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)); ]?+{aS-]?k
} jgv`>o%<W
for(int i=0;i<nEndPos.length-1;i++) ;C.S3}
{ i^msjA
nEndPos = nStartPos[i+1]; 8\.b4FNJ
} Yk!/ow@.
nEndPos[nEndPos.length-1] = nFileLength; tc+WWDP#"
} I\O\,yPhhP
} a_~=#]a
k[j90C5
zUJZ`seF
//启动子线程 c9"r6j2m5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;&b.T}Nf06
for(int i=0;i<nStartPos.length;i++) Q\ppfc{,
{ C1kYl0zR[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <ABX0U[*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ifc]K?
nStartPos,nEndPos,i); +0Q,vK#j^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fh$slow4!
fileSplitterFetch.start(); yLE7>48
} M5357Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NPa\Cg[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); co8"sz0(U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SRIA*M.B}
nEndPos = " + nFileLength); ypOLp SYk
// fileSplitterFetch[nPos.length-1].start(); ^TY;Zp
"Jq8?FoT
B;>{0 s
//等待子线程结束 K<`osdp=&
//int count = 0; : 18KR*;p
//是否结束while循环 !9Z r;K~\
boolean breakWhile = false; m0n)dje
r0;:t
YyAJ m^o
while(!bStop) "TyJP[/
{ bNs4 5hDP
write_nPos(); }@ Z56
Utility.sleep(500); V"\0Y0
breakWhile = true; *iBTI+"]
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for(int i=0;i<nStartPos.length;i++) 8BOZh6BV
{ ,l YE
if(!fileSplitterFetch.bDownOver) c/N@zum,{
{ "5R~(+~<@
breakWhile = false; sV"UI
break; i<kD
} _|[UI.a
} ^hNgm.I
if(breakWhile) ajR%c2G;
break; IJYL s
J]lrS
nRL. ppUI
//count++; x+ncc_2n&D
//if(count>4) M5nWVK7c
// siteStop(); B~]5$-
} Qd}m`YW-f$
7w,FX.=;cv
DI+]D~N
System.err.println("文件下载结束！"); Unj.f>U
} voP7"Dl[
catch(Exception e){e.printStackTrace ();} ]^':Bmq
} |F,R&<2
]H-S,lmV
%~L>1ShtU
//获得文件长度 gb ^?l~SS
public long getFileSize() MFTkqbc
{ ;<yd^Xs
int nFileLength = -1; 'o|30LzYgQ
try{ @1.QEyXG
URL url = new URL(siteInfoBean.getSSiteURL()); SDu#Yt&mhh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q_* "SRz
httpConnection.setRequestProperty("User-Agent","NetFox"); S5~VD?O,
HEA#bd\
,@1p$n
int responseCode=httpConnection.getResponseCode(); Dd;Nz
if(responseCode>=400) ];.pK
{ '!l1=cZD
processErrorCode(responseCode); 4wC+S9I#E^
return -2; //-2 represent access is error l^ZI* z7N
} il|1a8M2~
~P~
M@ed>.
String sHeader; q0f3="
^O^l(e!3
:RoBl3X=
for(int i=1;;i++) y_\p=0t8
{ (WJ${OW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?A(QyaKz
//Utility.log(in.readLine()); nKW*Y}VO
sHeader=httpConnection.getHeaderFieldKey(i); x77l~=P+!
if(sHeader!=null) fP.F`V_Y
{ PV|uPuz
if(sHeader.equals("Content-Length")) ^Ge+~o?x
{ T]2q?;N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :'#TCDlOb
break; ]-ZEWt6lsc
} me[DmiM,
} 7AYd!n&S
else $O9^SB
break; Fx-8M!
