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)); @|;[ ;:h@
} 0Gj/yra9MO
for(int i=0;i<nEndPos.length-1;i++) ;Qy Ew5
{ ,X|FyO(p
nEndPos = nStartPos[i+1]; lI46 f
} \>4>sCC
nEndPos[nEndPos.length-1] = nFileLength; I!Dx)>E&
} !^Ay!
} -J!n7
aNM*=y`
!0^4D=dO
//启动子线程 zEQQ4)mA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [-Z 6QzT
for(int i=0;i<nStartPos.length;i++) ~i?Jg/qcxN
{ {R(/Usg!=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8yYag[m8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }JOz,SQHP
nStartPos,nEndPos,i); T-n>+G{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >r)UDa+
fileSplitterFetch.start(); rc:UG "[
} .z$UNB(!M
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9FC_B+7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M`#g>~bI#R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g<~ODMCO?W
nEndPos = " + nFileLength); sMAH;'`!Eu
// fileSplitterFetch[nPos.length-1].start(); \3(s&K\Y6\
{|%^'lS
zZ9Ei-Q
//等待子线程结束 i`6utOq
//int count = 0; G@e;ms1
//是否结束while循环 ve a$G~[%6
boolean breakWhile = false; =|O]X|y-lZ
[$$R>ELYQ
;=%cA#}_0
while(!bStop) IN;!s#cl:
{ MC-Z6l2
write_nPos(); uFuH/(}K[
Utility.sleep(500); U3aM^
breakWhile = true; ^eoW+OxH
\4G9fR4
#mM9^LJ
for(int i=0;i<nStartPos.length;i++) "a _S7K
{ (.z0.0W
if(!fileSplitterFetch.bDownOver) (0_]=r=q
{ pi;fu
breakWhile = false; bQ?Vh@j(M
break; <vs*aFq
} [$>@f{:
} $+{o*
if(breakWhile) BD.l5~:
break; ~y 2joStx
.ezko\nU
HWL? doM
//count++; Q[!?SSX%
//if(count>4) D!)h92CIDm
// siteStop(); KLj/,ehD !
} I?q- :9:
!t)uRJ
h^."wv
System.err.println("文件下载结束！"); +5GC?cW
} djdSD
catch(Exception e){e.printStackTrace ();} (:+Wc^0
} H?=[9?1wI5
Vn^8nS
Nhjz~S<o
//获得文件长度 bL:+(/:
public long getFileSize() je:J`4k$
{ vXSpn71Jb
int nFileLength = -1; d| {<SRAI
try{ vMXn#eR
URL url = new URL(siteInfoBean.getSSiteURL()); >G0ihhVt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MzW!iG
httpConnection.setRequestProperty("User-Agent","NetFox"); ;$r!eFY;
Pl|*+g
hz2f7g
int responseCode=httpConnection.getResponseCode(); WK SWOSJ
if(responseCode>=400) p|r>tBv?x
{ 5B{Eg?
processErrorCode(responseCode); +jGUp\h%9;
return -2; //-2 represent access is error 1x0)mt3
} 'Te'wh=Y
eYg0NEq{
0M}Ql5+h,
String sHeader; NA$ODK-
lb)i0`AN+
${UH!n{
for(int i=1;;i++) QSo48OFs
{ K!G/iz9SB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); BQ~\p\
//Utility.log(in.readLine()); K+U0YMRmz
sHeader=httpConnection.getHeaderFieldKey(i); i+Xb3+R
if(sHeader!=null) *^%ohCUi
{ AIwp2Fz
if(sHeader.equals("Content-Length")) < $rXQ
{ `b5pa`\4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ; JHf0
break; 4=;`\-7!
