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)); rG6G~|mS
} irD5;xk([
for(int i=0;i<nEndPos.length-1;i++) K_YOp1
{ [. 9[?8
nEndPos = nStartPos[i+1]; ?..BA&zRk
} o}114X4q;
nEndPos[nEndPos.length-1] = nFileLength; Z;81"
} &`v?oN9$
} UAhWJ$(C
Fc5t,P
8\{z>y
//启动子线程 F[Mwd &P@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fxPg"R!1i
for(int i=0;i<nStartPos.length;i++) 2{63:f1c`'
{ 0jlM~H
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n.2:fk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8I/3T
nStartPos,nEndPos,i); +71<B>L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qc @cdi
fileSplitterFetch.start(); ./k7""4
} wCNn/%C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I ]ZZN6"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *YeQCt-l
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jBYvOy*$Q
nEndPos = " + nFileLength); S\8v)|Pr
// fileSplitterFetch[nPos.length-1].start(); eN,9N]K
ga%\n!S
2vjkThh`I
//等待子线程结束 ?#=xx.cF
//int count = 0; .waw=C
//是否结束while循环 'Tjvq%ks
boolean breakWhile = false; "nu]3zcd
sb{K%xi%
O%\cRn8m
while(!bStop) zvdut ,6<
{ [m0X kvd
write_nPos(); 3< ?+Yhq
Utility.sleep(500); >bf.T7wy
breakWhile = true; U_5`
%5gdLm!p
MmjZq
for(int i=0;i<nStartPos.length;i++) lxL.ztL
{ ^%9oeT{
if(!fileSplitterFetch.bDownOver) ?QT6q]|d0+
{ w/m@(EBK
breakWhile = false; '?veMX
break; N:| :L:<1
} ~h3G}EH
} ?<!qF:r:
if(breakWhile) Uw.')ZY=
break; Z5 IWoY
bKCE;Wu:G
b`#YJpA
//count++; y ;[~(Yg[
//if(count>4) js81@WX!c
// siteStop(); H u;"TG
} 3tTOs
z:#]P0
CLaQE{
System.err.println("文件下载结束！"); 05FGfnq.8
} S"h;u=5it
catch(Exception e){e.printStackTrace ();} r$={_M$
} bLai@mL&a
e`qrafa
V'XEz;Ze
//获得文件长度 ?^%[*OCCC!
public long getFileSize() "frZ%mv
{ x'`{#bKD
int nFileLength = -1; gE2(E0H
try{ cWkg.ri-x
URL url = new URL(siteInfoBean.getSSiteURL()); 1WMZ$vsQUb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jDY B*Y^F
httpConnection.setRequestProperty("User-Agent","NetFox"); fAULuF
-`k>(\Q<d
9BtGzI\
int responseCode=httpConnection.getResponseCode(); F5Xb_&
if(responseCode>=400) TI7$J#
{ )_jboaNzwI
processErrorCode(responseCode); _:m70%i
return -2; //-2 represent access is error FQ<x(&/NF
} Vpnk>GWD
h(/? 81:
PF`uwx@zH
String sHeader; ZR}v_]l^
eA!Z7 '
cpa" ,8
for(int i=1;;i++) '\#q7YjaL
{ +x 3x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gLv+L]BnhH
//Utility.log(in.readLine()); |KYl'"5\
sHeader=httpConnection.getHeaderFieldKey(i); kzZgNv#G;
if(sHeader!=null) :.+w'SEn4M
{ {:gx*4}q8
if(sHeader.equals("Content-Length")) HqWWWCWal
{ #AGO~#aK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S!8<|WO^t
break; uBbQJvL
} 4P3RRS
} Pw<?Dw]m
else h.vy SwF"j
break; uy<3B>3~.
} utZI'5i
} ;-u]@35
catch(IOException e){e.printStackTrace ();} Mgw#4LU
catch(Exception e){e.printStackTrace ();} 89&9VX^A
C|&tdh :g
2X2Ax~d@
Utility.log(nFileLength); ;O hQBAC
8?nn4]P
]20:8l'
return nFileLength; M +OVqTsFU
} %HG+|)b
7He"IJ
,"`20.Lv
//保存下载信息（文件指针位置） ED>7
private void write_nPos() 5<(* +mP`
{ o!BCR:
try{ &s`)_P[
output = new DataOutputStream(new FileOutputStream(tmpFile)); bPFGQlmIO
output.writeInt(nStartPos.length); R@3HlGuRKw
for(int i=0;i<nStartPos.length;i++) Y5GN7.
