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)); }[I|oV5*+&
} ^<O:`c6_
for(int i=0;i<nEndPos.length-1;i++) cc$+"7/J^c
{ {!vz 6QDS
nEndPos = nStartPos[i+1]; w`OHNwXh#I
} CI6qDh6
nEndPos[nEndPos.length-1] = nFileLength; Gu136XiX
} Qws#v}xF
} z"lRfOWI
1~P ^g`
\muC_9ke
//启动子线程 )|@UY(VZ^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (s.S n(E
for(int i=0;i<nStartPos.length;i++) ur2`.dY>3"
{ 9}6^5f?|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =2[U4<d!R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~2*8pb 4
nStartPos,nEndPos,i); gT6@0ANq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B%Spmx8
fileSplitterFetch.start(); K%"cVqb2V
} 1~#p3)B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?QXo]X;f&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D2}nJFR ]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &D~70N\L
nEndPos = " + nFileLength); ,*@6NK,.
// fileSplitterFetch[nPos.length-1].start(); bbU{ />yW
p#dpDjh
,M&[c|
//等待子线程结束 +Ss|4O}'
//int count = 0; W:16qbK
//是否结束while循环 `Z0#IeX=
boolean breakWhile = false; .v:K`y;f\(
]%5DuE\M8\
S?_ ;$Cn
while(!bStop) 3QrYH @7zx
{ pJE317 p'
write_nPos(); U ]6Hml;l
Utility.sleep(500); pB;p\9A*q
breakWhile = true; L?n*b
<ctn_"p Z
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for(int i=0;i<nStartPos.length;i++) If_S_A c
{ nP>*0Fq
if(!fileSplitterFetch.bDownOver) >K9uwUi|b]
{ O2Mo ~}
breakWhile = false; bu#}`/\_
break; 7=ZB?@bU~
} lS(?x|dO
} @u2nG:FG
if(breakWhile) 'L2M W
break; oA&V,r
6Hn3
}GCt)i_
//count++; Oj*3'?<7=
//if(count>4) &V&0kp@+
// siteStop(); 0iX;%SPYz
} QpPJ99B|
A8R}W=
dSb|hA}@
System.err.println("文件下载结束！"); ?b~Vuo
} j9za)G-J
catch(Exception e){e.printStackTrace ();} ~o+HAc`=v
} y$At$i>u
x.+}-(`W#~
#is:6Z,OEU
//获得文件长度 D/Y.'P:j
public long getFileSize() .sA?}H#wb
{ #<bt}Tht
int nFileLength = -1; @hiwq7[j
try{ u9FXZK7
URL url = new URL(siteInfoBean.getSSiteURL()); +]Y&las
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +t R6[%
httpConnection.setRequestProperty("User-Agent","NetFox"); $3sS&i<
!0~$u3[b
+?~'K&@
int responseCode=httpConnection.getResponseCode(); u4=j!Zb8}
if(responseCode>=400) e1X*}OI
{ z1ltc{~Z
processErrorCode(responseCode); s45Y8!c
return -2; //-2 represent access is error Yo c N@s
} (@dh"=Lt\
Qcz7IA
_{o=I?+]
String sHeader; N(@'L43$V
S"UFT-N
yk9|H)-z
for(int i=1;;i++) /)xG%J7H
{ u|7d_3 ::
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Mrp'wF D
//Utility.log(in.readLine()); 8Z!+1b
sHeader=httpConnection.getHeaderFieldKey(i); elZ?>5P$}
if(sHeader!=null) KD^>Vv#
{ ]+W+8)f1M
if(sHeader.equals("Content-Length")) !p1OBS|
{ Gv}*Tw$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Pt?]JJxl-
break; RR><so%
} J56+eC(
} Te~"\`omJ3
else jBV2]..
