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)); #Kn7 xn[
} bmT J
for(int i=0;i<nEndPos.length-1;i++) mO> [kb"V'
{ IwWo-WN7.
nEndPos = nStartPos[i+1]; /_jApZz
} 9h*$P:S;1v
nEndPos[nEndPos.length-1] = nFileLength; z:<(b
} ?]h+En5z8
} 2$1rS}}
Ej.D!@
QW6k!ms$
//启动子线程 jN5Sc0|b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wJ IJPYTK
for(int i=0;i<nStartPos.length;i++) WYaDN:kZf
{ _}JygOew
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rRC3^X`u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X]y3~|K
nStartPos,nEndPos,i); rM>&!?y+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @X\nY</E#M
fileSplitterFetch.start(); g`J? 2 _]
} "OK(<x]3;>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JZP2NB_xt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -*yj[?6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Iun!rv
nEndPos = " + nFileLength); ap;UxWqx
// fileSplitterFetch[nPos.length-1].start(); +[~\\X
8^< -;
uc7Y8iO
//等待子线程结束 6;(Slkv
//int count = 0; B8a!"AQ~5
//是否结束while循环 2M1yw "
boolean breakWhile = false; !L3Bvb;Q
Y|B/(
|'KNR]: N
while(!bStop) ?pQ, 5+8
{ }T(|\ X
write_nPos(); 70KXBu<6
Utility.sleep(500); {v]>sn;P1
breakWhile = true; >O\-\L
(!Ml2
P<2yCovn`
for(int i=0;i<nStartPos.length;i++) xsAF<:S\
{ r-Dcc;+=Q
if(!fileSplitterFetch.bDownOver) !uHI5k,f
{ ih~c(&n0
breakWhile = false; -F5U.6~`!
break; ) mv}u~
} lbv, jS
} x!"!oJG^k
if(breakWhile) *FG@Dts^&
break; _BW$?:)9
W:EXL@
gB~SCl54
//count++; ASu9c2s
//if(count>4) Pv/P<i^
// siteStop(); rx^pGVyg
} jq =-Y
AHZ6
Q g"{F},4
System.err.println("文件下载结束！"); W/?D}#e<4
} L<Lu;KnY6
catch(Exception e){e.printStackTrace ();} rxDule3m
} 0U$6TDtmE
X.UIFcK^
d3n TJX
//获得文件长度 gNZ^TeT
public long getFileSize() IFv2S|
{ }#yRaIp
int nFileLength = -1; ;W+.]_$6)T
try{ N8nyTPw
URL url = new URL(siteInfoBean.getSSiteURL()); #Q$4EQB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {[Yv@CpN
httpConnection.setRequestProperty("User-Agent","NetFox"); yY&(?6\{<<
3q1O:b^eo
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int responseCode=httpConnection.getResponseCode(); 7rhpIP2n
if(responseCode>=400) I=3q#^}[
{ 1 1p\ z
processErrorCode(responseCode); `_v-Y`Z
return -2; //-2 represent access is error S?8q.59
} H!45w;,I
,#"AWQ
JBWiTUk
String sHeader; ZFdQZ=.'
w=^*)jZ8
VVe>}
for(int i=1;;i++) F;~ #\X
{ k)4|%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9r8{9h:
//Utility.log(in.readLine()); }xdI{E1 q)
sHeader=httpConnection.getHeaderFieldKey(i); X=.+XP]
if(sHeader!=null) n*O/X
{ G&Cl:CtC
if(sHeader.equals("Content-Length")) C]r$
{ j?&FK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F^Q
break; xH'H! 8
} +Oyt
} Qy3e,9nS
else 4Y)3<=kDG
break; k| jCc
} :+R||qi
} :*oI"U*f
catch(IOException e){e.printStackTrace ();} ,cm2uY
catch(Exception e){e.printStackTrace ();} W)9KYI9u
{) .=G
@9c^{x\4
Utility.log(nFileLength); Ok*:;G@
L g%cVSz/C
WV&BZ:H
return nFileLength; H-rf?R2
} }_gq vgI>p
s]2k@3|e
uvmNQg
//保存下载信息（文件指针位置） +h9CcBd
private void write_nPos() Ak9W8Z}
{ 4ErDGYg}
try{ )FHaJ*&d
output = new DataOutputStream(new FileOutputStream(tmpFile)); _6(zG.Fg
output.writeInt(nStartPos.length); {+r?gJ
for(int i=0;i<nStartPos.length;i++) \|T0@V
{ -l,ib=ne
// output.writeLong(nPos); ,-{j.
