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)); 9.>he+
} 4Ai#$SHLm
for(int i=0;i<nEndPos.length-1;i++) >Q#\X=a>
{ zvOSQxGQ
nEndPos = nStartPos[i+1]; +'V ,z
} ]@A31P4t|
nEndPos[nEndPos.length-1] = nFileLength; }cO}H2m
} kO}QOL4
} |%$mN{
jI!WE$dt
}AGdWt@
//启动子线程 Q@ghQGn#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -izZ D
for(int i=0;i<nStartPos.length;i++) VMl)_M:'
{ ]I:h4hgw
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0eFvcH:qG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M _e^KF
nStartPos,nEndPos,i); !n3J6%b9y/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FA$1&Fu3Y
fileSplitterFetch.start(); 2)T.Ci cx
} W.m2`] &
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M32Z3<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l<-0@(x)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ov|/=bzro
nEndPos = " + nFileLength); ~{$5JIpCm
// fileSplitterFetch[nPos.length-1].start(); }J+\o~
cyXnZs ?|
OM (D@up
//等待子线程结束 snvixbN
//int count = 0; |PutTcjQ
//是否结束while循环 ><w=
boolean breakWhile = false; cz;gz4d8
T:0#se
F.$NYr/|y
while(!bStop) cr>"LAi
{ R4AKp1Y
write_nPos(); &O\$=&, h
Utility.sleep(500); JW9U&Bj{
breakWhile = true; h e1=
$;X3h
8/T,.<5
for(int i=0;i<nStartPos.length;i++) l'FNp
{ M]uO%2
if(!fileSplitterFetch.bDownOver) j-(k`w\
{ zC|y"PTw
breakWhile = false; ;t5e]
break; !cA4erBP
} xC YL3hl
} k|;[)gE
if(breakWhile) 8omk4 ;
break; us>$f20T
{wCzm
cUD}SOW
//count++; ";*Iwd*V
//if(count>4) 'D[g{LkL
// siteStop(); CAtdx!
} TKrh3
Hq."_i{I
-iySU 6
System.err.println("文件下载结束！"); &k@r23V7r
} |yYu!+U
catch(Exception e){e.printStackTrace ();} &-2i+KjEX
} lQl
&\ $x.!
*Ry{}|_8
//获得文件长度 jQi)pVT^
public long getFileSize() W8Aii'Q8C/
{ wJ>2}
int nFileLength = -1; Hmv@7$9s\
try{ ~]C m
URL url = new URL(siteInfoBean.getSSiteURL()); <}t<A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H-'~c\)
httpConnection.setRequestProperty("User-Agent","NetFox"); BjAmM*k
b^C2<'
'G8.)eTA'
int responseCode=httpConnection.getResponseCode(); cRS2v--\-
if(responseCode>=400) B^lm'/,@
{ (C60HbL
processErrorCode(responseCode); eG\`SKx_
return -2; //-2 represent access is error 9xM7X?
} ctT6va
pHv~^L%=
N3?@CM^hHw
String sHeader; '/~j!H4q9
m\;@~o'k
vj4n=F,Z
for(int i=1;;i++) Qv/Kbw N{
{ ,-.a! a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ';Ew-u
//Utility.log(in.readLine()); (f>~+-IL
sHeader=httpConnection.getHeaderFieldKey(i); qb?9i-(
if(sHeader!=null) Ai5|N
{ d,*#yzO
if(sHeader.equals("Content-Length")) L_QJS2
{ Av"^uevfs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $Y&rci]
break; ht5eb"c+8
} (^;Fyf/
} cUK9EOPe
else L>{p>
break; e sDd>W
} 2-x#|9
} 0pl |
catch(IOException e){e.printStackTrace ();} OM 4,Sevk
catch(Exception e){e.printStackTrace ();} ~CQTPR
>Z&Y!w'A|u
*\T ]Z&E"
Utility.log(nFileLength); 1Aw/-FxJ
#azD&6`
jw$[b=sa
return nFileLength; w//L2.
} 1k?k{Ri
tC4 7P[b
a@}A;y'd
//保存下载信息（文件指针位置） a[A9(Ftn
private void write_nPos() Y=YIz>u
{ -9> oB
try{ 8}<4f|?
