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)); o{,(`o.1O
} E 4(muhY
for(int i=0;i<nEndPos.length-1;i++) {_D'\i(Y_
{ BbhdGFG1
nEndPos = nStartPos[i+1]; 6iS+3+
} gU$3Y#R
nEndPos[nEndPos.length-1] = nFileLength; Z.19v>-c
} SaScP
} rV{e[fGd
N1+]3kt ~
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//启动子线程 je0 ?iovY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Tdp$laPO'
for(int i=0;i<nStartPos.length;i++) Q 7?4GxMj
{ 0;`PHNBq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fsdn2{g8U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !T1i_
nStartPos,nEndPos,i); $:P~21,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cA^7}}?e
fileSplitterFetch.start(); XBBRB<l)
} TMs\#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [r~lO@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4iPg_+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UY^f|f&
nEndPos = " + nFileLength); qTex\qP
// fileSplitterFetch[nPos.length-1].start(); mQ)l`wGh
MYm6C;o$
jP]'gQ!-w
//等待子线程结束 8BdeqgU/_
//int count = 0; kF7Al]IgT
//是否结束while循环 Yf9L~K
boolean breakWhile = false; W12K93tO
>.A:6
cZ,_O~
while(!bStop) l#:Q V:
{ r#}%sof
write_nPos(); mcracj[B
Utility.sleep(500); Q?q m~wD
breakWhile = true; m]vr|:{6/
Sy~Mh]{E
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for(int i=0;i<nStartPos.length;i++) EZFWxR/
{ \/GY0s
if(!fileSplitterFetch.bDownOver) ld6@&34
{ W6>uLMUa
breakWhile = false; l\GNd6)H
break; l{yPO@ut`F
} [J#(k`@
} p*,mwKN:
if(breakWhile) W>49,A,q
break; XsCbA8Qv
:zoX Xo
'LI)6;Yc
//count++; Plv+mb
//if(count>4) w9BH>56/"
// siteStop(); _69\#YvCG
} ivk|-C'\
mUw,q;{
Li^V?
System.err.println("文件下载结束！"); XDQ1gg`
} YKk%;U*
catch(Exception e){e.printStackTrace ();} t~M_NEPxV
} $P~a
NI)nf;C
i=UJ*c
//获得文件长度 }mK_d9dx
public long getFileSize() + u+fEg/A
{ x(~l[hT
int nFileLength = -1; G[ea@u$?
try{ [8n4lE[)"
URL url = new URL(siteInfoBean.getSSiteURL()); UYUdIIoL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |@F<ajlV
httpConnection.setRequestProperty("User-Agent","NetFox"); Y_B(R
5 Da(DA
[d}1Cq=_
int responseCode=httpConnection.getResponseCode(); \~>#<@h
if(responseCode>=400) UK/k?0
{ ;'kH<Iq
processErrorCode(responseCode); d0d2QRX
return -2; //-2 represent access is error YVi]f2F%
} AnQRSB (
#e[5O|V~
i\b2P2 `B
String sHeader; MaM7u:kD#
a6C~!{'nW
BVDo5^&W
for(int i=1;;i++) wim}}^H
{ 8?!Vr1x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c`cPGEv
//Utility.log(in.readLine()); P? n`n!qZ
sHeader=httpConnection.getHeaderFieldKey(i); $hapSrS
if(sHeader!=null) l0f6Lxfz
{ $I%]jAh6
if(sHeader.equals("Content-Length")) .*{LPfD|
{ H{If\B%1t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3ly|y{M",
break; 191)JWfa
} .'M]cN~
} a>6p])Wh
else !xSGZD=AD
break; n&^Rs)%v
} MG|NH0k
} Bb6_['y
catch(IOException e){e.printStackTrace ();} 2_p/1Rs
catch(Exception e){e.printStackTrace ();} "#%T*c{Tf0
D KOdqTW
}N NyUwFa
Utility.log(nFileLength); tQ"PCm
F/h)azcn
Z q)A"'Y
return nFileLength; Bs*s8}6
} n$>H}#q
O\?ei+(H7
SrxX-Hir
//保存下载信息（文件指针位置） sE% n=Ww
private void write_nPos() _kfApO)O
{ q%l<Hw6{z
try{ a"EXR-+8
output = new DataOutputStream(new FileOutputStream(tmpFile)); MWB?V?qPSC
output.writeInt(nStartPos.length); {v(3[7
for(int i=0;i<nStartPos.length;i++) %rkUy?=vu
{ ouujd~b+
// output.writeLong(nPos); H3JWf MlW
output.writeLong(fileSplitterFetch.nStartPos); RAvV[QkT
output.writeLong(fileSplitterFetch.nEndPos); f-PDgs
} 6xwC1V?:0t
output.close(); }0I! n@
} NW$Z}?I
catch(IOException e){e.printStackTrace ();} &Ef'5
catch(Exception e){e.printStackTrace ();} U<t Qj`
} 0>vm&W<?)
