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)); K{%}kUj>
} ]s?BwLU6
for(int i=0;i<nEndPos.length-1;i++) H-K,Q%;C@
{ ;H9d.D8
nEndPos = nStartPos[i+1]; :<YcV#!P
} @kK${
nEndPos[nEndPos.length-1] = nFileLength; vd c k
} k-@CcrepF
} TPZZln'3
/d ?)
rDX_$,3L
//启动子线程 Z$ {I4a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N 3i,_
for(int i=0;i<nStartPos.length;i++) TL ;2,@H`
{ +/*g?Vt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4&~ft
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0K <@?cI
nStartPos,nEndPos,i); ?"]fGp6y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jtnuo]{R
fileSplitterFetch.start(); Uc/MPCqZ
} 'j6PL;~c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qsk8#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *y9 iuJ}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9&q<6TZz
nEndPos = " + nFileLength); O,>1GKw"\
// fileSplitterFetch[nPos.length-1].start(); ja3wXz$2
{}H5%W
kz\ D-b
//等待子线程结束 j(F&*aH78
//int count = 0; Yv\.QrxPm
//是否结束while循环 awQf$
boolean breakWhile = false; .?UK`O2Q
vE0Ty9OH"]
m=b~Wf39
while(!bStop) lG;RfDI-
{ X3vTyIsn
write_nPos(); uvz}qH@j/Q
Utility.sleep(500); V'sp6:3*\
breakWhile = true; ??5qR8n.
g^OU+7o
8aQ\Yx
for(int i=0;i<nStartPos.length;i++) B<i)je!
{ 8 !]$ljg
if(!fileSplitterFetch.bDownOver) \Q7Nz2X
{ R,-y
breakWhile = false; p:U9#(v)
break; =PWh,lWS
} Z;M]^?
} /.l8Jb4
if(breakWhile) O'{UAb+-
break; ?}\aG3_4
|q"WJQ
c+c3C8s*8
//count++; <GC<uB |p
//if(count>4) Wu(6FQ`H
// siteStop(); -&I%=0q
} w-*$gk]
^UHt1[
*9M 5'
System.err.println("文件下载结束！"); 'L4@|c~x
} mO;X>~K
catch(Exception e){e.printStackTrace ();} t<mT=(zt*
} t$^1A1Ef
Z[<rz6%cB
,rVm81-2
//获得文件长度 gq~>S1
public long getFileSize() Sr Z\]
{ iK8aj)%Q@
int nFileLength = -1; "v@$CR9<T
try{ Z(Fsk4,
URL url = new URL(siteInfoBean.getSSiteURL()); ~n9BN'@x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L!s/0kBg
httpConnection.setRequestProperty("User-Agent","NetFox"); ,R]hNjs-{
0i/l2&x*k]
??0C"8:[
int responseCode=httpConnection.getResponseCode(); vY0C(jK
if(responseCode>=400) mJe;BU"y]
{ /{Ksi+q
processErrorCode(responseCode); .q$HL t
return -2; //-2 represent access is error *ci,;-*C
} w|!>>W6J
)_N|r$i\
(yIl]ZN*
String sHeader; $o"Szy
W}p>jP}
1^ZQXUzl%i
for(int i=1;;i++) (oO*|\9u
{ :c3}J<Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Nv}'"V>
//Utility.log(in.readLine()); ^vmT=f;TM
sHeader=httpConnection.getHeaderFieldKey(i); F!OVx<
if(sHeader!=null) S'm&Ll2i@
{ G,I[zhX\
if(sHeader.equals("Content-Length")) vJ9Uw
{ LDqq'}qK6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); m|!R/,>S4
break; &m2FEQLj
} }mQ7N&cC
} P6V_cw$
else 8wz%e(
break; t:NTk(
} vn<z\wVbf
} g]?&qF}
catch(IOException e){e.printStackTrace ();} {E`[`Kf
catch(Exception e){e.printStackTrace ();} m?bd6'&FR
YSERQo
#12
Utility.log(nFileLength); nTxeV%
*X- 6]C
5W_u|z+/g
return nFileLength; S\=j; Uem
} jq#gFt*
PhL}V|W>
Q`k=VSUk
//保存下载信息（文件指针位置） ep`WYR|B
private void write_nPos() OCmF/B_
{ 6' }oo'#~
try{ .v;$sst5y
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1H sfCky{
output.writeInt(nStartPos.length); ?RL[#d+y
for(int i=0;i<nStartPos.length;i++) )cOw9&#s
{ %&m/e?@%I
// output.writeLong(nPos); A_3V1<J`]
output.writeLong(fileSplitterFetch.nStartPos); h.CbOI%Q
output.writeLong(fileSplitterFetch.nEndPos); Wm>[5h%>
} @b[{.mU
output.close(); \|9@*]6:
} pJ35M
catch(IOException e){e.printStackTrace ();} }pOL[$L
catch(Exception e){e.printStackTrace ();} W FVx7
} ;mH O#
<>JN&#3?
