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)); 144Y.
} AdX))xgl
for(int i=0;i<nEndPos.length-1;i++) tOwn M1 :(
{ !_QI<=X
nEndPos = nStartPos[i+1]; f|[7LIdh-
} Sj+H{xJi
nEndPos[nEndPos.length-1] = nFileLength; g4K+AK
} 'aSsyD!?<
} [xS7ae
s~M4.06P
+^.Yt0}
//启动子线程 umYsO.8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]so/AdT9hA
for(int i=0;i<nStartPos.length;i++) m`yvZ4K!
{ >m%_`68
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y>o:5':;'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n,N->t$i
nStartPos,nEndPos,i); ,d"T2Hy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &<&tdShI
fileSplitterFetch.start(); jqUVERbc
} i~@gI5[k+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^e:z ul{;]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }:m#}s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l6M?[
nEndPos = " + nFileLength); ,=/9Ld2w9
// fileSplitterFetch[nPos.length-1].start(); ,Py\Cp=Dw
Sd+5Uf`
qv!(In>u
//等待子线程结束 K#3^GB3P
//int count = 0; :1'
//是否结束while循环 L+t / E`
boolean breakWhile = false; ]U?nYppV
T(!1\TB
*zrT;jG
while(!bStop) m&)/>'W
{ rH}|~
write_nPos(); $LP(\T([
Utility.sleep(500); _i=*0Q
breakWhile = true; Z{8%Cln
* #yF`_p
K\xz|Gq
for(int i=0;i<nStartPos.length;i++) V@'Xj .ze
{ l@`k:?
if(!fileSplitterFetch.bDownOver) di\.*7l?
{ }7PJr/IuF
breakWhile = false; ;,y_^-h;
break; 1+%UZK= K
} .k#PrT1C
} 0'sZ7f<e7
if(breakWhile) dXyMRGRUq
break; 2&hv6Y1
kZ9Gl!g
x{H+fq,M
//count++; 5ibr1zs
//if(count>4) Yy~x`P'g!
// siteStop(); e$LC
} 9Po>laT 5
8mX!mYO3c
+3,7 Apj
System.err.println("文件下载结束！"); Z$z-Hx@%
} vJE=H9E
catch(Exception e){e.printStackTrace ();} \VPw3
} [Rj4=qq=
|W@ ~mrO
*q}yfa35eR
//获得文件长度 ydWr&E5
public long getFileSize() GRc)3 2,
{ L15)+^4n
int nFileLength = -1; s}zR@ !`
try{ :3F[!y3b
URL url = new URL(siteInfoBean.getSSiteURL()); ^EIuGz1@0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0fc;H}B*
httpConnection.setRequestProperty("User-Agent","NetFox"); \Z.r Pq
CvIuH=,
f]*;O+8$LN
int responseCode=httpConnection.getResponseCode(); enk`I$Xx
if(responseCode>=400) ch#)XomN
{ 3MQHoxX
processErrorCode(responseCode); WUS%4LL(
return -2; //-2 represent access is error _'p/8K5)=
} =CzGI|pb
:k9T`Aa]
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String sHeader; .7.G}z1
yp~z-aRa
(-<hx~
for(int i=1;;i++) '`8 ^P
{ o0Teect=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gj|5"'g%
//Utility.log(in.readLine()); B4 bB`r
sHeader=httpConnection.getHeaderFieldKey(i); (XK,g;RoEn
if(sHeader!=null) w,hm_aDq
{ GwO`@-}E
if(sHeader.equals("Content-Length")) .1(_7!m@
{ `yR/M"u6T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bAlty}U
break; \7\sx:!$
} rDl/R^w"
} ll__A|JQ
else B9l~Y/3|
break; <ppdy,j:
} auI`'O`/
} s<*+=aIfu
catch(IOException e){e.printStackTrace ();} e;v7!X
catch(Exception e){e.printStackTrace ();} WOPIF~1v
, S^y>
#-%D(=&I
