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)); +[_gyLN<5b
} ?uig04@3
for(int i=0;i<nEndPos.length-1;i++) $bFgsy*N2
{ #<UuI9
nEndPos = nStartPos[i+1]; U&X.
} ) G|"jFP
nEndPos[nEndPos.length-1] = nFileLength; U1jSUkqb
} I:HV6_/^-G
} $YPQC
PF`:1;PU
8;0^'Qr8
//启动子线程 f}%sO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H(?e&Qkg
for(int i=0;i<nStartPos.length;i++) H6{Rd+\Z
{ M&OsRrq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pLPd[a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Yx!n*+:J
nStartPos,nEndPos,i); Bu':2"7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TG?fUD V
fileSplitterFetch.start(); C`pan /t
} 4L!e=>as"1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [d\#[l_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E}t-N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t:disL&!E
nEndPos = " + nFileLength); 6kC)\uy
// fileSplitterFetch[nPos.length-1].start(); gsi<S6DQ8
A>5S]
F=VoFmF@
//等待子线程结束 a0 qj[+
//int count = 0; 0O_E\- =
//是否结束while循环 Q6xgLx[
boolean breakWhile = false; ;=#qHo9k1%
[|jIC
.N&QW `
while(!bStop) bu;vpNa
{ ]Px:d+wX:
write_nPos(); XGL"gD
Utility.sleep(500); y^3,X_0
breakWhile = true; R4yJ.f
,d5ia4\K
nMeSCX
for(int i=0;i<nStartPos.length;i++) S~}$Ly@
{ fq{I$syY
if(!fileSplitterFetch.bDownOver) 2AmR(vVa"
{ Mg&HRE
breakWhile = false; }WoX9M; 1
break; UX?X]ZYVR
} "1AjCHZ
} R+C+$?4NG
if(breakWhile) JW2W>6Dgv[
break; .ZM]%[4
U24V55ZnI
V.+DP
//count++; omr:C8T>
//if(count>4) -B",&yTV
// siteStop(); XPrY`,kN
} Fv<]mu
Gl=@>Dc%
H#_}^cGPR=
System.err.println("文件下载结束！"); G6f%/m`
} j^:b-:F
catch(Exception e){e.printStackTrace ();} YstXNN4
} bl6':m+
CRP7U
">03~:oA
//获得文件长度 iFY]0@yt
public long getFileSize() H)-L%l|9
{ (gFQK[
int nFileLength = -1; `;R|V
try{ <ihhV e
URL url = new URL(siteInfoBean.getSSiteURL()); Gt?!E6^!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f45x%tha%
httpConnection.setRequestProperty("User-Agent","NetFox"); tPQ2kEW
PsacXZNs\N
\t[ hg
int responseCode=httpConnection.getResponseCode(); ^a: Saq-}
if(responseCode>=400) }x>}:"P;W
{ bwv/{3G,Ys
processErrorCode(responseCode); vr5<LNCLQ
return -2; //-2 represent access is error (8+.#1!*
} hrUm}@d
)WzGy~p8K
3XMBu*
String sHeader; \;4L~_2$q
`@W3sW/^
}S1Z>ZA5
for(int i=1;;i++) O(b"F? w
{ KBp!zSl
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z:W')Nd(
//Utility.log(in.readLine()); u66TrYStG
sHeader=httpConnection.getHeaderFieldKey(i); 56/.*qa
if(sHeader!=null) N^)<)?
{ 7/$nA<qM
if(sHeader.equals("Content-Length")) nI((ki}v
{ vy>];!Cu
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +ytT)S
break; 3uB=L7.