l",JN.w
//读取保存的下载信息（文件指针位置） *6D0>F
private void read_nPos() _aa3;kT_
{ J60XUxf
try{ 5u +U^D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &|>CW:)&1"
int nCount = input.readInt(); 3aIP^I1
nStartPos = new long[nCount]; i}teY{pyc
nEndPos = new long[nCount]; s;V~dxAiv
for(int i=0;i<nStartPos.length;i++) ( HCB\!g
{ qW*JB4`?a
nStartPos = input.readLong(); BoQLjS{kN
nEndPos = input.readLong(); :xOne<@
} I\djZG$s;N
input.close(); 1OB,UU"S$
} )yvI {
catch(IOException e){e.printStackTrace ();} c'M#va
catch(Exception e){e.printStackTrace ();} k L\;90
} u!I Es
M^^5JNY
(IdXJvKU!
private void processErrorCode(int nErrorCode) f P'qUN
{ #'5|$ug[
System.err.println("Error Code : " + nErrorCode); ):"Z7~j=
} al>^}:
RsV<4$
y+b4sFf
//停止文件下载 _BGw)Z 6
public void siteStop() `x=W)o }
{ $="t7C9S
bStop = true; 2R9AYI
for(int i=0;i<nStartPos.length;i++) 533n z8&9@
fileSplitterFetch.splitterStop(); E"d\N-I
_<tWy+.
:|cC7,S
} X(sHFVU+
} Hy4c{Ij
//负责部分文件的抓取 kA3nhBH
**FileSplitterFetch.java 6*yt^[W
*/ Qtj.@CGB
package NetFox; eeKErpj8A
zN}1Qh
A+3,y<j\
import java.io.*; 7&oT}Z
import java.net.*; 'Cw&9cL9w
( R2432R}J
UjCQ W:[
public class FileSplitterFetch extends Thread { 6)<g%bH!
(-k`|X"
1, 5"sQ$
String sURL; //File URL Vl=!^T}l+
long nStartPos; //File Snippet Start Position b4NUx)%ln
long nEndPos; //File Snippet End Position b(^gv
int nThreadID; //Thread's ID `PML4P[
boolean bDownOver = false; //Downing is over }dnO7K
boolean bStop = false; //Stop identical I+nKaN+8i
FileAccessI fileAccessI = null; //File Access interface G@s]HJ:
+/!kL0[v
+; /]'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \:>GF-Z(
{ `qP <S
this.sURL = sURL; FR%9Qb7
this.nStartPos = nStart; zadn`B#2
this.nEndPos = nEnd; Md!L@gX6<
nThreadID = id; b| e7mis@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yGGQ;!/
} jUny&Alj
&T7|f!y
=Xwr*FTr
public void run() DH7B4P
{ b*C\0D
while(nStartPos < nEndPos && !bStop) _i@{:v
{ ;F>$\"aG
%x$1g)
"J51\8G@@
try{ ly,3,ok
URL url = new URL(sURL); UO3QwZ4j;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +Fn^@/?yC
httpConnection.setRequestProperty("User-Agent","NetFox"); "9mVBa|Q
String sProperty = "bytes="+nStartPos+"-"; DeqTr:
httpConnection.setRequestProperty("RANGE",sProperty); 8sMDe'
Utility.log(sProperty); +7yirp~`K
y2"PKBK\_
Xx.4K>j+j
InputStream input = httpConnection.getInputStream(); :exgdm;N
//logResponseHead(httpConnection); c?@WNv
+rT%C&ze
&yu3nA:7D
byte[] b = new byte[1024]; lr>:S
int nRead; Xz/5Wis4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z^@.b
{ IZr~h9
nStartPos += fileAccessI.write(b,0,nRead); [VvTR#^
//if(nThreadID == 1) $e(]L(o;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jg2UX
} cvoE4&m!
