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)); .T#h5[S2x
} bM+}j+0
for(int i=0;i<nEndPos.length-1;i++) <My4)3
{ 1-.6psE
nEndPos = nStartPos[i+1]; D!^&*Ia?2
} :Z3Tyj}4
nEndPos[nEndPos.length-1] = nFileLength; L9W'TvTwo
} lpvZ[^G
} o]u,<bM$
tHgu#k0
$~W=)f9
//启动子线程 WzDL(~m+Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =c8xg/
for(int i=0;i<nStartPos.length;i++) }(FF^Mh
{ S ( e]@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DI"KH)XD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ckykRqk}
nStartPos,nEndPos,i); $3psSQQo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 14Y_ oH9
fileSplitterFetch.start(); {(Jbgsxm
} r01Z 0>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !Z]#1"A8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lkl+o&D9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", td@I ;d2
nEndPos = " + nFileLength); /Ps/m!
// fileSplitterFetch[nPos.length-1].start(); -Ri/I4Xj
ObnQ,x(
(#KSwWo{ed
//等待子线程结束 (JenTL`%u
//int count = 0; z_nv|5"
//是否结束while循环 |Y"nZK,
boolean breakWhile = false; %k3A`ClW
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f=:ycd!
while(!bStop) "Tt5cqUQoY
{ PuO5@SP~
write_nPos(); w5Lev}Rb
Utility.sleep(500); ?DJ/Yw>>3
breakWhile = true; OYW:I1K<5
&UrPb%=2H
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for(int i=0;i<nStartPos.length;i++) S*PcK>
{ bAOL<0RS9`
if(!fileSplitterFetch.bDownOver) @-zL"%%dw'
{ N_L~oX_
breakWhile = false; _Fe%Ek1Yy
break; wB'GV1|jL
} 'rl?'~={p
} e\)r"!?H`
if(breakWhile) -A1@a=q
break; aNUU' [
8/gA]I 6=#
AdU0 sZ+&c
//count++; _"l2UDx
//if(count>4) f^Io:V\
// siteStop(); t9l]ie{"o.
} $Iz*W]B!
9t8NK{
@3*S:;x
System.err.println("文件下载结束！"); -qyhg-k6
} G'#Uzwo
catch(Exception e){e.printStackTrace ();} db*yA@2Lg
} U\y:\+e l
ly9tI-E
;}B6`v
//获得文件长度 S/,)X
public long getFileSize() ?*AhGza/
{ 6K7DZ96L
int nFileLength = -1; unvS`>)Np
try{ >p*7)
URL url = new URL(siteInfoBean.getSSiteURL()); 5FMe&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xyzYY}PS
httpConnection.setRequestProperty("User-Agent","NetFox"); 2p %j@O
M!tR>NMH
_~Id~b
int responseCode=httpConnection.getResponseCode(); GHWt3K:*w
if(responseCode>=400) @b&_xT
{ um,G^R
processErrorCode(responseCode); ]621Z1
return -2; //-2 represent access is error 4$oDq
} TTagZI$
P(xgIMc H
Se}&2 R
String sHeader; L/ g8@G ;
zFi)R }Ot
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for(int i=1;;i++) 4|/}~9/
{ 8hV>Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xp*Wf#BF
//Utility.log(in.readLine()); A1Es>NK[qW
sHeader=httpConnection.getHeaderFieldKey(i); XOL_vS24
if(sHeader!=null) Suo%uD
{ PiIP%$72O
if(sHeader.equals("Content-Length")) ##6u
{ 7I/a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )">uI\bi
break; oM^VtH=>
} >PYc57S1c
} }D]y-BbA.
else * ,Le--t
break; "M3S
} A'aYH`j
} O03N$Jq A
catch(IOException e){e.printStackTrace ();} Nt,:`o |
catch(Exception e){e.printStackTrace ();} IOddu2.(
0" F\V
%bp'`B=
Utility.log(nFileLength); ^U9b)KA
HDi_|{2^
"cwvx8un
return nFileLength; MX"M2>"pT
} %RX!Pi}5+g
]T=o>%
h$]nfHi_Q
//保存下载信息（文件指针位置） Nd He::
private void write_nPos() /H*[~b
{ LFAefl\
try{ G%fXHAs.+
output = new DataOutputStream(new FileOutputStream(tmpFile)); g;~$xXn
output.writeInt(nStartPos.length); .U#oN_D
for(int i=0;i<nStartPos.length;i++) P>EG;u@.