} !9Aaj<yxm
} T&Lb<'f
catch(IOException e){e.printStackTrace ();} ^i:`ZfA#
catch(Exception e){e.printStackTrace ();} 8_T6_jL<
!\&;h
sC9&Dgkk
Utility.log(nFileLength); TMYd47
I\YV des#
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return nFileLength; h;6lK$!c
} y|'SXM
`jwa<N4e@
7o8{mp'_
//保存下载信息（文件指针位置） V<Z[ nq
private void write_nPos() s kg*
{ ]XI*Wsn
try{ [IK )
output = new DataOutputStream(new FileOutputStream(tmpFile)); R: l&2k@
output.writeInt(nStartPos.length); 76u&EG%
for(int i=0;i<nStartPos.length;i++) `uC@nJ
{ Pp )3(T:
// output.writeLong(nPos); 4;2< ^[M
output.writeLong(fileSplitterFetch.nStartPos); o6V}$wT3J
output.writeLong(fileSplitterFetch.nEndPos); cJ54s}
} #dM9pc jh
output.close(); )/z@vY
} Mn)@{^
catch(IOException e){e.printStackTrace ();} mdRU^n
catch(Exception e){e.printStackTrace ();} aH^RoG}
} &^W|iXi#
wE~V]bmtW
;qrB\j"
//读取保存的下载信息（文件指针位置） Z)jw|T'X
private void read_nPos() {mAU3x
{ i&VsW7
try{ _cXqAo[V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qh`t-
int nCount = input.readInt(); XLH0 ;+CL{
nStartPos = new long[nCount]; {GC?SaK
nEndPos = new long[nCount]; F7Zwh5W
for(int i=0;i<nStartPos.length;i++) ,_Z+8
{ j?MAED
nStartPos = input.readLong(); :_O%/k1\@
nEndPos = input.readLong(); ;<leKcvhQ&
} Q=]w !I\
input.close(); 0}b tXh
} ^<e.]F25M
catch(IOException e){e.printStackTrace ();} \EVBwE,
catch(Exception e){e.printStackTrace ();} U\Z?taXB
} qHxqQ'ks;
y\a1iy
je!-J8{
private void processErrorCode(int nErrorCode) b,CaWg
{ WL'P)lI5
System.err.println("Error Code : " + nErrorCode); ]MxC_V+P`
} {7)st W
Z,=7Tu bR#
Y'ow
//停止文件下载 B[KJR?>
public void siteStop() aoXb22]{
{ mya_4I m
bStop = true; ;Rv!k&Df
for(int i=0;i<nStartPos.length;i++) /kfgx{jZ
fileSplitterFetch.splitterStop(); ['T:ea6B
C+TI]{t
P'`r
} )a-Du$kd
} }2e??3
//负责部分文件的抓取 hRCed4qA
**FileSplitterFetch.java /Z$&pqs!
*/ ~8]NK&J
package NetFox; dxmE3*b`
YxP&7oq
7(5 4/
import java.io.*; q}]XYys
import java.net.*; 62Z#YQ}x
[Nk3|u`h
?:)]h c
public class FileSplitterFetch extends Thread { !1ED~3/X
Z /9>
CO`_^7o9(
String sURL; //File URL 6b:tyQ
long nStartPos; //File Snippet Start Position sJDas,7>
long nEndPos; //File Snippet End Position #Y4=J 6
int nThreadID; //Thread's ID 1~PV[2a
boolean bDownOver = false; //Downing is over :$n=$C-wp
boolean bStop = false; //Stop identical #E&80#Z5
FileAccessI fileAccessI = null; //File Access interface {j7uv"|X7
A -b [>}_
*m#Za<_Gv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yrlf+tl
{ AT%u%cE-
this.sURL = sURL; 'hs2RSq
this.nStartPos = nStart; o}$EG
this.nEndPos = nEnd; 2* 2wY=
nThreadID = id; }yz (xH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *3?'4"B{8
} Dp':oJC
iB498t
3J5!oF{H
public void run() ^3UGV*Ypk
{ 2'W<h)m)z
while(nStartPos < nEndPos && !bStop) wbst8*$
{ k<"oiCE
[DF,^4g
7D;cw\ |
try{ Gy6l<:;
URL url = new URL(sURL); } x2DT8u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]4pkcV P
httpConnection.setRequestProperty("User-Agent","NetFox"); @CT;g\4
String sProperty = "bytes="+nStartPos+"-"; FGoy8+nB1M
httpConnection.setRequestProperty("RANGE",sProperty); 8/=L2fNN[
Utility.log(sProperty); dzDqZQY$
z[3L2U~6
+w+}b^4
InputStream input = httpConnection.getInputStream(); lhBT@5Dm9
//logResponseHead(httpConnection); pNKhc#-w
#n#@fAY
/|D*w^>
byte[] b = new byte[1024]; tQBRA/
int nRead; , T8>}U(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6e[VgN-s
{ {\:{[{qF
nStartPos += fileAccessI.write(b,0,nRead); D>LZP!
