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)); tr$~INe
} PgF7ug%,@C
for(int i=0;i<nEndPos.length-1;i++) 3~Vo]wv
{ 8I*WVa$l
nEndPos = nStartPos[i+1]; cWG?`6xU&
} 2V 9vS
nEndPos[nEndPos.length-1] = nFileLength; Qg;?C
} `VxfAV?}
} d)X6x-(
%knPeo&
d)7V:
//启动子线程 %T:7I[f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }v?_.MtS
for(int i=0;i<nStartPos.length;i++) G~;hD-D~.
{ 4)=\5wJDg1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /\&Wk;u3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G>fJ)A
nStartPos,nEndPos,i); muqIh!nn
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =7WE
fileSplitterFetch.start(); 09>lx$
} zxt&oT0Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7f9i5E1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZHku3)V=o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `]xot8
nEndPos = " + nFileLength); D3+UV+&R/
// fileSplitterFetch[nPos.length-1].start(); xRx8E;Q@h?
EL[N%M3
:jp4 !0w
//等待子线程结束 M;i4ss,}!
//int count = 0; /6%<97/d
//是否结束while循环 #FfUkV
boolean breakWhile = false; :6Q`! in
4vk^=
cPgz?,hE
while(!bStop) 0Tm"Zh?B|
{ ja2PmPv
write_nPos(); TdAHw @(
Utility.sleep(500); -UM5&R+o
breakWhile = true; @9!,]n
K{)YnY_E;
4l~0LdYXKm
for(int i=0;i<nStartPos.length;i++) xgeKz^,
{ zkt+"P{az[
if(!fileSplitterFetch.bDownOver) #' =rv
{ ;|e6Qc9
breakWhile = false; j`9+pI
break; MFyMo
} 'h6Vj6
} Gv};mkX[N
if(breakWhile) u,6 'yB'u
break; p2UZqq2
S}rW=hO
-Oro$=%
//count++; ?OU+)kgzh
//if(count>4) !%x=o&
// siteStop(); D*oJz3[
} \y%:[g}Fvw
/_rg*y*
jR^>xp;
System.err.println("文件下载结束！"); AF qut
} >qSaF
catch(Exception e){e.printStackTrace ();} 8\~IwtSk
} p?X`f#
G([!(8&2Y
:X`Bc"
//获得文件长度 =m4_8)-8u
public long getFileSize() 3??*G8Yp
{ om"q[Tudc
int nFileLength = -1; *Iu .>nw
try{ ZhWtY
URL url = new URL(siteInfoBean.getSSiteURL()); $z9z'^HqO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b (,X3x*
httpConnection.setRequestProperty("User-Agent","NetFox"); K_Jo^BZ
C(-bh]J
Hset(-=X
int responseCode=httpConnection.getResponseCode(); H:ar&o#(
if(responseCode>=400) 7b_Ihv
{ qR~s&SC#
processErrorCode(responseCode); BW>f@;egg
return -2; //-2 represent access is error 4^L+LY
} uxq!kF'Ls
$h Isab_
[1Dg_>lz
String sHeader; $?OuY*ZeY9
h<wF;g,
XB &-k<C
for(int i=1;;i++) _BcYS
{ ?D#]g[6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SR#%gR_SC
//Utility.log(in.readLine()); Xf.w(-
sHeader=httpConnection.getHeaderFieldKey(i); S?}@2[
if(sHeader!=null) RN?z)9!
{ ;mXr])J
if(sHeader.equals("Content-Length")) /:a~;i
{ `j59MSuK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VY'#>k}}
break; g5)f8k0+ t
} Aa5IccR
} Kt%`]Wp
else Fc;)p88[
break; `A\ !Gn?
