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)); G$B( AWL
} Pgg\(D#X`
for(int i=0;i<nEndPos.length-1;i++) ub0uxvz
{ gI SP .
nEndPos = nStartPos[i+1]; ?4 fXCb]7
} NlS/PWc6(
nEndPos[nEndPos.length-1] = nFileLength; ] 3@.)
} }bxW@(bs
} 8;C_@
x!08FL)
lnk`D(>W
//启动子线程 Gz9w1[t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5uU.K3G7
for(int i=0;i<nStartPos.length;i++) Ikn)XZU^
{ z!r-g(^G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7z=zJ4C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3. kP,
nStartPos,nEndPos,i); gfPht 5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -!k$ Z
fileSplitterFetch.start(); "#a_--"k9
} 1b,,uI_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cx(aMcX6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;QA`2$Ow
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .%pbKi `
nEndPos = " + nFileLength); :q xd])-
// fileSplitterFetch[nPos.length-1].start(); Xo{|m[,
Gs% cod
q@}eYQ=P|e
//等待子线程结束 Gqz<;y
//int count = 0; ;gC.fpu
//是否结束while循环 #=G[~m\
boolean breakWhile = false; q-g3!
+x3T^G
b`=\<u8
while(!bStop) %ifq4'?Z
{ '<A:`V9M}v
write_nPos(); *P#okwp
Utility.sleep(500); wap@q6fz<
breakWhile = true; f<`is+"
py9HUyr5eZ
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for(int i=0;i<nStartPos.length;i++) S|{'.XG
{ *[-% .=[7
if(!fileSplitterFetch.bDownOver) >>ncq$
{ lAxbF
breakWhile = false; UUf-G0/P
break; nnV(MB4z1
} kXmnLxhS/
} SOq{`~,4B
if(breakWhile) ~qG`~/7
break; Jv|uI1V
F3aOKV^
0jlwL
//count++; hpxqL%r
//if(count>4) E0miX)AG
// siteStop(); -gWqq7O
} | Vtd!9
#sn2Vmi
Jzg>Y?jN R
System.err.println("文件下载结束！"); SA| AS<
} N6"b OxJ(
catch(Exception e){e.printStackTrace ();} f xWW"B*A
} "pDwN$c
FZW)C'j
FY^[?lj
//获得文件长度 dU7+rc2,CU
public long getFileSize() h@5mVTb}i
{ TsPx"+>7`
int nFileLength = -1; ^r u1QDT
try{ fgs){Ng`
URL url = new URL(siteInfoBean.getSSiteURL()); 8| 6:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yA8e"$
httpConnection.setRequestProperty("User-Agent","NetFox"); rNgFsFQ>.
s<i& q {r
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int responseCode=httpConnection.getResponseCode(); ]}3AP!:
if(responseCode>=400) $c!cO" U
{ %6\e_y%
processErrorCode(responseCode); BI'}
return -2; //-2 represent access is error :|s!_G<
} G8w<^z>pTg
u7_IO
U;Iqz1S
String sHeader; ^^u{W|'CaH
%nTgrgS(=
_B@=fY(g!
for(int i=1;;i++) /'V(F* g
{ $*035f
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qno8qF*
//Utility.log(in.readLine()); 1}moT#
sHeader=httpConnection.getHeaderFieldKey(i); vtvF)jlX
if(sHeader!=null) "ooq1 0P
{ ionFPc].