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y!nxHRE
output.writeInt(nStartPos.length); ! C|VX,w
for(int i=0;i<nStartPos.length;i++) gy6Pf4Yo
{ t-3y`31i.
// output.writeLong(nPos); k.("<)
output.writeLong(fileSplitterFetch.nStartPos); *9I/h~I
output.writeLong(fileSplitterFetch.nEndPos); fsH=2p
} z-;2)RkV2
output.close(); kCVA~%d7
} <yz&> +9,
catch(IOException e){e.printStackTrace ();} jk-e/C
catch(Exception e){e.printStackTrace ();} CF_pIfbaf
} ncCgc5uP
OjRJyhzS*
Fg<rz&MR
//读取保存的下载信息（文件指针位置） UqEpeLK
private void read_nPos() :qL1jnR^
{ _pe_w{V-b6
try{ +*vg)F:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XLxr@1
int nCount = input.readInt(); +`s%-}-r
nStartPos = new long[nCount]; <Zn-P
nEndPos = new long[nCount]; Qkq9oZ
for(int i=0;i<nStartPos.length;i++) 41Htsj
{ mZ^ev;
nStartPos = input.readLong(); WZ]f \S
nEndPos = input.readLong(); dzn[4
} C=uYX"
input.close(); UthH
} 'I8K1Q=/
catch(IOException e){e.printStackTrace ();} f!n0kXVu6U
catch(Exception e){e.printStackTrace ();} '&n4W7
} r[Zg$CW
w!N?:}P<N
M9scZuj
private void processErrorCode(int nErrorCode) WjVj@oC
{ mf\eg`'4?
System.err.println("Error Code : " + nErrorCode); GfMCHs
} H(WRm1i"G
daakawn+
TE!+G\@
//停止文件下载 PGaYYc3X
public void siteStop() ::eYd23
{ : ZWKrnG
bStop = true; cTQ]0<9:e
for(int i=0;i<nStartPos.length;i++) \WN,.
fileSplitterFetch.splitterStop(); GoTJm}[NP
QFYO_$1Y)
x{.+i'
} n13#}i{tm
} "x P2GZ
//负责部分文件的抓取 F:B8J4/
**FileSplitterFetch.java P/hV{@x
*/ -=)Al^V4T
package NetFox; qPI1\!z6
h.ln%6:d
[;n/|/m,
import java.io.*; r(Vz(
import java.net.*; (yB)rBh>n
xG|T_|?
J jp)%c#_
public class FileSplitterFetch extends Thread { A;\1`_i0
quGvq"Y>
4' MmT'
String sURL; //File URL -xk.wWpV
long nStartPos; //File Snippet Start Position SWpvbs.'so
long nEndPos; //File Snippet End Position CW)JS3}W"
int nThreadID; //Thread's ID ?!Bf# "TY
boolean bDownOver = false; //Downing is over 5gZ6H/.
boolean bStop = false; //Stop identical ]:X# w0UR
FileAccessI fileAccessI = null; //File Access interface <*'%Xgm
IqW4Q1>f
*~>}*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zA g.,dA
{ dr~6}S#
this.sURL = sURL; 9z0G0QW[
this.nStartPos = nStart; ~aZy52H_#.
this.nEndPos = nEnd; ooW;s<6
nThreadID = id; h]{V/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `z)q/;}fC
} ZD(VH6<g%
k(bDj[0q^
psaPrE
public void run() 0!fT:Ra
{ 1;8%\r[|5^
while(nStartPos < nEndPos && !bStop) 2b i:Q9
{ l}jC$B`5
K\3N_ztu
PDi]zp9>H
try{ tzn+ M0'
URL url = new URL(sURL); lH#C:n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `EJ.L6j$'
httpConnection.setRequestProperty("User-Agent","NetFox"); .4&pi
String sProperty = "bytes="+nStartPos+"-"; ^ b`wf"A
httpConnection.setRequestProperty("RANGE",sProperty); %/:0x:ns
Utility.log(sProperty); }\$CU N
BD.>aAi!
