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)); s%m?Yh3
} |="Y3}a
for(int i=0;i<nEndPos.length-1;i++) .\)ek[?
{ B <HD
nEndPos = nStartPos[i+1]; {n<1uh9~$8
} \9sJ`,T?
nEndPos[nEndPos.length-1] = nFileLength; xyXVWd[
} l~@ -oE
} \!0~$?_)P
n2["Ln mO
'k<~HQr
//启动子线程 \TYH7wXDP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g`"_+x'
for(int i=0;i<nStartPos.length;i++) mhs%8OTN
{ C [8='i26
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ? fM_Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7L]Y.7>
nStartPos,nEndPos,i); [LbCG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ro2!$[P
fileSplitterFetch.start(); )M56vyo
} `#j;\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u1Wixjd|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :<1PCX2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =RlAOgJ
nEndPos = " + nFileLength); gA2]kZg
// fileSplitterFetch[nPos.length-1].start(); )S@TYzdAN
'm/`= QX
j<w5xY
//等待子线程结束 _sCzee&uQ
//int count = 0; mP_c-qD |
//是否结束while循环 iTCY $)J
boolean breakWhile = false; P Qi=
o'YK\L!p
8`WaUB%
while(!bStop) 1t#|MH ?U_
{ C33RXt$X
write_nPos(); ZM57(D
Utility.sleep(500); 0!1cHB/c
breakWhile = true; 5hlS2fn
N_VWA.JHt
-e*(+
for(int i=0;i<nStartPos.length;i++) - KaU@t
{ LD}<|
if(!fileSplitterFetch.bDownOver) ovvg"/>L
{ 7X.B
breakWhile = false; ]; B`'Ia
break; M-C>I;a
} 5F1P|t#
} zZPXI&,
if(breakWhile) AUr~b3< 6
break; u#$sO;8s
]"\sd"
Cs^'g'
//count++; w?R#ly
//if(count>4) aR%E"P-6l
// siteStop(); QY1|:(
} "^VPe[lA
(;++a9GK
!L@a;L
System.err.println("文件下载结束！"); *1U"uJno
} qtS+01o
catch(Exception e){e.printStackTrace ();} HQ/ Q"
} 2>kk6=<5'
T2XLP
l-6W]\v Z
//获得文件长度 s{0c.M
public long getFileSize() XILreATK@
{ |'Ksy{lA
int nFileLength = -1; nh/%0=S
try{ _%PEv{H0.
URL url = new URL(siteInfoBean.getSSiteURL()); TK Ec^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l3YS_WBSn
httpConnection.setRequestProperty("User-Agent","NetFox"); OH`|aqN
zj#8@gbh+
c7 O$< F
int responseCode=httpConnection.getResponseCode(); #pWeMt'
if(responseCode>=400) JP6+h>ft
{ cGv`%
processErrorCode(responseCode); -Dr)+Y
return -2; //-2 represent access is error aq.Lnbi/X
} +^|=MK%
Iv>4o~t
1&utf0TX6q
String sHeader; .J2tm2]"EZ
~s) `y2Y
<USr$
for(int i=1;;i++) z_t%n<OvK
{ Q;2n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |@pn=wW
//Utility.log(in.readLine()); [^\HP]*Q{
sHeader=httpConnection.getHeaderFieldKey(i); _4X3g%nXl
if(sHeader!=null) -AM(-
{ !u=A9i!
if(sHeader.equals("Content-Length")) Y i`wj^
{ aHSl_[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b|u0a6
break; q,.@<sW
} 42.y.LtZ
} t ;bU#THM
else <4D.H
break; .2QZe8"
} ~L=? F
} ge$p/
catch(IOException e){e.printStackTrace ();} k\}\>&Zqu
catch(Exception e){e.printStackTrace ();} n4DKLAl
ITBa ^P
^7V{nT@H3
Utility.log(nFileLength); M1e79p<
I{uwT5QT-
[Qn$i/`J
return nFileLength; c7t.
