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)); pf2$%lE
} 1"!<e$&$X
for(int i=0;i<nEndPos.length-1;i++) F<^,j7@
{ ^Yn6kF
nEndPos = nStartPos[i+1]; 5E.cJ{
} ^ qE4:|e
nEndPos[nEndPos.length-1] = nFileLength; )@Bt[mfrVD
} j.m-6
} k_y@vW3
{&2$1p/9'
O:u^jcXA
//启动子线程 <89js87
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \x|(`;{
for(int i=0;i<nStartPos.length;i++) {yfG_J
{ kvo741RO6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kmP0gT{Sj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0TVO'$Gvi
nStartPos,nEndPos,i); 5))?,YkrrI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |5Z@7
fileSplitterFetch.start(); ff{ESFtD
} `T~M:\^D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^:DlrI$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); - +>~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9g 2x+@5T^
nEndPos = " + nFileLength); Z9!goI
// fileSplitterFetch[nPos.length-1].start(); -`Z5#8P
xXHz)w
op"Cc
//等待子线程结束 }uZhoA
//int count = 0; hL8QA!
//是否结束while循环 q Rtgk
boolean breakWhile = false; .[CXW2k
4>, <b1Y
S&]JY
while(!bStop) r]8B6iV
{ 4RdpROK
write_nPos(); B8;ZOLAU
Utility.sleep(500); d B?I(
breakWhile = true; H]}- U8}sp
z3a te^PJF
,@[Q:fY
for(int i=0;i<nStartPos.length;i++) VF6@;5p
{ pX!S*(Q{
if(!fileSplitterFetch.bDownOver) ;jnnCXp>
{ q4U?}=PD
breakWhile = false; fT 8"1f|w
break; w0Us8JNGz
} Gb8LW,$IT-
} VJ1si0vWtq
if(breakWhile) o'yR^`
break; X1A;MA@0Ro
&5zUk++
i5-V$Qh
//count++; |e+I5
//if(count>4) BT`6v+,h7k
// siteStop(); *h]qh20t
} /e\} qq
]YwIuz6]
xu_Tocvop
System.err.println("文件下载结束！"); "qwRcuHY
} iRPd=)
catch(Exception e){e.printStackTrace ();} @++ X H}
} ( XE`,#
~A"ODLgU9
tCA |sN
//获得文件长度 )V9$ P)
public long getFileSize() 5*4P_q(AxD
{ TmO\!`
int nFileLength = -1; 0w(<pNA
try{ ~LkReQI
URL url = new URL(siteInfoBean.getSSiteURL()); r^Gl~sX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5"@<7/2qI
httpConnection.setRequestProperty("User-Agent","NetFox"); {uw'7 d/
bZ%[ON5OY
xb1)ZJH
int responseCode=httpConnection.getResponseCode(); 8mx5K-/,y^
if(responseCode>=400) '+-R 7#
{ yqCy`TK8
processErrorCode(responseCode); ^=W%G^jJy
return -2; //-2 represent access is error SDTX0v
} $\0j:<o
:X@;XEol~
spFsrB
String sHeader; \`4}h[
DY,Sfh;tp
nA+[[(6
for(int i=1;;i++) S: /ShT
{ 9}3W0F;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /$ L;m
//Utility.log(in.readLine()); 1!=$3]l0Lj
sHeader=httpConnection.getHeaderFieldKey(i); -4X,x
if(sHeader!=null) \Z57UNI
{ UVU}
if(sHeader.equals("Content-Length")) ~r|.GY
{ 9X=#wh,q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e2Xx7*vS
break; v*#Z{)r
} )vy<q/o+
} O|av(F9
else %yptML9
break; ,riwxl5*E/
} B#q5Ut
} 62Jn8DwAT
catch(IOException e){e.printStackTrace ();} HlV3rYh
catch(Exception e){e.printStackTrace ();} u}#rS%SF*
p>R F4
y(N-1
Utility.log(nFileLength); BPi>SI0
R2M,VK?Wx
RV&2y=eb
return nFileLength; G#lzB`i
} 9:@os0^O
|5g*pXu{
I]
//保存下载信息（文件指针位置） d(fgv
private void write_nPos() TcRnjsY$
{ {4:En;
try{ #=$4U!yL
output = new DataOutputStream(new FileOutputStream(tmpFile)); a^sR?.+3
output.writeInt(nStartPos.length); *~fN^{B'!
