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)); ~el#pf~
} wKe^5|Rr
for(int i=0;i<nEndPos.length-1;i++) j[m\;3Sp
{ F}<&@7kF
nEndPos = nStartPos[i+1]; D}px=?
} }\=9l<|
nEndPos[nEndPos.length-1] = nFileLength; !V$nU8p|
} 's@v'u3
} [nn/a?Z4S
?c"No|@+
G{}E~jDi?
//启动子线程 NwD*EuPF:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N+\#k*n?
for(int i=0;i<nStartPos.length;i++) 26>e0hBh&
{ 9z\q_0&i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !Qjpj KRy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), t#MU2b
nStartPos,nEndPos,i); c)#b*k,lw<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B~-VGT2o
fileSplitterFetch.start(); 468LVe?0
} ?RiW:TQ*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kI]i,v#F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5&v'aiWK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tz j]c
nEndPos = " + nFileLength); B@e,3:
// fileSplitterFetch[nPos.length-1].start(); *58<.L|
@jN!j*Y H
|;6FhDW+'
//等待子线程结束 ?0hk~8c
//int count = 0; zN#$eyt
//是否结束while循环 l Vo](#W
boolean breakWhile = false; ]o$Kh$~5
FT/H~|Z>
Dd<gYPC
while(!bStop) idvEE6I@
{ 8\!0yM#yK
write_nPos(); Q/\ <rG4
Utility.sleep(500); IpGq_TU
breakWhile = true; BRG1/f d
%Gl,V5z&
;"!dq)
for(int i=0;i<nStartPos.length;i++) 44f8Hc1g
{ y1cAw
if(!fileSplitterFetch.bDownOver) 6=Kl[U0Y
{ RZjTUMAz4
breakWhile = false; D(Zux8l
break; _D1bR7
} KArf:d
} M ioS
if(breakWhile) )J<Li!3
break; QB#f'X
}h5pM`|1
.^I,C!O#
//count++; ETV|;>v
//if(count>4) )K -@{v^|
// siteStop(); /XEcA5C<
} TGdD7n&Ehh
(NOAHV0H
7~C@x+1S/
System.err.println("文件下载结束！"); .=3Sm%
} K7M7T5<
catch(Exception e){e.printStackTrace ();} ScQJsFE6
} g % q7
ppN96-]^0
!9356) cV
//获得文件长度 6aK'%K
public long getFileSize() :(} {uG
{ }di)4=U9
int nFileLength = -1; RQy|W}d_
try{ ;dRTr *
URL url = new URL(siteInfoBean.getSSiteURL()); ppR~e*rv-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =\J^_g4-l
httpConnection.setRequestProperty("User-Agent","NetFox"); .MhZ=sn
qeQTW@6 F
<'v?WV_
int responseCode=httpConnection.getResponseCode(); h\Op|#gIT
if(responseCode>=400) F:n(yXA
{ &?9p\oY[
processErrorCode(responseCode); *ls}r5k2Y
return -2; //-2 represent access is error &1F)/$,v
} ~YlbS-
{b<p~3%+Hc
9TO
String sHeader; 2Q|Vg*x\U
3VCyq7B^
g4=}].
for(int i=1;;i++) 0jrcXN~
{ #i7!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J*.Nf)i
//Utility.log(in.readLine()); tU!"CX
sHeader=httpConnection.getHeaderFieldKey(i); Dgc[WsCEW
if(sHeader!=null) ``1#^ `
{ P{)&#HXUVb
if(sHeader.equals("Content-Length")) 5f=e JDo=x
{ %~4R)bsJ'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7xVI,\qV
break; bo$xonV@y
} ='pssdB
} M86v
else @_FL,AC&m
break; |5F]y"Nb
} []1VD#
} RA+Y./*h
catch(IOException e){e.printStackTrace ();} CP7Zin1S/w
catch(Exception e){e.printStackTrace ();} AXH4jQw
*;m5^i<,;S
xHJ+!
