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)); zk=\lp2
} e|'N(D}h*
for(int i=0;i<nEndPos.length-1;i++) !T'X 'Q
{ nq;#_Rkr
nEndPos = nStartPos[i+1]; X~RH^VYv
} wUp)JI
nEndPos[nEndPos.length-1] = nFileLength; P*G+eqX
} r4eUZ .8R
} RP` `mI
RJc%, ]:
dr})-R
//启动子线程 SRz&Nb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?~F. /
for(int i=0;i<nStartPos.length;i++) c8DZJSO
{ `ROEV~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Dip*}8$o(w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WC-_+9)2&
nStartPos,nEndPos,i); n33kb/q*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U9ZbVjqv@
fileSplitterFetch.start(); H_B~P%E@]
} =!<G!^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mG(N:n%*K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kRot7-7I|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T1NH eH>
nEndPos = " + nFileLength); p`>d7S>"
// fileSplitterFetch[nPos.length-1].start(); QN G&
*fhX*e8y
_t-7$d"
//等待子线程结束 '29WscU
//int count = 0; ;$!I&<)
//是否结束while循环 aWaw&u
boolean breakWhile = false; a%K}j\M
)HVcG0H1
Tsz NlRxc
while(!bStop) D ,M@8h,
{ M|%c(K#E,3
write_nPos(); |.w;r
Utility.sleep(500); arj$dAW
breakWhile = true; uO'/|[`8
,sDr9h/'C3
xzk}[3P{
for(int i=0;i<nStartPos.length;i++) z="L4
{ Y@}FL;3
if(!fileSplitterFetch.bDownOver) D4Sh9:\
{ uva\0q
breakWhile = false; =`p&h}h-L
break; l$XA5#k
} hC>wFC
} {;k_!v{
if(breakWhile) (cs~@
break; ]Oso#GYD
>saI+u'o
GS%b=kc
//count++; _01Px a2.
//if(count>4) A3s57.Z]|
// siteStop(); %#k,6;m
} |Fv?6qw+
$Jf9;.
r/AHJU3&eY
System.err.println("文件下载结束！"); GZ3/S|SMP
} CW0UMPE5
catch(Exception e){e.printStackTrace ();} Efr&12YSS
} >L[lV_M_>
C1QWU5c v
6%?A>
//获得文件长度 {tt$w>X
public long getFileSize() ~ hm`uP
{ JEHK:1^
int nFileLength = -1; qG9qN.|dC
try{ KO,_6>8]U
URL url = new URL(siteInfoBean.getSSiteURL()); treXOC9^B8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cyMs(21
httpConnection.setRequestProperty("User-Agent","NetFox"); 2 sSwDF
d8:C3R
Gah lS*W
int responseCode=httpConnection.getResponseCode(); yWHne~!
if(responseCode>=400) 2Xgx*'t\
{ ]kS7n@8
processErrorCode(responseCode); q^Inb)FeN
return -2; //-2 represent access is error ]{Ek[Av
} xIgql}.