ke0Vy(3t{h
zK}.Bhj#
//读取保存的下载信息（文件指针位置） JP#m}W
private void read_nPos() -<.>jX
{ x~ I cSt
try{ ?AR6+`0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4&tY5m>
int nCount = input.readInt(); )<+Z,6
nStartPos = new long[nCount]; K:y>wyzl
nEndPos = new long[nCount]; )s M}BY
for(int i=0;i<nStartPos.length;i++) xf|=n
{ 3oj30L.
nStartPos = input.readLong(); HG3jmI+u>
nEndPos = input.readLong(); >%{h_5
} sf%=q$z
input.close(); K-K+%U
} %k"-rmW
catch(IOException e){e.printStackTrace ();} 6_XTeu
catch(Exception e){e.printStackTrace ();} QJxcH$
} ~*&_zPTN
nRvV+F0#
Upf1*$p
private void processErrorCode(int nErrorCode) 3N?uY2
{ #+XKfumLk
System.err.println("Error Code : " + nErrorCode); f"/NY6
} w$1.h'2
8YCtU9D
7:]I@Gc'
//停止文件下载 u4%-e)$X
public void siteStop() -)w/nq
{ avdi9!J2
bStop = true; rLp0VKPe
for(int i=0;i<nStartPos.length;i++) B4|3@X0(
fileSplitterFetch.splitterStop(); - iU7'
nfd^'}$]
Hc}(+wQN%
} #;+GNF}0mG
} Bdf3@sbM]
//负责部分文件的抓取 NVP~`sxiZ
**FileSplitterFetch.java 07n=H~yU
*/ W Qe>1
package NetFox; =VDN9-/.
pDW .Pav
VF;%Z
import java.io.*; =>&d[G[m!
import java.net.*; L,n'G%
p=p,sJ/@
th !Gc
public class FileSplitterFetch extends Thread { RE*;nSVFt
wqJH
VsFRG;:\U
String sURL; //File URL 5'6Oan7dL:
long nStartPos; //File Snippet Start Position +YXyfTa
long nEndPos; //File Snippet End Position 2: fSn&*/>
int nThreadID; //Thread's ID (T,ST3{*k
boolean bDownOver = false; //Downing is over IU&n!5d$)|
boolean bStop = false; //Stop identical (.Sj"6+
FileAccessI fileAccessI = null; //File Access interface .7{,u1N'
+hi!=^b]
hCM+=]z"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException J-b Z`)[Q
{ OF!(BJL
this.sURL = sURL; }{HlY?S
this.nStartPos = nStart; e_7a9:2e
this.nEndPos = nEnd; Ymx/N+Jl
nThreadID = id; *&!&Y*Jzg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T2GJoJ!
