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)); Rww"Z=F
} r+HJ_R,5A
for(int i=0;i<nEndPos.length-1;i++) &X^~%\F:2
{ !+cRtCaA::
nEndPos = nStartPos[i+1]; `xkJ.,#Io
} kTG}>I
nEndPos[nEndPos.length-1] = nFileLength; n<7#?X7
} M`umfw T
} `SWf)1K
+MOUO$;fGt
KhZ'Ic[vw
//启动子线程 K:P gkc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bTKzwNx
for(int i=0;i<nStartPos.length;i++) '<m[
{ 9Dd/g7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }6eWdm!B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n$}c+1
nStartPos,nEndPos,i); P/t$xqAL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A]BD2
fileSplitterFetch.start(); f7XmVCz1
} p`{9kH1me
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $,icKa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [HIg\N$I8C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k+-u4W
nEndPos = " + nFileLength); 6R@ v>}
// fileSplitterFetch[nPos.length-1].start(); G\TyXq_4
dvsOJj/b
e&F,z=XJ}
//等待子线程结束 (XT^<#Ga
//int count = 0; VX&KGG.6
//是否结束while循环 +YhTb
boolean breakWhile = false; O" ['.b
+S|y)W8
$K\\8$Z
while(!bStop) p=9G)VO
{ 1h]Dc(Oc#=
write_nPos(); "xS",6Sy
Utility.sleep(500); wamqeb{u
breakWhile = true; " I`<s<
`-Gs*#(/
Tb}`]Y`X
for(int i=0;i<nStartPos.length;i++) V#w$|B\
{ o?^j1\^
if(!fileSplitterFetch.bDownOver) s<z{(a
{ 4jis\W}%L3
breakWhile = false; if:2sS9r
break; i/oaKpPN
} EEn}Gw
} yBauK-7*c
if(breakWhile) N+!{Bt*
break; {:od=\*R
8!me$k&
D4n~2]
//count++; ]Rnr>_>x;
//if(count>4) Z'WoChjM
// siteStop(); :(A]Bm3
} rN$_(%m_N
rq}ew0&/
_l}&|:
System.err.println("文件下载结束！"); ^N`ar9Db
} tB}&-U|t[~
catch(Exception e){e.printStackTrace ();} y| @[?B
} 49_b)K.tB
InNuK0@
uGc}^a2
//获得文件长度 hRxR2
public long getFileSize() )"A+T&
{ C#>c(-p>RC
int nFileLength = -1; zWB>;Z}
try{ N}VKH5U|
URL url = new URL(siteInfoBean.getSSiteURL()); 3HFsR)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RH6qi{)i!
httpConnection.setRequestProperty("User-Agent","NetFox"); 98Pt&C?-B
a,M7Bbx
<G\q/!@_
int responseCode=httpConnection.getResponseCode(); O)`R)MQ)
if(responseCode>=400) 2@:Go`mg
{ 5"^$3&)
processErrorCode(responseCode); 6/.-V1*O
return -2; //-2 represent access is error ?$pp%
} Bz9!a k~4
8_8R$=V
?J6J#{LRd
String sHeader; Z!~~6Sq
CdatN$/*
&'c1"%*%8>
for(int i=1;;i++) >UZfi u
{ m}Kn!21
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5RI"gf
//Utility.log(in.readLine()); !95ZK.UT
sHeader=httpConnection.getHeaderFieldKey(i); 5R/k -h^`
if(sHeader!=null) ~WehG<p v[
{ vkASp&a
if(sHeader.equals("Content-Length")) !m'lOz
{ 9'\18_w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :)cPc7$8
break; [$;6LFs}
} pDCQ?VW
} <i%.bfQ/-
else +Q}Y?([
break; mcpM<vY/H
} c3Y\XzV3v
} 68+9^
catch(IOException e){e.printStackTrace ();} HKb8z@;%@
catch(Exception e){e.printStackTrace ();} ^6Hfq^ejt
yFH)PQ_
xuv%mjQ
Utility.log(nFileLength); LylB3BM
2"c$#N
a~9U{)@F
return nFileLength; hcWkAR
} 37T<LU
>j|.pi
Zh6bUxr
//保存下载信息（文件指针位置） }tua0{N:z
private void write_nPos() MHpPb{^
{ 1ePZs$
try{ l~!\<, !
