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)); 8r*E-akuyr
} W>${zVu
for(int i=0;i<nEndPos.length-1;i++) %^?fMeI|Y
{ ui<N[
nEndPos = nStartPos[i+1]; |UkR'Ma
} Gt\lFQ
nEndPos[nEndPos.length-1] = nFileLength; a!zz6/q[
} .<->C?#
} tIWmp30S
xs{3pkTYD
]N~2 .h
//启动子线程 )1]ZtU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2i)^!c
for(int i=0;i<nStartPos.length;i++) bg!/%[ {M
{ W,K;6TZhh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ansk,$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1$xNUsD2
nStartPos,nEndPos,i); h1j!IG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ty8q11[8
fileSplitterFetch.start(); "Bh}}!13
} T-'OwCB1q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )MtF23k)g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w^\52
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T`9lV2x*P
nEndPos = " + nFileLength); .iYJr;9`d
// fileSplitterFetch[nPos.length-1].start(); @KXV%a'
:N:yLd} &
S(k3 `;K
//等待子线程结束 OC_+("N
//int count = 0; ~k"=4j9
//是否结束while循环 piJu+tUy
boolean breakWhile = false; ~Q Oe##
h){0rX@:&
@D]5civm_
while(!bStop) [u =+3b
{ X1DF*wI
write_nPos(); DHyq^pJ
Utility.sleep(500); qSM|hHDo)
breakWhile = true; S.mG?zbw
{AhthR%(1
-z ID x
for(int i=0;i<nStartPos.length;i++) A`N,
{ TEP,Dq
if(!fileSplitterFetch.bDownOver) ;dkYf24
{ T]^62(So
breakWhile = false; )%`c_FL@N=
break; &DS/v)]
} xzdf^Ce
} GF"hx`zyJ
if(breakWhile) ]{sU&GqBLe
break; _:ReN_0
-Fi`Z$
KWq+PeB5TS
//count++; B?OFe'*
//if(count>4) o8 IL$:
// siteStop(); $By<$
} 8^kGS-+^
/}((l%UE.
IY_iB*T3jt
System.err.println("文件下载结束！"); ]P9l jwR
} y;4OY
catch(Exception e){e.printStackTrace ();} 4(#'_jS
} 1NbG>E#Ol
MS nG3]{z
%2}-2}[>
//获得文件长度 v3*_9e
public long getFileSize() D.r<QO~6B
{ 2+RUTOv/d
int nFileLength = -1; yjO1 Ol
try{ .Hescg/S
URL url = new URL(siteInfoBean.getSSiteURL()); \Q {m9fE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _jvxc'6
httpConnection.setRequestProperty("User-Agent","NetFox"); A9[ F
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int responseCode=httpConnection.getResponseCode(); n"h`5p5'
if(responseCode>=400) ]>W6 bTK
{ UBv,=v
processErrorCode(responseCode); df*#!D7oz
return -2; //-2 represent access is error EZgq ?l~5O
} 59 h]UX=
Ka'=o?'B5
nB_?ckj,
String sHeader; C>]0YO k2
xI{)6t$`
g!|=%(G=
for(int i=1;;i++) [NF'oRRD9s
{ ^dI424
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5A,K6f@:g
//Utility.log(in.readLine()); ,j#XOy`mzy
sHeader=httpConnection.getHeaderFieldKey(i); R]JT&p|w.1
if(sHeader!=null) ,A9]CQ
{ hE &xE;
if(sHeader.equals("Content-Length")) >d(~#Z`
{ EW}Bzh>b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $1SPy|y
break; zU,9T
} 3Lfqdqj
} 0^v`T%|fTX
else KsddA
break; V~UN
} "0$a)4]
} >;jZa
catch(IOException e){e.printStackTrace ();} 3(``#7
catch(Exception e){e.printStackTrace ();} ?'IP4z;y
M5i%jZk
[ieI;OG;
Utility.log(nFileLength); jxP;>K7O
$ux,9H'[
+*\u :n
return nFileLength; goLL;AL
} 3_C|z,\:
hMa]B*o/-
y>S.?H:P
//保存下载信息（文件指针位置） W}nlRbN?
private void write_nPos() 50"pbzW
{ >R|/M`<ph
try{ n"$jG:AQJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); R%Hi+#/dr-
output.writeInt(nStartPos.length); m\;R2"H%
for(int i=0;i<nStartPos.length;i++) M+-*QyCFK
{ adlV!k7RG
// output.writeLong(nPos); r^2p*nr}
output.writeLong(fileSplitterFetch.nStartPos); I"xo*}
output.writeLong(fileSplitterFetch.nEndPos); BIH-"vTy
} O6@j &*jS
output.close(); HUcq%.
