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)); k&iScMgCTH
} 4{WV
for(int i=0;i<nEndPos.length-1;i++) 0W%}z}/N
{ `R52{B#&/
nEndPos = nStartPos[i+1]; Zbh]SF{3F
} #_\MD,(
nEndPos[nEndPos.length-1] = nFileLength; q,JA~GG
} C;:L~)C@t
} q}v04Yy,o
)-:eQ{st`
^H6d;n
//启动子线程 1(7.V-(G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'qF3,Rw
for(int i=0;i<nStartPos.length;i++) TKu68/\)
{ q&d&#3Rh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3H}~eEg,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7e{X$'
nStartPos,nEndPos,i); SA+%c)j29
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L[Yp\[#-q
fileSplitterFetch.start(); {F+M&+``
} K0RYI69_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Dq%r !)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^!p<zZ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +[8Kl=]L
nEndPos = " + nFileLength); ]{2{:`s
// fileSplitterFetch[nPos.length-1].start(); Q] yT
0ij~e<
X$|TN+Ub
//等待子线程结束 !eAdm
//int count = 0; kbp( a+5
//是否结束while循环 2]aZe4H.
boolean breakWhile = false; x+y!P
j YIV^o 0
}8F$& AFt
while(!bStop) "i{_<;p O
{ x1V2|~;p|
write_nPos(); ^8oc^LOa~2
Utility.sleep(500); KWhM
breakWhile = true; u ?G\b{$m
Jt>[]g$
P`3s\8[Q
for(int i=0;i<nStartPos.length;i++) <r+!hJ[s'
{ ,*nZf|
if(!fileSplitterFetch.bDownOver) g y e(/N+I
{ <.=#EV^i
breakWhile = false; [bi3%yWh
break; vMZ7uO
} L_lDFF
} NBqV0>vR
if(breakWhile) gAr`hXO
break; _{c|o{2sj
/#qs(! d
<f.>jjwFE
//count++; NB W%.z
//if(count>4) [cQ<dVaTX
// siteStop(); B=gsd0^]
} ,v}?{pc
XHZ: mLf
Q%n{*py
System.err.println("文件下载结束！"); +r-dr>&H@
} >)n4sMq
catch(Exception e){e.printStackTrace ();} MB8SB
} #NN"(I
^?s~Fk_V
~C"k$;(n
//获得文件长度 :e&n.i^
public long getFileSize() gVnwsE
{ KM6N'x^z
int nFileLength = -1; Y1fy2\<'
try{ @k+%y'Y?
URL url = new URL(siteInfoBean.getSSiteURL()); q M_/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .A*VLF*m
httpConnection.setRequestProperty("User-Agent","NetFox"); oGJ*Rn)Z
W%>i$:Qq
XYb^Cs;
int responseCode=httpConnection.getResponseCode(); KZrMf77=
if(responseCode>=400) '6o`^u>
{ hEv=T'*,K)
processErrorCode(responseCode); CP]S-o}yd
return -2; //-2 represent access is error o=-Vt,2{
} b\?7?g
ljYpMv.>xG
. Z*j!{@c
String sHeader; # cN_y
mWli}j#
~&DB!6*
for(int i=1;;i++) a/QtJwIV
{ bB:r]*_ s]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3`fJzS%O
//Utility.log(in.readLine()); +HOCVqx
sHeader=httpConnection.getHeaderFieldKey(i); {K45~ha9!m
if(sHeader!=null) e8AjO$49
{ Y^f94s:2S
if(sHeader.equals("Content-Length")) $!|8g`Tm
{ jD'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JO2ZS6k[
break; 7b&JX'`Mb
} #+K Kvk
} fO^e+Mz
else cBLR#Yu;O5
break; 4{;8:ax&w
} ([,vX"4
} 1p7cv~#95
catch(IOException e){e.printStackTrace ();} 29Gwv
catch(Exception e){e.printStackTrace ();} EjR_-8@FK
CxbSj,
*GbVMW[A>
Utility.log(nFileLength); I*A0?{
3Q'[Ee2-3
~A`&/U
return nFileLength; HzRX$IKB3(
} ?Oy'awf_
E0"10Qbi
W.,% 0cZ
//保存下载信息（文件指针位置） R^J.?>0
private void write_nPos() t&GA6ML#s
{ 9VoDhsKk
try{ YgE]d?_h
output = new DataOutputStream(new FileOutputStream(tmpFile)); pk-yj~F}
output.writeInt(nStartPos.length); NP K#].F
for(int i=0;i<nStartPos.length;i++) V_&GYXx(J
{ 2;r]gT~
// output.writeLong(nPos); \{c,,th
output.writeLong(fileSplitterFetch.nStartPos); _tWJXv~;
output.writeLong(fileSplitterFetch.nEndPos); nG"tO'J6
} @+'c+
output.close(); }P<Qz^sr_
} 1~}m.ER
catch(IOException e){e.printStackTrace ();} yZYKwKG
catch(Exception e){e.printStackTrace ();} PsU9R#HL1
} L`9TB"0R+
UL86-R!