output = new DataOutputStream(new FileOutputStream(tmpFile)); liA)|.H
output.writeInt(nStartPos.length); SQ1.jcWW[
for(int i=0;i<nStartPos.length;i++) JC_Y#kN@z
{ tTLD6#
// output.writeLong(nPos); ;Bat!K7W
output.writeLong(fileSplitterFetch.nStartPos); C*,-lk0b@
output.writeLong(fileSplitterFetch.nEndPos); [C,<Q
} K;sH0*
output.close(); cuB~A8H#}
} w\:-lXw
catch(IOException e){e.printStackTrace ();} :0Rd )*k,v
catch(Exception e){e.printStackTrace ();} B=jJ+R
} 0;#%KC,
SirjWYap
8&IsZPq%l
//读取保存的下载信息（文件指针位置） i"_)91RA
private void read_nPos() %r=uS.+hrF
{ |Z0?
try{ J3Qv|w[3Y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Yo/U/dB
int nCount = input.readInt(); X2}\i5{
nStartPos = new long[nCount]; E*:!G
nEndPos = new long[nCount]; 1j`-lD
for(int i=0;i<nStartPos.length;i++) M$B9?N6
{ _*>bf G
nStartPos = input.readLong(); +\fr3@Yc
nEndPos = input.readLong(); E5~HH($b
} t>)iC)^u
input.close(); C\ZL*,%}
} Vl%AN;o
catch(IOException e){e.printStackTrace ();} m.iCGX
catch(Exception e){e.printStackTrace ();} rr>QG<i;G
} o8-BTq8
r`qMif'
w4Qqo(
private void processErrorCode(int nErrorCode) j&6,%s-M`a
{ GvF8S MO[x
System.err.println("Error Code : " + nErrorCode); '_lyoVP
} zH0%; o}
[ >O4hifq
XZEawJ0
//停止文件下载 W2D^%;mw
public void siteStop() /`Yy(?,
{ 5Q#;4
bStop = true; w},' 1
for(int i=0;i<nStartPos.length;i++) DJ_,1F
fileSplitterFetch.splitterStop(); #=V%S 2~
+dX1`%RR[
6}='/d-[
} MUhC6s\F
} m4bfW
//负责部分文件的抓取 h$F;=YS
**FileSplitterFetch.java o@>{kzCx
*/ / *RDy!m
package NetFox; 7g[m,48{
>6*"g{/
}zY)H9J~
import java.io.*; #s$b\"4
import java.net.*; q#:,6HDd
ZF"f.aV8)
WPygmti}Be
public class FileSplitterFetch extends Thread { G~1#kg
P~Q5d&1SO
7-6Z\.-
String sURL; //File URL &$?e D{
long nStartPos; //File Snippet Start Position _CY>45
long nEndPos; //File Snippet End Position >J_{mU
int nThreadID; //Thread's ID O# .^}
boolean bDownOver = false; //Downing is over '%_1eaH
boolean bStop = false; //Stop identical Q/m))!ikMt
FileAccessI fileAccessI = null; //File Access interface 7}OzTup
%_0,z`f
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IT! a)d
{ &I Iw>,,
this.sURL = sURL; 1mhX3
this.nStartPos = nStart; t j&+HC
this.nEndPos = nEnd; :@jhe8'w
nThreadID = id; SweaERl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LTj;e[
} L+LxS|S+M
b Gq0k&
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public void run() pJrc\`D
{ z~Ph=1O>p
while(nStartPos < nEndPos && !bStop) X0O0Y>"
{ X|K"p(N
!8yw!hA
|7,|-s[R^
try{ no- Lx-x
URL url = new URL(sURL); ,mEFp_a+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %;yDiQ!+
httpConnection.setRequestProperty("User-Agent","NetFox"); 34-QgE
String sProperty = "bytes="+nStartPos+"-"; >8_#L2@