break; uRQm.8b
} SU9#Y|I
} Pn5@7~
catch(IOException e){e.printStackTrace ();} cX@~Hk4=\
catch(Exception e){e.printStackTrace ();} o*\kg+8
)kl| 5i
>UpTMEQ
Utility.log(nFileLength); 3mgFouX2x,
"';'*x
zqqpBwk#
return nFileLength; 5,'?NEyw
} [SgP1>M
/J8AnA1
0i9y-32-
//保存下载信息（文件指针位置） jNV2o
private void write_nPos() #JGy2Hk$^
{ W?G4\ubM3<
try{ r+0"1\f3
output = new DataOutputStream(new FileOutputStream(tmpFile)); l'VgS:NT
output.writeInt(nStartPos.length); ]6</{b
for(int i=0;i<nStartPos.length;i++) I~MBR2$9
{ yE-&TW_q:>
// output.writeLong(nPos); @dcT8 YC
output.writeLong(fileSplitterFetch.nStartPos); 9tXLC|yl?
output.writeLong(fileSplitterFetch.nEndPos); *"0Yr`)S
} pK4I?=A'
output.close(); J /'woc
} q,2]]K7y
catch(IOException e){e.printStackTrace ();} `|i #)
catch(Exception e){e.printStackTrace ();} B}gi /
} nbw&+dcJ8
i)\`"&.j>N
tOwwgf
//读取保存的下载信息（文件指针位置） q~r)B}
private void read_nPos() \CB{Ut+s
{ LS4c|Dv
try{ cg<10KT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o)cd!,h
int nCount = input.readInt(); r~u/M0h `
nStartPos = new long[nCount]; \*!?\Ko`W
nEndPos = new long[nCount]; QR'"Zw&q5/
for(int i=0;i<nStartPos.length;i++) @h([c
{ n w @cAv
nStartPos = input.readLong(); |v}"UW(y
nEndPos = input.readLong(); ,m!j2H}8
} R*E/E
input.close(); }?#<)|_5
} \rcbt6H
catch(IOException e){e.printStackTrace ();} 6J6MR<5'
catch(Exception e){e.printStackTrace ();} 1fQvh/2
} >ALU}o/
B>t$Z5Q^X
O:RPH{D
private void processErrorCode(int nErrorCode) 9C$b^wHd
{ 8=T;R&U^M
System.err.println("Error Code : " + nErrorCode); T%KZV/
} %]>c4"H
WhSQ>h!@s
+XJj:%yt
//停止文件下载 u=jF\W9
public void siteStop() 9<WMM)
{ f/?# 1
bStop = true; _C&2-tnp
for(int i=0;i<nStartPos.length;i++) -fz |
fileSplitterFetch.splitterStop(); .jZmQtc
}-)2CEj3L%
[U]*OQH`e
} A"\kdxC
} R(=Lhz6R4
//负责部分文件的抓取 b3MgJT"mN
**FileSplitterFetch.java 6~0S%Hz
*/ Y1H8+a5@
package NetFox; q+3Z3v
,!|/|4vh
. 3=WE@M
import java.io.*; y^pk)`y8
import java.net.*; RhnSQe
bec n$R
$f*N
public class FileSplitterFetch extends Thread { }qG{1Er
&'N{v@Oi)
d%81}4f:
String sURL; //File URL wZh&w<l'
long nStartPos; //File Snippet Start Position @xmO\
long nEndPos; //File Snippet End Position v6HBO#F'V{
int nThreadID; //Thread's ID iT%aAVs
boolean bDownOver = false; //Downing is over /lx\9S|
boolean bStop = false; //Stop identical hkJ4,.