for(int i=0;i<nStartPos.length;i++) 4e*0kItC
{ %zX'u.}8#
// output.writeLong(nPos); f+/^1~^
output.writeLong(fileSplitterFetch.nStartPos); 6bqJM#y@
output.writeLong(fileSplitterFetch.nEndPos); 21cIWvy
} 2|Tt3/Rn
output.close(); ,PIdPaV--
} h8S%Q|-
catch(IOException e){e.printStackTrace ();} b^A&K@[W#,
catch(Exception e){e.printStackTrace ();} 0BE%~W
} 2%WZ-l!i
eKu&_q
6`+DBr
//读取保存的下载信息（文件指针位置） #0^QUOp
private void read_nPos() Ro%S_!
{ ]qpcA6%a|
try{ ;tKL/eI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GWP"i77y0s
int nCount = input.readInt(); kZn!]TseN
nStartPos = new long[nCount]; }Efp{E
nEndPos = new long[nCount]; vTB*J,6.
for(int i=0;i<nStartPos.length;i++) q F}5mUcZ4
{ rj{'X /
nStartPos = input.readLong(); pX*mX]
nEndPos = input.readLong(); d2(eX\56Z
} {CGk5`g~
input.close(); $p9XXZ"*
} .h*&$c/l
catch(IOException e){e.printStackTrace ();} 29GejLg|
catch(Exception e){e.printStackTrace ();} Y,)9{T
} r3*wH1n
g%\e80~1(
pp{%\td
private void processErrorCode(int nErrorCode) NT8%{>F`
{ gW*ee
System.err.println("Error Code : " + nErrorCode); ^?juY}rZ=|
} *|`'L
X;}_[=-
o}Xp-P
//停止文件下载 2y<d@z:K
public void siteStop() bNL E=#ro
{ }hBv?B2/1
bStop = true; 0+S:2i/G
for(int i=0;i<nStartPos.length;i++) WMI/Y9N
fileSplitterFetch.splitterStop(); `zep`j&8^
6XX5K@
4&&j7$aV
} EIF[e|kZ<
} oxad}Y
//负责部分文件的抓取 t zV"|s=o
**FileSplitterFetch.java JG4&eK$-
*/ neZ_TT/3K
package NetFox; )p!dqlK
esLY1c%"/
#}jf TM
import java.io.*; xK_$^c.
import java.net.*; :z"Uw*
-D V;{8U4
3^`bf=R
public class FileSplitterFetch extends Thread { w=f8UtY9@A
Ni0lj:
bUWtlg
String sURL; //File URL 1hMk\ -3S
long nStartPos; //File Snippet Start Position I#A`fJ
long nEndPos; //File Snippet End Position j+Tk|GRab
int nThreadID; //Thread's ID JLG5`{
boolean bDownOver = false; //Downing is over e`_3= kI
boolean bStop = false; //Stop identical V];RQWs
FileAccessI fileAccessI = null; //File Access interface .y'OoDe
K}$PIW
ev+NKUi=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vhUuf+P*
{ (d!vm\-PH
this.sURL = sURL; >|rL0
this.nStartPos = nStart; Bq2}nDP
this.nEndPos = nEnd; LLU>c]a
nThreadID = id; d3 N %V.w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9r)5d&,6
} rAQ^:q
$~9U-B\
( NiuAy
public void run() oYqC"g&4Z
{ m<076O4|`
while(nStartPos < nEndPos && !bStop) hA~}6Qn
{ D@Wm-
KztF#[64W^
lL83LhE}<
try{ G-:DMjvN
URL url = new URL(sURL); WK<pZ *x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @yek6E&9
httpConnection.setRequestProperty("User-Agent","NetFox"); GvVuFS>y
String sProperty = "bytes="+nStartPos+"-"; YE-kdzff
httpConnection.setRequestProperty("RANGE",sProperty); 6!gGWn5>}
Utility.log(sProperty); >! c^
|0Zj/1<$
+~[19'GH
InputStream input = httpConnection.getInputStream(); <4>6k7W
//logResponseHead(httpConnection); bRIb'%=+GA
<LLSUk/
}u|0
byte[] b = new byte[1024]; 1-b,X]i
int nRead; \tQi7yj4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ep'C FNbtW
{ xt-;7
nStartPos += fileAccessI.write(b,0,nRead); y24 0 +;a
//if(nThreadID == 1) fh2Pn!h+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w}2yi#E[
} dvxH:,
7"S|GEs:
kPxrI=
Utility.log("Thread " + nThreadID + " is over!"); g xLA1]>{
bDownOver = true; Z> &PM06
//nPos = fileAccessI.write (b,0,nRead); QVFa<>8/md
} JEAqSZak#
catch(Exception e){e.printStackTrace ();} Z2LG/R
} {!EbGIh
} "%Rx;xw|
P|6m%y
,Wdyg8&.
