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)); HnArj_E
} <y8oYe_!
for(int i=0;i<nEndPos.length-1;i++) ntLEk fK{
{ .8W-,R4
nEndPos = nStartPos[i+1]; y?a71b8m
} q{`1[R
nEndPos[nEndPos.length-1] = nFileLength; O|sk"YXF
} PwW$=M{\.
} cW>=/
Eu' ;f_s
h,FU5iK|
//启动子线程 6HZtdRQF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kJmwR
for(int i=0;i<nStartPos.length;i++) 1q(Qr h
{ QOEi.b8r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^+Nd\tp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9vP;i= fr
nStartPos,nEndPos,i); .O"a:^i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CIMI?
fileSplitterFetch.start(); ;&<N1
} 2Snb+,o2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mH\zSk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C]2-V1,ZX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RAl/p9\A+
nEndPos = " + nFileLength); ic`BDkNO
// fileSplitterFetch[nPos.length-1].start(); rwJU;wy
4_5f4%S
M>Q ZN
//等待子线程结束 S>I` y]qlR
//int count = 0; g,]o+nT
//是否结束while循环 EtzSaB*|
boolean breakWhile = false; 1SztN3'q
OGg\VV'
=V|jd'iwx
while(!bStop) pC:YT/J
{ ;Tr,BfV|Bf
write_nPos(); D(ItNMcKu
Utility.sleep(500); ,V,mz?d^9
breakWhile = true; `$Rgn3
:0:Tl/))
YA,~qT|
for(int i=0;i<nStartPos.length;i++) 3as=EYm
{ Fn.JtIu
if(!fileSplitterFetch.bDownOver) vY_[@y
{ :=y5713
breakWhile = false; 'y;Kj
break; N<i5X.X
} %?+vtX
} 7qyPI
if(breakWhile) y@l&B+2ks
break; 0Qa0
AC1RP`c
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//count++; =gI41Y]
//if(count>4) OiQf=Uz\
// siteStop(); tgKr*8t{
} sR1_L/.
]uox ^HC
>fWGiFmlk
System.err.println("文件下载结束！"); '27$x&6>S
} cZ_)'0
catch(Exception e){e.printStackTrace ();} 0\:=KIY.
} }qso} WI
6}-No
y#B=9Ri=z
//获得文件长度 `;Tf_6c
public long getFileSize() 6=]Gom&S
{ N\*oL*[j
int nFileLength = -1; v|(]u3=1_
try{ iY/2 `R
URL url = new URL(siteInfoBean.getSSiteURL()); RJ@79L*#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Mc.{I"c@
httpConnection.setRequestProperty("User-Agent","NetFox"); I :<,9.
lo>9 \ Po
3eE=>E4,
int responseCode=httpConnection.getResponseCode(); [tkx84M8
if(responseCode>=400) 9k ~8n9
{ 5NZuaN
processErrorCode(responseCode); ,Suk_aX>
return -2; //-2 represent access is error ?pZU'5le`
} G^t)^iI"'
56z>/`=
FTCIfW
String sHeader; Kj4BVs
J[:#(c&c!1
$B-/>Rz
for(int i=1;;i++) se %#U40*
{ QIMd`c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |1!fuB A
//Utility.log(in.readLine()); ij0I!ilG4
sHeader=httpConnection.getHeaderFieldKey(i); v_5qE
if(sHeader!=null) sPi
{ "O>~osj
if(sHeader.equals("Content-Length")) P^<3 Z)L
{ ,;}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ):PN0.H8
break; "<0!S~]
} bs|gQZG
} y[$UeE"0
else }&=l)\e
break; `3\U9ZH23
} qY8; k #
} :G 5p`;hGo
catch(IOException e){e.printStackTrace ();} )8oyo~4?
catch(Exception e){e.printStackTrace ();} 5V/&4$.U!
