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)); nt:ZO,C:R
} :3N6Ej
for(int i=0;i<nEndPos.length-1;i++) VwN=AFk Oj
{ \h>6k
nEndPos = nStartPos[i+1]; 1y3)ogL
} n\GN}?4
nEndPos[nEndPos.length-1] = nFileLength; x)R1aq
} ?`= <*{_o
} ~%eZQgqA*
c( _R xLJ
:W.pD:/=v
//启动子线程 uK%0,!q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?%cZO"
for(int i=0;i<nStartPos.length;i++) g& ou[_A
{ /Qu<>#[?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L,yq'>*5s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5{gv\S1
nStartPos,nEndPos,i); }wB!Bx2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \zh`z/=92
fileSplitterFetch.start(); :]JMsa6
} )Vz=:.D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3qQ}U}-;|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g#Z7ReMw
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =qvn?I^/
nEndPos = " + nFileLength); <S^Hy&MD>
// fileSplitterFetch[nPos.length-1].start(); ux8K$$$
o)wOXF
1@t8i?:h
//等待子线程结束 v4]#Nc$~T
//int count = 0; ),>whCtsI
//是否结束while循环 wwNkJ+
boolean breakWhile = false; }ssP%c]
W K(GR\@
00LL&ot
while(!bStop) tUksIUYD\
{ Cp?6vu|RA
write_nPos(); >u\'k+=
Utility.sleep(500); \WqC^Di
breakWhile = true; x"7PnN|~
B?db`/G9
aECpe'!m4
for(int i=0;i<nStartPos.length;i++) ]k$:sX
{ qgs:9V xF
if(!fileSplitterFetch.bDownOver) $azK M,<q
{ EK Ac>g
breakWhile = false; \'r;1W
break; %+((F+[
} 3, 3n
} 0h kZ
if(breakWhile) 9!PM1<p
break; l1.eAs5U
\qDY0hIv t
Mr*CJgy
//count++; r]'[qaP
//if(count>4) ]5Q)mWF
// siteStop(); CD. XZA[
} wHZ(=z/q
kT%m`
fo=@ X>S
System.err.println("文件下载结束！"); pxI[/vS N
} BM9:|}\J65
catch(Exception e){e.printStackTrace ();} .]0:`Y,;
} *x)u9rO]
dP<i/@21Wm
8PqlbLo1
//获得文件长度 jgqeDl\=+
public long getFileSize() hXD`OlX
{ vl!o^_70(
int nFileLength = -1; 9&HaEAme
try{ C,8@V`
URL url = new URL(siteInfoBean.getSSiteURL()); [B^V{nUBc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cpH*!*S
httpConnection.setRequestProperty("User-Agent","NetFox"); M=fhRCUB
('`mPD,
kaRjv
int responseCode=httpConnection.getResponseCode(); *c(J4
if(responseCode>=400) s]HJcgI
{ Gx|/ Jq
processErrorCode(responseCode); #4AqWyp#f
return -2; //-2 represent access is error ivSpi?
} ?btX&:j2P
ti<;>P[4
qU,u(El
String sHeader; sYb(g'W*'
+ %07J6
-V)DKf"f
for(int i=1;;i++) Ox1#}7`0>
{ 'rQ>Z A_8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J-g<-!>RM
//Utility.log(in.readLine()); P>3 ;M'KsO
sHeader=httpConnection.getHeaderFieldKey(i); 2bk~6Osp
if(sHeader!=null) b$:<T7vei
{ Q)s[ls
if(sHeader.equals("Content-Length")) 8/dx)*JCq
{ |[}!E/7>b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0xYPK7a=L\
break; X]OVc<F
} Akbt%&
} 3B5GsI
else ]hL`HP
break; [_h/DhC:+
} +bw>9VmG
} _c4kj
catch(IOException e){e.printStackTrace ();} 3b2[i,m<L
catch(Exception e){e.printStackTrace ();} Gd8FXk,.!
