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)); 7q%xF#mK=
} ^sVr#T
for(int i=0;i<nEndPos.length-1;i++) i0}f@pCB?X
{ E.N@qMn~
nEndPos = nStartPos[i+1]; X+2uM+
} gwGw
nEndPos[nEndPos.length-1] = nFileLength; &9Kni/
} B6kc9XG
} }INj~d<:
TJ_Wze-lQ
gpw,bV
//启动子线程 %6.WGuO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X aE;i57$l
for(int i=0;i<nStartPos.length;i++) Z".Xroq~
{ .Gt_~x
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6?(yMSKa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P,J+'.@
nStartPos,nEndPos,i); Y_zMj`HE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xovsh\s
fileSplitterFetch.start(); MxgJ+
} zq(4@S-TU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zm!M'|~@7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4`e[gvh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q6'Q-e)
nEndPos = " + nFileLength); !8e;3W
// fileSplitterFetch[nPos.length-1].start(); -e4TqzRr
~pT1,1
}el7@Gv
//等待子线程结束 Xj9\:M-
//int count = 0; a[_IG-l|i4
//是否结束while循环 ${)oi:K@:
boolean breakWhile = false; 5pT8 }?7
4mHk,Dd9,
$\+x7"pI
while(!bStop) +70x0z2
{ !,|-{":
write_nPos(); eo*l^7
Utility.sleep(500); 72CHyl`|l
breakWhile = true; mBeP"GS
t"s$YB>}
n$rgJ
for(int i=0;i<nStartPos.length;i++) Xub*i^(]
{ b:5-0uxjs
if(!fileSplitterFetch.bDownOver) jM}(?^@
{ &\=Tm~
breakWhile = false; U8.V Rn
break; 7`j%5%q
} dVs=*GEl9
} ODEFs?%'
if(breakWhile) ~&aULY?)]
break; 7gcR/HNeF
>0z`H|;
h,?%,GI
//count++; OqWm5(u&S
//if(count>4) *_Vv(H&
// siteStop(); d#OAM;0}5
} R< L =&I
fK6[ p&
"}"/d(
System.err.println("文件下载结束！"); qSGM6kb
} mW$Oi++'d
catch(Exception e){e.printStackTrace ();} :R`e<g~4
} 5 JlgnxRq
mlxtey6H3
Y&1N*@YP
//获得文件长度 '?jsH+j+
public long getFileSize() tI@aRF=p]2
{ XzPOqZ`Nv
int nFileLength = -1; F$-fj "jC
try{ t.+)g-X
URL url = new URL(siteInfoBean.getSSiteURL()); J'ZC5Xr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #UE}JR3g
httpConnection.setRequestProperty("User-Agent","NetFox"); 'ieTt_1.G
!Rc %
cQ]c!G|a4
int responseCode=httpConnection.getResponseCode(); Wco2i m
if(responseCode>=400) *MS$C$HOq
{ r.'xqzF/
processErrorCode(responseCode); @ x .`z
return -2; //-2 represent access is error ;Xf1BG r
} $KQ q~|
YKz#,
9%Tqk"x?
String sHeader; Zs]n0iwM'@
{sf ,(.W
gxhdxSm=2
for(int i=1;;i++) -uxU[E
{ u]Q}jqiq"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +;\w'dBi,
//Utility.log(in.readLine()); }K={HW1>
sHeader=httpConnection.getHeaderFieldKey(i); 'pT13RFD
if(sHeader!=null) b*(K;`9)B
{ 8Ji`wnkXe
if(sHeader.equals("Content-Length")) j^5YFUwsQg
{ [-VK!9pQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $OG){'X
break; v)T# iw[
} B~E">}=!
