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)); vh|m[p
} ^-Ks_4
for(int i=0;i<nEndPos.length-1;i++) ]=3hH+1 a
{ 1C=42ZZ&2
nEndPos = nStartPos[i+1]; LvGo$f/9
} +pUYFDwFx
nEndPos[nEndPos.length-1] = nFileLength; M~X~2`fFH
} dXWG`G_
} 7lOAu]Zx
D41.$t[
M"-53|#:w\
//启动子线程 .K_50%s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0m4#{^Y
for(int i=0;i<nStartPos.length;i++) 1JS5 LS
{ 7wrRIeES
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %h_N%B$7c1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .F/l$4CQ
nStartPos,nEndPos,i); fX LsLh+~D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uYE"OUNWL
fileSplitterFetch.start(); M6[O>z
} 2_6@&2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _Fkb$NJ"]Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gxDyCL$h3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3!KyO)8
nEndPos = " + nFileLength); (^ J2(
// fileSplitterFetch[nPos.length-1].start(); nS!m1&DeD
| m#"
pfMmDl5|
//等待子线程结束 gE23C*!'&:
//int count = 0; EBmkKiI;
//是否结束while循环 sEa|2$
boolean breakWhile = false; w\JTMS$
ypvz&SzIh
On;7
while(!bStop) _k)EqPYu@
{ o^d
write_nPos(); |kHzp^S
Utility.sleep(500); $3Sm?
breakWhile = true; :Q;mgHTNz
6(B[(Af
ad<ZdO*h
for(int i=0;i<nStartPos.length;i++) x,<|<W5<%
{ YB9)v5Nz(
if(!fileSplitterFetch.bDownOver) q$B|a5a?
{ _dVA^m
breakWhile = false; %G,d&%f
break; *)T7DN8
} Zu ![v0
} ?[8s`caK.
if(breakWhile) /6'5uP
break; xQs._YY
qD(dAU
h(FFG%H(
//count++; %hA0
//if(count>4) E>1%7" i<
// siteStop(); E(an5x/r
} BKfoeN)%
(+9^)No
Uclta
System.err.println("文件下载结束！"); NvJ}|w,Z
} 'Fa~l'G7X
catch(Exception e){e.printStackTrace ();} bx3kd+J7
} kXZG<?
M~*o =t
a_Z[@W
//获得文件长度 ;TCT%j`^o
public long getFileSize() >^adxXw.o
{ y.WEO>
int nFileLength = -1; Y'x+!&H
try{ $&FeR*$|g
URL url = new URL(siteInfoBean.getSSiteURL()); 71k>_'fl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f5vsxP)Y[
httpConnection.setRequestProperty("User-Agent","NetFox"); hR~~k~84
L[}Ak1 A
0`kaT ?>
int responseCode=httpConnection.getResponseCode(); ;c0z6E /
if(responseCode>=400) -<@QR8:
{ j%Z%_{6Ds*
processErrorCode(responseCode); m 3"|$0C~
return -2; //-2 represent access is error K`twbTU
} 52z{
q,2 +\i
kTS#>uS
String sHeader; 69EdMuf
{Nny.@P)H
{*t0WE&1t
for(int i=1;;i++) yq\p%z$:
{ 9\a;75a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t(5PKD#~Dc
//Utility.log(in.readLine()); T8-,t];i
sHeader=httpConnection.getHeaderFieldKey(i); U|)CZcM
if(sHeader!=null) Ggp.%kS6F
{ J(=io_\bO
if(sHeader.equals("Content-Length")) q#t&\M.U
{ I?Ct@yxhF'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y-^m
break; o@A|Lm.
