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)); r&0v,WSp&S
} ,":ADO-
for(int i=0;i<nEndPos.length-1;i++) eXnMS!g%Z
{ 7 -gt V#
nEndPos = nStartPos[i+1]; S`K8e^]
} =B*,S#r
nEndPos[nEndPos.length-1] = nFileLength; jFw?Ky2
} M,e_=aq
} >8t3a-/
DB:Ia5|*i
.cQwjL
//启动子线程 kxWf1hIz0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "J,ErnM
for(int i=0;i<nStartPos.length;i++) $oq&uL
{ #p*{p)]HiA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z^{VqC*o+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H1 n`A#6?
nStartPos,nEndPos,i); MCe=RR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KSqWq:W+
fileSplitterFetch.start(); Z)|*mJ
} E$4\Yc)(AL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F_zs"ex/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w80g)4V+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +aEE(u6%E@
nEndPos = " + nFileLength); $}aLFb
// fileSplitterFetch[nPos.length-1].start(); ZR6KE_
P`Anf_
j?g{*M
//等待子线程结束 r?\hZ*|M
//int count = 0; ,X+mXtg.
//是否结束while循环 [US.n+G6
boolean breakWhile = false; !R[o6V5T
HMS9_#[kE
jToA"udW/
while(!bStop) PD:" SfV,G
{ $vTU|o>|
write_nPos(); or]8;eQ?
Utility.sleep(500); bMxzJRrNg
breakWhile = true; CcLP/
d; oaG (e
tlCgW)<?
for(int i=0;i<nStartPos.length;i++) fN?HF'7V
{ y_Bmd
if(!fileSplitterFetch.bDownOver) w~;1R\?|
{ %=]~5a9
breakWhile = false; Cc]t*;nU_
break; g.s~Ph-G
} o D*h@yL
} 71@V|$Dy
if(breakWhile) +smPR
break; ^$6EO)<
tegLGp@_
RnIL>Akp
//count++; n>+M4Zb
//if(count>4) *t3fbD
// siteStop(); 2J|Wbey
} _Sosw|A
}Rt?p8p
=sG C
System.err.println("文件下载结束！"); B7fURL Rqr
} Qg%B<3 <
catch(Exception e){e.printStackTrace ();} Mf<Pms\F
} |jU/R
egYJ.ZzF0
b=wc-nA
//获得文件长度 rMH\;\ I|U
public long getFileSize() -Z-|49I/mN
{ &+xNR2";
int nFileLength = -1; va:5pvt2&
try{ ss-{l+Z5
URL url = new URL(siteInfoBean.getSSiteURL()); "/S-+Ufn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2pQ zT
httpConnection.setRequestProperty("User-Agent","NetFox"); 38tRb"3zP
dK#:io[Nz
HKP<=<8/O
int responseCode=httpConnection.getResponseCode(); xeIt7b?#
if(responseCode>=400) Elom_
{ ~Z=Q+'Hu0
processErrorCode(responseCode); Z7V1e<E
return -2; //-2 represent access is error %S. _3`A
} <2fZYt vt
%{Kp#R5E
.Qyq*6T3&
String sHeader; :Z- =1b~
uv%T0JA/
7s4G|N[wR\
for(int i=1;;i++) ?rKewdGY
{ ,j:`yB]4,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0/6f9A
//Utility.log(in.readLine()); yrSmI)&%
sHeader=httpConnection.getHeaderFieldKey(i); Q=)$
if(sHeader!=null) fk<0~tE
{ 9G[!"eZ}
if(sHeader.equals("Content-Length")) U6t>UE6k
{ {dH87 nt
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u<!8dQ8
break; 4[44Eku\
} 9f\Lon4lX
} _U?