} U",kAQY
{o AJL
CPAizS
public void run() t '* L,
{ ^k/@y@%
while(nStartPos < nEndPos && !bStop) dCN4aY[d
{ kowBB0
G8H=xr#
</Ja@%
try{ |G }qY5_
URL url = new URL(sURL); 5Q =o.wf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |}=xA%)
httpConnection.setRequestProperty("User-Agent","NetFox"); bt"*@NJ$
String sProperty = "bytes="+nStartPos+"-"; \K55|3~R
httpConnection.setRequestProperty("RANGE",sProperty); Xbe=_9l&p
Utility.log(sProperty); Sw%^&*J
/GqW1tcO
+uLl3(ml
InputStream input = httpConnection.getInputStream(); p{NVJ^!+
//logResponseHead(httpConnection); sBt,y_LW
-6@#Nq_iWU
\'x.DVp
byte[] b = new byte[1024]; ;X*I,g.+H
int nRead; :.J Ad$>P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Gg8F>y<[R
{ l*^c?lp)
nStartPos += fileAccessI.write(b,0,nRead); u8 Q`la
//if(nThreadID == 1) M:rE^El
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &( aw
} .7_<0&kW
3vepJ)D (
SN'j?-
Utility.log("Thread " + nThreadID + " is over!"); D.su^m_1
bDownOver = true; R0HzNk
//nPos = fileAccessI.write (b,0,nRead); )T&ZiHIJ3
} gd#+N]C_
catch(Exception e){e.printStackTrace ();} @T)kqT
} dv1Y2[
} bdbTK8-
jI[Y< (F ;
=*>ri
//打印回应的头信息 )G a5c
public void logResponseHead(HttpURLConnection con) 5bBY[qp
{ epXvk &
for(int i=1;;i++) 5L!EqB>m;
{ %=e^MN1
String header=con.getHeaderFieldKey(i); O4t0 VL$
if(header!=null) 7wKT:~~oS3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VN]70LFz*i
Utility.log(header+" : "+con.getHeaderField(header)); > &tmdE
else 8Mg wXH
break; SI\ O>a9{
} <5BNcl\ZL
} >>%m,F[
'A2^K5`3
J;wDvt]]1
public void splitterStop() M-7^\wXTA
{ !-B$WAV
bStop = true; B:oE&Ahh{
} r^zra|]
;iq H:wO
{0?^$R8j
} \3q Z0
a!guZUg6
jJbS{1z
/* &Zy%Zz
**FileAccess.java rJtpTV@.
*//文件访问(定位，写) s`#g<_{X
package NetFox; jEu-CU#:
import java.io.*; o&-D[|E|
pm` f?Py
T]oVNy
public class FileAccessI implements Serializable{ ;T hn C>U
B5v5D[ o5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @5}(Y( @
RandomAccessFile oSavedFile; rUn1*KWbE
long nPos; :yxP3e%rp
5LaF'>1yY
OJ?U."Lxm$
public FileAccessI() throws IOException N.'-9hv
{ LiyR,e
this("",0); ?LSwJ @#
} jEMnre3/
;suY
q8SHFKE
public FileAccessI(String sName,long nPos) throws IOException \$+#7( K
{ _*wkTI+j
oSavedFile = new RandomAccessFile(sName,"rw"); /`s{!t#Y
this.nPos = nPos; b]5/IT)@O
oSavedFile.seek(nPos); Mh"iyDGA
} <H,E1kGw9
bUU\bc
k|4}Do%;
public synchronized int write(byte[] b,int nStart,int nLen) }y>/#]X
{ yU|=)p5
int n = -1; fL(_V/p^
try{ Q3<ctd\]Y
oSavedFile.write(b,nStart,nLen); l3N '@GO
n = nLen; 'r'+$D7
} Rt.2]eZEJ
catch(IOException e) d~qZ;uw
{ \)M EM=U
e.printStackTrace (); 6DVHJ+WTV
} ?G>E[!8ev
;q?WU>c{?
F]GX;<`
return n; Ve\.7s
} BN1,R] *;
+?'a2pUS
dnzZ\t>U
} TUN6`/"
O[+\` 63F=
R+# g_"1@p
/* +!/pzoWpE
**SiteInfoBean.java BD2Gv)?g
*/ d1}cXSQ1T
package NetFox; @Zzg^1Ilpu
"Wg5eML0
-&h<t/U
public class SiteInfoBean { /lLG|aAe
&SMM<^P.