} ^d5gz0d
} vY8WqG]
else ^' edE5
break; /TR"\xQF
} XY&]T'A
} g^Ugl=f,
catch(IOException e){e.printStackTrace ();} /S-/SF:>g
catch(Exception e){e.printStackTrace ();} [J[ysW})W
9u-M! $
lyMJW}T+>
Utility.log(nFileLength); .2 N_?
o+PQ;Dl
8+@1wks
return nFileLength; b7F3]W<`&
} z/Mhu{ttL
9P,A t8V(
3(Hj7d7'}
//保存下载信息（文件指针位置） \{Ox@
private void write_nPos() )j)y5_m
{ VyBJIzs0
try{ >vNk kxWyQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); sWqPw}/3>
output.writeInt(nStartPos.length); v)v{QNQp^
for(int i=0;i<nStartPos.length;i++) a!SR"3 k
{ %BT)oH}
// output.writeLong(nPos); QBN=l\m+
output.writeLong(fileSplitterFetch.nStartPos); $A5B{2
output.writeLong(fileSplitterFetch.nEndPos); soFvrl^Ql+
} J7&.>y1%
output.close(); o{YW
} !/=9VD{U!
catch(IOException e){e.printStackTrace ();} =l?"=HF
catch(Exception e){e.printStackTrace ();} wd2P/y42;;
} W? 6
"OlI-^y
ys~p(
//读取保存的下载信息（文件指针位置） 8Pnqmjjj
private void read_nPos() tOlzOBzR
{ umHs"d
try{ GT1 X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !<['iM
int nCount = input.readInt(); ||"":K
nStartPos = new long[nCount]; eX]9mQ]E
nEndPos = new long[nCount]; ,&O:/|c E
for(int i=0;i<nStartPos.length;i++) MFCbx>#
{ pXh^M{.
nStartPos = input.readLong(); z?IY3]v*z<
nEndPos = input.readLong(); :*w:eKk
} O #p)~V8~
input.close(); %yS`C"ZQ)
} [h2p8i'o
catch(IOException e){e.printStackTrace ();} 2=Vkjh-
catch(Exception e){e.printStackTrace ();} uV*f[l
} 8m13M5r
?L~=Z\H
)=SYJ-ta<
private void processErrorCode(int nErrorCode) \e5,`
{ JVIcNK)
System.err.println("Error Code : " + nErrorCode); (0+GLI8
} OA8b_k~
l,FG:"`Z@
SjNwT[.nr7
//停止文件下载 aF4V|?+
public void siteStop() [XY:MUe
{ 7p"~:1hU
bStop = true; 6m;wO r
for(int i=0;i<nStartPos.length;i++) J?HZ,7X:
fileSplitterFetch.splitterStop(); +-KRp1qq
NiJ?no
gC,0+Y~
} q}7Df!<|
} e4NX\tCpw
//负责部分文件的抓取 a_#eGe>
**FileSplitterFetch.java w!GU~0~3[
*/ )eedfb1
package NetFox; %]= 'Uv^x
CH R?i1e
O<H@:W#k
import java.io.*; L}sm R,
import java.net.*; XH Zu>[
vCH v
1H2u,{O
public class FileSplitterFetch extends Thread { qT-nD}
yrvSbqR
F" #3s=
String sURL; //File URL ju2X*
long nStartPos; //File Snippet Start Position :O@,Z_"
long nEndPos; //File Snippet End Position X:} 5L>'
int nThreadID; //Thread's ID *MyS7<
boolean bDownOver = false; //Downing is over vng8{Mx90*
boolean bStop = false; //Stop identical l8n[8AT1
FileAccessI fileAccessI = null; //File Access interface ]qP}\+:
?RjKP3P
#.t$A9'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u3?Pp[tM<
{ JcALFKLB
this.sURL = sURL; URzE+8m^
this.nStartPos = nStart; <xh'@592
this.nEndPos = nEnd; =ym~= S
nThreadID = id; %+OPas8C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cK}
} V~^6 TS(
_$jJpy
@OL3&R
public void run() d-S'y-V?d
{ h/y}
while(nStartPos < nEndPos && !bStop) :R?| 2l
{ 8@C|exAD`
gt~2Br4
$!3t$-TSD
try{ gSo(PW)
URL url = new URL(sURL); L5N{ie_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e^fKatI1
httpConnection.setRequestProperty("User-Agent","NetFox"); b+#~N>|
String sProperty = "bytes="+nStartPos+"-"; @^4M~F%
httpConnection.setRequestProperty("RANGE",sProperty); k~EPVJh"
Utility.log(sProperty); M&\?)yG
;cHI3V
fyoB]{$p8
InputStream input = httpConnection.getInputStream(); ((IBaEq
//logResponseHead(httpConnection); !iz vY
co%_~xO
L"^366M!
byte[] b = new byte[1024]; J,M5<s[Xqt
int nRead; oP`M\KXau
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I z=w2\r
{ Xs,PT
nStartPos += fileAccessI.write(b,0,nRead); rls#gw
//if(nThreadID == 1) \rnG 1o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T|iF/p]F
} -v+^x`HR
`j"G=%e3.