} #fF';Y7
} h`:gMhn
else wo) lkovd
break; _4t
} n6GB2<y
} 4V5h1/JPm
catch(IOException e){e.printStackTrace ();} eOd'i{f@F
catch(Exception e){e.printStackTrace ();} y-:d`>b>\
OmECvL'Z
[Kanj/
Utility.log(nFileLength); TP)}1@
#Bas+8 @,
4{=^J2z
return nFileLength; I6 Q{ Axy
} pU@&-
Ivc/g,
~jOk?^6
//保存下载信息（文件指针位置） y$HV;%G{26
private void write_nPos() +zsB~Vz
{ ,S=ur%
try{ s ` +cQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); CF@j]I@{
output.writeInt(nStartPos.length); 5+iXOs<
for(int i=0;i<nStartPos.length;i++) H_7EK
{ 32,Y3!%
// output.writeLong(nPos); 0\yA6`}!
output.writeLong(fileSplitterFetch.nStartPos); XXPpj< c
output.writeLong(fileSplitterFetch.nEndPos); R}cNhZC
} R7U%v"F>`
output.close(); ]Vmo>
} TQmrL
catch(IOException e){e.printStackTrace ();} d^J)Mhju
catch(Exception e){e.printStackTrace ();} -U\'Emu4
} #]6{>n1*+w
T=)qD2?
E3l*_b0
//读取保存的下载信息（文件指针位置） 1.+6x4%rV
private void read_nPos() 1]eRragm"
{ ;-XfbqZ\
try{ wMj#.Jh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); CGzu(@dd\
int nCount = input.readInt(); "TJ*mN.i{}
nStartPos = new long[nCount]; atF#0*e>
nEndPos = new long[nCount]; B~7!v${
for(int i=0;i<nStartPos.length;i++) g&y^r/
{ dzBP<Xyh
nStartPos = input.readLong(); huS*1xl
nEndPos = input.readLong(); b0YEIV<$
} W>i"p~!
input.close(); (S?Y3l|
} g_`a_0v
catch(IOException e){e.printStackTrace ();} ($kw*H{Ah^
catch(Exception e){e.printStackTrace ();} *<!q@r<d
} )0iN2L]U;
*;]}`r
_1&Ar4:
private void processErrorCode(int nErrorCode) ~bxev/$d
{ (nt`8 0
System.err.println("Error Code : " + nErrorCode); 4$[o;t>
} n\l?+)S *
gWGDm~+
No} U[u.O
//停止文件下载 z&tC5]#
public void siteStop() w|-3X
{ (X,i,qK/
bStop = true; jt on\9
for(int i=0;i<nStartPos.length;i++) w+R7NFq
fileSplitterFetch.splitterStop(); rO$pj~!|Q
(pd$?vRy
LCH\;07V#
} H{vKk
} ,M;9|kE*
//负责部分文件的抓取 L|T?,^
**FileSplitterFetch.java e))L&s
*/ 32<D9_
package NetFox; jRg gj`o
@%R4V[Lo.
@m9pb+=v
import java.io.*; 2CO/K_Q
import java.net.*; Z|uvrFa
MhD'
)*;Tt @'y
public class FileSplitterFetch extends Thread { &,k!,<IF
j#n ]q{s4
5]N0p,f
String sURL; //File URL ORs:S$Nt$
long nStartPos; //File Snippet Start Position d#rr7O
long nEndPos; //File Snippet End Position !H\oQv-I
int nThreadID; //Thread's ID <|}Z6Ti
boolean bDownOver = false; //Downing is over qY#*LqV
boolean bStop = false; //Stop identical T+}|$/Tv
FileAccessI fileAccessI = null; //File Access interface j2MA['{
9j>2C
-[7+g
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #cfiN b}GX
{ 4d@yAr}
this.sURL = sURL; #c^]p/
this.nStartPos = nStart; rUb{iU;~m
this.nEndPos = nEnd; 1'E=R0`pA
nThreadID = id; E(r_mF7:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _YF>Y=D-
} sm/aL^4
bkV<ZUW|;
!Ld5Y$
public void run() xSmG,}3mF
{ 2<EV iP9
while(nStartPos < nEndPos && !bStop) o72r `2
{ h+Co:pr
(u@:PiU/eP
XjGS.&'I
try{ +;KUL6
URL url = new URL(sURL); &jF'2D^_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ##rkyd
httpConnection.setRequestProperty("User-Agent","NetFox"); *4U_MM#rX
String sProperty = "bytes="+nStartPos+"-"; =0g!Q
httpConnection.setRequestProperty("RANGE",sProperty); Fc1!i8vv
Utility.log(sProperty); 4E^ ?}_$
m)tu~neM
0~qc,-)3
InputStream input = httpConnection.getInputStream(); S0^a)#D &
//logResponseHead(httpConnection); #DUfEZ
f*o
&>JP.//spi
byte[] b = new byte[1024]; QRQZ{m
int nRead; 6'Q{xJe?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7?Wte&C];p
{ SOOVUMj
nStartPos += fileAccessI.write(b,0,nRead); qIi \[Ugh
//if(nThreadID == 1) HOP*QX8C%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T8o](:B~
} "2cOSPpQL
:wC\IwG~CE
7iP+!e}$.
