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)); wJMk%N~R:
} .mwB'Ll
for(int i=0;i<nEndPos.length-1;i++) &$L6*+`h#
{ yhG%@vSq
nEndPos = nStartPos[i+1]; 1];OGJuJ2
} "HwSW4a]
nEndPos[nEndPos.length-1] = nFileLength; U6x$R O!
} tQ7:4._
} Y6:b
67D{^K"KT
d$qi.%<kh
//启动子线程 e~P4>3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?(R!BB
for(int i=0;i<nStartPos.length;i++) oo-O>M#5
{ wT>~7$=L{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1<;RI?R[9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,`,1s9\&t
nStartPos,nEndPos,i); 57(5+Zme
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,Z$!:U
fileSplitterFetch.start(); o*sss
} &qyXi[vw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VKMgcfbHr/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E]dc4US
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", twP%+/g]<
nEndPos = " + nFileLength); AkAQ%)6qV
// fileSplitterFetch[nPos.length-1].start(); Z_Y' 3'^Tw
7Q0vwKC8>
w\lc;4U
//等待子线程结束 zGaqYbQD
//int count = 0; >qS2ha
//是否结束while循环 4QBPN@~t
boolean breakWhile = false; 'y&DOy/|
YkF52_^_
J b?x-%Za
while(!bStop) ~?zu5,vb
{ YVLK X}$)(
write_nPos(); %:N;+1
Utility.sleep(500); uNf97*~_
breakWhile = true; Vy7 )_D
}6"l`$=Ev
te;VGpv.
for(int i=0;i<nStartPos.length;i++) e/b | sl
{ y<kg;-& 8
if(!fileSplitterFetch.bDownOver) -,q qQf
{ $6]1T>
breakWhile = false; %$'Z"njO&
break; I#/"6%e
} 8Om4G]*|,
} sspGB>h8l
if(breakWhile) 2"EaF^?\
break; -_BX\iP{
+zf`_1+)U
V3<#_:;
//count++; |]eWO#vs
//if(count>4) y*!8[wASHq
// siteStop(); {hoe^07XK
} VV"w{#XKw
V;"Rp-`^
7LsVlT[
System.err.println("文件下载结束！"); nd"$gi
} ]fSpG\yU
catch(Exception e){e.printStackTrace ();} vr4{|5M
} q<[o 4qY
aH\A
UAGh2?q2
//获得文件长度 @w(X}q1
public long getFileSize() Y+eDE:4
{ 0xH&^Ia1B
int nFileLength = -1; 5p ,HkV
try{ ul]hvK{2
URL url = new URL(siteInfoBean.getSSiteURL()); EFv^uve
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wQ8<%qi"L
httpConnection.setRequestProperty("User-Agent","NetFox"); e?pQuF~
P1R[M|Fx
^ywDa^;-
int responseCode=httpConnection.getResponseCode(); 6?a z
if(responseCode>=400) eQ*zi9na
{ rdsZ[ii
processErrorCode(responseCode); UG3}|\.u
return -2; //-2 represent access is error ^%0^DN
} ^fE8|/]nG9
@|{8/sOq
_jH./ @G
String sHeader; )4N1EuD6
-@@ O<M^
#Z,@yJ2wl
for(int i=1;;i++) Eqi;m,)
{ H;0K4|I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5n1`$T.WG
//Utility.log(in.readLine()); p_vldTIW
sHeader=httpConnection.getHeaderFieldKey(i); O$N;a9g
if(sHeader!=null) DXQ]b)y+N
{ Dl,sl>{
if(sHeader.equals("Content-Length")) MI-S}Qoe
{ Q(O0z3b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )l.AsfW%
break; wc-v]$DW
} Hp5.F>-
} Jp|eKZ
else E)wf'x
break; JeF$ W!!{
} ]Inu'p\
} ;j qF:Wl@
catch(IOException e){e.printStackTrace ();} ~NLthZ(O
catch(Exception e){e.printStackTrace ();} KT+{-"4-
)2#qi/
YT,yRV9#
Utility.log(nFileLength); p'6XF{
C6Cr+TScH
F_I!qcEQ
return nFileLength; k~I]Y,
} f=.!/e70
;-BN~1Jg
:X:s'I4J D
//保存下载信息（文件指针位置） j\zlp
