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)); S,m(
} K*/oWYM]
for(int i=0;i<nEndPos.length-1;i++) +A| Bc~2!
{ Q|'f3\
nEndPos = nStartPos[i+1]; J:Cr.K`
} 4t, 2H"M
nEndPos[nEndPos.length-1] = nFileLength; aLa<zEssz
} D:z'`v0j
} uvId],dQ5
A)f-r
, >LJpv
//启动子线程 +fP.Ewi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -?Cr&!*B
for(int i=0;i<nStartPos.length;i++) G:AA>t
{ 5\Q Tm;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p*;!5;OUR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'nCVjO7o
nStartPos,nEndPos,i); AV5={KK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i,6OMB $
fileSplitterFetch.start(); Ykxk`SJ
} 7%*#M#(T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &jE\D^>ko
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6"&cQ>$xh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d?zSwLsl
nEndPos = " + nFileLength); 1}(22Q;
// fileSplitterFetch[nPos.length-1].start(); TeHJj`rdAU
yf&g\ke
O^L]2BVC
//等待子线程结束 i2=- su
//int count = 0; W/Dd7G#IC
//是否结束while循环 L@N%S Sf
boolean breakWhile = false; D=e*rrL7a
4V@%Y,:ee
Q:A#4Z
while(!bStop) nLN0zfhE#
{ HpnF,4A>
write_nPos(); )w7vE\n3
Utility.sleep(500); 3~>-A=
breakWhile = true; @j!,8JQEd
eh86-tQI~(
CMj =4e
for(int i=0;i<nStartPos.length;i++) ,'8%'xit
{ roADC?@r
if(!fileSplitterFetch.bDownOver) %U\,IO`g
{ lw@Yn>eza
breakWhile = false; 3&hR#;,"X
break; zp}7p~#k^
} ;_<~9;
} Q((&Q?Vi
if(breakWhile) sxNf"C=-.
break; [D"6&
z|#*c5Y9w
?P kJG,~
//count++; wC1pfXa
//if(count>4) _*mn4n=
// siteStop(); P5Xp #pa
} AyE*1 FD
.S k+"iH5
%2QGbnt_*
System.err.println("文件下载结束！"); I9X\@lTf
} )z[C=
catch(Exception e){e.printStackTrace ();} ,^/Wv!uPE
} ]LvP)0=
S\GWMB!oF
8E%LhA.
//获得文件长度 #(^<qr
public long getFileSize() |AYii-g
{ 4 &bmt
int nFileLength = -1; 7:4c\C0
try{ m$vq%[/#
URL url = new URL(siteInfoBean.getSSiteURL()); x-%O1frc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MBWoPK
httpConnection.setRequestProperty("User-Agent","NetFox"); b}! cEJY
"wcaJ;Os
+~8Lc'0aA
int responseCode=httpConnection.getResponseCode(); 8zK#./0\
if(responseCode>=400) 'uu*DgEr
{ ]IuZT
processErrorCode(responseCode); "~4V(
return -2; //-2 represent access is error 5rsz2;#p
} ufXWK3~\
"Bd-h|J
9g6$"',H
String sHeader; N:`_Vl
L=lSW7R
9z(SOzZn
for(int i=1;;i++) }B0[S_mw
{ <"3q5ic/Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [jgVN w""D
//Utility.log(in.readLine()); hK?GIbRZ
sHeader=httpConnection.getHeaderFieldKey(i); "r^RfZ;
if(sHeader!=null) |8` }8vo)
{ ex>7f%\
if(sHeader.equals("Content-Length")) @76}d
{ E@ea?Sx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #2]*qgA4
break; SeHrj&5U
} S{^x]h|?
} 72l:[5ccR
else }a"=K%b<\
break; A$2 ;Bf
} aO{@.
