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)); =6Ihk
} 7ae8nZ3&
for(int i=0;i<nEndPos.length-1;i++) t[XxLG*
{ ;gu_/[P
nEndPos = nStartPos[i+1]; U8PSJ0ny
} ZC@sUj"
nEndPos[nEndPos.length-1] = nFileLength; $RfM}!7?
} XL1v&'HLV
} swntz
5\A[ra
_t_X`
//启动子线程 mvyqCOp0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; VZ5EV'D8!
for(int i=0;i<nStartPos.length;i++) j ~:Dr
{ CfNHv-jDL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rfpeX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Gcna:w>6d
nStartPos,nEndPos,i); qe8dpI;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OEnJ".&V
fileSplitterFetch.start(); : 2Ho
} TW8E^k7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %XMwjBM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |<t"O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s`B"qw
nEndPos = " + nFileLength); lED-Jo2
// fileSplitterFetch[nPos.length-1].start(); h/j+b.|
R_e{H^pY^
PMebn$(
//等待子线程结束 Q-k{Lqa-
//int count = 0; mFC0f?nr
//是否结束while循环 mzLDZ#=b
boolean breakWhile = false; I9-vV>:z
Y9F!HM-`
|W];8
while(!bStop) n[H3b}
{ t9685s
write_nPos(); ,A T!:&<X
Utility.sleep(500); NguJ[
breakWhile = true; `9}\kn-</8
- &Aw]+
wws)**]J8
for(int i=0;i<nStartPos.length;i++) &`[y]E'
{ </3Shq
if(!fileSplitterFetch.bDownOver) ]([:"j
{ dh#4/Wa,
breakWhile = false; rLw3\>y
break; n7>CK?25
} 0!!b(X(
} S\RjP*H*
if(breakWhile) RsIR}.*
break; <2Lcy&w_M
Bvj-LT=)
{%.FIw k
//count++; O:cta/M
//if(count>4) c%9wI*l
// siteStop(); TO7%TW{L
} !*_5 B'
v<c~ '?YzO
!r]elX
System.err.println("文件下载结束！"); }>Gnpc
} P~$FgAV
catch(Exception e){e.printStackTrace ();} :oh(M|;/2
} u4*7n-(
BQq,,i8H
bU9B2'%E
//获得文件长度 t2d_XQOK
public long getFileSize() /^v?Q9=Y
{ #-?pY"N,
int nFileLength = -1; o_>id^$>B
try{ a<9cj@h
URL url = new URL(siteInfoBean.getSSiteURL()); WDc2Qt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5|&8MGW-$
httpConnection.setRequestProperty("User-Agent","NetFox"); b37P[Q3
P[6@1
6UOV,`:m+
int responseCode=httpConnection.getResponseCode(); *$mDu,'8
if(responseCode>=400) *)+1BYMo
{ lX$6U|!
processErrorCode(responseCode); G66A]FIg
return -2; //-2 represent access is error 8@S7_x
} EkS7j>:
q|,cMPS3
!m)P*Lw
String sHeader; >Q':+|K}
SZW+<X
M il ![A1
for(int i=1;;i++) +Gv{Apd"
{ 2gLa4B-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &(a#I]`9M
//Utility.log(in.readLine()); a'=C/ s+
sHeader=httpConnection.getHeaderFieldKey(i); ^{\gD23
if(sHeader!=null) 7DaMuh~<
{ c#X9d8>
if(sHeader.equals("Content-Length")) +rse,b&U(
{ _X5@%/Vz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9fp@d
break; 2]W"sT[
} qd\5S*Z1
} Cj^:8 ?%
else )vVt{g
break; Ln/6]CMl
} l`D^)~o8
} ."9t<<!
catch(IOException e){e.printStackTrace ();} ;O` \rP5w
catch(Exception e){e.printStackTrace ();} s*$Re)}S
^M36=~j
'ap<]mf2
Utility.log(nFileLength); rF C6"_
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J-C3k`%O
return nFileLength; ,Y 1&[
} `QC
pUtd_8
*PQu9>1w
//保存下载信息（文件指针位置） v,z s dr"d
private void write_nPos() 0IU>KGJ-0s
{ PAG.],"D
try{ MJJ]8:%
output = new DataOutputStream(new FileOutputStream(tmpFile)); GQ<]Sd}[
output.writeInt(nStartPos.length); h&Thq52R
for(int i=0;i<nStartPos.length;i++) ?Ne@OMc
{ =\CJsS.
