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)); rtk1 8U-
} 4d )Q
for(int i=0;i<nEndPos.length-1;i++) Kv#TJn
{ T`r\yl}
nEndPos = nStartPos[i+1]; gpe-)hD@R
} zK ir
nEndPos[nEndPos.length-1] = nFileLength; )!C|DSw
} )jaNFJ 3
} "(^1Dm$(
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M{M?#Q
//启动子线程 ] KR\<MJK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =ms o1
for(int i=0;i<nStartPos.length;i++) YLe$Vv735
{ 6)Dp2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #>(h!lT_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m~l[Y
nStartPos,nEndPos,i); sp&)1?!M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); * 57y.](w
fileSplitterFetch.start(); 4I<U5@a
} pk:2>sx/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qC$h~Epp4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9lCZi?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mp+lN:
nEndPos = " + nFileLength); SBqx_4}
// fileSplitterFetch[nPos.length-1].start(); T0Zv.
]Qb85;0)
Tq=OYJq5U
//等待子线程结束 .~fAcc{Qj
//int count = 0; VS_xC$X!S
//是否结束while循环 w`F4.e
boolean breakWhile = false; $ h<l
x1nqhSaD
c=A)_ZFg
while(!bStop) LG3:V'|
{ %$.]g
write_nPos(); {Tym#
Utility.sleep(500); }Qo:;&"3
breakWhile = true; Dt p\T|)
iPoDesp
(>gAnebN L
for(int i=0;i<nStartPos.length;i++) PgF7ug%,@C
{ 3~Vo]wv
if(!fileSplitterFetch.bDownOver) 8I*WVa$l
{ l~9P4 ,
breakWhile = false; VvTs87
break; .}zpvr8YP
} M,nLPHgK
} e.:SBXZ
if(breakWhile) <xWBS/K
break; @fwk
!O~5<tA[#1
|6}:n,KA.
//count++; Sx%vJYH0
//if(count>4) `:fc*n,*
// siteStop(); :6Oh?y@
} "O,TL*$
Q\4nduQ
"mm|0PUJ
System.err.println("文件下载结束！"); 56R)631]p
} -8r9DS-/W
catch(Exception e){e.printStackTrace ();} ]rP'\a
} eTp}*'$p
dJ0qg_ U&
MVpk/S%W
//获得文件长度 y8.(filNB
public long getFileSize() ,awp)@VG7
{ CH/*MA
int nFileLength = -1; NFQR
try{ "Lp"o
URL url = new URL(siteInfoBean.getSSiteURL()); =Nj58l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8+7=yN(
httpConnection.setRequestProperty("User-Agent","NetFox"); fm%1vM$[J
Cyw cJ
VD*xhuy$k
int responseCode=httpConnection.getResponseCode(); ?NL>xMA
if(responseCode>=400) w/(hEF '
{ ]8i2'x
processErrorCode(responseCode); j4B|ktf
return -2; //-2 represent access is error ^YLpZoo
} =_/,C
? <.U,
_+\hDV>v
String sHeader; 5Se S^kJC
iVKX *kqc
~!w()v n
for(int i=1;;i++) &E>zvRBQ
{ 8I'Am"bc\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J0hY~B~X
//Utility.log(in.readLine()); Q*+_%n1 /
sHeader=httpConnection.getHeaderFieldKey(i); 8VwByk8
if(sHeader!=null) .RNr^*AQ
{ *&vySyt
if(sHeader.equals("Content-Length")) ul',!js?