} 6 [k\@&V-
catch(IOException e){e.printStackTrace ();} .4S.>~^7
catch(Exception e){e.printStackTrace ();} ]z;P9B3@&
} 6S},(=
NxfOF
H!c@klD
//读取保存的下载信息（文件指针位置） } FE>|1
private void read_nPos() i)\L:qF5
{ m.hkbet/R
try{ V#v`(j%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b}\N;D.{
int nCount = input.readInt(); QZ!Y2Bz(4
nStartPos = new long[nCount]; 6=kEyJT'
nEndPos = new long[nCount]; +u.1 ;qF
for(int i=0;i<nStartPos.length;i++) \c,ap49RC
{ >3ZFzh&OYQ
nStartPos = input.readLong(); f}6s Q5
nEndPos = input.readLong(); o5d%w-'
} tE.FrZS
input.close(); /{Is0+)
} ag;Q F
catch(IOException e){e.printStackTrace ();} qjc8fP2
catch(Exception e){e.printStackTrace ();} Y&`=jDI
} W'els)WJ|x
u^&A W$
vjLJinJ/
private void processErrorCode(int nErrorCode) }pDqe;a{
{ XWDL5K
System.err.println("Error Code : " + nErrorCode); Ltv]pH}YN
} =pr`'
"7U4'Y:E
}I2wjO
//停止文件下载 &)2i[X
public void siteStop() oVnvO iAc
{ 60P<4
bStop = true; "33Fv9C#bK
for(int i=0;i<nStartPos.length;i++) rUwZMli
fileSplitterFetch.splitterStop(); bw(a6qKK
#:jHp44J
V4hiGO[
} Fiv3 {.
} G, 44va
//负责部分文件的抓取 p5Z"|\
**FileSplitterFetch.java <5d~P/,
*/ YD<:,|H
package NetFox; Moy <@+
svsqg{9z
@>u}eB>Kn
import java.io.*; ,NOsFO-`<
import java.net.*; ~Io7]
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Yf:IKY
public class FileSplitterFetch extends Thread { Wfu(*
'>NCMB{*
7X`l&7IXP
String sURL; //File URL bW$,?8(
long nStartPos; //File Snippet Start Position u6?Q3 bvI
long nEndPos; //File Snippet End Position XYjV.j\
int nThreadID; //Thread's ID H >j
boolean bDownOver = false; //Downing is over \4&fxe
boolean bStop = false; //Stop identical u&^b~#T
FileAccessI fileAccessI = null; //File Access interface i=ea ?eT`
{mm)ay|M
dFRsm0T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rr+|Zt Y
{ FFl!\y*0z
this.sURL = sURL; cIUHa
this.nStartPos = nStart; &[_g6OL
this.nEndPos = nEnd; Jk&3%^P{m
nThreadID = id; neB\q[k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d.3E[AJa(
} eS{!)j_^
k\wW##=v
$}RJ,%~'x
public void run() bG7O
{ O80<Z#%j`
while(nStartPos < nEndPos && !bStop) @>u]4Jn
{ 6,o~\8ia
|_LU~7./
r/4``shg
try{ gGvz(R:y
URL url = new URL(sURL); c*(bO3 b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |^0XYBxQ
httpConnection.setRequestProperty("User-Agent","NetFox"); H]P. x!I
String sProperty = "bytes="+nStartPos+"-"; T,7Y7c/3V
httpConnection.setRequestProperty("RANGE",sProperty); _7<FOOM%8y
Utility.log(sProperty); J{'>uD.@
.nB0 h
83E7k]7]
InputStream input = httpConnection.getInputStream(); RtGWG*v4]
//logResponseHead(httpConnection); u0 P|0\
~F7-HaQJ
uYn_? G
byte[] b = new byte[1024]; zxJ]"N
int nRead; TBs|r#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3Iua*#<m,
{ wE[]6\_x1
nStartPos += fileAccessI.write(b,0,nRead); <_h~w}
//if(nThreadID == 1) _+p4Wvu~0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MV<^!W
} +$u$<z3Q
g@rb
VkvB<3
Utility.log("Thread " + nThreadID + " is over!"); YbR!+ 0\g
bDownOver = true; +lm{Olm'^
//nPos = fileAccessI.write (b,0,nRead); 4F)-"ck
} RwKdxK+;
catch(Exception e){e.printStackTrace ();} Mc=$/ o
} mN~ci 0
} 3)8QS
34z"Pm
io _1Y]N
//打印回应的头信息 XnDUa3
public void logResponseHead(HttpURLConnection con) K:!"+q
{ V\{clJ\U
for(int i=1;;i++) ~s% Md
{ q_TRq:&.