Utility.log("Thread " + nThreadID + " is over!"); uHgq"e
bDownOver = true; ~1uQyt
//nPos = fileAccessI.write (b,0,nRead); M=^d
} ZxF`i>/h
catch(Exception e){e.printStackTrace ();} eY<<Hld
} \Bo%2O%4
} 6'#5Dqw"r
;st0Ekni)
N:lfKI
//打印回应的头信息 C"I jr=w
public void logResponseHead(HttpURLConnection con) E4X6f
{ uM2@&)u
for(int i=1;;i++) N'`X:7fN
{ xKUL}>8
String header=con.getHeaderFieldKey(i); W"NI^OX
if(header!=null) [^qT?se{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >d + }$dB
Utility.log(header+" : "+con.getHeaderField(header)); Nfa&r
else M"3"6U/e
break; _**Nlp*%
} j,0`k
} 'UlVc2%{
d[a(uWEl
KQ\K:#
public void splitterStop() /qLO/Mim
{ #V>R#Oh}
bStop = true; T\l`Y-vu
} _;HdX$op
*9'3 `^l
0S{23L4C
} Hyb(.hlZh
@DysM~I
*&_*G~>D
/* tsb[=W!Ar8
**FileAccess.java PT/Nz+
*//文件访问(定位，写) $+4DpqJ
package NetFox; kdNo<x1o
import java.io.*; Y1PR?c Q
&L8RLSfX
\=%lH=yS
public class FileAccessI implements Serializable{ s)-oCT$[
9?l a5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5JzvT JMx
RandomAccessFile oSavedFile; VF?H0}YSHb
long nPos; KFrsXf
sfXFh
f}-'67*Y
public FileAccessI() throws IOException J^7m?mA
{ {$frR "K
this("",0); {)" 3
} KIF9[/P
wps/{h,
u&zY>'}zm
public FileAccessI(String sName,long nPos) throws IOException alb3oipOB
{ khy'Y&\F;
oSavedFile = new RandomAccessFile(sName,"rw"); a#p+.)Wm
this.nPos = nPos; Rta}*
oSavedFile.seek(nPos); o#qdgZ
} Sz0PZtJ
-@N-i$!;J
rL5=8l
public synchronized int write(byte[] b,int nStart,int nLen) _}R$h=YD
{ R~g|w4a@sC
int n = -1; ^+(5[z
try{ "tyRnUP
oSavedFile.write(b,nStart,nLen); h#0n2o#
n = nLen; i%i~qTN
} yY$^ R|t
catch(IOException e) ifn=De3+
{ LW1 4 'A}
e.printStackTrace (); HoQb.Z
} FvsVfV U
k3Yu"GY^
#BRIp(65-6
return n; N#u'SGTG
} u&~Xgq5[
<'=!f6Wh
f`qy~M&
} NO5k1/-
~n 'A1
+`>7cy%cZ
/* t'_EcYNS
**SiteInfoBean.java 2s}S9
*/ kff N0(MR
package NetFox; ILuQ.VhBVN
Fyvo;1a
!8@yi"n
public class SiteInfoBean { uEgR>X>
yi8vD~aA[
H;`F}qQ3
private String sSiteURL; //Site's URL gJ l^K
private String sFilePath; //Saved File's Path INndTF
private String sFileName; //Saved File's Name 19fa7E<
private int nSplitter; //Count of Splited Downloading File [Qs`@u<%
=z}PR1X!