Utility.log(nFileLength); Q``1^E'
OcB&6!1u
;$tdn?|
return nFileLength; qFVZhBC
} j6s j2D
1<:5b%^c
&wQ<sVQ0$
//保存下载信息（文件指针位置） V 2Xv)
private void write_nPos() Dx\~#$S!=
{ f0eQq;D$K
try{ ,t_&tbf3
output = new DataOutputStream(new FileOutputStream(tmpFile)); tOXyle~C
output.writeInt(nStartPos.length); Ew4D';&;
for(int i=0;i<nStartPos.length;i++) 9z?c0W5x
{ rvx2{1}I
// output.writeLong(nPos); `;Ui6{|
output.writeLong(fileSplitterFetch.nStartPos); !bzWgD7j
output.writeLong(fileSplitterFetch.nEndPos); =nHkFi@D=t
} ZXLAX9|
output.close(); 6Takx%U
} F=&,=r'Q8
catch(IOException e){e.printStackTrace ();} _)@G,E33f@
catch(Exception e){e.printStackTrace ();} pZ $>Hh#
} N?3p,2
i`YZ;L L
2V8"jc
//读取保存的下载信息（文件指针位置） e O~p"d-|
private void read_nPos() `pv
{ `D3q!e
try{ M*'8$|Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;\"5)S
int nCount = input.readInt(); 5%wA"_
nStartPos = new long[nCount]; 9t`yv@.>N
nEndPos = new long[nCount]; ,&Zp^
for(int i=0;i<nStartPos.length;i++) =ZSYg K
{ zvN7aG
nStartPos = input.readLong(); `]]m$
nEndPos = input.readLong(); _G`Q2hf"5
} 2cu2S"r
input.close(); u;%~P 9O
} ;=0-B&+v
catch(IOException e){e.printStackTrace ();} QlVj#Jv;~
catch(Exception e){e.printStackTrace ();} -7oIphJ=\
} 4iSN.nxIZ
/0`Eux\
lhQMR(w^
private void processErrorCode(int nErrorCode) CVY-U|xFY
{ ^69(V LK
System.err.println("Error Code : " + nErrorCode); U4Zx1ieCKH
} >q')%j
%X}D(_
EAh|$~X
//停止文件下载 lX.1B&T9Lr
public void siteStop() +-x+c: IxA
{ ZCK#=:ln
bStop = true; rD6NUS
for(int i=0;i<nStartPos.length;i++) !9qw
fileSplitterFetch.splitterStop(); f% 8n?f3;u
Z3<lJk\Y
P;7[5HFF
} H[R6 ?H@$F
} hQ)?LPUB
//负责部分文件的抓取 W`[7|8(6!
**FileSplitterFetch.java amQiH!}8R
*/ 'mv|6Y
package NetFox; }If,O
$/u.F;
6QHUBm2
import java.io.*; M"-53|#:w\
import java.net.*; #p{8
?t;,Nk`jx
"SKv'*\b
public class FileSplitterFetch extends Thread { !!6@r|.
x wfdJ(&
9e;{o,r@
String sURL; //File URL |+-b#Sa9
long nStartPos; //File Snippet Start Position Nog{w
long nEndPos; //File Snippet End Position JBV 06T_4o
int nThreadID; //Thread's ID 3"HEXJMc
boolean bDownOver = false; //Downing is over # b3 14
boolean bStop = false; //Stop identical C:!&g~{cKi
FileAccessI fileAccessI = null; //File Access interface fX LsLh+~D
B|>eKI
I]#x0?D
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QVb{+`.7
{ BL0xSNE**
this.sURL = sURL; x {Rj2~KC
this.nStartPos = nStart; ? _[q{i{
this.nEndPos = nEnd; H_iQR9Ak7
nThreadID = id; s2tNQtq0W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 HS.eK#:N
} m9'bDyyK
^MWp{E
*P12d
public void run() rv~OfL
{ r-hb]!t
while(nStartPos < nEndPos && !bStop) nS!m1&DeD
{ >)`*:_{
KrTlzbw&p\
vQ5rhRG)E
try{ e{Mkwi+j
URL url = new URL(sURL); PywUPsJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [7{cf`C
httpConnection.setRequestProperty("User-Agent","NetFox"); <UW-fI)X
String sProperty = "bytes="+nStartPos+"-"; n2opy8J#!
