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)); Xw}Y!;<IEu
} Rp%\`'+Xz
for(int i=0;i<nEndPos.length-1;i++) C4SD
{ as\K(c9
nEndPos = nStartPos[i+1]; HV.|Eh_7
} 52C-D+zCJ
nEndPos[nEndPos.length-1] = nFileLength; ~bWWu`h
} Z$m2rZ#
} JjTzq2'%
DRg~HT
X#NeB>~
//启动子线程 }AH|~3|D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r|H!s,
for(int i=0;i<nStartPos.length;i++) __zu-!v
{ Sy0s`\[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +Tc(z{;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <"|<)BGeI
nStartPos,nEndPos,i); {msB+n~WZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "a`0w9Mm}
fileSplitterFetch.start(); E#X!*q&
} WSB|-Qj}W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M(]|}%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'JKvy(n>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u1|Y;*
nEndPos = " + nFileLength); qD>Y}Z!
// fileSplitterFetch[nPos.length-1].start(); A`U2HC
CbvL X="%
BaHgc 4zI
//等待子线程结束 g:e8i~
//int count = 0; K|J#/
//是否结束while循环 @j8L{FGnN
boolean breakWhile = false; &7kSLat+9{
96V, [-arf
3SB7)8Id1
while(!bStop) }lvP|6Y: y
{ @_(@s*4W
write_nPos(); Ko1?jPE
Utility.sleep(500); T+{'W
breakWhile = true; hB<z]sl
C00*X[p
kC#B7*[RM
for(int i=0;i<nStartPos.length;i++) SD.*G'N&2f
{ %fSk "%u%<
if(!fileSplitterFetch.bDownOver) 9NoPrR=x1
{ eMd1%/[
breakWhile = false; 2iINQK$
break; b({b5z.A
} McI4oD~"
} ['YRY B
if(breakWhile) qmeEUch`
break; ez9M]! 8Lt
fq!6#Usf;i
}sNZQ89V*v
//count++; eDZ3SIZ
//if(count>4) RKZk/ly
// siteStop(); gR6T]v
} c+M@{EbuN
J0)WRn"h
z+B
System.err.println("文件下载结束！"); W p* v Vv
} K<9MK>T
catch(Exception e){e.printStackTrace ();} 0`Qs=R`OM
} xF>w r r
w`Aw+[24
Q-%=ZW Z
//获得文件长度 tZ2iSc
public long getFileSize() 30v1VLR_)
{ 3~09)0"!d
int nFileLength = -1; lxJ.h&"P
try{ CxN@g'
URL url = new URL(siteInfoBean.getSSiteURL()); rpI7W?hh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2Yf;b9-k
httpConnection.setRequestProperty("User-Agent","NetFox"); 2F(\}%UT~
+|w~j#j9`
mZ&Mj.0+~
int responseCode=httpConnection.getResponseCode(); T:n^$RiT
if(responseCode>=400) lMf5F8
{ WD1$"}R
processErrorCode(responseCode); 4Lq]yUj
return -2; //-2 represent access is error -Af`AX
} ] ]-0RJ=S?