b$W~w*O
InputStream input = httpConnection.getInputStream(); Wp2$L-T&$
//logResponseHead(httpConnection); Nm.G,6<J
yPXa
c`E0sgp
byte[] b = new byte[1024]; aB*'DDlx"r
int nRead; wdo(K.m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w28&qNha
{ mY1Gm|
nStartPos += fileAccessI.write(b,0,nRead); ]o<&Q52|
//if(nThreadID == 1) `:>N.9'o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |mp~d<&
} 3Ud{W$Ym
gx ]5)O
Krw'|<
Utility.log("Thread " + nThreadID + " is over!"); <<M1:1
bDownOver = true; LyuA("xB#
//nPos = fileAccessI.write (b,0,nRead); &`^PO$
} FD[o94`%
catch(Exception e){e.printStackTrace ();} 3"O&IY<
} L}M%z9K`h
} lh`ZEvt
nQaryL
ZR8%h<
//打印回应的头信息 q*'-G]tH=
public void logResponseHead(HttpURLConnection con) kE`Fg(M
{ 8W"Xdv{
for(int i=1;;i++) \WPy9kRU
{ gCL?{oVU
String header=con.getHeaderFieldKey(i); `37%|e3bQ
if(header!=null) B{hV|2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4o69t
Utility.log(header+" : "+con.getHeaderField(header)); s^R$u"pFs
else jb83Y>
break; K3.z>.F'h
} k@ So l6
} C-sFTf7
~oX`Gih
U)6Ew4uRxV
public void splitterStop() \ !qe@h<
{ $g&_7SJ@
bStop = true; #DA,*
} K +l-A>Ic
U9Gg#M4tY
vtw97G
} ecMpU8}rR
@*&`1
!%/2^
/* .Mxt F\
**FileAccess.java 49tJ+J-N
*//文件访问(定位，写) A)80qx:
package NetFox; Uo0[ZsFD
import java.io.*; =:=s
sUk&NM%>
XYze*8xUb
public class FileAccessI implements Serializable{ j*_>/gi
q"-+`;^7(-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U]PsL3:
RandomAccessFile oSavedFile; kIJ=]wU|v
long nPos; #:E^($v
_Rk>yJD7s
Ch'e'EmI
public FileAccessI() throws IOException ]vjMfT%]W
{ 4&<zkAMR
this("",0); (vPE?^}b
} z0 J:"M
FvyC$vip
P/[}$(&:
public FileAccessI(String sName,long nPos) throws IOException xA>3]<O
{ ;%mdSaf
oSavedFile = new RandomAccessFile(sName,"rw"); }*|aVBvU
this.nPos = nPos; ZK`x(h{p)
oSavedFile.seek(nPos); )&[Zw{6P
} wpf
`,s0^?_
#&Fd16ov
public synchronized int write(byte[] b,int nStart,int nLen) T~naAP
{ Z|BOuB^
int n = -1; 9Idgib&
try{ 5|g#>sx>`q
oSavedFile.write(b,nStart,nLen); `^: v+!
n = nLen; F> b<t.yV
} *fp4u_:`
catch(IOException e) tN_~zP
{ "u3 N9
e.printStackTrace (); M5`wfF,j
} iUk#0 I
"Xj>dB1~
*n`8 -=
return n; CA3`Ee+rD
} 6#Bg99c
uiq;{!dop
v03^
} w-5_Ru
cHUj6'neO
&t@|/~%[
/* t<yOTVah
**SiteInfoBean.java 6Z!OD(/e
*/ rp!>rM] s
package NetFox; V&R_A~<T
fvM|Jb
vqRW^>~-B
public class SiteInfoBean { e$4l[&kH_
g.x]x#BC
RQCKH]&!
private String sSiteURL; //Site's URL |$`I1
private String sFilePath; //Saved File's Path | (: PX
private String sFileName; //Saved File's Name ,,~|o3cfq
private int nSplitter; //Count of Splited Downloading File Zrp9`~_g<!
