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)); :ZrE/3_S
} 8~Avg6,
for(int i=0;i<nEndPos.length-1;i++) hI249gW9
{ ^W}(]jL
nEndPos = nStartPos[i+1]; #J&45
} \H <k
nEndPos[nEndPos.length-1] = nFileLength; Y v22,|:
} &)Y26*(`
} 5`];[M9
6XU1w
qRy<W
//启动子线程 n *Y+y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; , H$1iJ?
for(int i=0;i<nStartPos.length;i++) *htv:Sr
{ VsLlPw{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aNn\URR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?8dd^iX/
nStartPos,nEndPos,i); ;.Dm?J0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v 809/c*
fileSplitterFetch.start(); s'/b&Idf8
} #bk[Zj&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i4"BN,NZ{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L{XNOf3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rO#WG}E<"
nEndPos = " + nFileLength); ="X2AuK%1$
// fileSplitterFetch[nPos.length-1].start(); Z*,Nt6;e
+"8AmN4
;Ohabbj*
//等待子线程结束 =/_tQR~
//int count = 0; #|\w\MJamP
//是否结束while循环 Qe8F(k~k
boolean breakWhile = false; C9+`sFau@
g~,"C8-H
=2-!ay:
while(!bStop) `` !BE"yN
{ |#uA(V
write_nPos(); =Yd{PZ*fR
Utility.sleep(500); kTJz .
breakWhile = true; !{hC99q6
vd0;33$L
zB,Vi-)vH
for(int i=0;i<nStartPos.length;i++) vE4ce
{ 8cN[t.S
if(!fileSplitterFetch.bDownOver) frsqnvm;+
{ mBb;:-5
breakWhile = false; Yfro^}f
break; _wvSLu<q
} w0`aW6t#
} _T[7N|'O
if(breakWhile) a g=,oYn
break; Rwu y!F
}V@ * :3w8
h?cf)L
//count++; fU?P__zU4
//if(count>4) e15_$M;RW
// siteStop(); Atdr|2
} $?voQ&
5G$sP,n
QOb+6qy:3
System.err.println("文件下载结束！"); R<"fcsU
} f8Z[prfP
catch(Exception e){e.printStackTrace ();} V_)G=#6Dy
} (+M]C]
J`uO~W"
sR(or=ub~
//获得文件长度 m6'VMW
public long getFileSize() H83Gx;
{ *OoM[wEY
int nFileLength = -1; v$H=~m
try{ >%x N?%
URL url = new URL(siteInfoBean.getSSiteURL()); 2.xA' \M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nu'r`
httpConnection.setRequestProperty("User-Agent","NetFox"); 1=R6||8ws
e|6kgj3/
G6l:El&
int responseCode=httpConnection.getResponseCode(); *<.{sx^Gk
if(responseCode>=400) +`y{r^xD
{ ihv=y\Jt
processErrorCode(responseCode); ly!vbpE_
return -2; //-2 represent access is error BYhF?
} ao+lLCr
!&8nwOG
I-L52%E]
String sHeader; 7FQ&LF46
i.O670D
A>C&`A=-
for(int i=1;;i++) _zuaImJ0o
{ `a$c6^a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); HUP~
//Utility.log(in.readLine()); p,(gv])ie
sHeader=httpConnection.getHeaderFieldKey(i); Nft~UggK
if(sHeader!=null) 4Z'/dI`
{ >M2~BDZ
if(sHeader.equals("Content-Length")) -'q#u C
{ Z4&,KrV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #pe#(xoI
break; [i"6\p&
} #o>~@.S#:0
} c8@zpkMj/
else E:_m6 m
break; lKtA.{(
} 1KHFzx,
} \3WF-!xe
catch(IOException e){e.printStackTrace ();} .el&\Jt
catch(Exception e){e.printStackTrace ();} :NHP,"
pm)kocG
w)nFH)f
Utility.log(nFileLength); 5c8tH=
Ci?BJ,
QsXy(w#F
return nFileLength; 4@qHS0$
} *VP-fyJp
[Dzd39aKr
t\\oGH
//保存下载信息（文件指针位置） [WfigqY`b*
private void write_nPos() PU& v{gn
{ B4l*]K%
try{ 26e.Hu
output = new DataOutputStream(new FileOutputStream(tmpFile)); `FJ2 ?
output.writeInt(nStartPos.length); 7I#<w[l>k
for(int i=0;i<nStartPos.length;i++) aa-{,X"MF
{ MAv-`8@|
// output.writeLong(nPos); >e'Hz(~'/
output.writeLong(fileSplitterFetch.nStartPos); )o=ipm[
output.writeLong(fileSplitterFetch.nEndPos); E]aQK.
