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)); w|G7h=
} fPTLPcPP
for(int i=0;i<nEndPos.length-1;i++) ih)\P0wed
{ >{Ayzz>v
nEndPos = nStartPos[i+1]; 1^]IuPxq
} N}/V2K]Q
nEndPos[nEndPos.length-1] = nFileLength; pWE(?d_M{G
} uG'S&8i_
} h(@.bt#
=),ZZD#J
ASEKP(]v
//启动子线程 i;~.kgtq4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :-59~8&
for(int i=0;i<nStartPos.length;i++) W"s/8;
{ nT:<_'!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p&\QkI=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pFMJG<W9,
nStartPos,nEndPos,i); OD[=fR|cp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U&(gNuR>J
fileSplitterFetch.start(); :s+?"'DP
} k {{eyC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ._p2"<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]Z UE !
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", < (9 BO&
nEndPos = " + nFileLength); %ho?KU2j
// fileSplitterFetch[nPos.length-1].start(); LR.]&(kyd
!_+FuF"@
_)pOkS
//等待子线程结束 *eXs7"H
//int count = 0; OSuQ7V
//是否结束while循环 !ckluj
boolean breakWhile = false; IX 6 jb"
}Uj-R3]}K
HrLws95'
while(!bStop) _~1O#*|4
{ eCJtNPd
write_nPos(); EpACd8Fb
Utility.sleep(500); $[HCetaqV
breakWhile = true; w$s6NBF7
xv>8rW(Np5
9`qw,X&AK_
for(int i=0;i<nStartPos.length;i++) WllQM,h
{ Ot=nKdP}D
if(!fileSplitterFetch.bDownOver) 9:%')M&Q
{ i\ 7JQZ
breakWhile = false; 1)}hzA
break; u-.5rH l
} #Q_Scxf
} !j #8zN
if(breakWhile) Qg1kF^=
break; Iw] ylp
DI-&P3iGx
oEZhKVyc.y
//count++; =j w?*
//if(count>4) zvnd@y{[
// siteStop(); +`S_Gy
} evE:FiDm(j
r;(^]Soz
8:I-?z;S
System.err.println("文件下载结束！"); StNA(+rT
} +Y+fM
catch(Exception e){e.printStackTrace ();} 0%rE*h9+
} wmbG$T%k
Mf5*Wjz.Mc
4Af7x6a;
//获得文件长度 DcRoW
public long getFileSize() }`0=\cKqn
{ 6L~5qbQ
int nFileLength = -1; S{XO3
try{ \qW^AD(it<
URL url = new URL(siteInfoBean.getSSiteURL()); T|$tQgY^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l9%ckC*q
httpConnection.setRequestProperty("User-Agent","NetFox"); ZZ}HgPZ
B|^=2 >8s
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int responseCode=httpConnection.getResponseCode(); dZkKAK:v
if(responseCode>=400) +sZY0(|K8
{ FD~uUZTM
processErrorCode(responseCode); #Wl9[W/4
return -2; //-2 represent access is error 'g<FL`iP
} AKLFUk
Y!c7P,cZ+3
`} 'o2oZnG
String sHeader; FFVh~em{
Xa'b@*o&
&F0>V o
for(int i=1;;i++) =`MQKh,
{ |gk"~D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LDo~
//Utility.log(in.readLine()); ?*q-u9s9
sHeader=httpConnection.getHeaderFieldKey(i); rV%;d[LB
if(sHeader!=null) MnY}U",
{ './qBJ
if(sHeader.equals("Content-Length")) $Vs5d=B
{ 8v^AVg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ? R[GSS1
break; >A L^y(G
} j=Q ?d]
} h=au`o&CG
else SrdCLT8
break; dqt}:^L*0g
} LmROG-9
