *8X: fq
} :N%]<Mq
o5. q
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public void run() 0o(/%31]
{ QJ>+!p*
while(nStartPos < nEndPos && !bStop) g0_8:Gs}^
{ jNrGsIY$
j/dNRleab
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try{ !3?HpR/nV
URL url = new URL(sURL); YuLW]Q?v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Eh8.S)E
httpConnection.setRequestProperty("User-Agent","NetFox"); j YO#
String sProperty = "bytes="+nStartPos+"-"; v3.JG]zLpP
httpConnection.setRequestProperty("RANGE",sProperty); eUx|_*`
Utility.log(sProperty); Y~fds#y0
S(9fGh
=;^2#UxXA&
InputStream input = httpConnection.getInputStream(); ]7c715@
//logResponseHead(httpConnection); IuB0C!'
C!~&c7
Y/)>\
byte[] b = new byte[1024]; Jr\4x7a;`~
int nRead; v=9:N/sW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,%>/8*
{ LT#*nr
nStartPos += fileAccessI.write(b,0,nRead); FW=oP>f]w
//if(nThreadID == 1) AqE . TK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /,GDG=ra
} sh E>gTe
</qXKEu`_
T4J(8!7
Utility.log("Thread " + nThreadID + " is over!"); dM#\h*:=
bDownOver = true; lE$X9yIt
//nPos = fileAccessI.write (b,0,nRead); %'k^aqFL
} oy#Qj3M8=
catch(Exception e){e.printStackTrace ();} wGLZzqgq
} a&wl-
} BEifUgCh
z/6eP`jj
O6lj^
//打印回应的头信息 DoNbCVZ
public void logResponseHead(HttpURLConnection con) J?u@' "u
{ `?91Cw=`
for(int i=1;;i++) h ej
{ 1r|'n aiZ
String header=con.getHeaderFieldKey(i); n\wO[l)
if(header!=null) to]1QjW-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GC#3{71
Utility.log(header+" : "+con.getHeaderField(header)); b!ot%uZZ
else q\[f$==p
break; >%'|@75K
} /nGsl<
} 4~DFtWbf
hSo\
JEs?Rm1^.
public void splitterStop() b":cj:mxL
{ YM/GSSq
bStop = true; Rb|\!
} 1+.(N:) +
"qR qEpD%
"4oY F:h
} =<n+AqJ%
*siS4RX2
|*i0h`a
/* GC~Tfrf=r
**FileAccess.java T>.*c6I b
*//文件访问(定位，写) Abd&p N
package NetFox; UIovv%7zZ
import java.io.*; YPFjAQ
|SQ5Sb
u])N^AY"sj
public class FileAccessI implements Serializable{ 50uNgLs
/i"L@t)\t
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 YeptYW@xfw
RandomAccessFile oSavedFile; ]k " j
long nPos; !T#~.QP4
,*}SfCon
(7;}F~?h
public FileAccessI() throws IOException )&;?|X+p
{ uiPfAPZ
this("",0); .@gv}`>
} Y u8a8p|
nO,<`}pV
_<yJQ|[z~i
public FileAccessI(String sName,long nPos) throws IOException 'k{pWfn=<
{ 8{(;s$H~
oSavedFile = new RandomAccessFile(sName,"rw"); p4*VE5[?_+
this.nPos = nPos; o} YFDYi
oSavedFile.seek(nPos); |!aMj8i2
} Jp=ur)Dj
E,>/6AU
S XIo
public synchronized int write(byte[] b,int nStart,int nLen) Wg3y y8vIW
{ `Q' 0l},
int n = -1; 0ua.aL'
try{ zdlysr#
oSavedFile.write(b,nStart,nLen); k8Qm +r<p
n = nLen; =*~]lz__M
} B|/=E470G
catch(IOException e) cX9 !a,
{ 4 B"tz!
e.printStackTrace (); &CV%+
} pGc_Klq
%J5zfNe)&
^%VMp>s
return n; *[) b}?
} {AoH
CC;T[b&
c0sU1:e0
} Nv{r`J.
