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)); #Nv)SCc
} W</\F&
for(int i=0;i<nEndPos.length-1;i++) +<$b6^>!$
{ 7T/hmVi_
nEndPos = nStartPos[i+1]; +2Wijrn
} ATkx_1]KM-
nEndPos[nEndPos.length-1] = nFileLength; )9~-^V0A^>
} t_NnQ4)=
} vE$n0bL2
:&\^r=D
iT,Ya-9"
//启动子线程 "LkI'>3}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0`~#H1TK
for(int i=0;i<nStartPos.length;i++) b3^d!#KVM
{ v?<Tkw ^F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X{-901J1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), IRY/0v
nStartPos,nEndPos,i); qt,;Yxx#^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p`T,VU&.
fileSplitterFetch.start(); P+(q38f[
} jImw_Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N}X7g0>hV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %WO4uOi:@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #4wia%}u
nEndPos = " + nFileLength); ]]!&>tOlI
// fileSplitterFetch[nPos.length-1].start(); !Jk|ha~r
Wo,"$Z6B
K;P<c,9X/
//等待子线程结束 N*6lyFcg
//int count = 0; -XMWN$Ah
//是否结束while循环 ^w+)A;?W
boolean breakWhile = false; DUlvlQW
=BVBCh
P{[@t_
while(!bStop) Ns5'K^
{ \\v1\
write_nPos(); vQsI^p
Utility.sleep(500); Gid6,J
breakWhile = true; WOR H4h9
wpV)y Q^
bPHtP\)
for(int i=0;i<nStartPos.length;i++) ~F^7L5d}C
{ BaXf=RsZ
if(!fileSplitterFetch.bDownOver) ]>H'CM4JR
{ [*W l=
breakWhile = false; OTV$8{
break; I*OJPFZ^4
} L`n Ma
} bY!1t}ALh
if(breakWhile) 65>}Q.p
break; I6.}r2?;A
-0:Equ?pz
%}1v-z
//count++; 4#Id0['
//if(count>4) 'FN+BvD
// siteStop(); u~\l~v^mj
} a~Nh6 x
~xakz BE
`2PvE4]%p
System.err.println("文件下载结束！"); M#o'hc
} :~4M9
catch(Exception e){e.printStackTrace ();} T.GB*
} AH'4k(-
j@C*kj;-
b5t:">wC
//获得文件长度 )L/o|%r!
public long getFileSize() D'Y=}I)8Dn
{ xG~7kj3
int nFileLength = -1; Rr"D)|Y;C(
try{ *z6m644H
URL url = new URL(siteInfoBean.getSSiteURL()); `ZZq Sc4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0.lOSAq
httpConnection.setRequestProperty("User-Agent","NetFox"); #{x4s?
pL pBP+i
I`4k5KB;
int responseCode=httpConnection.getResponseCode(); m'YYkq(5%Z
if(responseCode>=400) u7}C):@H
{ ]m@p? A$
processErrorCode(responseCode); s8|Fe_
return -2; //-2 represent access is error d[$YTw
} =L9;8THY
f0]`TjY
r0j+P%
String sHeader; _>4Qh#6K
@zi_@B
HsRQiai*
for(int i=1;;i++) &09g0K66
{ C[s='v~}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); C*&FApG
//Utility.log(in.readLine()); S?e*<s9k
sHeader=httpConnection.getHeaderFieldKey(i); k\A[p\
if(sHeader!=null) M$MFUGS'
{ 7kq6VS;p
if(sHeader.equals("Content-Length")) [&K"OQ^\2h
{ N={0A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ZP;WXB`
break; t^SND{[WcM
} mt*/%>@7R
} G[ gfD\
else Zt"3g6S
break; %W,V~kb
} {bMOT*X=A
} uG{/yJeU
catch(IOException e){e.printStackTrace ();} 4$MV]ldUI
catch(Exception e){e.printStackTrace ();} ,@r 0-gL
'q, L*
!B:wzb_
Utility.log(nFileLength); 7xoq:oP-}N
K}TSwY
9f_Qs4
return nFileLength; qJYEsI2M
} 3&"+)*/ m
r(DW,xoK0
3iBUIv
