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)); |BYRe1l6l
} ykJ>*z
for(int i=0;i<nEndPos.length-1;i++) $Kd>:f=A
{ 4e
nEndPos = nStartPos[i+1]; Lj7AZ|k
} ^^Vg~){4
nEndPos[nEndPos.length-1] = nFileLength; tBSW|0
} MfkZ
} T>>c2$ x
Xc.`-J~Il
{G-kNU
//启动子线程 afk>+4q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sRfcF`7
for(int i=0;i<nStartPos.length;i++) zeRyL3fnmb
{ }a/Cro.~4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @]0%L0u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qSQ~D(tO
nStartPos,nEndPos,i); ,u m|1dh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kcEeFG;DQ
fileSplitterFetch.start(); lRQYpc\
} @nf`Gw ;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |uDdHX8T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `u\n0=go
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M%#e1"n
nEndPos = " + nFileLength); P2Y^d#jO
// fileSplitterFetch[nPos.length-1].start(); t,'<gI
h];I{crh
2SLU:=<3
//等待子线程结束 =c7;r]Ol
//int count = 0; [-&Zl(9&
//是否结束while循环 >dT*rH3w
boolean breakWhile = false; kVL.PY\K
}WV:erg`
^Dx&|UwiZa
while(!bStop) w =KPT''!
{ %)n=x ne
write_nPos(); jdBLsy@
Utility.sleep(500); Pz^544\~ou
breakWhile = true; 4P0}+
@ P|y{e6
?Ob3tUz2
for(int i=0;i<nStartPos.length;i++) Ss`LLq0LO
{ W!<U85-#S
if(!fileSplitterFetch.bDownOver) j.YA2mr
{ s`UJ1eJ
breakWhile = false; 28nFRr
break; SAz
} =">NQ)98u
} j!ch5A
if(breakWhile) pJ{Y lS{
break; W>LR\]Ti@
?#fQ~ s
.^g p?
//count++; gFh*eCo
//if(count>4) +h$ 9\
// siteStop(); ;G!q Y
} cZ06Kx..
W8<%[-r
%$mA03[MQ
System.err.println("文件下载结束！"); ZB{EmB0W
} liSmjsk
catch(Exception e){e.printStackTrace ();} =Sv/IXX\di
} <uJ@:oWG7
])!*_
/(LL3cZK
//获得文件长度 `x|?&Ytmf9
public long getFileSize() p#Bi>/C6
{ Z]ONh
int nFileLength = -1; t^L]/$q
try{ 5X+A"X ;C
URL url = new URL(siteInfoBean.getSSiteURL()); g+lCMW\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z{R>
httpConnection.setRequestProperty("User-Agent","NetFox"); U6VKMxSJ
BuwY3F\-O
Xeajxcop#
int responseCode=httpConnection.getResponseCode(); 4R*,VR.K
if(responseCode>=400) `2snz1>!j
{ u&NV,6Fj2[
processErrorCode(responseCode); y)pk6d
return -2; //-2 represent access is error }M+7T\J!
} 6wxs1G
$u.z*b_yy
D]}G.v1
String sHeader; +d>IHpt
.u:GjL'$
a =QCp4^
for(int i=1;;i++) z:;CX@)*
{ ,s(,S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZW}_DT0
//Utility.log(in.readLine()); 8_8l.!~
sHeader=httpConnection.getHeaderFieldKey(i); #F#%`Rv1
if(sHeader!=null) ]tD]Wx%
{ &o*A{
if(sHeader.equals("Content-Length")) l\mPHA23
{ OYd !v`<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `]X>V,
break; kFB
} 0mnw{fE8_
} ]! dTG
else PdCEUh\>y
break; 6pzSp
} s CRdtP
} OH88n69
catch(IOException e){e.printStackTrace ();} Z7#+pPt!
catch(Exception e){e.printStackTrace ();} N0lC0 N?_J
eJSxn1GW
g ?k=^C
Utility.log(nFileLength); . ^u,.