private void write_nPos() Vbe@S?u-
{ k~3\0man
try{ %yd(=%)fMB
output = new DataOutputStream(new FileOutputStream(tmpFile)); 78 ]Kv^l^_
output.writeInt(nStartPos.length); _1mpsY<k
for(int i=0;i<nStartPos.length;i++) )y i~p
{ G!wb|-4<$
// output.writeLong(nPos); 8nL9#b
output.writeLong(fileSplitterFetch.nStartPos); t0r0{:
output.writeLong(fileSplitterFetch.nEndPos); pzaU'y#PM
} iX<" \pV
output.close(); H=w):kL|
} q'4P/2)va
catch(IOException e){e.printStackTrace ();} @vXXf/
catch(Exception e){e.printStackTrace ();} ru6M9\h*
} VW*?(,#j{
6VuyKt
vLBuE
//读取保存的下载信息（文件指针位置） O[{/P:a
private void read_nPos() 7l[@c|e
{ $ZZ?*I
try{ H9i7y,[*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B3D}'<
int nCount = input.readInt(); MkjB4:"
nStartPos = new long[nCount]; Gqc6]{
nEndPos = new long[nCount]; GB<.kOGQ[
for(int i=0;i<nStartPos.length;i++) ?1c7wEk
{ Kf}*Ij
nStartPos = input.readLong(); @YQ*a4`
nEndPos = input.readLong(); 6xwjKh:9
} 6({)O1Z
input.close(); J/E''*
} ]z8/S!?
catch(IOException e){e.printStackTrace ();} Rm}5AJ
catch(Exception e){e.printStackTrace ();} ^Ifm1$X}
} BD;T>M
m. p'LF
B!;:,(S~
private void processErrorCode(int nErrorCode) %'_:#!9
{ 9I2&Vx=DSt
System.err.println("Error Code : " + nErrorCode); ],[<^=|
} nM:<l}~v{
lY(_e#
YVvE>1z
//停止文件下载 @mv G=:k
public void siteStop() OcPgw/ I
{ &A.0(s
bStop = true; wIR"!C>LE
for(int i=0;i<nStartPos.length;i++) ='w 2"4
fileSplitterFetch.splitterStop(); iAk.pH]a
7&wxnxSk^
d4ld-y
} OIpT9
} ,7:-V<'Yv
//负责部分文件的抓取 ef&8L
**FileSplitterFetch.java 9W]OtSG
*/ ti6X=@ P:
package NetFox; QdcuV\B}
qm_m8
WFV'^-4
import java.io.*; 6| o S 5
import java.net.*; , .~k
M|h B[
PN8#T:E
public class FileSplitterFetch extends Thread { #qF1z}L(
E@xrn+L>-
u kZK*Y9P
String sURL; //File URL u^|cG{i5"
long nStartPos; //File Snippet Start Position z_lKq}^~6
long nEndPos; //File Snippet End Position ok:L]8UN3
int nThreadID; //Thread's ID 3)#Nc|
boolean bDownOver = false; //Downing is over .zt&HI.F
boolean bStop = false; //Stop identical 7}~w9jK"F
FileAccessI fileAccessI = null; //File Access interface "M-';;
WwZ3hd
PH:5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException JrLh=0i9
{ @#N7M2/
this.sURL = sURL; ;n*|AL7(
this.nStartPos = nStart; kqj)&0|X
this.nEndPos = nEnd; XR7v\rd
nThreadID = id; z_R^C%0k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [:gg3Qzx
} j\bp#+
5VOw}{Pt
^t7u4w!
public void run() Keo<#Cc?
{ o/VT"cT
while(nStartPos < nEndPos && !bStop) g~.#.S ds
{ <&) hg:
=j- ,yxBvJ
] L#c <0
try{ WrDFbcH
URL url = new URL(sURL); f"j9C%'*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NNqvjM-
httpConnection.setRequestProperty("User-Agent","NetFox"); V?G%-+^
String sProperty = "bytes="+nStartPos+"-"; d^6-P R_
httpConnection.setRequestProperty("RANGE",sProperty); ,C><n kx
Utility.log(sProperty); jxkQ #Y
h~9P34m
K`9~#Zx$
InputStream input = httpConnection.getInputStream(); 4D<C;>*/b
//logResponseHead(httpConnection); )}N:t:rry
p2rT0gu!
