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)); SEIJ+u9XsA
} yw*| HT
for(int i=0;i<nEndPos.length-1;i++) *V{Y.`\
{ KB8_yo{y
nEndPos = nStartPos[i+1]; "8/BVW^bv
} uuYeXI;
nEndPos[nEndPos.length-1] = nFileLength; "6>+IF
} #dkSAS
} m=V69 a#
15M!erT
b ; U
//启动子线程 |};-.}u^`h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t<MO~_`!
for(int i=0;i<nStartPos.length;i++) bCV_jR+
{ bOD]`*q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hZ-?-F?*@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #^xj"}o@
nStartPos,nEndPos,i); YA~`R~9d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^IO\J{U{"x
fileSplitterFetch.start(); EC7)M}H
} kn}bb*eZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uIR/^o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \ `|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6`Diz_(
nEndPos = " + nFileLength); QUWx\hqE
// fileSplitterFetch[nPos.length-1].start(); {gI%-
$j/#IzD1D
BB.120v&N
//等待子线程结束 drS>~lSxB
//int count = 0; 'k/:3?R
//是否结束while循环 *&~ '
boolean breakWhile = false; ex8}./mjJ
*z)+'D*+
R6\|:mI,$
while(!bStop) -V=,x3Zew
{ r}-vOPn`E
write_nPos(); smHQ'4x9
Utility.sleep(500); 1Sd<cOEd
breakWhile = true; pI( H7 (
- @tL]]
;OSEMgB1
for(int i=0;i<nStartPos.length;i++) TbgIr
{ J9lG0
if(!fileSplitterFetch.bDownOver) VMw[M^
{ fwv.^kx
breakWhile = false; Gp2Cwyv
break; NGmXF_kqN
} o':K4r;
} s,-}}6WO
if(breakWhile) /}nq?Vf
break; ]fJ9.Js
vGchKN~_
lf_q6y
//count++; p_CCKU
//if(count>4) M2LW[z
// siteStop(); &0SgEUZr
} CgKFI
.J\i!
fr8hT(,s)
System.err.println("文件下载结束！"); T*92o:^
} ;I~UQgE6H
catch(Exception e){e.printStackTrace ();} &_,.*tha
} Cw h[R
U9"Ij}
3 ]w a8|
//获得文件长度 fK+[r1^
public long getFileSize() rS_pv=0S
{ fkD-mRKw
int nFileLength = -1; ~LJtlJ 0
try{ [uFv_G{H
URL url = new URL(siteInfoBean.getSSiteURL()); 'W/AYF^5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +{WZpP},v
httpConnection.setRequestProperty("User-Agent","NetFox"); jm,:jkr
:b<<
0iVeM!bM
int responseCode=httpConnection.getResponseCode(); }[]1`2qD
if(responseCode>=400) &;%,Axc
{ n\u3$nGL1`
processErrorCode(responseCode); i7\MVI8
return -2; //-2 represent access is error .5iXOS0 G
} yH]w(z5Z
8r48+_y3u
pf#~|n#t
String sHeader; s"(F({J
D'Uv7Mis
|v:fP;zc
for(int i=1;;i++) `/9&o;qM
{ 4v.i!U# {
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +HoCG;C{
//Utility.log(in.readLine()); bM"d$tl$?'
sHeader=httpConnection.getHeaderFieldKey(i); =:m6ge@C&H
if(sHeader!=null) ai;-_M+$
{ 3q.HZfN~
if(sHeader.equals("Content-Length")) Y/qs\c+
{ \{ff7_mLo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CykvTV Q
break; T*](oA@
} _7,4C?
