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,87
} ( SC7m/
for(int i=0;i<nEndPos.length-1;i++) Aw_R $
{ DI2S %Nl
nEndPos = nStartPos[i+1]; 9I^H)~S
} \k$]GK-
nEndPos[nEndPos.length-1] = nFileLength; v]d?6g
} $AL|d[[T[
} p!rGPyGC
;1(qGy4
t`&s
//启动子线程 5BGv^Qb_2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BhhK|U/
for(int i=0;i<nStartPos.length;i++) 7\Yq]:;O
{ 37za^n?SG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e-T9HM&%P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), plz=G}Y
nStartPos,nEndPos,i); :u|UVp5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G41$oalQ1
fileSplitterFetch.start(); B=nx8s
} l*V72!Mv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ' m#Ymp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); z;@S_0M,Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a7 '\*
nEndPos = " + nFileLength); YRT}fd>R&
// fileSplitterFetch[nPos.length-1].start(); (HP={MrV
a}+_Yo(Q
:;gwdZ
//等待子线程结束 s$=B~l
//int count = 0; >=RHE@
//是否结束while循环 ;tIIEc
boolean breakWhile = false; {3yws4
&<;nl^
[+[fD
while(!bStop) y5opdIaT
{ nh_xbo5L[
write_nPos(); F\$}8,9
Utility.sleep(500); )-6[Bw
breakWhile = true; s13 d*
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for(int i=0;i<nStartPos.length;i++) tZ6v@W
{ }Q,C;!'"
if(!fileSplitterFetch.bDownOver) ZpP6Q
{ (j\UoKLRt
breakWhile = false; {~ vPq
break; Vt 5XC~jK
} "nS{ ;:
} r'}k`A5>
if(breakWhile) pz z`4VS:
break; [O =)FiY-
;Q%19f3,6
,@j&q
//count++; :Y&W)V-
//if(count>4) < oG\)!O
// siteStop(); MDXQj5s^
} &qj&WfrB,
1F%*k &R
;@$," P
System.err.println("文件下载结束！"); >Sl:Z ,g;
} Xv;ZAa
catch(Exception e){e.printStackTrace ();} u K&_IE}
} @ F"ShT0
7*W$GCd8
<Ucfd G&Lp
//获得文件长度 e2H'uMy;&
public long getFileSize() nT6iS}h
{ G7#~=W 2M
int nFileLength = -1; EwJn1Mvq
try{ l<:)rg^,
URL url = new URL(siteInfoBean.getSSiteURL()); t@mw f3,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +]2~@=<@
httpConnection.setRequestProperty("User-Agent","NetFox"); uTFEI.N
6O?Sr,
9U%}"uE
int responseCode=httpConnection.getResponseCode(); jF2GHyB
if(responseCode>=400) >@\?\!Go
{ {.[,ee-)9
processErrorCode(responseCode); WN?`Od:y
return -2; //-2 represent access is error nWg)zj:
} [UrS%]OSR
s%re>)=|
|0Ug~jKU
String sHeader; X_yU"U
]uXsl0'`V
Yl3PZ*#@ Q
for(int i=1;;i++) @g` ,'r
{ eyp\h8!u_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [_B&7#3>7
//Utility.log(in.readLine()); H s 3*OhK\
sHeader=httpConnection.getHeaderFieldKey(i); x"=q+sA
if(sHeader!=null) m.X+sP-e
{ 3S21DC@Y
if(sHeader.equals("Content-Length")) LPgI"6cP
{ y^fU_L?p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [~0q )
break; tUnVdh6L.B
} e;Z`&
} =C}<0<"iF
else @_Oe`j^