} Aiqn6BX{
G!5~`v
Tu}?Q.pKo
//保存下载信息（文件指针位置） =g$>]AE
private void write_nPos() }/.GB5Ej
{ 5<h:kZ"S^g
try{ ]E}eM@xdD
output = new DataOutputStream(new FileOutputStream(tmpFile)); "uG@gV
output.writeInt(nStartPos.length); qnTW?c9Z5
for(int i=0;i<nStartPos.length;i++) lVo}DFZ
{ Ag0)> PD^
// output.writeLong(nPos); &Q[|FO;[
output.writeLong(fileSplitterFetch.nStartPos); *n2le7
output.writeLong(fileSplitterFetch.nEndPos); ~zL DLr=
} 75*q^ui
output.close(); # 4;(^`?
} i'uSu8$'*
catch(IOException e){e.printStackTrace ();} vALH!Kh
catch(Exception e){e.printStackTrace ();} L31#v$;4
} x\'95qU
#A9rI;"XI
]O+W+h{]
//读取保存的下载信息（文件指针位置） EOzw&M];r
private void read_nPos() 2#xz,RM.
{ xA]}/*
try{ O <"\G!y~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |,WP)
int nCount = input.readInt(); ,*d<hBGbh
nStartPos = new long[nCount]; {*AYhZ
nEndPos = new long[nCount]; j5bp)U
for(int i=0;i<nStartPos.length;i++) "|<U`3y6
{ \'-E[xNcWI
nStartPos = input.readLong(); V8"m_
nEndPos = input.readLong(); 5PPaR|c3
} 2rG$.cGN"
input.close(); X.J$ 5b
} t-VU&.Y
catch(IOException e){e.printStackTrace ();} whh#J (
catch(Exception e){e.printStackTrace ();} @Avve8S
} &a?k1R>
GVUZn//
T1g3`7C3
private void processErrorCode(int nErrorCode) lkaWwjv_D
{ UA(&_-C\
System.err.println("Error Code : " + nErrorCode); F`RPXY`ux
} LV`tnt's
4s7&*dJ
s1%th"e [
//停止文件下载 O("13cU
public void siteStop() /DoSU>%hK
{ 91ndr@*|
bStop = true; c^x5 E`{
for(int i=0;i<nStartPos.length;i++) @"O|[%7e
fileSplitterFetch.splitterStop(); gfly?)VnF
]Wx?k7T
ytyB:# J
} ],l\HHQ
} } @4by<
//负责部分文件的抓取 Oe"nNvu/
**FileSplitterFetch.java (svKq(X
*/ H_d^Xk QZ
package NetFox; Rh#QPYPq
M992XXd
ZXC_kmBN/
import java.io.*; k8E{pc6;
import java.net.*; hK 1 H'~c
Tga%-xr+
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public class FileSplitterFetch extends Thread { BKk+<#Ti
s%i \z }/
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String sURL; //File URL LW!>_~g-
long nStartPos; //File Snippet Start Position %abc-q
long nEndPos; //File Snippet End Position v?(z4oOD/>
int nThreadID; //Thread's ID (DY&{vudF
boolean bDownOver = false; //Downing is over ]\(Ho
boolean bStop = false; //Stop identical \/F*JPhy
FileAccessI fileAccessI = null; //File Access interface XWag+K
L*(`ccU
^"] ]rZ)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yyM`J7]J
{ Fuy"JmeR
this.sURL = sURL; $nr=4'yZ
this.nStartPos = nStart; j]J-#J
this.nEndPos = nEnd; m"GgaH3,
nThreadID = id; tui5?\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Hd57Iw
} L'u*WHj|v
,Rdw]O
!24PJ\~I
public void run() o^v]d7I8b
{ Nj=0bg"Qg5
while(nStartPos < nEndPos && !bStop) z^u*e
{ p9![8VU
cyBm,!