//if(nThreadID == 1) 5Er2}KZJv,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *^:N.&]
} \Z+z?K O
9T*v9d
FSA1gAW6g
Utility.log("Thread " + nThreadID + " is over!"); iLkZ"X.'|1
bDownOver = true; %|^fi8!:|
//nPos = fileAccessI.write (b,0,nRead); <OIIoB?t
} dF2nEaN0%
catch(Exception e){e.printStackTrace ();} 4x 8)gE
} =fO5cA6Z
} /!3@]xz*
PEW=@xj2y
'LE=6{#
//打印回应的头信息 }n4V|f-
public void logResponseHead(HttpURLConnection con) #~<0t(3Q
{ /\4'ddGU
for(int i=1;;i++) vy\RcP
{ U 15H2-`
String header=con.getHeaderFieldKey(i); T-U}QM_e
if(header!=null) 'LO^<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :gep:4&u
Utility.log(header+" : "+con.getHeaderField(header)); 2fWTY0
else "-vW,7y
break; f PM8f
} *U P@9D
} EV*IoE$W]=
d%V*|0c)
tF{D= ;G
public void splitterStop() w tiny,6
{ i:OK8Q{VI
bStop = true; Bg|5KOnd
} 4X+ifZO
Y07ZB'K
'.81zpff
} SAyufLEv,
@T'i/}nl
kNobl
/* _s .G
**FileAccess.java *%S"eWb
*//文件访问(定位，写) ?B}{GL2)
package NetFox; $h*L=t(
import java.io.*; 8n*.).33
<w)r`D6
)'6DNa[y
public class FileAccessI implements Serializable{ t+1 %RyKFB
TjwBv6h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^$'z!+QRM
RandomAccessFile oSavedFile; p IU&^yX>
long nPos; ]]oI#*c
f]\CD<g3|E
R'!
public FileAccessI() throws IOException /XzH?n/{R
{ {;:/-0s
this("",0); IHcD*zQ
} 9mmCp&~Z
ucG@?@JENm
6 1F(<!
public FileAccessI(String sName,long nPos) throws IOException 93` AWg/T
{ 3v5%y'
oSavedFile = new RandomAccessFile(sName,"rw"); G"Sd@%W(
this.nPos = nPos; :[hgxJu+
oSavedFile.seek(nPos); +/)#( j@
} S|]X'f
b-{=s+:
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public synchronized int write(byte[] b,int nStart,int nLen) TwVlg;
{ \<y#R~7s
int n = -1; ?MgUY)X
try{ 2&^]k`Aj6D
oSavedFile.write(b,nStart,nLen); ihP|E,L=L
n = nLen; YW60q0:
} A8oo@z68n>
catch(IOException e) /7t>TYip!
{ ](wvu(y\E
e.printStackTrace (); Ns7(j-
} Q2F+?w;,
o'f?YZ$.
{:]9Q Tq
return n; Pyb Z)5u
} LRb{hUt=
p%*%n3bw
jN6uT&{T
} ~==>pj
@EnuJe
n=c 2Kc
/* ]jmL]Ny^
**SiteInfoBean.java 5`gQ~
*/ e0T34x'
package NetFox; vfE6Ggz
ysQ,)QoiR{
f-E("o
public class SiteInfoBean { t 0|!(3
5[YDZ7g"~
fM^qQM[lG
private String sSiteURL; //Site's URL PSZL2iGj9V
private String sFilePath; //Saved File's Path NR5oIKP?