{ @o0HDS
// output.writeLong(nPos); ejV`W7U
output.writeLong(fileSplitterFetch.nStartPos); YdCl
output.writeLong(fileSplitterFetch.nEndPos); (sKg*G2
} j-1V,V=
output.close(); ~%*l>GkP*
} R1LirZlzJ
catch(IOException e){e.printStackTrace ();} y ~ K8
catch(Exception e){e.printStackTrace ();} `C>h]H(
} #!Cg$6%x9
3~P$p<
g&g:HH:
//读取保存的下载信息（文件指针位置） RDbNC v#
private void read_nPos() Wmd@%K
{ nr]=O`Mvh
try{ h/\v+xiF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y05!-G:Y\
int nCount = input.readInt(); %_Vz0 D!7
nStartPos = new long[nCount]; HAO-|=c4
nEndPos = new long[nCount]; [s^pP2
for(int i=0;i<nStartPos.length;i++) /1LN\Eu
{ ]&]G
nStartPos = input.readLong(); 961&rR}d
nEndPos = input.readLong(); zRjbEL
} {1)bLG|$
input.close(); VDnrm*
} ,.P]5 lE
catch(IOException e){e.printStackTrace ();} ?/&X_O
catch(Exception e){e.printStackTrace ();} 8 siP
} 1^$hbRq
LE}`rW3
N#M>2b<A/T
private void processErrorCode(int nErrorCode) EN`JzLjP
{ 28^/By:J
System.err.println("Error Code : " + nErrorCode); G%~Vb
} |gA@$1+}
9q?knMt
5]*lH t
//停止文件下载 esSj 3E
public void siteStop() mfZbo#KS#v
{ |iJz[%
bStop = true; (Yj6|`
for(int i=0;i<nStartPos.length;i++) Q)aoc.f!v
fileSplitterFetch.splitterStop(); ;0WAfu}#H
<T7@,_T
S<]k0bC
} ^r}Uu~A>
} ek)rsxf1A
//负责部分文件的抓取 TSFrv8L
**FileSplitterFetch.java Z|@-=S(.
*/ lJAzG,f
package NetFox; kVtP~
*P *.'XM
:c]y/lQmV
import java.io.*; ~*EipxhstJ
import java.net.*; a)2l9
D7pQWlN\
ypM,i
public class FileSplitterFetch extends Thread { 6T4"m
'dwsm7Xd
; ]%fFcy
String sURL; //File URL 9*iVv)jd
long nStartPos; //File Snippet Start Position K_U`T;Z\
long nEndPos; //File Snippet End Position .nIGs'P
int nThreadID; //Thread's ID Q']'KU.
boolean bDownOver = false; //Downing is over 27gHgz}}
boolean bStop = false; //Stop identical 0*:n<T9
FileAccessI fileAccessI = null; //File Access interface h(q4 B~
BpA7 z/
KD#zsL)3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D`n<!"xg@$
{ d3EN0e+^
this.sURL = sURL; oa+'.b~
this.nStartPos = nStart; dh]Hf,OLF
this.nEndPos = nEnd; KUX6n(u
nThreadID = id; L~+aD2E {
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %zc.b
} G{.=27
XKp(31])
2 br>{^T
public void run() r8R7@S2V'
{ n)cc\JPQ
while(nStartPos < nEndPos && !bStop) 71Q`B#t0'Z
{ b^[>\s'
:F5(]g 7
~xam ;]2
try{ )`k+Oyvi<
URL url = new URL(sURL); >.39OQ#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e{2Za
httpConnection.setRequestProperty("User-Agent","NetFox"); 0F!Uai1
String sProperty = "bytes="+nStartPos+"-"; or ~@!
httpConnection.setRequestProperty("RANGE",sProperty); 7g8\q@',
Utility.log(sProperty); im>/$!&OyI
$hJ 4=F
.nr%c*JUp
InputStream input = httpConnection.getInputStream(); x?6^EB|@
//logResponseHead(httpConnection); !K_<7iExI\
\Q`#E'?
