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)); Z?'|9FM
} jUSr t)o03
for(int i=0;i<nEndPos.length-1;i++) r['C.S6
{ -Ep6.v
nEndPos = nStartPos[i+1]; "1Aus
} : X|7l?{xW
nEndPos[nEndPos.length-1] = nFileLength; 't.F.t
} S Tk#hhx
} j1+Y=@MA
Vp{2Z9]}
Z@/5~p
//启动子线程 =W*`HV-w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nW'x#0-
for(int i=0;i<nStartPos.length;i++) ~GYtU9s5
{ 9W$)W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *S_Iza #&x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }8#Czo jt
nStartPos,nEndPos,i); [`\Qte%UH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vnb#N4vR
fileSplitterFetch.start(); IuW10}"9
} (C@@e'e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0Jh:6F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "QS7?=>*F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P\e%8&_U/
nEndPos = " + nFileLength); (Lnh> '2
// fileSplitterFetch[nPos.length-1].start(); j83 V$ Le
sXu+F2O
9l]IE,u
//等待子线程结束 :TI1tJS~*
//int count = 0; >k|[U[@
//是否结束while循环 ? Q}{&J
boolean breakWhile = false; )K~nZLULY
hgGcUpJy?
A4' aB0^
while(!bStop) ( Iew%U
{ a0.XJR{T"
write_nPos(); f6nltZ
Utility.sleep(500); _wCSL.
breakWhile = true; n}{cs
bAp`lmFI
<lR8MqjM_
for(int i=0;i<nStartPos.length;i++) 2|BE{91
{ d%bL_I)
if(!fileSplitterFetch.bDownOver) qv\yQ&pj
{ t ,$)PV
breakWhile = false; WM26-nR
break; ~\P.gSiz
} Kl?1)u3^4
} ] ?(=rm9u
if(breakWhile) G<'S
break; {Hu0
CR<l"~X
h%%'{^>~
//count++; EcU9Tm`h
//if(count>4) V 6F,X`7
// siteStop(); 0W> ",2|z
} V QI7lJV"
)1/O_N6C
U*cj'`eqC
System.err.println("文件下载结束！"); o=ex{g(3
} h.nzkp5
catch(Exception e){e.printStackTrace ();} b11C3TyQT
} a'BBp6
Sc&_6}K
L6T_&AiL$
//获得文件长度 D$\ EZ
public long getFileSize() bTj,5,8i
{ "TPMSx&Ei
int nFileLength = -1; Z_%>yqDC
try{ o&=m]hKpQl
URL url = new URL(siteInfoBean.getSSiteURL()); y03l_E,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +xMDm_TGLA
httpConnection.setRequestProperty("User-Agent","NetFox"); 945psG@|
i>;G4
gIeo7>u
int responseCode=httpConnection.getResponseCode(); _wIAr
if(responseCode>=400) Ae1},2py
{ N}\i!YUD
processErrorCode(responseCode); 95}"AIi
return -2; //-2 represent access is error ]^!#0(
} ZP1EO Z
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- 0zo>[c/p
String sHeader; 1*Z}M%
T"O!
!)GPI?{^5
for(int i=1;;i++) X:YxsZQ5Y
{ fYwumx`J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gbvBgOp
//Utility.log(in.readLine()); 7\.5G4dr%
sHeader=httpConnection.getHeaderFieldKey(i); "YivjHa7H
if(sHeader!=null) X]N8'Yt
{ x[]n\\a?
if(sHeader.equals("Content-Length")) mWZVO,t$
{ 9rhz#w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W*P/~U=
break; f.!cR3XgV
} 6uDNqq
} \eN}V
else ;(z0r_p<q
break; #6JG#!W
} W)KV"A3C
} ZW2U9
catch(IOException e){e.printStackTrace ();} !aLL|}S
catch(Exception e){e.printStackTrace ();} T3\Q<
^s^X nQhE
g1Aq;Ah/
Utility.log(nFileLength); dD=dPi#
xand%XNv
h9No'!'!