} @_C?M5v
} ctu`FQ
else >}6V=r3[+
break; &u~#bDh
} h!q_''*;
} db5@+_
catch(IOException e){e.printStackTrace ();} <5:`tC2
catch(Exception e){e.printStackTrace ();} eeu;A,@U
!OL[1_-4|K
< r7s,][&
Utility.log(nFileLength); 6z ,nt
CH+mzy
&(i_s
return nFileLength; QeNN*@ ='i
} ^QTtCt^:
#jd&f,Tt
L@>$ Aw
//保存下载信息（文件指针位置） #f-pkeaeq
private void write_nPos() vG'I|OWg
{ :DoE_
try{ 1?,1EYT"
output = new DataOutputStream(new FileOutputStream(tmpFile)); a5nA'=|}i
output.writeInt(nStartPos.length); kYnp$8
for(int i=0;i<nStartPos.length;i++) u;3wg`e
{ LMTz/M
// output.writeLong(nPos); o GN*p_g
output.writeLong(fileSplitterFetch.nStartPos); l7vxTj@(-
output.writeLong(fileSplitterFetch.nEndPos); ?3Y~q;I]O
} O#72h]
output.close(); -0f,qNF
} \^]*T'>b
catch(IOException e){e.printStackTrace ();} crl"Ec
catch(Exception e){e.printStackTrace ();} \k>1q/T0V
} gUHx(Fi[4
fF]w[lLDv
3:"w"0[K3
//读取保存的下载信息（文件指针位置） :jr`}Z%;y
private void read_nPos() U\GuCw
{ 0I['UL^!F
try{ ^\C Fke=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HvLx
int nCount = input.readInt(); %_%BbQf
nStartPos = new long[nCount]; ae0t*;~
nEndPos = new long[nCount]; P^[y~I#{
for(int i=0;i<nStartPos.length;i++) J^y?nE(j
{ /X;/}fk
nStartPos = input.readLong(); hI 1or4V
nEndPos = input.readLong(); za!8:(
} C2C1 @=w
input.close(); `lA_knS
} ,)M/mG?,
catch(IOException e){e.printStackTrace ();} SW)jDy
catch(Exception e){e.printStackTrace ();} wDDNB1_E
} 3@42uG>
" 6ScVa5)
&a.A8v)
private void processErrorCode(int nErrorCode) l1vI
{ qPBOt;N
System.err.println("Error Code : " + nErrorCode); <b:xyHS
} j]C}S*`"
K5!OvqzG
A DVUx}
//停止文件下载 a:Nf+t
public void siteStop() <$??Z;6
{ Xo$SQ0K
bStop = true; gI!d*]{BP
for(int i=0;i<nStartPos.length;i++) CaC \\5wl
fileSplitterFetch.splitterStop(); {2k]$|
^.9DfA0
%{-r'Yi%
} Qk >9o
} :b] \*
//负责部分文件的抓取 \q\"=
**FileSplitterFetch.java nyetK
*/ mLx=Zes:.
package NetFox; Q5lt[2Zyzd
4n"6<cO5q
!yd]~t 5Q
import java.io.*; 0SQrz$y
import java.net.*; 1'N<ITb
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{Fqwr>e
public class FileSplitterFetch extends Thread { K|Eelhm
3"juj'
4/%Y@Z5
String sURL; //File URL n =WH=:&
long nStartPos; //File Snippet Start Position 3b|=V
long nEndPos; //File Snippet End Position C`R<55x6
int nThreadID; //Thread's ID icb*L~qm
boolean bDownOver = false; //Downing is over pKno~jja
boolean bStop = false; //Stop identical % m"Qg<
FileAccessI fileAccessI = null; //File Access interface 3-&~jm~"
w51l;2$des
@v#,SF{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *AP"[W
{ 8t. QFze?
this.sURL = sURL; lXZ*Pb<j
this.nStartPos = nStart; c&I
this.nEndPos = nEnd; ^/6P~iK'
nThreadID = id; ;rF[y7\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hNhEA $X5
} KyyVO"
T9XUNR{&
H\qZu%F'
public void run() !^ad{#|X
{ ];lZ:gT
while(nStartPos < nEndPos && !bStop) d^J)Mhju
{ g8l6bh$}
xQ7U$QF|]
d#]hqy
try{ 1]eRragm"
URL url = new URL(sURL); s5rD+g]E`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \PUJD,9H
httpConnection.setRequestProperty("User-Agent","NetFox"); tv.<pP9-C
String sProperty = "bytes="+nStartPos+"-"; f*B-aj#
httpConnection.setRequestProperty("RANGE",sProperty); fBctG~CJH
Utility.log(sProperty); ~bCA8
M;,$ )>P
Z.u1Dz
InputStream input = httpConnection.getInputStream(); pA8As
//logResponseHead(httpConnection); p7@R+F\.};
]/H6%"CTa
g27'il
byte[] b = new byte[1024]; KMz!4N
int nRead; aY#?QjL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8\!E )M|4
{ 9i}$245lB
nStartPos += fileAccessI.write(b,0,nRead); 4&;iORw&E4
//if(nThreadID == 1) xsn=Ji2 F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GPK\nz}
} O"+0 b|
No} U[u.O
_OTVQo Ap
Utility.log("Thread " + nThreadID + " is over!"); D,ZLo~
bDownOver = true; %&yPl{
//nPos = fileAccessI.write (b,0,nRead); 1QG q;6\
} +q'1P}e
catch(Exception e){e.printStackTrace ();} ;6Yg}L
} fDf[:A,8
} .Mb[j1L^
uW(-?
