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)); R&1>\t
} _;}$/
for(int i=0;i<nEndPos.length-1;i++) } W]A`-Jv
{ zFOtOz`9H
nEndPos = nStartPos[i+1]; >s%Db<(P=
} fBX@ MedC
nEndPos[nEndPos.length-1] = nFileLength; %:C6\4
} gLMb,buqC
} WX Fm'5Vr
W~H`{x%Av>
1n8y4k)
//启动子线程 Q`i@['?p
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A^lm0[3q
for(int i=0;i<nStartPos.length;i++) 9>{ml&$
{ wQW`Er3w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #~Xj=M%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;)ay uS sQ
nStartPos,nEndPos,i); H[w';u[%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dpz@T>MS=
fileSplitterFetch.start(); Z +/3rd
} shB3[W{}!)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jl59;.P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S^R dj ]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @ws&W=NQ
nEndPos = " + nFileLength); JQb{?C
// fileSplitterFetch[nPos.length-1].start(); Vu_oxL}
HnPy";{
KyIUz9$
//等待子线程结束 |HAbZd7PG
//int count = 0; U]pE{^\w
//是否结束while循环 gwNZ`_Q
boolean breakWhile = false; >~d'i
5[2kk5,
*~U*:>hS
while(!bStop) P}'B~~9W
{ uznqq}
write_nPos(); }#g]qK
Utility.sleep(500); /y1+aTiJ
breakWhile = true; L%[>z'Zp
@nqM#
[<r.M<3
for(int i=0;i<nStartPos.length;i++) b4:{PD~Mh
{ K1YxF
if(!fileSplitterFetch.bDownOver) jNbVp{%/S}
{ h5P ]`r
breakWhile = false; vo Et\H
break; yIiVhI?X
} 62;xK-U
} nK< v
if(breakWhile) (e_<~+E
break; =~s+<9c]
3LyNi$`f
BN&)5M?Xt6
//count++; nh7_ jEX
//if(count>4) UvMkL
// siteStop(); U8aVI
} /IcGJ&;
Q~.t8g/
~(*tcs]hY
System.err.println("文件下载结束！"); x+~!M:fAc9
} P,zQl;
catch(Exception e){e.printStackTrace ();} /7#MJH5b6
} T!?tyW
XR VZU~ZV
?(zCv9Pg
//获得文件长度 AP z"k?D0
public long getFileSize() tvno3"
{ v?8i;[
int nFileLength = -1; PcbhylKd
try{ +*Wlj8
URL url = new URL(siteInfoBean.getSSiteURL()); lA4-ZQ2Zp[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .~ uKr^%
httpConnection.setRequestProperty("User-Agent","NetFox"); (z;lNl(*C
R68:=E4
W3ms8=z
int responseCode=httpConnection.getResponseCode(); s;Bh69
if(responseCode>=400) 6?lAbW
{ -vm1xp$
processErrorCode(responseCode); E"[p_ALdC
return -2; //-2 represent access is error 4cy,'B
} AEM;ZQU
DXj>u9*%
b IxH0=f
String sHeader; {o^tSEN!-
H9'psv
#B <%
for(int i=1;;i++) -Sh&x
{ 2\&3x}@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s[eSPSFZ
//Utility.log(in.readLine()); Q%~BD@Io
sHeader=httpConnection.getHeaderFieldKey(i); 67/\0mV:~
if(sHeader!=null) xC5Pv">
{ / j "}e_Q
if(sHeader.equals("Content-Length")) [< g9jX5
{ *[i49X&rd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5"G-r._
break; Nk7=[y#z
} u,:hT] ~+
} GL>YJ%
else #:[F=2@,A
break; zC:Pg4=w]
} =mX26l`B
} o=!_.lDF:
catch(IOException e){e.printStackTrace ();} %hmRh~/&
catch(Exception e){e.printStackTrace ();} &=S:I!9;;
`, ]ui*
og8hc~:ro
Utility.log(nFileLength); I*N v|HST
&2.DZ),L
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return nFileLength; IP{$lC
} >h:'Z*9
<7)sS<I
]Ue aXwaU
//保存下载信息（文件指针位置） IDf\!QGx
private void write_nPos() l-nH
{ 9%SC#V'
try{ 569p/?
output = new DataOutputStream(new FileOutputStream(tmpFile)); }&L%c>
output.writeInt(nStartPos.length); ~}{_/8'5
for(int i=0;i<nStartPos.length;i++) PP\ bDEPy
{ -Op^3WWyY
// output.writeLong(nPos); jPo,mz&^
output.writeLong(fileSplitterFetch.nStartPos); zp:QcL"
output.writeLong(fileSplitterFetch.nEndPos); 7*M-?