} j@xIa-{*
catch(IOException e){e.printStackTrace ();} bxa>:71
catch(Exception e){e.printStackTrace ();} r_+Vb*|Y
=%U&$d|@G
)Jt. Z^J<
Utility.log(nFileLength); mm>l:M TF
GCl *x:
WJ8i=MO67
return nFileLength; $%EX~$=m]-
} h0F=5| B
@Ou H=<YN
Cu@q*:'
//保存下载信息（文件指针位置） & AK\Pw)
private void write_nPos() ]!ai?z%cK#
{ %{ BV+&
try{ h1~h&F?
output = new DataOutputStream(new FileOutputStream(tmpFile)); %bw+>:Tr
output.writeInt(nStartPos.length); g4+K"Q/M
for(int i=0;i<nStartPos.length;i++) 6FDj:~
{ "](Q2
// output.writeLong(nPos); )>~jjR
output.writeLong(fileSplitterFetch.nStartPos); 3EYEd39E
output.writeLong(fileSplitterFetch.nEndPos); z</C)ObL
} f0P,j~]
output.close(); JSUD$|RiJ
} 2TGND-(j
catch(IOException e){e.printStackTrace ();} -;cF)C--12
catch(Exception e){e.printStackTrace ();} S(.J
} vjX,7NY?
P5my]4|x
#M!u';bZ
//读取保存的下载信息（文件指针位置） %oiF} >
private void read_nPos() gdIk%m4
{ /Xi21W/
try{ 3P!OP{`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _i>_Sn1"
int nCount = input.readInt(); `,4yGgD!4
nStartPos = new long[nCount]; )M;~j
nEndPos = new long[nCount]; 0er|QC
for(int i=0;i<nStartPos.length;i++) SY Bp-o
{ t,YRM$P
nStartPos = input.readLong(); K~#?Y,}O
nEndPos = input.readLong(); e6p3!)@P1
} M4Cb(QAVP
input.close(); I'xc$f_+
} (?Ko:0+*
catch(IOException e){e.printStackTrace ();} Ucv7`W gr
catch(Exception e){e.printStackTrace ();} hTa X@=Ra
} P4B|l:
i6yA>#^
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private void processErrorCode(int nErrorCode) '/`O*KD]
{ @vq)Y2)r\
System.err.println("Error Code : " + nErrorCode); cn}15JHdR
} Q m*z
3>n&u,Xe
B-g-T>8
//停止文件下载 4- QlIIf
public void siteStop() }`CF(Do
{ )ThNy:4
bStop = true; C9+rrc@4
for(int i=0;i<nStartPos.length;i++) <Y6Vfee,&
fileSplitterFetch.splitterStop(); by1q"\-,
NK|U:p2H
cq>J]35
} y)KIz
} ~AD>@;8fG
//负责部分文件的抓取 YnnK]N;\x
**FileSplitterFetch.java ;40Z/#FI
*/ }Rz,}^B
package NetFox; G9XkimQ'
!{*yWpZ:
8^EWD3N`
import java.io.*; cEf"m?w
import java.net.*; ;G`]`=s#Lq
<k[_AlCmsg
u$tst_y-
public class FileSplitterFetch extends Thread { gZ&4b'XS,
4U\>TFO
W'"hjQ_
String sURL; //File URL a5Vlfx
long nStartPos; //File Snippet Start Position }c||$
long nEndPos; //File Snippet End Position N5)H(<}
int nThreadID; //Thread's ID AAfhh5i
boolean bDownOver = false; //Downing is over gK~Z Ch
boolean bStop = false; //Stop identical MMk9rBf
FileAccessI fileAccessI = null; //File Access interface 2Bi]t%<{
i-w<5pGnf
lZ5-lf4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^XeJZkLEB
{ ^5MM<73
this.sURL = sURL; ^jL44?W}l
this.nStartPos = nStart; ,Gy,bcv{
this.nEndPos = nEnd; ts&\JbL
nThreadID = id; ?1g`'q@T%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 o#"yFP1
} _*=4xmB.=
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#&uajo
public void run() ?#c "wA&
{ :$VGqvO12W
while(nStartPos < nEndPos && !bStop) 1/\Xngd
{ `hY%HzV=
Qxy~%;X
DEu0Z
try{ !0^4D=dO
URL url = new URL(sURL); el<Gd.p.d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1\Bh-tzB
httpConnection.setRequestProperty("User-Agent","NetFox"); auIW>0?}
String sProperty = "bytes="+nStartPos+"-"; 5Bq;Vb
httpConnection.setRequestProperty("RANGE",sProperty); d$o m\@
Utility.log(sProperty); _!|$i
t{UWb~"
2@T0QJ
InputStream input = httpConnection.getInputStream(); n[y=DdiKGS
//logResponseHead(httpConnection); ?lqqu#;8
Q,9KLi3
T-n>+G{
byte[] b = new byte[1024]; ~{g/
int nRead; %;]/Z%!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z1tD2jL_
{ pqvl,G5
nStartPos += fileAccessI.write(b,0,nRead); (=rDt93J
//if(nThreadID == 1) i:N-Q)<Q*)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \8*j"@ !H
} us5Zi#}
kLs{B
%iPIgma
Utility.log("Thread " + nThreadID + " is over!"); 5Th\wTh04
bDownOver = true; aiX4;'$x!