output.writeLong(fileSplitterFetch.nStartPos); N.isvDk%
output.writeLong(fileSplitterFetch.nEndPos); I;xTyhUd
} [I^SKvM
output.close(); 9(@bjL465
} 5Y,e}+I>
catch(IOException e){e.printStackTrace ();} F]ALZxwkz
catch(Exception e){e.printStackTrace ();} gVI*`$
} p@Qzg /X
aFC3yMKXh
rgP$\xn-
//读取保存的下载信息（文件指针位置） h]zx7zt-
private void read_nPos() \Xkx`C
{ i3Ffk+ |b
try{ l"cO@.T3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i"-#1vy=
int nCount = input.readInt(); VK NCK
nStartPos = new long[nCount]; U2bb|6j
nEndPos = new long[nCount]; ,3Wa~\/Q
for(int i=0;i<nStartPos.length;i++) h]D=v B
{ :s$9#}hw,
nStartPos = input.readLong(); d-?~O~qD|!
nEndPos = input.readLong(); }U#S*
} Y&j6;2-Z
input.close(); |RpC0I
} Ia(A&Za
catch(IOException e){e.printStackTrace ();} v h%\ " h
catch(Exception e){e.printStackTrace ();} Z4(2&t^
} nrf%/L
=LT({8
/`'50Cj
private void processErrorCode(int nErrorCode) fO:*85%}7
{ FF/MTd}6qG
System.err.println("Error Code : " + nErrorCode); 6?KsH;L9
} $[>wJXj3R
CId`6W
rVN|OLh
//停止文件下载 rSZWmns
public void siteStop() n@%'Nbc>b
{ 8l}|.Q#--
bStop = true; v)pdm\P
for(int i=0;i<nStartPos.length;i++) ae^xuM?7
fileSplitterFetch.splitterStop(); ,O-lDzcw
AOfQqGf
F`ihw[ Wn
} dyx4_!fO
} -9Can4
//负责部分文件的抓取 w6cPd'
**FileSplitterFetch.java $>BP}V33
*/ qt1#P
package NetFox; -jyD!(
Nh+$'6yT%
s0`uSQ2X
import java.io.*; IBuuZ.=j2h
import java.net.*; oZ8SEC"]
=9)ypI-2
=*(d+[_
public class FileSplitterFetch extends Thread { V3`*LU
"Srp/g]a
G!Uq#l>
String sURL; //File URL s/T5aJR
long nStartPos; //File Snippet Start Position =-:o?&64
long nEndPos; //File Snippet End Position E@@quK
int nThreadID; //Thread's ID R4v=i)A~Z
boolean bDownOver = false; //Downing is over 5fLCmLM`
boolean bStop = false; //Stop identical fe Q%L
FileAccessI fileAccessI = null; //File Access interface ]>AW
r`&ofk1K
\{&55>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i 9b^\&&
{ '!Sj]+
this.sURL = sURL; t]vz+VQ
this.nStartPos = nStart; +fwq9I>L
this.nEndPos = nEnd; uj]GBo=
nThreadID = id; u_[Zu8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :J<S-d=
} 7v?Ygtv
2GD%=rP2]
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public void run() x x 'XR'zK
{ gr2zt&Z4
while(nStartPos < nEndPos && !bStop) ,sc>~B@Q
{ iA< EJ
eR}d"F4W
SEuj=Vie#
try{ O/<jt'
URL url = new URL(sURL); V]<dh|x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qv?jo(]
httpConnection.setRequestProperty("User-Agent","NetFox"); =uvv|@Z
String sProperty = "bytes="+nStartPos+"-"; u.arkp
httpConnection.setRequestProperty("RANGE",sProperty); OC[a?#R1
Utility.log(sProperty); HKh)T$IZM
pkT a^I
i@p?.%K{
InputStream input = httpConnection.getInputStream(); tL3(( W"
//logResponseHead(httpConnection); `hfwZ*s
: i(h[0
z;3}GxE-si
byte[] b = new byte[1024]; ~f@;.
