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.eQZ5n~q`
} iulM8"P
for(int i=0;i<nEndPos.length-1;i++) TL(L[
{ KYY~ YP
nEndPos = nStartPos[i+1]; v2 [ l$
} /ve8);cH\
nEndPos[nEndPos.length-1] = nFileLength; H"8+[.xBh
} kStWsc$;+T
} B[F,D
x,"'\=|s*
vB, X)
//启动子线程 hM2^[8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'j];tO6GfC
for(int i=0;i<nStartPos.length;i++) uQ#3;sFO
{ !8]W"@qb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GYot5iLg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %&9tn0B
nStartPos,nEndPos,i); v4sc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D,+I)-k<
fileSplitterFetch.start(); F7^d@hSV
} :Vq gmn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M:h~;+s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ow=`tv$l
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )K\w0sjR
nEndPos = " + nFileLength); = wNul"
// fileSplitterFetch[nPos.length-1].start(); Y[x9c0
['m@RJm+
W&y%fd\&3
//等待子线程结束 1tG,V%iCp
//int count = 0; %(b`i C9
//是否结束while循环 G8"L#[~
boolean breakWhile = false; )RlaVAtM
,WbO8#z+
mfLS</A
while(!bStop) .EGZv(rz&
{ EKf"e*|(L
write_nPos(); ^<xpp.eY
Utility.sleep(500); \}t(g}7T
breakWhile = true; `bO+3Y'5
Ps0'WRJnx
^lB'7#7
for(int i=0;i<nStartPos.length;i++) AEm?g$a
{ S|Wv1H>
if(!fileSplitterFetch.bDownOver) j2"jCv
{ nm66U4.@
breakWhile = false; <pRb#G"
break; J\XYUs
} )DuOo83n["
} ws4a(1
if(breakWhile) hRSRz5 J}
break; t#oJr2
eu~WFI
3]0ETcT
//count++; IZeWswz
//if(count>4) GEy^*, d
// siteStop(); 9>d$a2nc
} g+p?J.+
dkJ+*L5
)El#Ks5u
System.err.println("文件下载结束！"); axnkuP(
} 71nXROB
catch(Exception e){e.printStackTrace ();} $+zev$f
} %1a\"F![
hf>JW[>Xo
n_sCZ6uXEQ
//获得文件长度 o6
public long getFileSize() N54U [sy
{ 2@Jw?+}vr
int nFileLength = -1; |#$Wh+,*
try{ FVsVY1
URL url = new URL(siteInfoBean.getSSiteURL()); RvvK`}/6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q&^ti)vB
httpConnection.setRequestProperty("User-Agent","NetFox"); ]H) x
K[PIw}V$?:
\MQ|(
int responseCode=httpConnection.getResponseCode(); He. gl
if(responseCode>=400) "CBe$b4
{ Z.<OtsQN
processErrorCode(responseCode); t.c XrX`k
return -2; //-2 represent access is error zS18Kl
} j*<H18^G
v7T05
#rqLuqw
String sHeader; E"&fT!yi
z'3
2Q,e1'=
for(int i=1;;i++) M?x/C2|
{ |2AK~t|t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j%Y`2Ra
//Utility.log(in.readLine()); V9NE kS
sHeader=httpConnection.getHeaderFieldKey(i); &,2XrXiFu
if(sHeader!=null) 6<.Ma7)lA
{ i[H`u,%+(
if(sHeader.equals("Content-Length")) { :'#Ts<
{ `$SX%AZA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )FGm5-K@
break; 4]u53`
} NMM0'tY~
} w0x,~
else ?V"X=B2
break; >`Gys8T
} 3iJ4VL7
} Q3u P7j
catch(IOException e){e.printStackTrace ();} m^@,0\F
catch(Exception e){e.printStackTrace ();} c?"#x-<1s
5;oWFl
IM|VGT0
Utility.log(nFileLength); i-~HT4iw
z{Z'2,#
4*d$o=wa
return nFileLength; '@i/?rNi%N
} rR&;2
03L+[F&"?
