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)); $e;_N4d^
} OgNt"Vg
for(int i=0;i<nEndPos.length-1;i++) yFT)R hN
{ *sqq]uD
nEndPos = nStartPos[i+1]; 63d' fgVp
} Eg?6$[U`8<
nEndPos[nEndPos.length-1] = nFileLength; GQTMQXn(
} qJj;3{X2
} 8VJUaL@
dlC)&Ai
N9D<wAK##)
//启动子线程 f~u]fpkz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b]s*z<|%
for(int i=0;i<nStartPos.length;i++) #5kQn>R
{ cbl2D5s+i]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "SyAOOZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =uZ[
nStartPos,nEndPos,i); adh=Kp e!w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d_&R>GmR$
fileSplitterFetch.start(); |~bl%g8xP
} 0(;d<u)fS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [Z484dS`_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0l6z!@GhT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?k~(E`ZE3
nEndPos = " + nFileLength); 0hXI1@8]`
// fileSplitterFetch[nPos.length-1].start(); uYlC*z{
rLNo7i
udDhJ?
//等待子线程结束 V+X>t7.Q
//int count = 0; |b{XnD_g
//是否结束while循环 z!5^UD8"W
boolean breakWhile = false; }\`MXh's
^ad p<?q4
a3 <D1"
while(!bStop) W6D|Rr.q
{ ja}_u}:
write_nPos(); 6)m}e?D>
Utility.sleep(500); Ns2M8
breakWhile = true; !CROc}
3hr&p{/
-:`$8/A|
for(int i=0;i<nStartPos.length;i++) ~AxA ,
{ "W;GvI
if(!fileSplitterFetch.bDownOver) u-3A6Q
{ Fd-PjW/E8
breakWhile = false; - *!R
break; j`A%(()d
} ppjd.
} @ 9D, f
if(breakWhile) bR6.Xdt.n
break; 1HG~}E
YYHtd,0\+
40N8?kQ}?
//count++; D\]gIXg
//if(count>4) `3^*K/K\
// siteStop(); *SQ hXTn
} Iodk1Y;
"qUUH4mR`
6+(g4MW
System.err.println("文件下载结束！"); 6wx;grt'Z
} :}0y[qc3
catch(Exception e){e.printStackTrace ();} F6R+E;"4R'
} 4bqi&h3
XeDiiI
BRbx.
//获得文件长度 EV| 6._Z(D
public long getFileSize() _eM\ /(v[
{ ^AtAfVJN0
int nFileLength = -1; u HqPb8
try{ = ;#?CAa:
URL url = new URL(siteInfoBean.getSSiteURL()); m!5P5U x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &U ]L@]x
httpConnection.setRequestProperty("User-Agent","NetFox"); PXG)?`^NX
nIJ2*QJ
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int responseCode=httpConnection.getResponseCode(); v{ Md4p
if(responseCode>=400) bmVksi2b
{ ]#;;)K}>
processErrorCode(responseCode); T;qP"KWZ
return -2; //-2 represent access is error m07= _4
} x zu)``?
|uId:^{
p9Zi}!
String sHeader; Ac}+Uq
1@sy:{ d`
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for(int i=1;;i++) A ><
{ 8R"c}87
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >%5Ld`c:SD
//Utility.log(in.readLine()); Tt#4dm-
sHeader=httpConnection.getHeaderFieldKey(i); \,)('tUE
if(sHeader!=null) /]m5HW(P7K
{ 6r{NW9y'
if(sHeader.equals("Content-Length")) Ya{$:90(4
{ Bee`Pp2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jt5\
break; $(B|$e^:(
} \=PnC}7I
} P}hHx<L
else chk1tFV
break; &SuWmtq
} jsB%RvX
} %0l'Nuz
catch(IOException e){e.printStackTrace ();} *Z'*^Y1le
catch(Exception e){e.printStackTrace ();} ,]RMa\Q4Wg
*P2_l Q=
xa#;<8 iV
Utility.log(nFileLength); Qc1NLU9:
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return nFileLength; Em8q1P$tm>
} n4A_vz
"IQ' (^-P
f_v@.vnn.