{ 1JU1XQi
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u,6 'yB'u
break; /{~cUB,Um
} S}rW=hO
} -Oro$=%
else ;S FmbZ%~
break; 2_4m}T3
} y ~ A]
} Z-!W#
catch(IOException e){e.printStackTrace ();} W1UG\d`2
catch(Exception e){e.printStackTrace ();} \gE3wmSJ,
y!9facg
T F!Lp:
Utility.log(nFileLength); `2Buf8|a,
m*h, <,}-+
q?=eD^]
return nFileLength; K_Jo^BZ
} AID}NQQj_
Xjal6e)[
3eV(2
//保存下载信息（文件指针位置） K%: :
private void write_nPos() `3$S^|v
{ wNuS'P_(:T
try{ oy-Qy
output = new DataOutputStream(new FileOutputStream(tmpFile)); a/.O,&3
output.writeInt(nStartPos.length); eTc0u;{V
for(int i=0;i<nStartPos.length;i++) )p MZ5|+X
{ T~k5` ~\(
// output.writeLong(nPos); NC;4
output.writeLong(fileSplitterFetch.nStartPos); P^%.7C
output.writeLong(fileSplitterFetch.nEndPos); -4p^wNR
} 1u\fLAXn
output.close(); |4i,Vkfhe
} $V"~\h8
catch(IOException e){e.printStackTrace ();} _"ysJ&
catch(Exception e){e.printStackTrace ();} \jdpL1
} :B=p%C
'\:?FQ C
/hue]ZaQq
//读取保存的下载信息（文件指针位置） *R*Tmo"
private void read_nPos() Ah_'.r1<P9
{ Cm;WQuv@
try{ 8KpG0DC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z,nRw/o
int nCount = input.readInt(); ~>@Dn40
nStartPos = new long[nCount]; .Lrdw3(
nEndPos = new long[nCount]; V*U7-{ *a
for(int i=0;i<nStartPos.length;i++) $cev,OW6]
{ 9-+6Ed^2
nStartPos = input.readLong(); x C'>W"pY
nEndPos = input.readLong(); DVYY1!j<
} ]?L?q2>&
input.close(); a$I; L
} $S$%avRX
catch(IOException e){e.printStackTrace ();} Aa&3x~3+
catch(Exception e){e.printStackTrace ();} 5Mb1==/R
} c@{,&,vsj
bQk5R._got
r4O*0Q_
private void processErrorCode(int nErrorCode) {y|y68y0+
{ S ~lw5
System.err.println("Error Code : " + nErrorCode); uU`zbh}]L.
} (tEW#l'}
S8" h9|
EX8:B.z`57
//停止文件下载 J#CF SG
public void siteStop() wX7B&w8wV
{ au8bEw&W
bStop = true; .1MXQLy
for(int i=0;i<nStartPos.length;i++) |pr~Ohz
fileSplitterFetch.splitterStop(); 0[0</"K%1m
^HKxaW9W
`3r*Ae
} 8oY0?|_Bx
} 4qjY,QJ
//负责部分文件的抓取 G%anot
**FileSplitterFetch.java Y3[<
*/ WJ\YKXG
package NetFox; 8k+Ctk
*#EyfMz-B
!.iA^D//]
import java.io.*; *Yov>lO
import java.net.*; >k^=+
)zt*am;
52*zX 3
public class FileSplitterFetch extends Thread { ^zqz$G#
<?Fgm1=o
v}-'L#6
String sURL; //File URL z@&_3 Gl
long nStartPos; //File Snippet Start Position R\yw9!ESd
long nEndPos; //File Snippet End Position ms3Ec`i9
int nThreadID; //Thread's ID vVKiE 6^
boolean bDownOver = false; //Downing is over 1O9V Ej5
boolean bStop = false; //Stop identical e)\s0#
FileAccessI fileAccessI = null; //File Access interface +(r8SnRX
jKQnox+=
T:wd3^.CG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eUqsvF}l!
{ LP_!g
this.sURL = sURL; RXgi>Hz
this.nStartPos = nStart; Q=~e|
this.nEndPos = nEnd; Oa7`Y`6
nThreadID = id; oHu0] XA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w0moC9#$?