// output.writeLong(nPos); 9+<%74|,
output.writeLong(fileSplitterFetch.nStartPos); $B6CLWB
output.writeLong(fileSplitterFetch.nEndPos); @pq#?
} .Y B}w
output.close(); HsrIw
} O%RkU?ME
catch(IOException e){e.printStackTrace ();} jSa9UD
catch(Exception e){e.printStackTrace ();} Q|40 8EM
} X"QIH|qx-
fh~"A`d
R Fgy
//读取保存的下载信息（文件指针位置） EX^}#|e*h
private void read_nPos() ];BGJ5^j
{ z"/Mva3|
try{ 4u}"ng
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #sl_ BC9
int nCount = input.readInt(); 2uonT,W
nStartPos = new long[nCount]; {ctEjgiE
nEndPos = new long[nCount]; cBICG",TA
for(int i=0;i<nStartPos.length;i++) H:9Z.|{Gv
{ "-aak )7w
nStartPos = input.readLong(); JNhHQvi\
nEndPos = input.readLong(); w`Q"mx*
} 0Y rdu,c
input.close(); c)H(w
} 4dy2m!
catch(IOException e){e.printStackTrace ();} -dX{ R_*
catch(Exception e){e.printStackTrace ();} |Z%I3-z_DS
} Xk#"rM< Y
7P3PQ%:
b=:$~N@Y
private void processErrorCode(int nErrorCode) _isqk~ ul
{ TMt,\gTd
System.err.println("Error Code : " + nErrorCode); =gI;%M\'
} 4o,%}bo&
>:W7f2%8`
>7@kwj-f)
//停止文件下载 =+um:*a.
public void siteStop() a*4"j2j v
{ Lg[v-b=?I
bStop = true; QF^_4Yn
for(int i=0;i<nStartPos.length;i++) YTBZklM
fileSplitterFetch.splitterStop(); 'qD5
Cj).
cd8ZZ8L
} [hy:BV6H+
} gH87e
//负责部分文件的抓取 x!\FB.h4!(
**FileSplitterFetch.java |~'D8 g:Ak
*/ J?/.|Y]e
package NetFox; }sTo,F$
u<8 f;C_
s|3@\9\
import java.io.*; ]8,:E ]`O
import java.net.*; k+k&}8e
$'$#Xn,hU
f.f5f%lO~
public class FileSplitterFetch extends Thread { U)oH@/q
?O1:-vpZ
f"XFf@!
String sURL; //File URL g8+w?Zn}
long nStartPos; //File Snippet Start Position p#vZYwe=L
long nEndPos; //File Snippet End Position 0,)Ao8
int nThreadID; //Thread's ID _ED,DM
boolean bDownOver = false; //Downing is over J&,N1B
boolean bStop = false; //Stop identical }@IRReQ
FileAccessI fileAccessI = null; //File Access interface e|wH5(V
z4l O
T';<;6J**
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %(4G[R[
{ ~$g$31/
this.sURL = sURL; tPO\e]
this.nStartPos = nStart; .E!p
this.nEndPos = nEnd; }5n((7@X
nThreadID = id; <0[{Tn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <:#O*Y{
} n^QOGT.s6`
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@\gTi;u/x
public void run() /EY^ui
{ f'/@h Na3
while(nStartPos < nEndPos && !bStop) s>sIji
{ 2N]u!S;d
W":is"
COS(pfC
try{ mT N6-V
URL url = new URL(sURL); g*UI~rp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oo\0X
httpConnection.setRequestProperty("User-Agent","NetFox"); YJgw%UVJ5m
String sProperty = "bytes="+nStartPos+"-"; Ks&~VU
httpConnection.setRequestProperty("RANGE",sProperty); f.Y9gkt3d
Utility.log(sProperty); ?sl 7C gl
3Rid1;L0U
OHnHSb'?\
InputStream input = httpConnection.getInputStream(); AYHfe#!