httpConnection.setRequestProperty("RANGE",sProperty); tB0f+ wC
Utility.log(sProperty); SphP@J<ONW
}dq)d.c
Q2gz\N
InputStream input = httpConnection.getInputStream(); qz-lQ
//logResponseHead(httpConnection); pW<l9W
EP{ji"/7[
AB.ZmR9|
byte[] b = new byte[1024]; BS?rKtdm(
int nRead; 7U)w\A;~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gp\o|igT
{ %pxHGO=)E
nStartPos += fileAccessI.write(b,0,nRead); %8KbVjn
//if(nThreadID == 1) aqP"Y9l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s8*Q@0
} aO *][;0
#%/0a
'V4B{n7h
Utility.log("Thread " + nThreadID + " is over!"); qwuA[QkPi
bDownOver = true; @i>4k
//nPos = fileAccessI.write (b,0,nRead); KpKZiUQm
} 1?y QjW,
catch(Exception e){e.printStackTrace ();} AHplvksb
} _10I0Z0
} |Mnc0Fgvy,
8$ _8Yva"e
_.GHtu/I
//打印回应的头信息 +qa^K%K
public void logResponseHead(HttpURLConnection con) !$0ozDmD
{ e$-Y>Dd
for(int i=1;;i++) \`?4PQ
{ |zp}u(N
String header=con.getHeaderFieldKey(i); @(m?j1!M
if(header!=null) ZY)&Fam}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )%I62<N,z
Utility.log(header+" : "+con.getHeaderField(header)); 1[(/{CClB
else \2[
break; qD(dAU
} KhNE_. Z
} {G-y7y+E
iB*1Yy0DC
tIW~Ng
public void splitterStop() j[$+hh3:
{ RAoY`AWI
bStop = true; q:P44`Aq
} }ho6
q!) nSD
A{wSO./3
} 5eX+9niY
7;ddzxR4
u/HNXJ7M`9
/* tf{o=X.)
**FileAccess.java <)$JA
*//文件访问(定位，写) q}p (p( N
package NetFox; z4s{a(Tsd
import java.io.*; 26-K:"
bSk)GZyH\d
x3=SMN|a
public class FileAccessI implements Serializable{ 8^qLGUxz
Dp;6CGYl?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kO'NT:
RandomAccessFile oSavedFile; =BgQSs/^c
long nPos; 0?,%B?A8O
BA`K,#Ft7
QzD8 jk#
public FileAccessI() throws IOException +`~kt4W
{ 6F?U:N#<
this("",0); j7=x&)qbx
} x|A{|oFC
6iJ\7
'n7Ld6%1
public FileAccessI(String sName,long nPos) throws IOException 7HEUmKb"
{ -h#9sl->
oSavedFile = new RandomAccessFile(sName,"rw"); lm(k[]@
this.nPos = nPos; \']_y\
oSavedFile.seek(nPos); >?^_JEC6
} Qr]`flQ8
=.6JvX<d1*
e~Z>C>J
public synchronized int write(byte[] b,int nStart,int nLen) cy( WD#^
{ Y~-P9
int n = -1; ck#MpQ!An
try{ ),4cb
oSavedFile.write(b,nStart,nLen); h$a%PaVf
n = nLen; !^(?C@TQ
} S0p[Kt
catch(IOException e) /\UFJ
{ ;+R
e.printStackTrace (); 7Ezy-x2h
} ,&rHBNS
=LojRY
>vc$3%L[$
return n; qBcwM=R3P
} 2sahb#e )
.L))EB
9\a;75a
} W3 2]#M=
>Ef{e6
vFl06N2
/* ~Jx0#+z9V
**SiteInfoBean.java P^& =L&U
*/ {|/y/xYgy'
package NetFox; @hj5j;NHK
0m&W: c
{K>}eO:K
public class SiteInfoBean { NmZowh$M
NVq3h\[X
Q*8=^[x
private String sSiteURL; //Site's URL NaYr$`
private String sFilePath; //Saved File's Path MXGz_Db4'
private String sFileName; //Saved File's Name &WoS(^
private int nSplitter; //Count of Splited Downloading File Ig"QwvR
