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)); K4r"Q*h
} B7*^rbI:X
for(int i=0;i<nEndPos.length-1;i++) h()Ok9]
{ [SJ)4e|)
nEndPos = nStartPos[i+1]; i;CVgdQ8
} fP:n=A{
nEndPos[nEndPos.length-1] = nFileLength; v$P<:M M
} RS8tE(
} mMz^I7$
9AA_e ~y
)1EF7.|
//启动子线程 $X>$)U'p&-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6t,_Xqg*
for(int i=0;i<nStartPos.length;i++) E#0_y4
{ >Q`\|m}x)Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )jS9p~FS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +1te8P*
nStartPos,nEndPos,i); Q^B !^_M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fcim4dfP
fileSplitterFetch.start(); >dr34=(
} r Ljb'\<*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0LjF$3GpZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g }%$VUSA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +K@wh
nEndPos = " + nFileLength); fMRv:kNAt
// fileSplitterFetch[nPos.length-1].start(); VV$$t;R/
nx2iEXsa
vFz#A/1
//等待子线程结束 /OX;3" +1
//int count = 0; vC# *w,
//是否结束while循环 PsV1btq]
boolean breakWhile = false; y{?wxg9
|5;:3K+
bXx2]E227
while(!bStop) 8iB}gHe9
{ N084k}io
write_nPos(); Xf"B\%,(`
Utility.sleep(500); 60iMfcT
breakWhile = true; ~ ~"qT
[?=Vqd
vmY 88Kx&S
for(int i=0;i<nStartPos.length;i++) J%:D%=9 )
{ UhI T!x
if(!fileSplitterFetch.bDownOver) ik;S!S\v
{ ,sOdc!![
breakWhile = false; ;b-d2R
break; mZ[tB/
} fH>I/%
} %mO.ur>21
if(breakWhile) :Sd"~\N+
break; q#6K'=AC
Os5Xejh`I
|})7\o
//count++; ~vL`[JiK
//if(count>4) 3SeM:OYq]s
// siteStop(); dw"Tv~
} I?z*.yA*
GY3g`M
KysJ3G.k\
System.err.println("文件下载结束！"); )J"*[[e
} >$g+Gx\v4
catch(Exception e){e.printStackTrace ();} =Qf.
} RyN}Gz/YN
FUD M]:XQ
Y\e8oIYu7
//获得文件长度 Q!T+Jc9N
public long getFileSize() G<MX94?
{ v5/2-<6x
int nFileLength = -1; "Q[rM1R
try{ u> @Yoyc
URL url = new URL(siteInfoBean.getSSiteURL()); KiaQ^[/q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9iwSE(},
httpConnection.setRequestProperty("User-Agent","NetFox"); z5UY0>+VdS
g?mfpwZj
s (hJ *
int responseCode=httpConnection.getResponseCode(); '1Z3MjX
if(responseCode>=400) #\{j/{VZ
{ G'dN_6ho3
processErrorCode(responseCode); c:@lR/oe"
return -2; //-2 represent access is error 8etNS~^
} !e0OGf
1pDL()t
v!~;QO
String sHeader; mjI $z3
S+LS!b
HXg#iP^tv
for(int i=1;;i++) VOa7qnh4:[
{ #K4lnC2qz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (9A`[TRwi
//Utility.log(in.readLine()); jW!x!8=
sHeader=httpConnection.getHeaderFieldKey(i); < 9 vS
if(sHeader!=null) u~-,kF@
{ c[6=&
if(sHeader.equals("Content-Length")) 50?5xSEM0_
{ Pi!3wy
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $Rd]eC
break; zg[.Pws:E
} XSv)=]{
} jW<aAd
else )d^b\On
break; "(QI7:iM
} 8euh]+
} 'y? HF@NJ
catch(IOException e){e.printStackTrace ();} Fb^Ae6/i
catch(Exception e){e.printStackTrace ();} X^%E"{!nU
$&@etsW0/
m`Dn R`+
Utility.log(nFileLength); vrr`^UB2
@8$3Q,fF(
(e~vrSk+)~
return nFileLength; o<f#Zi
} ~Bi{k'A9
MB#KLTwnT
A:JWUx
//保存下载信息（文件指针位置） % njcWVP;
private void write_nPos() "{X_[
{ d=$1Z.]