} y?-wjJS>
} "R$ee^
catch(IOException e){e.printStackTrace ();} JF>mybB
catch(Exception e){e.printStackTrace ();} /tno`su;
4QnJ;&~
K5Fzmo a
Utility.log(nFileLength); '|e5cW6z
m7 !Fb
Q:]F* p2
return nFileLength; 46'EZ@#s
} 7 :s6W%W1*
.E_`*[ 5=
K \}xb2s
//保存下载信息（文件指针位置） yZaQ{]"
private void write_nPos() '3wte9E/
{ v=:RxjEx
try{ Gb%PBg}HH
output = new DataOutputStream(new FileOutputStream(tmpFile)); #Dx$KPD
output.writeInt(nStartPos.length); EIl _QV6
for(int i=0;i<nStartPos.length;i++) a%f5dj+
{ T7YzO,b/
// output.writeLong(nPos); :yvUHx
output.writeLong(fileSplitterFetch.nStartPos); S<Q6b_D
output.writeLong(fileSplitterFetch.nEndPos); >P5 EW!d
} wX7B&w8wV
output.close(); nTjQ4y
} FuaGr0]
catch(IOException e){e.printStackTrace ();} ]?U:8%
catch(Exception e){e.printStackTrace ();} -5A@FGh
} muQ7sJ9 r
^HHJ.QR
uJG^>B?`b
//读取保存的下载信息（文件指针位置） LX j Tqp'
private void read_nPos() &hs)}uM&$
{ .N]^g#
try{ pTmG\wA~$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7,|-%!p[
int nCount = input.readInt(); +v&+8S`+
nStartPos = new long[nCount]; Hux#v>e
nEndPos = new long[nCount]; 8T 6jM+ h
for(int i=0;i<nStartPos.length;i++) bt#=p7W
{ >k^=+
nStartPos = input.readLong(); 3Nw9o6`U
nEndPos = input.readLong(); E/_=0t
} -4b9(
input.close(); 2:i`,
} *D]/V U
catch(IOException e){e.printStackTrace ();} Zx5vIm
catch(Exception e){e.printStackTrace ();} hGF:D#jyT
} k+-u4W
6R@ v>}
CQsVGn{x
private void processErrorCode(int nErrorCode) 2`t4@T
{ a+*|P
System.err.println("Error Code : " + nErrorCode); 4MRHz{`wa
} x!!:jL'L
H5/%"1Q
l4u`R(!n5
//停止文件下载 -BACdX
public void siteStop() pz?.(AmU\
{ Q=~e|
bStop = true; Oa7`Y`6
for(int i=0;i<nStartPos.length;i++) oHu0] XA
fileSplitterFetch.splitterStop(); 2NsI3M4$8
Qd]-i3^0
ep[7#\}5
} y{K~g<VL
} ?{cF'RB.
//负责部分文件的抓取 " I`<s<
**FileSplitterFetch.java `-Gs*#(/
*/ &e_M \D
package NetFox; G?=X!up(
hig^ovF
+t/VF(!
import java.io.*; ~mK9S^[
import java.net.*; `EU=u_N
WABq6q!
Z\i@Qa+r
public class FileSplitterFetch extends Thread { 0?SdAF[:z
L !yl^c
SLz^Wg._
String sURL; //File URL *8js{G0h
long nStartPos; //File Snippet Start Position 62%.ddM4
long nEndPos; //File Snippet End Position 6E@r9U
int nThreadID; //Thread's ID |/ZpZ7
boolean bDownOver = false; //Downing is over l[Ng8[R
boolean bStop = false; //Stop identical ;{BELv-4
FileAccessI fileAccessI = null; //File Access interface 2={`g/WeE
rq}ew0&/
_l}&|:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^N`ar9Db
{ wp.<}=|u
this.sURL = sURL; $>5|TG 0i
this.nStartPos = nStart; %S.R@C[3
this.nEndPos = nEnd; /$WEO[o
nThreadID = id; XkuNLs4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y'bDEdeT
} "=9L7.E)
?KI_>{
6/s#'#jh
public void run() F7#
{ %dO'kU/-
while(nStartPos < nEndPos && !bStop) qN}0$x>p
{ rt!5Tl+v
#\@*C=
E;D9S
try{ e][U ;
URL url = new URL(sURL); IR(JBB|xNQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GJ ZT~
httpConnection.setRequestProperty("User-Agent","NetFox"); QF'N8Kla
String sProperty = "bytes="+nStartPos+"-"; ?$pp%
httpConnection.setRequestProperty("RANGE",sProperty); U $X"W'
Utility.log(sProperty); id&;
?J6J#{LRd
Z!~~6Sq
InputStream input = httpConnection.getInputStream(); sh:sPzQ%Jv
//logResponseHead(httpConnection); ga6M8eOI
>=6tfLQ
l>7`D3
byte[] b = new byte[1024]; e<9IwS!/
int nRead; JQi)6A?J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RBwI*~%g{
{ O|?>rK
nStartPos += fileAccessI.write(b,0,nRead); jUI'F4.5x-
//if(nThreadID == 1) wb.47S8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aJOhji<b#L
} MY4cMMjp~
[[Qu|?KEa
=d.Z:L9d
Utility.log("Thread " + nThreadID + " is over!"); { >bw:^F
bDownOver = true; FJp~8 x=
//nPos = fileAccessI.write (b,0,nRead); >q[(UV
} 3iR;(l}
catch(Exception e){e.printStackTrace ();} \;.\g6zX
} +P6q wh\v
} t]2~aK<]
4}!riWR
~*- eL.