//保存下载信息（文件指针位置） A)6xEeyR
private void write_nPos() +l'l*<
{ %gUf
try{ *|WS,
output = new DataOutputStream(new FileOutputStream(tmpFile)); DmzK* O{
output.writeInt(nStartPos.length); D>tex/Of3
for(int i=0;i<nStartPos.length;i++) }#%3y&7M7
{ $>^DkrOd
// output.writeLong(nPos); NMJX `
output.writeLong(fileSplitterFetch.nStartPos); \%&BK.t
output.writeLong(fileSplitterFetch.nEndPos); wJc~AP)I%z
} ^#-d^ )f;
output.close(); jlaU3qXL
} i/UDda"E
catch(IOException e){e.printStackTrace ();} M~'4>h}
catch(Exception e){e.printStackTrace ();} 0Va+l)F
} /`6Y-8e2
2IMU &
V9KI?}q:W
//读取保存的下载信息（文件指针位置） RHO|g0
private void read_nPos() ctg U
{ ]k+XL*]'A
try{ G-7!|&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Qc4r?7S<
int nCount = input.readInt(); ;IV
nStartPos = new long[nCount]; jGm`Qg{<
nEndPos = new long[nCount]; SXqWq
for(int i=0;i<nStartPos.length;i++) *Wbs{>&No
{ wPr9N}rf
nStartPos = input.readLong(); <O<Kf:i&c1
nEndPos = input.readLong(); Q[PVkZ
} vbA<=V*P
input.close(); ws/e~ T<c
} K Eda6zZH
catch(IOException e){e.printStackTrace ();} M[eq)a$
catch(Exception e){e.printStackTrace ();} FS'|e?WU
} TEJn;D<1I,
DsJ ikg(J
g2RrBK,
private void processErrorCode(int nErrorCode) gm^j8B
{ {beu
System.err.println("Error Code : " + nErrorCode); 7C;oMh5
} YL?2gBT
d9=i{i3
{UeS_O>(
//停止文件下载 jmORKX+)
public void siteStop() +DsdzR`Gx,
{ #}xw *)3
bStop = true; [,bra8f[C
for(int i=0;i<nStartPos.length;i++) !l(D0 C
fileSplitterFetch.splitterStop(); F>F2Yql&W
UWXl c
"1P[D'HV4|
} 42oW]b%P{;
} z@<OR$/`L
//负责部分文件的抓取 a Fh9B\n
**FileSplitterFetch.java n2V $dF4m
*/ vZiuElxKi
package NetFox; s'4O]k`
OH >#f6`[
$,.XPK5Qu
import java.io.*; ""f'L,`{.
import java.net.*; c80Ffq
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+dG3/vV
public class FileSplitterFetch extends Thread { c 8t
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String sURL; //File URL @=ro/.
long nStartPos; //File Snippet Start Position h`n) b
long nEndPos; //File Snippet End Position y9Q#%a8V
int nThreadID; //Thread's ID "Cz0r"N
boolean bDownOver = false; //Downing is over Q2>o+G
boolean bStop = false; //Stop identical @B`nM#X#
FileAccessI fileAccessI = null; //File Access interface S[;d\Z]~
=OeLF
fi~jT"_CI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yU"lJ>Eh}}
{ h-<Qj,L{W
this.sURL = sURL; ],~H3u=s3
this.nStartPos = nStart; 2C Fgit
this.nEndPos = nEnd; J#DN2y<
nThreadID = id; %<O0Yenu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~H c5M5m
} $KVCEe!X
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public void run() 7'!DK;=TD6
{ sj3[ny;b
while(nStartPos < nEndPos && !bStop) 5m yQBKE
{ y 2C Jk~
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sOO_J!bblP
try{ `]=0oDG:1!