} @dk-+YxG
else h (q,T$7W
break; %Z4*;VwQ
} 7~FHn'xt
} 4#}aLP
catch(IOException e){e.printStackTrace ();} er5!ne
catch(Exception e){e.printStackTrace ();} HAL\j5i
mI5J]hk
;:_AOb31N
Utility.log(nFileLength); J;NIa[a
2Mk;r*FT
2F>Y{3&
return nFileLength; [|ZFei)r
} 8^^ 1h
!(7m/R
kc0MQ TJU
//保存下载信息（文件指针位置） "9r$*\wOf
private void write_nPos() nShXY6bA
{ pbEWnx_
try{ g<(!>:h
output = new DataOutputStream(new FileOutputStream(tmpFile)); >O<a9wz
output.writeInt(nStartPos.length); l;KrFJ6
for(int i=0;i<nStartPos.length;i++) }A+ncabm
{ "T_9_6tH
// output.writeLong(nPos); a7c`[
output.writeLong(fileSplitterFetch.nStartPos); /='0W3+o*L
output.writeLong(fileSplitterFetch.nEndPos); =3c?W&:
} ZT@=d$Z&t
output.close(); ?IYu"UO<)|
} zzhZ1;\
catch(IOException e){e.printStackTrace ();} u3#+fn_
catch(Exception e){e.printStackTrace ();} 6i-G{)=l
} n<bU'n
"o+?vx-
.n1&Jsey
//读取保存的下载信息（文件指针位置） g=[OH
private void read_nPos() =]]1x_GB
{ *djLf.I@
try{ :`NZD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iphC\*F
int nCount = input.readInt(); ij!d-eM/b
nStartPos = new long[nCount]; '=vZAV`
nEndPos = new long[nCount]; ?5J# yn
for(int i=0;i<nStartPos.length;i++) ]y6{um8"
{ gy%.+!4>v`
nStartPos = input.readLong(); Fy"M 4;7
nEndPos = input.readLong(); Et!J*{s
} &n;*'M
input.close(); z`IW[N7Z
} uDie205
catch(IOException e){e.printStackTrace ();} /M%>M]
catch(Exception e){e.printStackTrace ();} tu<<pR>
} BW7AjtxQ&
{iX#
iq*im$9J
private void processErrorCode(int nErrorCode) x)*Lu">
{ 72d|Jbd
System.err.println("Error Code : " + nErrorCode); ?/OF=C#
} ~*7$aj
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o3dqsQE%
//停止文件下载 )`rD]0ua;
public void siteStop() I4G0!"T+
{ y Ne?a{
bStop = true; 5aizWz
for(int i=0;i<nStartPos.length;i++) T8a' 6otc
fileSplitterFetch.splitterStop(); y<kUGsD
RbL?(
,Q56A#Y\
} r@3-vLI!u
} U}5fjY
//负责部分文件的抓取 V*b/N
**FileSplitterFetch.java Cu8mNB{H
*/ 3~T ~Bs
package NetFox; ekvs3a^
(O{OQk;CF
fr/EkL1Dl
import java.io.*; ?4%H(k5A
import java.net.*; [(@K;6o
R>O_2`c
H[u9C:}9b
public class FileSplitterFetch extends Thread { c'i5,\#X
,fp+nu8,
UqI #F
String sURL; //File URL 4HGTgS
long nStartPos; //File Snippet Start Position i8V\x>9
long nEndPos; //File Snippet End Position HpEd$+Mz
int nThreadID; //Thread's ID L]H'$~xx*
boolean bDownOver = false; //Downing is over g8N"-j&@
boolean bStop = false; //Stop identical ksC_F8Q+
FileAccessI fileAccessI = null; //File Access interface 6p4BsWPx
2.aCo, Kb;
IFTNr2I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 20V~?xs~
{ = g{I`u
this.sURL = sURL; %PYO9:n
this.nStartPos = nStart; $_"u2"p
this.nEndPos = nEnd; Mwnr4$]
nThreadID = id; 0~fjY^(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qUd7O](b=?