?uL-qsU
byte[] b = new byte[1024]; =6:9y}~
int nRead; 579D
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @SxZ>|r-|v
{ =gJ{75tV3
nStartPos += fileAccessI.write(b,0,nRead); 80Fa i
//if(nThreadID == 1) o jxK8_kl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #\Y`?
} 5,^DT15a4P
KyVzf(^
,qp8Rg|3j
Utility.log("Thread " + nThreadID + " is over!"); yeta)@nH
bDownOver = true; 2%R.~9HtA
//nPos = fileAccessI.write (b,0,nRead); )6p6<y
} Pi?G:IF
catch(Exception e){e.printStackTrace ();} svEe@Kt`
} E+XS7':I
} @#W4?L*D
:^{KY(3
U&R)a| 7R
//打印回应的头信息 OZf@cOTWK
public void logResponseHead(HttpURLConnection con) 2Ul8<${c{
{ `G:1
for(int i=1;;i++) C|Gk}
{ =e#h;x2
String header=con.getHeaderFieldKey(i); /P9fcNP{y
if(header!=null) QbHX.:C
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P~!,"rY
Utility.log(header+" : "+con.getHeaderField(header)); p>?(uGV
else ~PyS;L}
break; .kuNn-$
} k.54lNl
} ?nL,Otz
"pK<d~Wu
%?+Lkj&
public void splitterStop() A*+gWn,4Y_
{ 4Lk<5Ho
bStop = true; N\tFK*U^I
} j]%XY+e
1I'Q{X&B
V73/q
} *mj=kJ7(
^b5+A6?
o58c!44
/* \5<Z[#{
**FileAccess.java d#d&CJAfr
*//文件访问(定位，写) Z6Mjc/
package NetFox; ( 6zu*H)
import java.io.*; 38X{>*
_(:$ :*@
fH9"sBiO
public class FileAccessI implements Serializable{ :'q$emtY
0'A"]6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OUwnVAZZ6
RandomAccessFile oSavedFile; WB'1_a
long nPos; x.pg3mVd>
nLk`W"irM
Q;q{1M>
public FileAccessI() throws IOException \C>vj+!cJ
{ b-@9Xjv
this("",0); 8sI$
} N|"kuRN#
Xj30bt
-jrAk
public FileAccessI(String sName,long nPos) throws IOException HFyQ$pbBU
{ %yfl-c(u
oSavedFile = new RandomAccessFile(sName,"rw"); #v~dhx=R
this.nPos = nPos; q;sZwp<
oSavedFile.seek(nPos); cZoj|=3a
} EX, {1^h
ve.P{;;Ky
7\nXJ381
public synchronized int write(byte[] b,int nStart,int nLen) '?_~{\9<
{ 4eSFpy1
int n = -1; *6=9 8C4I
try{ NZ!I >
oSavedFile.write(b,nStart,nLen); ./'d^9{
n = nLen; @y * TVy
} i<tJG{A=
catch(IOException e) H*f2fyC1\
{ (64es)B}"
e.printStackTrace (); a{JO8<dlm
} <A\g*ld
\ sz](X
kY4h-oZ
return n; DEfhR?v
} R iLqMSq
x<d ew
:}SR{}]yXs
} %hBw)3;l
.'-t>(}v
[a^<2V!vMn
/* 1&=2"
**SiteInfoBean.java rX`fjS*C
*/ ZiH4s|
package NetFox; bhZ5-wo4%
|NjyO>@Pa
wlP% U
public class SiteInfoBean { e6T?2`5P
lL'K1%{+ \
^ilgd
private String sSiteURL; //Site's URL 2v*X^2+
private String sFilePath; //Saved File's Path n2F*a
private String sFileName; //Saved File's Name &(x>J:b
private int nSplitter; //Count of Splited Downloading File sJg3WN
TQ {8 ee{
f,@~@f X
public SiteInfoBean() 4 T/ ~erc
{//nSplitter的缺省值为5 Jx4~o{Z}c
//default value of nSplitter is 5 7:.!R^5H
this("","","",5); ;:)u rI?