6V;:+"BkJ
:6u~aT/
String sHeader; kF-TG3
lzfDH=&
ORH93`
for(int i=1;;i++) 0j$OE
{ hW%p#g;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \!wh[qEQ\
//Utility.log(in.readLine()); vlQ0gsXK
sHeader=httpConnection.getHeaderFieldKey(i); ^<;w+%[MT
if(sHeader!=null) RVP18ub.S
{ z!CD6W1n
if(sHeader.equals("Content-Length")) -N z}DW>
{ AbZ:(+@cP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XV5`QmB9
break; fuyl/bx}
} b-nYxd
} F< |c4
else a#QByP
break; rfTe
} XnY"oDg^>
} ]) n0MF)p
catch(IOException e){e.printStackTrace ();} ND*]gM
catch(Exception e){e.printStackTrace ();} BD'NuI
hbnS~sva
!KDr`CV&
Utility.log(nFileLength); +H}e)1^I
D3.VXuKn6
T6=-hA^A
return nFileLength; ;eh/_hPM
} ]xrD<
" $=qGHA~
(}0S1)7t
//保存下载信息（文件指针位置） #eLN1q&Z
private void write_nPos() OPiaG!3<
{ M.[wKGX(
try{ Ff)@L-Y\K
output = new DataOutputStream(new FileOutputStream(tmpFile)); P;c0L;/
output.writeInt(nStartPos.length); 8[HZ@@
for(int i=0;i<nStartPos.length;i++) NL-_#N$
{ R&!]Rl9hf
// output.writeLong(nPos); ,Hh*3rR^
output.writeLong(fileSplitterFetch.nStartPos); 4W-"|Z_x
output.writeLong(fileSplitterFetch.nEndPos); ^4UcTjh
} e YDUon
output.close(); -yA3 RP
} ;^ov~PPl
catch(IOException e){e.printStackTrace ();} >13/h]3
catch(Exception e){e.printStackTrace ();} l0#4Fma
} $WClpvVj
0etwz3NuW
nNs .,J)
//读取保存的下载信息（文件指针位置） M8_R
private void read_nPos() G"C;A`6
{ .qinR6=
try{ 9A<0zt
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mt^`1ekoY
int nCount = input.readInt(); InN{^uN
nStartPos = new long[nCount]; cD8Ea(
nEndPos = new long[nCount]; ,-:a?#f>
for(int i=0;i<nStartPos.length;i++) P57GqT
{ m9Il\PoTq
nStartPos = input.readLong(); g? I!OG
nEndPos = input.readLong(); ?OO%5PSen
} sW'6}^Q
input.close(); -%=RFgU4
} f?5A"-NS
catch(IOException e){e.printStackTrace ();} TZBVU&,{Z
catch(Exception e){e.printStackTrace ();} GoL|iNW`
} YM8rJ-
p}BGw:=
L]*`4L
private void processErrorCode(int nErrorCode) R9r)C{63S&
{ LUG9 #.
System.err.println("Error Code : " + nErrorCode); feN!_-
} j%u8=
E@mkm
,P~QS
//停止文件下载 !U[:5@s06
public void siteStop() Pv[ykrm/
{ FH[#yq.Pr
bStop = true; + "zYn!0
for(int i=0;i<nStartPos.length;i++) )r pD2H
fileSplitterFetch.splitterStop(); {s9<ej~<R
\H[Yyp4
M#T#:wf~
} qzHU)Ns(_
} ~.H~XKw
//负责部分文件的抓取 *F..ZS'$[
**FileSplitterFetch.java Onyh1
*/ n5\}KZh
package NetFox; <dS5|||
>'.[G:b
qZP:@r"
import java.io.*; _1\poAy
import java.net.*; 01o [!nT
%VS 2M #f
c l9$g7
public class FileSplitterFetch extends Thread { SlT7L||Ww
;tXY =
hWm0$v1p
String sURL; //File URL $i -zMa
long nStartPos; //File Snippet Start Position _}^u-fJ/~
long nEndPos; //File Snippet End Position $-e=tWkgv
int nThreadID; //Thread's ID SNN#$8\
boolean bDownOver = false; //Downing is over :S#i9# aB
boolean bStop = false; //Stop identical z:?:
FileAccessI fileAccessI = null; //File Access interface r\B"?oqC
qNy-o\;XN
N|o>%)R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1Lc8fP$
{ 0a@c/XGBp
this.sURL = sURL; CxkMhd8qz
this.nStartPos = nStart; nqrDT1b**
this.nEndPos = nEnd; >I|<^$/
nThreadID = id; 1B(G]o_>!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 PH[4y:^DN
} i:{:xKiCa
IE|,~M2
fmBkB8
public void run() 9V.+U7\w
