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)); Obg@YIwn
} }*ODM6
for(int i=0;i<nEndPos.length-1;i++) Z c<]^QR
{ A<;0L . J
nEndPos = nStartPos[i+1]; I &cX8Tw
} Cd9t{pQD4
nEndPos[nEndPos.length-1] = nFileLength; C*]AL/
} n\ Gg6Y
} T*p|'Q`
_dY:)%[]
o8mo=V4j
//启动子线程 =QTmK/(|B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v6KL93
for(int i=0;i<nStartPos.length;i++) }7&\eV{qU
{ 4Z],+?.[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H7J`]nr6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MXh^dOWR
nStartPos,nEndPos,i); =>.DD<g"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j@_nI~7f}
fileSplitterFetch.start(); r8<JX5zyuo
} {Wr\DVp
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Vzk cZK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B_b8r7Vn`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d[yrNB6|
nEndPos = " + nFileLength); r \9:<i8
// fileSplitterFetch[nPos.length-1].start(); cy9N:MR(c
cyDiA(ot&
~S!L!qY
//等待子线程结束 M$gvq:}kt
//int count = 0; # e$\~cPd
//是否结束while循环 M'b:B*>6
boolean breakWhile = false; ^v#+PyW
kaV%0Of]
}t}38%1i
while(!bStop) MyK^i2eD
{ -Zttj/K
write_nPos(); %{=4Fa(Jux
Utility.sleep(500); b,zR5R^D;
breakWhile = true; i:\bqK
6_pDe
pFS F[9?e>
for(int i=0;i<nStartPos.length;i++) $/MY,:*e
{ o&WRta>VP
if(!fileSplitterFetch.bDownOver) GsR-#tV@
{ a\.//?
breakWhile = false; d4[poi ~
break; 2f s9JP{^0
} aYqqq|
} 9Zs#Ky/
if(breakWhile) 4p*?7g_WVH
break; 32TP Mk
\-DM-NrZ1U
sTJJE3TBI
//count++; 1 VPg`+o
//if(count>4) U<1}I.hDJ
// siteStop(); ngtuYASc
} t- !h X/
aA7S'[NjB
Yjpb+}
System.err.println("文件下载结束！"); #tCIuQ,
} eOO!jrT:
catch(Exception e){e.printStackTrace ();} C+}CU}
} zUvB0\{q
Bb$S^F(Xq
Rv0-vH.n
//获得文件长度 W^-hMT]uD
public long getFileSize() hQ\#Fhu7
{ ]v/t8`
int nFileLength = -1; 39'X$!
try{ 7)g;Wd+H
URL url = new URL(siteInfoBean.getSSiteURL()); "4J?JR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wOD/Z8
httpConnection.setRequestProperty("User-Agent","NetFox"); oiIt3<BX
-i| /JH
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int responseCode=httpConnection.getResponseCode(); ?*B;514
if(responseCode>=400) )G}sb*+v?
{ 8 ))I$+
processErrorCode(responseCode); Ir'DA_..
return -2; //-2 represent access is error =>E44v
} H@VBP Q}Q
Y j,9V],
1c1e+H
String sHeader; EU`' 8*4
V3aY]#Su
B3ohHxHu
for(int i=1;;i++) (!^N~ =e;
{ q8&4=eV\A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H620vlC}V
//Utility.log(in.readLine()); |DdW<IT`0
sHeader=httpConnection.getHeaderFieldKey(i); .&aVx]
if(sHeader!=null) bcGn8
{ Y/QK+UMW*
if(sHeader.equals("Content-Length")) C?_t8G./_
{ &utS\-;G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LR 8e|H0
break; 1\"BvFE*E~
} 3hp tP
} P}w^9=;S
else o.v,n1Nm
break; Q*TQ*J7".X
} ]~4}(\u
} >2!^ dT^D
catch(IOException e){e.printStackTrace ();} 3|z;K,`Fw
catch(Exception e){e.printStackTrace ();} @U7U?.p
+btP]?04
}WBm%f
Utility.log(nFileLength); T%z!+/=&^
*X"F:7
2n"*)3Qj
return nFileLength; >?:i6&4o
} Qe'PAN=B
rzc 3k~@
% B7?l
//保存下载信息（文件指针位置） _.s\qQ
private void write_nPos() 72BzvY.