//保存下载信息（文件指针位置） ;noZmPa
private void write_nPos() *!&,)''
{ J[jzkzSu`
try{ `|f1^C^
output = new DataOutputStream(new FileOutputStream(tmpFile)); $.T\dm-
output.writeInt(nStartPos.length); }-2U,Xg[
for(int i=0;i<nStartPos.length;i++) [s&0O<Wv
{ Ah Rvyj
// output.writeLong(nPos); >@?`n}r|
output.writeLong(fileSplitterFetch.nStartPos); B'!I{LC
output.writeLong(fileSplitterFetch.nEndPos); C[Nh>V7=
} \3 M%vJ
output.close(); 26[m7\O
} JYO("f
catch(IOException e){e.printStackTrace ();} :BpXi|n;
catch(Exception e){e.printStackTrace ();} v/~Lfi
} FN"Ye*d
N`rz>6,k1
6<{XwmM
//读取保存的下载信息（文件指针位置） $i"IOp
private void read_nPos() h}yfL@
{ ;I!Vba
try{ Cm~z0c|T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7O\Qxc\
int nCount = input.readInt(); CjZIBMGc
nStartPos = new long[nCount]; F@rx/3 [
nEndPos = new long[nCount]; $J!WuOz4^i
for(int i=0;i<nStartPos.length;i++) j+NsNIJq
{ -mqL[ h,
nStartPos = input.readLong(); 9/$Cq
nEndPos = input.readLong(); l }WvO]
} re@;6o
input.close(); EN;4EC7tE
} "eZ~]m}L0
catch(IOException e){e.printStackTrace ();} UB3hC`N\
catch(Exception e){e.printStackTrace ();} O2N~&<^
} cs0rz= ZdH
3eR c>^wh
` 3h,Cy^
private void processErrorCode(int nErrorCode) `=19iAp.
{ E5 uk<e_
System.err.println("Error Code : " + nErrorCode); :@K~>^+U
} $_Q]3"U
a|kEza,]
gRg8D{
//停止文件下载 Q1[EiM3
public void siteStop() "`Y.5.
{ Y?xc#'
bStop = true; UIK4]cYC'
for(int i=0;i<nStartPos.length;i++) AGK{t+`
fileSplitterFetch.splitterStop(); Z:.*fs5
bD<hzOa
*IIuGtS
} (Ky$(Ubb#6
} .'zcD^
//负责部分文件的抓取 `[F[0fY-
**FileSplitterFetch.java QR{>]I
*/ ,| ~Pa
package NetFox; :YM1p&|fS
cg_j.=M-
m e2$ R>@
import java.io.*; CMC9%uq
import java.net.*; $mcq/W
(gjCm0#_%
h1Logm+m
public class FileSplitterFetch extends Thread { O>[B"mMt
Z!*k0<Z
rH9[x8e
String sURL; //File URL Z=zD~ka
long nStartPos; //File Snippet Start Position ?$~5ti#\
long nEndPos; //File Snippet End Position Q&8epO|J
int nThreadID; //Thread's ID 5;X3{$y
boolean bDownOver = false; //Downing is over qv)%)n
boolean bStop = false; //Stop identical g [c^7
FileAccessI fileAccessI = null; //File Access interface {"mb)zr
>N-l2?rE
".sRi
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kS<9cy[O
{ nJcY>Rp?
this.sURL = sURL; `Tc"a_p9t
this.nStartPos = nStart; Y%Tm `$^V
this.nEndPos = nEnd; j6#Vwcr
nThreadID = id; To =JE}jzo
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =PYS5\k
} CSlPrx2\
e|eWV{Dsz
$Qcr8~+a
public void run() q*7:L
{ z,c=."<z
while(nStartPos < nEndPos && !bStop) uQiW{Kja2
{ R/jHH{T3
pP^5y{
Y3bZ&G)
try{ *&tv(+P
URL url = new URL(sURL); T4h&ly5 f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oD=+
httpConnection.setRequestProperty("User-Agent","NetFox"); lD6PKZ\RIj
String sProperty = "bytes="+nStartPos+"-"; mO&zE;/[
httpConnection.setRequestProperty("RANGE",sProperty); n7pjj
Utility.log(sProperty); ]:.9:RmEV
x\5v^$
0`Y"xN`'i
InputStream input = httpConnection.getInputStream(); @o>3 Bv.