} vzXfJP
output.close(); t)p. $
} \f!j9O9S
catch(IOException e){e.printStackTrace ();} 006qj.
catch(Exception e){e.printStackTrace ();} k=^~\$e
} x>ZnQ6x~m]
O4+a[82
=%i~HDiy
//读取保存的下载信息（文件指针位置） uQ(C,f[6p
private void read_nPos() # $N)
{ E"/r*C+T
try{ dE_d.[!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t.s;dlx[@
int nCount = input.readInt(); *v}3So
nStartPos = new long[nCount]; oe4r_EkYwW
nEndPos = new long[nCount]; #;+ABV
for(int i=0;i<nStartPos.length;i++) '5usPD
{ ]Yw/}GKB
nStartPos = input.readLong(); G`D~OI
nEndPos = input.readLong(); [ Q@rW5,-
} _aaQ1A`p
input.close(); ~;QzV?%
} (m~gG|n4
catch(IOException e){e.printStackTrace ();} lihV!1
catch(Exception e){e.printStackTrace ();} fPpFAO
} +";<Kd-
pXE'5IIN
!GAU?J;<#2
private void processErrorCode(int nErrorCode) (O(X k+L
{ Vm"{m/K0
System.err.println("Error Code : " + nErrorCode); `mt x+C
} I{8sLzA03S
VoGyjGt&
o-}q|tD$<
//停止文件下载 =/Lwprj
public void siteStop() L>ruNw'-K
{ _u]S/X-
bStop = true; ^&|KuI+u
for(int i=0;i<nStartPos.length;i++) c %f'rj
fileSplitterFetch.splitterStop(); o4U[;.?c
Z'<I Is:J
R'z -#*[
} ir?Y>
} K^yZfpa8
//负责部分文件的抓取 bCSgdK
**FileSplitterFetch.java &F 3'tf?
*/ +lNAog
package NetFox; "J=A(w5
-Uo"!o>x|
wvnuE<o8
import java.io.*; NDo>"in
import java.net.*; FSNzBN
LP{@r ic
.wPu #*
public class FileSplitterFetch extends Thread { k@Q>(`
/ygC_,mx
S [=l/3c
String sURL; //File URL T1_qAz+
long nStartPos; //File Snippet Start Position 9x]yu6
long nEndPos; //File Snippet End Position wRCv?D`vV
int nThreadID; //Thread's ID ?3t]9z
boolean bDownOver = false; //Downing is over 5;:964Et
boolean bStop = false; //Stop identical (oG-h"^/
FileAccessI fileAccessI = null; //File Access interface TNj WZ
x9qoS)@CM
= a54
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `*ml/% \
{ fnJ!~b*qo
this.sURL = sURL; YsBOh{Ml
this.nStartPos = nStart; WWtksi,
this.nEndPos = nEnd; ([Da*Tk*
nThreadID = id; h4,S/n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2+'4m#@)
} >$/PfyY7@#
|WUm;o4E`U
9`| ^cL*6
public void run() g+zfa.wQ
{ AfaoFn+
while(nStartPos < nEndPos && !bStop) %AV[vr,
{ ;#+Se,)
(\A~SKEX
iqAME%m
try{ AZ'"Ua
URL url = new URL(sURL); VYAz0H1-_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QZO9CLX 8k
httpConnection.setRequestProperty("User-Agent","NetFox"); J.g4I|{
String sProperty = "bytes="+nStartPos+"-"; qCUn. mI
httpConnection.setRequestProperty("RANGE",sProperty); vbMt}bM(GD
Utility.log(sProperty); Dxx`<=&g
t)n}S;iD
[Fo"MeH?R
InputStream input = httpConnection.getInputStream(); 5a^b{=#Y
//logResponseHead(httpConnection); w"/RI#7.
