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)); 5)X;q-
} aRFLh
for(int i=0;i<nEndPos.length-1;i++) !]]QbB
{ ;M,u,KH)/
nEndPos = nStartPos[i+1]; C? pi8Xg
} VA4>!t)
nEndPos[nEndPos.length-1] = nFileLength; J[E_n;d1
} yh9fHN)F
} {ctEjgiE
/7WN,a
cBICG",TA
//启动子线程 H:9Z.|{Gv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "-aak )7w
for(int i=0;i<nStartPos.length;i++) JNhHQvi\
{ w`Q"mx*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0Y rdu,c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RiHOX&-7
nStartPos,nEndPos,i); 4dy2m!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a^yBtb~,P
fileSplitterFetch.start(); lZT9 SDtS
} Xk#"rM< Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @\-i3EhR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J6x#c`Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (!FUu
nEndPos = " + nFileLength); ftBbO8e
// fileSplitterFetch[nPos.length-1].start(); ]3.Un,F
8`bQ,E+2
|$[WnYP
//等待子线程结束 a[TR_uR
//int count = 0; IT,d(UV_
//是否结束while循环 uK6_HvHuy
boolean breakWhile = false; 3f'dBn5
3$Ecq|4J:
.Q'/e>0
while(!bStop) Wxjv=#3
{ k2>gnk0
write_nPos(); z;Pr] *F
Utility.sleep(500); Uh.XL=wY
breakWhile = true; +<p?i]3CHe
M%=V vE.I
oK3uGPi
for(int i=0;i<nStartPos.length;i++) C)^FRnb
{ :uM2cc^
if(!fileSplitterFetch.bDownOver) >dH5n$Gb
{ {"<6'2T3
breakWhile = false; ml7nt0{
break; yX:A?U
} 9G8n'jWyY
} _4E . P
if(breakWhile) W}+f}/&l
break; =GO/r;4
)c9]}:W&
k<b`v&G
//count++; u15-|i{y7
//if(count>4) F8*e
// siteStop(); Eyw)f>
} HVb9YU+
i!zh9,i>M
L||_Jsu
System.err.println("文件下载结束！"); ZLA&<]Ad"$
} 6;/>asf
catch(Exception e){e.printStackTrace ();} c*nH=
} + -e8MvP
tPO\e]
1$,t:/'-4
//获得文件长度 gI^);JrTE
public long getFileSize() r,p6J7/lfS
{ nquKeH
int nFileLength = -1; 1VW;[ ocQ
try{ AF{k^^|H
URL url = new URL(siteInfoBean.getSSiteURL()); >`rK=?12<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }qUNXE@
httpConnection.setRequestProperty("User-Agent","NetFox"); S312h'K j
:SxOQ(n
a/@<KnT
int responseCode=httpConnection.getResponseCode(); u7|{~D&f
if(responseCode>=400) e2#"o{+@
{ 75Xi%mlE7
processErrorCode(responseCode); XQEGMaZ
return -2; //-2 represent access is error |xI\)VE^
} t3 AZS0
bH7[6#y$
GD1=Fb"&)
String sHeader; K GlO;Q~7
T!6H5>zA
1j*I`xZ
for(int i=1;;i++) L2ePWctq}
{ !Ju?REH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yHW=,V.
//Utility.log(in.readLine()); I\R5Cb<p
sHeader=httpConnection.getHeaderFieldKey(i); &s!"pEZWck
if(sHeader!=null) G9\Bi-'ul
{ t+0&B"
if(sHeader.equals("Content-Length")) f~Dl;f~H_;
{ cvn4Q-^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xG<H${ k;
break; :"ZH
} 4!lbwqo
} OwIW;8Z
else +Q, 0kv
break; 7 q<UJIf
} x&3!z[m@@
} ]ABpOrg
catch(IOException e){e.printStackTrace ();} ]Jj\**
catch(Exception e){e.printStackTrace ();} 9H*$3
~CRr)(M
%hU8ycI*h
Utility.log(nFileLength); jY-i`rJN
W38My j!