{ cwE?+vB
// output.writeLong(nPos); [(; .D
output.writeLong(fileSplitterFetch.nStartPos); ]E|E4K6g
output.writeLong(fileSplitterFetch.nEndPos); q*!Vyk
} I6i qC"BK
output.close(); q{}U5(,{0
} ?aQVaw&L!7
catch(IOException e){e.printStackTrace ();} rRXF@
catch(Exception e){e.printStackTrace ();} -amNz.`[PR
} *JOp)e0b
)}J}d)
gm$<U9L\v
//读取保存的下载信息（文件指针位置） ;EsfHCi)
private void read_nPos() &`}d;r|yn1
{ yujv^2/
try{ A |P wm`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z(#CO<C.t
int nCount = input.readInt(); J;k8 a2$_
nStartPos = new long[nCount]; E J&w6),d
nEndPos = new long[nCount]; h ^Wm03w
for(int i=0;i<nStartPos.length;i++) )_kU,RvZ
{ m'KEN<)s
nStartPos = input.readLong(); ll ^I;o0
nEndPos = input.readLong(); RgD:"zeM
} XzW\p8D^u
input.close(); L*6>S_l[
} lvG+9e3+
catch(IOException e){e.printStackTrace ();} bSW~hyI w
catch(Exception e){e.printStackTrace ();} 8w ]'U
} 2]5ux!Lqln
|ADg#oX
Z*Fn2I4
private void processErrorCode(int nErrorCode) _=K\E0I.m
{ uyoV)
System.err.println("Error Code : " + nErrorCode); ;?{OX
} cS>xT cj
C_ W%]8u
f9HoQDFsM
//停止文件下载 n{!=gR.v.
public void siteStop() w x,gth*p
{ h$d`Jmaq
bStop = true; =&mdxKoT0
for(int i=0;i<nStartPos.length;i++) eI/@ut}v
fileSplitterFetch.splitterStop(); 'Uo|@tK
{3BWT
6n^vG/.M
} dW%;Z
} E8.1jCL>{"
//负责部分文件的抓取 o;v_vCLO
**FileSplitterFetch.java ~Efi|A/
*/ C}71SlN'M
package NetFox; %O*)'ni
Me-H'Mp~
xgIb4Y%
import java.io.*; eMjW^-RgE5
import java.net.*; lrmz'M'
v{) *P.E
<%"CQT6g%
public class FileSplitterFetch extends Thread { 8Ib5
~V/?/J$
: n\D
String sURL; //File URL #VuiY
long nStartPos; //File Snippet Start Position m,SWG[~
long nEndPos; //File Snippet End Position (wp?tMN5#
int nThreadID; //Thread's ID bKQ-PM&I/t
boolean bDownOver = false; //Downing is over fK4NmdTV
boolean bStop = false; //Stop identical \O\veB8
FileAccessI fileAccessI = null; //File Access interface FD.L{
4Z/]7Ie
|Gt]V`4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 30QQnMH3
{ #Qd"d3QG
this.sURL = sURL; Gu%}B@4^
this.nStartPos = nStart; TYedem<$
this.nEndPos = nEnd; {+ WI>3
nThreadID = id; 51puR8AG>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *KPNWY9!W
} << aAYkx<
{ pu .l4nk
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public void run() ZRYHsl{F+
{ 2w:cdAv$
while(nStartPos < nEndPos && !bStop) _'P!>C!
