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)); $3d}"D
} BYM3jXWi0v
for(int i=0;i<nEndPos.length-1;i++) id?#TqD
{ &6j<ca
nEndPos = nStartPos[i+1]; ^#):c`
} >|o_wO
nEndPos[nEndPos.length-1] = nFileLength; 2`a q**}
} 45@]:2j
} =9G;PVk|
3p*-tBOO
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//启动子线程 s-W[.r|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f{lZKfrp
for(int i=0;i<nStartPos.length;i++) AY SSa 1}
{ A K/z6XGy
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #Y93y\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CodSJ,
nStartPos,nEndPos,i); XMRNuEU
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l+wc'=]
fileSplitterFetch.start(); .9|uQEL
} >J=<bhR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'ZQWYr9R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?`zgq>R}w[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n(lk dw
nEndPos = " + nFileLength); =/+#PVO
// fileSplitterFetch[nPos.length-1].start(); @-#T5?
=ZsGT
8@M'[jT
//等待子线程结束 gor<g))\
//int count = 0; a}d6o;li
//是否结束while循环 m_!U}!
boolean breakWhile = false; 0m+8P$)C%
x7RdZC
ACjf\4Q
while(!bStop) (\dK4JJ
{ Y'Z+, CNf
write_nPos(); sFb4`
Utility.sleep(500); sg'NBAo"
breakWhile = true; E=/[s]@5
,fnsE^}.U
TK>{qxt:=
for(int i=0;i<nStartPos.length;i++) 8,o17}NY,
{ idJh^YD
if(!fileSplitterFetch.bDownOver) C%ytkzG_
{ }`9`JmNM
breakWhile = false; qSQ@p\O~
break; .yVnw^gu
} b4 hIeBI\
} [U_[</L7
if(breakWhile) 4w{-'M.B
break; RI@*O6\/I
V2yveNz\7
,w&:_n
//count++; Sue 6+p
//if(count>4) bZ#X9fT
// siteStop(); 6~Wu`
} Q[s2}Z!N;
Y&,rTa
=w<VT%
System.err.println("文件下载结束！"); jX|=n.#q
} DuF7HTN[K
catch(Exception e){e.printStackTrace ();} 6.Bh3p
} fr#Qz{
s#lto0b"8
S!7g)
//获得文件长度 <*YO~S(R
public long getFileSize() G\1J _al
{ aqfL0Rg+`
int nFileLength = -1; Zu=kT}aGg
try{ 797X71>
URL url = new URL(siteInfoBean.getSSiteURL()); 9bEM#Hj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C6)R#
httpConnection.setRequestProperty("User-Agent","NetFox"); T_~KxQ
79z)C35~
CT}' ")Bm
int responseCode=httpConnection.getResponseCode(); ZT9IMihV
if(responseCode>=400) l.7d$8'\
{ g9qC{xd
processErrorCode(responseCode); zKJ.Tj W
return -2; //-2 represent access is error |yAK@Hl'
} A7(M,4`6
u&SZlkf6%
,xj3w#`zaf
String sHeader; Y*\6o7
kr{)
&A"e,h(^
for(int i=1;;i++) 966<I56+
{ tzNaw %\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h^d\xn9GT#
//Utility.log(in.readLine()); 7O461$4v
sHeader=httpConnection.getHeaderFieldKey(i); `r]TA]DR
if(sHeader!=null) HZuiVW8
{ 0h:G4
if(sHeader.equals("Content-Length")) /=trj5h
{ {~nvs4X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jIZ+d;1
break; *]'qLL7d
} 9ET/I$n
} *N'hA5.z
else nFj-<!
break; SJOmeN}4)
} 'f6PjI
} #~1wv^
catch(IOException e){e.printStackTrace ();} JE9>8+
catch(Exception e){e.printStackTrace ();} t]r7cA
NZ)b:~a
[88{@)
Utility.log(nFileLength); ;'hi9L
)"F5lOA6
>"bnpYSe
return nFileLength; -HN%B?}. x
} K@*rVor{
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j,4,zA1j|
//保存下载信息（文件指针位置） 'jN/~I
private void write_nPos() Y!;gQeC
{ m'SmN{(t
try{ &:q[-K@!