} AB'+6QU9k
d$3rcH1
h p|v?3(
public void run() &`I(QY
{ zG#5lzIu,
while(nStartPos < nEndPos && !bStop) F,Q;sq
{ oRCc8&
nZbI}kcm
Y${'
try{ :EV.nD7
URL url = new URL(sURL); $XhMI;h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BuV71/Vb{Q
httpConnection.setRequestProperty("User-Agent","NetFox"); P`lv_oV
String sProperty = "bytes="+nStartPos+"-"; t,7%| {
httpConnection.setRequestProperty("RANGE",sProperty); ww^\_KGu7
Utility.log(sProperty); hN2A%ds*(j
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J=^IS\m
InputStream input = httpConnection.getInputStream(); =:&xdphZ+
//logResponseHead(httpConnection); .J75bX5
G x[ZHpy;
aj`&ca8
byte[] b = new byte[1024]; P~trxp=k
int nRead; rw'+2\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0SL{J*S4[#
{ v8ap"9b
nStartPos += fileAccessI.write(b,0,nRead); S[F06.(1
//if(nThreadID == 1) /Sj~lHh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *DPX4P
} <IZt]P
7.h{"xOx{
2%pED xui
Utility.log("Thread " + nThreadID + " is over!"); n)kbQ]
bDownOver = true; Bu(51wU8
//nPos = fileAccessI.write (b,0,nRead); U=G49~E
} ]j3>=Jb;
catch(Exception e){e.printStackTrace ();} Mh7m2\fLbd
} yiZtG#6K{
} m;dwt1'Zw
>R F|Q
2$Mnwxfk
//打印回应的头信息 >$ZG=&
public void logResponseHead(HttpURLConnection con) oN1D&*
{ l ;:IL\*1I
for(int i=1;;i++) }Z"iW/?"
{ (t-hi8"
String header=con.getHeaderFieldKey(i); f)*"X[)o
if(header!=null) 6YM X7G]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); iqDyE*a
Utility.log(header+" : "+con.getHeaderField(header)); 6HY): M&?
else efQ8jO
break; @)U.Dbm
} 5%Qxx\q
} *2zp>(%
BmX'%5ho
MLWHO$C~T
public void splitterStop() N1~bp?$1
{ y&$n[j
bStop = true; }emUpju<C
} 7_\sx7h{3
z)3TB&;
1q7&WG
} <VxA&bb7c
L"bJ#0m
|owr?tC
/* a4,V(Hlm
**FileAccess.java ]UvB+M]Lv)
*//文件访问(定位，写) u<S`"MR:J
package NetFox; #%E`~&[
import java.io.*; *E/Bfp1LIe
[9">}l
#kC~qux^
public class FileAccessI implements Serializable{ 4eHSAN"$
,sL'T[tuiU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z Ts*Y,
RandomAccessFile oSavedFile; 8Rj5~+5
long nPos; ^@^8iZ
ws0qwv#
r{R-X3s
public FileAccessI() throws IOException P~\rP6 ;
{ MRLiiIrq,5
this("",0); B"GC|}N)v
} ;"MChk
*J-pAN
G8M~}I/)
public FileAccessI(String sName,long nPos) throws IOException 3:WqUb\QK
{ %OBW/Ti
oSavedFile = new RandomAccessFile(sName,"rw"); =<n ]T;
this.nPos = nPos; V+`kB3GV
oSavedFile.seek(nPos); gRY#pRT6d
} << 6GE
Cf[tNq
roS" q~GS,
public synchronized int write(byte[] b,int nStart,int nLen) c]9gf\WW
{ Zy(i_B-b
int n = -1; V"#0\|]m
try{ =7Ud-5c
oSavedFile.write(b,nStart,nLen); gnp.!-
n = nLen; t=P+m
} qd0G sr}j
catch(IOException e) /!H24[tnk1
{ y[ dBmTY
e.printStackTrace (); Orq/38:4G
} u nv:sV#b
JG!B3^qB
_BewaI;w
return n; 1ubu~6
} SP%X@~d
#*.!J zOg
^OY$ W
} }WsPuo
b-&rMML
iE'_x$i
/* lju5+0BSb
**SiteInfoBean.java 2y!n c%
*/ m^ xTV-#l@
package NetFox; e)e(f"t6Q
wC{sP"D
TZgtu+&
public class SiteInfoBean { E^-c,4'F
|P5dv>tb F
Oa/^A-'Q
private String sSiteURL; //Site's URL +p\E%<uQ
private String sFilePath; //Saved File's Path Wg}KQ6 6
private String sFileName; //Saved File's Name >|SIqB<%:
private int nSplitter; //Count of Splited Downloading File -m`|Sq
d8wGXNd7B
8>C4w 5kF
public SiteInfoBean() H9T~7e+
{//nSplitter的缺省值为5 v^&HZk=(
//default value of nSplitter is 5 #ZZe*B!s_
this("","","",5); 'Dfs&sm
} p\[!=ZXFr\
FF8jW1
\m7\}Nbz0/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Wet0qt]
{ ;#Po}8Y=
sSiteURL= sURL; ?T/4 =
sFilePath = sPath; k4sV6f
sFileName = sName; ^2'Y=g>
this.nSplitter = nSpiltter; <f7 O3 >
.BPd06y
&kb~N-
} gvc@q`_]
$oW=N
*B&P[n
public String getSSiteURL() 'dj3y/ k%
{ J`5VE$2M
return sSiteURL; 4u5j 7`O
} ]O|>nTa
0/QDfA?
