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)); =(>pv,
} ;*8,PV0b_<
for(int i=0;i<nEndPos.length-1;i++) mA']*)L1
{ I>3]VRi
nEndPos = nStartPos[i+1]; p EbyQ[
} S9S%7pE
nEndPos[nEndPos.length-1] = nFileLength; .t|B6n!
} *z\L
} HFrwf{J
YST{ h{
#R3|nL
//启动子线程 5Qgh\4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =LMM]'no,
for(int i=0;i<nStartPos.length;i++) .Zv uhOn^
{ 0:4w@"Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qEV>$>}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ju?D=n@i
nStartPos,nEndPos,i); Lkl^ `
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Mi&jl_&
fileSplitterFetch.start(); $|bdeQPr\
} &>%9JXU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xc6A&b>jI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5\eM3w'd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6'1m3<G_
nEndPos = " + nFileLength); d;O4)8>
// fileSplitterFetch[nPos.length-1].start(); O;?Nz:/q
O4fl$egQU
8P3"$2q
//等待子线程结束 5]yby"Z?}
//int count = 0; z;ko )
//是否结束while循环 a EmLf
boolean breakWhile = false; _mn2bc9M
ORP-@-dap
V`XtGTx
while(!bStop) %/Y;
{ w [7vxQ!-
write_nPos(); 3Ja1|;(2
Utility.sleep(500); rc+}KO
breakWhile = true; dw]jF=u
._IBO;*@
/32x|Ow# 1
for(int i=0;i<nStartPos.length;i++) Sn!5/9Y
{ DDwm;,eZ
if(!fileSplitterFetch.bDownOver) N.@@ebuE
{ sW]fPa(cn,
breakWhile = false; &pZncm
break; RYuR&0_{
} }MXC0Z~si
} xb~8uD5
if(breakWhile) @j|=M7B
break; j0+l-]F-
G2BB]] m3
Kk9W=vd
//count++; s'Wu \r'
//if(count>4) M"Q{lR
// siteStop(); ];8S<KiS~
} 1'"TO5
r`GA5}M
5isqBu
System.err.println("文件下载结束！"); G"|`&r@
} lLi)?
catch(Exception e){e.printStackTrace ();} K)[DA*W
} S{#L7S
K]c\3[vR
.bvEE
//获得文件长度 /Mmts=^Ja
public long getFileSize() Y~[k_!
{ {YigB
int nFileLength = -1; Usz O--.C
try{ @[. 0,
URL url = new URL(siteInfoBean.getSSiteURL()); T_/ n#e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1E]TH/JK
httpConnection.setRequestProperty("User-Agent","NetFox"); * faG0le
S5>?jn1
7/b\NLeJ'
int responseCode=httpConnection.getResponseCode(); FH7h?!|t
if(responseCode>=400) ee\QK,QV
{ zVyMmw\
processErrorCode(responseCode); Q.Xs%{B
return -2; //-2 represent access is error LZH~VkK@m}
} 'K*. ?M
m;@8z[ ^5
&-zW1wf
String sHeader; L| K8
OD;F{Hc
g`\5!R1
for(int i=1;;i++) `b?o%5V2x
{ S}/5W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^bG91"0A
//Utility.log(in.readLine()); !@3"vd{^
sHeader=httpConnection.getHeaderFieldKey(i); _`.Wib+
if(sHeader!=null) My<.^~
{ 2D)B%nM[
if(sHeader.equals("Content-Length")) 'B yB1NL
{ HP2J`>oo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !hWS%m@
break; IF'Tj`yD
} DrA\-G_7
} (j?ckah%V
else ;fe~PPT
break; B|SE |
} DA_}pS"
} wU(!fw\
catch(IOException e){e.printStackTrace ();} b>]k=zd
catch(Exception e){e.printStackTrace ();} p!>DA?vF
'@dk3:3t
C8t;E`
Utility.log(nFileLength); e82xBLxR%
=M9;`EmC
yIYQ.-DkS+
return nFileLength; _?v&\j
} 7&&3@96<*#
tE WolO[\
AjD?_DPc
//保存下载信息（文件指针位置） IN7Cpg~9%
private void write_nPos() P"f4`q
{ ,{2= nb[
try{ %sCG}? y
output = new DataOutputStream(new FileOutputStream(tmpFile)); {R8)DK
output.writeInt(nStartPos.length); sZPyEIXie
for(int i=0;i<nStartPos.length;i++) I/* ULR,
{ sT'j36Nc<,
// output.writeLong(nPos); 08G${@D+X0
output.writeLong(fileSplitterFetch.nStartPos); o@sL/5,
output.writeLong(fileSplitterFetch.nEndPos); #Q` TH<
} +vt?3i\^.
