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)); Xew1LPI
} * Y%<b86U
for(int i=0;i<nEndPos.length-1;i++) XYK1-m}2
{ A'~%_}
nEndPos = nStartPos[i+1]; MR?*GI's
} [B"dH-r7
nEndPos[nEndPos.length-1] = nFileLength; Mf;|z0UX
} Uaus>Frx.T
} =YXe1$ $
U=&^H!LVY
4[LLnF--
//启动子线程 ElEv(>G*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]M+VSU
for(int i=0;i<nStartPos.length;i++) Z92iil;t
{ ~|r'2V*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O ':0V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $TD~k;
nStartPos,nEndPos,i); ~$&:NB1~q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $KwI}>E4
fileSplitterFetch.start(); w PG1P'w;
} I9[1U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kb"_6,[Ms
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xb+RRTgj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qLQ <1>u
nEndPos = " + nFileLength); kvW|=
// fileSplitterFetch[nPos.length-1].start(); X6LhM
q3AJwELXw
n*vTVt)dJ
//等待子线程结束 nOAJ9
//int count = 0; fr}1_0DDz
//是否结束while循环 ,?xLT2>J_
boolean breakWhile = false; )h>\05|T
,]PyDq6
i}/e}s<-6
while(!bStop) -y&v9OC2-
{ E ;BPN
write_nPos(); b)on A|
Utility.sleep(500); _KB{J7bs<a
breakWhile = true; V>b2b5QAH,
}J ei$0x
'%zN
for(int i=0;i<nStartPos.length;i++) W>5vRwx00
{ ,hpH!J'5f/
if(!fileSplitterFetch.bDownOver) e2]4a3
{ *#&k+{a^2
breakWhile = false; |^7f\.oF
break; 8sN#e(@
} V=j-Um;
} DS#cm3
if(breakWhile) w/b>awI
break; =jg#fdM -
mR{CVU
Y7<zm}=(/
//count++; eu#,WwlG
//if(count>4) Zg -]sp]
// siteStop(); &8[ZN$Xe"
} CS/Mpmsp
!c3```*
:a_BD
System.err.println("文件下载结束！"); _j:UGMTi(U
} B.89_!/:p
catch(Exception e){e.printStackTrace ();} V]I:2k5
} ?PBa'g
QGs1zfh*
k:b/Gq`
//获得文件长度 S~KS9E~\
public long getFileSize() aq3~!T;W
{ 3lo;^KX !
int nFileLength = -1; Z[",$Lt
try{ KcC!N{
URL url = new URL(siteInfoBean.getSSiteURL()); %'Zc2h&z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,N53Iic
httpConnection.setRequestProperty("User-Agent","NetFox"); Iz DG&c
?Bo?JMV
OFc\fW#
int responseCode=httpConnection.getResponseCode(); x^A7'ad0
if(responseCode>=400) ""co6qo#>
{ 1HMUHZT
processErrorCode(responseCode); T4mv%zzS
return -2; //-2 represent access is error q@(1Yivk
} zVSx$6eiU
7;&(}
y|$R`P
String sHeader; ev9;Ld
"\e:h| .G
$}t=RW
for(int i=1;;i++) Pm4e8b
{ 3sH\1)Zz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g>so R&*
//Utility.log(in.readLine()); Vy__b=ti?