output = new DataOutputStream(new FileOutputStream(tmpFile)); N tO?
output.writeInt(nStartPos.length); p;F2z;#
for(int i=0;i<nStartPos.length;i++) Kc-Y
{ {:3.27jQ
// output.writeLong(nPos); .E#<fz
output.writeLong(fileSplitterFetch.nStartPos); @Mzz2&(dU
output.writeLong(fileSplitterFetch.nEndPos); {f&NStiB
} w/O<.8+
output.close(); {vLTeIxf.G
} *$JB`=Q
catch(IOException e){e.printStackTrace ();} 8i[".9}G\
catch(Exception e){e.printStackTrace ();} 6#fOCr;f7
} Q5hb0O%a
(eki X*y
>/8ru*Oc
//读取保存的下载信息（文件指针位置） v;Swo("
private void read_nPos() c1PViko,>
{ UBL(Nr
try{ ;x,+*%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9jqO/_7R+
int nCount = input.readInt(); -J{Dxz
nStartPos = new long[nCount]; 2rF?Q?$,B
nEndPos = new long[nCount]; V;H d)v(j
for(int i=0;i<nStartPos.length;i++) dFx2>6AZt
{ ]NbX`'
nStartPos = input.readLong(); 4U}zJP(L
nEndPos = input.readLong(); g'KzdG`O0
} LjSLg[i
input.close(); mVa?aWpez
} \5t`p67Ve_
catch(IOException e){e.printStackTrace ();} ,tcP=fdk]
catch(Exception e){e.printStackTrace ();} yI3Q|731)
} (W7;}gysh
w'!ECm>*`
.4H_Zt[2
private void processErrorCode(int nErrorCode) KbXbT
{ bK!,Pc<
System.err.println("Error Code : " + nErrorCode); u)tHOV>&
} Q^*G`&w,
mYiSR
D8)O4bh
//停止文件下载 UCe,2v%
public void siteStop() K5 5} Wi
{ zt-'SY
bStop = true; )?F$-~7
for(int i=0;i<nStartPos.length;i++) yT[Lzv#
fileSplitterFetch.splitterStop(); {9h`$e=
/!^L69um
7vii9Am7
} ls[Ls
} n33JTqX
//负责部分文件的抓取 [u/zrpTk
**FileSplitterFetch.java ;%BhhmR)[
*/ hO^&0?
package NetFox; 6W)xj6<@
j5PaSk&o=
U(rr vNt:t
import java.io.*; IUluJ.sXIf
import java.net.*; f%bc64N(
8|w5QvCU?3
Bv2z4D4f+
public class FileSplitterFetch extends Thread { zWF 5m )-
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A6{t%k~F
String sURL; //File URL >&$$(Bp
long nStartPos; //File Snippet Start Position Rf)'HT
long nEndPos; //File Snippet End Position 2>!_B\%)H
int nThreadID; //Thread's ID e*Uz#w:
boolean bDownOver = false; //Downing is over P]!LN\[
boolean bStop = false; //Stop identical ]NaMZ
FileAccessI fileAccessI = null; //File Access interface "2)+)Db
>Sc$R0
/Oq1q._9F
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S% JNxT7'
{ 2uvQf&,
this.sURL = sURL; ^m6k@VM
this.nStartPos = nStart; ddUjs8VvJ
this.nEndPos = nEnd; LVPt*S=/
nThreadID = id; NWo7wVwc/c
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Fy}MXe"f
} 3v9gb,)y\
L eG7x7n
'#cT4_D^lI
public void run() o7_MMeQ4
{ v YRt2({}Z
while(nStartPos < nEndPos && !bStop) Fpj6Atk
{ r*X}3t*
zCKy`u.