//logResponseHead(httpConnection); sPNX)
DbSl}N;
4-q7o]%5<
byte[] b = new byte[1024]; Uo{h. .7?
int nRead; _]E ~ci}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) # k+Ggw
{ rl)(4ad=
nStartPos += fileAccessI.write(b,0,nRead); 9GnNL I{
//if(nThreadID == 1) riI0k{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +Ux)m4}j
} NLDmZra
A.9,p
W>b(hVBE
Utility.log("Thread " + nThreadID + " is over!"); &]~z-0`$!
bDownOver = true; `Rj<qz^7
//nPos = fileAccessI.write (b,0,nRead); STgl{#
} 6y)xMX
catch(Exception e){e.printStackTrace ();} %hU8ycI*h
} jY-i`rJN
} %8H*}@n
0pYz8OB
b2 ~~!C
//打印回应的头信息 y(|6`
public void logResponseHead(HttpURLConnection con) 76[aOC2Ad
{ U{D ?1tF
for(int i=1;;i++) F#_7mC
{ JJ56d)37.
String header=con.getHeaderFieldKey(i); XF2u<sDe
if(header!=null) &0TOJ:RP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); rWbuoG+8
Utility.log(header+" : "+con.getHeaderField(header)); !lE (!d3M
else Oa~t&s
break; k%QhF]
} zQxZR}'
} tklU zv
IoNZ'g?d
T3['6%
public void splitterStop() GFvZdP`s4
{ , j,[4^
bStop = true; >H@ dgb
} }M f}gCEW
9A\J*OU
VS^%PM#:/
} 3a#637%
%Zx/XMs}e
IDzP<u8v
/* yuswWc'
**FileAccess.java TEB%y9
*//文件访问(定位，写) ?7G?uk]3,@
package NetFox; xXZ$#z\Z,
import java.io.*; N##T1 Qm)
=KNg "|
e~J% NU'&
public class FileAccessI implements Serializable{ q=bJ9iJsq
<(d^2-0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1*?IDYB
RandomAccessFile oSavedFile; XPzwT2_E
long nPos; `a:@[0r0U
Y,WcHE
iUA2/ A
public FileAccessI() throws IOException >;o^qi_$
{ ZcX%:ebKS
this("",0); FHM^x2
} $ sEe0
*%ZfE,bu8<
Gyy:.]>&
public FileAccessI(String sName,long nPos) throws IOException 8NeP7.U<w
{ -O~WHi5}
oSavedFile = new RandomAccessFile(sName,"rw"); |IH-a"
this.nPos = nPos; 0"u*Kn
oSavedFile.seek(nPos); j3`:;'L
} ^]wm Y
+Qu~UK\
-N5r[*>
public synchronized int write(byte[] b,int nStart,int nLen) /.05rTpp
{ QfU 0*W?r
int n = -1; GfQMdLy\Z
try{ ;eG%#=>
oSavedFile.write(b,nStart,nLen); bm%2K@ /U
n = nLen; 2b1LC!'U
} ..<(HH2
catch(IOException e) l/LRr.x
{ ezwcOYMXK
e.printStackTrace (); :@_CQc*yB
} E(8!VY ^
FO3!tJ\L
lhQ*;dMj%"
return n; Ca+d ?IS
} bLu6|YB
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} #k)G1Y[c
sPkT>q
,2H5CFX/
/* OD>-^W t;%
**SiteInfoBean.java ; {I{X}b
*/ rVQ:7\=Z
package NetFox; u9mMkzgSkP
/CKkT.Le
"TtK!>!.
public class SiteInfoBean { a+\Gz
~<v`&Gm?"