} zU|'IW&
catch(IOException e){e.printStackTrace ();} 5NKyF
catch(Exception e){e.printStackTrace ();} }&Xf<6
Z2]\k|%<Fa
ZOJ7^g
Utility.log(nFileLength); ,/p.!+
)q{e L$
i94)DWZ^
return nFileLength; 6l|SGt\
} WR*<|
cR6#$-a
O~Dm|hP
//保存下载信息（文件指针位置） (iO/@iw
private void write_nPos() n5#9o},oK
{ m0Uk*~Gz
try{ ]>(pQD
output = new DataOutputStream(new FileOutputStream(tmpFile)); kI*f}3)Y
output.writeInt(nStartPos.length); unN*L
for(int i=0;i<nStartPos.length;i++) kkT=g^D9j
{ FePWr7Ze
// output.writeLong(nPos); RDqQ6(e"
output.writeLong(fileSplitterFetch.nStartPos); :WSszak
output.writeLong(fileSplitterFetch.nEndPos); OOz;/kay
} 2DBFY1[Pk
output.close(); 5.Nc6$ N
} i[e-dT:*R
catch(IOException e){e.printStackTrace ();} 6,p;8I
catch(Exception e){e.printStackTrace ();} /-ewCCzZV
} "? 5@j/ e`
-A"0mS8L
l2 #^}-
//读取保存的下载信息（文件指针位置） >lK:~~1
private void read_nPos() GtqA@&5&
{ q+67Wc=
try{ g.Kyfs4`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !xC IvKW
int nCount = input.readInt(); 9aKCO4
nStartPos = new long[nCount]; _ba.oIc
nEndPos = new long[nCount]; x@VZJrQQ
for(int i=0;i<nStartPos.length;i++) N2EX`@_2
{ Ymcc|u6$"
nStartPos = input.readLong(); sGbk4g
nEndPos = input.readLong(); _7-P8"m
} H#I%6k*\a
input.close(); }~NWOJ3;
} {0} Q5
catch(IOException e){e.printStackTrace ();} JZrZDW>M
catch(Exception e){e.printStackTrace ();} B}h8c
} J#k.!]r,Y
^;mGOjS
rx(z::
private void processErrorCode(int nErrorCode) q9m-d-!)
{ ]K>x:vMKH
System.err.println("Error Code : " + nErrorCode); 4 eP-yi
} 4d @ (>
upF^k%<y:
Dj{t[z]$k
//停止文件下载 S6|L !pO
public void siteStop() Ha!]*wg#
{ BIEeHN4
bStop = true; 8:Jc2K
for(int i=0;i<nStartPos.length;i++) ')v<MqBr
fileSplitterFetch.splitterStop(); 6[C>"s}Ol
]0@ J)Z09
q;qY#wD@
} JiHk`e`
} n@| &jh
//负责部分文件的抓取 D5fhOq+g
**FileSplitterFetch.java i<uk}
*/ I/w=!Ih
package NetFox; pS<j>y
cvv(OkC
0VlB7oF
import java.io.*; y{uN+QS
import java.net.*; VTJ,;p_UH
\_zp4Xb2
! ^U!T\qDi
public class FileSplitterFetch extends Thread { 92Df.xI}
Z<Ke/Xi
8G p%Q
String sURL; //File URL gK"E4{y_@
long nStartPos; //File Snippet Start Position JNgl
long nEndPos; //File Snippet End Position S"joXmJ/-C
int nThreadID; //Thread's ID b+ v!3|
boolean bDownOver = false; //Downing is over J*'#! xIa
boolean bStop = false; //Stop identical "( P-VX
FileAccessI fileAccessI = null; //File Access interface #Q_ d
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XnI)s^
{ >Sh"/3%q
this.sURL = sURL; 6):^m{RH^
this.nStartPos = nStart; l?LP:;S
this.nEndPos = nEnd; Lr`G. e
nThreadID = id; B[6y2+6$0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .6nNqGua1
} C Ejf&n
=^A/&[&31
z>./lu\
public void run() +oMe\wYR$r
{ q`DilZ]S
while(nStartPos < nEndPos && !bStop) h$y0>eMWs
{ s+yX82Y
C'jE'B5b