.Ebg>j:\
//保存下载信息（文件指针位置） s6%%/|
private void write_nPos() ?<bByxa
{ SwpS6
try{ k?3NF:Yy7
output = new DataOutputStream(new FileOutputStream(tmpFile)); vdAaqM6D
output.writeInt(nStartPos.length); }p$>V,u
for(int i=0;i<nStartPos.length;i++) qasbK:}
{ xDG8C39qrs
// output.writeLong(nPos); gUwg\>UC
output.writeLong(fileSplitterFetch.nStartPos); b/HhGA0
output.writeLong(fileSplitterFetch.nEndPos); D/^yAfI
} ZH;VEX
output.close(); kL\ FY
} S*VG;m#
catch(IOException e){e.printStackTrace ();} ?%dsY\
catch(Exception e){e.printStackTrace ();} *,q ?mO
} C;];4[XR
d5T M_C
~CCRs7V/L
//读取保存的下载信息（文件指针位置） 1p=^I'#
private void read_nPos() MdmS
{ {.qeVE{
try{ 5P-7"g ca
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n*{aN}auJ
int nCount = input.readInt(); ?j9J6=2
nStartPos = new long[nCount]; 0+%{1JkJq
nEndPos = new long[nCount]; q">lP(t
for(int i=0;i<nStartPos.length;i++) *UhYX)J
{ uOUgU$%zqH
nStartPos = input.readLong(); 4<[,"<G~3
nEndPos = input.readLong(); ?-%Q[W
} =+;l>mn?O
input.close(); 8Y?zxmwn]
} N^z4I,GV(
catch(IOException e){e.printStackTrace ();} E j`
catch(Exception e){e.printStackTrace ();} o|O730"2F
} z)p( l!
ui%B|b&&
cu*8,*FU
private void processErrorCode(int nErrorCode) 6RV42r^pf
{ lHQ:LI
System.err.println("Error Code : " + nErrorCode); `,a6su (?
} 67/JsL
no_;^Ou?
&0cfTb)dG
//停止文件下载 .P(k |D&
public void siteStop() p^QZGu-.W
{ BBuI|lr
bStop = true; /}A"F[5
for(int i=0;i<nStartPos.length;i++) n]:Xmi8p
fileSplitterFetch.splitterStop(); |`vwykhezO
7niZ`doBA
>L[n4x\
} kT)[<`p
} V&)Jvx}^
//负责部分文件的抓取 v6=pV4k9
**FileSplitterFetch.java -E{D'X
*/ 1oU/gm$7\q
package NetFox; PJ}d-
8p D$/
`t[b0; 'OH
import java.io.*; m#6RJbEz
import java.net.*; *g7BR`Bt]z
Y\s ge
4P(muOS
public class FileSplitterFetch extends Thread { X.}i9a 6
'kU5
w]L^)_'Th
String sURL; //File URL Xb#!1hA
long nStartPos; //File Snippet Start Position E,IeW {6s
long nEndPos; //File Snippet End Position h;" 9.
int nThreadID; //Thread's ID C\2rSyo
boolean bDownOver = false; //Downing is over x6yYx_
boolean bStop = false; //Stop identical MXQua:&HW
FileAccessI fileAccessI = null; //File Access interface wNc.z*+O"H
xs#g
>,%or cN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #<h//<
{ c_"=G#^9@i
this.sURL = sURL; {BV0Y.O
this.nStartPos = nStart; E;v#'
this.nEndPos = nEnd; m8[XA!,
nThreadID = id; xf2|9Tqt
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7m.#No>^
} yuP1*QJ%
zm>^!j !
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public void run() m&S *S_c
{ suKr//_
while(nStartPos < nEndPos && !bStop) EKu%I~eM
{ [G!#y
hp|.hN(kS]
pW&K=,7|
try{ tzIcR #Z
URL url = new URL(sURL); iYaS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *Wj]e%
httpConnection.setRequestProperty("User-Agent","NetFox"); N!~O~Eo3
String sProperty = "bytes="+nStartPos+"-"; 'ug:ic
httpConnection.setRequestProperty("RANGE",sProperty); deLLqdZa
Utility.log(sProperty); w'uB&z4'
6W\G i>
LX'z7fh
InputStream input = httpConnection.getInputStream(); {,NF'x4$
//logResponseHead(httpConnection); [?>\]
r>ziQq8C&
X!xmto
byte[] b = new byte[1024]; gN@|lHbU
int nRead; k~%j"%OB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wK]p`:3
{ B,S~Idr}
nStartPos += fileAccessI.write(b,0,nRead); bZ0{wpeK=
//if(nThreadID == 1) C))x#P36
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;_X2E~i[
} ;cEoc(<?
