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)); q9dLHi<1
} l9/:FiJ_
for(int i=0;i<nEndPos.length-1;i++) z8Q"%@
{ 2D([Z-<i
nEndPos = nStartPos[i+1]; ~E=\t9r
} m]IysyFFK
nEndPos[nEndPos.length-1] = nFileLength; (Btv ClZ
} ,fnsE^}.U
} TK>{qxt:=
1]\TI7/n
+#]|)VZ
//启动子线程 ?Ay3u^X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~F#A Pt
for(int i=0;i<nStartPos.length;i++) [.q(h/b
{ HPa|uDVv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LxT rG)4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FBsn;,3<W
nStartPos,nEndPos,i); XLTD;[jO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =J@`0H"
fileSplitterFetch.start(); C>*n9l[M~
} wk02[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #@Ujx_F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;IC'Gq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", DMkhbo&+
nEndPos = " + nFileLength); v3JPE])/
// fileSplitterFetch[nPos.length-1].start(); z/1hqxHl
fQQ|gwVki
A/Khk2-:
//等待子线程结束 .^XHuN&
//int count = 0; y3yvZD
//是否结束while循环 "g `nsk
boolean breakWhile = false; Sl.o,W^
w3#`1T`N
Bp0bY9xLg_
while(!bStop) (^H5EeGV{
{ pN$;!
write_nPos(); w4{y"A
Utility.sleep(500); Lh 9S8EU
breakWhile = true; nC~fvyd<P
/Dw@d,&[
>I-g[*
for(int i=0;i<nStartPos.length;i++) VD#!ztcY'
{ a9[<^
if(!fileSplitterFetch.bDownOver) Bn-J_-%M
{ 1D$::{h
breakWhile = false; hNO)~rt
break; Ofm5[q=
} IIaxgfhZ
} n{=7 yK
if(breakWhile) dwp:iM
break; 4zzlazU
=xBT>h;
Xb+3Xn0}&8
//count++; MOyT< $
//if(count>4) }Z-I2 =]
// siteStop(); `Z8^+AMc
} ! o^Ic`FhS
+\U]p_Fo3
M@~o6^
System.err.println("文件下载结束！"); S*rO0s:
} =43d%N
catch(Exception e){e.printStackTrace ();} Tc,$TCF
} o4'Wr
Oc^m_U8>^
#gI&lO*\gr
//获得文件长度 Wo2v5-
public long getFileSize() F(E<,l2[
{ G)~MbesJ
int nFileLength = -1; #|ddyCg2
try{ UnjNR[=
URL url = new URL(siteInfoBean.getSSiteURL()); fwH`}<o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #~1wv^
httpConnection.setRequestProperty("User-Agent","NetFox"); =Pj@g/25u
@9<S*
s<d!+<
int responseCode=httpConnection.getResponseCode(); m8u=u4z("
if(responseCode>=400) PnJ*Zea
{ blmmm(|~|
processErrorCode(responseCode); u&tFb]1@)
return -2; //-2 represent access is error :4iU^6
} N)P((>S;
nIR*_<ow
yFi6jN#~
String sHeader; 0&Qsk!-B
[5!'ykZ
gjQ=8&i
for(int i=1;;i++) . Jb?]n
{ Fj,(_^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r/^tzH's
//Utility.log(in.readLine()); hMz&JJ&B
sHeader=httpConnection.getHeaderFieldKey(i); =tNzGaWJ
if(sHeader!=null) ^aT;aP^l
{ N-D(y
if(sHeader.equals("Content-Length")) @7)Z
{ s><IykIi
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [h^f%
break; VkWO}
} [pr 9 $Jr
} Pf{`/UlD
else % <^[j^j}o
break; Tt`L(oF
} ^t`f1rGR
} ;FcExg|k
catch(IOException e){e.printStackTrace ();} YN4"O>
catch(Exception e){e.printStackTrace ();} @uoT{E[
aN:HG)$@
ot]>}[
Utility.log(nFileLength); !8we8)7
8g.AT@ ,Q
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return nFileLength; >6XDX=JVI
} FT<H]Nf
W0C{~|e
Xm%iPrl D
//保存下载信息（文件指针位置） B'<!k7Ewy
private void write_nPos() )\D2\1e(c
{ O<4Q$|=&?
