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)); xyxy`qRA
} @(lh%@hO
for(int i=0;i<nEndPos.length-1;i++) l+b~KU7~l
{ |vC~HJpuv'
nEndPos = nStartPos[i+1]; {.]7!ISl5
} 2KZneS`
nEndPos[nEndPos.length-1] = nFileLength; ;FEqe49
} [fyLV`
} K)P%;X
!@"OB~
rZpXPI
//启动子线程 3(UVg!t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %}T6]S)%u
for(int i=0;i<nStartPos.length;i++) uw8f ~:LT
{ !`r$"}g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )M^ gT}M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]_$[8#kg
nStartPos,nEndPos,i); p]"4#q\(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &e3.:[~_?
fileSplitterFetch.start(); &nK<:^n
} qJw_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y_[vr:s5pG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ")25 qZae
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S|}L&A
nEndPos = " + nFileLength); AOx[
// fileSplitterFetch[nPos.length-1].start(); i-&yH
t`QENXA}
Bbp|!+KP{(
//等待子线程结束 q cno^8R
//int count = 0; LH6vLuf
//是否结束while循环 }PpUAt~g
boolean breakWhile = false; _ x*3PE
>R=|Wo`Ri
Mb=" Te>|
while(!bStop) fXB0j;A
{ Vw"\{`
write_nPos(); tf G@&&%9
Utility.sleep(500); fc@A0Hf
breakWhile = true; 13wE"-
048kPXm`
DV{=n C
for(int i=0;i<nStartPos.length;i++) M^I(OuRMeI
{ hv+zGID7
if(!fileSplitterFetch.bDownOver) PI<vxjOK`
{ [/ZO q
breakWhile = false; :hA#m[
break; ~)'k 9?0
} Q@HV- (A
} Y\tui+?J
if(breakWhile) !&\INl-Z
break; tnIX:6
g=I})s:CTp
|cY`x(?yP
//count++; GKCroyor
//if(count>4) 2"~8Z(0
// siteStop(); \j.:3Xr
} tg/H2p^Y
F1hHe<)
h7@6T+#WoT
System.err.println("文件下载结束！"); g `4<9RMun
} mVmGg,
catch(Exception e){e.printStackTrace ();} jFb?b6b
} !o-@&q
YbLW/E\T
$ulOp;~A%
//获得文件长度 L=h'Qgk%
public long getFileSize() .sA.C]f
{ 'ig'cRD6N
int nFileLength = -1; hzC>~Ub5
try{ PRT +mT
URL url = new URL(siteInfoBean.getSSiteURL()); SY8C4vb'h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CH/rp4NeSy
httpConnection.setRequestProperty("User-Agent","NetFox"); ^W@5TkkBQq
8$|=P!7EO
A70d\i
int responseCode=httpConnection.getResponseCode(); F<w/PMb
if(responseCode>=400) y!%CffF2
{ LIdF 0
processErrorCode(responseCode); s(8W_4&'
return -2; //-2 represent access is error :i7;w%B
} ]N[ 5q=A5
GH xp7H
*owU)
String sHeader; |D.ND%K&
;=UsAB]
&-=5Xc+Z
for(int i=1;;i++) {_dvx*M
{ U%<Inb}ad
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WN<zkM~3
//Utility.log(in.readLine()); QdC<Sk!G
sHeader=httpConnection.getHeaderFieldKey(i); a}uSm/S
if(sHeader!=null) .[ mRM
{ *9i{,I@
if(sHeader.equals("Content-Length")) |WUG}G")*x
{ s9d_GhT%-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L_s:l9!r
break; uwBiW
} v9UD%@tZ
} #o2[hibq
else ~v"L!=~G;a
break; FCn_^l)EA
} K4);HJ|=
} w`=\5Oa.G
catch(IOException e){e.printStackTrace ();} MJrR[h]
catch(Exception e){e.printStackTrace ();} 'P}0FktP`
.>nRzgo
8sCv]|cn
Utility.log(nFileLength); sT' 5%4
]0\MmAJRn
VD\=`r)nT
return nFileLength; t()c=8qF|u
} A+)`ZTuO
v9->nVc-
F}qc0
//保存下载信息（文件指针位置） Hq 188<
private void write_nPos() T,tdL N-
{ j8`BdKg
try{ YrKWA
output = new DataOutputStream(new FileOutputStream(tmpFile)); -PQv ?5
output.writeInt(nStartPos.length); $tS}LN_!