break; Z-V%lRQ=b
} ~&jCz4M
} *g}&&$b0
catch(IOException e){e.printStackTrace ();} r\D8_S_
catch(Exception e){e.printStackTrace ();} T`G"2|ISS
S}I=i>QB
Y3&ecEE
Utility.log(nFileLength); <08V-
-L3RzX
BGjTa.&
return nFileLength; (pg9cM]NA
} n[-!Jp[
HK.J/Zr
p-Btbhv
//保存下载信息（文件指针位置） fL:Fn"Nv
private void write_nPos() \mGM#E
{ X"GQ^]$O
try{ h}_q
output = new DataOutputStream(new FileOutputStream(tmpFile)); k,(_R=
output.writeInt(nStartPos.length); Mb!^_cS(
for(int i=0;i<nStartPos.length;i++) K>6p5*&
{ U]$3NIe
// output.writeLong(nPos); %tLq&tyeY
output.writeLong(fileSplitterFetch.nStartPos); C_)>VPD
output.writeLong(fileSplitterFetch.nEndPos); R:p,Hav<q
} #+\G- =-
output.close(); r/f;\w7
} (La
catch(IOException e){e.printStackTrace ();} '_Oprx
catch(Exception e){e.printStackTrace ();} B/}>UHM
} {D#`+uw
h#nQd=H<g#
tTt~W5lo
//读取保存的下载信息（文件指针位置） W@=ilW3RD
private void read_nPos() * vD<6qf
{ .|-y+9IP
try{ vS#]RW&j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yL-L2
int nCount = input.readInt(); t"fD"Xpj
nStartPos = new long[nCount]; ],|B4\b;
nEndPos = new long[nCount]; e+TNG &_
for(int i=0;i<nStartPos.length;i++) (#qVtN`t
{ 9~yuyv4$
nStartPos = input.readLong(); ZxQP,Ys_Y
nEndPos = input.readLong(); g~b'}^J
} t,_[nu(~8%
input.close(); 5JXLfYTUI
} u!W00;`L
catch(IOException e){e.printStackTrace ();} D.?gV_
catch(Exception e){e.printStackTrace ();} 5"U7I{\
} \\JXY*DA:+
4NIfQYC.
*VB*/^6A
private void processErrorCode(int nErrorCode) jC%I]#!n
{ |Oe6OCPf
System.err.println("Error Code : " + nErrorCode); dQ]j r.
} RU=%yk-gM
;f Gi5=-
`u-Y 5mY
//停止文件下载 >B0S5:S$W
public void siteStop() `Ec+i
{ H'2 =yhtVh
bStop = true; {YFru6$
for(int i=0;i<nStartPos.length;i++) al/~
fileSplitterFetch.splitterStop(); U' Cp3>
&n|gPp77$
;<\*(rUe
} d<o
} 5|Qr"c$p
//负责部分文件的抓取 aF:LL>H
**FileSplitterFetch.java H@zpw1fH+
*/ -84Z8?_
package NetFox; Tb^9J7]
y06 2/$*$
f+&yc'[
import java.io.*; JLhp25{x
import java.net.*; sdLFBiR
f[w$3
B}W^s;h
public class FileSplitterFetch extends Thread { F3q5!1
8Bhng;jX
A.[T#ZB.4
String sURL; //File URL dn Xc- <
long nStartPos; //File Snippet Start Position 4?Io@[7A)
long nEndPos; //File Snippet End Position vd~O:=)4
int nThreadID; //Thread's ID <FP-]R)
boolean bDownOver = false; //Downing is over wZ^/-
boolean bStop = false; //Stop identical ^P[*yf
FileAccessI fileAccessI = null; //File Access interface ;(V=disU/
f5N~K>
MmX42;Pw
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aD4ln]sFxG
{ XP'KgTF
this.sURL = sURL; -&c@c@dC
this.nStartPos = nStart; *G9;d0
this.nEndPos = nEnd; xsfq[}eH<
nThreadID = id; z#y<QH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 HBt?cA '
} thh, V
G 5)?!
