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)); dIo|i,-
} nAp7X-t
for(int i=0;i<nEndPos.length-1;i++) "p\XaClpz
{ N3};M~\
nEndPos = nStartPos[i+1]; adJoT-8P6
} 2rw<]Ce
nEndPos[nEndPos.length-1] = nFileLength; Wsr #YNhx|
} W&>+~A
} pP'-}%
eXU;UO^
DT=!
//启动子线程 `f:5w^A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; a`w)awb
for(int i=0;i<nStartPos.length;i++) Kup-O u,
{ /rNY;qXM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !HXdUAKu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +M\*C#
nStartPos,nEndPos,i); L#e|t0'#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BX),U
fileSplitterFetch.start(); tc{23Rf%
} Mdh(Mp(w
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _OF8D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2#Au6BvX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "gCSbMq(Vq
nEndPos = " + nFileLength); B(MO!GNg=
// fileSplitterFetch[nPos.length-1].start(); nDvny0^a
]sjOn?YA+
2="C6 7TK
//等待子线程结束 'FBvAk6
//int count = 0; tE{7S/?h
//是否结束while循环 l!ye\
boolean breakWhile = false; iR#jBqXD
,gU9ywg
&%Hj.
while(!bStop) 'ce9v@(0
{ $`'^&o;&f
write_nPos(); <,0&Ox
Utility.sleep(500); tS2lex%
breakWhile = true; eT+MN`
?<w +{
"VWxHRVg4M
for(int i=0;i<nStartPos.length;i++) r/Pg,si
{ +V|]:{3W
if(!fileSplitterFetch.bDownOver) /$rS0@p
{ @fpxGMy&
breakWhile = false; "`:#sF9S
break; )m[!HE`cZ
} PyHE>C%
} d*3R0Q|#{
if(breakWhile) ?=IbiT
break; vfhip"1
&F#X0h/m=
I{cn ,,8
//count++; S0=BfkHi.
//if(count>4) *OF7{^~&
// siteStop(); 4r(rWlM
} l}AB):<Z
^:-%tpB#!
nTu"
System.err.println("文件下载结束！"); oS_p/$F,
} <R{\pz2w
catch(Exception e){e.printStackTrace ();} 8}\"LXRbo
} &P ;6P4x
ur#"f'|-
"<O?KO3K
//获得文件长度 ~[9 ]M)=O0
public long getFileSize() !9)*.9[8
{ n? s4"N6
int nFileLength = -1; 1xtbhk]D
try{ Vxgc|E^J
URL url = new URL(siteInfoBean.getSSiteURL()); ^U_jeAuk8[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6ldDt?iSg
httpConnection.setRequestProperty("User-Agent","NetFox"); fQx 4/4j
SwP h-6
b'-gy0
int responseCode=httpConnection.getResponseCode(); %n}]$ d
if(responseCode>=400) M(3E b;`
{ 6 *8Ge
processErrorCode(responseCode); gieX`}
return -2; //-2 represent access is error U |4%ydG
} K->p&6s
hcaH
%)aDh }
String sHeader; E0oJ|My
^$#Q_Y|
ac&tpvij
for(int i=1;;i++) o!H"~5Trv!
{ E>V8|Hz;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Vk_L*lcN
//Utility.log(in.readLine()); (~#PzE:
sHeader=httpConnection.getHeaderFieldKey(i); L,kF]
if(sHeader!=null) sU}e78mh
{ Z=H fOC
if(sHeader.equals("Content-Length")) i([A8C_A
{ mA>Pr<aV:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); MoFZ
break; |]]fcJOBP
} xjX5PQu
} WD)[Ac[
else Ql V:8:H$
break; er<~dqZ}]
} (Pu*[STTT
} /V*eAn8>
catch(IOException e){e.printStackTrace ();} tIvtiN6[|l
catch(Exception e){e.printStackTrace ();} 7PvuKAv?k
|F=^Cu,
O>>8%=5Q
Utility.log(nFileLength); yi%B5KF~Al
QWP_8$Q
&`%C'KZ
return nFileLength; ?D~uR2+Z
} PHOW,8)dZh
FQ4rA 4
0+H"$2/
//保存下载信息（文件指针位置） >%[W2L\'
private void write_nPos() @O(\TIg
{ UmJg-~
try{ HU'E}8%t6
output = new DataOutputStream(new FileOutputStream(tmpFile)); Gce_gZH7{
output.writeInt(nStartPos.length); j"dbl?og
for(int i=0;i<nStartPos.length;i++) <<xJ-N
{ e'?(`yW>
// output.writeLong(nPos); {oZ]1Qf_
output.writeLong(fileSplitterFetch.nStartPos); PQs9@]w[
output.writeLong(fileSplitterFetch.nEndPos); 2KX *x_-
} }$UFc1He\J
output.close(); I'j?T.
