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$z
} mS%4gx~~_n
for(int i=0;i<nEndPos.length-1;i++) lb~E0U`\E`
{ MBw-*K'?zB
nEndPos = nStartPos[i+1]; CPviR<ms_
} _1|$P|$P.
nEndPos[nEndPos.length-1] = nFileLength; /L v1$~
} 7I}P*%(f
} #BY`h~&T
``|AgIg
6/tI8H3E
//启动子线程 dE5D3ze
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >xg5z
for(int i=0;i<nStartPos.length;i++) pQWHG#?7
{ #NNewzC<*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NfzF.{nh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^jD1vUL 2:
nStartPos,nEndPos,i); v`DI<Lt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sx 9uV
fileSplitterFetch.start(); A:# k
} =Z,5$6%)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M#,Q ^rH#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); H&4~Uo.5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Rc[0aj:
nEndPos = " + nFileLength); zY=jXa)K~
// fileSplitterFetch[nPos.length-1].start(); A\QJLWBv^$
7:Ztuc]
?=Db@97
//等待子线程结束 o3N]`xD'
//int count = 0; \we\0@v
//是否结束while循环 6f)2F< 7
boolean breakWhile = false; HpW 42
SVWIEH0?
x,8<tSW)Z
while(!bStop) #=,imsW)
{ p_2pU)%
write_nPos(); DWiBG
Utility.sleep(500); L":bI&V?:
breakWhile = true; U|@V 74
TgfrI
Ev9>@~^
for(int i=0;i<nStartPos.length;i++) $uh z
{ izZ=d5+K
if(!fileSplitterFetch.bDownOver) 06mlj6hV
{ 4Ysb5m)u
breakWhile = false; {i [y9
break; OB-Q /?0
} zsXpA0~3s
} ..W-76{
if(breakWhile) #8h;Bj
break; r8/l P}(F
c EnkU]
<a^Oj LLU
//count++; BR5BJX
//if(count>4) LT@OWH
// siteStop(); x/fX`y|(}*
} ;_?MX/w|&
K^[#]+nQ
{+.r5py
System.err.println("文件下载结束！"); Ao9R:|9
} DcD{*t?x
catch(Exception e){e.printStackTrace ();} %O[N}_XHEh
} JXqr3Np1
?> Dtw#}
GqKsK r2%
//获得文件长度 zaimGMJ ,
public long getFileSize() B 0ee?VC
{ Wp0 Dq(
int nFileLength = -1; ]wVk+%e
try{ YT#3n
URL url = new URL(siteInfoBean.getSSiteURL()); aA'TD:&p1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s5&@Cxzl
httpConnection.setRequestProperty("User-Agent","NetFox"); #*%q'gyHT
tY|8s]{2
Nw_@A8-r
int responseCode=httpConnection.getResponseCode(); G}d-(X
if(responseCode>=400) nY%5cJ`"
{ p#P~Q/;
processErrorCode(responseCode); |N/G'>TS
return -2; //-2 represent access is error iq$$+y,
} ,m3e?j@;r
PmpNAVE'
K2)!h.W
String sHeader; iBg3mc@OO
b7`D|7D
u{<"NR h
for(int i=1;;i++) |*5 =_vF
{ G3i !PwW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =+:{P?*}
//Utility.log(in.readLine()); =='Td[
sHeader=httpConnection.getHeaderFieldKey(i); J:*-gwv9*m
if(sHeader!=null) }T2xXbU
{ D;}xr_
if(sHeader.equals("Content-Length")) )!bUR\
{ |SZo' 6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %r\n%$@_
break; 21X`h3+=
} eV^d6T$
} "r4AY
else D/ybFk
break; [lzN !!B!