//打印回应的头信息 )^r4|WYyt
public void logResponseHead(HttpURLConnection con) D)!k
{ b>waxQxjS
for(int i=1;;i++) #}vcffgZ
{ nGuF,0j
String header=con.getHeaderFieldKey(i); WIhf*LF"
if(header!=null) ?Dfgyz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *X)OdU
Utility.log(header+" : "+con.getHeaderField(header)); B)c.`cfr*\
else #6YNgJNk
break; a-kU?&* y
} !WIL|\jbh
} lvFHr}W
&XZ>}^lD^
PSy=O\
public void splitterStop() ]w')~yk
{ .rMGI"
bStop = true; y%T'e(5Ed
} 9> (8r+
\@80Z5?n
4sva%Up
} WIbU^WJ0
7sFjO/a*
)X7ZX#ttH
/* mM95BUB
**FileAccess.java 1 8&^k|
*//文件访问(定位，写) S]9xqiJW
package NetFox; Q"(i
import java.io.*; yX)2 hj:s
x2nNkd0h
?HBc7$nW
public class FileAccessI implements Serializable{ ?Jx8z`(
?=fJu\;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gFW1Nm_DJ
RandomAccessFile oSavedFile; PgxU;N7Y
long nPos; 0ogTQ`2Z:
9x:c"S*
<4VUzgX2
public FileAccessI() throws IOException 3 =S.-
{ f:=?"MX7
this("",0); $A-b-`X
} rA_e3L@v#[
=?/J.[)<*
\?}ZXKuJj
public FileAccessI(String sName,long nPos) throws IOException ABx0IdOcI
{ {Ji[d.cY
oSavedFile = new RandomAccessFile(sName,"rw"); fdPg{3x*k
this.nPos = nPos; iveWau292
oSavedFile.seek(nPos); <7)@Jds\
} /FQumqbnt
gsZCWT
he!e~5<@y
public synchronized int write(byte[] b,int nStart,int nLen) ]pFYAe ?
{ u9?85
int n = -1; 7o;}"Y1
try{ _p90Zm-3X
oSavedFile.write(b,nStart,nLen); d_OHQpfK
n = nLen; Ypp>7J/
} v/(< fI^
catch(IOException e) Dn9Ta}miTO
{ T3Tk:r
e.printStackTrace (); 0chBw~@*s
} d*!,McBn
7?F0~[eGG
W>h[aVTO
return n; 6r^(VT
} =b6Q2s,i
\.}* s]6
5Rc 5/m
} G<>`O;i
fUE jl
2!l)%F`
/* /#.6IV(
**SiteInfoBean.java &"25a[x{B
*/ tcmG>^YM
package NetFox; {@({po
]ul]L R%.
aP2
public class SiteInfoBean { VFRUiz/C
!K3 #4
sg2T)^*V
private String sSiteURL; //Site's URL ( vgoG5
private String sFilePath; //Saved File's Path (?$}Vp
private String sFileName; //Saved File's Name $n>.;CV
private int nSplitter; //Count of Splited Downloading File 8+lM6O ~!
<@JK;qm>S
RW%e%
public SiteInfoBean() 3d \bB !
{//nSplitter的缺省值为5 |r6<DEg
//default value of nSplitter is 5 X}_kLfP/9
this("","","",5); &;*jMu6
} &i6WVNGy
k;q|pQ[
Xul<,U~w6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c"6<p5j!