Z4 +6'
j:;[Y`2
Utility.log(nFileLength); YxUC.2V|7$
U- UD27
;5bzXW#U
return nFileLength; %|:Gn)8
} 5QR=$?K
Pu=,L#+FN
qQu}4Ye>
//保存下载信息（文件指针位置） M(alc9tn
private void write_nPos() <n)J~B^
{ `H.~#$
try{ c05kHB$O
output = new DataOutputStream(new FileOutputStream(tmpFile)); TM1isZ
output.writeInt(nStartPos.length); +;P8QZK6
for(int i=0;i<nStartPos.length;i++) 7)`U%}R
{ SCCBTpmf2B
// output.writeLong(nPos); vjcG F'-
output.writeLong(fileSplitterFetch.nStartPos); G98P<cyD
output.writeLong(fileSplitterFetch.nEndPos); I$Bu6x!
} CHeU?NtFps
output.close(); n\v;4ly^
} c&{1Z&Y
catch(IOException e){e.printStackTrace ();} S4m??B
catch(Exception e){e.printStackTrace ();} !y&uK&1
} &o$z[b
G^`IfF-j
5,I|beM
//读取保存的下载信息（文件指针位置） p5C:MA~*
private void read_nPos() LyaFWx
{ H\Y5Fd9)
try{ csceu+IA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X0\2qD
int nCount = input.readInt(); 4&}V3"lg
nStartPos = new long[nCount]; ^usZ&9"@P
nEndPos = new long[nCount]; CEwMPPYnD
for(int i=0;i<nStartPos.length;i++) A{[joo
{ TN xl?5:
nStartPos = input.readLong(); TY(B]Q_o
nEndPos = input.readLong(); F3-<F_4.w
} MM}lW-q;
input.close(); 1G0U}-6RH
} ,N[N;Uoj
catch(IOException e){e.printStackTrace ();} qqL :#]lV5
catch(Exception e){e.printStackTrace ();} yqEX0|V%
} 6zo'w Wc3
ewo]-BQS
O%g Q
private void processErrorCode(int nErrorCode) laRcEXj
{ WR&>AOWAD
System.err.println("Error Code : " + nErrorCode); qc(R /[
} -C]k YQ
S}O>@%
BHVC&F*>
//停止文件下载 ))/NGa
public void siteStop() Q]JWWKt6rV
{ 4LEWOWF}
bStop = true; kPhdfF*Q
for(int i=0;i<nStartPos.length;i++) )\S3Q
fileSplitterFetch.splitterStop(); I~^t\iujs
\kDQ[4mGq
?QDHEC62
} ans(^Up$
} 50s1o{xwc
//负责部分文件的抓取 Re=()M
**FileSplitterFetch.java S:bYeD4
*/ jR1o<]?
package NetFox; ?/M:
X#ZQpo'h
hTEwp.
import java.io.*; SmpYH@
import java.net.*; J?wCqA
D*%?0
fH@P&SX
public class FileSplitterFetch extends Thread { syJLcK+e
W)_|jpd[
R]h3a:ic
String sURL; //File URL =JkPE2mU
long nStartPos; //File Snippet Start Position ?*zDsQ
long nEndPos; //File Snippet End Position ~'9\y"N1
int nThreadID; //Thread's ID :17Pc\:DS
boolean bDownOver = false; //Downing is over oe'f?IY
boolean bStop = false; //Stop identical ){nOM$W
FileAccessI fileAccessI = null; //File Access interface {\WRW}iO
]c9\[Kdq}H
u?-|sv*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jIL+^{K<
{ khc1<BBsT
this.sURL = sURL; W?F Q
this.nStartPos = nStart; 22T\-g{
this.nEndPos = nEnd; ;p(I0X
nThreadID = id; 2zV{I*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |JL?"cc
} y}F;~H~P
YYN'LF#j
H|IG"JB
public void run() o"V+W
{ Ol sX
while(nStartPos < nEndPos && !bStop) /h7uE
{ %/4_|.8u
2dyS_2u
EY`]""~8v
try{ 4 Aj<k
URL url = new URL(sURL); `53S[8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T,oZaJ<
httpConnection.setRequestProperty("User-Agent","NetFox"); U*:ju+)k