FileAccessI fileAccessI = null; //File Access interface 3@J0-w
1@P/h#_Vr
k)b}"' I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o <0f
{ 8V;@yzIha
this.sURL = sURL; )~T)$TS
this.nStartPos = nStart; _jR%o1Y}
this.nEndPos = nEnd; dfiA- h
nThreadID = id; h$DFp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OlK3xdg7
} xSs);XO,
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^L+*}4Dr
public void run() ,_r"=>?@
{ wW1aG
while(nStartPos < nEndPos && !bStop) gV):3mWC
{ KIC5U50J
d `>M-:dF
&xgMqv2/
try{ s-}|_g.Pt
URL url = new URL(sURL); JWr:/?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wXMKQ)$(
httpConnection.setRequestProperty("User-Agent","NetFox"); KF|+#qCN
String sProperty = "bytes="+nStartPos+"-"; >t)vQ&:;u
httpConnection.setRequestProperty("RANGE",sProperty); U>IllNd
Utility.log(sProperty); !Sy._NE`z
Y _m4:9p
,u#uk7V
InputStream input = httpConnection.getInputStream(); =GL}\I
//logResponseHead(httpConnection); }\:3}'S.$
xKWqDt
1Zx|SBF
byte[] b = new byte[1024]; HlqCL1\<
int nRead; 4!i`9w$$"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u01 'f-h
{ [!]a' T#x
nStartPos += fileAccessI.write(b,0,nRead); L$cNxz0$
//if(nThreadID == 1) \6-x~%xK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }tF/ca:XPQ
} Ds9pXgU(Z
od{Y` .<
L)a8W
Utility.log("Thread " + nThreadID + " is over!"); OKNA36cU'
bDownOver = true; YFv/t=`
//nPos = fileAccessI.write (b,0,nRead); nW3-)Q89
} yMq&9R9F
catch(Exception e){e.printStackTrace ();} UQ:H3
} ;o8C(5xE|
} NKvBNf|D
dFS>uIT7X
+(x^5~QX
//打印回应的头信息 &M,a+|yuY
public void logResponseHead(HttpURLConnection con) cTCo~Pk4
{ MIo<sJuv
for(int i=1;;i++) k*(c8/<.d
{ q&Y'zyHLP
String header=con.getHeaderFieldKey(i); gS_)(
if(header!=null) vp?87h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0^az<!!O#
Utility.log(header+" : "+con.getHeaderField(header)); E0'+]"B
else =@AWw:!:,
break; V&;1n
} J 05@SG':
} a|SgGtBtT4
OXe+=Lp<
[9(tIb!x
public void splitterStop() t.$3?"60~
{ H;s
bStop = true; BAG) -
} XE* @*
7Ab&C&3
4sasf94
} SeN4gr*
}l~|c{WH`
L^i=RGx
/* Nz_c]3_j
**FileAccess.java M$~3`n*^
*//文件访问(定位，写) $m,gQV~4
package NetFox; cjAKc|NJ
import java.io.*; Ef{rY|E
@wy|l)%
id<i|
public class FileAccessI implements Serializable{ |t+M/C0y/
)Fx"S.Ok
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9]fhH
RandomAccessFile oSavedFile; M(|Qvh{Q6
long nPos; v".q578 0B
fftFNHP
JQ=i{9iJ
public FileAccessI() throws IOException T]-yTsto
{ eQu%TZ(x-$
this("",0); <f.*=/]W2
} gF-<%<RV
dU1w)Y
n8UQIa4&=
public FileAccessI(String sName,long nPos) throws IOException $R(?@B(
{ 5b45u 6
oSavedFile = new RandomAccessFile(sName,"rw"); x|U~?
this.nPos = nPos; s0uI;WMg
oSavedFile.seek(nPos); SF$7WG3Q
} >$SP2(Y~
&[:MTK?x!
;Pf |\q
public synchronized int write(byte[] b,int nStart,int nLen) [ -"o5!0<
{ gNF8&T
int n = -1; F1)B-wW
try{ vQ/}E@?u
oSavedFile.write(b,nStart,nLen); +^ a9i5
n = nLen; bP\0S@1YL
} QA>(}u\+
catch(IOException e) qzS 9ls>>
{ CF"$&+s9
e.printStackTrace (); 59mNb:<
} K~ ,|~
ZycV?ob8}
5I/wP qR[
return n; 1{l18B`
} Ri4t/H
2w\$}'
J@D5C4>i
} U"$Q$ OFs
6hDK;J J&
b?9c\-}
/* i{[=N9U5o
**SiteInfoBean.java (uW/t1
*/ qcMVY\gi
package NetFox; i;Cs,Esnf
pm$2*!1F(
K*iy^}
public class SiteInfoBean { ,<?iL~> %
d\aKGq;8C
u>c\J|K_V
private String sSiteURL; //Site's URL 9rXbv4{
private String sFilePath; //Saved File's Path w}+#w8hu
private String sFileName; //Saved File's Name x{4Rm,Dxn
private int nSplitter; //Count of Splited Downloading File GslUN% UJr
HDQhXw!!hc
T'\B17 :*
public SiteInfoBean() !OWPwBm;
{//nSplitter的缺省值为5 h/~:}Bof
//default value of nSplitter is 5 r>73IpJI
this("","","",5); #p&&w1
} !Ic;;<
4;"^1 $
A{\#.nC/z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )006\W|t9
{ 1Vq]4_09g1
sSiteURL= sURL; lOIBX@K E
sFilePath = sPath; mr:;Wwd
sFileName = sName; Yhdt"@;..