try{ yLjV[qP
output = new DataOutputStream(new FileOutputStream(tmpFile)); KlY,NSlQ
output.writeInt(nStartPos.length); 2]2{&bu
for(int i=0;i<nStartPos.length;i++) LjSLg[i
{ qo)Q}0
// output.writeLong(nPos); _yiRh:
output.writeLong(fileSplitterFetch.nStartPos); V+peO
output.writeLong(fileSplitterFetch.nEndPos); Qk+=znJ
} | A3U@>6
output.close(); ? 7/W>
} NY.}uZ
catch(IOException e){e.printStackTrace ();} aB=vu=hF
catch(Exception e){e.printStackTrace ();} uE"5cq'B/
} bK!,Pc<
Y||yzJdC
wTB)v!
//读取保存的下载信息（文件指针位置） *^X#Eb
private void read_nPos() oG+K '(BB
{ gTqeJWX9wP
try{ oK#\HD4U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wEBtre7
int nCount = input.readInt(); rn5"o8|
nStartPos = new long[nCount]; c:3@[nF~
nEndPos = new long[nCount]; L@>^_p$
for(int i=0;i<nStartPos.length;i++) gsLr=
{ |P^]@om
nStartPos = input.readLong(); <Gn8B^~$
nEndPos = input.readLong(); Y8D7<V~Md
} TTeAa
input.close(); 's$A+8;L
} 0q:(-z\S4
catch(IOException e){e.printStackTrace ();} !S~,>,yd
catch(Exception e){e.printStackTrace ();} }5fU7&jA;3
} hZp=BM"bJ
>r;ABz/
,AdusM
private void processErrorCode(int nErrorCode) u^}7Vs .
{ -@YVe:$%b
System.err.println("Error Code : " + nErrorCode); QN)/,=#
} Zx}NFcn
M,.b`1-w
[ED!J~lg8
//停止文件下载 Py|H? ,6=
public void siteStop() =nJOaXR0
{ <{$ev&bQ
bStop = true; %MfGVx}nG
for(int i=0;i<nStartPos.length;i++) 80{#bb
fileSplitterFetch.splitterStop(); w^ixMn~nLF
GCcwEl!K^
S 23S.]r
} >Sc$R0
} Y&?|k'7
//负责部分文件的抓取 xaGVu0q
**FileSplitterFetch.java "\VW.S
*/ JIyBhFI
package NetFox; AzHIp^
%00k1*$
>$7wA9YhL
import java.io.*; L LYHr
import java.net.*; Ck ~V5
Q3B'-BZe
(P E# Y(
public class FileSplitterFetch extends Thread { m&Y;/kr
;whFaQi 4
"/4s8.dw+u
String sURL; //File URL ,^MW)Gf<
long nStartPos; //File Snippet Start Position ka?IX9t\
long nEndPos; //File Snippet End Position pm'@2dT
int nThreadID; //Thread's ID $\YLmG
boolean bDownOver = false; //Downing is over !.;xt L
boolean bStop = false; //Stop identical Gt\K Ln
FileAccessI fileAccessI = null; //File Access interface 2a._?(k_y
XEf&Yd
aBqe+FXp4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0[Xt,~
{ &;6|nl9;
this.sURL = sURL; <?q&PCAn^
this.nStartPos = nStart; O?C-nw6kP
this.nEndPos = nEnd; "oE^R?m
nThreadID = id; 877EKvsiC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >D`fp
} (n":]8}
'f=)pc#&g
:/yr(V{
public void run() V7B=+(xK
{ ?l\gh1{C
while(nStartPos < nEndPos && !bStop) !^>LOH>j
{ 4! Oa4
:Fi%Cef|
Wvut)T
try{ DJ mQZ+{2
URL url = new URL(sURL); O]Ry3j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5I8FD".i
httpConnection.setRequestProperty("User-Agent","NetFox"); lJ2|jFY9