else DJdW$S7
break; yTm/P!1S
} 2`9e20
} 7v]>ID
catch(IOException e){e.printStackTrace ();} %c<e`P;
catch(Exception e){e.printStackTrace ();} h8&VaJ
\uQ yp*P1s
)[C]1N=tK
Utility.log(nFileLength); FO<PMK
H9?(5
J/mLmSx
return nFileLength; b}HLuX
} )\s{\u \
-|bnvPmE
M4w,J2_8MK
//保存下载信息（文件指针位置） F{WV}o=MY
private void write_nPos() r5M {*
{ }^+E S^~
try{ <~@}r\
output = new DataOutputStream(new FileOutputStream(tmpFile)); LUc!a4i"fO
output.writeInt(nStartPos.length); Za_w@o
for(int i=0;i<nStartPos.length;i++) CBN,~wzP*
{ ,bzE`6
// output.writeLong(nPos); 84j6.\,
output.writeLong(fileSplitterFetch.nStartPos); pX8TzmIB0
output.writeLong(fileSplitterFetch.nEndPos); H*51GxK
} RZoSP(6
output.close(); aZn]8jC%
} K~$A2b95
catch(IOException e){e.printStackTrace ();} mM0VUSy
catch(Exception e){e.printStackTrace ();} -+?ZJ^A
} OyH>N/
G8z.JX-7g
"m,)3zND3
//读取保存的下载信息（文件指针位置） R&KFF'%
private void read_nPos() |(u6xPs;P
{ L{1MyR7`I+
try{ :d}I`)&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v7gs $'Q
int nCount = input.readInt(); /*Iq,"kGz
nStartPos = new long[nCount]; c|RTP
nEndPos = new long[nCount]; Of0(.-Q w
for(int i=0;i<nStartPos.length;i++) vX1 8 ]
{ B6ee\23
nStartPos = input.readLong(); h*d1G9%Q1
nEndPos = input.readLong(); KG<. s<
} =hFIH\x
input.close(); S9RH&/^H
} xl2;DFiYt
catch(IOException e){e.printStackTrace ();} 3w!8PPl
catch(Exception e){e.printStackTrace ();} 'tvX.aX2
} cQ}3? v
1i3;P/
v+d} _rCT
private void processErrorCode(int nErrorCode) 7"Qj(N
{ ZDny=&>#
System.err.println("Error Code : " + nErrorCode); K93L-K^J
} %4'<0
qJ(XW N H
yUnNf 2i
//停止文件下载 ?, B4
public void siteStop() K Q^CiX
{ F3nYMf
bStop = true; =sZ58xA
for(int i=0;i<nStartPos.length;i++) )hG4,0hv&
fileSplitterFetch.splitterStop(); .ni<'
!aQb Kp
AS4mJ UU9
} 4}4cA\B:n
} 8]h~jNku
//负责部分文件的抓取 5tx!LGOK
**FileSplitterFetch.java ":@\kw
*/ ~'1gX`o:
package NetFox; *!oV?N[eA'
Yo%ph%e
HpP82X xj
import java.io.*; &?g!)O
import java.net.*; ;P *`v
E<RPMd @a
fofYe0z
public class FileSplitterFetch extends Thread { ,="hI:*<
6a}
GHNw.<`l?
String sURL; //File URL }fO+b5U
long nStartPos; //File Snippet Start Position 2ieyU5q7#
long nEndPos; //File Snippet End Position @cB7tY*Ski
int nThreadID; //Thread's ID w.VjGPp
boolean bDownOver = false; //Downing is over QL]e<2oPJ
boolean bStop = false; //Stop identical jQBL8<
FileAccessI fileAccessI = null; //File Access interface d!{]CZ"@
=xw+cs1,x
=j~BAS*"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >piVi[`
{ -\<\OV:c*
this.sURL = sURL; CS'LW;#[
this.nStartPos = nStart; 'VgEf:BS
this.nEndPos = nEnd; 2OVN9_D%
nThreadID = id; j+9;Rvt2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'uC=xG.*}
} W{m_yEOf
mF:Pplf<
=U7P\sw2
public void run() %u}#|+8}
{ 60TM!\
while(nStartPos < nEndPos && !bStop) <$(y6+lY
{ }1 ,\*)5
]sTbEw.[
\&_pI2X
try{ po\(O8#5U
URL url = new URL(sURL); `=V p 0tPI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k?Kt*T
httpConnection.setRequestProperty("User-Agent","NetFox"); 7Q^p|;~a