for(int i=0;i<nStartPos.length;i++) 9&ids!W~yx
{ I!?}jo3
// output.writeLong(nPos); 40<mrVl
output.writeLong(fileSplitterFetch.nStartPos); _/K_[w 1
output.writeLong(fileSplitterFetch.nEndPos); PiYxk+N
} 1sH& sGy7
output.close(); e 3TI|e_
} &8 x-o,
catch(IOException e){e.printStackTrace ();} BVO<e \>3
catch(Exception e){e.printStackTrace ();} vZoaT|3 G]
} w1DV\Ap*
}>X~
O1mKe%'|
//读取保存的下载信息（文件指针位置） L,@lp
private void read_nPos() xZv#Es%#
{ ?3xzd P
try{ F@:'J\I}:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DDH:)=;z
int nCount = input.readInt(); VM,]X.
nStartPos = new long[nCount]; !GGkdg*-*9
nEndPos = new long[nCount]; 8ITdSg
for(int i=0;i<nStartPos.length;i++) #YOA`m,'
{ E\,-XH
nStartPos = input.readLong(); 1y4
nEndPos = input.readLong(); ^`>/.gL
} 0_t`%l=
input.close(); 8*T=Xei8
} *`RkTcG
catch(IOException e){e.printStackTrace ();} `^y7f
catch(Exception e){e.printStackTrace ();} {> 0wiH#!E
} (ICd}
\;"=QmRD%:
f`=-US
private void processErrorCode(int nErrorCode) \} :PLCKT
{ %1$,Vs<RH
System.err.println("Error Code : " + nErrorCode); > "=>3
} HoL Et8Q
3kMf!VL
;BIY^6,7e
//停止文件下载 .h4 \Y A
public void siteStop() w:Kl6"c
{ q#=(e:aCb
bStop = true; 5N&?KA-
for(int i=0;i<nStartPos.length;i++) J~UuS+Ufv
fileSplitterFetch.splitterStop(); Tyf`j,=
Eg3q!J&Z
C-[eaHJ'$
} 'ub@]ru|
} $'hEz/
//负责部分文件的抓取 :A'y+MnK<
**FileSplitterFetch.java ';=O 0)u
*/ '(L7;+E
package NetFox; [mGLcg6Fw
M1iS(x
8eHyL
import java.io.*; s6^>F/x
import java.net.*; }d}Ke_Q0
vTzlwK\#1
$@"g^,n
public class FileSplitterFetch extends Thread { ^RtIh-Z.9
RuVGG)
<3C*Z"aQ>|
String sURL; //File URL ^qD$z=z-
long nStartPos; //File Snippet Start Position cq/$N
long nEndPos; //File Snippet End Position Y\?"WGL)p
int nThreadID; //Thread's ID FE|JHh$
boolean bDownOver = false; //Downing is over @wNG{Stj
boolean bStop = false; //Stop identical 6MMOf\
FileAccessI fileAccessI = null; //File Access interface BeoDKdAwY
JHTSUq
-0x #
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oEKvl3Hz_
{ wyO4Y
this.sURL = sURL; xRLT=.ir
this.nStartPos = nStart; 'Xq|Kf (
this.nEndPos = nEnd; 'op|B@y
nThreadID = id; 8i#2d1O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~<F8ug#
} ^N{h3b8
GH:jH]u!V
DjQFi
public void run() T&u5ki4NE
{ V7fq4O^:
while(nStartPos < nEndPos && !bStop) 7/@TF/V
{ \B,@`dw
.jT#:_
CxOob1@
try{ ;LSANr&
URL url = new URL(sURL); 8_B4?` k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d K3*;
httpConnection.setRequestProperty("User-Agent","NetFox"); hVAn>_(
String sProperty = "bytes="+nStartPos+"-"; Q%tXQP.r
httpConnection.setRequestProperty("RANGE",sProperty); Eq9x2
Utility.log(sProperty); 3/e.38m|
V/ uP%'cd