//打印回应的头信息 E Rqr0>x
public void logResponseHead(HttpURLConnection con) |.)oV;9
{ vtv|H
for(int i=1;;i++) 5yuj}/PZ
{ +0;6.PK
String header=con.getHeaderFieldKey(i); U<KvKg
if(header!=null) AWi~qzTZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |t!kD(~r
Utility.log(header+" : "+con.getHeaderField(header)); Vqb4 MWW
else b Zn:q[7
break; 8uchp
} (@pE
} #K"jtAm
!WR(H&uBr\
# ~} 26
public void splitterStop() bezT\F/\
{ uv/I`[@HK8
bStop = true; k*w]a
} Ky8sLm@
imZi7o
C~yfuPr\B
} 1*Yf[;L
V&eti2&zO
bT|a]b:
/* /![S 3Ol
**FileAccess.java *rXESw]BR
*//文件访问(定位，写) ?76Wg::
package NetFox; 0gL]^_+7
import java.io.*; x$[<<@F%
z+@aQ@75
*}-X '_
public class FileAccessI implements Serializable{ I_6?Q^_uZ
<_dyUiT$J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 UwvGw5)q
RandomAccessFile oSavedFile; \|F4@
long nPos; D}>pl8ke~g
~>VEg3#F
\j+O |#`|)
public FileAccessI() throws IOException [V|,O'X ~
{ E!8FZv8
this("",0); _[<R<&jG
} >8"oO[U5>
r1\c{5Wt
'nz;|6uC
public FileAccessI(String sName,long nPos) throws IOException j\B]>PP5
{ osoreo;V^
oSavedFile = new RandomAccessFile(sName,"rw"); d(3F:dbk
this.nPos = nPos; X*KQWs.
oSavedFile.seek(nPos); X|TEeE c[L
} .0:BgM
3{LXx
O#7ONQfBO
public synchronized int write(byte[] b,int nStart,int nLen) Hzcy'
{ 2E33m*C2
int n = -1; ug'I:#@2
try{ GbFLu`Iu
oSavedFile.write(b,nStart,nLen); y<W?hE[
n = nLen; 2?u>A3^R
} n (7m
catch(IOException e) 0&mo1 k_U
{ @zL)R b%P$
e.printStackTrace (); r Lg(J|^
} vIF=kKl9,
Sf);j0G,D
)@09Y_9r
return n; X^r5su?
} \V /s
SpPG
an_qE}P
} Jkzt=6WZ0
X6kB R
rbiNp6AdL
/* [R+zzl&Zw
**SiteInfoBean.java r(y1^S9!8
*/ !rZO~a0
package NetFox; |R8=yO%(
(~:k70V5
T]Gxf"mK
public class SiteInfoBean { C)~YWx@v
XKp.]c wP
"u~l+aW0
private String sSiteURL; //Site's URL Tf7$PSupP
private String sFilePath; //Saved File's Path gcqcY
private String sFileName; //Saved File's Name a*REx_gLG
private int nSplitter; //Count of Splited Downloading File ]W7(}~m
J~eY,n.6]
M[}EVt~
public SiteInfoBean() q>/# P5V
{//nSplitter的缺省值为5 8Y*SZTzV
//default value of nSplitter is 5 Fh9%5-t:J
this("","","",5); l>`N+ pZ$
} R $HIJM
j/4N
_IuEa\>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) },KY9w
{ /e1m1B
sSiteURL= sURL; gP"p7\ (
sFilePath = sPath; )X@Obg
sFileName = sName; %^n9Z/I
this.nSplitter = nSpiltter; *vc=>AEc
!8yw!hA
AFcsbw
} CP_ ?DyWU
L&=j O0_
A`v(hBM
public String getSSiteURL() %VOn;_Q*B
{ F]]np&UV.