output.close(); {H3B1*Dk
} Pl\NzB,`
catch(IOException e){e.printStackTrace ();} Ruv`yfQ
catch(Exception e){e.printStackTrace ();} 21[=xboU
} d.yATP
T^Ol=QCu
# 11<=3Yj
//读取保存的下载信息（文件指针位置） t?wVh0gT
private void read_nPos() T/234;Uf|
{ yb6gYN
try{ XwIKpr8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @{{6Nd5
int nCount = input.readInt(); IoZ_zz0
nStartPos = new long[nCount]; bF'Jm*f
nEndPos = new long[nCount]; &}r-C97
for(int i=0;i<nStartPos.length;i++) S SfNI>
{ ,!dVhG#
nStartPos = input.readLong(); 3b[.s9Q
nEndPos = input.readLong(); 9#E)H?`g
} 089v; d 6
input.close(); mO2u9?N
} _%G;^ b
catch(IOException e){e.printStackTrace ();} ]Z?jo#F
catch(Exception e){e.printStackTrace ();} |j=Pj)5J
} W.BX6
?=G{2E.
aC94g7)`
private void processErrorCode(int nErrorCode) |7QSr!{_
{ bbT1p:RF
System.err.println("Error Code : " + nErrorCode); 0BQ{ZT-Kh
} B`)TRt+'.
fd$nAE
upnX7as
//停止文件下载 9[R+m3V/`
public void siteStop() [>KnMi=o)
{ CbwQbJ/v7
bStop = true; _+,>NJ
for(int i=0;i<nStartPos.length;i++) '^`iF,rg
fileSplitterFetch.splitterStop(); wZVLpF+7
qOv`&%txW
Jl<pWjkZZ
} P*n/qj8h
} ^l<!:SS
//负责部分文件的抓取 0#CmB4!<O
**FileSplitterFetch.java pS2u&Y"u|
*/ $[oRbH8g
package NetFox; Mm;[f'{M)
\5}*;O@
VTwQD"oB
import java.io.*; !j%uwje\
import java.net.*; iJ`zWpj+{Q
tz5\O}
CB#B!;I8v
public class FileSplitterFetch extends Thread { ]k8f1F
<}T7;knO
B(f_~]
String sURL; //File URL +j %y#_~
long nStartPos; //File Snippet Start Position kbo9nY1k g
long nEndPos; //File Snippet End Position Hb/8X !=
int nThreadID; //Thread's ID nk;^sq4M:
boolean bDownOver = false; //Downing is over iBwM]Eyv.
boolean bStop = false; //Stop identical r uIgoB
FileAccessI fileAccessI = null; //File Access interface J9MAnYd)i
(3~^zwA
Lp(i&A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I4KE@H"%7
{ NFF!g]QN
this.sURL = sURL; Z/T(4
this.nStartPos = nStart; tSe[*V4{'
this.nEndPos = nEnd; |h&Z.
nThreadID = id; kj6H+@ {
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xIwILY|W=
} AiB]A}
virt[5w
yy+:x/(N[
public void run() &*745,e
{ WrS>^\:
while(nStartPos < nEndPos && !bStop) ra2{8 x
{ zI\+]U'
ksTK'7*
34Cnbtq^
try{ |AT`(71
URL url = new URL(sURL); ;/t~MH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0Y:)$h2?
httpConnection.setRequestProperty("User-Agent","NetFox"); GG"6O_
String sProperty = "bytes="+nStartPos+"-"; `:C2Cj
httpConnection.setRequestProperty("RANGE",sProperty); Fy0sn|
Utility.log(sProperty); "l hj1zZ
M|Nh(kvH
9kB R/{
InputStream input = httpConnection.getInputStream(); |o+*Iy)
//logResponseHead(httpConnection); `sDLxgwI
2j#Dwa(lZQ
UB+7]S
byte[] b = new byte[1024]; @AM11v\:
int nRead; F`GXho[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *tv\5KW G
{ r*dNta<
nStartPos += fileAccessI.write(b,0,nRead); wWSo+40
//if(nThreadID == 1) )U7fPKQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1wm`a
} /='Q-`?9
hC9EL= A
?z2!?