sHeader=httpConnection.getHeaderFieldKey(i); !; IJ
if(sHeader!=null) 9A~>`.y
{ {fZb@7?GF
if(sHeader.equals("Content-Length")) geksjVwPH
{ '"y}#h__T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Yc^%zxub
break; ?hnx/z+uT
} !O|ql6^;
} 3gAR4
else xq}-m!nX
break; \[yr=X
} pz{'1\_+9
} )zU:
catch(IOException e){e.printStackTrace ();} ]*qU+&
catch(Exception e){e.printStackTrace ();} 8".2)W4*
LheFQ A
C,/O
Utility.log(nFileLength); ?WQNIX4
$B\ H
1BJ<m5/1%
return nFileLength; 6B0#4Qrv
} Gav"C{G
F/>*Ifs
nZfs=@w:y
//保存下载信息（文件指针位置） U@'F%nHw
private void write_nPos() yGxv?%%2
{ (&jW}1D
try{ kY"KD22a
output = new DataOutputStream(new FileOutputStream(tmpFile)); F$Hx`hoy
output.writeInt(nStartPos.length); 69-:]7.g
for(int i=0;i<nStartPos.length;i++) u:@U $:sZ
{ Y25^]ON*\^
// output.writeLong(nPos); #02Kdo&Vy
output.writeLong(fileSplitterFetch.nStartPos); ?]c+j1i
output.writeLong(fileSplitterFetch.nEndPos); 8V9[a*9
} \q "N/$5{f
output.close(); 7Y1GUIRa3
} r`jWp\z
catch(IOException e){e.printStackTrace ();} %Tv^GP{}
catch(Exception e){e.printStackTrace ();} gY(1,+0-
} fiVHRSX60
jfD1
WK0C
//读取保存的下载信息（文件指针位置） 4*TmlY
private void read_nPos() qTT,U9]:
{ Tk*w3c"$
try{ WF2NG;f=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rAb&I"\ZY
int nCount = input.readInt(); MuwQZ]u
nStartPos = new long[nCount]; Ha%F"V*
nEndPos = new long[nCount]; d H? ScXM=
for(int i=0;i<nStartPos.length;i++) .Pe9_ZH$W
{ ZtK\HDdp
nStartPos = input.readLong(); PY`L$e
nEndPos = input.readLong(); 1svi8wh
} 9xFO]Y"
input.close(); \=;uu_v$
} Ye5jB2Z
catch(IOException e){e.printStackTrace ();} wG1l+^p
catch(Exception e){e.printStackTrace ();} ;#1Iiuh
} WkP +r9rT
tu0aD%C
\}5p0.=
private void processErrorCode(int nErrorCode) d,0 }VaY=D
{ a^t?vv
System.err.println("Error Code : " + nErrorCode); H6K`\8/SeN
} )}MHx`KT2
WA6!+Gy
?<U{{C
//停止文件下载 ,lt8O.h-l
public void siteStop() FY'ty@|_s
{ cK@jmGj+
bStop = true; "B{ECM;
for(int i=0;i<nStartPos.length;i++) 0:=ZkEEeU
fileSplitterFetch.splitterStop(); l>6@:nq|R
x[Im%k
o31Nmy Ni
} \K iwUz
} H={&3poBz
//负责部分文件的抓取 ;apzAF
**FileSplitterFetch.java ?kTWpXx"=
*/ $s\UL}Gc
package NetFox; El- ? %
e5?PkFV^a1
a.@qGsIH
import java.io.*; :7g=b%;
import java.net.*; T6#CK
WC,+Cn e
`.%JjsD<
public class FileSplitterFetch extends Thread { !ABiy6d
rJJ[X4$
vUA0FoOp
String sURL; //File URL aG+j9Q_
long nStartPos; //File Snippet Start Position 5D Y\:AF
long nEndPos; //File Snippet End Position W_`A"WdT.
int nThreadID; //Thread's ID HYK!}&
boolean bDownOver = false; //Downing is over ]Mi.f3QlO6
boolean bStop = false; //Stop identical h3* x[W
FileAccessI fileAccessI = null; //File Access interface \4d.sy0&>-
0d^Z uTN
({^9<Us
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e>}}:Ud
{ \HZ9S=
this.sURL = sURL; "TcW4U9
this.nStartPos = nStart; lrWQOYf2
this.nEndPos = nEnd; +7V{ABfGl
nThreadID = id; zYY$D.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *sw7niw
} O#a6+W"U
CZ<~3bEF
&HW1mNF9
public void run() X2|Y
{ N8r*dadDd
while(nStartPos < nEndPos && !bStop) en F:>H4
{ (1R?s>3o
L!Cz'm"Nl
laKuOx}
try{ Pmg)v!"