return nFileLength; "/K44(^
} }z}oVc
d>2>mT$U
b?y3m +V`
//保存下载信息（文件指针位置） 9mr99tA
private void write_nPos() leiP/D6s
{ XJ.vj+XXb
try{ Ok9XC <Xu
output = new DataOutputStream(new FileOutputStream(tmpFile)); #5F\zeo@F?
output.writeInt(nStartPos.length); 23zB@aE_?1
for(int i=0;i<nStartPos.length;i++) d&F8nBIM5
{ G>"w$Us
// output.writeLong(nPos); k\A8Z[
output.writeLong(fileSplitterFetch.nStartPos); S_WYU&8
output.writeLong(fileSplitterFetch.nEndPos); 0m!+gZ@
} phd,Jg[
output.close(); 3s" Rv@
} IF<pT)
catch(IOException e){e.printStackTrace ();} u[})|x*N
catch(Exception e){e.printStackTrace ();} bP(xMw<'j
} 8ex{N3
}!x\qpA
(]1n!
//读取保存的下载信息（文件指针位置） qy"#XbBeV
private void read_nPos() M#UW#+*g!
{ a?_N8|k[
try{ 6Gwk*%sb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2/3,%5j_
int nCount = input.readInt(); O$+0 .
nStartPos = new long[nCount]; -r7*C:E
nEndPos = new long[nCount]; %N04k8z
for(int i=0;i<nStartPos.length;i++) o[X'We;
{ x[zt(kC0+
nStartPos = input.readLong(); 2Gd.B/L6
nEndPos = input.readLong(); (]>=y
} vvwNJyU-
input.close(); kZfa8wL]P
} k?ZtRhPu3X
catch(IOException e){e.printStackTrace ();} ]yy10Pk[!
catch(Exception e){e.printStackTrace ();} {1Z8cV
} $hXhq*5|c
iv*`.9TK-
hCS|(8g
private void processErrorCode(int nErrorCode) kr[p4X4
{ ErnjIx:
System.err.println("Error Code : " + nErrorCode); @i U@JE`C
} fMgB!y"Em
5)bf$?d
j51Wod<[
//停止文件下载 LlKvi_z
public void siteStop() e)"]H*
{ o`,|{K$H
bStop = true; O/ Yz6VQ
for(int i=0;i<nStartPos.length;i++) TrD2:N}dI
fileSplitterFetch.splitterStop(); z><uYO$
'RZ=A+%X
++1<A&a
} mCah{~
} B8_)I.
//负责部分文件的抓取 ;r'y/Y'?
**FileSplitterFetch.java lOB*M!8
*/ jd ]$U_U(
package NetFox; =A[:]),v
4 JC*c
jT/}5\
import java.io.*; ML eo3
import java.net.*; c$fi3O
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public class FileSplitterFetch extends Thread { *WTmS2?'h
S\wh *'Y
FVY$A=G
String sURL; //File URL p=13tQS<
long nStartPos; //File Snippet Start Position cl2+,!:
long nEndPos; //File Snippet End Position a* 2*aH7
int nThreadID; //Thread's ID 'OEh'\d+x
boolean bDownOver = false; //Downing is over '?$N.lj$d
boolean bStop = false; //Stop identical MC\rx=cR\
FileAccessI fileAccessI = null; //File Access interface ayGYVYi
4S9hz
\Dn47V{7-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M8Tj;ATr
{ (g(.gN]
this.sURL = sURL; l rRRRR
this.nStartPos = nStart; vH[G#A~4
this.nEndPos = nEnd; I| Vyv
nThreadID = id; 8)KA {gN}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Nj5V" c
} :6h$1 +6
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TK! D=M
public void run() P }BU7`8
{ D6Q6yNE
while(nStartPos < nEndPos && !bStop) |M;tAG$,"y
{ A,H|c="
=P}BAJ
mKTa.