{ #UP,;W
try{ b*$o[wO9
output = new DataOutputStream(new FileOutputStream(tmpFile)); -NI@xJO4(;
output.writeInt(nStartPos.length); &**.naSo
for(int i=0;i<nStartPos.length;i++) DU*Hnii
{ exa}dh/uC
// output.writeLong(nPos); j[Hg]
output.writeLong(fileSplitterFetch.nStartPos); Lt#:R\;&
output.writeLong(fileSplitterFetch.nEndPos); Bk@_]a
} A=@V LU4%
output.close(); Ezo" f
} 3 8ls 4v3
catch(IOException e){e.printStackTrace ();} {#d`&]
catch(Exception e){e.printStackTrace ();} Jf8'N ot
} &El[
u8$~N$L
PhI{3B/
//读取保存的下载信息（文件指针位置） .*clY
private void read_nPos() 42H#n]Y
{ N-_| %C-.
try{ g*\v}6 h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pB{ f-M:D
int nCount = input.readInt(); b_"V%<I
nStartPos = new long[nCount]; |<5J
nEndPos = new long[nCount]; 07E".T%Ts
for(int i=0;i<nStartPos.length;i++) _3-,3ia
{ RvZryA*vu
nStartPos = input.readLong(); 'ra_Zg[j
nEndPos = input.readLong(); `cy"-CJS
} @b(gjOE
input.close(); d&3I>E$UP
} hKH Q!`&v
catch(IOException e){e.printStackTrace ();} Qr xO erp
catch(Exception e){e.printStackTrace ();} yp7,^l
} Phjf$\pt
|7 W6I$Xl
r>D[5B
private void processErrorCode(int nErrorCode) ]mDsUZf<
{ #|2g{7g*
System.err.println("Error Code : " + nErrorCode); o2t@-dNi
} 4$#ia F
9Y*VzQE
kA->xjk
//停止文件下载 DNTRLIKa
public void siteStop() 34&$_0zn
{ '@1Qx~*]e
bStop = true; B3i=pcef
for(int i=0;i<nStartPos.length;i++) q'U-{~q%
fileSplitterFetch.splitterStop(); 'e8d["N
EXScqGa]
,4?|}xg
} hJL0M!
} u8)r W
//负责部分文件的抓取 ;z=C^'
**FileSplitterFetch.java ^SelqX
*/ 6!Ap;O^*
package NetFox; yW7S }I
Y)-)NLLG;n
#'{PYr
import java.io.*; laIC}!
import java.net.*; PT5ni6
eWt>^]H~
E*#60z7F
public class FileSplitterFetch extends Thread { g\mrRZ/?
SGT-B.
"}Sid+)<
String sURL; //File URL ^a0-5
long nStartPos; //File Snippet Start Position gB'Ah-@,P
long nEndPos; //File Snippet End Position OEqe^``!
int nThreadID; //Thread's ID 97@?QI}
boolean bDownOver = false; //Downing is over QSQ\@h;E
boolean bStop = false; //Stop identical JT+lWhy
FileAccessI fileAccessI = null; //File Access interface $1`t+0^k
,)\5O0 D6
1x5CsmS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x'PjP1
{ 'jO-e^qT
this.sURL = sURL; J}`$WL:
this.nStartPos = nStart; )^a#Xn3z
this.nEndPos = nEnd; OCoRcrAx
nThreadID = id; _TeRsA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 EYj2h .k
} %QcG^R
g 0_r
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public void run() 2nz'/G
{ Q,+*u%/u
while(nStartPos < nEndPos && !bStop) Ih0>]h-7
{ Z`Eb L
eEb1R}@
F1]PYx$X
try{ YSUH*i/%
URL url = new URL(sURL); pzp"NKxi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Zvw3C%In
httpConnection.setRequestProperty("User-Agent","NetFox"); 9MlfZsby
String sProperty = "bytes="+nStartPos+"-"; }qX&*DU_@
httpConnection.setRequestProperty("RANGE",sProperty); AZ@Zo'
Utility.log(sProperty); Bwvc@(3v
q|_ 5@Ly
!ES#::;z?