URL url = new URL(sURL); .@q-B+Eg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?, r~=
httpConnection.setRequestProperty("User-Agent","NetFox"); FR[ B v
String sProperty = "bytes="+nStartPos+"-"; uX/$CM
httpConnection.setRequestProperty("RANGE",sProperty); ;%C'FV e]
Utility.log(sProperty); e({9]
@f+8%I3D
oR1^/e
InputStream input = httpConnection.getInputStream(); N2'qpxOLI
//logResponseHead(httpConnection); Z?P~z07
nl aM
lv&mp0V+
byte[] b = new byte[1024]; +=q)
int nRead; YgUH'P-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *l+OlQI0+
{ ?>c=}I#Ui-
nStartPos += fileAccessI.write(b,0,nRead); >LC<O.
//if(nThreadID == 1) "9EE1];NT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2&PPz}Sw
} iD38\XNMV
mW2,1}Jv
qBV x6MI
Utility.log("Thread " + nThreadID + " is over!"); 3.d"rl
bDownOver = true; Y9=K]GB
//nPos = fileAccessI.write (b,0,nRead); )4>2IQ
} 57a2^
catch(Exception e){e.printStackTrace ();} 'ly?P8h
} "gtHTqheH
} [H<bh%
O,bkQY$v
.nu @ o40
//打印回应的头信息 T<3BT
public void logResponseHead(HttpURLConnection con) fKC3-zm
{ =<r8fXWZ
for(int i=1;;i++) g]c[O*NTL
{ |Xi%
String header=con.getHeaderFieldKey(i); u's`*T@.
if(header!=null) 3A:q7#m
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n<sd!xmqFx
Utility.log(header+" : "+con.getHeaderField(header)); ,;?S\V
else =gfI!w
break; \<Sv3xy&O
} p.I.iAk%G^
} eI.2`)>
]M/9#mD9~
vb 1@yQ
public void splitterStop() !Cgx.
{ -K,-h[o
bStop = true; CQ`=V2:"ON
} ah @uUHB
SG}V[Glk
5uq3\a
} Uz cx6sw
%75xr9yOP
H>9CW<8
/* p4IZ
**FileAccess.java MuoF FvAA
*//文件访问(定位，写) C%*k.$#r!
package NetFox; [7(-T?_
import java.io.*; xtPLR/Z
L %ip>
m)V/L]4
public class FileAccessI implements Serializable{ Hf'G8vW
UnVm1ZWZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G}5#l
RandomAccessFile oSavedFile; 1/p*tZP8i
long nPos; ^c~)/F/cF
^pn(=4
1qV@qz
public FileAccessI() throws IOException e8YMX&0%
{ ^pM+A6 XY
this("",0); h:lt<y
} ]Jh+'RK\#
1ygpp0IGJ
1c JF/"v
public FileAccessI(String sName,long nPos) throws IOException PoEqurH0
{ r=yK,d/1
oSavedFile = new RandomAccessFile(sName,"rw"); AiD[SR
this.nPos = nPos; Fnk_\d6Ma
oSavedFile.seek(nPos); -{^}"N
} `eu9dLzH
.NtbL./=|
,=?{("+
public synchronized int write(byte[] b,int nStart,int nLen) 4f(Kt,0
{ 6}FO[
int n = -1; %OgS^_tu
try{ Sq:0w
oSavedFile.write(b,nStart,nLen); $}")1|U,X
n = nLen; Ra*e5
} kB5.(O
catch(IOException e) NrP0Ep%V
{ p ?wI9GY
e.printStackTrace (); '`1CBU$
} (98Nzgxgx}
:eo
CK, 6ytB
return n; {'16:dTJ
} '!f5?O+E
R |KD&!~Z
rJ KZ)N{
} 5NJ4
hzk6rYg1
nQ|r"|g
/* r\nx=
**SiteInfoBean.java ie-vqLc
*/ zE;bBwy&
package NetFox; Be+0NXLVy
%e*@CbO$
5SkW-+$
public class SiteInfoBean { 5>AX*]c
T{wuj[Q#:
u&wiGwF[
private String sSiteURL; //Site's URL m7T)m0
private String sFilePath; //Saved File's Path h*ZC*eV>
private String sFileName; //Saved File's Name #07gd#j4
private int nSplitter; //Count of Splited Downloading File :!zl^J;
&@ JvnO:
(knp#
public SiteInfoBean() 9'hv%A:\3
{//nSplitter的缺省值为5 };'\~g,1
//default value of nSplitter is 5 nC{%quwh{
this("","","",5); Zw wqSyuGf
} ^&g=u5 d0
wcDRH)AW.