} ,{BF`5bn|
else S(G&{KG
break; G1ED=N_#
} jk1mP6'P|
} mw~$;64;a
catch(IOException e){e.printStackTrace ();} a~F\2`Q
catch(Exception e){e.printStackTrace ();} XRXQ 7\n
K.42 VM)F
[k60=$y
Utility.log(nFileLength); +4V"&S|&
c? >;UzM
d%#5roR4<
return nFileLength; %APeQy"6#^
} Em/? 4&
p`}G"DM
.ViOf){U\
//保存下载信息（文件指针位置） !XT2'6nu
private void write_nPos() B X Et]+Q
{ Mi7LyIu
try{ 2]+f<Z[/
output = new DataOutputStream(new FileOutputStream(tmpFile)); !~te&ccPE
output.writeInt(nStartPos.length); .{"wliC2
for(int i=0;i<nStartPos.length;i++) E*VOyH2[
{ `$ZBIe/u
// output.writeLong(nPos); h4=7{0[
output.writeLong(fileSplitterFetch.nStartPos); 3j/~XT
output.writeLong(fileSplitterFetch.nEndPos); 7$7#z\VWu
} 2xt$w%
output.close(); < [q{0,
} sH :_sOV*
catch(IOException e){e.printStackTrace ();} fPab%>/T{
catch(Exception e){e.printStackTrace ();} yXCJ?
} hh<ryuZ
"2hs=^&8
0134mw%jk
//读取保存的下载信息（文件指针位置） &@z M<A
private void read_nPos() "/{H=X3was
{ =&y6mQ
try{ WJii0+8e
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }=s64O9j
int nCount = input.readInt(); \)2~oN
nStartPos = new long[nCount]; lj@ibA]
nEndPos = new long[nCount]; <O4W!UVg
for(int i=0;i<nStartPos.length;i++) b@9d@@/wx
{ Bu7aeBP
nStartPos = input.readLong(); !z"nJC
nEndPos = input.readLong(); /C/I_S}H
} ?J28@rM
input.close(); Sw~L M&A
} hd#MV!ti
catch(IOException e){e.printStackTrace ();} LteZ7e
catch(Exception e){e.printStackTrace ();} y#-~L-J_R
} oZw#]Q@
>"pHk@AWK
e{}vT$-
private void processErrorCode(int nErrorCode) P@8S|#LpZ
{ )KUEkslR:
System.err.println("Error Code : " + nErrorCode); 6kdcFcV-]
} 7loIjT7
m&+V@H
n*A"}i`ix
//停止文件下载 b:W x[+
public void siteStop() d5qGTT ~a
{ ?d@zTAI
bStop = true; ""x>-j4
for(int i=0;i<nStartPos.length;i++) Frum@n
fileSplitterFetch.splitterStop(); @P6*4W
RpU.v `
]I(<hDuRp
} aU%QJ#j
} '?qI_LP?
//负责部分文件的抓取 "T' QbK0
**FileSplitterFetch.java [ Ru( H
*/ 0;2ApYks
package NetFox; Ex4)R2c*
a5uBQ?
]w~ECP(ap
import java.io.*; [}Y_O*C !
import java.net.*; 1NQU96
eRB K= X
xs$.EY:k
public class FileSplitterFetch extends Thread { X?n($z/{
pu Z0_1uN
:zsMkdU
String sURL; //File URL `f\+aD'u
long nStartPos; //File Snippet Start Position ,*g.?q@W2
long nEndPos; //File Snippet End Position O*m9qF<
int nThreadID; //Thread's ID dS;Ui]/J
boolean bDownOver = false; //Downing is over \>c1Z5H>
boolean bStop = false; //Stop identical TS@U0Ror
FileAccessI fileAccessI = null; //File Access interface iKAqM{(
FUs57 V
betTAbF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !X+}W[Ic^
{ 3'6by!N,d
this.sURL = sURL; tiTh7qYi9
this.nStartPos = nStart; /9SNXjfbt
this.nEndPos = nEnd; 0"DS>:Ntk
nThreadID = id; |!*abc\`(`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mjJ/rx{kbw
} xOdLct
-\V;Gw8mD
Zxn>]Z_
public void run() 7nk3^$|
{ j:xm>X'
while(nStartPos < nEndPos && !bStop) uF<\|y rFt
{ YL9Tsw
XrN]}S$N
n[
try{ >o!5)\F
URL url = new URL(sURL); *DPKV$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /|,:'W%U
httpConnection.setRequestProperty("User-Agent","NetFox"); Y!3i3D
String sProperty = "bytes="+nStartPos+"-"; oE$zOS&2
httpConnection.setRequestProperty("RANGE",sProperty); :}[D;cx
Utility.log(sProperty); 9 N9Q#o$!.
