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)); uS<_4A;sD,
} NTmi 2c
for(int i=0;i<nEndPos.length-1;i++) K2rzhHfb
{ n ~,tQV
nEndPos = nStartPos[i+1]; 30Drrno7Io
} ;..o7I
nEndPos[nEndPos.length-1] = nFileLength; i]o"_=C
} t-7og;^8k
} s_ bR]G
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/ty?<24ko
//启动子线程 M#,Q ^rH#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }Qr6l/2
for(int i=0;i<nStartPos.length;i++) Br5o7(AE
{ TDNf)Mm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -rSIBc:$8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9V 0}d2d
nStartPos,nEndPos,i); 7G93,dJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B_^]C9C|
fileSplitterFetch.start(); edvFQ#,d
} +dW|^I{H}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u\1>gDI)|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !EBY@ Y1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SJ?)%[(T
nEndPos = " + nFileLength); _yH`t[
// fileSplitterFetch[nPos.length-1].start(); A??@AP[7M
~i~%~doa
r&3pM2Da}
//等待子线程结束 \7v)iG|#G&
//int count = 0; ..W-76{
//是否结束while循环 G64Fx*`
boolean breakWhile = false; f{&bOF v
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OJO!FH)
while(!bStop) ;_?MX/w|&
{ )2e#HBnH
write_nPos(); ,!#ccv+Vm%
Utility.sleep(500); 'UU\4M
breakWhile = true; 0CExY9@Wq
g);^NAA
"3CJUr:Q
for(int i=0;i<nStartPos.length;i++) w#y0atsg'
{ R^#@lI~
if(!fileSplitterFetch.bDownOver) ^jE8+h
{ -yAQ
breakWhile = false; pB:$lS
break; nY%5cJ`"
} f9u^R=Ff[
} BUZ _)
if(breakWhile) =EP13J
break; K2)!h.W
?~e3&ux
)cJ#-M2
//count++; ,:2'YB
//if(count>4) YwEpy(}hJm
// siteStop(); -Z-f1.Dm5
} (N-RIk73/O
A7_4.VH
%r\n%$@_
System.err.println("文件下载结束！"); =T?}Nt
} /1UOT\8U
catch(Exception e){e.printStackTrace ();} ||7x;2e
} d*8 $>GA
<xpph t<
mEG6
//获得文件长度 S[3iA~)Z-
public long getFileSize() `4?~nbz
{ I=)hWC/
int nFileLength = -1; zET^T5>:
try{ ipnV$!z
URL url = new URL(siteInfoBean.getSSiteURL()); #p(h]T32
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3rW|kkn
httpConnection.setRequestProperty("User-Agent","NetFox"); z;f2*F
} p FQRSOZ
>^Q&nkB"B
int responseCode=httpConnection.getResponseCode(); d_UN0YT<
if(responseCode>=400) AN:sQX`
{ !l?.5Pm])
processErrorCode(responseCode); H(c72]@Vg
return -2; //-2 represent access is error }U~6^2 .,
} mYN7kYR}<`
Y`7~Am/r;&
='ZRfb&
String sHeader; h+p*=|j`
EC2+`HJ"
xJ^>pg8
for(int i=1;;i++) S1Z2_V
{ (/!r(#K0,'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +y7;81ND
//Utility.log(in.readLine()); ?_x q-
sHeader=httpConnection.getHeaderFieldKey(i); E1dD7r\
if(sHeader!=null) S:4crI
{ N7'OPTKt&
if(sHeader.equals("Content-Length")) >z;[2n'