'(:J|DN
TZ]Gl4@
String sHeader; ! yUKNR
Z- Ae'ym
P@![P Ij
for(int i=1;;i++) ]h8V{%H
{ *Bz&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g2_df3Q
//Utility.log(in.readLine()); P9!]<so
sHeader=httpConnection.getHeaderFieldKey(i); }Q(I&uz
if(sHeader!=null) 4f~ZY]|nM
{ )_ u'k /
if(sHeader.equals("Content-Length")) VDN]P3
{ ^0~1/ PhOw
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AlhiF\+ C
break; ZDD|MH
} 3"%44'
} xeh|u"5
else PiQs><FK8
break; Nr+1N83S}
} |*a>6y
} 6Ky"4\e
catch(IOException e){e.printStackTrace ();} W5;sps
catch(Exception e){e.printStackTrace ();} fJV VW
u^[v{hv'H
iKKWn*u
Utility.log(nFileLength); / /rWc,c
Om~C0
~PAn _]Z
return nFileLength; A84HaRlkF5
} b=l}|)a
pQ\ [F
VX%\_@
//保存下载信息（文件指针位置） /L Tyiiz6
private void write_nPos() fs12<~+z
{ A1;t60z+q>
try{ oOz6Er[KO
output = new DataOutputStream(new FileOutputStream(tmpFile)); S"z4jpqn3
output.writeInt(nStartPos.length); xKux5u_
for(int i=0;i<nStartPos.length;i++) ".Ug A\0
{ Y{@[)M{<
// output.writeLong(nPos); %syBm
output.writeLong(fileSplitterFetch.nStartPos); K;lC#
output.writeLong(fileSplitterFetch.nEndPos); }y/t~f+
} GTvb^+6
output.close(); ?xs0J
} !*-cf$
catch(IOException e){e.printStackTrace ();} ~h.B\Sc]Q
catch(Exception e){e.printStackTrace ();} R[t[M}q
} ~ $&
V [>5
RwKN
//读取保存的下载信息（文件指针位置） >o7k%T|l$
private void read_nPos() 95&HsgdxJ
{ )9->]U@
try{ &YMj\KmlSg
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uuB\~ #?T
int nCount = input.readInt(); hn.fX:}
nStartPos = new long[nCount]; mqw.v$>
nEndPos = new long[nCount]; ~3 (>_r
for(int i=0;i<nStartPos.length;i++) p(>'4#|qy
{ ^j7pF.j
nStartPos = input.readLong(); {BU,kjv1g
nEndPos = input.readLong(); D bJ(N h
} 35T7g65;
input.close(); 7h~M&\M
} VPbNLi
catch(IOException e){e.printStackTrace ();} Y$^QH.h
catch(Exception e){e.printStackTrace ();} q?\D9aT9
} \266N;JrN
#>'0C6Xn
j!dklQh0
private void processErrorCode(int nErrorCode) \ZH=$c*W
{ 8%Lg)hvl
System.err.println("Error Code : " + nErrorCode); 7Cjrh"al"
} g9JtWgu
fM{Vy])J
qE[}Cf]X
//停止文件下载 jF8ld5|_|
public void siteStop() _De;SB%V
{ hZy*E[i
bStop = true; = '[@UVH(Z
for(int i=0;i<nStartPos.length;i++) 5KzU&!Zh9
fileSplitterFetch.splitterStop(); k,,}N9
3*<W`yed
!;-x]_
} Pmb`05\
} S"l&=J2dc
//负责部分文件的抓取 9Wn0YIc
**FileSplitterFetch.java VM`."un]
*/ ,D1QJPM
package NetFox; |HLh?AcX
C{-pVuhK+
1+'3{m \5T
import java.io.*; +zvK/Fj2q
import java.net.*; *h1@eJHMz
)U` c9*.
|u[gI+TUE
public class FileSplitterFetch extends Thread { rxA<\h,A
P^UcpU,
7w|s8B
String sURL; //File URL nYY U
long nStartPos; //File Snippet Start Position j#,O,\
long nEndPos; //File Snippet End Position tp"\
int nThreadID; //Thread's ID e_SlM=_u
boolean bDownOver = false; //Downing is over Rk<:m+V=
boolean bStop = false; //Stop identical (_2eiE71
FileAccessI fileAccessI = null; //File Access interface l:+1j{ d7
Up:#Zs2
= j -
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "q8wEu,z[
{ [}D)73h`
this.sURL = sURL; eYFCf;
this.nStartPos = nStart; &oBJY'1
this.nEndPos = nEnd; r\zK>GVm_
nThreadID = id; P+xZaf H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 & CgLF]
} ^H'#*b0u
K^+B"
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public void run() _B2t|uQ
{ Wo&i)S<i0F
while(nStartPos < nEndPos && !bStop) %zGPF
{ Rp#SqRy`
=g ]C9'I3
QnqX/vnR
try{ ,=FYf|Z
URL url = new URL(sURL); %2.T1X%!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4dO>L"
httpConnection.setRequestProperty("User-Agent","NetFox"); u4Sa4o
String sProperty = "bytes="+nStartPos+"-"; T!n<ya!
httpConnection.setRequestProperty("RANGE",sProperty); S}<(9@]z
Utility.log(sProperty); Q]\xO/
'EQAG' YV
=vWnqF:
InputStream input = httpConnection.getInputStream(); 2 UgjH
//logResponseHead(httpConnection); Tb[GZ,/%;
${?Px c{-
ZISR]xay
byte[] b = new byte[1024]; tU(6%zvR
int nRead; @U}UCG7+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ny}?+&K
{ wGB'c's*
nStartPos += fileAccessI.write(b,0,nRead); WrV|<%EQh
//if(nThreadID == 1) )S]c'}^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [4gv_g
} Gfvz%%>l
L.5GX 29
c;WS !.