F{FSmUxzK
JwcC9 O
InputStream input = httpConnection.getInputStream(); jP"yG#
//logResponseHead(httpConnection); JeU1r-i
b%|6y
E rnGX#@v
byte[] b = new byte[1024]; ts;C:.X
int nRead; b0yNc:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1'SpJL1u~
{ )C%S`d<%,
nStartPos += fileAccessI.write(b,0,nRead); tq2TiXo%
//if(nThreadID == 1) -59;Zn/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ; 8u5
} uAv'%/
<M M(Z
fx= %e
Utility.log("Thread " + nThreadID + " is over!"); `;z;=A*
bDownOver = true; Zie t-@}
//nPos = fileAccessI.write (b,0,nRead); MFsW
} %e1`wMa
catch(Exception e){e.printStackTrace ();} SOQR(UT
} ;N!W|G
} ki9vJ<
<k7q9"\4
LGPg\g`
//打印回应的头信息 1eMaKT_=
public void logResponseHead(HttpURLConnection con) vff`Xh>k(
{ m,#Us
for(int i=1;;i++) Y$N D
{ nIv/B/>pZ
String header=con.getHeaderFieldKey(i); F/0x`l
if(header!=null) ]hlYmT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }R)A%FKi@
Utility.log(header+" : "+con.getHeaderField(header)); 0j2M< W#
else lv\^@9r
break; ]M/*Beh
} jjJ l\Vn
} SAGECK[Ix
sr`)l&t?
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public void splitterStop() 7.7Z|lJ
{ e(Ub7L#
bStop = true; lZ5TDS
} %y R~dt'
CB>O%m[1
fg~9{1B
} 99&PY[f:{
MI*@^{G
T.iVY5^<
/* BxHfL8$1[$
**FileAccess.java mY/x|)MmM
*//文件访问(定位，写) #GA6vJ4^s
package NetFox; Ar1X mHq
import java.io.*; XOd
cKH By
Ol1P
public class FileAccessI implements Serializable{ hwdZP=X
KfMaVU=4P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j!hdi-aTU
RandomAccessFile oSavedFile; r`!S*zK
long nPos; cS#m\O
AX2On}&bf
9$e6?<`(Y
public FileAccessI() throws IOException ]6TX)1
{ e*jfxQ=qG
this("",0); n%}Vd `c
} _,5)
WU<C7
b5d;_-~d
public FileAccessI(String sName,long nPos) throws IOException p_l.a
{ bAm ,gP
oSavedFile = new RandomAccessFile(sName,"rw"); lO dwH"
this.nPos = nPos; TH#5j.uUs
oSavedFile.seek(nPos); %<Kw
} \A/??8cgXs
e8$OV4X
">NPp\t>/Z
public synchronized int write(byte[] b,int nStart,int nLen) g)#.|d+
{ ~4[4"Pi>|
int n = -1; #J)83
try{ R|O."&CAB
oSavedFile.write(b,nStart,nLen); PvB-Cqc
n = nLen; L(i0d[F
} JBvP {5
catch(IOException e) )6,Pmq~)
{ Ncle8=8
e.printStackTrace (); C4/p5J
} 34Z$a{ w
5W~-|8m
6o^sQ(]
return n; !ie'}|c
} e-/+e64Q@
#ysSfM6
/\|AHM
} e x`mu E
>ISN2Kn
f+j-M|A
/* (DrDWD4_
**SiteInfoBean.java ~q05xy8
*/ /E0/)@pDq
package NetFox; )#_:5^1
W! q-WU
u+/1ryp
public class SiteInfoBean { :OvTZ ?\
;L.RfP"5<
!w-`:d?
private String sSiteURL; //Site's URL YR} P;
private String sFilePath; //Saved File's Path @&LtIN#
private String sFileName; //Saved File's Name %44Z7
private int nSplitter; //Count of Splited Downloading File biw2f~V
g_F-PT>($
+axpIjI'
public SiteInfoBean() VUE6M\&z>
{//nSplitter的缺省值为5 q'~F6$kv5
//default value of nSplitter is 5 p{k^)5CR/
this("","","",5); vynchZ+g]
} qz2j55j
}m0hq+p^
U6Ws#e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #_}r)q
{ L:3
sSiteURL= sURL; E3<~C(APW
sFilePath = sPath; a}#Jcy!e
sFileName = sName; !>Ru= $9
this.nSplitter = nSpiltter; nt*nTtcE
dl&402
y%^TZ[S
} +`H{
y+.E}
V]I+>Zn| 7
public String getSSiteURL() voAen&>!