T6T3:DG_B
px|y_.DB2x
Utility.log("Thread " + nThreadID + " is over!"); PKDzIA~T
bDownOver = true; x#wkODLqi
//nPos = fileAccessI.write (b,0,nRead); m8Wv46%
} ~|W0+&):
catch(Exception e){e.printStackTrace ();} $!~R'N c
} $f++n5I
} _e2=BE`W)
OR{<)L
qG=?+em
//打印回应的头信息 977%9z<h
public void logResponseHead(HttpURLConnection con) +Ce[OG.
{ M84{u!>[
for(int i=1;;i++) =bn(9Gm!J
{ .9":Ljs(L
String header=con.getHeaderFieldKey(i); 6Z5X?B
if(header!=null) Ino$N|G[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "6[a%f#Q
Utility.log(header+" : "+con.getHeaderField(header)); {zTo[i
else B8XW+U
break; A`|Z2
} s& INcjC
} X#625h
MCPVql`+`q
}]dK26pX
public void splitterStop() ,r=9$i_
{ U8f!yXF'
bStop = true; +XaRwcLC.
} ySfot`LQ
&m=GkK
dA)JR"r2
} NNKI+!vg
(8Q0?SZN
O9+Dd%_KS#
/* h8nJt>h
**FileAccess.java *wH.]$
*//文件访问(定位，写) I:~KF/q
package NetFox; goE \C
import java.io.*; vbo|q[z
3YKJN4
kIC$ai6.
public class FileAccessI implements Serializable{ O\3 Lx
|4$.mb.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]lX`[HX7
RandomAccessFile oSavedFile; xz$-_NWW
long nPos; C:*=tD1
%anY'GK
fU6O:-
public FileAccessI() throws IOException {Xw6]d
{ {D6p?TL+
this("",0); TFfV?rBI
} cO8':P5Q
:.k1="H~@
{V8yJ{.G
public FileAccessI(String sName,long nPos) throws IOException 3"*tP+H
{ fbTq?4&Q
oSavedFile = new RandomAccessFile(sName,"rw"); )S:,q3gxJ
this.nPos = nPos; eD(;Wn
oSavedFile.seek(nPos); 65%WjO
} 9\QeH'A
wZ(H[be
(G>S`B
public synchronized int write(byte[] b,int nStart,int nLen) s6U$]9 `
{ lQ8h-Tz
int n = -1; h_( #U)z_3
try{ Io(*_3V)B
oSavedFile.write(b,nStart,nLen); 2`|gnVw
n = nLen; H%nA"-
} D]?eRO9'
catch(IOException e) f3>L/9[[<P
{ y;\m1o2
e.printStackTrace (); 1BjMVMH
} Q.U wtH
'3p7ee&
Jw4#u5$$Z
return n; ^vj}
} s~z~9#G(6
}&*wJ]j`L
*(,zPn,
} { R`"Nk
'bd|Oww1u
s|`ZV^R
/* yd}1Mx
**SiteInfoBean.java ?rJe"TOIy
*/ 8opd0'SNaB
package NetFox; rWP -Rm
18HmS>Qo
A2 r\=for
public class SiteInfoBean { eT'Z;ZO
*=2sXH1j
Uhw:XV@m
private String sSiteURL; //Site's URL f`gs/R
private String sFilePath; //Saved File's Path qk{+Y
private String sFileName; //Saved File's Name @W1F4HYds
private int nSplitter; //Count of Splited Downloading File 2Y7u M;8
N|rB~
baO'FyCs9&
public SiteInfoBean() 9cnLf#
{//nSplitter的缺省值为5 0Ym_l?]m[
//default value of nSplitter is 5 G%HuB5:u
this("","","",5); ^H(,^cVN
} ^vY[d]R _\
+%~/~1
q:/3uC7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^[6S]Ft(
{ SWLt5dV
sSiteURL= sURL; zR!p-7_w
sFilePath = sPath; jU9\BYUg
sFileName = sName; )Jaq5OMA/
this.nSplitter = nSpiltter; iLbf:DXK(
n/6qc3\5i
|>~pA}
} }0oVIr
tW -f_0a.