String header=con.getHeaderFieldKey(i); MTsM]o
if(header!=null) ?: N@!jeJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); M}d_I+
Utility.log(header+" : "+con.getHeaderField(header)); ahuGq'
else ?/BqD;{?I
break; wr5AG<%(
} +s(HOq)b
} &]8P1{
9zZr^{lUl
r) HHwh{9
public void splitterStop() !LggIk1
{ 'L 8n-TyL
bStop = true; }&/o'w2wY
} qo p^;~
B$-R-S6
&7<TAo;O
} `JOOnTenQ
yXz*5W_0D
mX_a^_[G
/* ^.KwcXr
**FileAccess.java ?>hPO73{
*//文件访问(定位，写) ~kShq%
package NetFox; ;hYS6
import java.io.*; 6;u$&&c(
3 N.~mR
L_vISy%\b
public class FileAccessI implements Serializable{ U[SaY0Z
I`p+Qt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C3eR)Yh
RandomAccessFile oSavedFile; Inn@2$m~
long nPos; T@G?t0
m=?KZ?U`
w,w{/T+B
public FileAccessI() throws IOException j:5=s%S
{ :ZTc7}
this("",0); :axRoRg
} xGu r
PfreAEv,
5i>$]*o
public FileAccessI(String sName,long nPos) throws IOException GKOD/,
{ D&/kCi=R
oSavedFile = new RandomAccessFile(sName,"rw"); h?rp|uPQ
this.nPos = nPos; 'h/CoTk@,
oSavedFile.seek(nPos); .l>77zM6
} I Y2)?"A
4xk|F'6K
uv=.2U46
public synchronized int write(byte[] b,int nStart,int nLen) UF?H>Y&
{ iTFdN}U
int n = -1; )0ea+ib
try{ (5#nrF]
oSavedFile.write(b,nStart,nLen); NPCs('cd>?
n = nLen; N03HQp)g
} 2r!s*b\Ix
catch(IOException e) Zw*v
{ )^m%i]L_
e.printStackTrace (); 4#ug]X4Y')
} 8)O[Aq::
bu |a0h7e
ERpnuMb
return n; l;JA8o\x
} crqpV F]1]
V=zi >o`
Y,WuBH
} #cnq(S=.
V^JV4 `o
N F2/B#q
/* S'A>2>
**SiteInfoBean.java (5R?#vj
*/ +s,Qmmb7)
package NetFox; /4c\K-Z;
Jd%H2`
Fz1_w$^
public class SiteInfoBean { f#?fxUH~
I|>^1kr8w
94+KdHAo^M
private String sSiteURL; //Site's URL wT `a3Ymm
private String sFilePath; //Saved File's Path Q7R~{5r>W
private String sFileName; //Saved File's Name ZT,B(#m
private int nSplitter; //Count of Splited Downloading File T? tG~
j:k[90
'`eO\huf
public SiteInfoBean() KMU4n-s"o
{//nSplitter的缺省值为5 I2 j}Am
//default value of nSplitter is 5 4G$|Rx[{,
this("","","",5); ]3VI|f$$
} <1FC%f/
E0u~i59Z
D[^m{ 9_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5!l0zLQPo
{ _{r=.W+w
sSiteURL= sURL; RT)d]u
sFilePath = sPath; <z]cyXv/
sFileName = sName; J13>i7]L%
this.nSplitter = nSpiltter; hJDi7P
<4_X P.N
5#> 8MU?&
} #gp,V#T
MKy[hT:
}*lUah,@
public String getSSiteURL() +w.JpbQ&
{ >c9a0A
return sSiteURL; nx8a$vI-TY
} #tZ4N7
|55N?=8
/G5d|P
public void setSSiteURL(String value) |_`E1Y}}
{ R$[#+X!
