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)); Q .RO
} jMpa?Jp1
for(int i=0;i<nEndPos.length-1;i++) SN]LeXesS
{ #1Z7&#R/
nEndPos = nStartPos[i+1]; *v #/Y9}
} \aSz2lxEHn
nEndPos[nEndPos.length-1] = nFileLength; ZCiY,;c
} oKKz4
} )+~E8yK
9Vh_[^bR
.)PqN s:
//启动子线程 Z[IM<S9lz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e6P[c=m #
for(int i=0;i<nStartPos.length;i++) Rl@$xP
{ -zC]^Ho@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hLuJWjCV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), yFeeG3n3
nStartPos,nEndPos,i); $p6N|p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Gt^d;7x]
fileSplitterFetch.start(); pt!'v$G/*
} 3IyZunFT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Pz~q%J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kojG-M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r,'O).7
nEndPos = " + nFileLength); /7p>7q9g
// fileSplitterFetch[nPos.length-1].start(); *TnzkNN_,
nxRwWj57
8M93cyX
//等待子线程结束 F'BdQk3o
//int count = 0; CIQwl 6H9
//是否结束while循环 sJ6a7A8)
boolean breakWhile = false; {e9Y !oFg
~mA7pOHj
L+R>%d s
while(!bStop) vfbe$4mH
{ TA)LPBG
write_nPos(); k^*$^;z
Utility.sleep(500); 1X:&*a"5
breakWhile = true; h3 @s2 fK
p{C9`wi)
zD_HyGf
for(int i=0;i<nStartPos.length;i++) =~,l4g\
{ T|+$@o
if(!fileSplitterFetch.bDownOver) 5faj;I{%JY
{ ZLJNw0!=|t
breakWhile = false; qY}Cg0[@g
break; W78o*z[O
} wgZrrq/W|
} 3j&B(aLy
if(breakWhile) &7][@v
break; /co%:}ln
j`9Nwa
BTs0o&}e
//count++; "_)|8|gN
//if(count>4) `vEqj v
// siteStop(); b`]M|C [5
} *<dHqK`?C
u+DX$#-n!]
j |td,82.
System.err.println("文件下载结束！"); 5B|,S1b
} 2FT-}w0;
catch(Exception e){e.printStackTrace ();} AfE%a-;:
} b7v dk
B(Y.`L? %E
0BXs&i-TP5
//获得文件长度 ?pKN'`
public long getFileSize() Oxj(g;}
{ *H*\gaSh
int nFileLength = -1; F(0Z ]#+
try{ u_Zm1*'?B
URL url = new URL(siteInfoBean.getSSiteURL()); 85C#ja1&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5G oK"F0i
httpConnection.setRequestProperty("User-Agent","NetFox"); -mC:r&Y>[
^2JPyyZa
#S*pD?VZ
int responseCode=httpConnection.getResponseCode(); d5' )6
if(responseCode>=400) AA.Ys89V
{ x\]z j!
processErrorCode(responseCode); SJ[AiHR
return -2; //-2 represent access is error j!CU
} qZ?{-Vw
TK %<a/
%^U"Spv;
String sHeader; fp-m.d:|
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3.~h6r5-
for(int i=1;;i++) 9 P~d:'Ib
{ xH@'H?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tx)OJY
//Utility.log(in.readLine()); G{O\)gf
sHeader=httpConnection.getHeaderFieldKey(i); MC6)=0:KX
if(sHeader!=null) DUo0w f#D^
{ N*':U^/t4J
if(sHeader.equals("Content-Length")) wO!% q[
{ >F|qb*Tm7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d/4ubf+$k
break; )^(P@D.L
} 6d};|#}
} k%!VP=c4s
else v*XkWH5
break; uZ<%kV1B
} ,| <jjq)
} -[<vYxX:h:
catch(IOException e){e.printStackTrace ();} K+-zY[3
catch(Exception e){e.printStackTrace ();} F'ENq6
*LEu=3lp%>
bkkSIl+Q
Utility.log(nFileLength); _y"a2M
p4y6R4kyT
]p\u$VY9
return nFileLength; kMqD iJ
} _ flgQ
[xWEf#', !