String sProperty = "bytes="+nStartPos+"-"; 5SMV3~*P
httpConnection.setRequestProperty("RANGE",sProperty); U2Tw_
Utility.log(sProperty); [v+5|twxpU
3#0y.. F
3xz|d`A
InputStream input = httpConnection.getInputStream(); .k-t5d
//logResponseHead(httpConnection); '~9w<dSB!r
wVq9t|V
=.qX u+
byte[] b = new byte[1024]; @#p6C
int nRead; xi<yB0MoA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l>?f+70
{ QHr'r/0
nStartPos += fileAccessI.write(b,0,nRead); ~: fSD0
//if(nThreadID == 1) @6 a'p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nMJ(tQ
} k. NJ+
UcKVLzKs
[1Aoj|
Utility.log("Thread " + nThreadID + " is over!"); gBO,
bDownOver = true; (hBph+
//nPos = fileAccessI.write (b,0,nRead); #+N_wIP4
} A>8~deZ9
catch(Exception e){e.printStackTrace ();} }[=)sb_
} '1rGsfp6In
} 1G6 \}El95
+w7U7" xQ
l^^Z}3^Rk
//打印回应的头信息 )Ii`/I^
public void logResponseHead(HttpURLConnection con) .^2.h
{ Uq @].3nf
for(int i=1;;i++) TNckyP75u
{ +_{cq@c
String header=con.getHeaderFieldKey(i); 3:G$Y:#P
if(header!=null) _^eiN'B
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $e2+O\.>
Utility.log(header+" : "+con.getHeaderField(header)); 4x<H=CJC
else 5 1N/XEk
break; &Nh zEl1
} 1V9AnzwX
} 5rfDm
en/h`h]h
?PS?_+E\L
public void splitterStop() pY[b[ezb
{ $P#x>#+[A
bStop = true; _BY+Tfol
} vQp'bRR
'sXrtl7{^
@/?i|!6
} "dGN0i
YK[2KTlo
#t;]s<
/* XI|k,Ko<
**FileAccess.java !*L)v
*//文件访问(定位，写) 0%< hj
package NetFox; _3D9>8tzE7
import java.io.*; @87Y/_l
9l"=]7~%
\+nV~Pi"A
public class FileAccessI implements Serializable{ mj?Gc
0;@>jo6,!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vK@UK"m
RandomAccessFile oSavedFile; VBix8|
long nPos; ~c<8;,cjYR
|U;O HS
6WT3-@d
public FileAccessI() throws IOException 7M4J{}9
{ B @QWr;
this("",0); 9unRMvE u
} Pzq^x]
1KrJS(.
qbD 7\%
public FileAccessI(String sName,long nPos) throws IOException gSw4\R
{ lct
oSavedFile = new RandomAccessFile(sName,"rw"); O1c:X7lHc
this.nPos = nPos; Ky"FL
oSavedFile.seek(nPos); >V?0#f45@
} J,)ytw]
~G@YA8}
?RS:I%bL
public synchronized int write(byte[] b,int nStart,int nLen) s5{=lP
{ >h\u[I$7
int n = -1; 1s@QsZ3
try{ RC[Sa wA
oSavedFile.write(b,nStart,nLen); ZSK_Lux>
n = nLen; ObEz0Rj
} G\BZ^SwE
catch(IOException e) `j@1]%&z
{ Ms,MXJtH
e.printStackTrace (); ws5Ue4g|
} cZ?$_;=
P9'` 2c
Uzzm2OS`
return n; )Ln".Bu,
} YIg43Av
Wj^e)2%
9/29>K_
} D)ri_w!Q
zaHZ5%{LQD
lP`BKc,
/* =/46;844T
**SiteInfoBean.java .>F4s_6l
*/ )S%t)}
package NetFox; E3O^Tg?j
/m"/#; ^l
lJ-PW\P
public class SiteInfoBean { 3r kcIVO
k*fU:q1
Xj/z),
private String sSiteURL; //Site's URL !Yb !Au[
private String sFilePath; //Saved File's Path 8^ f:-5
private String sFileName; //Saved File's Name WV$CZgL
private int nSplitter; //Count of Splited Downloading File 1Y'4 g3T
K#wA ;