if(sHeader.equals("Content-Length")) .Ulrv5wJ
{ 1@&i ju5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?onaJ=mT
break; He#5d!cf:M
} xz-z" 8d
} EJM6TI"
else gWxpGW^eZ~
break; MZyzc{c,
} "f/Su(6{0
} 5'JONw'\
catch(IOException e){e.printStackTrace ();} Qi 3di
catch(Exception e){e.printStackTrace ();} or?@Ti;
Vv"JN?dHi
aZ[ aZU
Utility.log(nFileLength); Uxla,CCp-
~ .}
82S?@%}#J
return nFileLength; e)pQh&uD
} ,_STt)
{XT3M{`rWL
^sLnKAN
//保存下载信息（文件指针位置） :L~{Q>o
private void write_nPos() Q\pTyNAYn
{ =Kq/EDe
try{ }ze,6T*z
output = new DataOutputStream(new FileOutputStream(tmpFile)); cQ= "3M)~r
output.writeInt(nStartPos.length); RTPxAp+\5
for(int i=0;i<nStartPos.length;i++) ::k>V\;
{ FtaO@5pS54
// output.writeLong(nPos); k<1BE^[V
output.writeLong(fileSplitterFetch.nStartPos); DB1GW,
output.writeLong(fileSplitterFetch.nEndPos); 0q|.]:][Eo
} >/*wlY!E
output.close(); BoJYP
} >k:BG{$Kae
catch(IOException e){e.printStackTrace ();} T7vSp<i/
catch(Exception e){e.printStackTrace ();} YL(7l|^!
} 85>WK+=
9ANC,+0p
aq'dC=y
//读取保存的下载信息（文件指针位置） ikr|P&e#u
private void read_nPos() /%El0X
{ gk"0r\Eq
try{ :6~DOvY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O}4(v#
int nCount = input.readInt(); 7MRu=Z.-b
nStartPos = new long[nCount]; OQ[E-%v1 R
nEndPos = new long[nCount]; t7A '
for(int i=0;i<nStartPos.length;i++) KC+C?]~M
{ qTbY'V5A
nStartPos = input.readLong(); K"p$ga{
nEndPos = input.readLong(); >Oary
} BXNt@%
input.close(); >d.o1<
} ``%uq)G=D
catch(IOException e){e.printStackTrace ();} W<J".2D
catch(Exception e){e.printStackTrace ();} aBo8?VV]8
} ]_cBd)3P}
YeN /J.R
ttEQgkd`
private void processErrorCode(int nErrorCode) Z3:M%)e_u$
{ I6bekOvP
System.err.println("Error Code : " + nErrorCode); <SiD m-=E
} 6XVr-ef
?{bF3Mz=
-7GF2 @
//停止文件下载 ye-o'%{
public void siteStop() ]SNA2?q
{ rgQ6/3}qc
bStop = true; cR;zNS
for(int i=0;i<nStartPos.length;i++) K<@gU\-!
fileSplitterFetch.splitterStop(); S@AHI!"h=V
s%tPGjMq
%s.hqr,I
} mL\j^q,Y
} )` nX~_'p
//负责部分文件的抓取 _%g}d/v}pO
**FileSplitterFetch.java W)3IS&;P
*/ oY!nM%z/
package NetFox; UlBg6
]LFY2w<
Q'f!392|
import java.io.*; _dCsYI%
import java.net.*; +Eil:Jz
A;e[-5@
[ vU$zZ<
public class FileSplitterFetch extends Thread { &Gp~)%
x+j5vzhG)
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String sURL; //File URL !V~`e9[rl
long nStartPos; //File Snippet Start Position al/3$0#U
long nEndPos; //File Snippet End Position 1}#(4tw)
int nThreadID; //Thread's ID w(w%~;\kLP
boolean bDownOver = false; //Downing is over <ex,@{n4
boolean bStop = false; //Stop identical lO482l_t
FileAccessI fileAccessI = null; //File Access interface F$kLft[:
TGnyN'P|
s>Eu[uA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M8Y\1#~
{ 2ql7*g?Uq@
this.sURL = sURL; x`'2oz=,F4
this.nStartPos = nStart; %|(~k*s4
this.nEndPos = nEnd; 1tvgM !.