8\qCj.>S
try{ 7&;[an^w
URL url = new URL(sURL); d8Q_6(Ar|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R$!;J?SS
httpConnection.setRequestProperty("User-Agent","NetFox"); s=^r/Sz902
String sProperty = "bytes="+nStartPos+"-"; |QAeQWP+1
httpConnection.setRequestProperty("RANGE",sProperty); gFWEodx,9
Utility.log(sProperty); jMz1s%C
3bg4#c
s T :tFK\
InputStream input = httpConnection.getInputStream(); ]MqH13`)A
//logResponseHead(httpConnection); *j_fG$10g
IyG= 7
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byte[] b = new byte[1024]; Vq\..!y
int nRead; lRF_ k
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Se^/VVm
{ y(c|5CQ
nStartPos += fileAccessI.write(b,0,nRead); l6&v}M
//if(nThreadID == 1) an$]IN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rj2r#{[
} ?BHWzo!
]v^`+s}3
ecY ^C3+S
Utility.log("Thread " + nThreadID + " is over!"); E&iWtwkz
bDownOver = true; &J6o$i
//nPos = fileAccessI.write (b,0,nRead); F(KH-
} F$6])F
catch(Exception e){e.printStackTrace ();} A]tf>H#1
} a O"nD_7
} 9z|>roNe
Z!*8JaMT
DK@w^ZW6JA
//打印回应的头信息 UALg!M#
public void logResponseHead(HttpURLConnection con) 6PzN>+t^y
{ DmXDg7y7s
for(int i=1;;i++) Zv1Bju*y
{ MuFU?3ovG*
String header=con.getHeaderFieldKey(i); @R'g@+{I
if(header!=null) (Qx-KRH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \c9t]py<.h
Utility.log(header+" : "+con.getHeaderField(header)); _M"$5 T
else j?f,~Y<k
break; !dbA (
} 80s~ae;
} w}U5dM`
^7~SS2t!
+9Hk+.
public void splitterStop() _ntW}})K
{ FQ9csUjpB
bStop = true; bn*{*=(|
} _V7^sk!
MOqA$b
A=qW]Im
} J++sTQ(!?
2=Y_Qrhi
St3(1mApl
/* M[ ~2,M&H
**FileAccess.java 0IPhVG~#
*//文件访问(定位，写) 8Snq75Q<
package NetFox; OuBMVn
import java.io.*; [#Nx>RY
MR)KLM0
d'AviW>
public class FileAccessI implements Serializable{ uu@'02G8
m|ERf2-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }d~FTre
RandomAccessFile oSavedFile; ZTBFV/{
long nPos; 1&@wb'MBs.
vU$O{|J
B'gk/^6$eg
public FileAccessI() throws IOException [^(R1K
{ 0ZID @^
this("",0); F&L?J_=
} /<?X-IDz.{
[-Dgo1}Qr
dT,m{[+
public FileAccessI(String sName,long nPos) throws IOException 3Ibt'$dK
{ Ay"2W%([`
oSavedFile = new RandomAccessFile(sName,"rw"); 1M~:]}*<
this.nPos = nPos; [;CqvD<S
oSavedFile.seek(nPos); oIL+@}u7
} c7nk~K[6
G}dOx}kT
&v9PT!R~
public synchronized int write(byte[] b,int nStart,int nLen) }b]y 0"
{ sO4}kxZ
int n = -1; ;AL@<,8
try{ Pl5NHVr
oSavedFile.write(b,nStart,nLen); agxSb^ 8tF
n = nLen; KlqJEtO_
} /qhm9~4e3
catch(IOException e) ^1Zq0
{ %qjyk=z+Z
e.printStackTrace (); ??%T
} ::72~'tw
%J ( }D7-,
s8_NN
return n; GwpBDMk
} M Xt +
$?AUk
_:=OHURc
} Lz>{FOR
}`/n2
m6Cd^'J9^
/* wZ3vF)2s
**SiteInfoBean.java [U7,\o4w
*/ aj'8;E+
package NetFox; GoVPo'
}!7DF
=|V]8 tN
public class SiteInfoBean { E0B2>V
|&RX>UW$W
8YLZ)k'
private String sSiteURL; //Site's URL H6CGc0NS+
private String sFilePath; //Saved File's Path X-r,>o:
private String sFileName; //Saved File's Name nIKT w
private int nSplitter; //Count of Splited Downloading File DHNii_w4v
+?txGHQq
*9{Wn7pck/
public SiteInfoBean() f5qHBQ
{//nSplitter的缺省值为5 +ET
//default value of nSplitter is 5 M j%|'dZz
this("","","",5); rbZ6V :
} -L50kk>h
.,K?\WZ
$JSC+o(q3#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /z?7ic0
{ ;Owu:}
sSiteURL= sURL; qg:I+"u
sFilePath = sPath; Y~SlipY_
sFileName = sName; n*4X/K
this.nSplitter = nSpiltter; B|$13dHfa
>A( C9_\
A*U'SCg(G
} XaS_3d
H^1 a3L]
k^\&.63(
public String getSSiteURL() !vp!\Zj7o
{ j!o3g;j
return sSiteURL; GfPz^F=ie.