]2Sfkl0
//读取保存的下载信息（文件指针位置） Guk.,}9
private void read_nPos() <^lJr82
{ }3v'Cp0L
try{ $ A-+E\vQ@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); zRwb"
int nCount = input.readInt(); `]*%:NZP@
nStartPos = new long[nCount]; t)-*.qZh
nEndPos = new long[nCount]; H>60D|v[
for(int i=0;i<nStartPos.length;i++) {S[I_\3
{ A<4_DVd@@
nStartPos = input.readLong(); p"Ot5!F>
nEndPos = input.readLong(); Jy \2I{I'
} $.H:8^W
input.close(); $/u1chf
} Zimh_
catch(IOException e){e.printStackTrace ();} SArfczoB
catch(Exception e){e.printStackTrace ();} G1]"s@8(
} lj.nCV_
kTnOmAw
H@V 7!d
private void processErrorCode(int nErrorCode) sK+ (v
{ *_`76`cz%X
System.err.println("Error Code : " + nErrorCode); IQ ){(Y
} nD7|8,'
gks ==|s.
bf& }8I$
//停止文件下载 _p\629`
public void siteStop() &!ED# gs
{ ?2{bKIV_
bStop = true; z< z*Wz
for(int i=0;i<nStartPos.length;i++) 0y)}.'
fileSplitterFetch.splitterStop(); o4$Ott%Wm
25UYOK}!
_eGT2,D5r
} rkkU"l$v
} led))qd@V-
//负责部分文件的抓取 Mr-DGLJ
**FileSplitterFetch.java 6yY.!HRkr
*/ ~@{w\%(AK]
package NetFox; i=YXKe6fD
Bd{4Ae\_+g
Ng\/)^
import java.io.*; C)NC&fV
import java.net.*; /D]Kkm)
*c{wtl@
A]7<'el=
public class FileSplitterFetch extends Thread { >ajuk
*myG"@P4hW
Mtm/}I
String sURL; //File URL pe9@N9_5
long nStartPos; //File Snippet Start Position W4(v6>5l
long nEndPos; //File Snippet End Position sONBQ9
int nThreadID; //Thread's ID o/C(4q6d
boolean bDownOver = false; //Downing is over wuA^'T
boolean bStop = false; //Stop identical )l_@t(_
FileAccessI fileAccessI = null; //File Access interface +noZ<KFW "
S=' wJ@?;
Ht#@'x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zF8'i=b&
{ PocYFhWQ`
this.sURL = sURL; qD#VbvRc9+
this.nStartPos = nStart; syv$XeG=}
this.nEndPos = nEnd; x[QZ@rGIW
nThreadID = id; \i!Son.<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f;gZ|a
} 'Gjq/L/x
&rp!%]+xAM
RPVT*`o
public void run() VU|;:
{ Wqra8u#
while(nStartPos < nEndPos && !bStop) qos`!=g?
{ 1~J5uB4
%a];
5!Bktgk.
try{ ZU^IH9
URL url = new URL(sURL); n 6{2]&sd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MM?`voj~`p
httpConnection.setRequestProperty("User-Agent","NetFox"); piOXo=9H.