oRbWqN`F.
public void setSSiteURL(String value) g]f<k2
{ 29:2Xu i
sSiteURL = value; sPK]:iC
} |Y"XxM9
RC7F/|w.z
Xq1#rK(
public String getSFilePath() 5]i#l3")
{ !>Nlp,r&~
return sFilePath; j}Tv/O,f
} @*hv|zjs
j)@W1I]2#
Ny"9!3V
public void setSFilePath(String value) AON |b\?
{ ~?NCmU=3
sFilePath = value; 8ve-g\C8 H
} /o4_rzR?
UA.Tp[u
s~,!E
public String getSFileName() s$(%]~P
{ yD<#Q\,
return sFileName; t3$cX_
} ytj});,>
qBk[Afjgz
l i<9nMZ<
public void setSFileName(String value) cs2-jbRn
{ 72|gzm
sFileName = value; _L8&.=4]i
} oN}\bK
:awa
}e7/F[c.U
public int getNSplitter() w(HVC
{ N)(m^M(~0
return nSplitter; p7+{xXf
} 1 k!gR
W<<G 'Km
6`9QGi,)
public void setNSplitter(int nCount) pRfKlTU\
{ UusAsezm:
nSplitter = nCount; VsA_x
} (B\Kb4m
} -F`gRAr-
`_yksh3zL4
Q8HNST($?
/* di_N}x*
**Utility.java j&[lDlI_
*/ ~/4j&IG
package NetFox; Fz8& Jn!
CMC p7-v
!T`g\za/
public class Utility { h(2{+Y+
.dzw5R&
pe[huYE
public Utility() wOUCe#P|r
{ heF'7ezv#
}Bh\N5G%
'1!%yKc0
} S%p,.0_
:SFf}
//线程睡眠 x^3K=l;N
public static void sleep(int nSecond) }f> 81[^
{ aQhT*OT{Q
try{ <mLU-'c@
Thread.sleep(nSecond); v-$X1s
} !6.LSY,E
catch(Exception e) bjUe+#BL
{ "7alpjwb
e.printStackTrace (); 7<jr0)
} &}gH!5L m
} fk^DkV^<
L%7WHtU*#
//日志 #\~m}O,
public static void log(String sMsg) {w>ofyqfp&
{ CNiJuj`
System.err.println(sMsg); 5'Mw{`
} U&kdR+dB
Mn\L55?E(
sC.cMZe
public static void log(int sMsg) ygm=q^bV]s
{ -}qay@cDt
System.err.println(sMsg); ),;h
} 7B _Wz9y
} 5;{*mJ:F
Xa8_kv_
@)ozgs@e
/* Wbmqf s
**TestMethod.java vO{[P#L}
*/ 1iY?t
package NetFox; Z_<Wr7D
n-9X<t|*?a
k<*1mS8
public class TestMethod { ,J*#Ixe}
a;7gy419<p
blV'-Al
public TestMethod() d#,
{ ///xx/weblogic60b2_win.exe tG,xG&
try{ YcaLc_pUx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _#UhXXD
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z<"\I60Fe
SiteFileFetch fileFetch = new SiteFileFetch(bean); U,/9fzgd
fileFetch.start(); ;hDIoSz
} $>~4RXC
catch(Exception e){e.printStackTrace ();} 9OF(UFgS
(j}Wt8
i#lO{ ]
} t;%MSedn
[Az^i>iH
nRZ T~S4
public static void main(String[] args) Qa16x<Xlm
{ xJzO?a'
new TestMethod(); . =A|
} ">I50#bT
} () HIcu*i
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