sSiteURL = value; h&`e) a>+
} Hz.(qW">5*
5$wpL(:R(
:|Ad:fEs
public String getSFilePath() e '2F#
{ 89\n;5'f4
return sFilePath; Ytz)d/3T
} bty/
#bl6sa{E
#;%JT
public void setSFilePath(String value) kMtwiB|7j
{ x9;gT&@H
sFilePath = value; EGZb7:Y?
} O9EKRt
I9:Cb)hbU]
l~6?kFy9h
public String getSFileName() >p.O0G gg
{ uoHNn7W
return sFileName; %,D<O,N
} &jsVw)Ue
y($%;l
t%'Z<DmG+
public void setSFileName(String value) gF[z fDm
{ $: ]o]a
sFileName = value; FI3)i>CnW
} 4$*%gL;f^
zgs(Dt;
g>dA$h%
public int getNSplitter() %n hm
{ c0hwc1kv-
return nSplitter; n@U n
} f}1&HI8r
:{IO=^D=$
l-ct?T_@
public void setNSplitter(int nCount) &_"]5/"(
{ ]`&Yqg
nSplitter = nCount; B x (uRj
} ?Rj~f{%g
} hir4ZO%Zt
\T<$9aNb
Gm(b/qDDe
/* Kj<^zo%w
**Utility.java ^}:#
*/ 3'^k$;^
package NetFox; 6xZ=^;H
tQH+)*
b|+wc6
public class Utility { 2Z3('?\z~
U2`'qsR1
Q5FM8Q
public Utility() #m[|2R
{ *cC_j*1@
rFC" Jx
"g'jPwFG
} J41G&$j(
9nH?l{As
//线程睡眠 GKoK7qH\J
public static void sleep(int nSecond) (rkU)Q
{ wc!onZX5
try{ L+'Fs
Thread.sleep(nSecond); xo&]RYG[<
} ]79:yMD~ba
catch(Exception e) ox%9Ph
{ N_pJk2E
e.printStackTrace (); 1qf!DMcdZ
} oiX+l5`pz
} tl><"6AIP
Clh!gpB c
//日志 <<i3r|}
public static void log(String sMsg) BQ @huns3
{ T'LIrf
System.err.println(sMsg); 7c~u=U"
} +reor@h
~i21%$
i:u1s"3~
public static void log(int sMsg) [+OnV&
{ D<V~f B
System.err.println(sMsg); =e8bNg
} 2'5]~
} vq!_^F<
7f~Sf
Op>%?W8/UF
/* *P#WDXRwd
**TestMethod.java ?}m']4p
*/ Q4*fc^?u
package NetFox; jq+A-T}@
$d,0=Ci
JB>b`W9
public class TestMethod { A0fFv+RN3
(sQr X{~
'sxNDnGg
public TestMethod() {'AWZ(
{ ///xx/weblogic60b2_win.exe ;q:jl~
try{ ?gwUwOV"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i| ZceX/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >5j<4ShW
SiteFileFetch fileFetch = new SiteFileFetch(bean); #?XQ7Im
fileFetch.start(); l2&`J_"
} #hlCs
catch(Exception e){e.printStackTrace ();} ^k Cn*&
aM{xdTYaU
&m[Qn!>i6
} 1ylk4@`
M4d47<'*~
{U84 _Pi
public static void main(String[] args) U-:ieao@
{ )x]3Zq
new TestMethod(); F*.g;So
} gl]E_%tH
} iC*F
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