Utility.log("Thread " + nThreadID + " is over!"); ?FLjvmE9
bDownOver = true; =y<Fz*aA
//nPos = fileAccessI.write (b,0,nRead); 8n56rOW!
} m+L:\mvA
catch(Exception e){e.printStackTrace ();} ~=71){4A
} fRbVc
} o,d:{tt
90q*V%cS
[wExjLW
//打印回应的头信息 *Q)+Y&qn
public void logResponseHead(HttpURLConnection con) $u P{,ML
{ + 7Z%N9
for(int i=1;;i++) NIgt"o[I
{ S+He
String header=con.getHeaderFieldKey(i); SXhJz=h
if(header!=null) vK$W)(Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dCinbAQ
Utility.log(header+" : "+con.getHeaderField(header)); cD 1p5U
else $HaM, Oh;i
break; z\\MLyS
} b_B4
} L U7.
v>,XJ7P
G#csN&|,
public void splitterStop() !l}es4~.a
{ Q>|<R[.7
bStop = true; V Bg$r[
} p4/D%*G^`
Ft07>E$/Q^
0g1uM:;
} ]`lTkh
CkOd>Kn
f#!Ljjf$;
/* R8mL|Vb|
**FileAccess.java H6L`239u
*//文件访问(定位，写) {3l]/X3
package NetFox; :/u EPki
import java.io.*; #jnb6v=5v
cc@y
f>Ge Em~
public class FileAccessI implements Serializable{ + 505
G-Y8<mEh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Baq&>]
RandomAccessFile oSavedFile; s01n[jQ
long nPos; 5YRa2#d
AH;h#dT
PJ);d>tz
public FileAccessI() throws IOException V ]Z{0
{ EayZ*e]
this("",0); .(! $j-B
} Ygg+*z
?(E$|A
d5h:py5
public FileAccessI(String sName,long nPos) throws IOException 5Ba eHzI
{ SlmgFk!r!
oSavedFile = new RandomAccessFile(sName,"rw"); Z5v\[i@H!
this.nPos = nPos; SoCa_9*X
oSavedFile.seek(nPos); #HqXC\~n
} 9Y0w SOSW
DRal{?CH
0DGXMO$;
public synchronized int write(byte[] b,int nStart,int nLen) T$SGf.-
{ }LOAT$]XI
int n = -1; ?v6xaVg:
try{ {>90d(j
oSavedFile.write(b,nStart,nLen); 1X]?-+',.
n = nLen; tX)^$3A
} [V =O$X_
catch(IOException e) p?ICZg:
{ &S/KR$^ %
e.printStackTrace (); wD4Kil=v
} kid@*.I
iXI >>9
a:C ly9
return n; G8j$&1`:
} H|5\c=
Gq?JMq#
H}`}qu #~V
} jruwdm^
ZPRkk?M}.
[$$i1%c%Z<
/* r"c<15g2'
**SiteInfoBean.java =5J}CPKbZI
*/ EP,lT.u3
package NetFox; Re-4y5f
"H#2
'V/+v#V+>
public class SiteInfoBean { eX>x +]l6
U8 '}(
`bNY[Gv>)
private String sSiteURL; //Site's URL h<JV6h:8
private String sFilePath; //Saved File's Path C`Zz\DNG@
private String sFileName; //Saved File's Name &Yb!j
private int nSplitter; //Count of Splited Downloading File O(#DaFJv
icH\(
CKCot
public SiteInfoBean() 4"7/+6Z
{//nSplitter的缺省值为5 w6aq/m"'
//default value of nSplitter is 5 G?*)0`~W
this("","","",5); FbhF45H
} <<4U:
yJNQO'wcv
@X5F$=aqZr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @#rF8;
{ g\:(1oY
sSiteURL= sURL; WWZ`RY
sFilePath = sPath; vL}e1V:
sFileName = sName; ^\KZE|^3@
this.nSplitter = nSpiltter; ?NWc3 .