InputStream input = httpConnection.getInputStream(); g KY ,G
//logResponseHead(httpConnection); wEn&zZjx
4BL,/(W] x
9fLP&v
byte[] b = new byte[1024]; h 7P?n.K
int nRead; [~%;E[ky$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V$%Fs{
{ ?;QKe0I^
nStartPos += fileAccessI.write(b,0,nRead); =1B&d[3;
//if(nThreadID == 1) 5/VB'N#7s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nylIP */
} A>,fG9pR
+mF 2yh
5m;wMW<
Utility.log("Thread " + nThreadID + " is over!"); zEL[%(fnc
bDownOver = true; Ljs(<Gm)-
//nPos = fileAccessI.write (b,0,nRead); m<HjL
} L&k$4,Z9
catch(Exception e){e.printStackTrace ();} }U1{&4Ph
} WmBnc#>gK
} x a,LV
?B4QTx9B
/9^0YC;Y*
//打印回应的头信息 S~9kp?kR$
public void logResponseHead(HttpURLConnection con) w3hL.Z,kV
{ G+yz8@
for(int i=1;;i++) ~_\2\6%1^n
{ ZuV
String header=con.getHeaderFieldKey(i); \) ONy9
if(header!=null) ?UZyu4O%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GM92yi!8
Utility.log(header+" : "+con.getHeaderField(header)); D#AxgF_He
else Sk%|-T(d$
break; Ceb i9R[
} n8ya$bc
} f }e7g d]M
I>zn$d*0
+Rd{ ?)2~
public void splitterStop() l3$?eGGM
{ p;01a
bStop = true; t`D@bzLC%
} ]8z6gDp
vDb}CQ\
pAL-Pl9z
} `-\JjMSQ1
\Vq;j 1
$e\R5Lu
/* 0]W/88ut*u
**FileAccess.java 4s2ex{$+MA
*//文件访问(定位，写) hkc_>F]Hx
package NetFox; aB_z4dqwU
import java.io.*; O&%T_Zk@@
ps J 1J
9e6{(
public class FileAccessI implements Serializable{ mw%_yDZ{
Z@umbyM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gQGiph |
RandomAccessFile oSavedFile; eT?LMBn\
long nPos; +t6m>IBu
t,YAk ?}
hY'%SV p
public FileAccessI() throws IOException ;sJ2K"c
{ <C xet~x
this("",0); W%:zvqg v
} f>PU# D@B
7 {<lH%Tn
(J#3+I
public FileAccessI(String sName,long nPos) throws IOException 4 ETVyK|
{ nwVtfsb
oSavedFile = new RandomAccessFile(sName,"rw"); ] lTfi0}g_
this.nPos = nPos; YiMecu
oSavedFile.seek(nPos); Hn.UJ4V
} yh!vl&8M
-|mRJVl8
[G)Sq;
public synchronized int write(byte[] b,int nStart,int nLen) tx-bzLo\
{ osI(g'Xb
int n = -1; )2hoO_l:
try{ wkw/AZ{27
oSavedFile.write(b,nStart,nLen); tam/FzVw
n = nLen; wxrT(x|
} Reo0ZU>
catch(IOException e) wtyu"=
{ e2F7G>q:5
e.printStackTrace (); Z2 4 m
} @x4Dt&:"
E$ rSrT(
W,+91rup
return n; aKO@_R,:
} VVOt%d
W=:+f)D
} U.B$4Q
} tDVdl^#
Uk4">]oct
8&bj7w,K
/* #U6qM(J
**SiteInfoBean.java ;C%EF
*/ 1C{n\_hR
package NetFox; +J9lD`z
&kBs'P8>
!8].Z"5J
public class SiteInfoBean { =%`"
zKr(Gt8
?;Qk!t2U
private String sSiteURL; //Site's URL :SGQ4@BV
private String sFilePath; //Saved File's Path O'(vs"eN
private String sFileName; //Saved File's Name &$f?XdZ7
private int nSplitter; //Count of Splited Downloading File 4YC`dpO'
dQb?Zi7g
9OBPFF
public SiteInfoBean() &rubA
{//nSplitter的缺省值为5 &9>d
//default value of nSplitter is 5 }z#8vE;
this("","","",5); 'cv/"26#
} bcG-js-
D?R z|
>%,tyJ~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W#Z]mt B
{ tK*f8X+q
sSiteURL= sURL; ^=j$~*(LmX
sFilePath = sPath; I5,Fh>
sFileName = sName; 3IIlAzne;
this.nSplitter = nSpiltter; z7o59&
o-_a0j
D6pk!mS
} Z)~2{)
_JS'~JO3{
$9/r*@bu8d
public String getSSiteURL() $}@ll^
{ Yc}b&
return sSiteURL; \T?O.