} Z/hSH 0(~
R^dAwt`.D
2hf]XV\
public void run() 2c!?!:s
{ W32mAz;
while(nStartPos < nEndPos && !bStop) Ik=KEOz
{ I2|iqbX40Q
~oT0h[<
"S#0QH%5
try{ ^#exsXy
URL url = new URL(sURL); sKjg)3Sl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,_YCl09p(
httpConnection.setRequestProperty("User-Agent","NetFox"); LUKdu&M
String sProperty = "bytes="+nStartPos+"-"; UX2`x9
httpConnection.setRequestProperty("RANGE",sProperty); sh}=#eb
Utility.log(sProperty); kYxn5+~
Vjj30f
62%.ddM4
InputStream input = httpConnection.getInputStream(); 6E@r9U
//logResponseHead(httpConnection); sqac>v
l[Ng8[R
3j<] W
byte[] b = new byte[1024]; &{y-}[~
int nRead; )#Y*]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Uh?SDay
{ T -C2V$1
nStartPos += fileAccessI.write(b,0,nRead); T\8|Q@
//if(nThreadID == 1) 5x4JDaG2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E+>Qpy
} z{``v|K
6!Ji-'\"
;2)@NH
Utility.log("Thread " + nThreadID + " is over!"); K-k;`s#
bDownOver = true; v?!x,H$Qd
//nPos = fileAccessI.write (b,0,nRead); 69r<Z
} ![U|2x
catch(Exception e){e.printStackTrace ();} bPOehvK/
} -`iZBC50
} 5ah]E
o*I=6`j
2HkP$;lED
//打印回应的头信息 e}kEh+4
public void logResponseHead(HttpURLConnection con) cl1h;w9s
{ M*8Ef^-U`t
for(int i=1;;i++) /S\P=lcb
{ 1/6G&RB
String header=con.getHeaderFieldKey(i); Bz9!a k~4
if(header!=null) 8_8R$=V
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?J6J#{LRd
Utility.log(header+" : "+con.getHeaderField(header)); Z!~~6Sq
else CdatN$/*
break; &'c1"%*%8>
} >UZfi u
} /V2^/`&;a
z~L(kf4
VCNg`6!x
public void splitterStop() L!c7$M5xJ
{ b!5W!vcK
bStop = true; 5Ee%!Pk
} \@GA;~x.b
:=T+sT~
&JtK<g
} -+#\WB{AI
<8+.v6DCd
C:0Ra^i ?L
/* DE^{8YX,
**FileAccess.java K.",=\53
*//文件访问(定位，写) M7fw/i
package NetFox; *s S7^OZ*
import java.io.*; %W+*)u72(
; R&wr_%
o.keM4OQ
public class FileAccessI implements Serializable{ UOy`N~\gh+
O9dIobu4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2u*o/L+
RandomAccessFile oSavedFile; NK~j>>^;v
long nPos; 3!,XR\`[
}R;.~F
3/@7$nV
public FileAccessI() throws IOException bQrH8)
{ ]j~V01p/e
this("",0); 5|9,S
} SLD%8:Zn
]xCJ3.9
-s,^_p{H
public FileAccessI(String sName,long nPos) throws IOException !G90oW
{ `QnKal)
oSavedFile = new RandomAccessFile(sName,"rw"); )d2<;c
this.nPos = nPos; k*w]a
oSavedFile.seek(nPos); >hJ$~4?
} |K,9EM3
&Op, ?\
vjhd|
public synchronized int write(byte[] b,int nStart,int nLen) bT|a]b:
{ /![S 3Ol
int n = -1; *rXESw]BR
try{ R/Mwq#xUb
oSavedFile.write(b,nStart,nLen); ?nn`ud?f
n = nLen; o6'I%Gs
} h*Rh:yCR>
catch(IOException e) 7*r Q6rAP
{ 3qXOsa7
e.printStackTrace (); <_dyUiT$J
} `kpX}cKK}
X2}\i5{
hJ (Q^Z
return n; 1j`-lD
} M$B9?N6
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+\fr3@Yc
} E5~HH($b
t>)iC)^u
C\ZL*,%}
/* Vl%AN;o
**SiteInfoBean.java m.iCGX
*/ rr>QG<i;G
package NetFox; o8-BTq8
{KxeH7S
w4Qqo(
public class SiteInfoBean { j&6,%s-M`a
mSp-
*`mPPts}
private String sSiteURL; //Site's URL zH0%; o}
private String sFilePath; //Saved File's Path yM}}mypS
private String sFileName; //Saved File's Name $3[IlQ?
private int nSplitter; //Count of Splited Downloading File WS/^WxRY
*p`0dvXG2
/`Yy(?,
public SiteInfoBean() 5Q#;4
{//nSplitter的缺省值为5 w},' 1
//default value of nSplitter is 5 DJ_,1F
this("","","",5); #=V%S 2~
} I= G%r/3
ZR.1SA0x?O
ng0IRJ:3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w,bILv)
{ /;-KWu+5=
sSiteURL= sURL; |NJe4lw+?