;F_pF+&q
=\`iC6xP}
Utility.log("Thread " + nThreadID + " is over!"); /@ww"dmqU
bDownOver = true; rdH3!
//nPos = fileAccessI.write (b,0,nRead); m?O~(6k@C
} J?C#'2/
catch(Exception e){e.printStackTrace ();} n58yR -"
} 3N[Rrxe2
} Ce/l[v
8bJj3vr
%* k`z#b
//打印回应的头信息 zq(4@S-TU
public void logResponseHead(HttpURLConnection con) *^oL$_Y
{ Z% DJ{!Hnh
for(int i=1;;i++) @{>0v"@
{ pC~M5(F_
String header=con.getHeaderFieldKey(i); 5>6:#.f%!e
if(header!=null) :X}n[K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9Iu"DOxX%
Utility.log(header+" : "+con.getHeaderField(header)); .H@b zm
else Cs4ks`Z18
break; ~^TH5n
} R53^3"q~
} Xp+lpVcJ
1/f{1k
lqTc6@:D
public void splitterStop() r2*8.j51
{ NkV81?
bStop = true; A?bqDy
} uH&B=w
t6uYFxE
ds2%i
} ZkJLq[:cM
VqUCcT
B*(BsXQLY
/* M5a&eO
**FileAccess.java xa'^:H $X
*//文件访问(定位，写) *Z$W"JP
package NetFox; yJ/YK
import java.io.*; |}?H$d
+ \]-"
7gcR/HNeF
public class FileAccessI implements Serializable{ _N {4Rs0
%8H$62w]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uPq@6,+
RandomAccessFile oSavedFile; z/]]u.UP
long nPos; $1$0M
M1]}yTCd
R< L =&I
public FileAccessI() throws IOException fK6[ p&
{ "}"/d(
this("",0); C :An
} mW$Oi++'d
:R`e<g~4
5 JlgnxRq
public FileAccessI(String sName,long nPos) throws IOException mlxtey6H3
{ Y&1N*@YP
oSavedFile = new RandomAccessFile(sName,"rw"); '?jsH+j+
this.nPos = nPos; tI@aRF=p]2
oSavedFile.seek(nPos); XzPOqZ`Nv
} F$-fj "jC
t.+)g-X
J'ZC5Xr
public synchronized int write(byte[] b,int nStart,int nLen) #UE}JR3g
{ 'ieTt_1.G
int n = -1; !?>QN'p.b
try{ {cUGksz]}
oSavedFile.write(b,nStart,nLen); oI!"F=?&6
n = nLen; otdRz<C
} z4 <_>)p
catch(IOException e) Oi'y0S~g
{ R7"7 Rx
e.printStackTrace (); Ab]tLz|Z
} 2i0;b|-=
!u'xdV+bf
"F}dZ
return n; z#Fel/L`O
} q 'd]
]ag{sU@#
Q5}XD
} x|yJCs>
EjFn\|VK
",&QO7_
/* F b?^+V]9
**SiteInfoBean.java (3K3)0fy
*/ ">G*hS
package NetFox; t=X=",)f
HE35QH@/`
.^M#BAt2
public class SiteInfoBean { R:+'"dBge
Ge/K.]>i
D+v?zQw
private String sSiteURL; //Site's URL 8R%<~fq r
private String sFilePath; //Saved File's Path SswcO9JCX3
private String sFileName; //Saved File's Name &TY74w*
private int nSplitter; //Count of Splited Downloading File Xy%||\P{)
{Ef.wlZ
ii_kgqT^
public SiteInfoBean() }LCm_av
{//nSplitter的缺省值为5 <T?-A}0uO
//default value of nSplitter is 5 8^^ 1h
this("","","",5); !(7m/R
} kc0MQ TJU
Pn^`_
nShXY6bA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pbEWnx_
{ g<(!>:h
sSiteURL= sURL; 0VcHz$ 6
sFilePath = sPath; "b~C/-W I
sFileName = sName; }A+ncabm
this.nSplitter = nSpiltter; "T_9_6tH
a7c`[
/='0W3+o*L
} U+*l!"O,
ZT@=d$Z&t
|,@D<
public String getSSiteURL() v@|<.