-Q9} gaH_
d0YDNP%,_
} muc6gwBp
lk;4l Z
m7!Mstu
public String getSSiteURL() n3y`='D
{ 6fY-DqF!
return sSiteURL; @Jr:+|v3B
} MfNsor
W"$sN8K>)
+VT/c
public void setSSiteURL(String value) C%H{"
{ )B)ecJJ_
sSiteURL = value; F=EG#<@u
} juIi-*R!
OXp(rJ*bK
hh#p=Y(f
public String getSFilePath() 9X/]O<i,Es
{ Kjzo>fIC{
return sFilePath; PUcxlD/a}
} UB^OMB-W.m
K,j'!VQA4g
O3 NI
public void setSFilePath(String value) 3127 4O
{ ;8m)a
sFilePath = value; "lLwgh;
} H< 51dJn~
W-D{cU
gv\WI4"n
public String getSFileName() ur\<NApT;
{ m55|&Ux|
return sFileName; mSeCXCrZlI
} l]R=I2t
+adwEYRrr
Y<qWG8X
public void setSFileName(String value) 4M*Z1
{ ?*LVn~y
sFileName = value; ~ kwS`
} }iIZA>eF
C2 4"H|D
#K&XY6cTj
public int getNSplitter() )[wB:kG
{ z|bAZKSRYx
return nSplitter; HQ:Y:
} 4g+Dp&U
=aBc.PJ^
:_k5[KT.]9
public void setNSplitter(int nCount) |tN:o= 6
{ 7D&O5Z=%+
nSplitter = nCount; Lo,uH`qU
} }i._&x`):
} >)^Q p-
gx9=L&=d
g286 P_a`*
/* `:.a5
**Utility.java t#d{hEr
*/ *[Im].
package NetFox; rHiBW!
F/ o }5H
?[?;%Y
public class Utility { ?xwLe
o3W@)|>
wU(p_G3
public Utility() O!se-h5mW8
{ nD.K*#u
CT?4A1[aD
= IJ}b=:
} y**YFQ*sc
7bk`u'0%
//线程睡眠 HSR,moI
public static void sleep(int nSecond) \AeM=K6q+D
{ Pj8W]SA_
try{ i&^]qL|J
Thread.sleep(nSecond); AO]k*N,N
} w?V;ItcL
catch(Exception e) Fe1XczB
{ ka/>jV"
e.printStackTrace (); )LAG$Cn
} qh|fq b
} 6t=)1T
m<sCRWa-
//日志 RiG]-K:
public static void log(String sMsg) #+&"m7 s
{ tH=jaFJ
System.err.println(sMsg); ZZ>F ^t
} GC`/\~TM
v,|jmv+:
[}I|tb>Pg
public static void log(int sMsg) 9zl-C*9vj
{ T]x]hQ
System.err.println(sMsg); Q[Gs%/>
} (QTQxZ
} 1}R\L"
M1=eS@
{>UT'fa-
/* 3/y"kl:<-
**TestMethod.java :28[k~.bo
*/ f}EsS
package NetFox; RK/>5
Vkfc&+
OP|X-
public class TestMethod { IdoS6
!5 ?<QKOe
3N?"s1U
public TestMethod() <m/XGFc
{ ///xx/weblogic60b2_win.exe _6m{zvyX>
try{ Dtox/ ,"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xFcW%m>9C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); RdB,;Um9f
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5?A<('2
fileFetch.start(); `(r0+Qx
} yU>ucuF
catch(Exception e){e.printStackTrace ();} +~EnrrT+W
;6$W-W _
uSJLIb
} ^HU>fkSk
CF6qEG6
:Wihb#TO)
public static void main(String[] args) _yp<#q]
{ 1,Jy+1G0w
new TestMethod(); Pv|sPIIB7
} ymn@1BA8J
} Yfx?3
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