LCRWC`%&
byte[] b = new byte[1024]; ]mJ9CP8P1c
int nRead; 5-a^Frmg#"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mMZ=9 ?m
{ f3,Xb ]h
nStartPos += fileAccessI.write(b,0,nRead); k"dE?v\cG
//if(nThreadID == 1) iw(`7(*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4u p7:?
} V'.gE6we
HU +271A8
`h'Ab63
Utility.log("Thread " + nThreadID + " is over!"); %,N-M]Jf
bDownOver = true; 9[E/^
//nPos = fileAccessI.write (b,0,nRead); WFug-#;e
} <6N3()A)%1
catch(Exception e){e.printStackTrace ();} Q\~#cLJ/
} ieEtC,U
} ENYc.$r
>SZuN"r8`
AnsJ3C
//打印回应的头信息 6(Cjak+~!
public void logResponseHead(HttpURLConnection con) fb8xs<
{ kyB>]2
for(int i=1;;i++) T/L\|_:'
{ ^y&2N
String header=con.getHeaderFieldKey(i); kYS\TMt,C
if(header!=null) m&*0<N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UBwYwm0
Utility.log(header+" : "+con.getHeaderField(header)); BhyLcUBuB
else PwAmnk !
break; a<pEVV\NB~
} A[88IMZs
} GO#eI]>/r
g[{rX4~|
,;= S\
public void splitterStop() iQh:y:Jo1&
{ p{V(! v|
bStop = true; sYTToanA$?
} 78mJ3/?rC
FP6JfI8
fb]=MoiJ
} 3v~}hV/RUy
)6he;+
G~lnX^46"
/* Fw#wVs)@:
**FileAccess.java xNVSWi,
*//文件访问(定位，写) ]%5gPfv[T
package NetFox; 2Q/V D,yU
import java.io.*; ciPaCrV
KC\W6|NtGj
~r]$(V n
public class FileAccessI implements Serializable{ >&qaT*_g
3A b_Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :rmi8!o
RandomAccessFile oSavedFile; _ZuI x=!
long nPos; zy9W{{:P(1
GsWf$/iC:
oW/H8q<wY
public FileAccessI() throws IOException na/,1iI<
{ 7 (i\?
this("",0); n22OPvp
} jAFJ?L(
7mS_Cz+cB
0vz!)
public FileAccessI(String sName,long nPos) throws IOException H%Sx*|
{ Gc!&I+kd
oSavedFile = new RandomAccessFile(sName,"rw"); '^t(=02J
this.nPos = nPos; 2f0_Xw_V_
oSavedFile.seek(nPos); |i'w"Tz4
} Ef6LBNWY.
hniTMO
(7PVfS>;
public synchronized int write(byte[] b,int nStart,int nLen) %aJ8wYj*
{ LTio^uH
int n = -1; y=WCR*N
try{ p["20?^
oSavedFile.write(b,nStart,nLen); 7!, p,|K
n = nLen; $5yH8JU
} D|5Fo'O^AV
catch(IOException e) O$&4{h`
{ k{C|{m
e.printStackTrace (); v/C*?/ ~
} ^$\#aTyFK
-+.-Ab7
Hh;o<N>U
return n; R 9Yk9v
} q/\Hh9`
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'#Y[(5
} 6?jSe<4x
LfS]m>>e
/SYzo4(
/* T_?,?
**SiteInfoBean.java ;!N_8{ 7r
*/ q"^T}d d,
package NetFox; V}"w8i+D?