!^]q0x
//保存下载信息（文件指针位置） Pm;I3r=R\
private void write_nPos() i<bxc
{ InP[yFV-z
try{ "B~WcC
output = new DataOutputStream(new FileOutputStream(tmpFile)); s9G)Bd 8
output.writeInt(nStartPos.length); 7^&lbzVbm(
for(int i=0;i<nStartPos.length;i++) Yu1QcFuy
{ ),MU+*`
// output.writeLong(nPos); 48:liR
output.writeLong(fileSplitterFetch.nStartPos); OCwW@OC +
output.writeLong(fileSplitterFetch.nEndPos); '1Y<RD>x
} Lp!0H `L
output.close(); 2'|XtSj
} CH55K[{<
catch(IOException e){e.printStackTrace ();} U{HyxZ|q<
catch(Exception e){e.printStackTrace ();} T\)dt?Tv#\
} %l%=Dkss
Y'2-yB
2.!1kije
//读取保存的下载信息（文件指针位置） %7iUlO}}V
private void read_nPos() vNPfUEnA
{ =A$Lgk>|
try{ GA(OK-WUd
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4P`PmQ=GQh
int nCount = input.readInt(); 8I<_w4fC
nStartPos = new long[nCount]; <=$rU232}
nEndPos = new long[nCount]; SgyqmYTvZw
for(int i=0;i<nStartPos.length;i++) 23)F-.C}j
{ D7EXqo
nStartPos = input.readLong(); ~Ry $>n*/
nEndPos = input.readLong(); B,r5kQI4
} }Q,(u
input.close(); rf)PAdj|~
} BN_!Y)Fl
catch(IOException e){e.printStackTrace ();} <zfO1~^
catch(Exception e){e.printStackTrace ();} =VCi8jDkP
} /]pX8 d
_RN/7\
) )fDOJ
private void processErrorCode(int nErrorCode) dko[
{ ZYrKG+fkl
System.err.println("Error Code : " + nErrorCode); XCW+ pUX
} ( P
Gs^(YGtU
6{cybD`Ef&
//停止文件下载 Bjurmo
public void siteStop() X@i+&Nv"<
{ rat=)n)"t
bStop = true; q2[+-B)m
for(int i=0;i<nStartPos.length;i++) BT&rp%NO6l
fileSplitterFetch.splitterStop(); zC<'fT/rG
M|1eqR%x-?
N5[_a/
} ~l;yr @
} (PRaiE
//负责部分文件的抓取 s4!|v`+$M
**FileSplitterFetch.java nrxjN(9V%+
*/ #&;m<%
package NetFox; E6,`Ld;c[
OJnPP>
-OHvK0~
import java.io.*; pI'8>_o
import java.net.*; ;5&k/CB1
QBg}2.
Wpiv1GZ%c8
public class FileSplitterFetch extends Thread { HR/k{"8W4Q
L#@l(8.
, LCH2r
String sURL; //File URL PpX{+^z-%
long nStartPos; //File Snippet Start Position L-^# 02
long nEndPos; //File Snippet End Position Bq~AU#
int nThreadID; //Thread's ID \W3+VG2cA
boolean bDownOver = false; //Downing is over 43UJ#rF
boolean bStop = false; //Stop identical 4U}.Skzq
FileAccessI fileAccessI = null; //File Access interface cRs{=RGc
c.|sW2/
8Uj68Jl?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dM);LT8@
{ 0S)"Q^6ny
this.sURL = sURL; Hj}g1"RA
this.nStartPos = nStart; MsN2A6|33
this.nEndPos = nEnd; Z\ "Kd
nThreadID = id; 3MS3O.0]/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j<. <S {
} 7AZ5%o
6Y0/i,d*
`XQx$I
public void run() e["Z!D_H
{ @c.11nfn`
while(nStartPos < nEndPos && !bStop) , V0iMq
{ ` 4s#5g
>=Rd3dgDG
&-EyM*:u!
try{ B`'}&6jr.
URL url = new URL(sURL); T>AI0R3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m)tI
httpConnection.setRequestProperty("User-Agent","NetFox"); `R4W4h'I
String sProperty = "bytes="+nStartPos+"-"; =RCfibT!C
httpConnection.setRequestProperty("RANGE",sProperty); ;/6:lL
Utility.log(sProperty); {,nd_3"Vq
|THkS@Br
@j)f(Zlu#
InputStream input = httpConnection.getInputStream(); /NPl2\o.