{ ~CB[9D=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,g-EW jN
break; d2oh/j6`TA
} K8n4oz#z
} H1<>NWm!v7
else qPB8O1fyU
break; f.aSKQD
} HX'FYt/?t
} D']ZlB'K
catch(IOException e){e.printStackTrace ();} P71(
catch(Exception e){e.printStackTrace ();} T2}FYVj?!g
Zfk*HV#\
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Utility.log(nFileLength); tQZs.1=z
ZX ?yL>4
Vfv@7@q
return nFileLength; f|^dD`
} CTWn2tpW
.s#;s'>g
mNmLyU=d
//保存下载信息（文件指针位置） :[ k4Z]t8
private void write_nPos() O: @}lK+H
{ rl9.]~
try{ Hzrtlet
output = new DataOutputStream(new FileOutputStream(tmpFile)); fLV"T_rk
output.writeInt(nStartPos.length); 1;Pv0&[q/
for(int i=0;i<nStartPos.length;i++) z0|&W&&D
{ : ^ 8
// output.writeLong(nPos); c/B'jPt
output.writeLong(fileSplitterFetch.nStartPos); v9Xp97J2
output.writeLong(fileSplitterFetch.nEndPos); )p!7#v/@f
} jTLSdul+
output.close(); 2o>)7^9|#<
} LL|7rS|o
catch(IOException e){e.printStackTrace ();} f;}EhG'
catch(Exception e){e.printStackTrace ();} Zy|Mz&
} sAgKg=)
Vi4~`;|&b+
?<G]&EK~~]
//读取保存的下载信息（文件指针位置） Ed9Z9
private void read_nPos() K}6dg<
{ "t^URp3
try{ w8g,a]p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]xguBh]
int nCount = input.readInt(); 1? FrJ6V
nStartPos = new long[nCount]; `DT3x{}_S
nEndPos = new long[nCount]; '#(v=|J
for(int i=0;i<nStartPos.length;i++) )sho*;_o
{ zG e'*Qei
nStartPos = input.readLong(); 97K[(KE
nEndPos = input.readLong(); # O4gg
} |+`c3*PV
input.close(); ='TE,et@d
} c)@>zto#
catch(IOException e){e.printStackTrace ();} *>VVt8*Et
catch(Exception e){e.printStackTrace ();} 0flg=U9
} E~LTb) !
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iS5W>1]
private void processErrorCode(int nErrorCode) e@{i
{ 8ssJ<LP
System.err.println("Error Code : " + nErrorCode); Q[+ac*F=Y
} :SxW.?[%u
Fu^^i&
`bc;]@"
//停止文件下载 [frq 'c
public void siteStop() UX]L;kI
{ 0euuT@_$
bStop = true; uUKcB:
for(int i=0;i<nStartPos.length;i++) V5U?F6
fileSplitterFetch.splitterStop(); D~o$GW%
JoSJH35=:
.(Qx{r$
} Tr^nkD{
} pHoEa7:
//负责部分文件的抓取 J<Pw+6B~
**FileSplitterFetch.java z"*/mP2
*/ r!,}Z=cGe
package NetFox; xV%6k{_:G
&CwFdx:Ff
*'"^NSJ
import java.io.*; #M A4
import java.net.*; 4[r/}/iGo
P]z[v)}
U\rh[0
public class FileSplitterFetch extends Thread { #lU9yv
|pa$*/!NT
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String sURL; //File URL fu$R7
long nStartPos; //File Snippet Start Position /t-fjB{=G
long nEndPos; //File Snippet End Position pu,?<@0YK
int nThreadID; //Thread's ID "*O4GPj
boolean bDownOver = false; //Downing is over .UoOO'1K
boolean bStop = false; //Stop identical 2c?qV
FileAccessI fileAccessI = null; //File Access interface ~H6r.:]
;O<9|?