} 6H|T )
WCI'Kh
PCKxo;bD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fjQIuM
{ kY~yA2*G
sSiteURL= sURL; L{c\7
sFilePath = sPath; ~;wR}s<}(
sFileName = sName; <&t[E0mU
this.nSplitter = nSpiltter; SQw"mO
K~8!Gh{h]
.d4&s7n0
} ]b^bc2:
%NL7XU[~
P\ 2Bx *e
public String getSSiteURL() VF"c}
{ #Pq6q.UB
return sSiteURL; t 9.iWIr
} I]d?F:cdX
&#]||T-
34vH+,!u
public void setSSiteURL(String value) -r{]9v2j
{ yv5c0G.D
sSiteURL = value; {JcMJZ3
} 2|+4xqNJm
kr]_?B(r
YdAC<,e&A
public String getSFilePath() ".fnx8v,
{ 00A2[gO9
return sFilePath; vmtmiN8;d
} bgmOX&`G
|Gb~[6u
w:9n/[
public void setSFilePath(String value) ^`(3X
{ As#/ln$nE
sFilePath = value; )|S!k\^A
} ~eGtoEY
Jz_`dLL^w
qI\B;&hr(
public String getSFileName() LoS%FI
{ b=Q%Jxz?
return sFileName; YccD^w[`B
} T:udw
N8]d0
SjU0Xb)[
public void setSFileName(String value) u O~MT7~[X
{ Uw>g^[V;
sFileName = value; oVnHbvP1X
} d[KG0E5`
[i N}W5 m
_5768G`P
public int getNSplitter() `"E<%$|ZQy
{ xTdh/}
return nSplitter; ZCkwK
} !iGZo2LV
|Iq\ZX%q
.n| M5X
public void setNSplitter(int nCount) =)XC"kUp
{ Hh<}~s
nSplitter = nCount; G]fx3=
} e%&/K7I"?
} qznd'^[
?$X1X`@
6imQjtI
/* e_CgZ
**Utility.java y+a]?`2
*/ ;jpsH?3g
package NetFox; .AHww7
SNf*2~uq)
lA7\c#
public class Utility { \RyW#[(
QW}N,j$
'd=B{7k@
public Utility() &r!*Y&
{ .^* .-8q
OLxiY r
Z&0*\.6S~
} I)X33X,
1C\[n(9
//线程睡眠 <al/>7z' O
public static void sleep(int nSecond) o8ADAU"
{ c27A)`
try{ @,v.Y6Ge
Thread.sleep(nSecond); *H%Jgz,
} C)`y<O
catch(Exception e) elm]e2)F
{ *H,vqs\}y
e.printStackTrace (); veh?oJi@
} *4F6U
} ;3WVrYe
6N'v`p8
//日志 N!:&Xz
public static void log(String sMsg) 3)+}2
{ (y!<^Q
System.err.println(sMsg); F2RU7o'f.
} :Sd iG=t
?Dk&5d^d
re\&'%~K
public static void log(int sMsg) Vi1= E])
{ x*uQBNf=
System.err.println(sMsg); oefhJM!y
} jO#5ZhG
} 8yV?l7
ohe0}~)V
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/* juQQ
**TestMethod.java }_L,Xg:I
*/ Fm3B8Int
package NetFox; Ks@
8n^v,s>
9My |G)M6
public class TestMethod { nv^nq]4'Dq
h"{Z%XPX#
\vvV=iw
public TestMethod() L<**J\=7M
{ ///xx/weblogic60b2_win.exe PYp<eo\
try{ TS{ycGY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8Yq_6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o3~ecJ?k
SiteFileFetch fileFetch = new SiteFileFetch(bean); \-B8`ah
fileFetch.start(); J2W:Q
} R4Vi*H
catch(Exception e){e.printStackTrace ();} {m/h3hjFa
]N+(SU
9,`eYAu
} 'X$2gD3c9
g~JN"ap
%4~2
public static void main(String[] args) ],HF)21
{ q'%-8t
new TestMethod(); <k0$3&D
} 2#bpWk9
} gE>_:s
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