String sProperty = "bytes="+nStartPos+"-"; rB.=f[aX[
httpConnection.setRequestProperty("RANGE",sProperty); a O"nD_7
Utility.log(sProperty); 9z|>roNe
L5zG0mC8
UALg!M#
InputStream input = httpConnection.getInputStream(); Ry8WNVO}R
//logResponseHead(httpConnection); DmXDg7y7s
6uCk0 B|
MuFU?3ovG*
byte[] b = new byte[1024]; Y6;0khp
int nRead; 9h3~;Q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U>L=.\\|
{ _pH6uuB
nStartPos += fileAccessI.write(b,0,nRead); YL9t3]
//if(nThreadID == 1) ,rH)}C<Q+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +QXYU8bYZ
} qa0JQ_?o]
9p[W :)P4d
8JtI&aH-L
Utility.log("Thread " + nThreadID + " is over!"); Wy^[4|6
bDownOver = true; < o'7{
//nPos = fileAccessI.write (b,0,nRead); WnJLX ^;
} ir@N>_
catch(Exception e){e.printStackTrace ();} XftJ= *
} ^+-L;XkeY
} 3Q*RR"3
l9ifUhe
F"m}mf
//打印回应的头信息 9A} kkMB:
public void logResponseHead(HttpURLConnection con) hBfzU\*0H
{ ,8J*S
for(int i=1;;i++) G7_"^r%c9;
{ %8}ksl07
String header=con.getHeaderFieldKey(i); o. V0iS]
if(header!=null) o$blPTN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g]iy-,e
Utility.log(header+" : "+con.getHeaderField(header)); qh(-shZ4Du
else }d~FTre
break; ZTBFV/{
} 1&@wb'MBs.
} #o"HD6e
hml\^I8Q>F
uDE91.pUkr
public void splitterStop() ^pQ;0[9Y0
{ S^Wqa:;
bStop = true; C(t6;&H
} R 6yvpH
{ZsWZJ!
ANpY qV
} SVs~,
dVmAMQk.g
t!=~5YgKs
/* 8{4D|o#O
**FileAccess.java ;DgX"Uzm
*//文件访问(定位，写) 5.K$ X$+7}
package NetFox; }rMpp[
import java.io.*; 2W:?#h3
SE}RP3dF!
}Mb'tGW
public class FileAccessI implements Serializable{ N13;hB<
NK#"qK""k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zS"zb
RandomAccessFile oSavedFile; zRJKIm
long nPos; %qjyk=z+Z
#&2N,M!Q
wyzBkRg.
public FileAccessI() throws IOException yE|} r
{ <,cIc]eX
this("",0); g d}TTe
} WWs[]zr
}Keon.N?
dt0E0i
public FileAccessI(String sName,long nPos) throws IOException /2\=sTd
{ QGz3id6
oSavedFile = new RandomAccessFile(sName,"rw"); l0_E9qh-i
this.nPos = nPos; U;Y}2
oSavedFile.seek(nPos); ;YXrG
} -MW(={#
tG^?fc
8 8=c3^
public synchronized int write(byte[] b,int nStart,int nLen) N9h@1'>
{ Qbt>}?-
int n = -1; 6M vRR
try{ V45Udwp^
oSavedFile.write(b,nStart,nLen); (kNTXhAr4
n = nLen; % m5^p
} YM.IRj2/1
catch(IOException e) j nA_!;b
{ RqjDMN:
e.printStackTrace (); +:Q/<^Z
} [tK:y[nk
EC!Cv;'
n6UU6t{
return n; x7kg_`\U
} U <$xp
X%1.mTU~K
nC{rs+P
} l=?y=2+
o^"3C1j
ggsi`Z{j?
/* p6l@O3
**SiteInfoBean.java YM*6W?
*/ )MW}!U9G
package NetFox; o@`E.4
12'(MAP
/F}\V ^
public class SiteInfoBean { 7^TXlWn^G
NITx;iC
$yqq.#1
private String sSiteURL; //Site's URL j!o3g;j
private String sFilePath; //Saved File's Path GfPz^F=ie.