} }l2JXf55
catch(IOException e){e.printStackTrace ();} ':[y]ep(~|
catch(Exception e){e.printStackTrace ();} _8`|KY
} X3>(K1
bC{~/ JP
?:2Xh/8-
//读取保存的下载信息（文件指针位置） uJ$"2<O
private void read_nPos() SW=p5@Hy{
{ z(=:J_N
try{ MWuVV=rd8a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Tv KX8m"
int nCount = input.readInt(); aG ,uF
nStartPos = new long[nCount]; &V;a:
nEndPos = new long[nCount]; .6hH}BM
for(int i=0;i<nStartPos.length;i++) ^m7PXY
{ ,s)H%
nStartPos = input.readLong(); Psv!`K
nEndPos = input.readLong(); xWMMHIu
} kDKpuA!
input.close(); 3_>R's8P
} }0TY
catch(IOException e){e.printStackTrace ();} ?b0\[
catch(Exception e){e.printStackTrace ();} ,)RdXgCs
} 'K!kJ9oqe
8?$2;uGL
/IC'R"V a
private void processErrorCode(int nErrorCode) Zry>s0
{ 7MfT~v
System.err.println("Error Code : " + nErrorCode); ^/+sl-6/F
} g[$B90
Cr` 0C
Yc$|"to
//停止文件下载 fS~.K9
public void siteStop() 1m0':n Vdu
{ $1v5*E
bStop = true; 0v_8YsZ!`$
for(int i=0;i<nStartPos.length;i++) g DhwJks
fileSplitterFetch.splitterStop(); ![ QQF|
=bDG|:+
= `^jz}
} jmFN*VIL
} NR*SEbUU*
//负责部分文件的抓取 >g[W@FhT'k
**FileSplitterFetch.java QJ>>&`{,
*/ a:fHTU=\p
package NetFox; 2 zy^(%a
s:ruCS
J-}NFWR;t
import java.io.*; ~g{,W
import java.net.*; )=D&NO67Pq
_x!pMj(A
w#e'K-=
public class FileSplitterFetch extends Thread { [a3 0iE
(Ka#6
CytpL`&^]
String sURL; //File URL pR"qPSv'
long nStartPos; //File Snippet Start Position -db+Y:xUZ
long nEndPos; //File Snippet End Position Bag#An1
int nThreadID; //Thread's ID C gx?K]>y
boolean bDownOver = false; //Downing is over - -G1H
boolean bStop = false; //Stop identical <}%ir,8
FileAccessI fileAccessI = null; //File Access interface B /W$RcV
`T70FsSJ
Q-F9oZ*0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #-;BU{3*
{ G DV-wPX
this.sURL = sURL; "" U_|JH-
this.nStartPos = nStart; {9Y'v
this.nEndPos = nEnd; }]I?vyQ#V
nThreadID = id; $<v_Vm?6d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <IVz mzpL
} yShHFlO=
0REWbcxd"
sYXS#;|M
public void run() e@OA>
{ GHy#D]Z
while(nStartPos < nEndPos && !bStop) 'T[zh#v>S
{ f[IchCwX
sD8S2
guv@t&;t0
try{ 0R& U18)y
URL url = new URL(sURL); z(3"\ ^T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); akQH+j
httpConnection.setRequestProperty("User-Agent","NetFox"); vrzX%'
String sProperty = "bytes="+nStartPos+"-"; `xUPML-
httpConnection.setRequestProperty("RANGE",sProperty); _ ^{Ep/ME=
Utility.log(sProperty); f[b YjIX
T Rw6$CR
6<Z:Xw
InputStream input = httpConnection.getInputStream(); [fp"MPP3
//logResponseHead(httpConnection); blcKtrYg
LzRiiP^q
O@iW?9C+
byte[] b = new byte[1024]; ?^~"x.<nr
int nRead; yUO|3ONT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {ZXC%(u
{ oui!fTy
nStartPos += fileAccessI.write(b,0,nRead); L2'd sOn
//if(nThreadID == 1) prtxE&-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k`TJ<Dv;
} >|)0Amt
ImY.HB^&
FE}!bKh
Utility.log("Thread " + nThreadID + " is over!"); KeB4Pae|V
bDownOver = true; 4MJzx9#
//nPos = fileAccessI.write (b,0,nRead); #-T.@a1X
} /BM1AV{s6
catch(Exception e){e.printStackTrace ();} +ZKhmb!