u;$qJjS N
ks.p)F>]
Utility.log(nFileLength); T3oFgzoO
[]@@
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return nFileLength; Ne+Rs+~4
} ]\fHc"/
o(e(|k {
t`Bk2Cc)+
//保存下载信息（文件指针位置） 9e`};DE
private void write_nPos() #9TL5-1y
{ (nLzWvN
try{ @xdtl{5G
output = new DataOutputStream(new FileOutputStream(tmpFile)); dHx4yFS
output.writeInt(nStartPos.length); #WG}"[ ,c
for(int i=0;i<nStartPos.length;i++) cZN<}n+q
{ uB"B{:Kz
// output.writeLong(nPos); +ZjDTTk
output.writeLong(fileSplitterFetch.nStartPos); #@HlnF}T
output.writeLong(fileSplitterFetch.nEndPos); )8^E{w^D}
} bJMsB|r
output.close(); @Pc7$qD%
} -%J9!(
catch(IOException e){e.printStackTrace ();} q'S[TFMNE
catch(Exception e){e.printStackTrace ();} UucX1%
} vh.8m$,
$&.(7F^D
-_9*BvS]R
//读取保存的下载信息（文件指针位置） tLKf]5}f
private void read_nPos() &<*M{GW'&
{ -`5]%.E&8
try{ ^/?7hbr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K@n-#
int nCount = input.readInt(); R(0[bMr3Q
nStartPos = new long[nCount]; 5GAW3j{
nEndPos = new long[nCount]; <[ dt2)%L>
for(int i=0;i<nStartPos.length;i++) '['%b
{ &I ~'2mpk
nStartPos = input.readLong(); x_O:IK.>
nEndPos = input.readLong(); J1(SL~e],
} }f;TG:6
input.close(); pWE(?d_M{G
} {w3<dfJ
catch(IOException e){e.printStackTrace ();} 56YqYu.
catch(Exception e){e.printStackTrace ();} j9c:SP5
} Y*9vR~#H
ZL0Vx6Ph
K+/wJ9^B
private void processErrorCode(int nErrorCode) 7p'pz8n`X
{ &^&0,g?To
System.err.println("Error Code : " + nErrorCode); e%:vLE 9
} p/0dtnXa(
|a])o
wG:RvgX}
//停止文件下载 y)|d`qC\
public void siteStop() MA9E??p3\
{ T*B`8P
bStop = true; VG7#C@>Z
for(int i=0;i<nStartPos.length;i++) _t]Q*i0p
fileSplitterFetch.splitterStop(); _T.`+0UV
+Goh`!$Rj9
_0 43,
} 7?g({]
} tol-PJS}
//负责部分文件的抓取 HrLws95'
**FileSplitterFetch.java {TJ"O
*/ D dwFKc&
package NetFox; ;K l'[~z
w$s6NBF7
;L76V$&
import java.io.*; oJ5n*[qUI
import java.net.*; PY4">~6\i
9:%')M&Q
jEx8G3EL
public class FileSplitterFetch extends Thread { Zd)LVc[
qldm"Ul
pdN8hJ
String sURL; //File URL MsIaMW_
long nStartPos; //File Snippet Start Position k=d_{2 ~
long nEndPos; //File Snippet End Position 6Yva4Lv
int nThreadID; //Thread's ID iX2exJto
boolean bDownOver = false; //Downing is over [KGj70|~
boolean bStop = false; //Stop identical , DuyPBAms
FileAccessI fileAccessI = null; //File Access interface ]n1#8T&<*z
ae3 Gn}tf
to_dNJbv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException lGT[6S\as
{ wmbG$T%k
this.sURL = sURL; Ao\OU}
this.nStartPos = nStart; ~_CZ1
this.nEndPos = nEnd; WuWOC6^
nThreadID = id; @QpL*F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vfDX~_N
} 8rBa}v9
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ZZ}HgPZ
public void run() Y*jkUQ
{ I+Qt5Ox
while(nStartPos < nEndPos && !bStop) $WW7,
{ B&!>& Rbx
=yJc pj
bjwl21;{
try{ F`gK6;zp
URL url = new URL(sURL); #Ph8?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9O&MsTmg$
httpConnection.setRequestProperty("User-Agent","NetFox"); W`#E[g?]
String sProperty = "bytes="+nStartPos+"-"; -idbR[1{?
httpConnection.setRequestProperty("RANGE",sProperty); LDo~
Utility.log(sProperty); A)SnPbI-p
+4IaX1.
