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)); ){wE)NN
} }O!LTD
for(int i=0;i<nEndPos.length-1;i++) RS$:]hxd>_
{ l'o'q7&=z
nEndPos = nStartPos[i+1]; )IhI~,0Nmj
} t`Hwq
nEndPos[nEndPos.length-1] = nFileLength; g4-HUc zk
} !5{t1 oJ
} C\fc 4
.m+KXlP
8{h:z 9]J
//启动子线程 P/ug'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *.Kc-f4mP
for(int i=0;i<nStartPos.length;i++) m >'o&Hj
{ -5E%f|U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .}z&$:U9[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *8MU,6
nStartPos,nEndPos,i); &&t4G}*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Zcf?4{Kd?
fileSplitterFetch.start(); fe&K2C%bm
} 1Z*-@%RX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r,0> 40^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }_Jai4O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C' ny 2>uA
nEndPos = " + nFileLength); 3+(Fq5I
// fileSplitterFetch[nPos.length-1].start(); ;O.U-s
s%p(_pB
g*!2.P
//等待子线程结束 3Vt-]DGX
//int count = 0; 7@C:4c@0
//是否结束while循环 V!~uGf
boolean breakWhile = false; 8$@gAlI^
x{IOn;>R
[}+ MZ
while(!bStop) ("IRv>} 0
{ 9jJ&QACn
write_nPos(); b vUYLWzS
Utility.sleep(500); Y[*z6gP(
breakWhile = true; ~|fd=E%
|-2,k#|
>#xpg&2x
for(int i=0;i<nStartPos.length;i++) .D>%-
{ GHH1jJ_[7
if(!fileSplitterFetch.bDownOver) @hg1&pfxZ<
{ nh,N(t9
breakWhile = false; 7GE.>h5
break; MW`q*J`Yo
} X}g!Lp
} ^d4#
if(breakWhile) 5C2 *f4|
break; /Nb&e
.4.zy]I
=>/aM7]
//count++; !QP~#a%
//if(count>4) ])T*T$u
// siteStop(); O@?? NF6G
} mp!6MOQ
yO$]9
+9,"ne1'e
System.err.println("文件下载结束！"); 64`V+Hd
} 8?P@<Do%
catch(Exception e){e.printStackTrace ();} iK'bV<V&7
} k`kmmb>
-F@Rpfrj_#
s+o/:rrxY
//获得文件长度 6z!?U:bT
public long getFileSize() uppA`>
{ 9LzQp`In
int nFileLength = -1; #![b9~%WTh
try{ 0|P RCq
URL url = new URL(siteInfoBean.getSSiteURL()); rhwY5FD?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -=O9D-x=
httpConnection.setRequestProperty("User-Agent","NetFox"); o#H"tYP
'mG[#M/Y
~h tV*R
int responseCode=httpConnection.getResponseCode(); /dhw~|
if(responseCode>=400) 8X[G)J;
{ :Uj+iYE8Z8
processErrorCode(responseCode); B k#68p
return -2; //-2 represent access is error w/E4wp
} jZ7#xRt5w
doVBVTk^
Gb~*[
String sHeader; 69TQHJ[
M*}C.E!
*ZF7m_8u{
for(int i=1;;i++) "JKrbgN@;L
{ =H3 JRRS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v8Bi1,g
//Utility.log(in.readLine()); 2*F["E
sHeader=httpConnection.getHeaderFieldKey(i); aKkQXq*
if(sHeader!=null) F+v?2|03
{ wT3QSJ
if(sHeader.equals("Content-Length")) _:?)2NV
{ \y"!`.E7\d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i~PN(h
break; OjJKloy'
} MjQKcL4%7
} Uw)?u$+ P
else Dwe_ytjpc
break; O>lF{yO0`
} +_3>T''_
} :|EM1-lwf
catch(IOException e){e.printStackTrace ();} E<>n0",
catch(Exception e){e.printStackTrace ();} 90Jxn'>^
& 2& K9R
v@&&5J|
Utility.log(nFileLength); ?9i 7w1`
kQRNVdiz
pMHY2t
return nFileLength; /g< T)$2
} Azxy!gDT"
ZUVk~X3
*+vS f7
//保存下载信息（文件指针位置） /9/=]
private void write_nPos() X48Q{E+
{ vA10'Gx'
try{ V)^nVD)e
output = new DataOutputStream(new FileOutputStream(tmpFile)); jt@k<#h~
output.writeInt(nStartPos.length); RM|<(kq
for(int i=0;i<nStartPos.length;i++) ]HgAI$aA,
{ 5Y"JRWC
// output.writeLong(nPos); 7N+No.vR.