//logResponseHead(httpConnection); >tE,8
E-*>f"<h
*g/I&'^
byte[] b = new byte[1024]; ND)M3qp2(
int nRead; I(iGs I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) K-g=td/@
{ &;uGIk>s
nStartPos += fileAccessI.write(b,0,nRead); baO&n
//if(nThreadID == 1) VNOK>+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VfJX<e=k
} J.CZR[XF#
zD#+[XI]K
XY$cx~
Utility.log("Thread " + nThreadID + " is over!"); =6"hj,[Q
bDownOver = true; ynOc~TN
//nPos = fileAccessI.write (b,0,nRead); il`C,CD
} +E""8kW- Z
catch(Exception e){e.printStackTrace ();} Z(Ls#hp
} Px^<2Q%Fs
} Yc|-sEK/
A61-AwvF8-
*`\4j*$^
//打印回应的头信息 L@^!(
public void logResponseHead(HttpURLConnection con) -Y!=Iw 4
{ 7@e[:>e
for(int i=1;;i++) U3VsMV*Y
{ N?`GZ+5
String header=con.getHeaderFieldKey(i); 6i?kkULBS
if(header!=null) 52q!zx E
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q(${jz4w
Utility.log(header+" : "+con.getHeaderField(header)); Ay[9k=q]
else [\w>{
break; `qYc#_ELv
} xr1I8 5kM
} 6P/9Vh j'
k^vmRe<lk
+(=[M]5#n
public void splitterStop() @/ovdf{
{ [3bwbfHhi
bStop = true; QtO[g
} M\$<g
}!J/ 9WKgU
|~T+f&
} (t]R#2{
JqH.QnKcv
u0$5Fd&X
/* Hf E;$
**FileAccess.java ;*85'WcS
*//文件访问(定位，写) =fu_ Jau}
package NetFox; 0^-b}
import java.io.*; (HP={MrV
"p_[A
mSvTnd8
public class FileAccessI implements Serializable{ -^SD6l$
EzY scX.[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fh5^Gd~
RandomAccessFile oSavedFile; s*A|9uf5
long nPos; jak|LOp
"MVN/Gl
DQHGq_unP
public FileAccessI() throws IOException GQc%OQc\
{ #7E&16Fk
this("",0); H6+st`{
} BRQ5
Yh!\:9@(
;-P:$zw9c
public FileAccessI(String sName,long nPos) throws IOException M. UUA?d<'
{ vA $BBXX
oSavedFile = new RandomAccessFile(sName,"rw"); D\i8rqU/l
this.nPos = nPos; N'1[t
oSavedFile.seek(nPos); ,'@ISCK^
} '\3.isTsx
DW;.R<8
J1wGK|F~
public synchronized int write(byte[] b,int nStart,int nLen) %>QSeX
{ e[Ul"pMvS`
int n = -1; l=.InSuLT
try{ UW~tS
oSavedFile.write(b,nStart,nLen); JO;`Kz_$
n = nLen; U1@P/
} d`rDEa
catch(IOException e) s?gXp{O?X
{ +r34\mAO
e.printStackTrace (); i=+<7]Q
} 9=;g4I
9HBx[2&
k@X As
return n; [O =)FiY-
} Ql!6I(
JZ*?1S>
,@j&q
} ), x3tTR
=I*ZOE3n
B?>#cpWj
/* 3jQ$72_
**SiteInfoBean.java @C6DOB
*/ ?%TM7Z4
package NetFox; - &LZle&M
I5 7<0
[AK%~Kg9
public class SiteInfoBean { Lzb [%?