String sProperty = "bytes="+nStartPos+"-"; ,w{m3;]_%
httpConnection.setRequestProperty("RANGE",sProperty); 6-B 9na
Utility.log(sProperty); XF}rd.K:
#]9hTa IR
$+cAg>
InputStream input = httpConnection.getInputStream(); lv]quloT
//logResponseHead(httpConnection); f6!D L<
pQMtj0(y
B<7/,d'
byte[] b = new byte[1024]; e*C6uz9N
int nRead; 1DE@N1l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,Ol (piR
{ \hlR]m!C
nStartPos += fileAccessI.write(b,0,nRead); QV qK
//if(nThreadID == 1) '7*=`q{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aQ#qRkI
} w%dL8k
PmR*}Aw
Ri#H.T<'
Utility.log("Thread " + nThreadID + " is over!"); &3Z?UhH
bDownOver = true; <*|?x86~
//nPos = fileAccessI.write (b,0,nRead); #`;/KNp 9
} WZZ4]cC
catch(Exception e){e.printStackTrace ();} iWE)<h
} -Xz&}QA
} 5l DFp9
RKZ6}q1n
x0Yse:RE^
//打印回应的头信息 S[,8TErz
public void logResponseHead(HttpURLConnection con) |.P/:e9
{ Fl3#D7K
for(int i=1;;i++) WKmbNvN^
{ K>2#UzW
String header=con.getHeaderFieldKey(i); AW,OHSXh6
if(header!=null) K-eY|n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ifK%6o6
Utility.log(header+" : "+con.getHeaderField(header)); ~]'pY
else U7iuY~L
break; I]nHbghcW
} %O%=rUD
} \}_Yd8
s '?GH
.>pgU{C`!
public void splitterStop() uj|BQ`k
{ 8FkFM^\1L
bStop = true; a%BeqSZh
} -n5 B)uw=
}-@4vl x$
k(%QIJH
} >TjJA#
AoaN22
[xb]Wf
/* p?X02 >yA
**FileAccess.java al&(-#1
*//文件访问(定位，写) QHt4",Ij
package NetFox; `^9(Ot $
import java.io.*; _qXa=|}V.
xJs;v
"YU{Fkl#j
public class FileAccessI implements Serializable{ zsXoBD\h
wnLi2k/Dt<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m-/j1GZ*
RandomAccessFile oSavedFile; qTQ!jN
long nPos; *e#<n_%R
1w(JEqY3h:
jZoNi
public FileAccessI() throws IOException }/P5>F<H[
{ !T,AdNa8
this("",0); 8}e,%{q
} 6\jf|:h
sj?3M@l95W
Q,h7Sk*
public FileAccessI(String sName,long nPos) throws IOException C1EtoOv K
{ \C^;k%{LV
oSavedFile = new RandomAccessFile(sName,"rw"); A"5z6A4WB
this.nPos = nPos; XjioZ
oSavedFile.seek(nPos); b6(p
} ]iNEw9
-62'}%?A<C
eP.Vd7ky
public synchronized int write(byte[] b,int nStart,int nLen) SJt<+kg
{ 0c^>eq]
int n = -1; ;6ecrQMw&
try{ mo{MR:>)
oSavedFile.write(b,nStart,nLen); `(6r3f~XJ
n = nLen; G rmzkNlN
} kql0J|P?
catch(IOException e) Sn4[3JV$l
{ )u]9193
e.printStackTrace (); NcPgq?3p
} P +"Y
jw}}^3.
#@@Mxr'F
return n; 0Uk@\[1ox
} vsWHk7 9
hN2:d1f0
@+F4YJmB?l
} S [h];eM
%ek'~
Eodn/
/* fb~=Y$|
**SiteInfoBean.java + b$=[nfG
*/ -x8nQ%X
package NetFox; &!aAO(g
}]n$ %g(
5]I|DHmu
public class SiteInfoBean { zk*c)s
p Dx-2:}
e!Y0-=?nf#
private String sSiteURL; //Site's URL B+C);WQ,
private String sFilePath; //Saved File's Path (/-hu[:
private String sFileName; //Saved File's Name ae"]\a\&1o
private int nSplitter; //Count of Splited Downloading File :c9U>1`g&
6 5y+Z
:1XtvH
public SiteInfoBean() :l7U>~ o
{//nSplitter的缺省值为5 ~c)~015`
//default value of nSplitter is 5 ^<e@uNGg
this("","","",5); ~_s?k3cd
} / N)W2
@';B_iQ
b^D$jY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "H-"
{ \<}&&SuH
sSiteURL= sURL; y2]-&]&
sFilePath = sPath; \Y6WSj?E
sFileName = sName; bY}eUL2i4
this.nSplitter = nSpiltter; 'XY`(3q
[.RO'>2z
)o-Q!<*1
} t#%R q
'>$]{vQ3
E0%~!b
public String getSSiteURL() b@3_L4~
{ .q&'&~!_
return sSiteURL; k+I}PuG
} !RyO\>:q
\#o2\!@`
/%_OW@ ?