this.nSplitter = nSpiltter; Q#C;4)e
_y#omEx
HT]W2^k
} H`u8}{7
,M2u (9
A4LGF
public String getSSiteURL() Z$qFjWp
{ 3t<XbHF9
return sSiteURL; U'^AJ2L8
} +5J"G/f
'J^ M`/
bwh7.lDAl
public void setSSiteURL(String value) kN3T/96
{ tP; &$y.8
sSiteURL = value; )|;*[S4
} `nBCCz'Y!
nQ|4.e;
/H#- \r&r
public String getSFilePath() 2|'v[
{ WrK!]17or
return sFilePath; rZRcy9$y>
} gcYx-gA}
>!+.M9
xlPUum-o
public void setSFilePath(String value) TDI8L\rr
{ wMy$T<:
sFilePath = value; m"Y;GzqQl
} xml@]N*D#E
49f- u
\s<7!NAE4
public String getSFileName() :}d`$2Dz
{ J ytY6HF
return sFileName; .qVz rS
} OJd!g/V
6BIP;, M=
Xx{ho4qq
public void setSFileName(String value) wX}N===
{ ;\`~M
sFileName = value; Enee\!@v
} ~;St,Fw<<
+EJwWDJ!%
+|.}oL^}G
public int getNSplitter() !_GY\@}
{ 4)D#kP
return nSplitter; mhnjYK9
} Zu(eYH=Q
8@%Xd^
[% chN/
public void setNSplitter(int nCount) }Ictnb
{ "=4`RM
nSplitter = nCount; HZMs],GX
} QX(x6y>Q
} #.O,JG#H
:T~Aa(%(
\8\)5#?
/* f.V;Hl,
**Utility.java qh Ezv~
*/ A^7!:^%K
package NetFox; VlKy6PSIg
||v=in
2mL1BG=Yk
public class Utility { t}-[^|)7
]D^dQ%{
'Z2:u!E
public Utility() r})2-3ZA9
{ gA ]7YHc
mhTpR0
ZK5(_qW&i
} 3oX%tx
4X7y}F.J
//线程睡眠 Wz$%o'OnC
public static void sleep(int nSecond) @k~?h=o\b
{ ToNi<~
try{ 8?] :>
Thread.sleep(nSecond); '$Jt}O
} eydVWVN
catch(Exception e) ln.kEhQ3B
{ 8D]:>[|E
e.printStackTrace (); n+@}8;oeP
} g+/%r91hZ
} !- f>*|@
lJ]r%YlF
//日志 !f_GR Pj'
public static void log(String sMsg) P# 2&?.d\
{ 2=ZR}8}9Q:
System.err.println(sMsg); Z+ubc"MVb
} >4TJH lB}8
FzmCS@yA
k*|dX.C:
public static void log(int sMsg) 2rHw5Wn]~
{ Wu)ATs}
System.err.println(sMsg); Sp)KtMV
} SCeZt [
} RAKQ+Y"nl
ANSvZqKh
9[DQ[bL
/* nPq\J~M
**TestMethod.java ~\dpD
*/ >_M}l@1
package NetFox; >V(>2eD'S
.jMm-vox}
a:@9GmtV&
public class TestMethod { vy/U""w`
zF/}s_><*
[i[G" %Q
public TestMethod() vZ 4Z+;.
{ ///xx/weblogic60b2_win.exe 4zghM<
try{ jIE>t5 fy
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kFv\V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )DMu`cD
SiteFileFetch fileFetch = new SiteFileFetch(bean); )ufHk
fileFetch.start(); DGY#pnCu
} yb/< 7
catch(Exception e){e.printStackTrace ();} W9 y8dw.
Orh5d7+S
uZZ[`PA(
} 3M{!yPlj
rP ;~<IxEr
(Wr;:3i
public static void main(String[] args) 'R_U,9y`
{ D,xWc|V
new TestMethod(); qt]QO1pAd
} v,vTRrpK
} 0!=e1_
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