{ /K[]B]1NE
while(nStartPos < nEndPos && !bStop) ^SgN(-QH
{ $.;iu2iyo
K(' 9l& A
k 5t{
try{ 'Z y{mq\
URL url = new URL(sURL); +<z7ds{Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fs7~NY
httpConnection.setRequestProperty("User-Agent","NetFox"); pRb<wt7v
String sProperty = "bytes="+nStartPos+"-"; }&C dsCM>2
httpConnection.setRequestProperty("RANGE",sProperty); u6f4yQ
Utility.log(sProperty); A_aO}oBX
fG3wc l~
L-j/R1fTvl
InputStream input = httpConnection.getInputStream(); y>4p~
//logResponseHead(httpConnection); ~6] )*y
$G)&J2zL
,Io0ZE>`V
byte[] b = new byte[1024]; NWeV>;lh9
int nRead; [@x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t&38@p
{ v [dAywW
nStartPos += fileAccessI.write(b,0,nRead); ?l(nM+[kSL
//if(nThreadID == 1) { qjUI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1]HHe*'Z
} X,&`WPA:S
0,bt^a
\G]K,TG
Utility.log("Thread " + nThreadID + " is over!"); bKTqX[=
bDownOver = true; ]Kof sU_{
//nPos = fileAccessI.write (b,0,nRead); p1C_`f N,
} Q:kwQg:~
catch(Exception e){e.printStackTrace ();} g^qz&;R]
} wE)] ah:
} )7tV*=?Ic8
pz.Y=V\t
coW)_~U|
//打印回应的头信息 ?U=mcdqd
public void logResponseHead(HttpURLConnection con) PKl]GegP
{ -?[O"D"c
for(int i=1;;i++) <##|311o
{ fi5YMYd1
String header=con.getHeaderFieldKey(i); C+DG+_%V*S
if(header!=null) _xa}B,H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2-QuT"Gkd
Utility.log(header+" : "+con.getHeaderField(header)); Fka1]|j9
else XC :;Rq'j
break; d~w}NK[(
} hkkF1 h
} NJ.rv
,"x23=]
Pv^(Q]
public void splitterStop() <yis
{ 4 `j,&=
bStop = true; ys:1Z\$P
} 4F}g(
-/@|2!d
MX"A@p~H
} cb\jrbj6
^- u[q- !
5`(((_Um+
/* +oE7~64LL
**FileAccess.java -bv>iIC
*//文件访问(定位，写) Z83q-
package NetFox; [c,|Lw4
import java.io.*; K-N]h
K(%dcUGDK>
#9URVq,
public class FileAccessI implements Serializable{ w:~nw;.T
6 Xzk;p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zv8aV2?D
RandomAccessFile oSavedFile; r))$XM
long nPos; 6-)7:9y
}IxY(`:qs
7}.#Z
public FileAccessI() throws IOException >1#DPU(g
{ lCM6T;2ID
this("",0); 9O(i+fM
} M!;`(_2
W;xW: -
SSl8
public FileAccessI(String sName,long nPos) throws IOException ]2hF!{wc
{ RTdD]pE8Q
oSavedFile = new RandomAccessFile(sName,"rw"); 2hjre3"?
this.nPos = nPos; (OM?aW
oSavedFile.seek(nPos); 'w>uFg1.
} DLwC5Iir
<~IH`
hNu>s
public synchronized int write(byte[] b,int nStart,int nLen) Co{MIuL
{ EuR!yD
int n = -1; 1puEP*P
try{ ;oN{I@}k
oSavedFile.write(b,nStart,nLen); U89]?^|bb
n = nLen; :F!dTD$
} EM>c%BH<N
catch(IOException e) eONeWY9
{ .y/NudD
e.printStackTrace (); rCnV5Yb0O
} d/ 'A\"o+
rahHJp.Ws
.{'Uvn
return n; Im0+`9Jw
} a'*5PaXU@/
l<0[ K(
C,sD?PcSi+
} 2n-Tpay0
wiK@o$S-
mh!N^[=n
/* G#9o?
**SiteInfoBean.java }J'5EAp
*/ 89:?.'
package NetFox; mVc'%cPaw
{2'74
j. ks UJ
public class SiteInfoBean { ims=-1,
&vJ(P!2f<
fl5UY$a2-
private String sSiteURL; //Site's URL YW4bm
private String sFilePath; //Saved File's Path _{2Fx[m%
private String sFileName; //Saved File's Name 0`g}(}'L
private int nSplitter; //Count of Splited Downloading File T@d_t
4 _c:Vl
Se;?j-
public SiteInfoBean() e"v[)b++Y
{//nSplitter的缺省值为5 5'{qEZs^QU
//default value of nSplitter is 5 :*F3
this("","","",5); PpJE|[]
} $BR=IYby
%%-U.