try{ l^~E+F~
URL url = new URL(sURL); 0aWy!d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #.j[iN :+
httpConnection.setRequestProperty("User-Agent","NetFox"); BdMmeM2h
String sProperty = "bytes="+nStartPos+"-"; }piDg(D
httpConnection.setRequestProperty("RANGE",sProperty); #E'aa'P}
Utility.log(sProperty); - WEEnwZ
<i1.W!%
isF jJPe
InputStream input = httpConnection.getInputStream(); 178u4$# b
//logResponseHead(httpConnection); J$+K't5BZ
W]TO%x{
HNMVs]/e
byte[] b = new byte[1024]; 4tGP- L
int nRead; bdxmJ9a:R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VX'cFqrK3
{ S.)+C2g,@
nStartPos += fileAccessI.write(b,0,nRead); )ZHo7X
//if(nThreadID == 1) ^q@6((O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XX9u%BZ~
} ,suC`)R
WVMkLMg8d
r5s$#,O/&Q
Utility.log("Thread " + nThreadID + " is over!"); h%=>iQ%enc
bDownOver = true; )a;ou>u
//nPos = fileAccessI.write (b,0,nRead); j34L*?
} tqMOhR
catch(Exception e){e.printStackTrace ();} =7l'3z8
} _oU}>5
} :enmMB#%
WF&?OHf2
y5!fbmf
//打印回应的头信息 Xlp$xp"
public void logResponseHead(HttpURLConnection con) +<TnE+>j
{ s0/[mAY
for(int i=1;;i++) "'9[c"Iz
{ H}f}Y8J{
String header=con.getHeaderFieldKey(i); ?z/ )Hkw
if(header!=null) ^ALR.N+<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]N#%exBVo
Utility.log(header+" : "+con.getHeaderField(header)); /t$J<bU
else {wS)M
break; pf%B
} i^I U)\
} K:_5#!*^98
C\RJ){dk
=VFPZ
public void splitterStop() KhFw%Z0s<
{ )^q7s&p/
bStop = true; #|ILeby
} !h[xeLlU
OdWZYWj
R32A2Ml
} -w3KBlo
/ZpwJc`e
+yO^,{8SE
/* wx]r{
**FileAccess.java W5c?f,
*//文件访问(定位，写) ,!i!q[YkL9
package NetFox; O3];1ud
import java.io.*; M0$wTmXM
,%!E-gr
{<J(*K*\Jo
public class FileAccessI implements Serializable{ Dqz9NB
A6faRi703
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WNo",Vc
RandomAccessFile oSavedFile; 90rY:!e
long nPos; TTQ(\l4
D&C83^m
1v2pPUH\
public FileAccessI() throws IOException "u=U@1 ^
{ qy$1+>f1
this("",0); e4rhB"qQdn
} M%S.Z4D (0
Ao}J
3l?-H|T
public FileAccessI(String sName,long nPos) throws IOException >M-ZjT>
{ S#g=;hD
oSavedFile = new RandomAccessFile(sName,"rw"); ZBcT@hxm
this.nPos = nPos; GDBxciv
oSavedFile.seek(nPos); j$Unw
} _`LQnRp(
n |Is&fy
=bDy :yY}
public synchronized int write(byte[] b,int nStart,int nLen) sn=_-uoU
{ PY{])z3N
int n = -1; =U)e_q
try{ /ltGSl
oSavedFile.write(b,nStart,nLen); f.X<Mo
n = nLen; W]l&mr
} uFH ]w]X
catch(IOException e) ~o?(O1QY
{ )e6)~3[^
e.printStackTrace (); W2 p&LP
} B^yA+&3HI
}_[Bp
N-cLp}D}WB
return n; 1GA$nFBVC
} .*_uXQ
[<H'JsJl
2zQ62t}
} \cKY{(E
pjVF^gv,*
YKtF)N;m]
/* E Qn4+
**SiteInfoBean.java =FfxHo1k
*/ <{xU.zp'
package NetFox; Aq~}<qkIF+
N# ?}r>W3
c"H59 jE
public class SiteInfoBean { %hM8px4d
XNd%3rm,
qS.TVNZ
private String sSiteURL; //Site's URL /yhGc}h
private String sFilePath; //Saved File's Path Y(D&JKx
private String sFileName; //Saved File's Name }>T$2"pf
private int nSplitter; //Count of Splited Downloading File yR|Beno
IA$)E
[>^xMF]$2
public SiteInfoBean() 0[SJ7k19
{//nSplitter的缺省值为5 (^)" qsB
//default value of nSplitter is 5 rr;p;
this("","","",5); =}h8Cl{H/
} #MwNyZ
md.#n
vy&< O
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,k=1'7d
{ CRKuN
sSiteURL= sURL; KOqp@K$
sFilePath = sPath; uOU?-WtPz
sFileName = sName; 93+p~?