int nRead; ']dTW#i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )Q\;N C=4
{ zJV4)
nStartPos += fileAccessI.write(b,0,nRead); ~<$8i}7
//if(nThreadID == 1) Im Tq`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B]hZ4.B1
} 2T|L##C
Fdzd!r1 v
&?9.Y,
Utility.log("Thread " + nThreadID + " is over!"); @9L%`=]b^
bDownOver = true; *$s)p>
//nPos = fileAccessI.write (b,0,nRead); eHjR/MMr_
} [&39Yv.k,7
catch(Exception e){e.printStackTrace ();} `^6}Dn
} p]>bN
} d82IEhZ#
nyDqR#t
INkrG.=u
//打印回应的头信息 l/1uP
public void logResponseHead(HttpURLConnection con) v` B_xEl
{ <oeHZD_OR
for(int i=1;;i++) T@z$g
{ &d*9#?9
String header=con.getHeaderFieldKey(i); k!%HcU%J
if(header!=null) xWlB!r<}Gz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]]]7"a
Utility.log(header+" : "+con.getHeaderField(header)); A]n!d}?
else #{]=>n)j
break; Vxw?"mhP
} *Lufz-[1
} M35}5+
>DV0!'jW
aTPpE9Pa&
public void splitterStop() @ce4sSo
{ 0W>O,%z&P#
bStop = true; k"n#4o:
} hQkmB|];5
";zl6g"
pGOS'.K%t8
} %+'&$
UM#]olh
B(>_.x#kv
/* AUN Tc3
**FileAccess.java F:H76O`8
*//文件访问(定位，写) p@^2.O+
package NetFox; Y /wvn8~C
import java.io.*; X!"y>J
:q= XE$%H
6HEl1FK{@
public class FileAccessI implements Serializable{ ;or> Sh7
f.u{;W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,%:`Ll t]$
RandomAccessFile oSavedFile; -Pvt+I>
long nPos; {=(4
A,iXiDb3pK
w}E?FEe.
public FileAccessI() throws IOException 1]kk
{ a`{'u)@
this("",0); ;1y\!f3#V~
} z,NHH):~
wbpxJtJB
tC&y3!k2jR
public FileAccessI(String sName,long nPos) throws IOException wUSWB{y
{ }M1<a4~
oSavedFile = new RandomAccessFile(sName,"rw"); 7>4t{aRf_8
this.nPos = nPos; ](W#Tj5-
oSavedFile.seek(nPos); Xau.4&\d
} *]EcjK%
A+dY~@*a
)dvOg'it
public synchronized int write(byte[] b,int nStart,int nLen) x~mXtqg
{ %?cPqRHJ ~
int n = -1; "JGaw_o
try{ bhgh ]{
oSavedFile.write(b,nStart,nLen); aRV!0?fS
n = nLen; |g9^]bT
} ]:f1r8<3p
catch(IOException e) Z@*Z@]FC
{ "q%)we
e.printStackTrace (); SnXLjJe
} :_^YEm+A
9V;m;sz
,iHt*SZ,*
return n; SHaZ-d
} y_nh~&
7X.1QSuE
ar{e<&Bny
} >Te{a*`"m:
7eO8cPy
I?:V EN:
/* eFx*lYjA
**SiteInfoBean.java k{;:KW|
*/ 44]ae~@a
package NetFox; zZy>XHR H
M\]E;C'"U
DnTM#i:
public class SiteInfoBean { [C&c;YNp
$X{& KLM[
[R~HhM
private String sSiteURL; //Site's URL ZWFH5#=
private String sFilePath; //Saved File's Path h0gT/x
private String sFileName; //Saved File's Name Z86[sQBg
private int nSplitter; //Count of Splited Downloading File n1LS*-@
%GIla*
}%}eyLm(
public SiteInfoBean() MRa>@Jn??A
{//nSplitter的缺省值为5 x 1_(j
//default value of nSplitter is 5 E^qKkl
this("","","",5); z4<h)hh"k6
} A76=^iw
?,!qh
O=mJ8W@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i44`$ps
{ >,y QG+
sSiteURL= sURL; c[YC}@l%a
sFilePath = sPath; Xak~He
sFileName = sName; {Cd*y6lI
this.nSplitter = nSpiltter; LO2sP"9
</}[x2w?]