Utility.log(nFileLength); /6gqpzum4
\hc}xy 0
JR$Dp&]I
return nFileLength; )qn =
} :?RooJ~#
3.Ni%FF`
qX0IHe
//保存下载信息（文件指针位置） er+m:XuV
private void write_nPos() XsQ<yeun
{ cI?dvfU?
try{ =5oFutg`
output = new DataOutputStream(new FileOutputStream(tmpFile)); }dAb}0XK.
output.writeInt(nStartPos.length); Zul]ekv
for(int i=0;i<nStartPos.length;i++) EqUiC*u8{I
{ "%A/bv\u
// output.writeLong(nPos); VaZS_qGe:
output.writeLong(fileSplitterFetch.nStartPos); gpHI)1i'H
output.writeLong(fileSplitterFetch.nEndPos); M_T$\z;,
} 7w@.)@5
output.close(); ^\e:j7@z
} j &,vju
catch(IOException e){e.printStackTrace ();} '#4ya=Ww
catch(Exception e){e.printStackTrace ();} 0"#tK4
} ;T"}dJel#
za<Ja=f9X
pk}*0Y-
//读取保存的下载信息（文件指针位置） T d4/3k
private void read_nPos() KVtnz
{ uTbI\iq
try{ qOZc}J0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _S,2j_R9
int nCount = input.readInt(); \&2GLBKpe
nStartPos = new long[nCount]; feIAgd},
nEndPos = new long[nCount]; <Sm=,Sw
for(int i=0;i<nStartPos.length;i++) f|Z3VS0x
{ iWCN2om
nStartPos = input.readLong(); H3QAIsGS
nEndPos = input.readLong(); .Ky<9h.K
} fT[6Cw5w`
input.close(); gO*cX&
} 'RQZU*8
catch(IOException e){e.printStackTrace ();} &I:X[=;g
catch(Exception e){e.printStackTrace ();} , *e^,|#
} 8BE OE<
RW,ew!Z
<rRmbFH#
private void processErrorCode(int nErrorCode) 15iCJ p
{ vFL3eu#
System.err.println("Error Code : " + nErrorCode); -gIuL
} Toy~\
:n0(gB
/A_</GYs
//停止文件下载 7#MBT-ih
public void siteStop() ]pB0bJAt
{ :&6QKTX
bStop = true; &5(|a"5+G
for(int i=0;i<nStartPos.length;i++) ]AERi] B
fileSplitterFetch.splitterStop(); $w[@L7'(
z+PSx'#}
_f|Au`7m
} DcSL f4A
} C(?>l.QGw
//负责部分文件的抓取 ;)0vxcMB
**FileSplitterFetch.java kQ.atr`?e
*/ EVgn^,
package NetFox; NZ{kjAd3c
L@CN0ezQs
jn]hqTy8
import java.io.*; =bN[TD
import java.net.*; zi-zg Lx
P:(,l,}F8
"SLN8x49(
public class FileSplitterFetch extends Thread { w]tv<U={
Eqp?cKrji
u$t*jw\fHg
String sURL; //File URL LP@Q8{'
long nStartPos; //File Snippet Start Position XXuU@G6Z7$
long nEndPos; //File Snippet End Position v{Zh!mk* L
int nThreadID; //Thread's ID >p\IC
boolean bDownOver = false; //Downing is over 0z#+^
boolean bStop = false; //Stop identical }=s@y"["
FileAccessI fileAccessI = null; //File Access interface &m>`+uVBP
CyzvQfpZr
*r:8=^C7S
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #q==GT7
{ 4mNL;O
this.sURL = sURL; .A\9|sRZ5
this.nStartPos = nStart; T6OIb
this.nEndPos = nEnd; Tud[VS?99
nThreadID = id; .}SW`RPk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 fhMtnh:
} Bq79Ev .-
ptb t
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public void run() j,6dGb
{ q$:T<mFK$
while(nStartPos < nEndPos && !bStop) ORcl=Eo>
{ tq<7BO<6
W>wE8? _,
6/nhz6=
try{ hP3I_I[qF}
URL url = new URL(sURL); 5{,/m"-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zhHQJcQ.