Utility.log("Thread " + nThreadID + " is over!"); BMqr YW
bDownOver = true; wa~zb!y<
//nPos = fileAccessI.write (b,0,nRead); /]U;7)
} =z]rZSq*o
catch(Exception e){e.printStackTrace ();} &H P g>
} t2YB(6w+xg
} ens]?,`0
t\}_WygN
<EQaYZY=
//打印回应的头信息 d!4TwpIgx
public void logResponseHead(HttpURLConnection con) (z8;J>7
{ QBGjH^kL
for(int i=1;;i++) I~^Xw7
{ bt(Y@3;
String header=con.getHeaderFieldKey(i); )EQz9
if(header!=null) v~yw-}fk%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H^54o$5
Utility.log(header+" : "+con.getHeaderField(header)); w/"vf3}(9
else \.}ZvM$
break; %H;}+U]Z
} 8a&c=9
} |a a\t
K&RIF]0#G
JWYe~
public void splitterStop() cy)-Rfg
{ ![nL/
bStop = true; S;jD@j\t&
} #p7gg61
1X7GM65#
tC(MaI
} : p)R,('g
ij!],
5!cp^[rGL
/* }2;iIw`
**FileAccess.java <:NahxIlu
*//文件访问(定位，写) B-$?5Ft!
package NetFox; %l14K_
import java.io.*; *v]s&$WyO
[ZC\8tP`V
ZNM9@;7
public class FileAccessI implements Serializable{ |TP,
TET=>6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lM}-'8tt?
RandomAccessFile oSavedFile; iF":c}$.
long nPos; /H"fycZ
)Tp"l"(G
09trFj$L
public FileAccessI() throws IOException 7(uz*~Z?`0
{ dP+wcl4
this("",0); DB65vM
} ,|3_@tUl
_p5#`-%mM
5S2 j5M00
public FileAccessI(String sName,long nPos) throws IOException ]z5hTY
{ ~*"ZF-c,
oSavedFile = new RandomAccessFile(sName,"rw"); C:}1r
this.nPos = nPos; HA,8O[jon
oSavedFile.seek(nPos); RgUQ:
} ~[dL:=?c
}A,!|m4
KvEv0L<ky
public synchronized int write(byte[] b,int nStart,int nLen) ZSW@,Ti
{ c"-X:m"
int n = -1; Maq`Or|4
try{ L+p}%!g
oSavedFile.write(b,nStart,nLen); Y]KHCY
n = nLen; `e~i<Pi
} n6.Z{Q'b
catch(IOException e) ZSwuEX
{ F'OO{nF
e.printStackTrace (); o $W@@aM
} (H&HSs
y<w_>O
uR{)%udu
return n; -gk2$P-
} VFx[{Hy
li v=q
/*{'p!?
} |>.MH
}e/vKWfT
`4snTM!v&
/* 2>o^@4PnZ
**SiteInfoBean.java VevG 64o
*/ K-)!d$$
package NetFox; gd]S;<Jh
HcJ!(
Q~qM;l\i
public class SiteInfoBean { pfHjs3A=
y<j7iN
wK7w[Xt
private String sSiteURL; //Site's URL m$^5{qpg
private String sFilePath; //Saved File's Path q~ ZUtF
private String sFileName; //Saved File's Name A{J?I:
private int nSplitter; //Count of Splited Downloading File ?d%{-
=X^a
_u^3uzu
public SiteInfoBean() |h6!bt!=
{//nSplitter的缺省值为5 vA!IcDP"
//default value of nSplitter is 5 D (8Z90
this("","","",5); 4'*-[TKC
} 3<+ZA-2
V0Oqq0\
}BU%<5CQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6vAZLNG3
{ X/cb1#
sSiteURL= sURL; hU-FSdR
sFilePath = sPath; !reOYt|
sFileName = sName; Hzm_o>^KC
this.nSplitter = nSpiltter; Uq_lT,
cZ|NGkZ
ga/zt-&
} z9 Ch %A{
~cSXBc,+
3^%2,
public String getSSiteURL() ,7bhUE/VB
{ %L-qAI&V
return sSiteURL; /CO=!*7fz
} FXDB> }8
hZ452W
Y:O|6%00Y
public void setSSiteURL(String value) %a WRXW@c
{ %LP4RZ
sSiteURL = value; , +J)`+pJx
} IB|6\uKn
DJ<+" .v!