try{ 'y<<ce*
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3v:c".O2O
output.writeInt(nStartPos.length); J_tI]?jrU
for(int i=0;i<nStartPos.length;i++) l4LowV7
{ `(dRb
// output.writeLong(nPos); OZc.Rtgc
output.writeLong(fileSplitterFetch.nStartPos); [h=[@jiB
output.writeLong(fileSplitterFetch.nEndPos); Q*c |!< &e
} M .J
output.close(); .o_?n.H'&
} /`x)B(b
catch(IOException e){e.printStackTrace ();} sO;]l"{<
catch(Exception e){e.printStackTrace ();} }8\"oA6
} =JK# "'
8ba*:sb
(+=TKI<=
//读取保存的下载信息（文件指针位置） ;xl_9Ht/
private void read_nPos() noLb
{ !P"=57d}"l
try{ zm9_[0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ` g5S
int nCount = input.readInt(); mm@)uV<\
nStartPos = new long[nCount]; zr1,A#BV
nEndPos = new long[nCount]; uV'w0`$y
for(int i=0;i<nStartPos.length;i++) <Ky6|&!
{ J@4,@+X
nStartPos = input.readLong(); HbUadPr
nEndPos = input.readLong(); 50Kv4a"
} lDd8dT-Q.
input.close(); (!iGQj(m
} rQ!X
catch(IOException e){e.printStackTrace ();} aDreN*n
catch(Exception e){e.printStackTrace ();} UN"U#Si)
} ;[[GA0
$>M A
3~uWrZ.u
private void processErrorCode(int nErrorCode) GA.4'W^&a
{ i)[8dv
System.err.println("Error Code : " + nErrorCode); F#az&
} -?K?P=B;X
?{bAyh/
*wY { ~zh
//停止文件下载 nOE 1bf^l
public void siteStop() kpU-//lk+
{ ti}g?\VT
bStop = true; }K%y'D
for(int i=0;i<nStartPos.length;i++) hG3p"_L
fileSplitterFetch.splitterStop(); EgY yvS)
J BN_Upat
oD=6D9c?
} (XDK&]U
} IxxA8[^V
//负责部分文件的抓取 @N'0:0Nb_
**FileSplitterFetch.java {q}# Sq
*/ ji(Y?vhQt
package NetFox; ly)b=ph&
"~uo4n~H
G^ 2a<?Di
import java.io.*; wV,l }Xb-
import java.net.*; a!!>}e>Cj*
B2uLfi$q
'+Gy)@c
public class FileSplitterFetch extends Thread { U $ bLt
FKN!*}3
;%V%6:5
String sURL; //File URL yN Bb(!u
long nStartPos; //File Snippet Start Position -UhGacw
long nEndPos; //File Snippet End Position IRxFcLk
int nThreadID; //Thread's ID 1Z+\>~8
boolean bDownOver = false; //Downing is over =rrbS8To=
boolean bStop = false; //Stop identical fcC?1M[BP~
FileAccessI fileAccessI = null; //File Access interface >[U.P)7;
*k7vm%#ns
;J)8#|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7rdPA9
{ mAFVjSa2
this.sURL = sURL; Q.N, Q`P
this.nStartPos = nStart; YVEin1]
this.nEndPos = nEnd; f4k\hUA
nThreadID = id; Y8fahQ#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ZMVQo-=
} D}| 30s?u1
Zk4(
q[}[w!to
public void run() 2EdKxw3$]
{ t#p*{S 3u
while(nStartPos < nEndPos && !bStop) Dn#GoDMJ[
{ Fk 5;
U/|H%b
u7Xr!d+wR
try{ w<uK-]t
URL url = new URL(sURL); qC%[J:RwF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6,C,LT2^(
httpConnection.setRequestProperty("User-Agent","NetFox"); Nd"Rt
String sProperty = "bytes="+nStartPos+"-"; gmY*}d` 'f
httpConnection.setRequestProperty("RANGE",sProperty); U;_b4S:
Utility.log(sProperty); ,3zF_y(*Y
A/xWe
77Fpb?0`
InputStream input = httpConnection.getInputStream(); iSZiJ4AUq
//logResponseHead(httpConnection); l/JE}Eg(
"?lm`3W"
l u^fKQ
byte[] b = new byte[1024]; 9J$8=UuxWG
int nRead; J01Y%W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #e!4njdM
{ &d`z|Gx9
nStartPos += fileAccessI.write(b,0,nRead); wK7wu.