Qh. : N
try{ a6fqtkZ x
URL url = new URL(sURL); /6@Wm?`DB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H-aSLc
httpConnection.setRequestProperty("User-Agent","NetFox"); WAt| J2
String sProperty = "bytes="+nStartPos+"-"; } h pTS_
httpConnection.setRequestProperty("RANGE",sProperty); Y^W.gGM
Utility.log(sProperty); D%k]D/
Z39I*-6F9W
]@MBE1M
InputStream input = httpConnection.getInputStream(); c'r7sI%Yi
//logResponseHead(httpConnection); qdeS*rp\
-P>f2It
w-.=u3
byte[] b = new byte[1024]; m"Y|xvIA
int nRead; BJi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cfEi]
{ 2m/=0sb\{
nStartPos += fileAccessI.write(b,0,nRead); 'v*Y7zZ#K
//if(nThreadID == 1) BVpRkUC"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L=wg"$
} hhVyz{u
^Q$U.sN?R
MHVHEwr.{
Utility.log("Thread " + nThreadID + " is over!"); e+5]l>3)f
bDownOver = true; GGR hM1II
//nPos = fileAccessI.write (b,0,nRead); ")87GQ(R
} 'cx&:s
catch(Exception e){e.printStackTrace ();} g5*Zg_G/
} M4:}`p=
} iB,Nqs3i*
u.s-/ g
$zvqjT:>
//打印回应的头信息 <U ?_-0
public void logResponseHead(HttpURLConnection con) Jj$N3UCg7
{ ch%-Cg~%
for(int i=1;;i++) ~~_!&
{ DxLN{g]B
String header=con.getHeaderFieldKey(i); pkR+H|
if(header!=null) ?u9JRXj%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >=_Z\ wA
Utility.log(header+" : "+con.getHeaderField(header)); P|OjtI
else ,^UNQO*{GI
break; `/mcjKQ&9y
} iYJzSVO
} do:3aP'S,
!?7c2QRN
_bO4s#yI
public void splitterStop() IW.~I,!x
{ =A,6KY=E
bStop = true; }I\hOL
} \*V`w@
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n^Qt !~
} T*%Q s&x;
c?NXX&
zl W5$cC[
/* -nQ:RHnd
**FileAccess.java d|9B3I*I
*//文件访问(定位，写) Lit@ m2{\
package NetFox; tDl1UX
import java.io.*; K)AJx"
Q`dzn=
P2S$Dk_<\X
public class FileAccessI implements Serializable{ #UcqKq
+([ iCL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CmNd0S4v
RandomAccessFile oSavedFile; NiwJ$Ah~X
long nPos; #O<2wMb2<
s4RqMO5eI
^uu)|
public FileAccessI() throws IOException Olg@ Ri
{ {/x["2a1
this("",0); APgP*,
} ,rB"ag !
{:VUu?5-t;
szY=N7\S*
public FileAccessI(String sName,long nPos) throws IOException k{op,n#
{ Q]Fm4
oSavedFile = new RandomAccessFile(sName,"rw"); /=zzym~<>
this.nPos = nPos; 4wZ{Z 2w
oSavedFile.seek(nPos); CV~\xYY
} `i8KIE
)|88wa(M
abq$OI
public synchronized int write(byte[] b,int nStart,int nLen) \#.@*?fk
{ 9}{i8 <$=
int n = -1; A d0dg2Gw
try{ Cc?BJ
oSavedFile.write(b,nStart,nLen); / ;U
n = nLen; B*+3A!{s
} idLysxN
catch(IOException e) @Fp-6J
{ !vU$^>zo~
e.printStackTrace (); L--
} %=:*yf>}
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q][{?
return n; :GU6v4u
} edh?I1/
*RQkL'tRf
"JLKO${ Y
} 7a@%^G @!
R6ynL([xh
}U=|{@%
/* %z6.}4h
**SiteInfoBean.java '1lr "}"Q+
*/ 1sL#XB$@N
package NetFox; L~yu
%-y%Q.;k?