} .xx9tP}Xy
@B6[RZR
[sBD|P;M
public void setSSiteURL(String value) _=b[b]Ec$s
{ w# ['{GL
sSiteURL = value; Y9N:%[ :>W
} (;N_lF0
~JJv 2
*zcH3a,9"x
public String getSFilePath() `/O_6PQ}
{ NbdaP{{
return sFilePath; p|%)uA3'/
} JT+P>\\];'
{<lV=0]
N*#SY$!y
public void setSFilePath(String value) })Jp5vv
{ _]g6 3q
sFilePath = value; :n=+$Dq
} ;%}
,aeFEsi
q!n|Ju<
public String getSFileName() 4{V=X3,x
{ <Ip}uy[Y
return sFileName; O;~1M3Ii
} W$W7U|Z9y+
tF4"28"h
z|Xl%8
public void setSFileName(String value) LS`Gg7]S
{ oKUJB.PF
sFileName = value; hn-S$3')`
} ;rX4${h
X!m/I i$q
/T?['#:r-)
public int getNSplitter() hikun2
{ ji "*=i
return nSplitter; OP@PB|
} *m2:iChY
{r"HR%*u
Cpl\}Qn
public void setNSplitter(int nCount) lH[N*9G(
{ rfk';ph
nSplitter = nCount; QL3%L8
} #/aWGx_
} j JW0a\0
^U52 *6
S}>rsg!
/* lp6GiF
**Utility.java 7Y-GbG.'
*/ F~m tE8B:
package NetFox; g$ h!:wW
J;qHw[6
0F"xU1z,
public class Utility { j%lW+[%
B=f{`rM)~W
yuND0,e
public Utility() 3E#acnqn*
{ rl4-nA
_z_uz\#,
!cfn%+0
} B|8(}Ciqx
!!9V0[
//线程睡眠 R +k\)_F
public static void sleep(int nSecond) ^'}Td~(
{ h' 16"j>
try{ >y1/*)O9~
Thread.sleep(nSecond); wFh{\
} RxqXGM`4
catch(Exception e) IgVxWh#
{ ^OUkFH;dG?
e.printStackTrace (); Vry#
} `=oN&!
} M$w^g8F27H
aw(P@9]
//日志 DY1o!thz)
public static void log(String sMsg) bygwoZ<E
{ "UE'dWz
System.err.println(sMsg); UXd\Q''
} WHU&9N
.; :[sv)
)%*uMuF
public static void log(int sMsg) djk
{ ^CX~>j\(
System.err.println(sMsg); J=() A+
} uvT]MgT
} l?ofr*U&-x
DJeG
b.$Gc!g
/* =!7yX;|
**TestMethod.java {1FYHM^
*/ Zf|f $1-
package NetFox; JIK;/1
*F=wMWa
2Ddrxc>48
public class TestMethod { hF6EOCY6D
)4j#gHN\
/QTGZb
public TestMethod() ~dC^|
{ ///xx/weblogic60b2_win.exe )5B90[M|t
try{ =\tg$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); % nJ'r?+h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _,5(HETE2
SiteFileFetch fileFetch = new SiteFileFetch(bean); p3X>
fileFetch.start(); KVJiCdg-
} DI+kO(S
catch(Exception e){e.printStackTrace ();} -BR&b2
Ucv-}oa-?
HZR~r:_ i
} NX$$4<A1
"",V\m
-8g ;t3z
public static void main(String[] args) qW),)i
{ UAa2oY&
new TestMethod(); 2uz<n}IV
} HdLVXaD/
} Kx ';mgG#$
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