DL/*t.)"et
>!WBlSy
private String sSiteURL; //Site's URL !EC\1rmdlN
private String sFilePath; //Saved File's Path '[M2Q"X
private String sFileName; //Saved File's Name xo@/k
private int nSplitter; //Count of Splited Downloading File {hp@j#
S+=@d\S}"
D"><S<C\C
public SiteInfoBean() &rE l
{//nSplitter的缺省值为5 >5Rw~
//default value of nSplitter is 5 Bk(XJAjY
this("","","",5); dXy"yQ>{
} &ppZRdq]
Pn){xfqDl
qQ\hUii
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZtZV:re=
{ Ib<+m%Ac
sSiteURL= sURL; *v-xC5L1\
sFilePath = sPath; E;*TRr><
sFileName = sName; $+yQ48Wq
this.nSplitter = nSpiltter; 3xR#,22:}
H<3b+Sg
k{$"-3ed
} %1l80Z
st^N QL
UVi/Be#|
public String getSSiteURL() 9(\N+
{ I;PO$T
return sSiteURL; d3hTz@JY
} BwA~*5TFu
<i@jD
fpC@3itI
public void setSSiteURL(String value) v8M#%QoA
{ m(Xr5hw:6
sSiteURL = value; &_TjRj"
} Q#AHEm{9;s
M(gWd8?#
)Syf5I
public String getSFilePath() G\+MT(&5
{ [1X5r<(W5
return sFilePath; Cl){sP=8W
} (B4A$t
N`:bvr
`9NnL.w!
public void setSFilePath(String value) I ywx1ac
{ GOgT(.5
sFilePath = value; ]t0S_UH$
} J:!Gf^/)
X Ow^"=Oa[
MPw7!G(qj
public String getSFileName() zb*4Nsda:
{ FO3*[O
return sFileName; n]g,)m
} i2c<q0u
_A~gqOe
E^ti!4{<
public void setSFileName(String value) \?IwR]@y
{ \Xp"I5
sFileName = value; 8xz7S
} J#5o
s:.XF|e{
qOanu
public int getNSplitter() {;~iq
{ '%7]xp
return nSplitter; {Z;GNMO:
} jCa;g{#@
a#j^gu$m
xJ.!Q)[
public void setNSplitter(int nCount) q/G5aO*
{ CzbNG^+
nSplitter = nCount; +u)$o
} PA[Rhoit,
} OlFn<:V K
jv^L~<u
.DsYR/
/* ^aMdbB
**Utility.java ~n\ea:.
*/ -L3RzX
package NetFox; ^@> Qiy
+Ea XS
(pg9cM]NA
public class Utility { =l9#/G#R
CT`X~y10
32/P(-
public Utility() cW%O-
{ jg/<"/E
.k(_j.v
md s\~l73
} nJ@hzK.
{bEEQCweNJ
//线程睡眠 | Ylk`<
public static void sleep(int nSecond) ZJm^znpw6
{ "xI[4~'`:
try{ ,6L>f.V^(U
Thread.sleep(nSecond); |g!# \
} ~(S4/d5
catch(Exception e) G-<~I#k
{ aC` c^'5
e.printStackTrace (); vRs5-T
} m$g^On
} C_)>VPD
iB-s*b<`~
//日志 K>eG5tt
public static void log(String sMsg) #+\G- =-
{ 9mm(?O~'p
System.err.println(sMsg); `7ZJB$7D|*
} '& :"/4@)
gV;GC{pY
u&bU !ZI
public static void log(int sMsg) tsD^8~ t|h
{ 55\mQ|.Jn
System.err.println(sMsg); .@V>p6MV
} B:.rp.1
} aQFHB!
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-GjJrYOU
/* S\(_"xJPp
**TestMethod.java N|}`p"
*/ 7 >(ygu
package NetFox; sxtGl^,mU:
1L7,x @w
5K<C
public class TestMethod { z(qz(`eGC&
?CDq^)T[
q4oZJ-`
public TestMethod() nt6"}vO
{ ///xx/weblogic60b2_win.exe @d|9(,Q
try{ N5DS-gv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f6)H!SI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f_8~b0`
SiteFileFetch fileFetch = new SiteFileFetch(bean); AtI,&S#{
fileFetch.start(); {VG6m Hw
} R2@u[
catch(Exception e){e.printStackTrace ();} a6_`V;
'iK0Wr
uip]K{/A!e
} rg\w!L(
Dl{Pd`D
,d#4Ib
public static void main(String[] args) cALs;)z
{ %s>E@[s
new TestMethod(); /Z_QCj
} 75f.^4/%
} "?SnA +)
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