URL url = new URL(sURL); FL{$9o\@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @R_ON"h
httpConnection.setRequestProperty("User-Agent","NetFox"); "s.hO0Z
String sProperty = "bytes="+nStartPos+"-"; W6s-epsRmT
httpConnection.setRequestProperty("RANGE",sProperty); Jr=XVQ(F
Utility.log(sProperty); c2u*<x
n%6ba77
\beYb0(+
InputStream input = httpConnection.getInputStream(); TT oW>RP#
//logResponseHead(httpConnection); T0{X,
BS=~G+/:|
z22:O"UHa
byte[] b = new byte[1024]; 9&bJ]
int nRead; '!F'B:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) NRT@"3,1YP
{ Pj1k?7
nStartPos += fileAccessI.write(b,0,nRead); }tO>&$ Z6f
//if(nThreadID == 1) ^fQa whub
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W9QVfe#s
} .^6yCs5~`
SZUo RWx
3lTnfc&
Utility.log("Thread " + nThreadID + " is over!"); L_tjclk0J
bDownOver = true; Us.k,
//nPos = fileAccessI.write (b,0,nRead); k;Fxr%
} 0YC|;`J
catch(Exception e){e.printStackTrace ();} F!fsW9
} cua( w
} (((|vI3 <
\&l@rMD3s
^zW=s$\Fo
//打印回应的头信息 B1A:}#
public void logResponseHead(HttpURLConnection con) qLPuKIF
{ pqTaN=R8
for(int i=1;;i++) eM@xs<BR
{ kA> e*6
String header=con.getHeaderFieldKey(i); "|Kag|(qB
if(header!=null) D"2bgw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s\< @v7A
Utility.log(header+" : "+con.getHeaderField(header)); CDPu(,^
else 6Jq3l_
break; >?#zPweA
} r@}8TE*|P
} \8g= Ix
~(#iGc]7
M!D6i5k,
public void splitterStop() U~d%5?q
{ GKKDO+A=!
bStop = true; CvR-lKV<
} }KO <II
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1:r#m- \
} \._|_+HiW
pSI8"GwQ
vvu $8n
/* |?]doBm|
**FileAccess.java , 6Jw
*//文件访问(定位，写) 4U16'd
package NetFox; 4*D"*kR;
import java.io.*; $ai;8)C6
Rt:^'Qi$!
]G D` f
public class FileAccessI implements Serializable{ )\j dF-s
CZ'm|^S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g~$UU(HX
RandomAccessFile oSavedFile; n @,.
long nPos; f$tm<:)Y
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J .VZD
public FileAccessI() throws IOException awI{%u_(nA
{ rL&Mq}7QK
this("",0); 3m9b
} i(OeE"YA
l^$'6q"
}%-iJ\
public FileAccessI(String sName,long nPos) throws IOException =R~zD4{"
{ #vhN$H:&q
oSavedFile = new RandomAccessFile(sName,"rw"); QxN1N^a0
this.nPos = nPos; ]31=8+D
oSavedFile.seek(nPos); 6Ol9P56j
} kN78j
3!osQ1
}r!+wp
public synchronized int write(byte[] b,int nStart,int nLen) Wy*+8~@A
{ <,rOsE6
int n = -1; 77y+ik
try{ <9piKtb|L
oSavedFile.write(b,nStart,nLen); dq`{fqGl
n = nLen; 7Xu#|k
} {=?(v`88
catch(IOException e) }]PHE(}7
{ \@WVeFr
e.printStackTrace (); HZZZ [km
} $A-X3d;'\/
""XAUxo
gBi3^GxjM?