} tBJ4lb
output.close(); RcJtVOrd
} a {x3FQ
catch(IOException e){e.printStackTrace ();} ?zC{T*a
catch(Exception e){e.printStackTrace ();} SmDNN^GR
} /zXOtaG
nC[aEZ7
/9gn)q2f(
//读取保存的下载信息（文件指针位置） 8PVjNS/
private void read_nPos() \}4*}Lr
{ \`z%5/@f;
try{ 9MO=f^f-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S,5>/'fy0
int nCount = input.readInt(); 2[(~_VJ
nStartPos = new long[nCount]; WK?5`|1l:x
nEndPos = new long[nCount]; 3O-vO=D
for(int i=0;i<nStartPos.length;i++) nql9SQ'\\
{ oR~d<^z(
nStartPos = input.readLong(); j[R.UB3J
nEndPos = input.readLong(); L#'XN H"
} Gt?l 2s
input.close(); g5pFr=NV
} :JX2GRL4
catch(IOException e){e.printStackTrace ();} .vy@uT,
catch(Exception e){e.printStackTrace ();} 8!.V`|@lt
} !x ~s`z
"P|n'Mx
WvArppANo
private void processErrorCode(int nErrorCode) 5oCg&aT
{ cNwHY Z'
System.err.println("Error Code : " + nErrorCode); ~@6l7H6{
} }[lP^Qs
jDQ?b\^
-G/qfd|s/
//停止文件下载 Fx.Ly]L
public void siteStop() Ye$j43b
{ sCt)Yp+8}B
bStop = true; <FU?^*~
for(int i=0;i<nStartPos.length;i++) <)!,$]S
fileSplitterFetch.splitterStop(); <"K*O9nst
z7sDaZL?_
z k}AGw
} >EFWevT{
} p[xGL } +\
//负责部分文件的抓取 |kvH`&s
**FileSplitterFetch.java L~;(M6Jp
*/ rOE: ap|KL
package NetFox; zdU46|!u
AIn/v`JeX
EZjtZMnj
import java.io.*; h/{1(c}
import java.net.*; w< Xwz`O
JttDRNZAU
[PUu9rz#
public class FileSplitterFetch extends Thread { lqMr@ :t
`#l3a
(57!{[J
String sURL; //File URL o<3$|`S&
long nStartPos; //File Snippet Start Position $Z;/Sh
long nEndPos; //File Snippet End Position pw4^E|X
int nThreadID; //Thread's ID itirh"[
boolean bDownOver = false; //Downing is over ,>b>I#{
boolean bStop = false; //Stop identical 1d FuoX
FileAccessI fileAccessI = null; //File Access interface 8 I_
"|1iz2L
7M7Ir\d0lp
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IKPGqoM
{ S:}"gwFM
this.sURL = sURL; &*7KQd
this.nStartPos = nStart; $57b.+2n
this.nEndPos = nEnd; p$|7T31 *
nThreadID = id; eZU9L/w:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -j]k^
} jMTM:~0N
]7K2S{/o{
7`A]X,:
public void run() RQo a
{ <]1,L%
while(nStartPos < nEndPos && !bStop) K6-M.I
{ J=$\-
TE+>|}]R
rqmb<# Z
try{ egG<"e*W}N
URL url = new URL(sURL); :yD>Tn;1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HLwMo&*rA
httpConnection.setRequestProperty("User-Agent","NetFox"); r#4/~a5i~
String sProperty = "bytes="+nStartPos+"-"; lD3nz<p
httpConnection.setRequestProperty("RANGE",sProperty); 37jxl+
Utility.log(sProperty); :p: C
{LF4_9 =
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InputStream input = httpConnection.getInputStream(); 77)WNL/ x