;0eVE
public SiteInfoBean() 5AT^puL]]
{//nSplitter的缺省值为5 a 4?A 5
//default value of nSplitter is 5 qT?{}I
this("","","",5); !Yc:yF
} (aYu[ML
9d1km~
..yV=idI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :'DX M{
{ %;&lVIU0
sSiteURL= sURL; E$%v);u
sFilePath = sPath; ]]p\1G
sFileName = sName; 3nA^s"#p
this.nSplitter = nSpiltter; 59nRk}^$se
DT-.Gdb8
Q7x[08TI
} ";.j[p:gi
"'5(UiSFz
%Za}q]?
public String getSSiteURL() ?q6#M&|j/I
{ w,P@@Q E
return sSiteURL; i?^L",[
} mX|M]^_,z
&wi+)d
xn, u$@F
public void setSSiteURL(String value) {)Wf[2zJ
{ RrxbsG1HP
sSiteURL = value; -+F,L8
} ET^?>YsA
POk5+^
6EC',=)6R
public String getSFilePath() {5VJprTbv
{ :G6CWE
return sFilePath; RV]#Bg*[#
} @Yt394gA%\
}S iR;2W
oY~q^Y
public void setSFilePath(String value) hV $Zr4'
{ ta95]|z"j
sFilePath = value; ,~7~ S"
} g]j&F65D
6}Y==GPt
8$c)]Bv
public String getSFileName() wMkHx3XD
{ ]ovtH.y
return sFileName; RQ0^ 1 R
} kmW/{I9,ua
b7hICO-w
PM!JjMeQh
public void setSFileName(String value) 2aTq?ZR|8A
{ (6/aHSXI
sFileName = value; F u5zj\0J
} S?Cd,WxT
*_YH}U
<:AA R2=
public int getNSplitter() h}|.#!C3
{ <c5g-*V:
return nSplitter; kJ%a;p`O
} G5|nt#>
!pj&h0CR
3\]j4*i!
public void setNSplitter(int nCount) |;:Kn*0/]
{ cY+fZ=
nSplitter = nCount; kXdXyq
} pFs/ipZX^*
} W $mw9
gcI<bY
VI|2vV6?
/* tSni[,4Kq
**Utility.java [g`4$_9S
*/ ^7Z?}tgU
package NetFox; 16N|
6Ik v}q_j
daCkjDGl\
public class Utility { Hi2JG{i
_s<BXj
KXz7l\1Gb
public Utility() t%,:L.?J#
{ yD$d^/:
N,8.W"fV
3xRn
} |F\fdB}?S:
#zgO_H
//线程睡眠 )b%zYD9p
public static void sleep(int nSecond) 00SS<iX
{ J!|R1
try{ w`<{
Thread.sleep(nSecond); 9Y:.v@:}0
} F(/Ka@
catch(Exception e) ~-G_c=E?
{ zgGJ<=G.
e.printStackTrace (); }4piZ ch
} pKLNBR|
} `|&0j4(Pg
? 47"$=G
//日志 NBBR>3nt
public static void log(String sMsg) 'ahZ*@kr
{ fGA#0/_`
System.err.println(sMsg); <eS+3,
} j%ZBAk)}
Z<=L
\|B\7a'4
public static void log(int sMsg) {~#PM>f
{ p Djt\R<f
System.err.println(sMsg); 4$mtc*tzT
} wSM(!:on5
} Wwr
zmu+un"\j
y,OG9iD:h
/* ;;C2t&(
**TestMethod.java xDPR^xY
*/ WlW%z(RC
package NetFox; 0N]\f.=`
b>#=7;
7hLh}
public class TestMethod { .!+7|us8l\
sk:B;.z
Brd9"M|d
public TestMethod() py%~Qz%
{ ///xx/weblogic60b2_win.exe rXBCM
try{ /C<p^#g9.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xTH3g^E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i6P$>8jBQ-
SiteFileFetch fileFetch = new SiteFileFetch(bean); mQSn*;9\T3
fileFetch.start(); W|E %
} a2]ZYY`R7
catch(Exception e){e.printStackTrace ();} A>mk0P)~Q
E.0J94>iM
Jk7 Am-.0
} yc`3)
p&4n"hC
C9""sVs
public static void main(String[] args) *XYp~b
{ 6v3l^~kc'
new TestMethod(); F;ttqL
} RBrb7D{
} =Q(J!f
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