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return nFileLength; w<_.T#
} Du>dTi~
yWIM,2x}
P,RCbPC4
//保存下载信息（文件指针位置） oS)0,p
private void write_nPos() zypZ3g{vz
{ ).eT~e Gj
try{ sm}q&m]ad
output = new DataOutputStream(new FileOutputStream(tmpFile)); /U<-N'|
output.writeInt(nStartPos.length); uF>I0J#z?
for(int i=0;i<nStartPos.length;i++) ]I"oS?
{ GCrh4rxgg
// output.writeLong(nPos); ^DHFP-G?e
output.writeLong(fileSplitterFetch.nStartPos); L>{E8qv>w
output.writeLong(fileSplitterFetch.nEndPos); p}.P^`~j
} TyMRm
output.close(); 8?W!U*0aS
} ]}9cOb%I
catch(IOException e){e.printStackTrace ();} );$Uf!v4
catch(Exception e){e.printStackTrace ();} ~BCSm]j
} ~\hA-l36
k%QhF]
t~p9iGX<
//读取保存的下载信息（文件指针位置） [(tgoh/
private void read_nPos() AO;`k]0e
{ +-,Q>`
try{ 9>psQ0IRvr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MoA2Cp;8X
int nCount = input.readInt(); >q <,FY!A
nStartPos = new long[nCount]; NTiJEzW}
nEndPos = new long[nCount]; `Oys&]vb
for(int i=0;i<nStartPos.length;i++) zsI0Q47\
{ :c,\8n
nStartPos = input.readLong(); Z~g~,q
nEndPos = input.readLong(); =HP_IG_
} HKP\`KBCj
input.close(); pRXA!QfO
} j._9;HifZ
catch(IOException e){e.printStackTrace ();} fl~k')s
catch(Exception e){e.printStackTrace ();} n4)G g~PE
} #e&j]Q$Eh
N`y!Km
,KkENp_
private void processErrorCode(int nErrorCode) |LKhT4rE
{ }.gDaxj
System.err.println("Error Code : " + nErrorCode); uf`o\wqU
} ~/[cZY@
OM]p"Jd
q=bJ9iJsq
//停止文件下载 qsFA~{o.
public void siteStop() oypq3V=5
{ MLmc]nL=
bStop = true; .eXIbd<C
for(int i=0;i<nStartPos.length;i++) 'O]_A57
fileSplitterFetch.splitterStop(); /{7x|ay]
m&,d8Gss^
jL8&
} BmUEo$w
} i[d-n/)
//负责部分文件的抓取 ci5ERv`
**FileSplitterFetch.java 2DTH|Yv
*/ yt C{,g>
package NetFox; dz5bW>
A3&8@/6,
-+|0LXo
import java.io.*; M6AQ8~z
import java.net.*; P>L-,R(7e
7r"!&P*,
/lttJJDU
public class FileSplitterFetch extends Thread { 8c+i+gp!
~n]:f7?I
8[f]9P/i
String sURL; //File URL @Qruc\_
long nStartPos; //File Snippet Start Position ;#/b=j\pi
long nEndPos; //File Snippet End Position w[PW-m^`
int nThreadID; //Thread's ID {FQ dDIj#
boolean bDownOver = false; //Downing is over oX3Q9)
boolean bStop = false; //Stop identical |\?-k
FileAccessI fileAccessI = null; //File Access interface g_>)Q
* _C6.%{
lqqY5l6j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ReKnvF~
{ D8`,PXtV
this.sURL = sURL; '4HwS$mW3
this.nStartPos = nStart; E3,Z(dpX!