{ I z)~h>-F
$,jynRk7q
'Inqa;TQz
try{ ]ChN]>o
URL url = new URL(sURL); CQ#%v%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5x}OrfDU
httpConnection.setRequestProperty("User-Agent","NetFox"); vH vwH
String sProperty = "bytes="+nStartPos+"-"; Nk shJ2
httpConnection.setRequestProperty("RANGE",sProperty); %|3NCyJ*7
Utility.log(sProperty); z.*=3
Zc*gRC
^4tz*i
InputStream input = httpConnection.getInputStream(); ]|/\Sd
//logResponseHead(httpConnection); !Baq4V?KN
ysQ8==`38i
CfjVx
byte[] b = new byte[1024]; ~[ x}
int nRead; >=ng?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g/x\#W
{ G 4C 7
nStartPos += fileAccessI.write(b,0,nRead); i)+2?<]
//if(nThreadID == 1) +FYhDB~m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QfsTUAfR
} e[J0+ x#;r
8}Su7v1
}P"JP[#E\
Utility.log("Thread " + nThreadID + " is over!"); df!n.&\y!
bDownOver = true; X" ;ly0Mb
//nPos = fileAccessI.write (b,0,nRead); 44_CT?t<
} .p(~/MnO
catch(Exception e){e.printStackTrace ();} =j!Ruy1
} .{LJ
} 2~SjRIpUw
j!QP>AM|`
vq*)2.
//打印回应的头信息 }_o!fV
public void logResponseHead(HttpURLConnection con) `K\(I#z
{ H He~OxWg
for(int i=1;;i++) @|J+f5O
{ DmgWIede|:
String header=con.getHeaderFieldKey(i); 7I<];j
if(header!=null) U)grC8 C
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *dm?,~f%<
Utility.log(header+" : "+con.getHeaderField(header)); GHo=)NTjy
else t /CE,DQ
break; cdfvc0
} &l NHNu[
} q=h~zjQ?R
oyY0!w,Y
~85Pgb<
public void splitterStop() Yet!qmZ
{ \!,@pe_
bStop = true; aqAWaO
} 8k`rj;
ok7yFm1\
@}@J$ g
} I!sB$=n
-g]g
Um9]X@z
/* O8%Y .SK
**FileAccess.java >E`p@ e+
*//文件访问(定位，写) b_T?jCyW
package NetFox; GwaU7[6
import java.io.*; y!?l;xMS
DEkFmmw
wIT}>8o
public class FileAccessI implements Serializable{ ?4i:$.A Y
4#BoS9d2I<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'Nbae-pf
RandomAccessFile oSavedFile; O[[#\BL
long nPos; s`:-6{E
|4s`;4c&
+]%d'h
public FileAccessI() throws IOException 4_w+NI,;
{ &18CCp\3)c
this("",0); __,1;=
} 1k}U+
Z:PsQ~M
9V=bV=4:
public FileAccessI(String sName,long nPos) throws IOException j7)Xm,wI8
{ l[q%1-N
oSavedFile = new RandomAccessFile(sName,"rw"); $Z;?d@6yI
this.nPos = nPos; -Vi"hSsUP
oSavedFile.seek(nPos); @i[z4)"S
} `9
&k+'TcWm
}#/,nJm'
public synchronized int write(byte[] b,int nStart,int nLen) OyG$ ]C
{ FaNH+LPe
int n = -1; )MKzAAt~
try{ |*im$[g=-
oSavedFile.write(b,nStart,nLen); FN&.PdRT
n = nLen; ;@@1$mzK
} Et=N`k_gO
catch(IOException e) DM*mOT
{ I =t{ u;
e.printStackTrace (); ]&3UF?
} 4 }l,F
%<oey%ue
0.+"K}
return n; 9T4x1{mO
} *FkG32k
fL8+J]6A6
3+;}2x0-F
} byYdX'd.
tVZjtGz=
eyZ /%4'q
/* 7mSVL\\^
**SiteInfoBean.java Elt=/,v`!
*/ JBCcR,\kM*
package NetFox; f!~gfnn
=>Vo|LBoe
)POuH*j
public class SiteInfoBean { r[zxb0YA
&WIiw$@
GQTMQXn(
private String sSiteURL; //Site's URL .,pGW8Js
private String sFilePath; //Saved File's Path >ln%3=
private String sFileName; //Saved File's Name 9d4PH
private int nSplitter; //Count of Splited Downloading File dlC)&Ai
zLlu%Oc
M?4)U"_VE
public SiteInfoBean() t)LD-%F
{//nSplitter的缺省值为5 b]s*z<|%
//default value of nSplitter is 5 .N99=%[}h
this("","","",5); L{|V13?