{ s@c.nT%BYL
return sSiteURL; ,Xt!dT-
} zBd)E21H
_onEXrM
]t|-
public void setSSiteURL(String value) xIh,UW#
{ x%\m/_5w%
sSiteURL = value; Kgw_c:/'
} K!a4>Du{
xp<p(y8e1d
DeTD.)pS
public String getSFilePath() &z"sT*3
{ |w7D&p$
return sFilePath; ~'aK[3
} :P1/kYg
!tL&Ktoj
ehCZhi~
public void setSFilePath(String value) uk)6%
{ !O-9W=NJ
sFilePath = value; Skn2-8;10
} 7,![oY[
ahJu+y
!W ,pjW%Y
public String getSFileName() |zaYIVE[
{ M~/R1\'&j
return sFileName; ,\cO>y@
} `aw5"ns^V
sF=8E8qa
D+:}D*_&
public void setSFileName(String value) t/HUG#W{
{ %ymM#5A
sFileName = value; j%y)%4F8
} IhYTK%^96
oA1d8*i^E
6%&RDrn
public int getNSplitter() U;Ne"Jh
{ %ut7T!Jp
return nSplitter; Q|`sYm'.
} }1/`<m
,9:0T LLR
`p.O
public void setNSplitter(int nCount) PN&;3z Z
{ jdF~0#vH
nSplitter = nCount; ~>( N<:N
} 8aSH0dX
} T)QT_ST.9
i[wEH1jR
;.g <u
/* p*^[ ~}N
**Utility.java F;&a=R!.
*/ `vijd(a?v
package NetFox; ~Uet)y<
oy)'wb~
Pd[&&!+gV
public class Utility { ZTwCFn
NpIx\\d
^:c"%<"='
public Utility() D`G ;kp
{ XtV=Gr8"
c!{]Z_d\
H)${"
} IO4 8sV }
< x==T4n/
//线程睡眠 34$qV{Y%y
public static void sleep(int nSecond) @9wug!,
{ ;1&7v
try{ 8+irul{H_
Thread.sleep(nSecond); = +=k(*
} vV?=r5j
catch(Exception e) )Z2l*fV
{ dgIEc]#pH
e.printStackTrace (); 0y"Ra%Y
} o1"-x
} v_zVhEtY
+$YluGEJ
//日志 #(5hV7i
public static void log(String sMsg) u\JYxNj1
{ MJ)aY2
System.err.println(sMsg); Po=@ 6oB
} jnl3P[uQ
h xCt[G@
H#LlxD)q
public static void log(int sMsg) $ 4& )
{ U6pG
System.err.println(sMsg); )ww#dJn
} h!"|Q"18
} zoU-*Rs6
f[bx|6
e"sz jY~V
/* K`25G_Y3@
**TestMethod.java X R =^zp?
*/ yE\dv)(<
package NetFox; >c~Fgs
lAM"l)Ij
YMSA[hm
public class TestMethod { wd/"! A4(
5GP,J,J
h zh%ML3L
public TestMethod() wjr1?c
{ ///xx/weblogic60b2_win.exe ]y3'6!
try{ 6uU2+I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); TzCNY@y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m),3J4(q
SiteFileFetch fileFetch = new SiteFileFetch(bean); BAq@H8*B
fileFetch.start(); 3+%c*}KC~
} "2}E ARa
catch(Exception e){e.printStackTrace ();} #^>5,M2
Vko1{$}t
tWNz:V
} !]W}I
5jpb`Axj#
f/r@9\x
public static void main(String[] args) (mOUbO8
{ >|Hd*pg))
new TestMethod(); Gj.u/l
} M=57 d7
} ZkyH<Aa
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