24L =v
,f3Ck*M
byte[] b = new byte[1024]; =(\xe| Q
int nRead; ](tv`1A,Wd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O~L/>Ya
{ iI@m e=
nStartPos += fileAccessI.write(b,0,nRead); {T(z@0Xu
//if(nThreadID == 1) 0%OV3`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JQdeI+
} okSCM#&:[2
jv5Os-
jC3)^E@:"
Utility.log("Thread " + nThreadID + " is over!"); 8r-'m%l
bDownOver = true; <}z,!w8
//nPos = fileAccessI.write (b,0,nRead); nLjc.Z\Bl
} .`5BgX7W
catch(Exception e){e.printStackTrace ();} 4.o[:5'
} #CcWsI>+w>
} :,*{,^2q:
k,M%"FLQ
|j>fsk~
//打印回应的头信息 Xx;4
public void logResponseHead(HttpURLConnection con) !^*-]p/z
{ WY`hNT6M
for(int i=1;;i++) -'F? |
{ [(D^`K<b
String header=con.getHeaderFieldKey(i); xJ[Xmre
if(header!=null) %$3)xtS6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ix1[ $9
Utility.log(header+" : "+con.getHeaderField(header)); /'WIgP
else )<8f3;qd
break; ^cz;UQX~}
} cUPC8k.1
} mO~A}/je
O%R*1 P9
"<LVA2v;
public void splitterStop() |8<P%:*N
{ 0//B+.#
bStop = true; tc4"huG
} TLC&@o :
qt&zo5
c=Y8R/G<
} " +n\0j;
@!MhVNS_<
/'uFX,
/* SPEDN}/^
**FileAccess.java [ta3sEPjs
*//文件访问(定位，写) @ApX43U(
package NetFox; ),#hBB`ZA
import java.io.*; @2eV^eO9
tMQz'3,X
InCo[ 8SI
public class FileAccessI implements Serializable{ LjOHlT'
di,?`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Xj+oV
RandomAccessFile oSavedFile; L^Q q[>
long nPos; XDM~H
'<v_YxEn
!/|^ )d^U
public FileAccessI() throws IOException `kERM-@A
{ xw5LPz;B
this("",0); M!nwcxB!
} leMcY6
-g`3;1EV^
Z-wvdw]$
public FileAccessI(String sName,long nPos) throws IOException ZZJXd+Q}
{ 0*-nVC1
oSavedFile = new RandomAccessFile(sName,"rw"); RxZ#`$F
this.nPos = nPos; ))z1T8
oSavedFile.seek(nPos); 48 |u{
} e_{!8u.+
XnCrxj
Js("H
public synchronized int write(byte[] b,int nStart,int nLen) ;?`l1:C5)
{ ?5yj</W
int n = -1; gY=Ry=w9
try{ JMa[Ulz
oSavedFile.write(b,nStart,nLen); rDvz2p"R
n = nLen; ; Da[jFP
} us,1:@a)a
catch(IOException e) tm[e?+Iq
{ y!;PBsU%Sx
e.printStackTrace (); `4N{x.N
} ~BJ~]~0P`
['l.]k-b}
Uq8=R)1<|d
return n; @T6Z3Zj}
} G>q16nS~KP
5HAIKc
Q|+g= |%^
} <y30t[.E6
{ylhh%t4hi
Zagj1OV|
/* A7SE>e>
**SiteInfoBean.java aTx*6;-PH
*/ 3>I
package NetFox; 8iDg2_l`G
-<0PBl
Q:#Kt@W
public class SiteInfoBean { V&>\U?q:
<P"4Mk7`s
;& PK6G
private String sSiteURL; //Site's URL $^1L|KgXp
private String sFilePath; //Saved File's Path KOQ9K
private String sFileName; //Saved File's Name DIU9Le
private int nSplitter; //Count of Splited Downloading File eyLVu.