sFilePath = sPath; L(\sO=t
sFileName = sName; &tB|l_p_-p
this.nSplitter = nSpiltter; 4EQ7OGU
MqGF~h|+
|5_bFB+&
} bZHuEh2w
;2Db/"`t
bW(+Aw=O
public String getSSiteURL() ,d(F|5M:
{ 8/,m8UOY
return sSiteURL; uSLO"\zysX
} }`8g0DPuD9
h!5^d!2,
~=h]r/b< U
public void setSSiteURL(String value) %jdV8D#Q
{ >ygyPl ;1s
sSiteURL = value; r(h&=&T6
} BIEc4k5(
J~eY,n.6]
M[}EVt~
public String getSFilePath() q>/# P5V
{ 8Y*SZTzV
return sFilePath; Fh9%5-t:J
} SlB,?R2
qR4('
^h{AAS>
public void setSFilePath(String value) d"<Q}Ay
{ ^.5L\
sFilePath = value; DQ :w9
} )f-ux5
0#lw?sv
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public String getSFileName() mr6/d1af_
{ F`SOF O
return sFileName; 5 WSu
} /ZqBO*]
zWoPa,
3v)v92;
public void setSFileName(String value) +(0Fab8g
{ 9r-]@6;
sFileName = value; S8*VjG?T\
} E/|]xKG
sP$bp Z}
W.iL!x.B@
public int getNSplitter() R#i|n<x
{ 0@d)DLM?
return nSplitter; xx0s`5
} [hTGWT3
Vo}3E]
|};]^5s9
public void setNSplitter(int nCount) @P#uH5U
{ %ANo^~8
nSplitter = nCount; .yE!,^j.gB
} AN7WMX
} OLJb8kO
$C0NvJf
sUN>uroi !
/* >8Wvz.Nq/
**Utility.java JYL/p9K[I
*/ n)uvN
package NetFox; I'2:>44>I6
=A={Dpv[>
C`+g:qT
public class Utility { XIh2Y\33ys
vn|u&}h
OLUQjvnU
public Utility() ,oX48Wg_+
{ 4b=hFwr[?
CZRrb84
=Xh^@OR
} kF.!U/C
G,M &z>ub0
//线程睡眠 TWYz\Hmw
public static void sleep(int nSecond) QLH&WF
{ :'?%%P
try{ h^^zR)EVb
Thread.sleep(nSecond); 4[a?..X
} e`k6YO
catch(Exception e) fL.;-
{ =MDir$1Z
e.printStackTrace (); ]UKKy2r.
} jT"P$0sJAd
} WXu:mv,'e
eT1b88_
//日志 `}.K@17
public static void log(String sMsg) h=SQ]nV{
{ }[}u5T`w>
System.err.println(sMsg); 0cZyO$.
} dl;~-'0
p 2xOjS1
Cj%SW <v|
public static void log(int sMsg) #P*%FgROl
{ @;kw6f:{d
System.err.println(sMsg); pg~vteq5
} ?g%5 d
} E]w1!Ah M
'Wjuv9)/
Q:eIq<erY
/* v1<gNb)`
**TestMethod.java `bu3S}m7
*/ Af1izS3
package NetFox; Cnd70tbD )
$'e;ScH
rB;`&)-
public class TestMethod { eO;i1>
vF"<r,pg
gP8Fe =]
public TestMethod() 0fA42*s;
{ ///xx/weblogic60b2_win.exe ~E-YXl9
try{ ,!t1( H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B04%4N.g"X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4"1OtBU3
SiteFileFetch fileFetch = new SiteFileFetch(bean); D}'g4Ag
fileFetch.start(); mj5$ 2J
} Ol H{!
catch(Exception e){e.printStackTrace ();} c+?L?s`"
},'hhj]O
6cz%>@
} =2uE\6Fl,
(q`Jef
5r"BavA
public static void main(String[] args) u\=gps/Z
{ !t "uNlN
new TestMethod(); 11}sRu/
} %AW5\ EX
} K:yS24\%
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