this.nEndPos = nEnd; w \0=L=J
nThreadID = id; (U!WD`Ym
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8 gOK?>'9
} ?xK9
@Z@yI2#e
!SiZA"
public void run() <6p{eGAQV
{ rVQ:7\=Z
while(nStartPos < nEndPos && !bStop) JEY%(UR8
{ `mw@"
W@"M/<r@/
7_#v_ A^
try{ 1P8$z:|~
URL url = new URL(sURL); 6xnJyEQUM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M P0ww$(
httpConnection.setRequestProperty("User-Agent","NetFox"); 76=uk!#3{
String sProperty = "bytes="+nStartPos+"-"; ixiRFBUcF~
httpConnection.setRequestProperty("RANGE",sProperty); R(pvUm&L
Utility.log(sProperty); |[!xLqG
x"AYt:ewuc
v.r$]O
InputStream input = httpConnection.getInputStream(); b)@D*plS&
//logResponseHead(httpConnection); #:' P3)&
^_5$+
-Rjn<bTIy
byte[] b = new byte[1024]; J>hl&J
int nRead; seAkOIc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (jY.S|%
{ + 6r@HK`,t
nStartPos += fileAccessI.write(b,0,nRead); n{4&('NRFP
//if(nThreadID == 1) P[XE5puC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;1{S"UY
} N@Slc 0
2Y 6/,W
a^Zn }R r
Utility.log("Thread " + nThreadID + " is over!"); k qwS/s
bDownOver = true; Ta/G
//nPos = fileAccessI.write (b,0,nRead); ( Y/ DMQ
} ,iSs2&$m
catch(Exception e){e.printStackTrace ();} 'kW`62AX
} 7 hnTHL
} j nI)n*
C6'[Tn
0C3Yina9 *
//打印回应的头信息 Zpu>T2Tp
public void logResponseHead(HttpURLConnection con) ml?+JbLg0
{ V7rcnk#
for(int i=1;;i++) @gxO%@@
{ V3@^bc!
String header=con.getHeaderFieldKey(i); i>)Whr'e8
if(header!=null) D\*raQ`n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c$uV8_V
Utility.log(header+" : "+con.getHeaderField(header)); / d6mlQS
else 8(Z*Vz uu
break; zac>tXU;
} i9.52
} db#y]>^l
9QY)<K~a
4,$x~m`N
public void splitterStop() C?hw$^w7T
{ 6"_FjS3Sl
bStop = true; vj{h*~
} Ap}:^k5{
p[Q
1q\U (^
} m?<C\&)6x
|dX#4Mq^,
FpW{=4yk
/* >xP $A{
**FileAccess.java Y;#P"-yH
*//文件访问(定位，写) ^{~y+1lt'
package NetFox; A|y&\~<A
import java.io.*; TC R(
H.i_,ZF
]4z?sk@
public class FileAccessI implements Serializable{ b;x^>(It
bd)A6a\h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 sBRw#xyS
RandomAccessFile oSavedFile; ,HMB`vF
long nPos; ^vG*8,^S=8
8swj'SjX
2^UFP+Yw
public FileAccessI() throws IOException /6 P()Upe
{ w,`x(!&
this("",0); PkG+`N
} S4?ssI
rm"bplLZA
w #1l)+
public FileAccessI(String sName,long nPos) throws IOException AeUwih. 4
{ FirmzB Il5
oSavedFile = new RandomAccessFile(sName,"rw"); AE7>jkHB
this.nPos = nPos; 2!" N9Adt
oSavedFile.seek(nPos); >mt<`s
} AV&W&$
KtV_DjH:
]Ff&zBJ
public synchronized int write(byte[] b,int nStart,int nLen) ^'FY!^dE
{ t~@TUTbx
int n = -1; .`,YUr$.
try{ 0Y!Bb2m
oSavedFile.write(b,nStart,nLen); 0kC!v,
n = nLen; YtIJJH
} <cepRjDn
catch(IOException e) urog.Q
{ }"xC1<]
e.printStackTrace (); !T @|9PCp
} :5CwRg
M>T#MDK\(
Gm>8= =c
return n; %W`pTvF
} x%x[5.CT
,"}'NH@
gL}K84T$S
} Q) FL|
g7d)YUc
$>#PhOC
/* /- kMzL
**SiteInfoBean.java X8*q[@$
*/ y'E)iI*
package NetFox; !-2S(8
k92189B9j/
# <&=ZLN
public class SiteInfoBean { \=83#*KK
-JUv'fk
0]NsT0M
private String sSiteURL; //Site's URL UGR5ILf
private String sFilePath; //Saved File's Path b/S4b
private String sFileName; //Saved File's Name ^M?uv{354
private int nSplitter; //Count of Splited Downloading File KN+*_L-
TXy*-<#vR
5(DCq(\P*
public SiteInfoBean() R8HA X
{//nSplitter的缺省值为5 *(r85lEou)
//default value of nSplitter is 5 |4-Ey! P
this("","","",5); ]>`Q"g~0
} >:wk.<Z-
9`c :sop
^. Pn)J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m'429E]\S
{ k,q` ^E8k
sSiteURL= sURL; O gycP4z[
sFilePath = sPath; ~8|$KD4I
sFileName = sName; NU_VUd2
this.nSplitter = nSpiltter; Q$RP2&
h!)(R<
8qBw;A)
} _;0:wXib=
, :kCt=4%
[& hdyLt
public String getSSiteURL() Gzm[4|nO^
{ v_G4:tY
return sSiteURL; gw5CU)r4$
} I#9K/[
=#>P!