httpConnection.setRequestProperty("User-Agent","NetFox"); W qci51y>#
String sProperty = "bytes="+nStartPos+"-"; )P:TVe9`
httpConnection.setRequestProperty("RANGE",sProperty); u6t.$a!5
Utility.log(sProperty); #96E^%:zL
ecA0z c~
^:{l~~9iKp
InputStream input = httpConnection.getInputStream(); jBI VZ!X
//logResponseHead(httpConnection); w^G<]S{l
}`f%"Z
Pk~P
byte[] b = new byte[1024]; qZKU=HM
int nRead; 'V 1QuSd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ],qG!,V
{ ^YenS6`F
nStartPos += fileAccessI.write(b,0,nRead); FK@rZP
//if(nThreadID == 1) j\@s pbE@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iknBc-TLD
} 9Hlu%R
hd/5*C{s
qIA!m .GC
Utility.log("Thread " + nThreadID + " is over!"); j,EE`g&
bDownOver = true; JY9Hqf
//nPos = fileAccessI.write (b,0,nRead); j#-ZL-N
} -a&wOn-W
catch(Exception e){e.printStackTrace ();} <gf:QX!
} ?v8RY,Q30
} ~}83\LI}
#^!oP$>1
RX?Nv4-
//打印回应的头信息 Zp- Av8
public void logResponseHead(HttpURLConnection con) g 4Vt"2|
{ 1swh7
for(int i=1;;i++) d/Zt}{
{ lNqXx{!k
String header=con.getHeaderFieldKey(i); S3)JEZi
if(header!=null) S U2`H7C*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1tQZyHc42;
Utility.log(header+" : "+con.getHeaderField(header)); #3kR}Amow
else 2}~1poyi>
break; ',m,wp`
} `j_R ?mY
} ,o*b-Cv/
rIW`(IG_
;X|;/@@
public void splitterStop() zr84%_^
{ KW+^9&lA
bStop = true; F4kU) i
} &rcr])jg[
6NJ La|&n
U NQup;#h
} 9XobTi3+'
?D57HCd`n
\m5:~,p=
/* <C# s0UX
**FileAccess.java 1PLKcU
*//文件访问(定位，写) ~z32%k
package NetFox; jqb,^T|j;m
import java.io.*; Zu&trxnNf[
xhg{!w
r-4I{GPb
public class FileAccessI implements Serializable{ 0 I;>du
"9kEqz4a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c?jjY4u
RandomAccessFile oSavedFile; ;PG'em
long nPos; clG3t eC
asPD>jc
\ E[0KvN;O
public FileAccessI() throws IOException Dih~5
{ RM%lhDFY
this("",0); PeTA:MW
} 6Oo'&3@
*J1pxZ^
*DDfdn
public FileAccessI(String sName,long nPos) throws IOException IGu*#>h
{ RD{jYr;
oSavedFile = new RandomAccessFile(sName,"rw"); =k3QymA
this.nPos = nPos; OjrQ[`(E
oSavedFile.seek(nPos); Y<a/(`
} ^6J*yV%
=jg!@H=_i
Y*wbFL6`
public synchronized int write(byte[] b,int nStart,int nLen) i,;Q
{ E%H,Hk^
int n = -1; g6 7*Bs
try{ 'Nfg%)-N
oSavedFile.write(b,nStart,nLen); 1D=My1B
n = nLen; b$rBxe\
} zx=A3I%7 A
catch(IOException e) \f /<#'
{ 6"&&s
e.printStackTrace (); d{ OY
} Z;WqKIM#
G=yQYsC$
Y*w<~m
return n; -pg7>vOq
} P3lNns3
4fP>;9[F
r10)1`[
} mN@0lfk;
:*}tkr4&eh
rp(`V@x3
/* Ix1ec^?f
**SiteInfoBean.java LNg[fF^:
*/ }c&Zv#iO6
package NetFox; $5il]D`
}"q1B
0qR;Z{k
public class SiteInfoBean { W{Nhh3
'-W p|A
]Ms~;MXlx5
private String sSiteURL; //Site's URL ;=B&t@
private String sFilePath; //Saved File's Path v6oZD;;~
private String sFileName; //Saved File's Name Dk]Y\:
private int nSplitter; //Count of Splited Downloading File -#)xeW.d
$2;YJjz(
n-H0cm
public SiteInfoBean() H3`%#wQ0j
{//nSplitter的缺省值为5 J fsCkS
//default value of nSplitter is 5 !H?#~{ W}
this("","","",5); jZm1.{[>
} cC4*4bMm
DPy"FQYZb
nNBxT+3*i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KwpNS(]I
{ atl0#FBd
sSiteURL= sURL; &yVii^
sFilePath = sPath; ;'=!Fv
sFileName = sName; I&>R]DV
this.nSplitter = nSpiltter; y1k""75
#c?\(qjWA
tw*qlbFHv
} )O2^?Q quS
_NqEhf:8
AQ+w%>G6
public String getSSiteURL() YW/YeID
{ 3fM
return sSiteURL; HC!$Z`}Y
} RJBNY;0
H6'xXS
w="I*7c@
public void setSSiteURL(String value) n"_EDb
{ wXNFL9F8
sSiteURL = value; O- r"G
} ~!)_3o
:2?i9F0_
/6L\`\g
public String getSFilePath() ;O{AYF?,N
{ *h-nI=
return sFilePath; W.0dGUi*
} VQqEsnkz
UN,@K9
}Qg9l|
public void setSFilePath(String value) 4P2)fLmc
{ rJ!xzge;G
sFilePath = value; "d.qmM
} ! daXF&q
NGS/lKz
%)q5hB
public String getSFileName() b/O~f8t
{ ;Iv)J|*
return sFileName; 7i6-Hq
} ,ci tzh
JrCm >0g
Fz>J7(Y.j
public void setSFileName(String value) dc%+f
{ Is?0q@
sFileName = value; 6ng . =
} qIO)Z
DSET!F;PG
Kw-E%7gh4c
public int getNSplitter() ^5"s3Qn
{ W@pVP4F0xM
return nSplitter; 2/>AmVM
} ,v)@&1Wh:
.sjM$#V=
z@<`]
public void setNSplitter(int nCount) 0v',+-
{ &XgB-}^:
nSplitter = nCount; ,{:5Z:<|
} Fwho.R-.
} =b !f
5:56l>0
#l:qht
/* r7w&p.?
**Utility.java |\N[EM%.@
*/ 46}/C5
package NetFox; PtmdUHvD
Eiz\Nb
fqvA0"tv
public class Utility { N}\$i&Vi
3go!P])
rq2XFSXn
public Utility() o.Q|%&1
{ E: XzX Fxx
l+YpRx/T\
7nIg3s%
} h}+,]^
J/RUKhs/
//线程睡眠 ^qV*W1|0
public static void sleep(int nSecond) w*Kw#m'U
{ cWh Aj>?_Q
try{ 4[bw/[
Thread.sleep(nSecond); m6'YFpf)V
} "L{;=-e
catch(Exception e) oPre$YT}h
{ R2u[IVZW:-
e.printStackTrace (); T<p>:$vo
} `\O[9.B
} u5T\_0
%2/WyD$U
//日志 D~2,0K
public static void log(String sMsg) ?]$.3azO
{ jd(=? !_
System.err.println(sMsg); !BK^5,4?--
} %&e5i
/Q{Jf+>R>
0jj }jw
public static void log(int sMsg) Hhfqb"2on
{ 80:na7$)#
System.err.println(sMsg); [f- #pew
} 5#WZXhlc}
} =EV8~hMyqh
I9tdr<
qYbod+UX
/* ^#gGA_H
**TestMethod.java \n+`~< i
*/ B>9D@fmzs
package NetFox; 4my8 p Fk
FC vR
H(n_g QAX
public class TestMethod { 7J0PO}N
s g6
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public TestMethod() c3K(mM:
{ ///xx/weblogic60b2_win.exe l^"gpO${K
try{ Kd^ ._
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9J l9\y9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PJkEBdM.
SiteFileFetch fileFetch = new SiteFileFetch(bean); o7hjx hmC
fileFetch.start(); ))306*X\
} sQTW?KA-Te
catch(Exception e){e.printStackTrace ();} NhpGa@[D
n;2W=N?y
&wLI:x5
} 2BRY2EF
V{c n1Af
eQzSWn[
public static void main(String[] args) JX>_imo
{ _gw~A{O
new TestMethod(); _(oJ8h(
} kdgQ -UN$
} 3#5sj >
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