nThreadID = id; c5_?jKpl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >G`=8Ku
} (k?,+jnR
4l! ^"=rh
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public void run() xyO]Evg
{ ygm4Aj>
while(nStartPos < nEndPos && !bStop) h.Cr;w,2R
{ 0{ovLzW
{7^7)^@
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try{ rvT75dV0
URL url = new URL(sURL); MpbH!2J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .pNPC|XU
httpConnection.setRequestProperty("User-Agent","NetFox"); `Q2 `":
String sProperty = "bytes="+nStartPos+"-"; iqecm]Z0
httpConnection.setRequestProperty("RANGE",sProperty); {e,m<mAi
Utility.log(sProperty); 1Yt;1k'
fo])=KM
$KL5Z#K
InputStream input = httpConnection.getInputStream(); &wj;:f
//logResponseHead(httpConnection); `Q!|/B
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p#}38`
byte[] b = new byte[1024]; YH`/;H=$G/
int nRead; L2>UA<@mZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zn5
{ v'`9^3(-
nStartPos += fileAccessI.write(b,0,nRead); )i&9)_ro
//if(nThreadID == 1) M70Xdn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A:3bL: ;t
} +O23@G?x
'>(R'g42n
fRo_rj _
Utility.log("Thread " + nThreadID + " is over!"); T:Dp+m!\{
bDownOver = true; ]saf<?fzr
//nPos = fileAccessI.write (b,0,nRead); mLM$dk3
} ;czMsHu0X
catch(Exception e){e.printStackTrace ();} <a *X&P
} 3=xb%Upw
} Vm]ltiTVk
S5ka;g
P/._ tQu6
//打印回应的头信息 }fw;{&s{z
public void logResponseHead(HttpURLConnection con) yTw0\yiO
{ qPdNI1 |
for(int i=1;;i++) ,)A^3Q*
{ fclmxTy
String header=con.getHeaderFieldKey(i); }~dXz?{p8
if(header!=null) E"iH$NN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JsOPI]
Utility.log(header+" : "+con.getHeaderField(header)); uf,4GPo,
else K^AX=B
break; XtfO;`
} <Ft6d
} ^GdU$%aa
}NPF]P;
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public void splitterStop() Nd/iMV6V;
{ +=%13cA*U
bStop = true; b3e:F{n ^
} Kg&{ ?&
ay#cW.,
9z5K -s
} ")7,ZN;
Oy[1_qfP
/h%<e
/* f&t]O$
**FileAccess.java 5=Mm=HyI2
*//文件访问(定位，写) Y-&r_s_~
package NetFox; 70&v`"
import java.io.*; (+>~6SE
Y."ujo#bB
-yeQQ4b
public class FileAccessI implements Serializable{ (r`+q[
evPr~_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a>`\^>G4
RandomAccessFile oSavedFile; [8.ufpZ
long nPos; "|`8mNC
K|];fd U
{ yU1db^
public FileAccessI() throws IOException .Ozfj@ f
{ gs 8w/
this("",0); @~fg[)7M
} MK[l*=\s
:N^1T6v
t$r^'ZN
public FileAccessI(String sName,long nPos) throws IOException W^0F(9~!(
{ N+l~r]: &
oSavedFile = new RandomAccessFile(sName,"rw"); C.s{&
this.nPos = nPos; \(.&E`r
oSavedFile.seek(nPos); `|wH=
} OYC4iI
;6t>!2I>C
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public synchronized int write(byte[] b,int nStart,int nLen) b$[_(QUw
{ ]R}#3(]1
int n = -1; j>eL&.d
try{ E!Hq%L!/
oSavedFile.write(b,nStart,nLen); 28SlFu?
n = nLen; rui}a=rs
} [e3|yE6
catch(IOException e) 9:A>a3KOH
{ '*!R gbj;
e.printStackTrace (); *jGB/ y
} [6 wI22
[V{JuG;s
KoiU\r
return n; wxsJB2
} ^j';4'
%9[GP7?
PTA;a0A
} aRq7x~j )\
51.F,uY
a\vf{2
/* CB_(9T72H
**SiteInfoBean.java :tdx:
*/ VbM5]UT/
package NetFox; /}2 bsiJT
>?'q P ]
zJI/j _~W
public class SiteInfoBean { ,.]e~O4R
Y:^ =jV7
!W^2?pqN
private String sSiteURL; //Site's URL _4o2AS:j
private String sFilePath; //Saved File's Path vKAHf;1
private String sFileName; //Saved File's Name IG`~^-}7lR
private int nSplitter; //Count of Splited Downloading File uA C:&
p$f#W
,p1 (0i
public SiteInfoBean() rRcfZZ~` M
{//nSplitter的缺省值为5 tt[P{mMQ
//default value of nSplitter is 5 cLr? B;FS
this("","","",5); Ms1G&NYP
} ZyCAl9{p
Q[J,j+f<
<B`}18x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kjaz{&P
{ ><LIOFqsS
sSiteURL= sURL; Z<jRZH*L
sFilePath = sPath; {N)\It
sFileName = sName; Ez?vJDd
this.nSplitter = nSpiltter; :FG}k Y
Hxb{bF
C>v
} W{ eu_
{Hp?rY@
kjNA~{
public String getSSiteURL() cD0
{ F1M@$S,
return sSiteURL; QIi*'21a+
} pC8(>gV<h
enG6T
YL){o$-N"J
public void setSSiteURL(String value) v^@L?{"}8
{ y{u6t 3
sSiteURL = value; yl 0?Y
} {6 #3`
x ?^c:`.