output.writeLong(fileSplitterFetch.nStartPos); J0~Ha u
output.writeLong(fileSplitterFetch.nEndPos); 6! \a8q'z
} T+8F'9i`
output.close(); WFocA:
} (x2I*<7P
catch(IOException e){e.printStackTrace ();} KA#4iu{
catch(Exception e){e.printStackTrace ();} Z,.*!S=?h
} Y?=+A4v
BI?M/pIm
40<ifz[7
//读取保存的下载信息（文件指针位置） cfyN)#9
private void read_nPos() lY yt8H
{ 4E}]>
try{ ]O3[Te
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (y7U}Sb'
int nCount = input.readInt(); \::<]
nStartPos = new long[nCount]; oIdMDp^$
nEndPos = new long[nCount]; 0.4c|-n
for(int i=0;i<nStartPos.length;i++) IKb 7#Ut
{ v4kk4}lE
nStartPos = input.readLong(); &EYO[~D06
nEndPos = input.readLong(); ):E4qlB
} /Li?;H
input.close(); :(VD<"X
} g!(j.xe
catch(IOException e){e.printStackTrace ();} ZC'(^liAp
catch(Exception e){e.printStackTrace ();} LGGC=;{}
} JeU|e$I4>
K]yCt~A$
!run3ip`Z
private void processErrorCode(int nErrorCode) ?ntyF-n&
{ NdZv*
System.err.println("Error Code : " + nErrorCode); 8q{ %n
} Zmw'.hL
g|tnYN
~,Ck
//停止文件下载 r'wam]1Z
public void siteStop() f8'D{OP"G
{ *[t@j*al
bStop = true; vG`R.
for(int i=0;i<nStartPos.length;i++) |f;u5r!^=
fileSplitterFetch.splitterStop(); fmILkXKz
N1`/~Gi
Wg9q_Ql
} (E )@@p7,:
} NitWIj[U;
//负责部分文件的抓取 IFYGl
**FileSplitterFetch.java Vi[* a
*/ vzA)pB~;
package NetFox; 9ar+Ph@*
]p~w`_3v
JK34pm[s
import java.io.*; Hz&a~
import java.net.*; e$}x;&cQ
//S/pCqED
GZ( W64
public class FileSplitterFetch extends Thread { AAUFX/}8P
J@ZIW%5
=[k9{cVW
String sURL; //File URL ;dWqMnV
long nStartPos; //File Snippet Start Position >'T%=50YH
long nEndPos; //File Snippet End Position A|&EI-In
int nThreadID; //Thread's ID zyR pHM$E
boolean bDownOver = false; //Downing is over f@}(<#
boolean bStop = false; //Stop identical wd]Yjr#%Ii
FileAccessI fileAccessI = null; //File Access interface PT4`1Oy}/1
p>zE/Pw~
H{XW?O^@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CeJ|z{F\
{ oD8-I^
this.sURL = sURL; j>T''Tf
this.nStartPos = nStart; hlFU"u_
this.nEndPos = nEnd; -ouJf}#R
nThreadID = id; {]\uR-a(o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NB5L{Gf6-
} udD*E~1q
U.Chf9a-
M.:@<S
public void run() #/t>}lc
{ aC yb-P
while(nStartPos < nEndPos && !bStop) K-5"#
{ V> a3V'
KPjqw{gR_R
3cfZ!E~^kc
try{ |g\.5IM#W
URL url = new URL(sURL); &lh_-@Xz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OpbT63@L
httpConnection.setRequestProperty("User-Agent","NetFox"); GQ-e$D@SfB
String sProperty = "bytes="+nStartPos+"-"; 0Dm`Ek3A7x
httpConnection.setRequestProperty("RANGE",sProperty); )_b@~fC
Utility.log(sProperty); 2gL[\/s
^dUfTG9{
fteyG$-s
InputStream input = httpConnection.getInputStream(); S?nNZW\6[
//logResponseHead(httpConnection); 0J:U\S
Ag>>B9
b*FU*)<4.
