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)); '3Lu_]I-
} OQ7 `n<I<)
for(int i=0;i<nEndPos.length-1;i++) .w;kB}$YC
{ pF4Z4?W
nEndPos = nStartPos[i+1]; u8]FJQ*\6+
} h693TS_N
nEndPos[nEndPos.length-1] = nFileLength; ==& y9e
} 2ozh!8aL
} %IX)+ Lp`
6,aH[>W
xC,x_:R`
//启动子线程 ~Ix2O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'gvR?[!t
for(int i=0;i<nStartPos.length;i++) X!p`|i
{ ocFk#FW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Aeb(b+=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XzHR^^;u"*
nStartPos,nEndPos,i); b:D92pH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S0)JIrrHC
fileSplitterFetch.start(); &CQO+Yr$l
} z@i4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -}9^$}PR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *y!O\-\S#>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", })H d]a
nEndPos = " + nFileLength); !:^q_q4
// fileSplitterFetch[nPos.length-1].start(); %'yrIR
<;6{R#Tuh
"FWx;65CR
//等待子线程结束 ,|{`(y/v
//int count = 0; /{\ /e"5
//是否结束while循环 ,^1zG
boolean breakWhile = false; mK[Z#obc=
RZzHlZ
n7cy[%yT
while(!bStop) ch8a
{ n4/Wd?#`
write_nPos(); `8ac;b
Utility.sleep(500); f9W:-00QD
breakWhile = true; kFv*>>X`
Zd6ik&S
P[2!D)A
for(int i=0;i<nStartPos.length;i++) yQiY:SH
{ -GAF>
if(!fileSplitterFetch.bDownOver) c]PTU2BB8
{ lPZ(c%P
breakWhile = false; @kWL "yy,
break; +e-F`k
} x#J9GP.
} 6OAs%QZ
if(breakWhile) #$I@V4O;#
break; WVdV:vJ-
Uj):}xgi'
`m7<_#Y
//count++; "`$,qvNN
//if(count>4) mb1mlsE
// siteStop(); D%p*G5Bg3
} At'CT5=
DB5J3r81
K*SgEkb'l
System.err.println("文件下载结束！"); USVDDqZ
} 1f`De`zXzr
catch(Exception e){e.printStackTrace ();} :A8}x=K
} m2c'r3UEu
@- STo/
qq/>E*~
//获得文件长度 d:@+dS
public long getFileSize() <+_XGOt0<
{ >R+-mP!nj
int nFileLength = -1; X zJ#)}f
try{ {^WK#$]
URL url = new URL(siteInfoBean.getSSiteURL()); @>)VQf8s1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -&Z!b!jN
httpConnection.setRequestProperty("User-Agent","NetFox"); +/~]fI
Xp:A;i9
{]k#=a4
int responseCode=httpConnection.getResponseCode(); }a7d(7
if(responseCode>=400) (/e&m=~
{ f#0HiE!
processErrorCode(responseCode); ]n!V
return -2; //-2 represent access is error #\0m(v
} T/_u;My;
BJj'91B[d
D&G6^ME
String sHeader; E^1yU
rH3U;K!
~"#0rPT
for(int i=1;;i++) *;fTiL
{ i#[8I-OtN/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g8<ODU0[g
//Utility.log(in.readLine()); h>/teHy /
sHeader=httpConnection.getHeaderFieldKey(i); ?UtKu
if(sHeader!=null) A2|Bbqd
{ KD kGQh#9
if(sHeader.equals("Content-Length")) V<QpC5
{ b^/u9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )|~&(+Q?]