private String sFileName; //Saved File's Name qx4I_%
private int nSplitter; //Count of Splited Downloading File IbP#_Vt
|,!IZ- th
8$;=Uf,x
public SiteInfoBean() ]2\VweV
{//nSplitter的缺省值为5 _PlKhv}
//default value of nSplitter is 5 )Ccq4i
this("","","",5); pXtXjb
} j{9D{
Y!gCMLL
8F&=a,ps[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qIIv6''5@
{ h?8]C#6^
sSiteURL= sURL; }9W4"e2)
sFilePath = sPath; ?l^1 *Q,
sFileName = sName; zN"J}r:
this.nSplitter = nSpiltter; Ko&>C_N
@)4]b+8Z
$}jssnoU
} YtfVD7m
j&Wl0
>w^YO25q
public String getSSiteURL() k+8q{5>A<
{ @vrV*!
return sSiteURL; s!}ne"&0
} KNLfp1!
nEkR1^30
e[/dv)J
public void setSSiteURL(String value) Yo("U8:XX
{ Vy938qX
sSiteURL = value; <-D0u?8
} w$`5g
e^[H[d.WMC
1PP $XJtyD
public String getSFilePath() ~ ArP9 K"
{ HO}Hh[{V9
return sFilePath; 2g>SHS@1>
} ~(IB0=A{v
i2&ed_h<?
_cJ2\`M
public void setSFilePath(String value) -cSP_1
{ LM-J !44
sFilePath = value; hijgF@
} GrAujc5|
pn.T~"%
'_/Bp4i
public String getSFileName() fmiz,$O4?
{ x>*Drm 7
return sFileName; v!ujj5-$I
} uec!RKE
x\s|n{
^,;z|f'%*
public void setSFileName(String value) Tp_L%F
{ KFvQ
sFileName = value; %d(^d
} .%Ta]!0
X~<("
*EZHJt9
public int getNSplitter() e*;c(3>(
{ ulkJR-""&
return nSplitter; (Xq)py9
} )Ib<F7v
*i- _6s
cgm~>
public void setNSplitter(int nCount) L.1_(3NG
{ ]b%Hy
nSplitter = nCount; Wr3mQU
} [I$BmGQ
} 8qu2iPOcZ
}=6'MjF]
0VGPEKRh
/* L_+k12lm
**Utility.java k'IYA#T6
*/ }c`fW&
package NetFox; _;~,Cgfi
I]&#Dl/
F;l$.9?.s
public class Utility { OQ>x5?um
mysetv&5
Rx);7j/5
public Utility() nZ@&2YPlem
{ 8&3V#sn'
w[!^;#
.$%Soyr?,
} 'C ~y5j
L}}y'^(
//线程睡眠 _&j}<K$-(
public static void sleep(int nSecond) _`_%Y(Xat
{ w - Pk7I
try{ 'eJ+JM<0%
Thread.sleep(nSecond); bD[!/'4eJ
} M5*{
catch(Exception e) I{lT>go
{ 7A\~)U@
e.printStackTrace (); #L{OV)a<
} 3'c0#h@VD
} jGEt+\"/QJ
D!.+Y-+Xzu
//日志 P~G1EK|4
public static void log(String sMsg) ;zIP,PMM
{ spGB)k,^
System.err.println(sMsg); |/2y-[;:
} yI ld75S`
eXKo.JL
C#t'Y*
public static void log(int sMsg) t7m>A-I
{ |pmZ.r
System.err.println(sMsg); LwK+:4$
} u)V#S:9]
} q&Gz ]
eOXHQjuj
&p}$J)q
/* 8 XICF
**TestMethod.java $`wMX{
*/ VsN pHQG]
package NetFox; awOd_![c'
mFSw@CC
0\:(ageY?
public class TestMethod { H'LD}\K l
't_[dSO
;Ww7"-=sw
public TestMethod() ??i,Vr@)w
{ ///xx/weblogic60b2_win.exe {2+L@
try{ Mnz!nWhk
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~5 *5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _`I"0.B]
SiteFileFetch fileFetch = new SiteFileFetch(bean); F@*+{1R
fileFetch.start(); )QG<f{wS
} qOUqs'7/]
catch(Exception e){e.printStackTrace ();} aAA9$
3nu^l'WQ
+=mkCU
} Y;e,Gq`
sz)oZPu|
']>Mp#j
public static void main(String[] args) E6,4RuCK
{ ObE,$_ k
new TestMethod(); ;+tpvnV;]
} GD:4"$)[o
} >9f%@uSM$3
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