D1xGUz2r
public SiteInfoBean() W]ca~%r
{//nSplitter的缺省值为5 E^F<"mL*
//default value of nSplitter is 5 #mu L-V
this("","","",5); U*$P"sS`
} qXW\/NT"p<
B{j><uxl
f+ceL'fr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +`Z1L\gmA
{ El<*)
sSiteURL= sURL; |g3:+&
sFilePath = sPath; v&YeQC>
sFileName = sName; 4$&l`yWU+
this.nSplitter = nSpiltter; RtMI[
ZiJF.(JS
QE(.w dHP
} ResU5Ce~
4@?0wV
\tI%[g1M
public String getSSiteURL() uPz+*4+
{ ! dzgi:
return sSiteURL; z5fE<=<X_W
} &ry*~"xoh
c 3QgX4vq
nTqU~'d'
public void setSSiteURL(String value) !,[#,oy;
{ Wm}c-GD
sSiteURL = value; %PYl
} q`<:CfCt
.zO2g8(VR
A#"Wk]jX
public String getSFilePath() ,5n!a.T
{ Lj1l]OD
return sFilePath; 3^o(\=-JX
} v03cQw\"WE
!!1?2ine
*DF3juf~
public void setSFilePath(String value) )5Khl"6!z
{ JY0aE
sFilePath = value; pr0X7 #_E5
} Yr9'2.%Q
&bsq;)wzs
~R!1{8HP
public String getSFileName() *r`=hNr
{ i1 E|lp)
return sFileName; )/;KxaKt
} T`bYidA
&GP(yj]
pp"X0
public void setSFileName(String value) AWR :~{
{ 8MJJ w;
sFileName = value; cbzA`b'Mg
} <XdnVe1
zKQ<Zr
|p|Zv H
public int getNSplitter() -H-U8/WC
{ iiPVqU%
return nSplitter; 1V%tev9a
} 5 D|#l*V
#dauXUKH
k%.v`H!
public void setNSplitter(int nCount) %F*9D3^h
{ LE\*33k_
nSplitter = nCount; jl,gqMn"V
} B"^j>SF
} voa)V1A/]
Y)rK'OY'
5nG\J g7
/* PUdv1__C
**Utility.java ?WI v4
*/ tr0b#4
package NetFox; VI! \+A
>^Nnhnr
D;,p?]mgO~
public class Utility { *6s_7{;
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(m/:B=K
public Utility() 6#Vl3o(E|
{ oC&}lp)q
;z:Rj}l
b_x!m{
} e@'x7Zzh
mv9D{_,pD
//线程睡眠 E>fY,*0
public static void sleep(int nSecond) ^ D0"m>3r
{ HhbBt'fH
try{ [L%Ltmx
Thread.sleep(nSecond); }<Ydj .85
} WIWo4[(
catch(Exception e) m#+0m!
{ EjPR+m
e.printStackTrace (); rZUTBLZ`j
} dDcQSshL
} X@~/.H5
m(f`=+lqI`
//日志 htB2?%S=T
public static void log(String sMsg) 1j2U,_-
{ O"\4[HE^
System.err.println(sMsg); igu1s}F
} <"Y>|X
B>u`%Ry&
w,1N ;R&
public static void log(int sMsg) ;MfqI/B{
{ ,2AulX1
System.err.println(sMsg); FK BRJ5O
} N XB8u6
} CI*JedO]
~&:-c v
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/* ?>7\L'n=5I
**TestMethod.java dV$[O`F*b
*/ ET[5`z
package NetFox; sI\NX$M
-zECxHjx
P$'PB*5d|
public class TestMethod { gwB,*.z
}P.s
.XgY&5Qk
public TestMethod() Y6wr}U
{ ///xx/weblogic60b2_win.exe QFTiE1mGH
try{ .BxI~d^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,u@:(G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W~H`{x%Av>
SiteFileFetch fileFetch = new SiteFileFetch(bean); p;4FZ$
fileFetch.start(); +.djC3^:
} K^x{rn.Zf
catch(Exception e){e.printStackTrace ();} ;)ay uS sQ
dpz@T>MS=
)EMlGM'2q
} f['I4 /o
@ws&W=NQ
xkf2;
public static void main(String[] args) $\/i t
{ t<Sa;[+
new TestMethod(); '(iPI
} ~_BjcY
} 0%xb):Ctw
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