return sSiteURL; ,B%M P<Rz1
} xB_F?d40T5
#/$}zl
["- pylhK
public void setSSiteURL(String value) AWHB^}!}
{ e:hkWcV
sSiteURL = value; <MZ$baK
} &dF$:$'s
Rn~FCj,-
5W"nn
public String getSFilePath() mA}-hR%
{ OLJb8kO
return sFilePath; $C0NvJf
} sUN>uroi !
"'h?O*V]u{
$gT+Ue|7
public void setSFilePath(String value) jXvGL
{ 3p{N7/z(
sFilePath = value; UZ0fw@RM
} ;"SnCBt:>
2|@@xF
fI>>w)5
public String getSFileName() ?#!Hm`\.
{ /AV [g^x2
return sFileName; qp 4.XL
} n"vl%!B
C=(-oI n
F+,X%$A#?
public void setSFileName(String value) JW9^C
{ ,X(P/x{B
sFileName = value; ((^jyQ
} !|_b}/
SQ|pH"
9+"D8J7
public int getNSplitter() QW#]i
{ r`XIn#o
return nSplitter; |7]7~ 6l
} Ou</{l/
'Bb]<L`
Epj
public void setNSplitter(int nCount) J01w\#62pQ
{ 7)$U>|=
nSplitter = nCount; J~KWn.
} x3=W{Fv@4
} ^6[KzE#*
}uo5rB5D
s (|T@g
/* B3K!>lz
**Utility.java S>}jsP:V
*/ 26JP<&%L
package NetFox; 3xef>Xv=
*k==2figz
\kcJF'JFA0
public class Utility { z_R^n#A~r
JL $6Fw;
\o !
public Utility() _6"vPN
{ Pc>$[kT0
WRU/^g3O@'
O%5cMz?eU
} sv\'XarM
:zfnp,Gv
//线程睡眠 v#&r3ZW0
public static void sleep(int nSecond) _ _cJ+%e
{ ~E-YXl9
try{ ?g|K"P<1
Thread.sleep(nSecond); v{`Z
} K y~ 9's
catch(Exception e) UgDai?b1
{ -q' np0H
e.printStackTrace (); jUtrFl
} (1H_V(
} 9\i;zpN\
q"ba~@<BEl
//日志 TEz)d=
public static void log(String sMsg) 1rh\X[@
{ Onb*nm
System.err.println(sMsg); hh<5?1
} wGa0w*$
FP<RoA?W
qd{o64;|
public static void log(int sMsg) GjZ@fnF
{ {:m5<6?x)
System.err.println(sMsg); PbxuD*LQ.
} MK9?81xd
} 84L!r
r5Ej
zk5sAHQ
/* Hb'fEo r
**TestMethod.java H^xrFXg~z
*/ !jY/}M~F1
package NetFox; X@Eq5s
SdC505m0*
%(;jx
public class TestMethod { *E:w377<}
fI`T3Y!7
GJWC}$#TY
public TestMethod() %8/Gsu;
{ ///xx/weblogic60b2_win.exe 5Zs"CDU
try{ \<|a>{`7]i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g3n^ <[E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nQK@Uy5Yr
SiteFileFetch fileFetch = new SiteFileFetch(bean); &=fBqod
fileFetch.start(); /eDah3%d
} R<LW*8
catch(Exception e){e.printStackTrace ();} S1uW`zQ!+_
]n?a h
O/_}O_rR
} 9pE)S^P
~]Mq'
W6'+#Fp
public static void main(String[] args) Z]$yuM
{ 1w+OnJI?
new TestMethod(); pTUsdao^,
} 1mOZ\L!m*
} ']$ttfJB
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