break; }r:"X<`
} |_;kQ(,
} >Xn,jMUW
else e~]P _53
break; p&(0e,`z/
} -9b=-K.y
} 1bFZyD"
catch(IOException e){e.printStackTrace ();} \p4*Q}t
catch(Exception e){e.printStackTrace ();} .]v>LsbhF
dn(!wC]
kR<sSLEb
Utility.log(nFileLength); f2WVg;Z
aTvyzr1
C'JI%HnQ
return nFileLength; TO6F
} `<YMkp[
QVT0.GzR
G\sx'#Whc
//保存下载信息（文件指针位置） w <r*&
private void write_nPos() uw+nll*W%
{ >z<L60S
try{ q,P.)\0A
output = new DataOutputStream(new FileOutputStream(tmpFile)); G_F_TNO
output.writeInt(nStartPos.length); *~PB
for(int i=0;i<nStartPos.length;i++) mdc?~??8
{ A;co1,]gR
// output.writeLong(nPos); -H60T,o
output.writeLong(fileSplitterFetch.nStartPos); G*=HjLmZg
output.writeLong(fileSplitterFetch.nEndPos); ]Jswxw
} (HAdr5
output.close(); ygz2bHpD~
} Zux L2W
catch(IOException e){e.printStackTrace ();} ;]LQ}^MP(
catch(Exception e){e.printStackTrace ();} $bE"3/uf
} EXSH{P O+
Ku[q#_7
LphCx6f,X
//读取保存的下载信息（文件指针位置） $<-a>~^Tp
private void read_nPos() OLG)D#m(4/
{ rmjuNy=(
try{ =oSD)z1c?x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +L09^I
int nCount = input.readInt(); Ftyxz&-4$p
nStartPos = new long[nCount]; zZ[kU1Fyv
nEndPos = new long[nCount]; `{#""I^_
for(int i=0;i<nStartPos.length;i++) AF:_&gF
{ L'wR$
nStartPos = input.readLong(); =c6d$
nEndPos = input.readLong(); ^tTM 7
} }9ulHiR
input.close(); \n}%RD-Ce
} ,LBj$U]e|E
catch(IOException e){e.printStackTrace ();} R~=c1bpdq
catch(Exception e){e.printStackTrace ();} z(A60b}
} fHaF9o+/b
(Nzh1ul\}
Ic3a\FTr\
private void processErrorCode(int nErrorCode) ^iH[ 22b4
{ K"l~bFCZ8
System.err.println("Error Code : " + nErrorCode); 4zs0+d+
} $?ss5: S
?8753{wk
%g?M?D8Ud3
//停止文件下载 v}!lx)#
public void siteStop() %RW*gUvc]
{ (\qf>l+*
bStop = true; 5B~]%_gZr
for(int i=0;i<nStartPos.length;i++) ^qL<=UC.
fileSplitterFetch.splitterStop(); <8(q.
BiU>h.4=\(
=bp'5h8_
} l9QIlTc7
} ",~ZO<P
//负责部分文件的抓取 3XY"s"
**FileSplitterFetch.java oyiG04H&
*/ \>\ERVEd
package NetFox; 7b~uU@L`
m2m ;|rr
,tXI*R
import java.io.*; -medD G
import java.net.*; $\m:}\%p
h8WM4 PK
X!V#:2JY
public class FileSplitterFetch extends Thread { GYtgw9 "Y
)-I/ej^
]R~hzo
String sURL; //File URL {JdXn
long nStartPos; //File Snippet Start Position gR/?MJ(v
long nEndPos; //File Snippet End Position 26}3
int nThreadID; //Thread's ID q"269W:
boolean bDownOver = false; //Downing is over |zRrGQYm
boolean bStop = false; //Stop identical BuvnY
FileAccessI fileAccessI = null; //File Access interface ~"*W;|)
~APS_iG[
,OrrGwp&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A#`$#CO
{ e6*,MnqBh
this.sURL = sURL; |Fx *,91
this.nStartPos = nStart; xm=Gt$>.o
this.nEndPos = nEnd; sw9ri}oc
nThreadID = id; 6lpJ+A57#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mdbi@ms@
} BJ_"FG
InL_JobE8r
%4R1rUrgt|
public void run() IPTFx )]G
{ `#ff`j|a
while(nStartPos < nEndPos && !bStop) jBEW("4R
{ GsO(\hR6^
Z6b]EcP)#
D\;5{,:d
try{ g'!"klS93
URL url = new URL(sURL); N*[b26
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XlXt,
httpConnection.setRequestProperty("User-Agent","NetFox"); Pc?"H!Hkn
String sProperty = "bytes="+nStartPos+"-"; t!xdKX& }
httpConnection.setRequestProperty("RANGE",sProperty); 4YY!oDN:
Utility.log(sProperty); CY':'aWfa<
X
Y4N7# 5
InputStream input = httpConnection.getInputStream(); 60n>FQ<
//logResponseHead(httpConnection); 2WLLI8
nWc@ufY
eKuF7Oo
byte[] b = new byte[1024]; 3zmbx~| =\
int nRead; $[Ut])4 ~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .p Mwa
{ :W>PKW`^
nStartPos += fileAccessI.write(b,0,nRead); =i}lh}(
//if(nThreadID == 1) 8,F|*YA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Aua}.Fl,
} GwA\>qXw
CL`+\ .