E|ZLz~
%5/h;4
public SiteInfoBean() p2j=73$
{//nSplitter的缺省值为5 jEW@~e
//default value of nSplitter is 5 qViolmDz
this("","","",5); to3D#9Ep
} c59l/qoz
d~w}{LR[1
/;9]LC.g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =Cp}iM
{ F2CoXe7
sSiteURL= sURL; NplkhgSj
sFilePath = sPath; $-lP"m@}
sFileName = sName; +"D*0gYD
this.nSplitter = nSpiltter; sRSy++FRF
Q);^gV
/Avl&Rd
} E{E%nXR)
:\,3=suWq
X-J<gI(Y
public String getSSiteURL() Ng1uJa[k!d
{ XkuZ2(
return sSiteURL; yWZ%|K~$
} >@StKj
X]v.Yk=wu
k?ksv+e\
public void setSSiteURL(String value) KHt.g`1:R
{ (C!33s1
sSiteURL = value; /@f3|L<1@V
} ]z5gC`E0
Hv<jf38
"~aCW~
public String getSFilePath() ^r0mx{i&
{ 9 e0Oj3!B
return sFilePath; ompkDl\E
} jl~?I*Gr
&ajpD sz;
zIgD R
public void setSFilePath(String value) a%)-iL X8&
{ |T^c(RpOE
sFilePath = value; *8j2iu-|
} P]||Xbbp
l/@t>%
Zv)x-48
public String getSFileName() 8Qi@z Jq,
{ x@480r
return sFileName; ]BBL=$*
} \D,c*I|p7
d`&F
,MdK "Qa>
public void setSFileName(String value) ET}Dh3A
{ Irnfr\l.
sFileName = value; i-_ * 5%A
} _T[m YY
( mKuFz7
4]3(Vyh`
public int getNSplitter() 0s8w)%4$
{ ZdY)&LJ
return nSplitter; "Rv],O"
} "1Oe bo2
#OVf2 "
::A]p@
public void setNSplitter(int nCount) l:H}Y3_I
{ U#U nM,3%
nSplitter = nCount; 298@&_
} uGMmS9v$ J
} BV01&.<|
QL_9a,R'r
O6$d@r;EK]
/* NM_Xy<.~E
**Utility.java l gzA) (
*/ p2:>m\
package NetFox; `@07n]KB
#0;ULZ99aH
k(.6K[b
public class Utility { dCkk5&2n
PhOtSml0
y,QJy=?
public Utility() :gJ?3LwTf
{ I@<\DltPi
/"%(i#<)xs
"`4V^1
} bI"_hvcFp
\tx4bV#
//线程睡眠 3/q)%Z^=
public static void sleep(int nSecond) QBI;aG<+b>
{ ,aBo p#
try{ >=Pn\"j
Thread.sleep(nSecond); :v>Nz7SB
} t}]R0O.s
catch(Exception e) qoXncdDHZ
{ ^yo~C3r~
e.printStackTrace (); >MeM
} n6Qsug$z
} #[C=LGi
_rU%DL?
//日志 1SGLA"r
public static void log(String sMsg) x<es1A'u6
{ F+3}Gkn
System.err.println(sMsg); Lradyo44u\
} .sOEqwO}>
c/Ykk7T9--
2)zAX"#/
public static void log(int sMsg) C>:'@o Z
{ b,Vg3BS
System.err.println(sMsg); m<X[s
} @ysc?4% q
} /:OSql5K*<
Z.DO 2=+=
TppuEC>
/* fT.GYvt`
**TestMethod.java ]'iOV-2^'
*/ exHg<18WSe
package NetFox; y]e[fZ`L
R]! [h
-)p S\$GC
public class TestMethod { L H8iHB
;0c -+,
[,)G\
public TestMethod() V|n}v?f_q
{ ///xx/weblogic60b2_win.exe |r%NMw #y
try{ t0*,%ge:<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Oe["4C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %7y8a`}
SiteFileFetch fileFetch = new SiteFileFetch(bean); zG. \xmp
fileFetch.start(); /)<x<7FKW
} ym=7EY?o
catch(Exception e){e.printStackTrace ();} &xYO6_.
#NZ#G~oeO
^.|P&f~
} "h'+!2mf
w4fz!l]
P<5v\\
public static void main(String[] args) `UK'IN.il
{ ]9P2v X
new TestMethod(); z?DI4O#Up
} ^.HvuG},O
} OkV*,n
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