String sProperty = "bytes="+nStartPos+"-"; D%}rQ,*
httpConnection.setRequestProperty("RANGE",sProperty); t!-\:8n
Utility.log(sProperty); {oSdVRI
Nj;5iy
nuH=pIq6x
InputStream input = httpConnection.getInputStream(); 6(=B`Z}a
//logResponseHead(httpConnection); fUMjLA|*I<
}W)b
Jxf>!\:AZu
byte[] b = new byte[1024]; Vy=P*
int nRead; 3n,jrX75u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cO$xT;kK
{ |k$6"dXSO
nStartPos += fileAccessI.write(b,0,nRead); P!Brw72
//if(nThreadID == 1) )SZzA'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QLH!>9Ch
} !RP0W
en>n\;U
> ^=n|%
Utility.log("Thread " + nThreadID + " is over!"); ~R&rQJJeJ
bDownOver = true; q68CU~i*
//nPos = fileAccessI.write (b,0,nRead); JC0#pU;
} {]bmecz
catch(Exception e){e.printStackTrace ();} Y'{}L@"t
} tD*k
} )T6:@n^]h
%QG3~b% h
uK]-m
//打印回应的头信息 5dGfO:Dy_
public void logResponseHead(HttpURLConnection con) <2d)4@B=
{ Pbd[gKX_
for(int i=1;;i++) _@i-?Q
{ *I!R0;HT
String header=con.getHeaderFieldKey(i); }uNj#Uf
if(header!=null) mqHcD8X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wPEK5=\4Ob
Utility.log(header+" : "+con.getHeaderField(header)); mv>0j<C91
else mPU}]1*p
break; Zs(BViTb|
} IsmZEVuC
} hraR:l D
eR4ib-nS
:zX^H9'E<(
public void splitterStop() A!,c@Kv 3
{ zMRa<G7
bStop = true; N5{v;~Cm}V
} tm/=Oc1p
Tdade+
veuX/>!
} Ni8%K6]z
(/At+MF3E
^vxx]Hji
/* BTD_j&+(
**FileAccess.java EnGh&]
*//文件访问(定位，写) &\I<j\F2/
package NetFox; m.rV1#AI
import java.io.*; i}:hmy'
'<3h8\"
Z^]jy>dj
public class FileAccessI implements Serializable{ 'z^'+}iyv
#8sy QWlG
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >|, <9z`D
RandomAccessFile oSavedFile; ~;jgl_5?b
long nPos; vp2w^/])u
}]H7uC!t
~r?tFE*+
public FileAccessI() throws IOException KTt+}-vP^
{ !zt>& t
this("",0); r&Nh>6<&/
} (V&8 WN
k>F!S`a&m
2Y%7.YX"
public FileAccessI(String sName,long nPos) throws IOException lX%-oRQ/os
{ sVr|kvn2
oSavedFile = new RandomAccessFile(sName,"rw"); KAXjvZN1
this.nPos = nPos; t #Kucde
oSavedFile.seek(nPos); KB^8Z@(+
} F53 .g/[
g0"xG}d
iZ>P>x\
public synchronized int write(byte[] b,int nStart,int nLen) n-2!<`UFX
{ U#[T!E
int n = -1; [<5/s$,i
try{ yZ7)|j
oSavedFile.write(b,nStart,nLen); Vpp$yM&?
n = nLen; dH.Fb/7f
} G62;p#
catch(IOException e) >?OUs>}3y2
{ T u%XhXl:j
e.printStackTrace (); &"WgO!pzD
} >]anTF`d
nBd]rak'
w>\oz
return n; j94~cYV
} O'B3sy
+,,dsL
xOPQ~J|z
} ;~DrsQb
y\j[\UZKO
G~DHNO6
/* ~Er0$+q=Y;
**SiteInfoBean.java [T4{K&
*/ JBA{i45x
package NetFox; xv Xci W
8\9W:D@"x
kssRwe%>;
public class SiteInfoBean { u$[&'D6
lAA&#-#YG
Ip`1Wv_
private String sSiteURL; //Site's URL 5x|$q kI
private String sFilePath; //Saved File's Path ?]bx]Y;
private String sFileName; //Saved File's Name /s%-c!o^
private int nSplitter; //Count of Splited Downloading File )X," NJG
-W.-m2:1
3 ^x&G?)
public SiteInfoBean() ern\QAhXX
{//nSplitter的缺省值为5 sVFX(yx0
//default value of nSplitter is 5 Xs|d#WbX
this("","","",5); L~e0^X?