Z6D4VZVF
public String getSFilePath() ^{6Y7T]
{ FT|*~_@
return sFilePath; iM8hGQ`
} QMtt:f]?i
{)b`fq
`yQHPN0/
public void setSFilePath(String value) dC(6s=4
{ !ox&`
sFilePath = value; d[~c-G6
} |o!<@/iH=
X[@>1tl
*uEU9fX
public String getSFileName() v~jN,f*
{ 1'aS2vB9
return sFileName; xR_]^Get
} 3M%EK2,
_KZ(Yq>SdY
="A[*:hC"
public void setSFileName(String value) N23s{S t
{ 2~ 'Q#(
sFileName = value; Q@$1!9m
} dH`a|SVW9
fx;5j;
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public int getNSplitter() 20fCWVw}?}
{ fLD9RZ8_
return nSplitter; _eO]awsA
} [w{ZP4d>
k&~vVx
s &.Z;X
public void setNSplitter(int nCount) il#rdJ1@t
{ e<p$Op
nSplitter = nCount; ?0?'
} PN.6BJvu
} kBONP^xI
r p@=
i44:VR|
/* \6lXsu;I.X
**Utility.java x _2]G'
*/ ze4/XR
package NetFox; '@fk(~|
&>s(f-\8
;zCHEz
public class Utility { RF;N]A?*
yjSN;3t71
`2@-'/$\I|
public Utility() xS(sRx+A
{ TWs|lhC7!
:w];N|48s
kqyMrZ#
} t =*K?'ly
c^bA]l^a
//线程睡眠 8odVdivh
public static void sleep(int nSecond) HhpP}9P;
{ @i`gR%
try{ w+MdQ@'5
Thread.sleep(nSecond); )T4L^^`
} `773& \PK
catch(Exception e) z)0VP QMT
{ G{"1I
e.printStackTrace (); %b*%'#iK
} )R|7> 97
} a>kDG <.A
i]YQq!B
//日志 n-=\n6"P
public static void log(String sMsg) $bo^UYZ6
{ pP r<8tm[
System.err.println(sMsg); {10ms_s
} tS9m8(Hr%Q
1y@-
H,I}R
public static void log(int sMsg) ~FsUK;?
{ kN^)6
System.err.println(sMsg); B.WJ6.DkS
} y H'\<bT
} ]SPB c
=&pbh
G8&'*7Bb
/* Yn#8uaU
**TestMethod.java PWmz7*/
*/ 68!]q(!6F
package NetFox; SH(kUL5
N0piL6Js
Stc\P]%d
public class TestMethod { - VE#:&
MCCZh{uo
ku{aOV%
public TestMethod() <-?B#
{ ///xx/weblogic60b2_win.exe 9s!/yiP5
try{ 4sAshrUf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q)~qd$yMS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M'HOw)U
SiteFileFetch fileFetch = new SiteFileFetch(bean); j"V$J8)[
fileFetch.start(); 35>}$1?-6
} 6a@~;!GlI
catch(Exception e){e.printStackTrace ();} BNy"YK$
6Te}"t>
Y;w]u_
} S3_4i;K\
HDEG/k/~m
+doT^&2u*
public static void main(String[] args) \PFx# :-c
{ |W <:rT
new TestMethod(); IBqY$K+l
} /OP*ARoC21
} 'l:2R,cP
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