59J$SE
Utility.log("Thread " + nThreadID + " is over!"); G78j$ ^/0
bDownOver = true; %_=R&m'n`
//nPos = fileAccessI.write (b,0,nRead); fvfVBk#
} o 0 #]EMr
catch(Exception e){e.printStackTrace ();} U$JIF/MO_
} -$|X\#R
} R3!vS+5rR
T-8nUo}i
Y/I6.K3
//打印回应的头信息 aZCT|M1
public void logResponseHead(HttpURLConnection con) `Q^Sm`R
{ KIl.?_61O
for(int i=1;;i++) m-FDCiN>
{ iBW6<2@oZF
String header=con.getHeaderFieldKey(i); RvZ-w$E&?
if(header!=null) T[=cKYp8\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1Moh`
Utility.log(header+" : "+con.getHeaderField(header)); ,%G2>PBt
else LsZ!':LN
break; /+U)!$zm*
} SpiC0
} *K^O oS
#]/T9:
Ca"+t lO
public void splitterStop() S&) >w5*]U
{ g*imswj7
bStop = true; R2ZQBwB
} x#VUEu]8
:%oj'm44!
1>{-wL4rc
} c^gIK1f-
\k-juF80
iC2nHZ*,
/* z(68^-V=:
**FileAccess.java x`l; ;
*//文件访问(定位，写) {YTF]J$
package NetFox; Bzt`9lg
import java.io.*; E}j8p_p
zFQkUgb
ryLNMh
public class FileAccessI implements Serializable{ g'7hc~=
{ 4{{;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RYaofW
RandomAccessFile oSavedFile; (,y/nc=GN
long nPos; xTJ5VgG
?^5*[H
-)+DVG.t
public FileAccessI() throws IOException l<%~w U
{ <s3(
this("",0); n{WJ.Y*
} 9?,.zc^
5FKd{V'
{# _C
public FileAccessI(String sName,long nPos) throws IOException f+~!s 2uw
{ eakIK+-21y
oSavedFile = new RandomAccessFile(sName,"rw"); !jnIXvT1qy
this.nPos = nPos; PdBhX
oSavedFile.seek(nPos); L4Y3\4xXO
} dV
IomJo
#vwXxr
public synchronized int write(byte[] b,int nStart,int nLen) kovzB]
{ JAlsc]XtO9
int n = -1; BQg]$Tr?
try{ B`EgL/Wg[
oSavedFile.write(b,nStart,nLen); Z"T(8>c;g
n = nLen; |:[vpJFK
} 7E)7sd
catch(IOException e) a[l5k
{ mj|9x1U)
e.printStackTrace (); [ Ulo; #P
} e1Hx"7ew_
K a|\gl;V
3vD,hL`&
return n; W RaO.3Q@.