} \D'mo
</ "Wh4>C
N%'(8%;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [kpQ:'P3
{ >r C*.
sSiteURL= sURL; 6W
sFilePath = sPath; 88<d<)7t
sFileName = sName; yPT o,,ca=
this.nSplitter = nSpiltter; 5D=U.UdR
]@cI_n
ZvQZD=,F
} %).I&)i
AX&Emz-
GIkeZV{4}
public String getSSiteURL() Ct?xTFb
{ >Ik%_:CC`
return sSiteURL; _-H,S)kI`
} ]K8G}|Wy6
-hfkF+=U'
suIYfjh
public void setSSiteURL(String value) o<p4r}*AVJ
{ %-fS:~$
sSiteURL = value; p %.Adxx
} p<h(
bC"h7$3
Ac{TqiIv
public String getSFilePath() ^b~ZOg[p
{ )(yaX
return sFilePath; -IVWkA)7
} _1O .{O
mJd8?d
^fsC]9NS
public void setSFilePath(String value) nv+miyvvm
{ 9@lG{9id?
sFilePath = value; nj00g>:>
} b?cO+PY01
G9xO>Xp^Al
ZwY mR=
public String getSFileName() yK9EHJ$
{ E_$nsM8?
return sFileName; ~ArRD-_t
} a%a0/!U[
>dgq2ok!u
zsd<0^ p\{
public void setSFileName(String value) 7&HcrkP]
{ Wl=yxJu_(
sFileName = value; TG8U=9qt
} vfj{j= G
<h+@;/v:
jA2%kX\6//
public int getNSplitter() tI^[|@,
{ pRxVsOb
return nSplitter; ~*\ *8U@7
} "Xwsu8~
G(shZ=fq
3G 5xIr6
public void setNSplitter(int nCount) (RrC<5"
{ D+ .vg?8
nSplitter = nCount; ?IS[2 v$
} +_vf=d
} =zrfh-lwH
@c"s6h&
{*g{9`
/* P_mP ^L
**Utility.java @p/"]zf
*/ 3}3b@:<
package NetFox; 4bdCbI
EBk-qd a}
B<Cg_C
public class Utility { y4 ]5z/
Y=_*Ai
v@2@9/
public Utility() $_eJ@L#
{ 9C Ki$L
yA*U^:%
Wlq3r#
} :i {; 81V
_akjgwu
//线程睡眠 `D=d!!1eUi
public static void sleep(int nSecond) L:?Ew9Lf
{ *}Gys/\!S
try{ +O8zVWr
Thread.sleep(nSecond); c3c3T`B
} cH:&S=>h
catch(Exception e) 'L9hM.+
{ #4"eQ*.*"
e.printStackTrace (); SD8>,
} 1gt 7My
} xI#rnx*
D^p)`*
//日志 Ly2!(,FB.
public static void log(String sMsg) 0yMHU[):~
{ FzCXA=m
System.err.println(sMsg); }y J,&N'p
} p0l.f`B
7i02M~*uS
S5Pn6'w
public static void log(int sMsg) hcYqiM@8>
{ ''!j:49
System.err.println(sMsg); 4f~q$Sf]<
} saQo]6#
} !Z{7X ^
dNqj|Vu
*u,xBC2C
/* -'WR9M?fq
**TestMethod.java [TqX"@4NS
*/ ,VUOsNN4\
package NetFox; -?{g{6
xdaq` ^Bbt
QG L~??
public class TestMethod { x{So
$$Ibr]$5
T?jN/}qg
public TestMethod() v6! `H
{ ///xx/weblogic60b2_win.exe 9asA-'fZ
try{ d>#X+;-k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s,/C^E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `jhbKgR[
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~+Cl9:4T
fileFetch.start(); rTJqw@]#WH
} H+gB|
catch(Exception e){e.printStackTrace ();} T-7(3#&
k{lXK\zN
j':<7n/A
} Pd `~#!
xH,e$t#@@~
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public static void main(String[] args) Y<N#{)Q
{ Kg /,
new TestMethod(); IC$"\7 @
} _PwPLSg
} 9q&~!>lt
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