S[I-Z_S
pn-`QB:{h
public SiteInfoBean() 8;1,saA_9
{//nSplitter的缺省值为5 !t!\b9=
//default value of nSplitter is 5 b[`fQv$G
this("","","",5); 2mfKy9QxO
} O}mz@-Z
%<[U\TL`
pF}WMt
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zJX _EO
{ db0]D\
sSiteURL= sURL; }q D0-
sFilePath = sPath; T~-OC0
sFileName = sName; TjLW<D(i>
this.nSplitter = nSpiltter; Vs@H>97,G
J0O wzO
xty)*$C>
} w4(g]9^Q
I/ V`@*/+
ylwh_&>2
public String getSSiteURL() DRuG5|{I:
{ YK6zN>M}E
return sSiteURL; XX[CTh?O%
} 7dtkylW
s2t9+ZA+s
hmM2c15T5
public void setSSiteURL(String value) :~%{
{ m9 D'yXZ
sSiteURL = value; ]c~W$h+F
} ,AEaW
Auk#pO#
d@e2+3<
public String getSFilePath() 5!*@gn
{ Z[?zaQ$
return sFilePath; 1&#qq*{
} $Z[W}7{pt#
)H|cri~D
c-q=Ct
public void setSFilePath(String value) 8D6rShx =
{ G"D=ozr
sFilePath = value; l[u=_uaYl
} _fE$KaP
$, @,(M`i}
{?hpW+1,#
public String getSFileName() Ic')L*i7O
{ 9L9qLF5 t
return sFileName; g8L{xwx<
} ((cRe6
W}aCU~
"`Mowp*
public void setSFileName(String value) > xie+ ^
{ tv'=xDCp
sFileName = value; 83g$k 9lG.
} s5 ($b
$ n"*scyI
wjc&S'[
public int getNSplitter() w~wg[d
{ "'v^X!"
return nSplitter; T3,}CK#O
} L. DD
+\)a p
cT(=pMt8>
public void setNSplitter(int nCount) 2pmqP-pKd
{ UWo*%&J
nSplitter = nCount; 5VjO:>
} $~)YI/b
} W@FSQ8b>$m
0AD8X+M{P
,jq:%Y[KZ
/* :b`ywSp`
**Utility.java 5N(OW:M
*/ xZ(ryE%
package NetFox; fprP$MbI
ae0t*;~
(d>}Fp
public class Utility { DVz_;m6)
p-XO4Pc6
L25%KGg'o
public Utility() )18C(V-x
{ ToX--w4
Jp"yb`w
o1Nfn'!3/>
} LDh,!5G-M
}*?,&9/_)
//线程睡眠 Fxv5kho
public static void sleep(int nSecond) W[<ZI>mf
{ nZ %%{#T7
try{ bYBEh n
Thread.sleep(nSecond); SZ1yy["
} 6_g:2=6S
catch(Exception e) X.+|o@G
{ 5 BLAa1
e.printStackTrace (); J#xZ.6)
} y;<F|zIm
} K$I`&M(
XNJ3.w:R
//日志 Zygu/M6
public static void log(String sMsg) 6u>]-K5
{ $i@I|y/
System.err.println(sMsg); Y.kgJ #2
} M;9s
*Gul|Lp$<I
]-;MY@
public static void log(int sMsg) spT$}F2n
{ >R}G
System.err.println(sMsg); U^8S@#1Q
} }#h`1 uV
} #Q'#/\5
`j8pgnY>5~
Cy dV$!&mP
/* +w/B3b
**TestMethod.java b/?)_pg
*/ 2N{^V?:
package NetFox; 4W#DLip9
+{0v@6<(02
>&ENrvaJ
public class TestMethod { 0f#xyS 3
?Wc+ J4
[kf6bf@
public TestMethod() +Fb+dU
{ ///xx/weblogic60b2_win.exe RM;Uq>l
try{ =0az5td
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _L+j6N.h1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E0AbVa.
SiteFileFetch fileFetch = new SiteFileFetch(bean); vXm'ARj
fileFetch.start(); \/64Xv3L0
} td7Of(k'
catch(Exception e){e.printStackTrace ();} &0i$Y\g
Fw:_O2
e07u@_'^
} >gDeuye
pu5%$}dBE
IhRdn1&
public static void main(String[] args) zf>*\pZE
{ ;;6$d{
new TestMethod(); Lt ^*L%x
} Gt)ij?~
} udXzsY9Ng
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