.O'~s/h
public String getSFilePath() {[tmz;C
{ yP# Y:s
return sFilePath; ]s0wJD=
} zps=~|
SyI~iW#Y1
\By_mw
public void setSFilePath(String value) mY/"rm
{ <(@S;?ZEW
sFilePath = value; 8Cp@k=
} 5NUaXQ
O2ktqAWx@
N,rd= m+
public String getSFileName() 3{|~'5*
{ 1!G}*38;
return sFileName; HQ9tvSc
} yOQae m^O
kN1R8|pv
"*D9.LyM
public void setSFileName(String value) {+_p?8X
{ g$#A'Du
sFileName = value; "Y L^j~A
} t?-a JU
d3q.i5']G
Qd YYWD
public int getNSplitter() =cS5f#0
{ "GZ}+K*GG
return nSplitter; %V]v,
} sV2D:%\K:
L5 Cfa-
5PZ7-WJ/
public void setNSplitter(int nCount) )'f=!'X
{ -r<8mL:yW
nSplitter = nCount; y*X.DS 1(w
} 6>#8^{[
} WHBGhU
"Hz%0zP&
$`W3`}#fM
/* }"WovU{*s
**Utility.java K;"oK
*/ 0LL65[
package NetFox; V6[jhdb
qGH[kd
)@I] Rk?
public class Utility { 9y&;6V.'
Xw'sh#i2
$8U$.~v
public Utility() m-\_L=QzM
{ 4(P<'FK $
v{|y,h&]a
CSoVB[vS
} ww7nQ}H5(
rQ_cH
//线程睡眠 3bezYk
public static void sleep(int nSecond) )8g&lyT
{ 2;>uP#1]
try{ h%u!UHA
Thread.sleep(nSecond); GqsV6kH
} Z7pX%nj_
catch(Exception e) 5EQ)pH+
{ CQ.C{
e.printStackTrace (); e8dZR3JL
} ^&86VBP
} E"p _!!1
H/M]YUs/3
//日志 p<'pqf
public static void log(String sMsg) k"gm;,`
{ -f ~1Id
System.err.println(sMsg); "#gKI/[qxq
} QnBWZUI
&F:.V$
ob/<;SrU<
public static void log(int sMsg) @.a59kP8X
{ J`0dF<<{[y
System.err.println(sMsg); ZDzG8E0Sq
} r vq{Dfo=
} >gL&a#<S
.!L{yU,
qvo!nr7
/* HxW/t7Z(
**TestMethod.java (_FeX22+
*/ RAu(FJ
package NetFox; 6(7{|iY
Q%q;=a
hG~.Sc:G
public class TestMethod { (-0d@eqw
q({-C
Tf!6N<dRXR
public TestMethod() ltkARc3
{ ///xx/weblogic60b2_win.exe :d35?[
try{ #W/Ch"Kv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <m~8pM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q%q+2P>
SiteFileFetch fileFetch = new SiteFileFetch(bean); LqI&1$#
fileFetch.start(); N-2_kjb!
} Bf y
catch(Exception e){e.printStackTrace ();} A#?Cts,M
0Cf'\2
S2|pn\0V
} V\L%*6O
73S N\
eB9&HD:
public static void main(String[] args) zBq&/?
{ A7#nBHwxZ
new TestMethod(); ucz~y!4L{
} vJi<PQ6
} WQN`y>1#@_
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