;I*o@x_
TO_e^A#
return nFileLength; `g,..Ns-r
} NgwbQ7)
WM{=CD
p[-O( 3Y
//保存下载信息（文件指针位置） G"6 !{4g
private void write_nPos() y^k$Us
{ KP"+e:a%
try{ Rv=YFo[B
output = new DataOutputStream(new FileOutputStream(tmpFile)); S:Hl/:iV
output.writeInt(nStartPos.length); 74u&%Rj
for(int i=0;i<nStartPos.length;i++) <[phnU^ 8
{ yuVs YV@"
// output.writeLong(nPos); 0erNc'e
output.writeLong(fileSplitterFetch.nStartPos); U(Zq= M
output.writeLong(fileSplitterFetch.nEndPos); 9z0p5)]n>
} Z.WW(C.
output.close(); S 5U;#H
} _&x%^&{
catch(IOException e){e.printStackTrace ();} C}X\|J
catch(Exception e){e.printStackTrace ();} n?Q|)2 2
} .N3mb6#[R
5bIw?%dk(
SKtrtm
//读取保存的下载信息（文件指针位置） -} +[
private void read_nPos() ~dSr5LUD
{ ZG:{[sT
try{ s.#`&Sd>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z{6Z 11|
int nCount = input.readInt(); l.]xB,k
nStartPos = new long[nCount]; h 0|s
nEndPos = new long[nCount]; @c#(.=
for(int i=0;i<nStartPos.length;i++) >usL*b0%
{ *I+Q~4
nStartPos = input.readLong(); b'g )
nEndPos = input.readLong(); ,I9bNO,%JK
} BWNi [^]
input.close(); >eaaaq9B-
} so; ]&
catch(IOException e){e.printStackTrace ();} G5!^*jf
catch(Exception e){e.printStackTrace ();} \^LFkp
} <$YlH@;)`a
Lr+$_ t}r
D=$)n_F
private void processErrorCode(int nErrorCode) #z(]xI)"
{ 6LZCgdS{
System.err.println("Error Code : " + nErrorCode); +mPx8P&%
} -/4P3SG/
Kq!3wb;
}b}m3i1
//停止文件下载 yVfC-Z
public void siteStop() vX>)je5#
{ ta0|^KAA
bStop = true; _GPe<H
for(int i=0;i<nStartPos.length;i++) <%^&2UMg
fileSplitterFetch.splitterStop(); *i,%,O96Nz
Smh,zCc>s
vI?, 47Hj+
} [7-?7mp!B
} h;Qk@F
//负责部分文件的抓取 sT.ss$HY9,
**FileSplitterFetch.java TvM~y\s
*/ 2eogY#
package NetFox; q)GdD==
:3PH8TL
+t.b` U`-
import java.io.*; ?M2J wAK5
import java.net.*; RFGffA&
cNrg#Asen&
54,er$$V
public class FileSplitterFetch extends Thread { ~Ei<Z`3}7"
4| f*eO
Y2TtY;
String sURL; //File URL ,6/V"kqIP
long nStartPos; //File Snippet Start Position u +hX
long nEndPos; //File Snippet End Position ZcsZ$qt^
int nThreadID; //Thread's ID y5r4&~04
boolean bDownOver = false; //Downing is over R_KH"`q
boolean bStop = false; //Stop identical $qiya[&G4
FileAccessI fileAccessI = null; //File Access interface 9sP0D
B~mj 8l4
:s,Z<^5a)g
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~u{uZ(~
{ SM'|+ d
this.sURL = sURL; zA 3_Lx!
this.nStartPos = nStart; kM6 Qp
this.nEndPos = nEnd; NbobliC=
nThreadID = id; e.>P8C<&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #E[0ys1O
} W^Yxny
(Z*!#}z`
~[ jQ!tz
public void run() |pK!S
{ I]575\bA
while(nStartPos < nEndPos && !bStop) ' QG?nu
{ 7pd$\$
txpgO1
pmM9,6P4@
try{ Z;i:](
URL url = new URL(sURL); Dv"9qk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W!X@
httpConnection.setRequestProperty("User-Agent","NetFox"); |4JEU3\$
String sProperty = "bytes="+nStartPos+"-"; 45e~6",
httpConnection.setRequestProperty("RANGE",sProperty); 7v kL1IA
Utility.log(sProperty); s%S
Hz~zu{;{J
g-A-kqo9
InputStream input = httpConnection.getInputStream(); r$1Qf}J3=
//logResponseHead(httpConnection); yevPHN"M
;jXgAAz7
*hx
byte[] b = new byte[1024]; yfSmDPh
int nRead; d$RIS+V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `A>@]d
{ +TJCLZ..