} H6*^Ga
} H`hnEOyLp
catch(IOException e){e.printStackTrace ();} <xpph t<
catch(Exception e){e.printStackTrace ();} ZUm?*.g\^
\>. LW9
M9\#Aq&\i
Utility.log(nFileLength); }|OaL*|u
'@|_OmcY
1$/MrPT(b
return nFileLength; $@-P5WcRs
} zET^T5>:
3f.b\4 U
f"[J"j8
//保存下载信息（文件指针位置） *D}0[|O
private void write_nPos() f5*k7fg
{ <*ZJaBwWU~
try{ 4rT*tW"U
output = new DataOutputStream(new FileOutputStream(tmpFile)); S^@S%Eg
output.writeInt(nStartPos.length); !^#jwRpeN
for(int i=0;i<nStartPos.length;i++) C@ZK~Y_g
{ 7w:ef0S
// output.writeLong(nPos); .~A*=
output.writeLong(fileSplitterFetch.nStartPos); $,=6[T!z+e
output.writeLong(fileSplitterFetch.nEndPos); SvM6iZ]
} S_MyoXV
output.close(); jd]s<C3o
} "xI"
catch(IOException e){e.printStackTrace ();} aimarU
catch(Exception e){e.printStackTrace ();} 6k{2 +P
} ,_aM`%q?Fj
{'sY|lou
N[]Hc
//读取保存的下载信息（文件指针位置） 1d"Z>k:mn
private void read_nPos() T3UMCqc=
{ zLs|tJOVp
try{ : JzI>/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g6@Fp7T
int nCount = input.readInt(); c .3ZXqpI;
nStartPos = new long[nCount]; G@FI0\t
nEndPos = new long[nCount]; oBQ#eW aY
for(int i=0;i<nStartPos.length;i++) $E<Esf$
{ ZRxZume<f
nStartPos = input.readLong(); 00I}o%akO
nEndPos = input.readLong(); Ars687WB
} F^"_TV0va
input.close(); N7'OPTKt&
} =L%DX#8
catch(IOException e){e.printStackTrace ();} kIw`P[
catch(Exception e){e.printStackTrace ();} )[H{yQ
} OaJB=J%
;AR{@Fu.
~\,w {
private void processErrorCode(int nErrorCode) WV3|?,y]qm
{ F|Mi{5G%
System.err.println("Error Code : " + nErrorCode); ?]fF3SJk
} 2XTPBZNe
qPB8O1fyU
mK+IEZV<3
//停止文件下载 =9oPowq
public void siteStop() 2"|2a@
{ p.ANVA@:
bStop = true; B\J^=W+`
for(int i=0;i<nStartPos.length;i++) 9TF f8'?d
fileSplitterFetch.splitterStop(); _Jwq`]Z
T2}FYVj?!g
S6}@I ,Q
} u p.Q>28r
} )1N 54FNO
//负责部分文件的抓取 'O5'i\uz
**FileSplitterFetch.java RZM"~ 0
*/ }kw/W#)J
package NetFox; QM3,'?ekRH
f|^dD`
5MFxo63
import java.io.*; ,jXM3?>B
import java.net.*; O^/Maa/D1
I1[g&9,
A7(hw~+@
public class FileSplitterFetch extends Thread { u` oq(?|
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6KD `oUx
String sURL; //File URL -':Y\:W
long nStartPos; //File Snippet Start Position Hzrtlet
long nEndPos; //File Snippet End Position ;a-$D]Db
int nThreadID; //Thread's ID +/#Ei'do
boolean bDownOver = false; //Downing is over uOa26kE4
boolean bStop = false; //Stop identical C6O8RHg
FileAccessI fileAccessI = null; //File Access interface z0|&W&&D
O+%WR
K;LZ-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $P1O>x>LIL
{ .(pN5JI*
this.sURL = sURL; Q{k At%
this.nStartPos = nStart; Z%I
this.nEndPos = nEnd; ;'81jbh
nThreadID = id; jTLSdul+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z4&iK)x
} u:aW 8
TCT57P#b
SQeRSz8bK4
public void run() YF+n b.0.
{ `ptj?6N-
while(nStartPos < nEndPos && !bStop) n@ w^V
{ dt~YW
gM [w1^lj
m*$|GW9
try{ ]f]<4HD=i
URL url = new URL(sURL); V5p= mmnA,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :>p8zG
httpConnection.setRequestProperty("User-Agent","NetFox"); h3T9"w[
String sProperty = "bytes="+nStartPos+"-"; 9f\/\L
httpConnection.setRequestProperty("RANGE",sProperty); \rVQQ|l
Utility.log(sProperty); 7' S@3
0afei4i~N
3!5Ur&
InputStream input = httpConnection.getInputStream(); FgLrb#
//logResponseHead(httpConnection); qc#)!