kF>o.uSV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I}2P>)K
{ jjM{]
this.sURL = sURL; ;Eec5w1
this.nStartPos = nStart; q64k7<C,
this.nEndPos = nEnd; >c-fI$]
nThreadID = id; _20#2i&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `>o?CIdp
} y$<Vha
Y wkyq>Rv
N N|u_
public void run() qaim6a
{ G^"Vo x4
while(nStartPos < nEndPos && !bStop) X0*QV- RN
{ -YD+(c`l
hp"L8w
lWm'
try{ >%E([:$A
URL url = new URL(sURL); M/Pme&%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ! Q<>3xZ
httpConnection.setRequestProperty("User-Agent","NetFox"); 5<L_|d)0"
String sProperty = "bytes="+nStartPos+"-"; U:F/iXz
httpConnection.setRequestProperty("RANGE",sProperty); %zU`XVNN+
Utility.log(sProperty); *Ei|fe$sa
|w}xl'>q
m`6Yc:@E
InputStream input = httpConnection.getInputStream(); a(]`F(L
//logResponseHead(httpConnection); 1}ZKc=Pfu
$;G{Pyp
(Toq^+`c
byte[] b = new byte[1024]; `]Bxn)b(
int nRead; >+5?F*`\D*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) . |*f!w}5
{ #}^-C&~
nStartPos += fileAccessI.write(b,0,nRead); ``ekR6[8c
//if(nThreadID == 1) 7kKy\W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sS TPMh
} vILy>QS)
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v&FF|)$
Utility.log("Thread " + nThreadID + " is over!"); ZtVAEIZ)
bDownOver = true; VGL#!4wK
//nPos = fileAccessI.write (b,0,nRead); 9dh>l!2
} hC_Vts[v/
catch(Exception e){e.printStackTrace ();} EliTFxp
} ~](fFa{
} YJxw 'U >P
hl&-\dc+
avp;*G}
//打印回应的头信息 TST4Vy3
public void logResponseHead(HttpURLConnection con) ^BZkHAp
{ TgU**JN)
for(int i=1;;i++) n3MWs);5
{ #sKWd
String header=con.getHeaderFieldKey(i); 1r r@
if(header!=null) t"j|nz{m
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $V6^G*Q
Utility.log(header+" : "+con.getHeaderField(header)); zm9TvoC%}
else W&:[r/8wA
break; 3>z[PPw
} q^rl)
} wxLXh6|6%_
u!N{y,7W)
~`Qko-a&
public void splitterStop() f]~c)P Cs
{ i54md$Q^
bStop = true; vAP{;Q0i
} yj@tV2
F="z]C;u
M ixwK,
} V[pvJ(
u}9fj
,gnQa
/* %>Xr5<$:&
**FileAccess.java r0m)j
*//文件访问(定位，写) z}}]jR\y?
package NetFox; j_?cpm{~ml
import java.io.*; P2n2Qt2
_8K%`6!"Z
;~HNpu$
public class FileAccessI implements Serializable{ gvli%9n
:s8A:mx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 YTY%#"
RandomAccessFile oSavedFile; aj|5 #
long nPos; v@ONo?)
SA6hbcYk
OsW"CF2
public FileAccessI() throws IOException +?-qfp,:0
{ hQh9ok8S
this("",0); L9IGK<
} &B-[oqC?
snk$^
YaFcz$GE_
public FileAccessI(String sName,long nPos) throws IOException bLG]Wa
{ {KaN,td9
oSavedFile = new RandomAccessFile(sName,"rw"); +h[e0J|v{
this.nPos = nPos; 7{BnXN[
oSavedFile.seek(nPos); 3\!F\tqD \
} $"fo^?d/s
y~#\#w{
;R1B9-,
public synchronized int write(byte[] b,int nStart,int nLen) .A<sr
{ P!+v:'P5f
int n = -1; {Qtq7q.
try{ &zN@5m$k;
oSavedFile.write(b,nStart,nLen); hjY0w
n = nLen; 9G:TW|)L[Q
} Gj6. Iv
catch(IOException e) H/i<_LP
{ }z'DWp=uN
e.printStackTrace (); PKtU:Eg
} eOrYa3hQ
IhW7^(p\
Qyj(L[KJ
return n; 5-p.MGso
} &telCg:
_^;;i4VZ
6+%-GgPf
} oeNzHp_
fNxw&ke8&
N$'>XtO
/* i| xt f
**SiteInfoBean.java PRpE$`WK
*/ =x4a~=HX
package NetFox; A[9NP-~
}J;~P 9Y
F"BL#g66
public class SiteInfoBean { 4Iq5+Q
5+FLSk
9r8D*PvS
private String sSiteURL; //Site's URL *aG"+c6|
private String sFilePath; //Saved File's Path Q [:<S/w
private String sFileName; //Saved File's Name _?Ckq
private int nSplitter; //Count of Splited Downloading File ;Vo mFp L
66dTs,C
j)Lo'&Y~=
public SiteInfoBean() CgoXZX
{//nSplitter的缺省值为5 JX&~y.F
//default value of nSplitter is 5 sS'{QIRC'
this("","","",5); fM9xy \.