} iwQ-(GjM[A
} "Vq]|j,B/c
\'Ta8
zU~..;C
//打印回应的头信息 <im<(=m9
public void logResponseHead(HttpURLConnection con) vLuQe0l{
{ ;YDF*~9u
for(int i=1;;i++) |A0$XU{
{ v9U(sEDq
String header=con.getHeaderFieldKey(i); 6;cY!
if(header!=null) Da[C'm=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); IY6_JGe_w
Utility.log(header+" : "+con.getHeaderField(header)); yvCR =C
else Jwd&[ O
break; T-C#xmY(
} toqzS!&.v
} .dT;T%3fO
xGfDz*t
R9h>I3F=c
public void splitterStop() {~fCqP.2
{ Cc)P5\jh
bStop = true; c1kxKxE
} ]<gCq/V#
5xDN&su
]TgP!M&q
} O}_a3>1DY
UMuuf6
EWIc|b:
/* 3]<re{)J9O
**FileAccess.java *frJ^ Ws{
*//文件访问(定位，写) liqR#<
package NetFox; iN_D8dI
import java.io.*; =5~F6to
<m,yFk
,|X+/|gm
public class FileAccessI implements Serializable{ 3g[j%`k
p*`SGX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^Opy6Bqb
RandomAccessFile oSavedFile; GrR0RwnH)?
long nPos; tx5T^K7[
oNB,.:
?[VpN2*
public FileAccessI() throws IOException 8i;)|z7
{ ^Wfgwmh
this("",0); IT`=\K/[4
} kt{C7qpD
ZQ~myqx,+L
[W$Z60?RR
public FileAccessI(String sName,long nPos) throws IOException 6_<s=nTX
{ c~UAr k S
oSavedFile = new RandomAccessFile(sName,"rw"); i9eyrl+!
this.nPos = nPos; s S5fd)x
oSavedFile.seek(nPos); ydND$@; Z
} HNy/ -
x8?x/xE
5 n+ e
public synchronized int write(byte[] b,int nStart,int nLen) {kPe#n>xT
{ q{cp|#m#G
int n = -1; 3z)"U
try{ LxlbD#<V
oSavedFile.write(b,nStart,nLen); o}MzqKfu
n = nLen; Sf&?3a+f
} jD/7/G*
catch(IOException e) XDkS ^9
{ M6]0Y@@>
e.printStackTrace (); 6W;?8Z_1
} bugFl>
L; q)8Pb
:%#r.p"6x
return n; :vK(LU0K
} NdsX*o@a
?orhJS
5U{4TeUH
} -/UXd4S
R+E_#lP_$
DVl[t8K!
/* W&e'3gk_
**SiteInfoBean.java cRh\USS
*/ C~{NKMeC/m
package NetFox; K2xH'v O(
I{42'9
LiZdRr
public class SiteInfoBean { kxm:g)`=[
1GG>.RCP
^r>f2 x
private String sSiteURL; //Site's URL x^)g'16`
private String sFilePath; //Saved File's Path ^p 2.UW
private String sFileName; //Saved File's Name {b'}:aMc
private int nSplitter; //Count of Splited Downloading File 1xO!w+J#
)d}H>Qx=
ut4r~~Ar
public SiteInfoBean() v._Egk0
{//nSplitter的缺省值为5 %9T~8L @.