/_(l:q^
InputStream input = httpConnection.getInputStream(); $Vs5d=B
//logResponseHead(httpConnection); CC`#2j
(A_H[xP
XGnC8Be{4
byte[] b = new byte[1024]; @&E7Pg5
int nRead; |ns9ziTDI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W-1Ub |8C
{ T-oUcuQB
nStartPos += fileAccessI.write(b,0,nRead); @[$q1Nm
//if(nThreadID == 1) R6o07.]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]K5j(1EN
} 1OK~*=/4
i94)DWZ^
i#U_g:~wC
Utility.log("Thread " + nThreadID + " is over!"); !r*JGv=
bDownOver = true; =p8iYtI
//nPos = fileAccessI.write (b,0,nRead); 1$yS Ii
} TDR#'i
catch(Exception e){e.printStackTrace ();} {4R;C~E8
} 2F,?}jJ.K
} G@dw5EfF9
&:C(,`~
t/x]vCP,2D
//打印回应的头信息 1[Jv9S*f/
public void logResponseHead(HttpURLConnection con) i@YM{FycX
{ Oh=Kl3xs
for(int i=1;;i++) / Kj;%
{ 3SF J8
String header=con.getHeaderFieldKey(i); bFIv}c+;
if(header!=null) eGrxS;NY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =~$)Ieu
Utility.log(header+" : "+con.getHeaderField(header)); 'yAHB* rQR
else y[f6J3/
break; g.Kyfs4`
} LgSVEQb6\|
} C #@5:$
x@VZJrQQ
v kW2&
public void splitterStop() N!af1zj
{ l\=He
bStop = true; Zdu8axK:
} HO8x:2m
Oufdi3h
B}h8c
} yuB\Z/
YksJ$yH^
0yKPYA*j
/* EK^["_*A
**FileAccess.java 1GgG9I
*//文件访问(定位，写) PKNpR
package NetFox; Dj{t[z]$k
import java.io.*; sCRmLUD
! lm0zR
ulY<4MN
public class FileAccessI implements Serializable{ 'miY"L:| O
C@FX[:l@-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E1rxuV|9
RandomAccessFile oSavedFile; l*4_
long nPos; [-x]%
q+Qrc]>-f
\kksZ4,
public FileAccessI() throws IOException cvv(OkC
{ GH6ozWA
this("",0); 92Df.xI}
} A/U,|
A^hFRAg4
JNgl
public FileAccessI(String sName,long nPos) throws IOException wWUt44:0O
{ J@pCF@'
oSavedFile = new RandomAccessFile(sName,"rw"); K.2l)aRd
this.nPos = nPos; tcS7 @^'
oSavedFile.seek(nPos); E6y ?DXWH
} K9N\E"6ZP
[H2"z\\u
d+:pZ
public synchronized int write(byte[] b,int nStart,int nLen) LIDYKKDJ^
{ n g?kl|VG
int n = -1; niP/i
try{ hiA%Tq?
oSavedFile.write(b,nStart,nLen); ZA/:\6gm
n = nLen; $P%b?Y/
} k'$UA$2d
catch(IOException e) Hb{G RG70
{ XDrNc!XN
e.printStackTrace (); YF<;s^&@u
} /MQI5Djg
a6fqtkZ x
2OJ=Xb1
return n; 7IH^5r
} 8'X:}O/
A~UDtXN*4
h,C?%H+/0Q
} <[mvfw
%4rPkPAtrp
hJ1:#%Qe.