//logResponseHead(httpConnection); RM `qC
$+7uB-KsU
L0!CHP/nRS
byte[] b = new byte[1024]; W!? h2[
int nRead; Qw'905;(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nDC0^&
{ Su2{nNC>
nStartPos += fileAccessI.write(b,0,nRead); -%yrs6
//if(nThreadID == 1) ;50&s .gZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,n8\y9{G
} sNo8o1Hby
<R@,wzK
kc^,V|Nbq6
Utility.log("Thread " + nThreadID + " is over!"); @pYEzizP7
bDownOver = true; iI IXv
//nPos = fileAccessI.write (b,0,nRead); 'v V7@@
} pCh v;
catch(Exception e){e.printStackTrace ();} Wvr{l
} *|dr-e_j
} }Rw,4
kzRJzJquP
I8 :e`L
//打印回应的头信息 s4"OsgP+
public void logResponseHead(HttpURLConnection con) -<6?ISF2
{ @ps(3~?7
for(int i=1;;i++) |sReHt2)d
{ ;cI*"-I:F
String header=con.getHeaderFieldKey(i); \4>,L_O
if(header!=null) =otO@22Np
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I} jgz
Utility.log(header+" : "+con.getHeaderField(header)); 3@gsKtA&H4
else V|_ h[hXE
break; O[C4xq
} ^E.L8
} !o /=,ZIx
Eu`|8# [ W
r!2U#rz
public void splitterStop() w]0@V}}u$o
{ 2aM7zP[Z
bStop = true; |]*3En:
} R2Fjv@Egk
@m#OhERv
=+!l8o&o,
} Fye>H6MU
K] (*l"'U5
K"0IWA
/* ;v:(
**FileAccess.java P"Al*{:J
*//文件访问(定位，写) q#W|fkfx+
package NetFox; {6zNCO
import java.io.*; 5 aA* ~\
hGz_F/
I x%>aee
public class FileAccessI implements Serializable{ (.ir"\k1(
Db,"Gl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -^xbd_'
RandomAccessFile oSavedFile; }xk(aM_
long nPos; 3#>W\_FY*D
oBkhb
sE pI)9
public FileAccessI() throws IOException !ajBZ>Q
{ `5IrV&a
this("",0); vQljxRtW
} nF,F#V8l
T-en|.
^viabkf C
public FileAccessI(String sName,long nPos) throws IOException _p-e)J$7
{ &J>e;X
oSavedFile = new RandomAccessFile(sName,"rw"); N*o{BboK;
this.nPos = nPos; UZyg_G6
oSavedFile.seek(nPos); @AEH?gOX
} LjI`$r.B
X8$i*#D
e73=*~kfR
public synchronized int write(byte[] b,int nStart,int nLen) ^m|@pp
{ l-+=Yk!X
int n = -1; m2j&0z
try{ x}+zhRJ
oSavedFile.write(b,nStart,nLen); fST.p|b7
n = nLen; p0Jr{hM
} %F;BL8d
catch(IOException e) ^+_rv
{ |C[!A
e.printStackTrace (); q!$s<n
} ]vvYPRV76
("9bV8:@B
yQK{ +w
return n; tVAi0`DV
} heVkCM :
"v8p<JfB`
V?uT5.B2
} @+gr/Pul^
J}#gTG( '
?=? _32O
/* $DL}jH^S
**SiteInfoBean.java q[&Kr+)j
*/ _K^Q]V[nZ
package NetFox; YB38K(
TN(Vzs%
$UR:j8C{p$
public class SiteInfoBean { ^_WR) F'K
LR97FG
e4S@ J/D
private String sSiteURL; //Site's URL @Rr=uf G
private String sFilePath; //Saved File's Path 0:$}~T9T
private String sFileName; //Saved File's Name uJw?5kEbv<
private int nSplitter; //Count of Splited Downloading File v(1 [n]y
\P<aK$g
5Gz!Bf@!!