private String sFileName; //Saved File's Name x,G6`|Hl
private int nSplitter; //Count of Splited Downloading File u#,'ys
5Zm_^IS
.EZ{d
public SiteInfoBean() [ .uaO
{//nSplitter的缺省值为5 GE+csnA2
//default value of nSplitter is 5 ugPI1'f
this("","","",5); q>4i0p8^
} zd4y5/aoS
Z?aR9OTP
xt0j9{p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^&/&I9z
{ b!~%a
sSiteURL= sURL; Ngc+<
sFilePath = sPath; "{"2h>o#D}
sFileName = sName; _`[6jhNa!
this.nSplitter = nSpiltter; 5T3>fw2G
U`_vF~el~
Vzm+Ew _
} W@C tFU9
|5B9tjJ"
QF "&~
public String getSSiteURL() B^Mtj5Oc
{ ioCkPj
return sSiteURL; Ic!83-
} oxXW`C<
B{(l5B6
ZM, ^R?e
public void setSSiteURL(String value) G6VHl:e7z
{ ;iNx@tz4
sSiteURL = value; Qnx92
} Fe< t@W
pAmI ](
V46[whL%r
public String getSFilePath() lS-i9U/,>
{ \9zC?Cw
return sFilePath; 'X<uG x
} $KHDS:&
%,D%Q~
:"IH*7xp
public void setSFilePath(String value) oHnpwU
{ TFPq(i
sFilePath = value; ~0Q72
} P;pg+L.I
=JH,RQ *
GFkte
public String getSFileName() EQO7:vb
{ ]%hI-
return sFileName; P32'`!/:
} XhV"<&v
"T=LHjE
bkIA:2HX
public void setSFileName(String value) ~J:lCu
{ ?7a[|-
sFileName = value; L$Z_j()2
} H/{3 i
wuQkeWxJ
*.l=>#qF
public int getNSplitter() (@ sKE
{ z# B) b5
return nSplitter; =@l5He.]&
} 3$;v# P$%N
vdzC2T
{v(|_j&:o
public void setNSplitter(int nCount) ]!w52kF7
{ YO+d+5
nSplitter = nCount; QLl44*@
} <{kj}nxz
} TA7w:<
hp}8 3.oA
6dMpd4"\
/* A???s,F_
**Utility.java $hh=-#J8
*/ ljmHX2p
package NetFox; o\[nGf C&
:+$_(*Z
8~&v\GDkF
public class Utility { E;0"1 P|S
)\^OI:E
'"a8<7
public Utility() VF.S)='>Eu
{ S)?B I
}e)ltp|
Ycm1 _z
} &(0);I@fc
>EjBknl
//线程睡眠 nor`w,2VF
public static void sleep(int nSecond) &#.&xc2sRZ
{ T^W8_rm*3
try{ :+n7oOV
Thread.sleep(nSecond); :T2K\@
} FMiYZ1^r
catch(Exception e) 8~7EWl
{ Y&?]t
e.printStackTrace (); i7_BnJJX{B
} TkykI
} S5vJC-"
#'T@mA
//日志 h 9/68Gc?6
public static void log(String sMsg) 6O?O6Ub
{ @EvnV.
System.err.println(sMsg); =`")\?z}
} eZHi6v)i
@<+(40`*
-J:vYhq|g
public static void log(int sMsg) Qw ED>G|
{ (1R,
System.err.println(sMsg); @: NrC76
} {^v50d
} f|EWu
\AG,dMS
59LIK&w
/* y}|zH
**TestMethod.java 4V=dD<3m
*/ ,}<v:!
package NetFox; n*V^Qf
h^4oy^9
`8Gwf;P1
public class TestMethod { DF#Ob( 1
)pJzw-m"
[@(zGb8
public TestMethod() b`IC)xN$
{ ///xx/weblogic60b2_win.exe = hpX2/]
try{ +IU]=qS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); dW91nTQ:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x;N?'"GP
SiteFileFetch fileFetch = new SiteFileFetch(bean); SFuzH)+VO
fileFetch.start(); =,sMOJc>
} jjs-[g'}
catch(Exception e){e.printStackTrace ();} b"J(u|Du`
,30&VW##
7oUYRqd
} ^0VI J)y
-Q,lUP
_3`{wzMA
public static void main(String[] args) U7Ps2~x3
{ ]+oPwp;il
new TestMethod(); K@hv[4
} ]3%Z
} Hkpn/,D5
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