httpConnection.setRequestProperty("RANGE",sProperty); lTJ1]7)
Utility.log(sProperty); o90SXa&l/
Qj5~ lX`W
}ddwL
InputStream input = httpConnection.getInputStream(); xoF]r$sC8
//logResponseHead(httpConnection); -fw0bL%0
h>-JXuN
4r;!b;3
byte[] b = new byte[1024]; }M'h5x
int nRead; q$z#+2u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #gq4%;
{ RBIf6oxdE
nStartPos += fileAccessI.write(b,0,nRead); #u~s,F$De
//if(nThreadID == 1) [/hS5TG|7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (mz5vzyw
} >8Wvz.Nq/
JYL/p9K[I
n)uvN
Utility.log("Thread " + nThreadID + " is over!"); I'2:>44>I6
bDownOver = true; =A={Dpv[>
//nPos = fileAccessI.write (b,0,nRead); )k01K,%#)
} XIh2Y\33ys
catch(Exception e){e.printStackTrace ();} vn|u&}h
} OLUQjvnU
} tRRPNY
@iK=1\-2
cE>K:3n
//打印回应的头信息 %^[45e
public void logResponseHead(HttpURLConnection con) QLH&WF
{ }1]/dCv
for(int i=1;;i++) :bI4HXT3
{ }3:DJ(Y
String header=con.getHeaderFieldKey(i); *#1&IJPI
if(header!=null) >Z?fX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r?Jxl<
Utility.log(header+" : "+con.getHeaderField(header)); kCfSF%W&
else qH!}oPeU'
break; ;ZXP*M9
} tW53&q\=
} `l@[8H%aw
"r @RDw
r/1:!Vu(
public void splitterStop() gS4zX>rqe
{ A`<#}~A
bStop = true; .o91^jt
} mbxJS_P
s<gZB:~
1}#v<b$
} @?iLz7SPk
P7QOlTQI
n={}='
/* \kcJF'JFA0
**FileAccess.java z_R^n#A~r
*//文件访问(定位，写) JL $6Fw;
package NetFox; i3t=4[~oL
import java.io.*; ozH7c_ <
W)JUMW2|
%])-+T
public class FileAccessI implements Serializable{ vF"<r,pg
gP8Fe =]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0fA42*s;
RandomAccessFile oSavedFile; JPfNf3<@My
long nPos; :J]S+tQ)
WsRG>w3"
/_y%b.f^
public FileAccessI() throws IOException *%1:="W*|
{ DfwxPt#
this("",0); 16/+ O$#y
} <_@ K4zV
6} "?eW
2A|^6#XN'
public FileAccessI(String sName,long nPos) throws IOException 0i\ol9,bf
{ "Pi\I9M3
oSavedFile = new RandomAccessFile(sName,"rw"); bcL>S$B
this.nPos = nPos; rt$z&#M
oSavedFile.seek(nPos); pq_DYG]
} ~K%]9
$l-|abLELz
f gI.q
public synchronized int write(byte[] b,int nStart,int nLen) P`6 T;|VDk
{ 75i M_e\
int n = -1; i@e.Uzn
try{ xb\(>7M6Y
oSavedFile.write(b,nStart,nLen); =o;QvOS;
n = nLen; ^-{ 1]G:
} hPr*<2mp
catch(IOException e) zrk/}b0j
{ ^4(CO[|c~
e.printStackTrace (); 6i[\?7O'0
} QT{$2 7;
aGVzg$
"wL~E Si
return n; A[J9v{bD
} 0CS^S1/[B`
2+"=i/8
4 q}1
} C>7Mx{!H
fHvQ9*T
f/Km$#xOr
/* jENarB^As
**SiteInfoBean.java xP*9UXZ4P
*/ wpu]{~Y
package NetFox; 2!>phE
&:=
Gp9>R~$
public class SiteInfoBean { {YZ)IaqZ
C.L5\"%
,{ CgOz+Ul
private String sSiteURL; //Site's URL VOwt2&mZ
private String sFilePath; //Saved File's Path ?2[=llS4
private String sFileName; //Saved File's Name fOiLb.BW
private int nSplitter; //Count of Splited Downloading File k/AcXU%O+