//logResponseHead(httpConnection); #PQhgli
ky I~
>DoP2]
byte[] b = new byte[1024]; _[,7DA.qc
int nRead; xP$\ }
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %H3 M0J2L
{ 7.bPPr&
nStartPos += fileAccessI.write(b,0,nRead); [WO>}rGw4
//if(nThreadID == 1) x,UP7=6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V=)' CCi{
} /A93mY[
*Ke\Yb
Uf#9y182*c
Utility.log("Thread " + nThreadID + " is over!"); #Q$+AdY|
bDownOver = true; }ZJ*N Y
//nPos = fileAccessI.write (b,0,nRead); wVkRrFJ
} +Sak_*fq
catch(Exception e){e.printStackTrace ();} &;[e
} PGhYkj2
} lS/l iI'Y
h I7ur
0N):8`dY
//打印回应的头信息 s3y"y_u
public void logResponseHead(HttpURLConnection con) S@cKo&^
{ (lt{$0
for(int i=1;;i++) ?wREX[Tqs
{ o ^""=Z
String header=con.getHeaderFieldKey(i); 30{WGc@l#
if(header!=null) ~2[mZias
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :(#5%6F
Utility.log(header+" : "+con.getHeaderField(header)); B}^l'p_u
else Z4369
break; 2X6L'!=
} 4DsHUc6
} LN`Y`G|op
`&i\q=u+
b{}ao
public void splitterStop() uA~?z:~=
{ m.Ki4NUm
bStop = true; G(gZL%M6
} bp>M&1^KY
d0;<Cw~Tl
Zu|qN*N4
} 6rMNp"!
o8fY!C)
}A&I@2d
/* %PC8}++
**FileAccess.java =)nJ'}x
*//文件访问(定位，写) G{gc]7\=Cd
package NetFox; $^`@lyr
import java.io.*; P.- `[
(: @7IWZf@
5=/j
public class FileAccessI implements Serializable{ w#{S=^`}
iC~ll!FA!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Kiq[PK
RandomAccessFile oSavedFile; cFr`9A\-n
long nPos; _kdt0Vr,L
F h+g@ u6
>tE6^7B*
public FileAccessI() throws IOException #,9#x]U#v
{ =Y5_@}\0
this("",0); xM![
} 6 tl#AJ-
%|'VucLx
rDv`E^\
public FileAccessI(String sName,long nPos) throws IOException Zu/w>
{ sBLOrbo
oSavedFile = new RandomAccessFile(sName,"rw"); {'yr)(:2M
this.nPos = nPos; H7}f[4S%
oSavedFile.seek(nPos); ^9 ^DA!'
} ! =*k+gpF
:M8y 2fh
{43J'WsJ
public synchronized int write(byte[] b,int nStart,int nLen) VcLzv{
{ \i3)/sZ?l
int n = -1; j+("4b'
try{ ;cGY
oSavedFile.write(b,nStart,nLen); >1$Vh=\OI
n = nLen; 'cA(-ghY/E
} .JV y}^Q\
catch(IOException e) Rd[^)q4d$w
{ Y(=A HmR
e.printStackTrace (); w%-S5#
} h!?rk|
|IDZMd0
r!~6.
return n; eIQ@){lJ-]
} @a,}k<@E
vURgR
Xn02p,,
} pO)5NbU
kAq#cLprG
}8'b}7!
/* !\!j?z=O8
**SiteInfoBean.java u}89v1._Jn
*/ b-RuUfUn0
package NetFox; m .R**g
0+/ew8~$
a}X.ewg
public class SiteInfoBean { t\-|J SZ
D9!$H!T _
?hYWxWW
private String sSiteURL; //Site's URL J3$@: S'
private String sFilePath; //Saved File's Path tGF3Hw^mS
private String sFileName; //Saved File's Name tac\Ki?
private int nSplitter; //Count of Splited Downloading File 6G{ Q@
F |aLF{
gv1y%(`|n(
public SiteInfoBean() FM7`q7d
{//nSplitter的缺省值为5 /!fJ`pu!