} m9UI3fBX
_yyQ^M/
Gw*n,*pz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :0.Z/s -
{ adh=Kp e!w
sSiteURL= sURL; /a\6&Eb
sFilePath = sPath; yAoJ?<4^W
sFileName = sName; E8WOXoP(
this.nSplitter = nSpiltter; LoLmT7
8oG0tX3i
8H3|i7.1h
} @eN x:}
)eNR4nF
maLKUSgo
public String getSSiteURL() uYlC*z{
{ jRS0(8
return sSiteURL; 7z"xjA
} {T Z7>k
V+X>t7.Q
2JZf@x+}
public void setSSiteURL(String value) ;}{%|UAsx
{ V?v,q'? $
sSiteURL = value; C`3}7qi|C
} 2/qP:3)
"#2z 'J
S*6P=O*
public String getSFilePath() 1Tf"<Dp
{ pGz-5afL
return sFilePath; \~1M\gZP
} w: ~66 TCI
q_5k2'4K
716JnG>
public void setSFilePath(String value) IMjnj|Fj
{ QF(.fq8, U
sFilePath = value; |k:MXI
} Qj?+R F6(
[y|"iSD
_e$15qW+
public String getSFileName() 0&Q-y&$7
{ 3(':4Tas
return sFileName; U[=VW0
} n4+l,~
0.C y4sH'
_rXTHo7P
public void setSFileName(String value) Tm5]M$)
{ 9D:p~_"g
sFileName = value; }<o.VY&;.
} ziR}
|BnjT*_9
s_-G`xT>{
public int getNSplitter() $*^Ms>Pa_
{ R+FBCVU&TJ
return nSplitter; D(D:/L8T,
} Rz1&(_Ps
<\GP\G
2J =K\ L
public void setNSplitter(int nCount) LFob1HH*8
{ 9D++SU2:}
nSplitter = nCount; )f9f_^;
} X>j% y7v
} Oemi}
`:!mPNW#
~isrE;N1|
/* k/YEUC5
**Utility.java q?g4**C
*/ m'k.R j
package NetFox; yTwv2l;U
b[Sd$ACd
j2SJ4tB /
public class Utility { * F%Wf
EV| 6._Z(D
=4uL1[0'
public Utility() *Hy-D</w%
{ tM]~^U
pb1/HhRR^n
TaeN?jc5
} "Q6oPDX(
MZ o\1tU-i
//线程睡眠 XRCiv
public static void sleep(int nSecond) %4Cs c
{ c1M/:*?%
try{ L5!aLv#
Thread.sleep(nSecond); R9nW5f Nf
} -hw^3Af
catch(Exception e) }YWLXxb;
{ (:Rj:8{
e.printStackTrace (); AJt*48H*G
} :@{(^}N8u
} JsI`#
m07= _4
//日志 yKF"\^`@
public static void log(String sMsg) Yo3my>N&g
{ Cqy84!Z<
System.err.println(sMsg); p9Zi}!
} =#dW^?p
oBiJiPE=`
A#$oY{"2Y
public static void log(int sMsg) Y3+DTR0|'
{ iTF`sjL
System.err.println(sMsg); &2[OH}4
} Gs;wx_k^
} m`gH5vQa
e/JbRbZX
5xe}ljo
/* &?flH;
**TestMethod.java 3ha^NjE
*/ kx0(v1y3gT
package NetFox; S[(Tpk2_
|;e K5(|
H)z}6[`
public class TestMethod { 4Ra
2%UzCK
"C%<R
public TestMethod() xX$'u"dsA
{ ///xx/weblogic60b2_win.exe >Q#h,x~vu
try{ Wsya:9|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #'[4k:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =aZgq99
SiteFileFetch fileFetch = new SiteFileFetch(bean); t=o2:p6&
fileFetch.start(); l Os91+.%
} K8M[xaI@
catch(Exception e){e.printStackTrace ();} Y!s94#OaZ
jWk1FQte
=vJ:R[Ilw
} #v+2W
!m8MyZ}%
cB#5LXbCE
public static void main(String[] args) *P2_l Q=
{ 3gtQS3$4s
new TestMethod(); 1"tyxAo\
} Pj(DlC7G,
} ChzKwYDY
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