Dntcv|%u
$D5[12X
public SiteInfoBean() Na: M1Uhb
{//nSplitter的缺省值为5 -cyJjLL*
//default value of nSplitter is 5 A>+5~u
this("","","",5); T[xGF/
} RK(uC-l
j>gO]*BX~
ehCc N4V(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) dgd&ymRm :
{ {l{p
sSiteURL= sURL; ?I}jsm1)
sFilePath = sPath; +P|$T:b
sFileName = sName; JfKhYRl
this.nSplitter = nSpiltter; z/ T|
_tL+39 u
acB,u&
} *{W5QEa
I'"*#QOX
RL~|Kr<7J
public String getSSiteURL() @ :Q];rc
{ ;nLQ?eS\
return sSiteURL; ]]o7ej
} i051qpj
vq$%Ug/B
\F,?ptu
public void setSSiteURL(String value) ;1S{xd*^N
{ ]w%7/N0R
sSiteURL = value; c}Jy'F7&f
} V)R-w`
GK/a^[f+'l
o]n5pZ\\W<
public String getSFilePath() ,8o]XFOr
{ R8EDJ2u#
return sFilePath; gv `jeN
} GEA@AD=^f
':[+UUC@
WP32t@
public void setSFilePath(String value) `@ qSDW!b
{ )ty *_@N0
sFilePath = value; +<:p`%
} gb@Rx
rd]HoFE
r!Eo8C
public String getSFileName() ( NjX?^
{ {ZbeF#*"
return sFileName; ~FZLA}
} St|sUtj<r
[lS'GszA
|:!#kA
public void setSFileName(String value) -iBu:WyY$
{ mwbkXy;8
sFileName = value; .^@+$}
} WSDNTfpI
_<;#=l
wVE"nN#
public int getNSplitter() SZG8@ !_}7
{ BOL_kp"
return nSplitter; 3I:DL#f
} %Tsefs?_
FD|R4 V*3
GD[~4G
public void setNSplitter(int nCount) :KX/`
{ XIBw&mWf
nSplitter = nCount; Ea\a:
} W7(OrA!
} U@& <5'
SKLQAE5
m{%_5nW
/* 2:p2u1Q O
**Utility.java =AgY8cF!sl
*/ ,)]ZD H
package NetFox; \`>Y
t T-]Vj.
6ap,XFRMh
public class Utility { 0)ST_2Ci
+Ya-h~7;g#
C&e
public Utility() %Pa-fee
{ Crpkq/M
::TUSz2/2
bL0+v@(r
} DMf^>{[
d_5h6Cz4
//线程睡眠 ~d{E>J77j
public static void sleep(int nSecond) !\awT
{ t"0~2R6i
try{ a$aI%
Thread.sleep(nSecond); c |C12b[
} KOF!a
catch(Exception e) VKik8)/.
{ r.K4<ly-N
e.printStackTrace (); Fof_xv9
} /E]4N=T
} ew`R=<mZ,7
"A/kL@-C
//日志 |0qk
public static void log(String sMsg) 0-|1}/{4
{ H>DJ-lG(
System.err.println(sMsg); N_gjOE`x5
} (Nik(Oyj"
40g&zU-
l}O`cC
public static void log(int sMsg) yaX,s4p
{ RhQOl9
System.err.println(sMsg); aY {.
} m
} 1H[lf B
|23 }~c,
<K97eAcW
/* p:4vjh=1h
**TestMethod.java W_DO8nX
*/ v>nJy~O]
package NetFox; 10[~ki-1;
$C[YqZO
}`_2fJ6
public class TestMethod { "lz!'~im
yTDoS|B+)
U{O\
public TestMethod() 4a3f!G$
{ ///xx/weblogic60b2_win.exe M1ayAXO
try{ sdO;vp^:b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V_ ]4UE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z].>U!7W
SiteFileFetch fileFetch = new SiteFileFetch(bean); T8KhmO
fileFetch.start(); -8pHjry'q
} v5 9>
catch(Exception e){e.printStackTrace ();} = Oq;
\2+xMv)8
9J%>2AA
} uq%RZF z(v
V)a6H^l
71A{"
public static void main(String[] args) \7C >4
{ ?%LD1 <ya
new TestMethod(); J]~fv9~P
} C$(t`G
} 6*LU+U=`
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