pH4i6B*5
public void run() KT3[{lr
{ ?}W:DGudZ
while(nStartPos < nEndPos && !bStop) w:qwU\U>x
{ 2]@U$E='s
h.67]U7m
{vaq,2_w
try{ F*a+&% Q
URL url = new URL(sURL); DU;]Q:r{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zRe0z2
httpConnection.setRequestProperty("User-Agent","NetFox"); =/zQJzN
String sProperty = "bytes="+nStartPos+"-"; NWKD:{
httpConnection.setRequestProperty("RANGE",sProperty); 5vS'Qhc
Utility.log(sProperty); QPBf++|
=~R0U
77)C`]0(
InputStream input = httpConnection.getInputStream(); aUd633
//logResponseHead(httpConnection); 3c6<JW
n.XT-X^
3iY`kf
byte[] b = new byte[1024]; 5^%FEZ&Sp
int nRead; -`rz[";n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) AR&u9Y)I
{ HIF.;ImG^
nStartPos += fileAccessI.write(b,0,nRead); |`,%%p|T%
//if(nThreadID == 1) A6-JV8^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uHy^ Bq
} c: _l+CgeH
p`Ax)L\f
,KZ_#9[>
Utility.log("Thread " + nThreadID + " is over!"); :c c#e&BO
bDownOver = true; ni9/7
//nPos = fileAccessI.write (b,0,nRead); ujHqwRh
} 94H 6`
catch(Exception e){e.printStackTrace ();} 1XwbsKQ}
} uQrD}%GI
} N{f RZN
I:[3x2H
R\)pW9)
//打印回应的头信息 =p$1v{L8
public void logResponseHead(HttpURLConnection con) @ 3FTf"#Y
{ c_+}`
for(int i=1;;i++) 5_{C \S`T
{ LC/6'4}_
String header=con.getHeaderFieldKey(i); K`D>G<
if(header!=null) :4/RB%)"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a*!wiTGf
Utility.log(header+" : "+con.getHeaderField(header)); "\Z.YZUa\
else (m25ZhW
break; Y0 Ta&TYZ0
} 3`$-
} +,f|Y6L<
g&) XaF[!
*#w+*ywVZH
public void splitterStop() w>J|416
{ .9PPWY;H
bStop = true; `~F=
} EE=!Y NP]
]^$3S
=E,^ +`M
} 1!~=8FTv
Qk*`9
ssUWr=mD
/* k|'{$/n
**FileAccess.java gDa}8!+i
*//文件访问(定位，写) HM/2/ /
package NetFox; vlY83mU.
import java.io.*; |VQ17*4ff1
Y/?V%X
6w|s1!Bl
public class FileAccessI implements Serializable{ _o`+c wc
Bf1,(^3XH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z9,-FO{#3-
RandomAccessFile oSavedFile; ^}fc]ovV
long nPos; B+:/!_
V{+'(<SV
LVP2jTz
public FileAccessI() throws IOException <[Oe.0SGu
{ 6}4?,r
this("",0); GCm(3%{V%(
} BJC$KmGk
"NWILZwEV
kCRfO}wt3
public FileAccessI(String sName,long nPos) throws IOException cuzU*QW"g
{ tqbYrF)
oSavedFile = new RandomAccessFile(sName,"rw"); :+#$=4
this.nPos = nPos; i7D[5!
oSavedFile.seek(nPos); F#Y9 @E
} d^h`gu~3
2[} O:
c[VVCN8dA
public synchronized int write(byte[] b,int nStart,int nLen) I[nSf]Vm>
{ XNbeYj
int n = -1; !r^fX=X>'
try{ 8_$[SV$q
oSavedFile.write(b,nStart,nLen); %[S-"k
n = nLen; 'aV])(Wm>
} Uzh#zeZ`<
catch(IOException e) Ln+;HorZ]
{ '_ZiZ4O
e.printStackTrace (); xB4}9zN s
} !#&`1cYX
GY`mF1b
;*(i}'
return n; 2`dKnaF|
} _p*a`,tK
i8w/a
S$N!Dj@e;
} M:M"7>:
f/PqkHF
E4N/or
/* ,tTq25~H\
**SiteInfoBean.java 1R.|j_HYy
*/ /6y9u}
package NetFox; _.%U}U
{k}$L|w
I3qTSX-
public class SiteInfoBean { +lplQh@RB
c/lT S
3d`u!i?/
private String sSiteURL; //Site's URL N&yr?b'!-*
private String sFilePath; //Saved File's Path HT:V;?"