{ ,7<5dIdZ
sSiteURL= sURL; ECQ>VeP
sFilePath = sPath; <Ms,0YKx
sFileName = sName; bT0CQ_g21
this.nSplitter = nSpiltter; h_fA
=Cu!
"Bn!<h}mg
} #6@7XC
>e'6RZRLA
@G^ l`%
public String getSSiteURL() Nx,.4CI
{ /tDwgxJ
return sSiteURL; OZDnU6
} e=Kf<ZQt
sBB>O@4
FG'F]fc%
public void setSSiteURL(String value) r+d%*Dx
{ .kyp5CD}4
sSiteURL = value; vm 1vX;
} "0pu_
IL*C/y
l/#;GYB]
public String getSFilePath() 4f'1g1@$
{ p^MV<}kk
return sFilePath; 8<{)|GoqB
} ]uG9WT6l
L;wzvz\+
hZ[,.
public void setSFilePath(String value) Q6]SsV?x
{ o@XhL9
sFilePath = value; hCuUX)>Bt
} j/ow8Jmc*
,_F@9Up
^FIpkhw
public String getSFileName() s<h]2W
{ :I[nA?d[&
return sFileName; STtjkZ6
} sZxf.
$!H;,Jxv
.}=gr+<bf
public void setSFileName(String value) s\@RJ[(<
{ Mj2`p#5wKh
sFileName = value; lhZXq!2p
} >;:235'(M
7A<X!a
"**Tw'
public int getNSplitter() 4"at~K` Q
{ Py_yIwQqg
return nSplitter; `O/1aW1
} RoS&oGYqR
0go{gUI
YHSdaocp
public void setNSplitter(int nCount) FhpS#,Y$
{ 1P;J%.{
nSplitter = nCount; KP,#x$Bg
} 1Tm,#o
} "}fJ 2G3
bvzNur_
mmRxs1 0$
/* rom`%qp^
**Utility.java +#ufW%ZG
*/ -Ri/I4Xj
package NetFox; <A@}C+
e98f+,E/
|zd+ \o
public class Utility { AWo\u!j
UNY O P{
!Pd@0n4
public Utility() "{>BP$Jz
{ n-P<y
1u>[0<U~E
,yf2kU
} !p #m?|Km
N5_`
//线程睡眠 wo>7^ZA
public static void sleep(int nSecond) ,58XLu
{ {8]Yqx)1]]
try{ @:s(L]
Thread.sleep(nSecond); )seeBm-`
} Wz{,N07Q#{
catch(Exception e) ^1`Mz<
{ %j $r"
e.printStackTrace (); ]WFr5
} Z#uxa
} (r*"}"ZG
c6-~PKJL
//日志 KJ (|skO
public static void log(String sMsg) =2XAQiUR\
{ -,:^dxE'
System.err.println(sMsg); }ZqnsLu[)
} )?y${T
}jdMo83
@qUgp*+{
public static void log(int sMsg) ~ p~
{ 6K Cv
System.err.println(sMsg); )>"|<h.2]
} tW-wO[2
} " l;=jk]
7!sR%h5p
:Eb=jWA
/* s$g3__|Y
**TestMethod.java E5iNuJj=f
*/ CWdpF>En
package NetFox; #M ;j*IBl*
Dbl3ef
Nb3uDA5R
public class TestMethod { WQiIS0BJ *
^tFlA)
[b:0j-
public TestMethod() 3QhQpPk),
{ ///xx/weblogic60b2_win.exe k^@dDLr"
try{ #IvHxSo&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3-Bz5sj9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0?,<7}"<X
SiteFileFetch fileFetch = new SiteFileFetch(bean); S\M+*:7
fileFetch.start(); KOhK#t>H@0
} awB+B8^s
catch(Exception e){e.printStackTrace ();} U%rEW[j
A<}nXHs-
YQ|o0>
} e+~@"^|
g|Tkl
-JfqY?Ue_2
public static void main(String[] args) `c)[aP{vN
{ 9y}/ G
new TestMethod(); )k[{re
} Xl,707
} %`bn=~T^
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