QFNw2:)
public String getSSiteURL() [["az'Lrk?
{ PB(q9gf"1}
return sSiteURL; BY5ODc$
} {8pN]=SaJ~
#]kO/Mr
R_zQiSwG<
public void setSSiteURL(String value) h]jy):9L
{ ;{Nc9d
sSiteURL = value; |[W7&@hF
} ccY! OSae
:Ldx^UO
0@tN3u?dx
public String getSFilePath() v;o/M6GL5
{ (3Dz'X
return sFilePath; o()No_.8H
} d=DQS>Nz
VsQ~Y,7
Fz{T;
public void setSFilePath(String value) i}gsxq%
{ KK';ho,W
sFilePath = value; O63:t$Yx#
} UbEK2&q/8
!zQbF&>
hd1aNaF-
public String getSFileName() l2ARM3"
{ skP'- ^F~
return sFileName; "j/jhe6
} <<Q}|$Wu
w(oi6kg
})yB2Q0
public void setSFileName(String value) gLK_b;:
{ ?J,K[.z
sFileName = value; oe*CZ
} P[%nD cB
REGk2t.L
LEC=@) B
public int getNSplitter() \~> .NH-
{ _J X>#h
return nSplitter; `{1~]?-&
} Q;?rqi ,
Ih<.2
_$P1N^}Zs
public void setNSplitter(int nCount) 0^83:C ^{
{ \h@3dJ4
nSplitter = nCount; awl3|k/
} }0}=-g&
} LaX<2]Tx:
m0p%R>:5
Fv-~v&
/* \A 5Na-/9
**Utility.java o/hj~;(]
*/ VZ$^:.I0
package NetFox; |c[= V?AC
w_P2\B^
R.KznJ
public class Utility { 6E{(_i
2&zklXuo:
(9Of,2]&E
public Utility() X$*]$Ge>
{ K/0Wp %
L./{^)
ML.|\:r*
} Nj{;
9~{,Hj1xE
//线程睡眠 zG)vmysJf
public static void sleep(int nSecond) aen0XiB6~^
{ n.=Zw2FE
try{ ]oLyvG
Thread.sleep(nSecond); a"D'QqtH
} 8osP$"/o
catch(Exception e) )%09j0y>l"
{ 'Pe;Tp>`
e.printStackTrace (); no(or5UJ
} @~bP|a
} LT#EYnG
3<>DDY2bl
//日志 "j8`)XXa(
public static void log(String sMsg) 0"{-<Wot}
{ \U>|^$4 #5
System.err.println(sMsg); g?N^9B,$2
} t=fr`|!
^/I.? :+
b(\Mi_J
public static void log(int sMsg) `R*SHy! _
{ "fC>]iA8I
System.err.println(sMsg); 6^)eW+
} {_4`0J`3
} >en\:pJn)'
On0,#i=
<;*w97n
/* u6Yp,!+
**TestMethod.java TN/y4(j
*/ pM9M8d
package NetFox; ]app9
#nq_R
%-[*G;c'w
public class TestMethod { Z^Yy sf
Xp9] 9H.
tgj5l#P
public TestMethod() LIll@2[
{ ///xx/weblogic60b2_win.exe F!g;}_s9
try{ nrR2U`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6mqp`x`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .hJcK/m
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]&s@5<S[
fileFetch.start(); *M.,Yoj
} n#sK31;yb
catch(Exception e){e.printStackTrace ();} QO:Z8{21So
[X7gP4
??f,(om
} ZiPz~G0[^
\Vpv78QF;
$Gcjm~
public static void main(String[] args) *z};&UsF{
{ I|wC`VgB
new TestMethod(); B`YD>oCN
} CwD=nT5`
} Vjd(Z
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