vJc-6EO
InputStream input = httpConnection.getInputStream(); PB`Y g
//logResponseHead(httpConnection); MSqVlj
n QZwC
}1i`6`y1
byte[] b = new byte[1024]; Tg)|or/%
int nRead; [KaAXv .X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &LZn FR
{ qqr?!vem6
nStartPos += fileAccessI.write(b,0,nRead); u^bidd6JRn
//if(nThreadID == 1) # 0Q]dO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~{B7 k:
} bj0G5dc=
A_ N;
ZC`wO%,
Utility.log("Thread " + nThreadID + " is over!"); \[_t]'p
bDownOver = true; a /l)qB#
//nPos = fileAccessI.write (b,0,nRead); 0s3%Kqi[
} >#~& -3
catch(Exception e){e.printStackTrace ();} _w(7u(Z
} R0]1xGz
} (\hx` Yh=>
i8[t=6Rm@
0gy/:T
//打印回应的头信息 %D}kD6=
public void logResponseHead(HttpURLConnection con) aweV#j(y
{ {V$|3m>:*
for(int i=1;;i++) D4-ifsP
{ JG!mc7
String header=con.getHeaderFieldKey(i); Cc' 37~6~P
if(header!=null) 8\ +T8(m
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G"U9E5O
Utility.log(header+" : "+con.getHeaderField(header)); 7>Ouqxh21
else K'Tm_"[u
break; kmsb hYM)
} I{9QeRI
} &5spTMw8
O-~7b(Z
&<5zqsNJ\a
public void splitterStop() wh\}d4gN
{ Ng>5?F^v
bStop = true; YY((V@|K
} 7BjJhs
(Hz^)5(~
ZaDyg"Tw+
} )oDHeU<&
zRl3KjET
'}JhzKNj
/* X!Mx5fg
**FileAccess.java B=yqW
*//文件访问(定位，写) N^ds RYC
package NetFox; V>)OpvoT#
import java.io.*; t?ZI".>
^ft>@=K(|
m!4ndO;0vh
public class FileAccessI implements Serializable{ fc%xS7&
uK#4(eY=W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '(VJ&UlS2
RandomAccessFile oSavedFile; Y. 5_6'Eo?
long nPos; gsvuE
a 3b/e8c
Lh"<XYY
public FileAccessI() throws IOException f/NH:1)y
{ iNz=e=+Si
this("",0); 3n1;G8Nf
} }~jlj
1N^[.=
z8~NZ;A
public FileAccessI(String sName,long nPos) throws IOException #`iB`|
{ +p_CN*10H
oSavedFile = new RandomAccessFile(sName,"rw"); I^]2K0+x x
this.nPos = nPos; yw[g!W
oSavedFile.seek(nPos); NP#w+Qw
} z^q0/'
YTpSHpf@
TJpD{p}
public synchronized int write(byte[] b,int nStart,int nLen) Ic:(Gi- %
{ dvx#q5f_S
int n = -1; }DEg-j,F
try{ WZejp}x
oSavedFile.write(b,nStart,nLen); e7r-R3_
n = nLen; 9ni1f{k
} C'@i/+
catch(IOException e) Ae^~Cz1qz
{ 3!Ij;$
e.printStackTrace (); tr3!d_
} ?|C2*?hZ+
%lx!.G
ZW8vza
return n; Y3cMC)
} };bEU wGWf
vq0Tk bzs
ksqQM
} 9y8&9<#
Mj?`j_X
g i-$ZFzB
/* 4*#18<u5
**SiteInfoBean.java qI9z;_,gNz
*/ K5VWt)Z#
package NetFox; m6K}|j
_LUhZlw
K.nHii
public class SiteInfoBean { ,RI Gc US
Y>T-af49
8f4b&ah
private String sSiteURL; //Site's URL 4Zddw0|2
private String sFilePath; //Saved File's Path LTCb@L{^i
private String sFileName; //Saved File's Name ~&_z2|UXp
private int nSplitter; //Count of Splited Downloading File T_ <@..C
d-ZJL6-
@|m/djN5x
public SiteInfoBean() oUr66a/[U