nStartPos += fileAccessI.write(b,0,nRead); M{@(G5
//if(nThreadID == 1) =(Mch~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g(052]
} f 2.HF@
\zkg
BLttb
Utility.log("Thread " + nThreadID + " is over!"); R5D1w+
bDownOver = true; XUYtEf
//nPos = fileAccessI.write (b,0,nRead); pkzaNY/q
} DrR@n~
catch(Exception e){e.printStackTrace ();} WY/}1X9.%
} ?}0,o.
} |N2#ItBbW
>j/w@Fj
f?Lw)hMrA
//打印回应的头信息 KHme&yMq
public void logResponseHead(HttpURLConnection con) ]`K2N
{ `Oa WGZ[
for(int i=1;;i++) sT)CxOV
{ m@c)Xci
String header=con.getHeaderFieldKey(i); rH-23S
if(header!=null) NOva'qk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /7kC<
Utility.log(header+" : "+con.getHeaderField(header)); p'%s=TGwv
else WE?5ehEme
break; ]/Pn EU[
} fex@,I&
} f8~_E
Tbq;h?D
3u=g6W2 F
public void splitterStop() >Ry01G]_/h
{ *pq\MiD/
bStop = true; !a`&O-ye
} N)T}P\l
CrLrw T
^sw?gH*
} EwN}l
0S"MC9beg
s_Sk0}e
/* ;TYBx24vD'
**FileAccess.java K-4PI+qQ\
*//文件访问(定位，写) _b 0&!l<
package NetFox; n S=W1zf
import java.io.*; HfVZ~PP
1#x0q:6
g#bRT*,L
public class FileAccessI implements Serializable{ @dKTx#gZ
s<Ziegmw|g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +>,I1{u%&
RandomAccessFile oSavedFile; m`XHKRp
long nPos; 3BI1fXT4=j
s!J9|]o
R_C)
public FileAccessI() throws IOException _f83-':W6
{ ^('wy};
this("",0); %EH)&k
} F5<Hm_\:
V0@=^Bls
LVGe]lD
public FileAccessI(String sName,long nPos) throws IOException }#fbbtd
{ ]M=&+c>H~
oSavedFile = new RandomAccessFile(sName,"rw"); aN?zmkPpov
this.nPos = nPos; /: "1Z]@
oSavedFile.seek(nPos); a(nlTMfu
} dd;~K&_Q/i
4Z*/WsCv
)7F/O3Tq
public synchronized int write(byte[] b,int nStart,int nLen) 4RO}<$Nx}
{ 4s-!7
int n = -1; e ,(mR+a8
try{ vsPu*[%
oSavedFile.write(b,nStart,nLen); =cI(d ,
n = nLen; P pb\6|*
} fhiM U8(&
catch(IOException e) V gWRW7Se
{ ^q5#ihM
e.printStackTrace (); ?s01@f#
} [,Gg^*umS
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6x`t{g]f,
return n; QRUz`|U
} [0!(xp^
01]f2.5
K-v#.e4
} ^8WRqQdx
)9g2D`a4
|Cv!,]9:r
/* (.:e,l{U%
**SiteInfoBean.java y[;>#j$
*/ /uc>@!F
package NetFox; N~Jda o
r!v\"6:OM
D.:Zx
public class SiteInfoBean { 4hB]vY\T
j2k"cmsKh
wk^B"+Uhy
private String sSiteURL; //Site's URL IGl9g_18
private String sFilePath; //Saved File's Path M`_0C38
private String sFileName; //Saved File's Name J.a]K[ci
private int nSplitter; //Count of Splited Downloading File x2xRBkRg=
V3Bz Mw\9r
Gc?a+T
public SiteInfoBean() _BufO7`.