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try{ -S7i':
URL url = new URL(sURL); KpC!C9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Of m0{c=
httpConnection.setRequestProperty("User-Agent","NetFox"); @ )Nw>/;o
String sProperty = "bytes="+nStartPos+"-"; `wKd##v'@
httpConnection.setRequestProperty("RANGE",sProperty); 6o&ZS @
Utility.log(sProperty); `APeS=< &
cy0j>-z
VWrb`p@
InputStream input = httpConnection.getInputStream(); mv>-XJ+
//logResponseHead(httpConnection); <RuLIu
{'sp8:$a
%\T#Ik~3
byte[] b = new byte[1024]; 5O[\gd-
int nRead; #@L5yy2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1|:'jK#gE
{ ~(\.j=x
nStartPos += fileAccessI.write(b,0,nRead); B["jndyr
//if(nThreadID == 1) ca<OG;R^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'Lh nl3
} 6'Q*SO;1gh
lQ&J2H<w
&Gs/#2XQ
Utility.log("Thread " + nThreadID + " is over!"); ~rlPS#]o
bDownOver = true; !GnwE
//nPos = fileAccessI.write (b,0,nRead); 1>L8EImx]V
} Dg*'n
catch(Exception e){e.printStackTrace ();} QYc/f"9
} W:hTRq
} 2`J#)f|
lUd4`r"
[*1:?mD$
//打印回应的头信息 M)3'\x:
public void logResponseHead(HttpURLConnection con) `#4q7v~>oe
{ 'm0_pM1:D
for(int i=1;;i++) y+h/jEbM</
{ Yf_/c*t\5
String header=con.getHeaderFieldKey(i); -J>f,zA
if(header!=null) p^ ONJL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o_a'<7\#i
Utility.log(header+" : "+con.getHeaderField(header)); |k#EYf#Y
else pgPm0+N
break; S 9|^VU
} MavidkS
} \%_sL#?
b%7zu}F
N?IdaVLj
public void splitterStop() wRg[Mu,Q5
{ ^O<@I
bStop = true; iy|;xBI,
} eOahr:Db
1BSn#Dnj
Vi#[kn'
} wb ^>/
6Ev+!!znu
5xQ5)B4k
/* WO$8j2!~#
**FileAccess.java F`>qg2wO
*//文件访问(定位，写) ?}HZJ@:lB
package NetFox; G"ixw
import java.io.*; #'. '|z
q8MyEoc:n
\+Y5b}
public class FileAccessI implements Serializable{ <?h(Dchq
1n[wk'}qf4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a:s$[+'Y
RandomAccessFile oSavedFile; @6*eS+t\
long nPos; 3zv0Nwb,
*;T'=u_lR
f#-\*
public FileAccessI() throws IOException B<ZCuVWH:
{ D;z!C ys
this("",0); 9{0%M
} u qA!#E
zXk^ugFy
/ 2MhP=,
public FileAccessI(String sName,long nPos) throws IOException WBR# Ux
{ #<G:&
oSavedFile = new RandomAccessFile(sName,"rw"); ,{_56j^d,
this.nPos = nPos; -`$J& YU
oSavedFile.seek(nPos); }!"Cvu
} 89t"2|9 u
/Mj|Px%
2fXwJG'
public synchronized int write(byte[] b,int nStart,int nLen) 8! /ue.T
{ {\X$vaF
int n = -1; TN<"X :x9
try{ 0^)~p{Zh
oSavedFile.write(b,nStart,nLen); Jl|^^?
n = nLen; G?!8T91;
} *+(eH#_2/
catch(IOException e) .g94|P
{ _#we1m
e.printStackTrace (); S5r.so
} [E/. r{S
eN`G2eE
v1/Y0
return n; i=&]%T6Qk
} )1 QOA
9A87vs4[
/S@iF
} r.c:QY$
;p87^:
x6ayFq=
/* k1SD{BL
**SiteInfoBean.java ?)Je%H
*/ 7>F[7_
package NetFox; .3#Xjhebvu
) )t]5Ys%;
%'VzN3Q5V
public class SiteInfoBean { J&B5Ll
I9xkqj
?!.J0q
private String sSiteURL; //Site's URL bdEIvf7
private String sFilePath; //Saved File's Path lqa~ZF*
private String sFileName; //Saved File's Name yqR]9"a
private int nSplitter; //Count of Splited Downloading File mQ9shdvt-
'T7Y5X80$j
<9c{Kt.5(
public SiteInfoBean() wk'&n^_br
{//nSplitter的缺省值为5 d. ZfK
//default value of nSplitter is 5 L-zU%`1{M
this("","","",5); $LcMG,8%_
} b1G6'~U-
'&$zgK9T?