+uY)MExs2
7?O~3
public SiteInfoBean() az=(6PX
{//nSplitter的缺省值为5 U.[?1:v
//default value of nSplitter is 5 lv*fK
this("","","",5); V>2mzc
} 0B;cQSH!q
s, 8a1o
G\U'_G>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b35Z1sfD j
{ SB3=5"q
sSiteURL= sURL; ?<#2raH-
sFilePath = sPath; UOg4E
sFileName = sName; H%*<t}
this.nSplitter = nSpiltter; P(Fd|).j$
RRBokj)]
+&p}iZp
} TBzOz:k
q~K KN /N
=c>w
public String getSSiteURL() guC7!P^
{ 4p%=8G|
return sSiteURL; rkW2_UTZE
} !w[io;
%!>~2=Q2*
_Wjd`*
public void setSSiteURL(String value) p FkqDU
{ [AZN a
sSiteURL = value; _IK@K6V1
} j9=QOq
y@L-qO+{&
8jnz;;|
public String getSFilePath() NNt,J;
{ c<8RRYs
return sFilePath; JBsHr%!i
} gD\ =
t1I` n(]n
-[I}"Glz:
public void setSFilePath(String value) 06&:X^
{ cN{-&\ 6L
sFilePath = value; 1f"LAs`%
} ZXf^HK
$1CAfSgKw
G(puC4 "&
public String getSFileName() =HF||p@
{ {iv!A=jld
return sFileName; r#K;@wu2
} |Q'l&Gt6
`+!GoXI
0wzq{~\{=_
public void setSFileName(String value) S'I{'jP5
{ +;}XWV
sFileName = value; f8Xe%"<
} Z]I[?$y
jZm57{C#*?
}a(x L'F
public int getNSplitter() Y2DR oQ
{ 2#n4t2p
return nSplitter; K,>D%mJ
} e6n^l$'
%EZG2JjO)
?]fd g;?@
public void setNSplitter(int nCount) !~{AF|2f
{ 1!x-_h}
nSplitter = nCount; dJhT}"x
} EcA@bZ0
} ?w}E/(r
QPi]5z?
:(,Eq?
/* axl!zu*
**Utility.java CL^MIcq?
*/ FuZ7xM,
package NetFox; 4s!rrDN
#!?5^O
0YsC@r47wL
public class Utility { {-sy,EYcw
Q1G?e,Q
He4sP`&I
public Utility() :eK;:pN
{ 5N:THvh6o
L`yyn/2>
y7I')}SC
} QY<{S&k9
vG'JMzAm
//线程睡眠 CW(]6s u{
public static void sleep(int nSecond) rNL*(PN}lO
{ U!"+~d)
try{ ,6Kx1 c
Thread.sleep(nSecond); 9HOdtpQOV
} $18|@\Znj
catch(Exception e) Q?GmSeUi
{ !s;+6Sy
e.printStackTrace (); {*8'bNJ
} ! K~PH
} "YlN_U
U@<>2
//日志 Ix,`lFbH
public static void log(String sMsg) N#')Qz:P
{ 8J:6uO c|
System.err.println(sMsg); %Dg]n4f
} #Nt?4T<
C:n55BE9
Q(-:)3g[aL
public static void log(int sMsg) Vwp fkD`
{ [@OXvdTV
System.err.println(sMsg); (hefpqpi
} #\G{2\R
} zof>S>5>R7
A f@IsCOJ
]3_oT^$:
/* )MFa~/x
**TestMethod.java ~n#rATbxf
*/ W@w#A]
package NetFox; o$4n D#P3
Ed3 *fY
bz[+g,e2oA
public class TestMethod { +Io[o6*
NTk"W!<Cl2
{]~b^=qE$
public TestMethod() uE~? 2G
{ ///xx/weblogic60b2_win.exe j+:q:6=
try{ %+iJpRK)7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8t!/Op?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^tIi;7k
SiteFileFetch fileFetch = new SiteFileFetch(bean); "E;]?s9x
fileFetch.start(); j_E$C.XU{g
} T<\Q4Coth
catch(Exception e){e.printStackTrace ();} 2G8f4vsC[
o$>A;<
" 1YARGu
} tL1"Dt>
u>j:8lhtV
x68$?CD
public static void main(String[] args) C8%Iol
{ 83UIH0(
new TestMethod(); d-g&TSGd
} 2H8,&lY.p
} xX`P-h>V`c
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