R%]9y]HQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7YQK@lS
{ fY,@2VxyfA
sSiteURL= sURL; OI]K_ m3
sFilePath = sPath; LS2ek*FJO
sFileName = sName; @^XkU(m
this.nSplitter = nSpiltter; R&x7Iq:=D
]P}K3tN%]
&bS"N)je
} @gu77^='
}jyS\drJ
xsY>{/C
public String getSSiteURL() dEAAm=K,<
{ mvL0F%\.\
return sSiteURL; =yhn8t7@]
} N,sqrk]
5 vu_D^Q
[#P`_hx
public void setSSiteURL(String value) =?`y(k4a
{ Nak'g/uP>
sSiteURL = value; DO1N`7@o
} ^NnU gj
nY"rqILX?
c=jI.=mi3
public String getSFilePath() QU,TAO
{ t7*H8
return sFilePath; Hq"<vp
} _A~~L6C
v,!Y=8~9
s:m<(8WRw
public void setSFilePath(String value) @6i8RmOu}
{ &=6cz$]z
sFilePath = value; UVoLHd
} kb}]sj
2XecP'+m
#by9D&QP]
public String getSFileName() jt10gVC
{ ^b `>/>
return sFileName; ZimMjZ%4
} 13>3R+o
e2Kpx8kWj
(&Tb,H)=
public void setSFileName(String value) :zn ?<(sQ
{ %9-#`
sFileName = value; @cTZ`bg
} .^N#|hp^
8)q]^
yZ(Nv $[5
public int getNSplitter() +N(YR3
{ i6g[E4nk
return nSplitter; 3Ld ;zW
} +{Vwz
I$6 f.W
:9rhv{6Wp
public void setNSplitter(int nCount) ubN"(F:!-S
{ SU#P.y18%
nSplitter = nCount; < jocfTBk
} .^`a6>EQ)|
} ,d [b"]Zy
I}G}+0geV
/YugQ.>| l
/* }Cq9{0by?a
**Utility.java :'=~/GR
*/ @<w9fzi
package NetFox; vA7jZw
A2O_pbQti
"TH-A6v1
public class Utility { O"s`-OM;n
^* /v,+01f
ZNH*[[Pf
public Utility() GT\s!D;<
{ 3RH#e1Y
f{ 4G
v[yTk[zd0
} ^p-e
U0bEB
//线程睡眠 'B<qG<>
public static void sleep(int nSecond) m5;[,He
{ {@K2WB
try{ xMfv&q=k@
Thread.sleep(nSecond); b=QGbFf
} ";Ig%]
catch(Exception e) #ZnX6=;X
{ xV 1Z&l
e.printStackTrace (); )Fr;'JYC1S
} ^B6i6]Pd=9
} \|>`z,;
a^}P_hg}-
//日志 V8U`%/`N
public static void log(String sMsg) A*;^F]~'
{ g;Sg 2
System.err.println(sMsg); )6R#k8'ERr
} !9<RWNKV)Y
=!P?/
Iv|WeSL.
public static void log(int sMsg) UG?C=Tf
{ 5@Lxbe( q
System.err.println(sMsg); 0)Um W{
} VU0tyj$
} J)yy}[Fx
lbuW*)
=UKR<@QrK
/* .gkPG'm[
**TestMethod.java AoOG[to7
*/ _kY[8e5
package NetFox; dV=5_wXZ$
6r-n6#=
3w:Z4]J
public class TestMethod { jUR#
Z2j*%/
xjbyI_D
public TestMethod() llG#nDe
{ ///xx/weblogic60b2_win.exe dVGUhXN6
try{ *=If1qZs
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T[[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >dm._*M
SiteFileFetch fileFetch = new SiteFileFetch(bean); <VxpMF
fileFetch.start(); MJ/%$
} _NqT8C4C
catch(Exception e){e.printStackTrace ();} AW;)_|xM
F#bo4'&>@
68GGS`&
} dUtIAh-j
-Tkd@
Y&!]I84]
public static void main(String[] args) @]"9EW 0
{ lgqL)^8A
new TestMethod(); j}.J$RtW1f
} `8.32@rUB.
} 42LXL*-4
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