//if(nThreadID == 1) y,*>+xk,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _uR-Z_z
} ~[CtsCiQ
{\?zqIM
#()u=)
Utility.log("Thread " + nThreadID + " is over!"); g]z[!&%Ahs
bDownOver = true; %>cl0W3x
//nPos = fileAccessI.write (b,0,nRead); B~/LAD_
} _V9 O,"DDc
catch(Exception e){e.printStackTrace ();} tkG0xRH
} bs%lMa.o
} CXQPbt[5
4@wH4H8
F=29"1 ._
//打印回应的头信息 *hT1_
public void logResponseHead(HttpURLConnection con) 6PS #Zydb
{ Ua@rp3fr
for(int i=1;;i++) o@o6<OP^
{ myVV5#{
String header=con.getHeaderFieldKey(i); 9Q#eu~R
if(header!=null) 6!,Am^uXM
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JYbE(&l%de
Utility.log(header+" : "+con.getHeaderField(header)); 0RLyAC|
else Rv)!p~V8
break; 6T}bD[h4?
} "rjqDpH
} %r<c>sFJN
[Z5Lgg&
hm%'k~
public void splitterStop() 2>.2H
{ R|%R-J]
bStop = true; Y=oj0(Q*
} j;tT SNF
UH<nc;.B
Q}J'S5%
} H(^O{JC]y!
u#8J`%g
b"ypS7 _
/* Ufz& 2
**FileAccess.java LiyEF&_u
*//文件访问(定位，写) hSZ0 }/
package NetFox; :%dIX}F
import java.io.*; >b |TaQ
UC,43 z
IX7|_ci
public class FileAccessI implements Serializable{ -$(,&qyk
l_lm)'ag
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 sOJH$G3O
RandomAccessFile oSavedFile; zFjG20w%3g
long nPos; >-Qg4%m
o|7]8K=
rAdYBr=0
public FileAccessI() throws IOException B/i`
{ |S5N$[
this("",0); 9})!~r;|
} 41<.e`{
Phsdn`,
5q`d=L,
public FileAccessI(String sName,long nPos) throws IOException Ojkbv
{ Ge+&C RhyX
oSavedFile = new RandomAccessFile(sName,"rw"); ZDZPJp,
this.nPos = nPos; lD!o4ZAo
oSavedFile.seek(nPos); 7@MGs2
} ;SzOa7
n%w36_
&(fB+VNrOH
public synchronized int write(byte[] b,int nStart,int nLen) .,:700n+^
{ *v'&i) J
int n = -1; "hU'o&
try{ GNXQD}L?b?
oSavedFile.write(b,nStart,nLen); TxhTK5#f
n = nLen; ,w|f*L$
} uc?QS~H&w
catch(IOException e) V8>%$O sw
{ =nEl m*E
e.printStackTrace (); IKM=Q. 7j
} ]@op
C#X0Cn0ln
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return n; `zHtfox!
} eR(PY{
J!,5HJh1
]6{G;f$
} 29g("(}TK
(=${@=!z
Sd.i1w&
/* [8/E ;h
**SiteInfoBean.java >JFAE5tj&2
*/ ^f{+p*i}:
package NetFox; tvptawA.