%ec9`0^4S
public class SiteInfoBean { E\V-<]o
gWo`i
x~Egax
private String sSiteURL; //Site's URL g0m6D:f
private String sFilePath; //Saved File's Path Th&* d;
private String sFileName; //Saved File's Name aI$D qnF4
private int nSplitter; //Count of Splited Downloading File l[EnFbD6
U2*g9Es
?*}^xXI/
public SiteInfoBean() LFsrqdzJ
{//nSplitter的缺省值为5 U!E
//default value of nSplitter is 5 (vCMff/ Y1
this("","","",5); stDrF1{
} fUh7PF%
xkIRI1*!
x.rOP_rs
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (R_#lRaQ
{ &TqY\l
sSiteURL= sURL; $]4>;gTL'
sFilePath = sPath; &UhI1mi]h
sFileName = sName; @J~n$^ke
this.nSplitter = nSpiltter; _pSCv:3T
J`U\3:b`SP
X|'EyZ
} 3PB#m.N<
bWN%dn$$M
,EyZ2`|
public String getSSiteURL() #rL%K3'
{ KdT1Nb=
return sSiteURL; 9o<}*L
} sd;J(<Ofh
&Q>)3]|p
GY@-}p~it
public void setSSiteURL(String value) ;b=3iT-2"
{ 8}/v[8p
sSiteURL = value; E5d?toZ,8"
} *u$MqN
cd8~y
<}~`YU>=v
public String getSFilePath() !`8WNY?K
{ #}50oWE
return sFilePath; K1rF;7Y6
} ;=IC.<Q<}
$d1+d;Mn
=VMV^[&>
public void setSFilePath(String value) Oj<.3U[C
{ 8+no>%L
sFilePath = value; h_K(8{1
} 49%qBO$R
Nf0'>`/
%vjLw`
public String getSFileName() Mg H,"G
{ (?SK< 4!
return sFileName; !r:X`~\a
} t.sbfLu
=`f6@4H
Y>KRI2](<
public void setSFileName(String value) ]C|Zs=5
{ ng]jpdeA
sFileName = value; MWv_BXQ
} s#,~Zb=
[h "*>J{
d52l)8
public int getNSplitter() UGuEZ-r
{ V[f-Nj Kf
return nSplitter; +u%^YBr
} UUy%:t
n:zoN2lC
)i&z!|/2
public void setNSplitter(int nCount) e0O2>w
{ Z%3]
nSplitter = nCount; Ekx3GM_]
} o]0v#2l'
} _6a+" p
K~"J<798{
ncg5%(2
/* (Dr g
**Utility.java IUco 8
*/ Nx~9Ug
package NetFox; NET?Ep
JcsJfTI
(lwrk(
public class Utility { <rUH\z5cP
QUL^]6$
@OOnO+g
public Utility() %} WSw~X
{ y2k'^zE
jU2Dpxkt
%Gp%l
} JzD Mx?
W:q79u yX
//线程睡眠 ;Ee!vqD2
public static void sleep(int nSecond) Jy)E!{#x
{ J+f .r|?
try{ uGm~ Oo
Thread.sleep(nSecond); %4#,y(dO
} _{CMWo"l
catch(Exception e) m1x7f%_
{ ,lX5-1H
e.printStackTrace (); cjzhuH/y
} zx"'WM*
} O$jj&
/C(lQs*l
//日志 zoXCMBg[
public static void log(String sMsg) h&eu}aF
{ x\t)uM%
System.err.println(sMsg); r\7F}ZW/
} =[%ge{,t
:USN`"
1@Dp<Q
public static void log(int sMsg) 3V:{_~~
{ 44bTx y
System.err.println(sMsg); }qy,/<R
} ~m^.&mv3/
} ~ZeF5
(9:MIP
6@pPaq6
/* Rd6? ,
**TestMethod.java J2cqnwUV
*/ Wz)O,X^
package NetFox; 0yW#).D^b
n:JWu0,h
fl| 8#\r
public class TestMethod { m1@ste;$W
dz fR ^Gv
TWF6YAQm
public TestMethod() RAMkTS
{ ///xx/weblogic60b2_win.exe ^lVZW8
try{ @y%4BU&>0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Uc,D&Og
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6^U8Utx
SiteFileFetch fileFetch = new SiteFileFetch(bean); _DPWp,k<~
fileFetch.start(); ylm*a74-X
} Oo'IeXQ9(
catch(Exception e){e.printStackTrace ();} Y<('G5A
6<sd6SM
pvL)BD
} E$5)]<p! <
>ZMB}pt`
4;anoqiG\
public static void main(String[] args) M@$}Og
{ /DOV/>@5%
new TestMethod(); &u5OL?>
} hE>ux"_2/
} y<7C!E#b8
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