/* g<r'f"^
**SiteInfoBean.java m"Y|xvIA
*/ KD5}Nk)t
package NetFox; l^ aUN
H6PS7g"
j4G?=oDb
public class SiteInfoBean { /*8Ms`
<MH| <hP
m!-,K8
private String sSiteURL; //Site's URL s&7,gWy}BE
private String sFilePath; //Saved File's Path qc-4;m o
private String sFileName; //Saved File's Name \f7Aj>
private int nSplitter; //Count of Splited Downloading File :7+E fu
H,!3s<1
#D-L>7,jA
public SiteInfoBean() -gpF%g`H
{//nSplitter的缺省值为5 BiUOjQC#
//default value of nSplitter is 5 >=_Z\ wA
this("","","",5); )Ekp <2B:0
} nUL8*#p-
Ux Yb[Nbc
8[|RsM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L[Dr[
{ Ox` +Z0)a
sSiteURL= sURL; =A,6KY=E
sFilePath = sPath; MWS=$N)v*
sFileName = sName; 0{PRv./`
this.nSplitter = nSpiltter; mqg[2VTRP
2vit{
k2xOu9ncEj
} /k(KA [bS
~fE6g3
tC=`J%Ik
public String getSSiteURL() 9cu0$P`}5
{ Z~VSWrw3
return sSiteURL; :Sx!jx>W
} JZ5NQ)sX
dX0"h5v1
'Zdjd]
public void setSSiteURL(String value) vElVw. P
{ DJv;ed%x
sSiteURL = value; =jX'FNv#
} .I@jt?6X
fBptjt_
eJB !|
public String getSFilePath() F;mK)Q-
{ (YbRYu
return sFilePath; rH9wRY(
} S1<mO-
AiT&:'<UT
pm-SDp>s
public void setSFilePath(String value) a_UVb'z
{ 0{/P1
sFilePath = value; l;I)$=={=
} U`D.cEMfH
7[wHNJ7)r
>4A~?=
public String getSFileName() Xi]WDH \
{ cC_L4
return sFileName; tH_e?6]
} @?A39G{
R0R Xw
'Jb6CRn
public void setSFileName(String value) S+Aq0B<
{ wL'tGAv
sFileName = value; [/}y!;3iXM
} *[Ld\lRj
NzmVQ-4
nwk66o:|
public int getNSplitter() AHq;6cG
{ &R54?u^A
return nSplitter; vV.TK_y
} %z6.}4h
oJ cR)H
nDh]: t=
public void setNSplitter(int nCount) etX&o5A
{ =(f+geA"hm
nSplitter = nCount; [TAW68f'
} ~RV>V*l
} m@hmu}qz-
&C eG4_Mi
a D*
/* U2*g9Es
**Utility.java uaMf3HeYV
*/ -_bHLoI
package NetFox; &+?JY|u
oyGO!j
pu(a&0
public class Utility { )P:r;a'
6N}>@Y5
~+1t3M e
public Utility() *xEcX6ZHX
{ H[ 6L!
g">E it*[
)$#]h]ac
} 'iM;e K
<#U9ih 2
//线程睡眠 ;-=Q6Ms8
public static void sleep(int nSecond) O2|[g8(_F
{ z~TG~_s
try{ {*VCR
Thread.sleep(nSecond); :` >|N|i
} b[Z5:[@\#
catch(Exception e) =HT:p:S
{ L-}>;M$Y)
e.printStackTrace (); 2s{PE
} 0h~Iua5
} yUb$EMo\
xtef18i>
//日志 yoKl.U"&
public static void log(String sMsg) 8r^~`rL
{ $vNz^!zgV
System.err.println(sMsg); jd9GueV*(
} p@H]F<
8}m bfuo1
kG:,Ff>
public static void log(int sMsg) 5BvCP
{ #hEN4c[Ex
System.err.println(sMsg); )3_I-Ia
} z4f\0uQ
} 6Q<^,`/T
h+e Oe}
gxEa?QH
/* tETT\y|'
**TestMethod.java uJz<:/rwZ-
*/ YqsN#E3pf
package NetFox; >}#h
d52l)8
t+'|&b][Qi
public class TestMethod { "mbcZ5_
TrxZS_
<3dmY=
public TestMethod() (pBOv:6
{ ///xx/weblogic60b2_win.exe nQuiRTU<
try{ mQmn&:R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o]0v#2l'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D}|PBR
SiteFileFetch fileFetch = new SiteFileFetch(bean); zzsQfI#
fileFetch.start(); '=!@s1;{[;
} L,*KgLG
catch(Exception e){e.printStackTrace ();} v?zA86d_
(are2!Oq
w9I7pIIl
} )ndcBwQc"
QUL^]6$
c"OBm#
public static void main(String[] args) (~F{c0\C
{ >$=-0?.
new TestMethod(); :'aT4
} ]M AB
} ,1'9l)zP
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