} ~#km0<r?
W3/Stt$D
r<"/P`r
public void setSSiteURL(String value) GaqG8%.
{ j3-6WUO
sSiteURL = value; >MY.Fr#.m
} J9c3d~YW
T*~)9o
F1*rUsRKN
public String getSFilePath() ftuQ"Ds
{ !!O{ ppM
return sFilePath; et}Y4,:
} `v2l1CQ:^
g*.(! !
=usDI<3r
public void setSFilePath(String value) i*w-Q=
{ yzR=:0J
sFilePath = value; RAQ;O
} "$cT*}br
8"UG&wLT
.p~;U|h"
public String getSFileName() VCRv(Ek
{ q=i<vcw
return sFileName; hdqls0 r
} H{zuIN/.1
oySM?ZE
U (7P X`1
public void setSFileName(String value) { (,vm}iFL
{ ts!aKx
sFileName = value; IqKXFORiNI
} Qnx92
Fe< t@W
b/Q"j3
public int getNSplitter() 5mVu]T`
{ .: ;Hh~
return nSplitter; "FvlZRfXj
} 'X<uG x
{;M/J
<r3n?w8
public void setNSplitter(int nCount) (kOv
{ k T>}(G||
nSplitter = nCount; y'/9KrV T
} 6ng g*kE<
} 08jQq#
Nj8)HR
`.WKU"To
/* Utp\}0GZY
**Utility.java *3Z#r
*/ u Aa>6R
package NetFox; --)[>6)I
(OJ9@_fgG[
(5;xs
public class Utility { f L?~1i =
dsuW4^l
S@($c'
public Utility() h9nCSj
{ =K8h)B_g
ka%pS
n\9*B##
} KrH;o)|
3$;v# P$%N
//线程睡眠 dUSuhT
public static void sleep(int nSecond) QNEaj\
{ '|R|7nQAj
try{ <:-&yDh u
Thread.sleep(nSecond); 42LV>X#i
} D40VJ3TUc
catch(Exception e) ,Z"sh*
{ R!CUR~F
e.printStackTrace (); ZVU)@[s
} )dcGV$4t[
} v8N1fuP}
$y}Tbm
//日志 Mla,"~4D5
public static void log(String sMsg) 4HAfTQ 1G
{ uESHTX/[
System.err.println(sMsg); 0IuU4h5Fr
} ]A[~2]
enM 3
?zqXHv#x
public static void log(int sMsg) nr;/:[F
{ zV#k #/$
System.err.println(sMsg); [$X(i|6
} #D8)rs.9
} Uz_{jAhW]
>EjBknl
nor`w,2VF
/* &#.&xc2sRZ
**TestMethod.java i8F~$6C
*/ o?=u#=
package NetFox; $[e*0!e
\)hmg
wqsnyP/m
public class TestMethod { UF4QPPH4
Zzs pE}
ezeGw?/
public TestMethod() xhv)rhu@
{ ///xx/weblogic60b2_win.exe ;F5%X\t-
try{ klKt^h-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -xXM/3g1u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6|9fcIh]B
SiteFileFetch fileFetch = new SiteFileFetch(bean); F7df
fileFetch.start(); eZHi6v)i
} X|as1Y$O+
catch(Exception e){e.printStackTrace ();} O<5bsKw'r
:iJ= 9
zKZ6Qjd8!
} 7)YU ;
uG<+IT|x
Sc(2c.HO*
public static void main(String[] args) ax$0J|}7
{ i^(0,L
new TestMethod(); zuOIos
} >13=4S
} /#HY-b
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