this.nSplitter = nSpiltter; ZM$}Xy\9
P}dhpU
ud}B#{6
} FdZG%N>Z
AR}q<k6E
Gs7#W:e7
public String getSSiteURL() wy)I6`v
{ F9Y/Z5 Ea
return sSiteURL; T+9#&
} D%k`udz<
[`'[)B
e.<y-b?
public void setSSiteURL(String value) N4z(2.
{ 3$E\B=7/U
sSiteURL = value; M1sR+e$"
} `fA|])3T
rElbzL"&<
4PVkKP'/
public String getSFilePath() ecjjCt2S
{ ED>T2.:{
return sFilePath; spVE'"^
} pMfP3G7V
B > sTM
l_`DQ8L`
public void setSFilePath(String value) ^/k`URQ
{ Le*sLuxk<
sFilePath = value; T9,T'y>BD
} G{8>
/1Q i9uit
HRPNZ!B
public String getSFileName() [nBdq"K
{ N=`xoF
return sFileName; D02_ Jrg
} W%)uKQha
@H?_x/qBT
:())%Xu3
public void setSFileName(String value) x-Cy,d:YX
{ 2?)bpp$WZ
sFileName = value; XehpW}2\
} w=r3QKm#K
}.uB6&!:
ns{BU->f
public int getNSplitter() mM&*_#( 6
{ ~;pv&s5}
return nSplitter; -}h+hS50F
} bg8<}~zg
x@@U&.1_A
*i}Nb*Z3
public void setNSplitter(int nCount) Mk*&CNo3
{ #..-!>lY
nSplitter = nCount; d]v4`nc
} ZW]Q|vPh4U
} I^5T9}>Q
LOD'iiH6
f-V8/
/* ; U)a)l'y
**Utility.java i&r56m<
*/ =s2dD3Fr|
package NetFox; y5XHJUTu
Dn6k,nVh
&*I\~;1
public class Utility { o4)^U t+
x<0-'EF/S
yAu-BObD
public Utility() 'wo[iNy[
{ q/o|uAq
n\nC.|_G@
e7{n=M
} AC=/BU3<yc
6,"fH{Bd
//线程睡眠 Y* #'Gh,
public static void sleep(int nSecond) VQm)32'
{ iY=M67V
try{ OHqc,@a;+
Thread.sleep(nSecond); wAr (5nEbx
} RLypWjMx$
catch(Exception e) [<)/ c>Y
{ avR4#bfc
e.printStackTrace (); ;&2J9
} &%~2Wm
} apxZ}
{emO&#=@CP
//日志 xw*T?!r=V
public static void log(String sMsg) 5!ll #/ {`
{ {x $H#<Y
System.err.println(sMsg); /znW$yh o
} kL.JrbM"
JM5w`=
SxMrX C*
public static void log(int sMsg) 0`=#1u8
{ "5mdq-h(
System.err.println(sMsg); $_-f}E
} \(t.|
} n*6b*fl
N|c;Qzl
QN_Zd@K*A
/* :CO>g=`
**TestMethod.java 6(4FC?Y7
*/ nB?$W4
package NetFox; w/r wE
.__X-+^
.jRp.U
public class TestMethod { UY*3b<F}
0c4H2RW
1 dT1DcZ
public TestMethod() G>{Bij44
{ ///xx/weblogic60b2_win.exe @Otom'O
try{ A-\OB Nh
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V`Z-m-V~1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _}.BZ[i
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^)Xl7d|m+
fileFetch.start(); <Q'J=;vV
} 9L;fT5Tp7
catch(Exception e){e.printStackTrace ();} {-IH?!&v
G2Eke;
[mKPOg-t
} <zE,T@c
lz.ta!6
_p/ _t76s
public static void main(String[] args) !Mp.jE
{ X4LU/f<f
new TestMethod(); bD[W`yW0
} I/D(gY06<
} 5y;texsj[
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