public SiteInfoBean() 2S?7j[@%i`
{//nSplitter的缺省值为5 >,e^}K}C
//default value of nSplitter is 5 }[AaI #
this("","","",5); u<-)C)z
} n{tc{LII/
0#*6:{/^
OQ-) 4Uk}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) , >LJpv
{ +fP.Ewi
sSiteURL= sURL; e^y9Kmd
sFilePath = sPath; 'ygKP6M
sFileName = sName; #Rw!a#CX.
this.nSplitter = nSpiltter; 2u3Kyn
K10G+'H^
h `Lr5)B'
} S!(3-{nC
n'~==2
7he73
public String getSSiteURL() 1m*)MZ)
{ EA"hie7
return sSiteURL; W$4$%r8
} Coi[cfg0
0<,{poMM
mTZ/C#ir(
public void setSSiteURL(String value) 6TP /0o)
{ O$*lPA[
sSiteURL = value; h^Wb<O`S
} /2tA n
[:8\F#KW
EF0v!XW
public String getSFilePath() giakEPl
{ YYWD\Y`8
return sFilePath; k@4N7}
} }y(t')=9
IW~R{ ]6
TM)INo^
public void setSFilePath(String value) 6/UOzV,[
{ `Fd \dn
sFilePath = value; gRLt0&Q~
} qM\ 2f<)
^^a6 (b
.5|[gBK
public String getSFileName() >?$2`I
{ sscbf
return sFileName; 5YY5t^T
} :""HyjY!
'RjEdLrI
Lq(=0U\"P
public void setSFileName(String value) wvv+~K9jq
{ Z"`w>c.
sFileName = value; )lG}B U.
} UG2+Y']
Z/Rp?Jz\j/
DbMVbgz<e
public int getNSplitter() V]H(;+^P
{ .?Eb{W)^br
return nSplitter; ynIe4b
} ]A5F}wV4
ha :l-<a
=pL$*`]?
public void setNSplitter(int nCount) Nq8ON!<<
{ #(^<qr
nSplitter = nCount; |AYii-g
} 4 &bmt
} 7:4c\C0
WVP?Ie8
MBWoPK
/* .p[uIRd`
**Utility.java (\6E.Z#
*/ K9N31'
package NetFox; _^iY;&
*!QmYH5r0
Ip t;NlR
public class Utility { 1eI*.pt
@Jd&[T27Lr
)!8qJQD
public Utility() T`#nn|
{ yYz{*hq
|`T7}U
-.D?Z8e
} v=k+MvX
i}m'#b
//线程睡眠 d{fd5jv;
public static void sleep(int nSecond) lR?y tIY
{ !tq]kKJ3:
try{ &y? |$p\;/
Thread.sleep(nSecond); "6U0 !.ro@
} k4{!h?h
catch(Exception e) dz^HN`AlzC
{ ~XR('}5D
e.printStackTrace (); +`d92Tz
} }a"=K%b<\
} >Na.C(DZ
O=%Ht-kOc
//日志 8a6.77c
public static void log(String sMsg) _7!ZnJrR
{ gC$_yd6m L
System.err.println(sMsg); GCl *x:
} c7CYulm
tddwnpnSw
%R GZu\p
public static void log(int sMsg) i!YfR]"}
{ DuC#tDP
System.err.println(sMsg); :!Ci#[g
} `l45T~`]$
} AZ.QQ*GZ#y
-mO#HZIq
a;[\nCK
/* {IOc'W-C#2
**TestMethod.java b ri[&=
*/ > TYDkEs0
package NetFox; L} R"1O
HzM\<YD
xd{.\!q.
public class TestMethod { i$kB6B#==
WN]k+0#
`)cI^!
public TestMethod() HS|Gz3~
{ ///xx/weblogic60b2_win.exe $~5H-wJ
try{ 1gK|n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q{h,}[U=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !SuflGx,q
SiteFileFetch fileFetch = new SiteFileFetch(bean); h;q&B9
fileFetch.start(); %ddH4Q/p
} n[>hJ6
catch(Exception e){e.printStackTrace ();} zU1D@
> %KEMlKZ
"E+;O,N-
} k -G9'c~
)2c]Z|
/)[-5n{
public static void main(String[] args) Z"c-Ly{vEj
{ P[fy
new TestMethod(); |mMsU,*gB
} R+.4|1p
} k2Cq9kQq
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