return n; eBs.RR ]O
} hc+B+-,
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-egnMc67
} 1}c'UEr%)
U1X"UN)
)\ceanS
/* DKu$u]Z
**SiteInfoBean.java <Q/)SN6_E
*/ ~/9RSdv7
package NetFox; e\cyiW0
ruvfp_:
BZHoRd{EH
public class SiteInfoBean { !5C"`@}q>
}O>1tauI
cS7\,/4S
private String sSiteURL; //Site's URL 7/51_=%kR
private String sFilePath; //Saved File's Path _1qR1<V
private String sFileName; //Saved File's Name }O $]xB
private int nSplitter; //Count of Splited Downloading File 7xv9v1['
n#b{
?z#*eoPr
public SiteInfoBean() qar{*>LCG
{//nSplitter的缺省值为5 f"P866@oWn
//default value of nSplitter is 5 #gO[di0WhC
this("","","",5); ~M-L+XZl(
} xh$yXP0/
&C+2p
[B+F}Q^;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Yq6 @R|u
{ Y;_F,4H
sSiteURL= sURL; qb=2J5su
sFilePath = sPath; GI/NouaNfm
sFileName = sName; r8:"\%"f>
this.nSplitter = nSpiltter; xS tsw5d
T`fT[BaY
<_<zrXc]
} \f? K74
=3QhGFd
ocW~I3
public String getSSiteURL() D^6iQW+.P
{ LdG?kbJ&y
return sSiteURL; 3kC|y[.&
} $Y_S`#c@i
pXO09L/nv
U|tacO5w`
public void setSSiteURL(String value) I<D7Jj
{ /qy6YF8;y
sSiteURL = value; 6`Tx meIP
} mz6]=]1w
7WS$fUBi
SR?mSpq5
public String getSFilePath() NL$z4m0
{ ;!S5P(
return sFilePath; n({%|O<|
} 8Lx/ZGy
,4t6Cq!
*{#C;"
public void setSFilePath(String value) 4h|*r !
{ 1gkpK`u(B
sFilePath = value; rIcgf1v70
} AaA!U!B
S._2..%G
.(q'7Q Z/
public String getSFileName() sk39[9
{ 3{?X>6T
return sFileName; -_t4A *
} d=^QK{8
!;|#=A9
["Ts7;q9[
public void setSFileName(String value) K*T^w3=
{ %_5#2a
sFileName = value; -fFtHw:kHh
} bpZA%{GS
U&BCd$
6WZffB{-TK
public int getNSplitter() (@XQ]S}L
{ &mVClq
return nSplitter; 6H'A]0
} "NA<^2W@J
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4RVqfD
public void setNSplitter(int nCount) mTtaqo_Bh
{ P'tXG
nSplitter = nCount; ,M{G X
} v%cCJ SO#
} xA7~"q&u
PF/K&&9}
l%_K$$C
/* VBi gUK4
**Utility.java 3f^Pr
*/ J";N^OR{A%
package NetFox; bVU4H$k
>"!ScYn
&^#iS<s1
public class Utility { d"Zu10
v%T'!(0j/
tWy.Gz\
public Utility() EB!ne)X
{ 37kFbR@x
i \NV<I
Ny7*MZ-
} WC<[<uI*
TSewq4`K
//线程睡眠 7d%x7!E
public static void sleep(int nSecond) 0ex.~S_Oj4
{ 7\%JJw6h
try{ 3E;@.jD
Thread.sleep(nSecond); uT,i&
} 1-E6ACq
catch(Exception e) K0( S%v|,}
{ q]OIP"yv
e.printStackTrace (); n?cC]k;P~
} ZAfuW^r
} x@q.u3o9
hJ ^+asr
//日志 W{'hn&vU
public static void log(String sMsg) {Cm!5QYy
{ `$JvWN,kB
System.err.println(sMsg); EP@u4F
} W !j-/ql
\;N+PE
Vxap+<m
public static void log(int sMsg) 9pnOAM}
{ }p6]az3
System.err.println(sMsg); Jyg1z,B <
} {H[N|\
} lfDd%.:q4S
M^oL.'
L>IP!.J]?
/* nm#23@uZ4K
**TestMethod.java hQx*#:ns
*/ `ZEFH7P
package NetFox; D^O[_/i&
zs]ubJC@
h+B7BjA>G
public class TestMethod { 2{=D)aC$f
?:9y !Q=
vVo'f|fW
public TestMethod() u]NsCHKlT
{ ///xx/weblogic60b2_win.exe i kfJ!f
try{ C <:g"F:k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); neM)(` gp
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8[J%TWq%9
SiteFileFetch fileFetch = new SiteFileFetch(bean); VC/n}7p
fileFetch.start(); L@T/4e./
} sG#Os
catch(Exception e){e.printStackTrace ();} 7I w^
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eG(YORkR
} m-uXQS^@G
KdozB!\
j}.gK6Yq*
public static void main(String[] args) :a)RMp+^0
{ S\N l|U[
new TestMethod(); J&\Q3_vro9
} `uPO+2
} wwdmz;0S
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