//default value of nSplitter is 5 zbjV>5
this("","","",5); nH B
} ?}#Iu-IA
y-{?0mLq
?in)kL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h4Xz"i{z
{ PJ\k|
sSiteURL= sURL; *,28@_EwY
sFilePath = sPath; 6Ad=#MM
sFileName = sName; L%+mD$@u
this.nSplitter = nSpiltter; dSe d6
""*g\
@2;cv?i)
} -d^'-s
N_/+B]r }T
{nw.bKq7
public String getSSiteURL() =_CH$F!U
{ W}#n.c4+
return sSiteURL; wF3 MzN=%
} r"|.`$:B
C[5dhFZ
^PUB~P/
public void setSSiteURL(String value) OY2u,LF9H
{ Jhfw$DF
sSiteURL = value; E6z&pM8<8
} .y lvJ$
[s{[ .0P]+
'V&Tlw|
public String getSFilePath() d{"@<0i?
{ '_5|9 }
return sFilePath; RT${7=
} ~/XDA:nfL:
XlnSh<e
v]Aop<KLX
public void setSFilePath(String value) lB.n5G
{ RhC|x,E
sFilePath = value; `3`.usw
} 8H|ac[hXK2
`YqXF=-
F)v
public String getSFileName() .R l7,1\
{ Pm,.[5uc
return sFileName; x2'pl (^
} 4-I7"pW5
".2d{B
7O:g;UI#
public void setSFileName(String value) N,l"9>CF
{ M8/:PmR<
sFileName = value; XUnw*3tPJ
} T#wG]DH;
pRd'\+
vPc*x5w-
public int getNSplitter() $HtGB]
{ 9Q!Z9n"8~)
return nSplitter; tzv4uD]
} _GrifGU\
vn!3Z!dm(
jw`05rw:
public void setNSplitter(int nCount) sG)aw`_j
{ jOzi89
nSplitter = nCount; ^bP`Iv
} zWH)\>X59
} x,zYNNx5g
@b,6W wc
lQBEq"7$
/* 7?{y&sf
**Utility.java @$'pMg
*/ TiF+rA{t
package NetFox; 3+(lKd
k>7bPR5Mw
n1PBpM9!
public class Utility { +vxOCN4}v
53gLz_ee
7mf&`.C np
public Utility() V )1.)XC
{ !zllvtK4
,aa 4Kh
?~4x/d%
} W)J MV
;Rpib[m
//线程睡眠 3W]gn8
public static void sleep(int nSecond) f*xr0l
{ :0QDV~bs
try{ T\g+w\N
Thread.sleep(nSecond); CWocb=E
} 3u&,3:
catch(Exception e) GC'e
{ |xg_z&dX
e.printStackTrace (); =5Nh}o(l?
} O ;[Mi
} GM?s8yZ<
aKWxLe
//日志 RRV%g!
public static void log(String sMsg) k!}(a0h
{ 8A.7q
System.err.println(sMsg); EmR82^_:
} d~QM@<SV
C=]<R<Xy
MkL2I+*
public static void log(int sMsg) _> x}MW+
{ \"))P1
System.err.println(sMsg); `GdH ,:S>
} q6w)zTpJGJ
} %ut8/T
|R _rfJh
Tjq1[Wq
/* 3Ovx)qKxd
**TestMethod.java ,[zSz8R
*/ T!ZjgCY}
package NetFox; WZY+c
(RV#piM
>}%#s`3W1_
public class TestMethod { AvB=/p@]
`[g$EXX
ES AX}uF
public TestMethod() 2xflRks
{ ///xx/weblogic60b2_win.exe ybw\^t
try{ pGjwI3_K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); , ?U)mYhI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NsP=l]
SiteFileFetch fileFetch = new SiteFileFetch(bean); <kPNe>-f
fileFetch.start(); !Q15qvRS
} t!*[nfR
catch(Exception e){e.printStackTrace ();} 1n[)({OQ
8.n#@%
T3@2e0u )
} _:=\h5}8
HbI{Xf[6LP
,;Wm>V)o
public static void main(String[] args) `bfUP s
{ wjwCs`
new TestMethod(); U4fv$gV
} R[j?\#
} Z4Dx:m-
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