} lbofF==(
{r{>?)O
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bZXlJa`'S
{ =SL^>HS.fo
sSiteURL= sURL; f\=6I3z
sFilePath = sPath; h/9Sg*k
sFileName = sName; hG~Uz
this.nSplitter = nSpiltter; }JGq1
fr]Hc+7
wNR=?Z~
} Hi7G/2t@`
lR[z<2w\
DZ%8 |PmB
public String getSSiteURL() 'yeh7oR
{ Uk|9@Auav
return sSiteURL; \aB&{`iG
} 1V\1]J/
acy"ct*I
LiF.w:}
public void setSSiteURL(String value) tB!|p6
{ T5V$wmB\W
sSiteURL = value; pdy+h{]3
} %27G2^1
?Cc$]
8W{ g
public String getSFilePath() 8vu2k>
{ 6XZN>#
return sFilePath; + p'\(Z(
} HK?Foo?
?SB5b,
%"{?[!C ?
public void setSFilePath(String value) KM EXT$p
{ zcZ^s v>
sFilePath = value; ]KzJ u`O%G
} n/Or~@pHD
hg!x_Eq|
rC~_:uXtE
public String getSFileName() qP@L(_=g
{ \?[O,A
return sFileName; x={kjym L
} La@\q[U{@
n2H&t>N
vxF:vI# @
public void setSFileName(String value) K T%i,T
{ McO@p=M
sFileName = value; "hJ7 Vv_
} 7ucx6J]c
6_x}.bkIx=
elNB7%Y/
public int getNSplitter() 2J1B$.3'
{ ^V_ku@DY
return nSplitter; Q=dw 6
} [9'|7fdU
%-T}s`Z
/vMQF+
public void setNSplitter(int nCount) xq8}6Q
{ 5+o 2 T]
nSplitter = nCount; nYo&x'
} >cC Gx
} v/QEu^C
"v*oga%
+d|:s
/* 8ct+?-3g
**Utility.java -Y5YCY!`
*/ #i'C
package NetFox; 9[6G8;<D&
q}wl_ku9+
{ILp[&sL
public class Utility { 3RBpbTNWp
^p{A!I!
WV5r$
public Utility() S.zg&
{ Gsx^j?
N` @W%
tg4LE?nv
} fU\k?'x_
we6+2
//线程睡眠 [flu|v
public static void sleep(int nSecond) n23%[#,r
{ yf0vR%,\
try{ ::^qy^n
Thread.sleep(nSecond); iX0]g45o
} lo IL{2
catch(Exception e) ]{q-Y<{"
{ x9FLr}e
e.printStackTrace (); wdN>KS2!
} OX#eLco
} p 02nd.R6
`2 %eDFZ
//日志 j3sz*:
public static void log(String sMsg) wsdB; 6%$
{ e>ZbZy?
System.err.println(sMsg); tkm~KLWV&7
} 3[00-~&U
wI1M0@}PV
d=xI
public static void log(int sMsg) |,M#8NOp:
{ t(uB66(_F
System.err.println(sMsg); +Tgy,oD0
} JN;TGtB^p
} &"~,V6,q
HlOAo:8'
(IO\+
/* MIk #60Ab
**TestMethod.java Sh~ 8jEk
*/ 9}'l=b:Jms
package NetFox; !"o1ve`{
/jK17}j
$h|I7`
public class TestMethod { dcrJ,>i}
kcma/d
RpaA)R,
public TestMethod() MZ|c7f&`
{ ///xx/weblogic60b2_win.exe Z7KB?1{G
try{ {$u@6& B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G}9bCr,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n'x`oI)-
SiteFileFetch fileFetch = new SiteFileFetch(bean); a518N*]j
fileFetch.start(); .Mft+,"
} "62Ysapq+
catch(Exception e){e.printStackTrace ();} p$!+2=)gY
I9j+x])
d\<aJOi+-
} ,DUQto
e!x-:F#4j
Vi-!E
public static void main(String[] args) 2] wf`9ZH
{ )+{omQ7v
new TestMethod(); yLa5tv/
} uB&I56
} _(s|Q
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