{//nSplitter的缺省值为5 YK_7ip.a[
//default value of nSplitter is 5 )~>YH*g
this("","","",5); L(-4w+
} 00(\ZUj
VY-EmbkG-t
6ujWNf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m67V_s,7B
{ 10&8-p1/mc
sSiteURL= sURL; [^iN}Lz
sFilePath = sPath; hrk r'3lv
sFileName = sName; wYea\^co
this.nSplitter = nSpiltter; mh%VrAq
z{q`GwW
U{mYTN*:j$
} KI.unP%
*. t^MP
W?&%x(6M
public String getSSiteURL() tQVVhXQ7
{ iZmcI;?u
return sSiteURL; =pNY eR_[
} UKGPtKE<
*~`(RV
h[ ZN+M
public void setSSiteURL(String value) i8p6Xht
{ e-;}366}
sSiteURL = value; JF]JOI6.e
} sOY:e/_F
A/(a`"mK|'
_c07}aQ ],
public String getSFilePath() (FV >m
{ :RYTL'hes
return sFilePath; ceA9){
} }V>T M{
f);FoVa6
MV"=19]
public void setSFilePath(String value) #yen8SskB
{ 4-w{BZuS
sFilePath = value; UiWg<_<t
} =4!mAo}
$G>.\t
]:;&1h3'7
public String getSFileName() jPeYmv]
{ ]9-\~Mwh
return sFileName; 2oW"'43X
} XW9!p.*.U
_F{C\}
zs;JJk^
public void setSFileName(String value) a*;b^Ze`v
{ ?2a$*(
sFileName = value; /reX{Y
} u2I Cl
BUFv|z+H
=a!=2VN9y
public int getNSplitter() & kIFcd@
{ }u|q0>^8
return nSplitter; $]1=\I
} 6*?F@D2&
$>gFf}#C
E^PB)D(.
public void setNSplitter(int nCount) eyaNs{TV
{ llDJ@
nSplitter = nCount; 8t`?#8D}
} 0x7'^Z>-oe
} $kgVa^
e!`i3KYn"
l6B@qYLZ
/* 3$w65=
**Utility.java ^aQ"E9
*/ g}i61(
package NetFox; PH"%kCI:
$( )>g>%
=;k|*Ny
public class Utility { neh(<>
"b[5]Y{ U
@o^Ww
public Utility() ;jPXs
{ <VcQ{F
MDN--p08
BVm0{*-[|
} DlT{`
2:R+tn(F
//线程睡眠 *I'yH8Fcn
public static void sleep(int nSecond) kT?J5u_o
{ v<;Md-<
try{ Jwp7gYZ
Thread.sleep(nSecond); 'S~5"6r
} ~ 1pr~
catch(Exception e) (t.Nk[
{ x"(KBEK~
e.printStackTrace (); edV\-H5<
} 5;S.H#YOpO
} bcR_E5x$
% nIf)/2g
//日志 AS,%RN^.
public static void log(String sMsg) ;=@0'xPEa-
{ -8Xf0_
System.err.println(sMsg); +#By*;BJ
} vy/-wP|1
]9XDS[<2`
SaCh 7 ^
public static void log(int sMsg) :EH=_"
{ /bEAK-
System.err.println(sMsg); G:JR7N$
} k8Xm n6X
} 1cGmg1U;
:LTN!jj
nm+s{
/* -hV*EPQ/
**TestMethod.java ]?)TdJ`
*/ <Qq*p
package NetFox; C>~TI,5a3
/>Nt[o[r
xpI wrJO
public class TestMethod { P$sxr
{T8Kk)L
V:27)]q
public TestMethod() ]~%6JJN7
{ ///xx/weblogic60b2_win.exe Wf<LR3
try{ fLVAKn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `kr?j:g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a>)f=uS
SiteFileFetch fileFetch = new SiteFileFetch(bean); w:l"\Tm
fileFetch.start(); <or2
} W l16`9
catch(Exception e){e.printStackTrace ();} yBRC*0+Vy
m3ff;,
{^'HL
} Mq8L0%j
aP`P)3O6)1
-F92-jBM4
public static void main(String[] args) 66 Tpi![
{ 7?t6UPf
new TestMethod(); ^J d r>@
} v@Ox:wl>
} zT[!o j7
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