private String sFileName; //Saved File's Name ;e)`Cv
private int nSplitter; //Count of Splited Downloading File nV:RL|p2jw
W"Tj.oCUG
?WP*At0
public SiteInfoBean() 4iDqd
{//nSplitter的缺省值为5 e_YTh^wU
//default value of nSplitter is 5 8kLHQ0pmu
this("","","",5); oTJ^WePZQ
} f"z;'
OF}."a
vRh)o1u)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7NvnCs
{ r$:hiE@
sSiteURL= sURL; dv Vz#
sFilePath = sPath; x7xMSy
sFileName = sName; 5?Ukf$)x
this.nSplitter = nSpiltter; %Yt;)q3U
Kzx` E>,z'
x1h&`QUP
} Zi?:< H}
"$/1.SX;]
[<|$If99\
public String getSSiteURL() 6p9 {z42
{ hSz_e
return sSiteURL; Eunmc
} h1H$3TpP
;F_P<b 2
"ql$Rz8
public void setSSiteURL(String value) OdpHF~(Y/
{ u#y#(1 =
sSiteURL = value; Qz89=#W
} /'/i?9:
18Vn[}]"
FJ{/EloF
public String getSFilePath() =W&m{F96
{ +cbF$,M4
return sFilePath; +|x{?%.O
} .SLpgYFL{
A2ufET
L?Ys(a"k
public void setSFilePath(String value) `8r$b/6
{ FUf.3@}
sFilePath = value; `kE7PXqa
} puLgc$?
t(dVd%
6$0<&')Yb
public String getSFileName() 6i%6u=um3
{ IMncl=1
return sFileName; Dw.I<fns^B
} 4l{$dtKbI
p_ f<@WE
4"H*hKp
public void setSFileName(String value) ZyDNtX%
{ jO/cdLKX(
sFileName = value; :b*7TJ\grN
} BU4IN$d0Po
g$jTP#%b
4lWqQVx
public int getNSplitter() mE5{)<N:C
{ 1Y&W>p
return nSplitter; z9g ++]rkJ
} 934j5D
g1|Pyt{
p"c6d'qe
public void setNSplitter(int nCount) J5HN*Wd
{ [qW%H,_
nSplitter = nCount; J4"A6`O
} {@iLfBh5
} tq~4W% p/
Igmg&
< K!r\^
/* u<uc"KY=
**Utility.java \Cu=Le^
*/ #*/nUbsg
package NetFox; 8b.k*,r>
Wh..QVv
ZzNHEV
public class Utility { |'1.ajxw
=.;ib6M
?4U4o<
public Utility() Ahl&2f\
{ 0?8>{!I
fMFkA(Of^
yQUrHxm
} H390<`
]o]`X$n
//线程睡眠 $)"T9$>$
public static void sleep(int nSecond) '%t$mf!nV
{ v~Dobk/n
try{ [KYq01cj
Thread.sleep(nSecond); WN{8gL&y
} ;Us6:}s
catch(Exception e) Yg '(
{ .<>t2,Af
e.printStackTrace (); -s2)!Iko&
} Qc-W2%
} 7F>]zrbK
72xf|s=
//日志 9C,gJp}P
public static void log(String sMsg) *~6]IWN`
{ Bf00&PE;
System.err.println(sMsg); 8A]8yX =
} EH2):
!gLJBp
.O0eSp|e
public static void log(int sMsg) uGXvP(Pg'
{ W`_Wi*z4
System.err.println(sMsg); rtvLLOIO
} g~K-'Nw
} mD +9/O!
~oSA&v4V
:%mlsNw
/* wjX0r7^@
**TestMethod.java nY1PRX\
*/ -M]/Xv]
package NetFox; ^8oN~HLZ
AX@bM
;MYK TE>m
public class TestMethod { x?{l<mc
E"BW-<_!
X%*BiI
public TestMethod() ]OKKR/:
{ ///xx/weblogic60b2_win.exe epk C'
try{ 0[ n;ZL~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p|;#frj
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,bzgjw+R5
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^|rzqXW
fileFetch.start(); <4?(|Vh[m]
} cru&nH*O^
catch(Exception e){e.printStackTrace ();} dXt@x8E
}/NL"0j+4
m7>)p]]
} 9ys[xOh WM
**9[e[(X
=1B;<aZH!
public static void main(String[] args) K^AIqL8
{ Sf`?j
new TestMethod(); i2O$oHd
} ]tK<[8Y
} ,8p-EH
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