1sPdz L
j5 g# M
byte[] b = new byte[1024]; + >cBVx6
int nRead; )K'N(w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) aZEn6*0B
{ <C9 XX~
nStartPos += fileAccessI.write(b,0,nRead); [F5h
//if(nThreadID == 1) ""s]zNF}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #2`D`>7456
} ~rjTF!
6sa"O89
1heS*Fwn'
Utility.log("Thread " + nThreadID + " is over!"); _ Ro!"YVX
bDownOver = true; w '3#&k+
//nPos = fileAccessI.write (b,0,nRead); gKOOHUCb
} ,;M4jc{
catch(Exception e){e.printStackTrace ();} !"+'A)Nve
} iS5W>1]
} O5H9Y}i]
{QCf}@_]h
z&V+#Ws/
//打印回应的头信息 iD= p\
public void logResponseHead(HttpURLConnection con) >Z1q j>
{ &qS[%K )
for(int i=1;;i++) w`l{LHrR
{ &K/FyY5
String header=con.getHeaderFieldKey(i); \^#~@9
if(header!=null) E9V5$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B75k^ohfj
Utility.log(header+" : "+con.getHeaderField(header)); M)sZSH.<O
else 3pmWDG6L
break; KFa_
} 1xv8gC:6
} `GXkF:f=
?YeWH WM
IF]lHB
public void splitterStop() Cuc$3l(%
{ .rPn5D Y
bStop = true; rpw.]vnn
} ZylJp8U
7OjR._@
+nQw?'9Z
} 8( btZt
z"*/mP2
7z~_/mAI
/* r[?1
**FileAccess.java h[Gg}N!
*//文件访问(定位，写) ^[15&T5
package NetFox; Ew3ibXD
import java.io.*; 8BvonYt=8
M`6y@<
m~uOXb
public class FileAccessI implements Serializable{ P]z[v)}
]jpu,jz:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b~-%c_
RandomAccessFile oSavedFile; <9>vO,n
long nPos; ]:34kE}e5
kp\\"+,VC
t\$U`V)
public FileAccessI() throws IOException R-^96fFBy
{ ![f ![l
this("",0); /t-fjB{=G
} H~ u[3LQz
6=N`wi
w\}?(uO
public FileAccessI(String sName,long nPos) throws IOException >[6{LAe~hp
{ ?bw4~
oSavedFile = new RandomAccessFile(sName,"rw"); KR"M/#
this.nPos = nPos; ~H6r.:]
oSavedFile.seek(nPos); _4cvX
} ){r2T1+-%
kF>o.uSV
>hH0Q5aL
public synchronized int write(byte[] b,int nStart,int nLen) S>.F_Jl
{ 2Hum!p:1
int n = -1; $4MrP$4TI
try{ ~zHg[X*
oSavedFile.write(b,nStart,nLen); >c-fI$]
n = nLen; E\;ikX&1
} +/D>|loRC
catch(IOException e) (RtueEb.~E
{ rWh6RYd<T
e.printStackTrace (); Q?AmOo-a
} N$[$;Fm:
lgpW@g
_bD/D!|
return n; ~afg)[(
} q$G,KRy/
G^"Vo x4
KN"S?i]X
} T;L>P[hNn
hm<}p&!J
N8`?t5
/* Z0De!?ALV\
**SiteInfoBean.java 2DD:~Tbi
*/ R}mn*h6
package NetFox; ^s.V;R
mZIoaF>t
n&MG7`]N
public class SiteInfoBean { e?bYjJq
lcV<MDS
ET];%~ ^
private String sSiteURL; //Site's URL &uUo3qXQ5l
private String sFilePath; //Saved File's Path >yJ9U,Y
private String sFileName; //Saved File's Name dz>;<&2Z
private int nSplitter; //Count of Splited Downloading File a}SdW
.WQ<jZt>
,<DB&&EV8
public SiteInfoBean() (z$r:p
{//nSplitter的缺省值为5 ~ d^<_R
//default value of nSplitter is 5 ;6 +}z~