//default value of nSplitter is 5 SbS$(Gt#Bv
this("","","",5); u3Usq=Ij{
} hIVI\U,
3cOY0Z#T
jVad)2D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *%X6F~h(u
{ vZb|!#I
sSiteURL= sURL; -c+[6A>j
sFilePath = sPath; >-5td=:Z
sFileName = sName; Q`S iV
this.nSplitter = nSpiltter; V(;55ycr
m7r j>X Y
W?qpnPW
} x0\e<x9s
-uA3Y
Z}8k[*.
public String getSSiteURL() rH$eB/#F
{ =[]x\&@t
return sSiteURL; 1l/AKI(!
} 4>4V-m\
;w`sz.
=oE_.ux\
public void setSSiteURL(String value) 5LQk8NPh
{ JFkN=YR8
sSiteURL = value; FZe:co8Mu
} *.,"N}
O87"[c`>
{ p1lae
public String getSFilePath() v:rD3=M-
{ 6exI_3A4jh
return sFilePath; YBX)eWslK
} (U|)xA]y!
XC|*A$x,
)v%l0_z{
public void setSFilePath(String value) z,pNb%*O
{ -#LjI.
sFilePath = value; CO-Iar
} /8xH$n&xoC
N'I(P9@
TC qkm^xv
public String getSFileName() QVIcb;&:}
{ ,YjxCp3
return sFileName; u`'ki7LA
} >M?H79fF2s
!|:RcH[
7\mDBG
public void setSFileName(String value) 8h2D+1,PZC
{ OmB TA=E<
sFileName = value; ,H>W:O
} XZ.7c{B<
wJ6_I$>
:qxm !P
public int getNSplitter() RX:R*{]-
{ -Q6(+(7_|
return nSplitter; 9Ei5z6Vk/+
} N99[.mErU
^_@r.y]
=0,|/1~
public void setNSplitter(int nCount) ]?[zx'|
{ 2(pLxVl
nSplitter = nCount; R]Hz8 _X
} yahAD.Xuo@
} R.K?
Hi^35
*oCxof9JA
/* _B)s=Snx
**Utility.java 2Kjrw;
*/ hjkLVL
package NetFox; dUIqDl
8qn 9|
OY:u',T
public class Utility { >-b&v$
*-0>3
jh[ #p?:
public Utility() H"eS<eT
{ 13H;p[$
<PX.l%
>?z:2@Q)B
} H nK!aa
mjbTy"}"
//线程睡眠 $!f!,fw+
public static void sleep(int nSecond) IroPx#s:i
{ /0(%(2jIWl
try{ zX98c
Thread.sleep(nSecond); jgG$'|s}
} u^t$cLIZ
catch(Exception e) c&E]E(
{ 2`EVdl7B]
e.printStackTrace (); 1B 5:s,Oyj
} \wYc1M@7V
} qe<Hfp/p
q]CeD
//日志 1w`2Dt
public static void log(String sMsg) LT/mb2
{ S#tY@h@XV
System.err.println(sMsg); 6ZcXS
} oe9lF*$/
&:<, c12
"tUwo(K[
public static void log(int sMsg) hUh+JW
{ eTT)P
System.err.println(sMsg); h h"h j
} Fk{J@Y
} e4DMO*6
nob0T5G
M ,`w A
/* zEj#arSE4
**TestMethod.java ?E6^!4=,
*/ +1QK}H~
package NetFox; ;r.EC}>m
Lkn4<'un
-jB3L:
public class TestMethod { z8E1m"
];1R&:t
&kzj?xK=(j
public TestMethod() A (okv
{ ///xx/weblogic60b2_win.exe c+g@Z"es
try{ E;9>ePd@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &n:{x}Uc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9gy(IRGq/
SiteFileFetch fileFetch = new SiteFileFetch(bean); le8 #Z}p
fileFetch.start(); 2Q@Y^t
} y\D=Z N@
catch(Exception e){e.printStackTrace ();} <.bRf
1Ipfw
5pfYEofK[
} H>XFz(LWh
y!~qbh[
Be2lMC
public static void main(String[] args) p$Hi[upy
{ | &7S8Q
new TestMethod(); H;Ku w
} t0Mx!p'T
} -_em%o3XC
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