byte[] b = new byte[1024]; :,^>d3k
int nRead; !W~<q{VTs
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R04J3D|
{ @[v8}D
nStartPos += fileAccessI.write(b,0,nRead); ]Uh1l.O
//if(nThreadID == 1) )$_,?*fq:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gc,Ps
} ;RHNRVP
F~R7~ZE
4|f}F
Utility.log("Thread " + nThreadID + " is over!"); " '[hr$h3
bDownOver = true; 7=3O^=Q^Q
//nPos = fileAccessI.write (b,0,nRead); Bm}iU~(Z`
} 'Sa!5h
catch(Exception e){e.printStackTrace ();} &D*8l?A/1f
} u*2JUI*
} IN_gF_@%
+*.1}r&
&h(g$-l?[
//打印回应的头信息 "i%jQL'.
public void logResponseHead(HttpURLConnection con) JJ-i_5\q
{ Noz&noq
for(int i=1;;i++) enumK\
{ s5AgsMq
String header=con.getHeaderFieldKey(i); {:)vwUe{
if(header!=null) 8Zw]f-5x\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >UWStzH<
Utility.log(header+" : "+con.getHeaderField(header)); u>o<tw%Y
else +'%\Pr(
break; X" \}sl5
} G#lg|# -#
} Nb1J ~v
<4f,G]UH_
i|4_m
public void splitterStop() >BJ}U_ck
{ (I~\,[
bStop = true; 9U'[88
} l&|)O6N
NjP ]My
F.0d4:A+
} 7&#m]t^^
.YC;zn^
k*Pz&8|
/* D$hQyhz'
**FileAccess.java qHJ'1~?q
*//文件访问(定位，写) g}r^Xzd;
package NetFox; ?l9=$'
import java.io.*; 50,Y
Ut_mrb+W
+V1}@6k :
public class FileAccessI implements Serializable{ R,b59,&3/
^ $wJi9D6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {+\'bIV[
RandomAccessFile oSavedFile; `j:M)2:*y
long nPos; 0I^Eo|
u<kD}
Mciq-c)
public FileAccessI() throws IOException 6l[G1KkV
{ 0Ve%.k
this("",0); XNlhu^jh
} 6F-JK1i
((cb4IX
K7Gm-=%
public FileAccessI(String sName,long nPos) throws IOException ?[|hGR2L
{ 6V P)$h8
oSavedFile = new RandomAccessFile(sName,"rw"); ]738Z/)^
this.nPos = nPos; C#$6O8O
oSavedFile.seek(nPos); LfllO
} 4Cd#sQ
cUsL6y
48k7/w\
public synchronized int write(byte[] b,int nStart,int nLen) (Com,
{ ^Xa*lR 3
int n = -1; :ol6%Z's
try{ WvbEh|y
oSavedFile.write(b,nStart,nLen); VY_f =
n = nLen; FF3&Y^+^"
} 8sWr\&!
catch(IOException e) 6y9C@5p}B
{ /.2qWQH
e.printStackTrace (); /W0E(8:C)
} Oj-r;Tt_G}
@`Wt4<
`[bJYZBc2
return n; Q ]0r:i= .
} 5y}BCY2=/
2!idy]vy_
}+_9"YQ:
} (FG^UA#'
,m3":{G:t.
7O9n!aJ
/* "4RQ`.SR
**SiteInfoBean.java H@4/#V|Uy
*/ Tm\OYYyk
package NetFox; iU XM(]
!h*B (,
?lyltAxs'
public class SiteInfoBean { ^6#-yDZC@
DUhT>,~]
VRB~7\A5<)
private String sSiteURL; //Site's URL s_v}=C^
private String sFilePath; //Saved File's Path EzUPah
private String sFileName; //Saved File's Name W.p66IQwL&
private int nSplitter; //Count of Splited Downloading File d9|T=R
mQL8QW[c
FTbtAlqh<
public SiteInfoBean() W%WC(/hor
{//nSplitter的缺省值为5 smbUu/
//default value of nSplitter is 5 `T`c@A
this("","","",5); @~hz_Nm@8
} x.o3iN[=
g&XhQ.aa
t+J)dr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p8_2y~!