qLPI^g,
public void setSSiteURL(String value) } 10Dvt>+
{ ,cbP yg
sSiteURL = value; 2poU\|H
} + ^~n09
iAXx`>}m
A 7TP1
public String getSFilePath() 3HfT9
{ -98bX]8
return sFilePath; ;N4mR6
} wV(_=LF
n}._Nb 5
(r7~ccy4
public void setSFilePath(String value) V#sANi?mpo
{ +/UInAM
sFilePath = value; Ya,>E@oc
} \W$>EH
%7L'2/Y2x
~}TVM%0RTq
public String getSFileName() 57r\s8
{ ?DpMR/
return sFileName; +LX&1GX
} ok[R`99
4#=^YuKaF1
c{&sf y
public void setSFileName(String value) [c3hwogf:
{ SUvHLOA
sFileName = value; ^TB%| yZ _
} 4$y|z{[< 5
4\-kzGgmo
`%rqQnVB
public int getNSplitter() a:P% r
{ c.d*DM}W
return nSplitter; \WZ00Y,*
} p%,JWZ[
HK ;C*;vC%
>r{,$)H0
public void setNSplitter(int nCount) $R"~BZbt;
{ )|2g#hH5
nSplitter = nCount; 7$b78wax
} $r_z""eOc
} `cVG_=2
|@Z QoH
H,zRmK6A%
/* Bv/v4(G5g
**Utility.java znu?x|mV
*/ mEE/Olh W
package NetFox; y+X%qTB
AMtFOXx%I
33 N5>}
public class Utility { TNiFl hq
F1MPo;e
,!Ah+x
public Utility() ?K}/b[[0v
{ f$/Daq <M
<v0 d8
:a`l_RMU
} YMm Fpy
=FdS'<GM
//线程睡眠 S* <:He&1
public static void sleep(int nSecond) oBIKtS*L
{ ~9x$tb x-
try{ 6h;$^3x$
Thread.sleep(nSecond); UG1^G07s
} u*PN1E
catch(Exception e) 2uqdx'^"
{ H%sbf& gi
e.printStackTrace (); &o)j@5Y?
} g3"`b)M
} |-Y,:sY:
9g "?`_
//日志 9n44 *sZ
public static void log(String sMsg) `_z8DA}E
{ Riu0;U( \
System.err.println(sMsg); GndF!#?N(
} o3%Gc/6%
&{l?j>|TM
(}c}=V
public static void log(int sMsg) `ZNzDr
{ M-0BQs`N
System.err.println(sMsg); v')T^b F@
} ~ dmyS?Or
} o- GHAQ
.}]5y4UQ.
iv3NmkP1
/* p6I@o7f
**TestMethod.java [ tmJ6^s
*/ Jfo#IRC
package NetFox; *`mwm:4
R%54!f0 %
Hz+edMUL
public class TestMethod { u9}=g%TV
+dIg&}Tr
lts{<AU~
public TestMethod() J Wof<D,
{ ///xx/weblogic60b2_win.exe >5)$Qtz#
try{ aq[kKS`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8CwgV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \>M3E
SiteFileFetch fileFetch = new SiteFileFetch(bean); -pyTzC$HO
fileFetch.start(); ~?S/0]?c
} i!sKL%z}
catch(Exception e){e.printStackTrace ();} W aks*^|
:'a |cjq
>L5[dkg%
} lHr?sMt
/ey}#SHm,
8 w^i
public static void main(String[] args) o{nBtxZ"
{ aElEV e3
new TestMethod(); iv:[]o
} B-'Xk{
} (t fADaJM
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