o#e8 Piw
//打印回应的头信息 X!ruQem /
public void logResponseHead(HttpURLConnection con) [jzsB:;XB&
{ TXmS$q
for(int i=1;;i++) hOUH1m.
{ 'R79,)|;[
String header=con.getHeaderFieldKey(i); B5;%R01A
if(header!=null) () _RLA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7;fC%Fq
Utility.log(header+" : "+con.getHeaderField(header)); ^w\22 Q
else q2vD)r
break; )N&SrzqTK
} N3|:MMl
} 0%rDDB
fd&Fn=!
\Y)HSJR;e
public void splitterStop() FBNLszT{L
{ {fR\yWkt?
bStop = true; 5-|!mSd
} My8d%GfM
8(%F{&<;
Xfq`k/ W
} G&g;ROgY
E(r_mF7:
@.eN+o9|
/* 73cb1kfPd
**FileAccess.java 4^L;]v,|7
*//文件访问(定位，写) ^Spu/55_
package NetFox; |IcW7(
import java.io.*; ,<rC,4-F<
JY,$B-l
xaMDec V
public class FileAccessI implements Serializable{ Te+(7 Z
!<p,G`r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6nW)2LV
RandomAccessFile oSavedFile; 4E^ ?}_$
long nPos; M}\h?s
,eyh%k*hz
7S a9
public FileAccessI() throws IOException duY?LJ@g
{ [I *_0
this("",0); y8k8Hd1<f
} G"<#tif9K
!?P8[K
/+Z*)q+SbT
public FileAccessI(String sName,long nPos) throws IOException HOP*QX8C%
{ :V'99Esv`
oSavedFile = new RandomAccessFile(sName,"rw"); fqgp{(`@>
this.nPos = nPos; DSU8jnrL
oSavedFile.seek(nPos); PK[mf\G\
} -5<[oBL;
B6 0
W+ S~__K
public synchronized int write(byte[] b,int nStart,int nLen) o$No@~%v
{ 8o~ NJ 6
int n = -1; ukiWNF/
try{ /hl'T'RG
oSavedFile.write(b,nStart,nLen); 6'#5Dqw"r
n = nLen; pa>C}jk}6
} 5CY%h
catch(IOException e) m+(Cl#+
{ 9;@p2t*v
e.printStackTrace (); E 2nz
} W"NI^OX
981-[ga`Y
T9nb ~P[
return n; [}L~zn6>?a
} &QHJ%c
(/]'e}
0kE[=#'.'