T++q.oFc
Utility.log("Thread " + nThreadID + " is over!"); '5Kj"aD%
bDownOver = true; /V cbT >=
//nPos = fileAccessI.write (b,0,nRead); 3_9CREZCl
} FzSL[S4i
catch(Exception e){e.printStackTrace ();} Oc,HnyV+
} OVxg9
} 0$b4\.0>~
UlNiH
<5Ll<0
//打印回应的头信息 s1sn,?
public void logResponseHead(HttpURLConnection con) 7}MnvWP
{ ;xUo(^t7>
for(int i=1;;i++) `<P:ly.
{ FjizPg/|!
String header=con.getHeaderFieldKey(i); >S0kiGDV{
if(header!=null) /oJ &\pI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 86cnEj=
Utility.log(header+" : "+con.getHeaderField(header)); L%3Bp/`S
else M/lC&F(
break; @+~>utr
} y$di_)&g
} eB_r.R{
+*`kJ)uP
K;Hgq4
public void splitterStop() 1R yE8DdP
{ gH,Pz
bStop = true; h 2JmRO
} =z"8#_3A
t_16icF9U
PJ&L7
} $0OOH4
jAcKSx$}y"
+e.w]\}
/* gMZ+kP`
**FileAccess.java {jwLVKT$
*//文件访问(定位，写) x)N QRd
package NetFox; VR1[-OE
import java.io.*; ?F!c"+C
&w`DF,k|
Sp?e!`|8
public class FileAccessI implements Serializable{ 0WKS
RL\?i~'KH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <}'=@a
RandomAccessFile oSavedFile; L<iRqayn
long nPos; {_Ll'S
G9am}qr
oD9L5c)
public FileAccessI() throws IOException An`*![
{ x@/:{B
this("",0); F#)bGi
} ~#P]NWW%.
fI<d&5&g
3OKs?i3A
public FileAccessI(String sName,long nPos) throws IOException %,<Ki]F
{ -&]!ig5v
oSavedFile = new RandomAccessFile(sName,"rw"); !\BM
this.nPos = nPos; '3sySsD&O
oSavedFile.seek(nPos); %I!2dXNFRF
} vGPsjxk&
#639N9a~
dS <*DP
public synchronized int write(byte[] b,int nStart,int nLen) d+5~^\lV
{ kw#-\RR_c
int n = -1; d:^B2~j
try{ _/%,cYVc8!
oSavedFile.write(b,nStart,nLen); eV(9I v[
n = nLen; 0b n%L~KU
} GP %hf{
catch(IOException e) |#SZdXg
{ v@M^ukk'}
e.printStackTrace (); /K1cP>oE
} h7T),UL
`F&~SU,
u,d5/`E
return n; )u=W?5%=}
} y5O &9Ckw
79d(UG'O
XpE847!soL
} Suo$wZ7J
}P{Wk7#Jq
<Q- m &
/* ;y1/b(t
**SiteInfoBean.java yf8kBT:&S
*/ "8cI]~V
package NetFox; &|RTLGwX
vlEW{B;)Z
7:b.c
public class SiteInfoBean { eMFxdtH
{ %]imf|g.
|KS,k|).
private String sSiteURL; //Site's URL U-m MKRV
private String sFilePath; //Saved File's Path ,5ZQPICF
private String sFileName; //Saved File's Name =8<~pr-NO
private int nSplitter; //Count of Splited Downloading File 0jjtx'F
%+Z*-iX
iI7ocyUv
public SiteInfoBean() h4F%lGot
{//nSplitter的缺省值为5 3/Z>W|w#w
//default value of nSplitter is 5 ez*QP|F*9
this("","","",5); t:vBVDkD
} Sx e6&
Qs59IZ
!d!u{1Y&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pPo xx"y
{ cgQ6b.