this("","","",5); .Wi{lt
} 20rkKFk*
{G*A.$-d
ceGa([#!\_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e4FM} z[
{ PM":Vd/
sSiteURL= sURL; )6~1 ^tD
sFilePath = sPath; d3^OEwe
sFileName = sName; rw)kAe31
this.nSplitter = nSpiltter; 0ult7s}
Hqh6:RuL
b%f[p/no
} kX:tc
Hx$c N
9;%CHb&
public String getSSiteURL() *c[2C
{ "!K'A7.^
return sSiteURL; |+ge8uu?C
} <\zCpkZ'B
D}3XFuZs_
6a}"6d/sTL
public void setSSiteURL(String value) $>U# W:
{ 9dh>l!2
sSiteURL = value; `IINq{Zk
} FI8Oz,
A$g+K,.l
G1 o70
public String getSFilePath() ^7]"kg DA
{ fQ>4MKLw=d
return sFilePath; ]aCk_*U
} ~tB;@e
.ut{,(5
j<%])
public void setSFilePath(String value) 2fIRlrA$
{ (eCFWmO
sFilePath = value; HmK*bZ
} %=j3jj[
-VDo[Zy
nxQ?bk}*d
public String getSFileName() vFrt|JC_{
{ mYB`)M*Y
return sFileName; :"0J=>PH:
} b{DiM098
PCc|}*b
=G~~?>=@2
public void setSFileName(String value) zT~B6
{ t<:D@J]a
sFileName = value; #0b&^QL
} b4Y8N"hL%
RnfXN)+P
+kdySWF
public int getNSplitter() 2WM\elnA
{ KRsAv^']
return nSplitter; ,G^[o,hS
} v}J;ZIb
i54md$Q^
^C&+ ~+
public void setNSplitter(int nCount) z41_oG7
{ 7=4A;Ybq
nSplitter = nCount; VVWM9x
} q&'Lbxc>c
} /.5;in
k6IG+:s
E& 36H
/* A CNfS9M_w
**Utility.java 2=PBxDs;
*/ ghk5rl$
package NetFox; NCA{H^CL
@D`zKYwX1
i`%.
public class Utility { ;)DzCc/
!Q-wdzsp?
V9x8R
public Utility() e1 *__'
{ ,$r2gr!_G
)He#K+[}^4
fm1X1T.
} SP 2 8
-7'#2P<)
//线程睡眠 9CUimZ
public static void sleep(int nSecond) IN^9uL]B
{ 4lc)&
try{ KGZ?b2N?Va
Thread.sleep(nSecond); _J?SIm
} zW{ 6Eg
catch(Exception e) ;'RFo?u K
{ yt.c5>B^
e.printStackTrace (); VmQh$&h
} @kngI7=E
} 1TqF6`;+
P`s(kIe
//日志 !>;w!^U
public static void log(String sMsg) %|3e.1oX
{ }IUP5O6
System.err.println(sMsg); <z#BsnjW{
} Zcd7*EBdx
67<CbQZoN3
&B-[oqC?
public static void log(int sMsg) /rF8@l
{ &jts:^N>
System.err.println(sMsg); #dJ 2Q_2
} _=`x])mM
} o0;7b>Tv
Pw}_[[>$
9rj('F&1
/* =xEk7'W6k
**TestMethod.java cV$lobqO
*/ L@|#Bbmx
package NetFox; y{rn-?`{
C@dGWAG
F%6*Df;cSe
public class TestMethod { #0MK(Ut/
`6 Y33bQ
xcSR{IZ
public TestMethod() >7-y#SkXdo
{ ///xx/weblogic60b2_win.exe SR*Gqx
try{ 9$tl00
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N2~$rpU3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =Q?f96T
SiteFileFetch fileFetch = new SiteFileFetch(bean); |1V2tx
fileFetch.start(); X7cWgo66T
} *8!w&ME+.
catch(Exception e){e.printStackTrace ();} A|vP$zy
_%IqjJO{=r
;e;\q;GP
} >_Uj?F:
k8&FDz
Fe="EDh
public static void main(String[] args) ?R?Grw)`H
{ 7~.ZE
new TestMethod(); {;RF
} ^tE_LL+ji|
} 8$ DwpJ
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