//nPos = fileAccessI.write (b,0,nRead); f dJg7r*
} 08@4u L
catch(Exception e){e.printStackTrace ();} -A}$5/
} Yrf?|,
} 4]zn,g?&
P5dD&
h`Ej>O7m
//打印回应的头信息 6qV1_M#
public void logResponseHead(HttpURLConnection con) ~K)FuL[*
{ s%#u)nw19
for(int i=1;;i++) ;=%cA#}_0
{ ]ml'd
String header=con.getHeaderFieldKey(i); #6y fIvap
if(header!=null) {?w*n_T.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9JMf T]
Utility.log(header+" : "+con.getHeaderField(header)); *XDe:A
else 9]chv>dO)=
break; W7s
} @w%kOX
} \Rt>U|%
f[`&3+
~6u|@pnI
public void splitterStop() cWQ &zc
{ ;eFV}DWW
bStop = true; taVK&ohWx
} U/HF6=Wot
MD;,O3Ge
&H,UWtU+
} m-[xrVV
6P9#6mZ
[$>@f{:
/* ,DWq
**FileAccess.java Rc@lGq9
*//文件访问(定位，写) Z@JTZMN_
package NetFox; %"E!E1_Sv
import java.io.*; KKg\n^
:[PA.Upi
u3 +]3!BQ
public class FileAccessI implements Serializable{ K^/.v<w
>Ir?)h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (t"|XSF
RandomAccessFile oSavedFile; Vw.4;Zy(
long nPos; FAGi`X<L
n68qxD-X
O#^qd0e'P!
public FileAccessI() throws IOException sV%=z}n=
{ frQ=BV5%6
this("",0); EN>a^B+!
} 4dz Ym+vJm
(:+Wc^0
!}eq~3
public FileAccessI(String sName,long nPos) throws IOException M.$=tuUL
{ 925T#%y
oSavedFile = new RandomAccessFile(sName,"rw"); 5}]gL
this.nPos = nPos; `]&'yt
oSavedFile.seek(nPos); DM,;W`|6%
} ~2NTXp
8M['-
tuo'Uk)
public synchronized int write(byte[] b,int nStart,int nLen) :K \IS`
{ \u/=?b
int n = -1; #)T'a
try{ I$TD[W
oSavedFile.write(b,nStart,nLen); s,laJf
n = nLen; Q."rE"}<
} FGo)]U
catch(IOException e) >^f]Lgp
{ wC<FF2T
e.printStackTrace (); 85H*Xm?d#
} !$-QWKD4
poZ&S
pL.~z
return n; v`jFWq8I,
} WK SWOSJ
3\B~`=*q/
LKud'
} !?B2OE
@nj`T{*.
&4p~i Z
/* Ys5Iqj=mp
**SiteInfoBean.java gFM~M(
*/ >ZAn2s
package NetFox; {mHxlG)
T!pHT'J
9\r5&#<(I
public class SiteInfoBean { *; 6LX
-,"eN}P^
fb!>@@9Z
private String sSiteURL; //Site's URL 8L))@SA+uJ
private String sFilePath; //Saved File's Path *u34~v16,
private String sFileName; //Saved File's Name y$|OE%S
private int nSplitter; //Count of Splited Downloading File mndNkK5o
H//,qxDc
4d-"kx3X
public SiteInfoBean() 6A} 45
{//nSplitter的缺省值为5 y|#Fu
//default value of nSplitter is 5 \FIOFbwe
this("","","",5); |P"kJ45
} AIwp2Fz
VB+y9$Y'
( 2KopL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I\6^]pi,
{ B{Lzgw u;
sSiteURL= sURL; L<N=,~
sFilePath = sPath; $I3}%'`+
sFileName = sName; }Do$oyAV$G
this.nSplitter = nSpiltter; V#-8[G6Ra
4L2TsuLw
lHgmljn5u
} ]u >~:
Znh<r[p<
4V5h1/JPm
public String getSSiteURL() A@G%*\UZ
{ 0~nub
return sSiteURL; >uz3 O?z P
} Qb1hk*$=
v}"DW?