sSiteURL= sURL; Myiv#rQ)
sFilePath = sPath; 66" 6>
sFileName = sName; 8,!Oup
this.nSplitter = nSpiltter; qz (x
:|niFK4
|Rhqi
} ~) w4Tq
i 61k
,J!$Q0e
public String getSSiteURL() ,R<9yEWm
{ IVxZ.5:L$
return sSiteURL; 1TGRIe)
} *0eU_*A^zO
ty pbwfM]
>X05f#c"v/
public void setSSiteURL(String value) pe+h8
{ GbL1<P$V
sSiteURL = value; 9jEH"`qqk
} h3 XSt
0*rD'?)K+
b"N!#&O]
public String getSFilePath() M~|7gK.m1
{ /9I/^i~
return sFilePath; PS[ C!s&KE
} }58MDpOF1
8j3Y&m4^
NM![WvtjW
public void setSFilePath(String value) zB`woI28
{ ?&~q^t?u
sFilePath = value; xSK#ovH2
} W [K.|8ho
Xw!\,"{s
*pS 7,Hm
public String getSFileName() \P?X`]NwnO
{ ]FTi2B{}H
return sFileName; IY#:v%U
} 9N}\>L)_
5Q"w{ n
{o)pwM"@(
public void setSFileName(String value) ^9q#,6
{ g;8 wP5i
sFileName = value; _J W|3q
} er)I".|
Xzf,S;XV~
0zq'Nf?#3
public int getNSplitter() S\&3t}_
{ `;;l {8
return nSplitter; %g.cE}^
} uy3<2L#.
wAprksZL#
&gY) x{
public void setNSplitter(int nCount) L8PX SJ
{ tMiIlf!>p
nSplitter = nCount; Ls9NQy
} cpltTJFg
} @q/g%-WNz
Q[7i
`/P/2{,~
/* Wa<<"x$
**Utility.java i!?gga
*/ ~,HFd`
package NetFox; iT4*~(p 3
6- i.*!I 8
'YNdrvz
public class Utility { 4F~^RR"
=W.}&
D'#Q`H
public Utility() 1I9v`eT4
{ @9gZH_ur>E
^}d]O(
&P|[YP37_
} x [FLV8`b|
<s'de$[
//线程睡眠 !-f Bw
public static void sleep(int nSecond) *n? 1C"l
{ {G:y?q'z
try{ &oS$<
Thread.sleep(nSecond); _]>1(8_N
} FI$:R
catch(Exception e) 'RK"/ZhqE
{ PX 8UVA
e.printStackTrace (); r<e%;S
} 5XZ!yYB?
} @%R<3!3v
'+cI W(F?
//日志 y~ =H`PAE
public static void log(String sMsg) `um,S
{ ^hC'\09=c
System.err.println(sMsg); 2ndn8_l
} \j>7x
37/n"\4
?0VR2Yb${b
public static void log(int sMsg) yJm"vN
{ aKbmj
System.err.println(sMsg); %T{]l;5
} }Q/onBt
} AC) M2;
jV3PTU
=^nb+}Nz(
/* _95296
**TestMethod.java DYD<?._I
*/ .w9LJ
package NetFox; ^"/^)Lb!@M
&N|$G8\CY
Iry$z^
public class TestMethod { 9B: 3Ha=
+T+@g8S
O<gfZ>
public TestMethod() k&]nF,f
{ ///xx/weblogic60b2_win.exe Z',!LK!
try{ Ma[EgG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {3tzr;c?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9Eyx Ob
SiteFileFetch fileFetch = new SiteFileFetch(bean); L[G O6l
fileFetch.start(); ??rS h Mu
} 0mY Y:?v
catch(Exception e){e.printStackTrace ();} 5AYOM=O]t
'YNaLZ20
=Ph8&l7~sp
} x *eU~e_jP
,fVD`RR(W?
11[lc2
public static void main(String[] args) HGDrH
{ l90mM'[
new TestMethod(); o\IMYT
} 'ZfgCu)St
} Ey46JO"
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