$Zn>W@\
private String sSiteURL; //Site's URL nmw#4yHYy:
private String sFilePath; //Saved File's Path 7V%b!R}
private String sFileName; //Saved File's Name <YAs0
private int nSplitter; //Count of Splited Downloading File a\m0X@Q
^!6T,7B B
)O,+'w?
public SiteInfoBean() yRWZ/,9x
{//nSplitter的缺省值为5 1}q(Pn2
//default value of nSplitter is 5 iw^"?:'%
this("","","",5); E?h'OR@_ L
} 5Z>+NKQ
ZMEYF!jN
,8.zbr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ({<qs}H"
{ | MXRNA~
sSiteURL= sURL; UYH&x:WEd
sFilePath = sPath; o4H'
sFileName = sName; ._p^0UxT
this.nSplitter = nSpiltter; 9gFfbvd
5Z_aN|Xn
_N"c,P0
} Q"k #eEA
_|>bOI
i\zN1T_
public String getSSiteURL() MZt&HbD-
{ a?X#G/)
return sSiteURL; :0% $u>;O:
} vv1W<X0e<
@4wN-T+1
$aY:Z_s
public void setSSiteURL(String value) DfZ)gqp/Av
{ \|7Y"WEQ
sSiteURL = value; pnGDM)H7
} Y'?{yx{
K7},X01^
ub-vtRpm
public String getSFilePath() *#Iqz9X.Y3
{ ug?#Oa
return sFilePath; ^,#MfF6
} "|GX%>/
m88[(l
pAH9
public void setSFilePath(String value) @rlL'|&X*
{ \GCT3$
sFilePath = value; 72sBx3 ;
} t+aE*Q
X?SLYm@v
J5zu}U?
public String getSFileName() "v+%F
{ p><DA fB
return sFileName; `l-R?C?*!
} xeSv+I-b
q;<Q-jr&O
~2}^ -,
public void setSFileName(String value) 2(>=@q.1H
{ eB5<N?;s
sFileName = value; tVHQ$jJY%
} zfA"xD
IWnyqt(k
+||[H)qym
public int getNSplitter() J Sms \
{ 2KSt4oa
return nSplitter; s/OXZ<C|
} u`wT_?%w
C44*qiG.
z1LY|8$G
public void setNSplitter(int nCount) 7J$Yd976
{ '?b.t2
nSplitter = nCount; 8zH/a
} UpqDGd7M
} }\d3
$F~hL?"?
Ffr6P }I
/* aR0v qRF
**Utility.java )}SiM{g
*/ 3L%g2`
package NetFox; Eq'oy~.oV
!Nno@SP@
hP=z<&zb/
public class Utility { (N$$N:ac[t
{-,^3PI\
-0:B2B
public Utility() hionR)R4
{ Xj;5i Vq
Ge4tc
+( V+XT
} R,ddH[3
q pFzK
//线程睡眠 P8;f^3V(+/
public static void sleep(int nSecond) Mta;6<
{ {bPcr hB
try{ &Qq4xn+J
Thread.sleep(nSecond); dIDs~
} T(6B,
catch(Exception e) 8Zvh"Z?
{ t+BLO<
e.printStackTrace (); -g)*v<Fb5
} IP+1 :M
} x_|:3I
0 ;ov^]
//日志 ?u8vK<2h
public static void log(String sMsg) 1Qgd^o:d
{ 0-w^y<\
System.err.println(sMsg); ^Sz?c_<2P
} d 3}'J
od~`q4p1(-
js8\"
public static void log(int sMsg) 7<c&)No;
{ S~4HFNe^&
System.err.println(sMsg); i*%2 e)
} <jRs/?1R
} Gq r(.
]qk/V:H:
44kb
/* P1mPC
**TestMethod.java _G5MQ%z
*/ yy-\$<j
package NetFox; zVs|go>F
aXefi'!6
QZ54Osdl
public class TestMethod { yi/jZX
yD!V;?EnK
J#y?^Qm$)<
public TestMethod() ps6c>AN`A&
{ ///xx/weblogic60b2_win.exe "Z6:d"S`
try{ `?L-{VtM3*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $MG. I[h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `;R|SyrX
SiteFileFetch fileFetch = new SiteFileFetch(bean); id.W"5+
fileFetch.start(); y3!=0uPf
} D?_#6i;DJ
catch(Exception e){e.printStackTrace ();} g$*VA} s
zorTZ #5
/< CjBW:
} q>q@ztt
xbA% 'p
o s HE4x
public static void main(String[] args) {G%!M+n<
{ 4GRmo"S
new TestMethod(); ~f2zMTI|
} gaJIc^O
} M('cG
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