$,7Yo nc
public void setSSiteURL(String value) k`,>52
{ Mg{=(No
sSiteURL = value; nA#dXckoc
} qmGLc~M0
D +9l$**a
-IG@v0_w
public String getSFilePath() $)M5@KT
{ ]AB4w+6!
return sFilePath; IaR D"oCH
} ,A!0:+
)ocr.wU@
H}}C>p"!,
public void setSFilePath(String value) b(:U]>J
{ |`ZW(}~
sFilePath = value; !&vPG>V
} um1xSf1Xv
;Z{jol
b*"%E,?
public String getSFileName() |jTRIMj%,_
{ 7,Q>>%/0P
return sFileName; 5'[b:YC
} E(Y}*.\]#s
J0x)NnWJ
18gApRa
public void setSFileName(String value) 6{TUs>~
{ o0F&,|'
sFileName = value; }:hN}*H
} ps3jw*QZ{5
E4N{;'
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public int getNSplitter() {:c5/ ,7c;
{ Q}:#Hz?U
return nSplitter; @j=Q$k.GF
} vAjvW&'g
<K zEn+
^s?=$&8f![
public void setNSplitter(int nCount) *VgiJ
{ MI\35~JAN
nSplitter = nCount; Q6rvTV'vv
} gX!-s*{E
} swLrp 74
<#F@OU
eNX!EN(^
/* 0 pPSg9
**Utility.java g!DJW
*/ @PAT|6
package NetFox; oA]rwaUX
6#(==}Sm+
i-gN<8\v
public class Utility { ]YWz;Z
?n(OH~@$i
g}n-H4LI
public Utility() aGq1YOD[$
{ 9vI<\ Xa
="J *v>
^c|_%/
} T1#r>3c\
XDohfa_
//线程睡眠 iR]K!j2
public static void sleep(int nSecond) ~EtwX YkRZ
{ W!t=9i
try{ Cd2A&RB
Thread.sleep(nSecond); h yK&)y?~
} cB=ExD.Q
catch(Exception e) T7~H|%
{ H5>?{(m
e.printStackTrace (); h0a|R4J
} y~n1S~5cI
} {2F@OfuCF
SNtk1pG>
//日志 h?'~/@
public static void log(String sMsg) @L$!hTaP
{ Q|xa:`3?
System.err.println(sMsg); 76cLf~|d~
} .F},Z[a&
hjD%=Ri0Z
Q$(Fma4a
public static void log(int sMsg) +\]Gu(z<
{ ,pIh.sk7s*
System.err.println(sMsg); D$N;Qb
} LhRd0
} 2Gh&h(
$C{,`{=
Z@(KZ|
/* 5]xSK'6W
**TestMethod.java CEW1T_1U<\
*/ _&%FGcAS
package NetFox; !<24Cy
aW-6$=W
TV=K3F5)M
public class TestMethod { #a9O3C/MP
LcZ|A;it
J$5Vjh'aM
public TestMethod() NfUt\ p*
{ ///xx/weblogic60b2_win.exe ||?@pn\
try{ $<yhEvv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +Qf}&D_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tzthc*-<
SiteFileFetch fileFetch = new SiteFileFetch(bean); inip/&P?V
fileFetch.start(); R0%M9;>1
} PD&gC88
catch(Exception e){e.printStackTrace ();} c]zFZJ6M
f7y.##WG
`BVmuUMm
} ]IEZ?+F,
GC:q6}
kg 8Dn
public static void main(String[] args) ,yA[XAz~U
{ ^Kg n:l
new TestMethod(); 4Y$\QZO
} S'5Zy} +x
} lLDZ#'&An
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