<w}YD @(f
'j 'bhG
/* }*4XwUM e
**SiteInfoBean.java /U4F\pZl
*/ C4H M
package NetFox; _?x*F?5=
$Y5R^Y
d3v5^5kU
public class SiteInfoBean { KB0HM
mJ2>#j;5f
R4.$9_ui
private String sSiteURL; //Site's URL lfba
private String sFilePath; //Saved File's Path y'?ksow
private String sFileName; //Saved File's Name 8J-$+ ;
private int nSplitter; //Count of Splited Downloading File =;#+8w=^
0>} FNRC
h:\WW;s[B
public SiteInfoBean() dO =fbmK
{//nSplitter的缺省值为5 oJE~dY$Q
//default value of nSplitter is 5 .bE+dA6:v
this("","","",5); ~Gx"gK0
} fjVGps$j
vq-Tq>
]:uJ&xUar
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `md)|PSU
{ r-&Rjg
sSiteURL= sURL; DgQw`D)+
sFilePath = sPath; .Zv@iL5
sFileName = sName; `dO)}}| y
this.nSplitter = nSpiltter; A\nL(Nd
Wnm?a!j5
$lz\te
} e"Kg/*Ji1
$9k7A 8K
fTQRn
public String getSSiteURL() IhoV80b
{ s tvI
return sSiteURL; yxP(|
} n]c6nX:'
0%$E^`
MHar9)$}
public void setSSiteURL(String value) cBs:7Pnp%
{ COvcR.*0F
sSiteURL = value; }q7rR:g
} ;;#28nV
//T1e7)
`}<x"f7.z
public String getSFilePath() hUN]Lm6M
{ =8:m:Y&|`G
return sFilePath; jYE<d&Cq
} {/d<Jm:
pm`BMy<5PU
*-0tj~)>
public void setSFilePath(String value) H <7r
{ ntK#7(U'
sFilePath = value; 0wL-Ak#v
} Z&BJ/qk \-
]U?)_P@}
,tqMMBwC~_
public String getSFileName() 3Run.Gv\
{ V/xGk9L~
return sFileName; eFJ .)Z
} *q**,_?;
|e49F
bWU4lPfP
public void setSFileName(String value) D&0y0lxI@
{ TrA&yXXL
sFileName = value; [l"|x75-
} 2|]pD
)\oLUuL`;
g+'=#NS}
public int getNSplitter() ^I2+$
{ mY!os91KoO
return nSplitter; =SMI,p&
} -CePtq`
.&Tcds
N<XS-XB,
public void setNSplitter(int nCount) ;;|S QX
{ =@BVO@z@
nSplitter = nCount; W>[0u3
} ;J<K/YdI
} 4I&e_b< 30
.%Pt[VQ
5MU-Eu|*>
/* dZ]['y%
**Utility.java !Miw.UmPm
*/ Y'n+,g
package NetFox; j'xk[bM
F<R+]M:fa
0_\@!#-sml
public class Utility { ?4QX;s7
m3Ma2jLWC
!mX-g]4E
public Utility() 2GRL`.1
{ MLVrL r t
rt +a/:4+
z#DgoA
} =]Gw9sge@
j_w"HiNBA
//线程睡眠 Eu;f~ V
public static void sleep(int nSecond) _c:}i\8R
{ G%Dhj)2}
try{ W.67};',
Thread.sleep(nSecond); A!xx#+M
} @B e7"Fm
catch(Exception e) Obj?,O
{ =H8 LBM
e.printStackTrace (); }fqz8'E9
} 3y9R1/!
} I;u1mywd
.A6i?iROe
//日志 fm u;Pb]r
public static void log(String sMsg) a8Va3Y
{ o'#ow(X
System.err.println(sMsg); A.[~}ywH
} ],.1=iY
DAvF ND$=
()cqax4
public static void log(int sMsg) ON()2@Y4
{ ;&K +x@
System.err.println(sMsg); g+:Go9k!F
} <r`^iR)%
} IXA3G7$)
V$OZC;4
cUB+fH<B2
/* >^odV ;^
**TestMethod.java =uG}pgh0
*/ BNj@~uC{
package NetFox; 4ju=5D];
7~f"8\
,\]`X7r
public class TestMethod { TAE@KSPvo
}I )%Gw
|O!G[|/3
public TestMethod() kuX{2h*`
{ ///xx/weblogic60b2_win.exe q2SlK8`QJ
try{ bxXNv^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); wr`+xYuuC=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -G|?Kl
SiteFileFetch fileFetch = new SiteFileFetch(bean); ZYMacTeJjg
fileFetch.start(); m,3H]
} x@aWvrL
catch(Exception e){e.printStackTrace ();} :"im2J
|<2g^ZK)
@)^|U"
} X`s6lV%\
,SZYZ 25
O3*}L2j@
public static void main(String[] args) dm:2:A8^
{ dX^d\ wX
new TestMethod(); awC:{5R8v
} 3<"!h1x5
} 1+Z@4;fk
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