{ [m %W:Ez
sSiteURL= sURL; tbY SK
sFilePath = sPath; E::<;9
sFileName = sName; o:4CI
this.nSplitter = nSpiltter; [C2kK *JZ
\DaLHC~
P$Axc/H
} gn364U a
6Z$b?A3zM
sC9-+}
public String getSSiteURL() YyG~#6aCh
{ _m" ^lo
return sSiteURL; b6]e4DL:R
} XQ4dohGCP
-GK'V
9W$mDw6f
public void setSSiteURL(String value) aam1tm#Q
{ #.~.UHt
sSiteURL = value; vrQFx~ZztH
} k-io$
K7+^Yv\YQx
)\(lg*?:
public String getSFilePath() F>TYVxQ
{ #%;<FFu\
return sFilePath; dy'X<o^?W
} 38<~R
g<0w/n!jmC
H7y&N5.V
public void setSFilePath(String value) Feh"!k <6k
{ O\3r%=TF
sFilePath = value; 5c*p2:]
} kbD*=d}3{
3x,Aczb
?&{S~[;l
public String getSFileName() fMgcK$
{ Xqc'R5Cw
return sFileName; S83]O!w0
} $:xF)E
z<FV1niE
_-g-'Hr+N
public void setSFileName(String value) .LWOM8)
{ FZM ]o
sFileName = value; {yGZc3e1j
} !E4E'I=]N
8L%%eM_O
Lw!?T(SK
public int getNSplitter() %V@Rk.<
{ Q=)"om
return nSplitter; a15,'v$O
} #L|JkBia
MoC*tImWR
oHYD_8'f
public void setNSplitter(int nCount) MYur3lj%_
{ GGFar\ EzW
nSplitter = nCount; O('i*o4!}
} o06A=4I
} qk"oFP6
XhJP87A
yfRUTG
/* M6@'9E]|>
**Utility.java zsR wF
*/ k)<~nc-
package NetFox; 6qz!M
S,d ngb{
[Gh%nsH
public class Utility { Wwa41z
eG[umv.9b
< -@,
public Utility() n $D}0wSM/
{ 1FXzAc(c!
/ h2*$
~T;ajvJ
} 3:02`;3
;f\R$u-
//线程睡眠 \'}/&PCkr
public static void sleep(int nSecond) 5 b#" G"
{ i;uG:,ro
try{ >8F{lbEe
Thread.sleep(nSecond); FrAqTz
} .:r2BgL
catch(Exception e) 4N%2w(,+8
{ Qw{\sCH>
e.printStackTrace (); .SRuyioF&
} a|]%/[G@
} l1iF}>F2
*x#&[>
//日志 w#gU1yu
public static void log(String sMsg) tnKpn-LPA
{ J _[e9
System.err.println(sMsg); 5qeS|]^`
} tc49Ty9$[
hsQrd%{f
cQ8$,fo
public static void log(int sMsg) fjK]m.w
{ B1i!te}*
System.err.println(sMsg); 2A18hP`^
} {TxVRpiP{Z
} 71n uTE%!
O>"r. sR
y uK5r
/* Fh!!T%5>C
**TestMethod.java Ivl^,{4
*/ G+QNg.pH
package NetFox; G~iYF(:&
ym,Ot1
.KwuhmR
public class TestMethod { PE6u8ZAb"
,j(p}t
-R8!"~o
public TestMethod() (J;zkb
{ ///xx/weblogic60b2_win.exe lWyP[>*
try{ )zc8bS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gkq RO19
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "<n"A7e
SiteFileFetch fileFetch = new SiteFileFetch(bean); %OfDTs
fileFetch.start(); HV.|Eh_7
} ??e#E[bI
catch(Exception e){e.printStackTrace ();} c:,{O0 #
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__zu-!v
} &+w!'LSaD
3=L1HZH
F~@1n,[
public static void main(String[] args) =iN_Ug+
{ o)'=D(
new TestMethod(); ;KZ2L~ THG
} WZ V*J&
} \,IDLXqp
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