} !2Iwuru
?\r3 _
}`FPe
} 7?] p\`
*4y r7~S5
tpK4 gjf
/* #ySx$WT;
**SiteInfoBean.java !,"G/}'^;
*/ axOy~%%c
package NetFox; ir#^5e@
0VPa;{i/
zy;w07-)
public class SiteInfoBean { f'U]Ik;Jy
E1_4\S*z
hDsORh!i
private String sSiteURL; //Site's URL [G/X
private String sFilePath; //Saved File's Path 3Gv i!h7
private String sFileName; //Saved File's Name &X(-C9'j
private int nSplitter; //Count of Splited Downloading File zt0 zKXw
{NDP}UATw
|;yb *
public SiteInfoBean() KZNyp%q
{//nSplitter的缺省值为5 /d'u1FnA=
//default value of nSplitter is 5 s&</zU'
this("","","",5); k#[s)Ja?s
} !o!04_
T7'$A!c
)_?$B6hf,&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;v\n[
{ Um<vsR
sSiteURL= sURL; -Ma"V
sFilePath = sPath; tEs$+b
sFileName = sName; ZeZwzH)BD
this.nSplitter = nSpiltter; FU3B;Fn^Z(
xd@DN;e
p.|; k%c7
} A[bxxQSP\H
%-CC_R|0$
dz 2d`=`3
public String getSSiteURL() A>puk2s
{ ,V?,I9qf
return sSiteURL; jU$PO\UTk
} Xv:IbM> Qc
wBET.l'd
i|mA/ e3b
public void setSSiteURL(String value) nj$K4_
{ k_B^2=
sSiteURL = value; H"l'E9k.&p
} a{W-+t
kz^G.5n
rge/jE,^~Z
public String getSFilePath() %*nZ,r
{ lOui{QU
return sFilePath; yNL71>w4
} Sj?'T@
4KnDXQ%
,+&j/0U
public void setSFilePath(String value) rpmDr7G
{ DVl:s
sFilePath = value; .$iIr:Tc>
} SH.'E Hd
i}19$x.D`
8Yh2K}
public String getSFileName() f/ZE_MN2
{ f]}F_]
return sFileName; Y$^\D'.k
} 2OTpGl
Ipe;%as#
S SXSgp
public void setSFileName(String value) E_oe1C:
{ U?QO'H5
sFileName = value; rL=$WxdPU
} ;l'I.j
o[6hUX0tN
]!N5jbA@
public int getNSplitter() 7-DC"`Y8e
{ c z|IBsa*
return nSplitter; FQyiIT6
} 2wd(0K}b
; F=_ozWV*
y^Lw7
public void setNSplitter(int nCount) 5kF5`5+Vj
{ _*9Zp1r
nSplitter = nCount; iYf4 /1IG,
} FyEl@ }W
} <_![~n$H
7}Sw(g)o7
Q$%@.@
/* =%L^!//c
**Utility.java d,77L
*/ IjNm/${$
package NetFox; [H6>]&
S,H{\c
s@$AYZm_
public class Utility { >BX_Bou
5+UiAc$
;%1^k/b6t
public Utility() .<.qRq-
{ UTPl7po5D
i]nE86.;
^?2txLv,6
} [3.rG!Na
/y0 )r.R
//线程睡眠 fp7Qb $-A
public static void sleep(int nSecond) 1f=L8Dr
{ }=U\v'%m
try{ Vr*t~M>
Thread.sleep(nSecond); 1}6pq2
} +K?h]v]%
catch(Exception e) p,Z6/e[SI
{ bY>Ug{O;
e.printStackTrace (); )nY/ RO
} +3C S3fTq
} JG[+e*8
3{ci]h`:y8
//日志 1jL?z6S
public static void log(String sMsg) EY>A(
{ '.=Z2O3p
System.err.println(sMsg); g=pDC+
} /Yh8r1^2tZ
P}5aN_v\
*%O1d.,
public static void log(int sMsg) _5zR!|\^
{ -K jCPc
System.err.println(sMsg); *M"wH_cd
} =vFI4)$-
} Cn,jLy
M(|gfsD
AKpux,@xB
/* a-3~HH
**TestMethod.java g5E]o)
*/ U|zW_dj
package NetFox; R9W(MLe58
pQp}HD!-
|"mb59X
public class TestMethod { RwwKPE
T.pPQH__
' 9,}N:p
public TestMethod() @.})nU
{ ///xx/weblogic60b2_win.exe M;(lc?Rv
try{ O7.Is88!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ={fi&j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IOA{lN6
SiteFileFetch fileFetch = new SiteFileFetch(bean); ri:fo'4TO
fileFetch.start(); |9y&;3
} D,hl+P{^K
catch(Exception e){e.printStackTrace ();} NlKnMgt~
T>c;q%A/
sLTf).xh
} DgdW.Kj|IL
.Ybm27Dk
F kWJB>
public static void main(String[] args) ^I0SfZ'Y
{ xWDwg@ P
new TestMethod(); ?*T`a oB
} +z4NxR
} EU+sTe>
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