*}`D2_uP
TYr"yZ([
public class SiteInfoBean { *Ry "`"
5},kXXN{+
$P~Tt4068
private String sSiteURL; //Site's URL 3MFb\s&Fq
private String sFilePath; //Saved File's Path SQVyCxcX_
private String sFileName; //Saved File's Name r*s)T`T}}
private int nSplitter; //Count of Splited Downloading File |h1Y3
lw 9rf4RF
cY\"{o"C
public SiteInfoBean() i/WiSwh:
{//nSplitter的缺省值为5 8Ow0A
//default value of nSplitter is 5 GGwHz]1L
this("","","",5); be{tyV
} < {dV=
.1& F p
0(dXU\Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ns1@=f cO
{ n*fsdo~
sSiteURL= sURL; ,;wc$-Z!8
sFilePath = sPath; f)K1j{TZ
sFileName = sName; 8a4&}^|
this.nSplitter = nSpiltter; E#cZM>
.9;wJ9Bw[
.EQ1r7 9,
} B&)o:P7h
!;^TW$ G
a7Rg!%r
public String getSSiteURL() UKxeN[fv
{ cH%#qE3
return sSiteURL; b:}+l;e52
} \a\ApD
c 7uryL
/_*L8b
public void setSSiteURL(String value) kUG3_ *1 .
{ .!hB tR
sSiteURL = value; K2R[u#Q
} {n>W8sN<
j8Csnm0
#/Qe7:l
public String getSFilePath() ~'l.g^p bv
{ *b0f)y3RV
return sFilePath; }PDNW
} 0if~qGm=!
C|A:^6d3=
_~E&?zR2>"
public void setSFilePath(String value) p#95Q
{ PH}^RR{H[
sFilePath = value; f}>S"fFI
} hd}"%9p
~?)ST?&
mT2Fn8yC1
public String getSFileName() jFBnP,WQ
{ %A<|@OSdOa
return sFileName; R\wG3Oxol
} lx&ME#~
&N!;d E
[!E8C9Q#!
public void setSFileName(String value) |F 18j9
{ +wwK#ocw
sFileName = value; -]h3s >t
} ;tF7GjEp
)0:@T)G
T;%ceLD
public int getNSplitter() to
{ c|'hs
return nSplitter; }~RH!Q1
} !Z6GID})p
:!f1|h
$fE$j {
public void setNSplitter(int nCount) A,T3%TE
{ M/,jHG8v
nSplitter = nCount; &<P!o_+eb
} z;_d?S<*m
} kOGpe'bV
i+V4_`
3wBc`vJ!
/* sc! e$@U
**Utility.java v*nX
*/ E30VKh |
package NetFox; J8"Cw<=O
g[P8
J8x>vC
public class Utility { r$*p
VlVd"jW
;Vad| -
public Utility() j/R
{ .TURS
;TK:D=p4
av1*i3
} /EOtK|E
{qm(Z+wcmb
//线程睡眠 Cp_YIcnEJ
public static void sleep(int nSecond) @GYM4T
{ bqMoO7&c
try{ TWC^M{e
Thread.sleep(nSecond); 7ST[XLwt%}
} TCSm#?[B
catch(Exception e) m(Cn'@i`"0
{ ]~z2s;J{/
e.printStackTrace (); ESZ6<!S
} b "4W` A
} SLc6]?
I hvL2zB
//日志 =^P<D&%q
public static void log(String sMsg) RkN a;j)t
{ R0M(e@H~
System.err.println(sMsg); mB$r>G/'
} eD*"#O)W
".qh]RVjV
+[JGi"ca
public static void log(int sMsg) 6M"]p
{ 6|05-x|
System.err.println(sMsg); i%M2(8&^Q
} ~PUz/^^ s
} %/H
@fp(uu
aT#R#7<Eg
/* 5w`v 3o
**TestMethod.java !V.'~xj
*/ <BQ4x.[
package NetFox; 6ZVJ2xs[%
.3,s4\.kT
JQ%`]=n(/
public class TestMethod { J%3%l5/
Z^AACKME
">kfX1LT
public TestMethod() X;T(?,,
{ ///xx/weblogic60b2_win.exe W:P4XwR{
try{ Cl]E rg
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~?dPF;.6_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aU2O5z&
SiteFileFetch fileFetch = new SiteFileFetch(bean); {vAq08
fileFetch.start(); EpeTfD
} "j9,3yJT
catch(Exception e){e.printStackTrace ();} 38%]GQ
s} ,p>8
:?{ **&=
} Nl7"|()e
Fk>/
b:>(U.
public static void main(String[] args) z@$7T:H>
{ O'" &9
new TestMethod(); |-I[{"6q$@
} Xi5ZQo!t
} Tc@r#!.m
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