9W-1P}e,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8"p rWAN
{ |:,`dQfw
sSiteURL= sURL; 1H-~+lf
sFilePath = sPath; N#@v`S
sFileName = sName; '8FHn~F
this.nSplitter = nSpiltter; .v-2A);I
r]]:/pw?t
BK wo2=m~
} s'OK])>`
L(9AcP
(*,R21<%
public String getSSiteURL() e_g&L)
{ GkI{7GD:z
return sSiteURL; s(e1kk}"
} =#A/d`2 b
@Kw&XKe`
D *IeG>%
public void setSSiteURL(String value) L+eK)Q
{ @ZrNV*&<
sSiteURL = value; |C5{[ z
} JY,oXA6O
FlY"OU*
2fNNdxdbT
public String getSFilePath() HrMbp
{ ly6dl
return sFilePath; [Dmf.PUe
} fwh/#V-i
R<%{I)
F&B E+b/#
public void setSFilePath(String value) m=Mk@xfQ#
{ y=jZ8+M
sFilePath = value; =@q,/FR-
} UMT}2d%
B\l0kiNT
zMM~4?4
public String getSFileName() .u`A4;;Gw
{ {xOzxLB;
return sFileName; }SyK)W5Y
} i6y=3k
e@S\7Ks
q8,,[R_
public void setSFileName(String value) k~F,n
{ *I}_g4
sFileName = value; hS>=pO+y
} Qstd;qE~
ln":j?`
M(uJ'Ud/!
public int getNSplitter() 73_-7'^mQ
{ ;e9&WEG_\
return nSplitter; 0-57_";%Q
} zQUNvPYM
P"Z1K5>2L
g@pK9R%wH<
public void setNSplitter(int nCount) 2=%]Ax"R
{ fhNJB0
nSplitter = nCount; !89hO4 0r
} gvL*]U7
} -KfMKN~
Og8%SnEpMI
JXR]G
/* 1/6}E]-F
**Utility.java DF-.|-^9I
*/ B}K<L\S
package NetFox; J,s:CBCGL
FMzG6nrdBN
" BLJh)i
public class Utility { NbCIL8f]
P m&^rC;
5H|7DVG
public Utility() =WEDQ\ c
{ `.]oH1\
nT(AO-Ue^
I1s$\NZ~]
} lhf5[Rp
l)'*jZ
//线程睡眠 QIJ/'72
public static void sleep(int nSecond) i [Wxu M
{ {XD':2E
try{ D=Yr/qc?
Thread.sleep(nSecond); rV?@Kgxi
} +8"P*z,
catch(Exception e) bQPO'S4
{ (m=1yj9
e.printStackTrace (); -rT#Wi
} 2^nws
} ][YuJUK8
Der'45]*^
//日志 mX?t|:[b
public static void log(String sMsg) txQr|\4k
{ B(O6qWsL
System.err.println(sMsg); x5rLGt
} 4Y4zBD=<
@RL'pKab9
-8dz`o}
public static void log(int sMsg) +rhBC V
{ K}GRU)
System.err.println(sMsg); AsvH@\\
} AVfF<E/
} F IB)cpo
Y]5MM:mI
`)MKCw$e
/* fvV"H{V,
**TestMethod.java >;VZB/d
*/ uyWw3>
package NetFox; rhly.f7N=A
{+3g*s/HI
(.L?sDQ</z
public class TestMethod { ] ;CJ6gM~
_A0X[}^K
MD3iWgM
public TestMethod() c6y>]8_
{ ///xx/weblogic60b2_win.exe `O;4b#!g
try{ 5g$>J)Ry
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %az6\"n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xO,;4uE
SiteFileFetch fileFetch = new SiteFileFetch(bean); mZuLwd$0
fileFetch.start(); e"*ho[
} Pv3G?u=4
catch(Exception e){e.printStackTrace ();} Lw1[)Vk}E
(Jk[%_b>_
8#o2qQ2+
} [,MK)7DU
6':Egh[;
pF8+< T3y
public static void main(String[] args) N.ZuSkRM
{ 2"%f:?xV{
new TestMethod(); /<%L&
} SZ7; } r8
} ]mgpd}Y
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