public void setSSiteURL(String value) fwK}/0%
{ (b'B%rFO
sSiteURL = value; [7_56\G4
} |#6QThK
3^s/bm$g
.h0b~nI>>
public String getSFilePath() &>e-(4Xu
{ N2.AKH
return sFilePath; :Mm3 gW)
} Y"-^%@|p
k} ]T;|h]
\J+*
public void setSFilePath(String value) 8NaqZ+5x
{ "#(T
sFilePath = value; }y9mNT
} ^Y-]*8;]
T\w?$ s
kP/M<X"
public String getSFileName() v1a6?-
{ gX0R)spg
return sFileName; r$]HIvJD
} u7?$b!hG^C
rQ7+q;[J
?wnzTbJN
public void setSFileName(String value) vjjSKP6B
{ ,+~rd4a
sFileName = value; \P1S|ufv
} K&8dA0i2u2
k)TSR5A
kcb.Wz~=
public int getNSplitter() JyR/1 W
{ sKlDu
return nSplitter; ooUk O
} N^Bo .U0\
-V:"l
t3dlS`O
public void setNSplitter(int nCount) TLoz)&@
{ kOh{l: 2-+
nSplitter = nCount; Gs3LB/8?
} uYE`"/h,1e
} z{Mr$%'EY
0ez(A
B'^:'uG
/* L#vI=GpL,r
**Utility.java &ZL3{M
*/ tK&'<tZh
package NetFox; 5Ri6Z#qm
F <hJp,q9
rXA*NeA3v
public class Utility { vDH>H^9Y
qhT@;W/X
7O,U?p
public Utility() !9xp cQ>
{ ~ o1x;Y6
271&i
6M13f@v
} (PfqRk1Y
>Wz;ySEz
//线程睡眠 msVOH%wH
public static void sleep(int nSecond) LVJxn2x6
{ sJ]taY ou
try{ ;A#`]-i C
Thread.sleep(nSecond); JA)] _H P
} Ot]Ru,y->+
catch(Exception e) `[C!L *#,
{ 7EXI6jGJ|
e.printStackTrace (); )c8j}
} otk}y8
} U#3J0+!
sP ls zC[
//日志 +|tC'gCnV
public static void log(String sMsg) 1x[)/@.'f
{ }[M`uZ
System.err.println(sMsg); :UQTEdc{
} RIIitgV_
nxr!`^Mne
ATR!7i\|
public static void log(int sMsg) +wkjS r`e
{ +zy=50,
System.err.println(sMsg); D}vmwg@3
} F$[ U|%*
} o`Ta("9^
rD*sl}
y K"kEA[;
/* XP@1~$
**TestMethod.java 8stwg'
*/ =9j8cC5y
package NetFox; F+@5C:<?
s>^dxF!+
e[8LmuIZ
public class TestMethod { u?9" jX
!%c'$f/
clk[/'1
public TestMethod() ,mj@sC>
{ ///xx/weblogic60b2_win.exe ~q~MoN<R
try{ w+N> h;j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aXL{TD:]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U4cY_p?
SiteFileFetch fileFetch = new SiteFileFetch(bean); z@wMc EH
fileFetch.start(); {c (!;U
} og0*Nt+
catch(Exception e){e.printStackTrace ();} *W kIq>
f"St&q>[s
O)"gS!,
} 9D4NX<_
J&T.(
'{(UW.Awo
public static void main(String[] args) 0X^Ke(/89
{ ;g~TWy^o
new TestMethod(); #y%!\1M/:A
} <A# l 35
} KG=h&
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