{ ~h_ _Y>
return sSiteURL; }3A~ek#*~
} y~\ujp_5w
U+qyS|i
{ibu0
public void setSSiteURL(String value) vRH^en
{ 'KIT^k0"Ih
sSiteURL = value; C{}PO u
} bJetqF6n
X5YOxMq
eM_;rMCr}
public String getSFilePath() [:.wCG5
{ |,p"<a!+{w
return sFilePath; u{_,S3Aa
} gy%.+!4>v`
Fy"M 4;7
Et!J*{s
public void setSFilePath(String value) &n;*'M
{ {QM rgyQE
sFilePath = value; EP#2it]0]
} )I[f(f%W7
`v!. ,Yr
%Y%r2
public String getSFileName() p~@,zetS
{ h\UKm|BZ
return sFileName; lwq:0Rj@Q
} s[{[pIH
I{OizBom
beBG40
public void setSFileName(String value) aaig1#a@1b
{ u0Wt"d-=
sFileName = value; <HoCt8>U
} zI4rAsysL
o[cOL^Xd1
KR#,6
public int getNSplitter() !nSa4U,$w<
{ V.&F%(L
return nSplitter; /Ne#{*z)hO
} 3T8d?%.l
f-enF)z
84QOW|1
public void setNSplitter(int nCount) a$|U4Eqo
{ k}v`UiGM
nSplitter = nCount; v1 8<~
} %jzTQ+.%]^
} VIz(@
$U*eq[
llP V{
/* KE3`5Y!
**Utility.java /IWAU)A0
*/ YK6LJv}
package NetFox; <4; nq~
04-_ K
FL'}~il
public class Utility { 9$\s v5
g8N"-j&@
ksC_F8Q+
public Utility() aO(PVS|P
{ 2.aCo, Kb;
QcL@3QC
U0_)J1Yp
} %PYO9:n
(U.Go/A#wE
//线程睡眠 ;|WUbc6&g
public static void sleep(int nSecond) OM[MRZEh G
{ D{N8q^Cs9
try{ GK}52,NM
Thread.sleep(nSecond); M!J7Vj?Ps
} + f67y
catch(Exception e) ri{*\LV*@
{ P:'wSE91
e.printStackTrace (); D!~ Y"4<
} btuG%D{a^
} Bib<ySCre
)$:1e)d
//日志 eLSzGbKf
public static void log(String sMsg) Ma|4nLC}
{ t,7%| {
System.err.println(sMsg); ekhv.;N~
} 3:x(2 A
A0Mjk
X(ph$,[
public static void log(int sMsg) tLy:F*1i
{ VO:4wC"7
System.err.println(sMsg); R'v~:wNTNs
} &IQ=M.!r
} uI-T]N:W8x
P+j=]Yg
>}V?GK36
/* tVRN3fJH
**TestMethod.java `3F#k[IR
*/ /Sj~lHh
package NetFox; +]%S}<R
T'5{p
j9NF|
public class TestMethod { b)I-do+
5*$yY-A
O=2|'L'h!
public TestMethod() I_<VGUk
{ ///xx/weblogic60b2_win.exe 6j(/uF4!#
try{ vUpAW[[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g0grfGo2p
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0)WAQt\/
SiteFileFetch fileFetch = new SiteFileFetch(bean); P4[kW}R
fileFetch.start(); `NW/Z/_
} V.*TOU{{xh
catch(Exception e){e.printStackTrace ();} BD C DQ
E@SFK=`
=K`.$R
} \1<'XVS
L0wT:x*
^o3,YH
public static void main(String[] args) |qw0:c=7!
{ L0g+RohW
new TestMethod(); GY]P(NU
} RM|J |R
} tY)L^.*7
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