} pfN(Ae Pt
W==~9
e*:K79y
/* 1VJ${\H]
**SiteInfoBean.java *vb"mB
*/ Z [!"x&H]h
package NetFox; }3#\vn0gT
RjWwsC~B
_Y; TS1u
public class SiteInfoBean { f[o~d`z
-UhpPw6
9j2t|D4uT
private String sSiteURL; //Site's URL N5?bflY
private String sFilePath; //Saved File's Path :v^/k]S
private String sFileName; //Saved File's Name !5ps,+o
private int nSplitter; //Count of Splited Downloading File Qq,2V
h^3gYL7O6
zdYH9d>D
public SiteInfoBean() 7]VR)VAM
{//nSplitter的缺省值为5 uxfh?gsL
//default value of nSplitter is 5 f}-'67*Y
this("","","",5); 9X*Nk~}Y
} k|;a"56F
e9LX0=
-@>{q/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "Z@P&jl
{ ^'X I%fEf
sSiteURL= sURL; @O#!W]6NT6
sFilePath = sPath; VX)8pV$
sFileName = sName; /v!yI$xc
this.nSplitter = nSpiltter; p(F@lL-
]Uv,}W
f{9+,z
} 0z=KnQx"4
+<bj}"
I5"wa:Z
public String getSSiteURL() 7@c!4hmrU
{ P+CV4;Xz
return sSiteURL; i%i~qTN
} tD8fSV
zhJeTctRz
!9d7wPUFr
public void setSSiteURL(String value) Ct=bZW"j/
{ Z`-$b~0
sSiteURL = value; !U`4
} >2#<gp3
v47' dC
A'EI1_3{
public String getSFilePath() Iy)1(upM
{ x1:mT[[$
return sFilePath; {6u)EJ
} }IygU 6{G
@5Tl84@Q
dDS{XR
public void setSFilePath(String value) ^wy
{ S?v/diK ]J
sFilePath = value; "leSQ
} ;lmg0dtJ
Tg)F.):
[Qs`@u<%
public String getSFileName() "ku[b\W
{ $:s@nKgnD~
return sFileName; uzp\V 39
} )WvKRp r
I[E 6N2
JpXv+V
public void setSFileName(String value) c|<F8n
{ ]t<=a6<P
sFileName = value; 0YoKSo
} _`gF%$]b
!$Uo$?gC
7nPg2K&
public int getNSplitter() 45biy(qa
{ u-~ec{oBu
return nSplitter; 1XiA
} YI0l&'7
C2<TR PT
"e-z2G@z
public void setNSplitter(int nCount) ~2*LWH*@
{ bB4FjC':
nSplitter = nCount; >|S@twy
} ^S|qGu,G
} EI=~*&t
}/J"/ T
-+F,L8
/* k*_Gg
**Utility.java 6EC',=)6R
*/ Zwq\m.h
package NetFox; v RD/67
KS#A*BRQ
5_yw
public class Utility { L%H\|>k`
Wm1dFf.>
]$#bNt/p
public Utility() ;):;H?WS|A
{ ~AWn 1vFc
0;x&\x7K
wMkHx3XD
} nHF66,7t
{_tq6ja-<
//线程睡眠 TgJ+:^+0
public static void sleep(int nSecond) N?c~AEk9U
{ st??CX2
try{ 8nZ_.
Thread.sleep(nSecond); 3` IR ^
} e 6wevK\
catch(Exception e) ,fiV xnQ
{ .0,G4k/yv
e.printStackTrace (); N5W!(h)
} kJ%a;p`O
} 1OvoW Nx
;^JMX4[
//日志 j0"4X
public static void log(String sMsg) >'#vC]@
{ w15a~\Qu
System.err.println(sMsg); pFs/ipZX^*
} zA?AX1%Wa
l?b*T#uIk
ouyZh0G
public static void log(int sMsg) [c;0eFSi2
{ Gv]94$'J9
System.err.println(sMsg); 16N|
} djoP`r
} daCkjDGl\
'b"7Lzp2
V:t{mu5j
/* :RDk{^b)
**TestMethod.java bz 7?F!
*/ )l(DtU!E
package NetFox; zXUB6. e
#zgO_H
b%x=7SMXO
public class TestMethod { 74NL)|M
EqBTN07dZS
<3ep5`1
public TestMethod() g/FT6+&T.
{ ///xx/weblogic60b2_win.exe 7wY0JS$fz
try{ }4piZ ch
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xY.?OHgG/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J0f!+]~G3
SiteFileFetch fileFetch = new SiteFileFetch(bean); o:*$G~. k
fileFetch.start(); 3me&isKL
} fGA#0/_`
catch(Exception e){e.printStackTrace ();} OaT]2o
n``9H91
"E4CQL'U
} }Q\+w,pJgN
p Djt\R<f
vxi_Y\r=T
public static void main(String[] args) !,Cbb }
{ A42!%>PB
new TestMethod(); WuI$
} JJs*2y
} x|c_(
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