M%&`&{
private String sSiteURL; //Site's URL }kL%l
private String sFilePath; //Saved File's Path q7 Uu 8JXF
private String sFileName; //Saved File's Name ?Dd2k%o
private int nSplitter; //Count of Splited Downloading File hpWAQ#%oHm
]N1$ioC#
+t.T+` EG
public SiteInfoBean() A!iH g__/t
{//nSplitter的缺省值为5 gADt%K2#Z
//default value of nSplitter is 5 $6fHY\i#R
this("","","",5); \jq1F9,
} *I'O_D
.vQ2w
n0Ze9W+<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e"^1- U\
{ MB^b)\X
sSiteURL= sURL; $Ae/NwIlc
sFilePath = sPath; Kh<v2
sFileName = sName; ;1{S"UY
this.nSplitter = nSpiltter; vU{ZB^+&6o
2Y 6/,W
a^Zn }R r
} 4pA<s-
#J2856bzS
?/dz!{JC
public String getSSiteURL() `mCcD
{ >Cd%tIie*
return sSiteURL; q;kMeE*
} u#J5M&#
.^JID~<?#
>)#*}JI
public void setSSiteURL(String value) ynP^|Ou
{ 9Eg'=YJ
sSiteURL = value; Wt8;S$!=R
} LfgR[!
dhm;
A FfgGO
public String getSFilePath() xu+wi>Y^
{ NSHlo*)}
return sFilePath; iy$]9Wf6=@
} ) 3YE$,
P.;B V",
[&FMVM`
public void setSFilePath(String value) mhlJzGr*q
{ +hXph
sFilePath = value; zT_{M qY
} -pqShDar|
D"A`b{z
OkzfQ hC}
public String getSFileName() cE]tvL:g
{ #exE~@fy-
return sFileName; {_(;&\5
} MIt\[EB
,dh*GJ{5
00b )Bg
public void setSFileName(String value) A|y&\~<A
{ sF|<m)Kt{W
sFileName = value; zhN'@Wj'_
} Iupk+x>
yRvq3>mU
bd)A6a\h
public int getNSplitter() sBRw#xyS
{ ,HMB`vF
return nSplitter; 4qyL' \d[
} @9vz%1B<l
ej!C^
1Ete;r%5=
public void setNSplitter(int nCount) Pi+,y
{ U4LOe}Ny
nSplitter = nCount; jr!x)yd
} vaK$j!%FE
} +(|T\%$DT
nHT2M{R
vkBngsS
/* dAAE2}e
**Utility.java W"wP%
*/ Keof{>V=CA
package NetFox; v5<Ext rV
vhhsOga
uOW9FAW
public class Utility { umls=iz
_/MKU!\l
`7N[rs9|S
public Utility() C@Wm+E~;8
{ Q>Q$BCD5
oPWvZI(\&
.[O*bk
} T+2?u.{I
*5|\if\
//线程睡眠 #Va@4<4r
public static void sleep(int nSecond) mH}AVje{ `
{ WVwNjQ2PM
try{ 0c:CA>F
Thread.sleep(nSecond); -?e~S\JH
} roRZE[ya
catch(Exception e) o'D6lkf0
{ q)!{oi{x(
e.printStackTrace (); Iqo4INGIi
} <ygkK5#q
} k ( R
-M[5K/[
//日志 QiwZk<rb
public static void log(String sMsg) eKLxNw5
{ PU-;Q@< E
System.err.println(sMsg); U15Hq*8Z
} yY,.GzIjCj
YjG0: 9
l<qxr.X
public static void log(int sMsg) ]p#Zdm1EL
{ /wvA]ooT
System.err.println(sMsg); nTYqZlI,
} }-8K*A3
} XPX{c|]>.
IlS{>6
|4-Ey! P
/* ]>`Q"g~0
**TestMethod.java qtgj"4,:`
*/ LW,!B.`@
package NetFox; $wX5`d1
l}<s~ip
N 4,w
public class TestMethod { &|9?B!,`
1` 9/[2z
rVf`wJ6b
public TestMethod() $1UN?(r
{ ///xx/weblogic60b2_win.exe w1s#8:
try{ QR^pu.k@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); GU"MuW`u2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tpCEWdn5
SiteFileFetch fileFetch = new SiteFileFetch(bean); u,'c:RMV
fileFetch.start(); flmcY7ZV
} TYLf..i<
catch(Exception e){e.printStackTrace ();} orL7y&w(v:
kW/ksz0)
ExnszFX*
} vmmu[v
Wje7fv
l sUQ7%f
public static void main(String[] args) 1bvL
{ 9`vse>,-hg
new TestMethod(); 2@A7i<p
} ;N4mR6
} s!UC{)g,
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