{//nSplitter的缺省值为5 f4b/NG|
//default value of nSplitter is 5 $q{!5-e
this("","","",5); _QE qk@ql
} x7w4[QYw
")5":V~fN
Al^d$FaF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J26VnK
{ {n.PF8A5X
sSiteURL= sURL; :$|HNeDO
sFilePath = sPath; 7\[@m3s
sFileName = sName; M}-Rzc
this.nSplitter = nSpiltter; |?xN\O^#}
t%FwXaO#
G]tn i
} SrJGTuXg
^Za-`8#`L
o#gWbAG;]b
public String getSSiteURL() |\t-g"~sN
{ 7~p@0)''
return sSiteURL; b<ZIWfs
} PO^ij2eS
'<xXK@=KEI
"ycJ:Xv49
public void setSSiteURL(String value) 2r4Uh1D~
{ 6=/F$|
sSiteURL = value; mb3"U"ohs
} -p-ZzgQ
cn3\kT*
'n]w"]|
public String getSFilePath() jo@6?( *4
{ F6|]4H.3Q
return sFilePath; 1D7`YKI9h
} [Ek7b*
M `M5'f
ZzpUUH/r
public void setSFilePath(String value) :#ik. D
{ ^|>PA:%
sFilePath = value; n\D&!y[]F
} 5` ~JPt
IdYt\^@>
RJ&RTo
public String getSFileName() xn(kKB.
{ ?4&e;83_#y
return sFileName; vWv"
} rfJz8uF%
$6 9&O
,Vm < rK
public void setSFileName(String value) hH3RP{'=
{ {9pZ)tB
sFileName = value; c_pr
} UHkMn
! E5HN :#
Lv7(st%`
public int getNSplitter() 3M7/?TMw{6
{ Tv=mgH=b
return nSplitter; uyWunpT
} 2- h{N
qgHWUwr+n
AKfDXy
public void setNSplitter(int nCount) ((;!<5-`s
{ Eyqa?$R
nSplitter = nCount; C2I_%nU Z1
} b\!_cb~"@
} $( kF#
]:-mbgW
0i>5<ej,f
/* k%#EEMh
**Utility.java "Gzz4D
*/ lgy<?LI\
package NetFox; @Uvz8*b6
tSUEZ62EY
'GWN~5
public class Utility { b. '-?Nn
P3=G1=47U
MJO-q $)c
public Utility() ksUcx4;a@F
{ -d/ =5yxL
d&Zpkbh"
yx[/|nZDC4
} 7xlkZF
Mb}QD~=M
//线程睡眠 8kIksy
public static void sleep(int nSecond) 1R%.p7@5QU
{ Pmx-8w
try{ )2o?#8J
Thread.sleep(nSecond); O8r|8]o
} pah'>dAL
catch(Exception e) t!l&iVWs
{ ^[`%&uj!g
e.printStackTrace (); SKN`2[ahD
} u c)eil
} [|$h*YK
{}przrU^c
//日志 &Z@o Q
public static void log(String sMsg) RbnVL$c
{ N>`Aw^ _@&
System.err.println(sMsg); +Kc
} vh%B[brUJ
nR~@#P\
T?0eVvM
public static void log(int sMsg) BDDlQci38
{ O0v}43J[
System.err.println(sMsg); F/{!tx
} T'9'G M
} Sz`,X0a
RtS+<^2a;
? OM!+O
/* 1CZgb
**TestMethod.java T7%S #0,p
*/ 6d}lw6L
package NetFox; F)QDJE0
]_gU#,8
q3!bky\
public class TestMethod { @S;'@VC
/,yd+wcW#
!e<^? r4
public TestMethod() kDioD
{ ///xx/weblogic60b2_win.exe bAqA1y3=
try{ .L~AL|2_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (w3YvG.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2/^3WY1U
SiteFileFetch fileFetch = new SiteFileFetch(bean); ES7s1O$#
fileFetch.start(); ouQ T
} M6jy\<a
catch(Exception e){e.printStackTrace ();} ~36!?&eA8
g3y~bf
@": ^)87
} tyFzSrfc
8GUX{K
n-;`Cy`k
public static void main(String[] args) k y7Gwc
{ wi=v}R_
new TestMethod(); vk^xT
} n7[V&`e_
} 1Pu~X \sO
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