.h6h&[TEU
} %AJdtJ@0H
FkS{Z s
i7p3GBXh[
public String getSSiteURL() $;">/"7m
{ WT0U)x( m5
return sSiteURL; b :+ X3
} B>'\g O\2
`aUA_"f
i^W\YLE
public void setSSiteURL(String value) .d*vfE$
{ g,1\Gj%y
sSiteURL = value; _7;#0B
} ru U|
#8(@a Y
ugL$W@
public String getSFilePath() C{,nDa?|
{ d9^h YS{
return sFilePath; `Ffn:=Do
} 8<o(z'&y
mT9TSW}
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public void setSFilePath(String value) $`riB$v
{ ^yfT7050
sFilePath = value; ](O!6_'d
} 0 8U:{LL
7<) .luV
QM$?}>:
public String getSFileName() @U9ov >E
{ Rk'pymap
return sFileName; Xh{EItk~oO
} c-3? D;
+yYz;, \
Lkb?,j5
public void setSFileName(String value) BEY}mR]
{ AKHi$Bk
sFileName = value; s*Fmu7o43
} 2yN~[,L
68D.Li
/1^%32c
public int getNSplitter() [k.<x'#
{ v3[ 2!UXq
return nSplitter; 7N:,F9V<
} [bZXzV(
UrtN3icph
t#d~gBe?V
public void setNSplitter(int nCount) hxv/285B
{ u=4tW:W,
nSplitter = nCount; 9SU;c l
} .qHgQ_%
} !]"T`^5,Y
cLXMq"?C
uYs+xX_
/* }6o` in>M
**Utility.java Mbi)mybM
*/ BO1Mz=q
package NetFox; /6f$%:q
DQE.;0ld
-m-~
public class Utility { {5RM)J1
-f'z_&KI
1|Fukx<@J<
public Utility() (llg!1
{ H*!E*_
3vMfms
`?La
} JWEqy+,Fjw
9_&.G4%V
//线程睡眠 QYg2'`(
public static void sleep(int nSecond) :V >Z|?[*H
{ Q.!D2RZc
try{ f>Ij:b`Z2
Thread.sleep(nSecond); =i `o+H
} oo/#]a
catch(Exception e) aiz_6@Qfz*
{ r% qgLP{v
e.printStackTrace (); []'BrG)!
} Xo'_|-N+
} O>}aK.H
3Hr ZN+D
//日志 tNq~M
public static void log(String sMsg) \# #~Tq
{ 3p")
System.err.println(sMsg); 0dXWy`Mn
} /5SBLp}Sy
mgg/i@(
0*+i~g,Kl@
public static void log(int sMsg) @UX'(W
{ -MeGJX:^I
System.err.println(sMsg); {Z$Aw4a"d
} dMYDB
} 2jaR_``=:
/SjA;c!.
\]GBd~i<
/* j]YS(Y@AY
**TestMethod.java >+&524xc
*/ eAPGy-
package NetFox; JH5ckgdZ
=r#of|`Q
\y{C>!WX4
public class TestMethod { @/7tN3O
va| 1N/&
LG@5Z-
public TestMethod() L%Me wU0TZ
{ ///xx/weblogic60b2_win.exe /wKL"M-%
try{ lorjMS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >DPC}@Wl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {}~7Gi!
SiteFileFetch fileFetch = new SiteFileFetch(bean); {QI"WFdGx
fileFetch.start(); K&\xbT
} <-FAF:6$@@
catch(Exception e){e.printStackTrace ();} r. :LZEr
`!
AYfW}V"
} 7<=xc'*8t
Il,2^54q
Qv|A^%Ub!
public static void main(String[] args) 7$Jb"s
{ +CaPF
new TestMethod(); 0M>+.}e+
} Ic P]EgB
} IyOb0WiEj
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