XljiK8q;%
rUkiwqr~E
public class SiteInfoBean { Y%$57,Bu n
WlVC0&
wO!k|7:Z
private String sSiteURL; //Site's URL AigL:4[
private String sFilePath; //Saved File's Path $|!VP'VI
private String sFileName; //Saved File's Name {A4"KX(U
private int nSplitter; //Count of Splited Downloading File A%n l@`s,
#.0^;M5Nh
M'D;2qo
public SiteInfoBean() c"%XE#D
{//nSplitter的缺省值为5 2.Ym
//default value of nSplitter is 5 hq/k}Y
this("","","",5); 6hSj)
} F;jl0)fBR=
n{pS+u z
~130"WQ;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ([s}bD.9
{ F]3iL^v
sSiteURL= sURL; MJ>9[hs
sFilePath = sPath; xaWd\]UF
sFileName = sName; }U'fPYYi8
this.nSplitter = nSpiltter; yqqP7
m~\BkE/[l
e9hT
} Kz!-w
p^+k:E>U
i/*&;
public String getSSiteURL() \cvui^^n
{ @*L^Jgn
return sSiteURL; G*e/Ft.wf8
} `9eE139V='
\1f$]oS
.l5y!?
public void setSSiteURL(String value) %"j<`
{ lyKV^7}
sSiteURL = value; Mw7 ~:O`
} Ul OoMGg
+L*2 6ar6
<FmrYwt
public String getSFilePath() W,YzD&f=uS
{ V4f~#Tp
return sFilePath; }4Lv-9s,
} $k*E^~qT
!l@IG C
YY]JjMkU
public void setSFilePath(String value) i NzoDmE*
{ -G]\"ZGi
sFilePath = value; 2t\a/QE)E
} #"%oz^~\
R_.C,mR ?
^V v7u@y
public String getSFileName() Afo(! v
{ |h(!CFR
return sFileName; 7Q} P}9n
} #\iQ`Q<B
u&".kk
|vA3+kG
public void setSFileName(String value) T5,/;e
{ <r.f ?chf
sFileName = value; iSo+6gu
} e2;19bj&
dx}()i\@
"jmi "O*
public int getNSplitter() # SV*6
{ !NK8_p|X
return nSplitter; EUmQn8
} .Ff;St
XCoN!~
R>BI;IcX
public void setNSplitter(int nCount) -MJ6~4k2
{ 9mwL\j
nSplitter = nCount; j% !
} ;^lVIS%&{
} `4}zB#3
,*a8]L
qS>P,>C
/* OF,<K%A
**Utility.java 8 wQV^G
*/ [oKc<o7)~"
package NetFox; k uU,7<o
,d<wEB?\`
/!oi`8D
public class Utility { ${ad[hs
J %jfuj
AnG/A!G
public Utility() FVT_%"%C9
{ .VuZ=
fyYT#r
8b!&TP~m1
} DY^q_+[V
52/^>=t
//线程睡眠 'g^;_=^G
public static void sleep(int nSecond) M' "S:
{ a"EP`
try{ cgc|G
Thread.sleep(nSecond); i>_V?OT#5
} ]zmY]5
catch(Exception e) G#@o6r
{ v)!Rir5
e.printStackTrace (); 'h%)@q)J)
} &!2 4l=!
} M/:kh,3
fBS;~;l
//日志 E@hvO%
public static void log(String sMsg) <w+K$WE {
{ HGs.v}@&
System.err.println(sMsg); v0jRoE#
} 4&!`Yi_1L
}I}RqD:`
x,@cU}D
public static void log(int sMsg) Jj*XnL*
{ ,;y5Mu8
System.err.println(sMsg); hZVF72D26
} vi["G7
} :R{Xd{?
HZ5*PXg~
q El:2<
/* X2(TuR*t
**TestMethod.java tk|Ew!M:
*/ 0qnToV;
package NetFox; hvQOwA;e
2Y\,[$z
B<xBuW
public class TestMethod { -@Mr!!t?N
fBR,Oneo
I{JU<A,&
public TestMethod() 8GN0487H
{ ///xx/weblogic60b2_win.exe @ >%I\
try{ *^ \xH,.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ms=x~o'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /P<RYA~
SiteFileFetch fileFetch = new SiteFileFetch(bean); D\ HmY_
fileFetch.start(); R4 ;^R
} ]BP"$rs
catch(Exception e){e.printStackTrace ();} =&U JFu
NYM$0v`0YK
$fPf/yQmC
} vY7C!O/y_k
k=Pu4:RF
$^INl0Pg
public static void main(String[] args) zC(DigN
{ ]t\fw'
new TestMethod(); WO/;o0{d\9
} |#^u%#'[2
} "KcSOjvJ
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