!bV5Sr^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]({~,8s
{ 43V}#DA@
sSiteURL= sURL; VY)s+Bx
sFilePath = sPath; 2Pc%fuC
sFileName = sName; vFEQ7qI
this.nSplitter = nSpiltter; / g 2b
IHRGw
kA7mLrON
} IKie1!ZU{"
J*9$;
bTQNb!&
public String getSSiteURL() Ytgj|@jsp
{ aZbw]0q@o
return sSiteURL; l3 DYg
} 1#1 riM -
u+{a8=
i1RiGS
public void setSSiteURL(String value) }jill+]
{ A=Ss6-Je
sSiteURL = value; %c[V
} #pcP!
:T9<der,
%u;~kP|S%
public String getSFilePath() z2Z^~,i
{ GKcv<G208
return sFilePath; a'\o7_
} Mfv1Os:ST
41SGWAd#:
? R>h `
public void setSFilePath(String value) fU!<HDh
{ 9uWY@zu
sFilePath = value; /> 4"~q)
} Zdn~`Q{
"1,pHR-+R
0T46sm r
public String getSFileName() 'fPdpnJ<
{ r[K5w
return sFileName; ~H!S,"n^,P
} "+unS)M;Y
;t+ub8
jbR0%X2
public void setSFileName(String value) E\C9|1)
{ K(q-?n`<
sFileName = value; [k-+AA>:
} B2ec@]uD`
36am-G
MeUaTJFEB
public int getNSplitter() |<O9Sb_
{ t:fFU1x
return nSplitter; Q?X>E3=U
} ]KJj6xn
R i^[i}
tr7<]Hm:
public void setNSplitter(int nCount) i E CrI3s
{ ~/*MY
nSplitter = nCount; g(4xC7xK6
} o;?/HE%,[
} 85GKymz$P
MQ"xOcD*F
+5XpzZ{#Wa
/* /B}lO0]:
**Utility.java T*KMksjxm`
*/ 7k8pZ
package NetFox; JY6 Qp
XU"~h64]
{GJ@psG*
public class Utility { k?'B*L_Mzv
:kGU,>BN
nR`ov1RH
public Utility() ;amXY@RmH
{ xNbPsoK
yiO.z
F8apH{&t
} 50={%R
|DsnNk0c
//线程睡眠 F;]%V%F.X
public static void sleep(int nSecond) \eFR(gO+
{ #t+d iR
try{ YIjTL!bA"
Thread.sleep(nSecond); nvPwngEQm
} q`r**N+zn
catch(Exception e) l'eyq}&
{ 6R^^.tCs
e.printStackTrace (); 8-O)Xx}cU
} LGtIm7
} V5rST +
KY~-;0x
//日志 BT(CM,bp
public static void log(String sMsg) G["c\Xux
{ w`5xrqt@
System.err.println(sMsg); Ih"XV
} cCxBzkH6
p3^m9J
ynrT a..
public static void log(int sMsg) ^U!0-y
{ 4F{70"a
System.err.println(sMsg); GP#aya
} 8e(\%bX
} L+q/){Dd(
>:b Q
@/31IOIV]`
/* OE-gC2&Bm
**TestMethod.java -(=eM3o-9m
*/ 3p'I5,}
package NetFox; Cid ;z
GmP@;[H"
8Q'0h m?
public class TestMethod { {yExQbN
%QP0
2=^m9%
public TestMethod() n<u $=H
{ ///xx/weblogic60b2_win.exe X)% A6M
try{ qXwPDq/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >j QWn@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J7g8D{4
SiteFileFetch fileFetch = new SiteFileFetch(bean); \QCJ4}\CS
fileFetch.start(); Dbz3;t
} ^t#&@-'(d
catch(Exception e){e.printStackTrace ();} aSnFKB
eYvWZJa4
55fC~J<
} ^=-y%kp"
Sb82}$sO
{.INnFGP@)
public static void main(String[] args) nX`u[ks
{ ]@u6HH~^
new TestMethod(); RtM8yar+sn
} EU+S^SyZi
} =aTv! 8</
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