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)); Qhj']>#g
} 1i#y>fUj
for(int i=0;i<nEndPos.length-1;i++) 0PkX-.
{ i`+w.zJOH8
nEndPos = nStartPos[i+1]; qiet<F
} 9JdJn>
nEndPos[nEndPos.length-1] = nFileLength; k[8F: T-
} {H/%2
} I7_8oq\3D
k<1i.rh
2{j$1EdI@-
//启动子线程 L]MWdD
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K^!#;,0
for(int i=0;i<nStartPos.length;i++) $]LS!@ Rm
{ 0m3hL~0(a
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zv}F?4T~:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), brTNwRze
nStartPos,nEndPos,i); H|aFs.SEQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b"$?(Y
fileSplitterFetch.start(); _o9axBJs
} ?jR#txR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `i.fm1I]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W_@ b. 1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @A6iY
nEndPos = " + nFileLength); s={>{,E
// fileSplitterFetch[nPos.length-1].start(); `!cdxKLR
#;8)UNc)}
_jX,1+M
//等待子线程结束 `LoRudf_`
//int count = 0; 5=V"tQ&d9U
//是否结束while循环 9<3( QR
boolean breakWhile = false; Tbm ~@k(C
Osz=OO{
#[bosb!R
while(!bStop) )bg|l?
{ M IIa8;
write_nPos(); oO;L l?~
Utility.sleep(500); 3!9JXq%Hl
breakWhile = true; M_!]9#:K7
d21thV ,S
2D%2k
for(int i=0;i<nStartPos.length;i++) BPj?l
{ ~j[?3E4L}
if(!fileSplitterFetch.bDownOver) G$a@}9V
{ Y*@7/2,
breakWhile = false; fK:4jl-r
break; (87wWhH
} z#!<[**&
} Aq(cgTNW
if(breakWhile) I'IFBVhaYn
break; GDCp@%xW
ga|<S@u?}
%( OP [
//count++; n=j)M
//if(count>4) K^o$uUBe
// siteStop(); IwYfs]-
} zx<t{e7
gH7 +#/
\j!/l f)
System.err.println("文件下载结束！"); 0m1V@3]7>
} _v#puFy
catch(Exception e){e.printStackTrace ();} egsP\ '
} &PXT$x[i
I+Fy)=DO9
p[&Jl
//获得文件长度 S8qg"YR
public long getFileSize() }Nn+Ny
{ 8/p ]'BLf
int nFileLength = -1; =xkaF)AW&v
try{ PW@ :fM:q
URL url = new URL(siteInfoBean.getSSiteURL()); [>`.,k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W'9{2h6u(
httpConnection.setRequestProperty("User-Agent","NetFox"); TAh'u|{u2
H,c1&hb/w
*-*V>ntvT$
int responseCode=httpConnection.getResponseCode(); _886>^b@
if(responseCode>=400) RCfeIHL
{ >A{e,&
processErrorCode(responseCode); Z?S?O#FED
return -2; //-2 represent access is error Ru d9l.n
} R<1%Gdz
waz5+l28
d(}? \|
String sHeader; Ag T)J
Mh3.GpS
Wj3i*x$
for(int i=1;;i++) [[_>DM
{ Z[[*:9rY|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '9]?jkl
//Utility.log(in.readLine()); DCa[?|Y
sHeader=httpConnection.getHeaderFieldKey(i); i5(qJ/u
if(sHeader!=null) .qe+"$K'n
{ 3VU4E|s>
if(sHeader.equals("Content-Length")) #:=c)[G8
{ IJ+}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9Znc|<
break; b`%u}^B {
} <- sr&
} Zl%)#=kO
else V%[t'uh
break; fqbWD)L]
} 0X99D2c
} jSBz),.XU}
catch(IOException e){e.printStackTrace ();} { #B/4
catch(Exception e){e.printStackTrace ();} prM)t8SE
\aPH_sf,
A%EhRAy
Utility.log(nFileLength); 5G6 Pp7[
+EA ")T<l
F%zMhX'AG
return nFileLength; [,st: Y
} 3W ]zLUn
uN?Lz1W\;
Hwd^C2v
//保存下载信息（文件指针位置） VO1
private void write_nPos() }x$@j
{ dR i6
try{ xxzUey
output = new DataOutputStream(new FileOutputStream(tmpFile)); f }r \
output.writeInt(nStartPos.length); vC&0UNe$
for(int i=0;i<nStartPos.length;i++) 1r4NP
{ **-rPonM[
// output.writeLong(nPos); UazK0{t<f
output.writeLong(fileSplitterFetch.nStartPos); RJ3uu NK7
output.writeLong(fileSplitterFetch.nEndPos); 8|= c3Z
} =KO]w9+\
output.close(); @fA|y
} `B&E?x
catch(IOException e){e.printStackTrace ();} [A,!3BN
catch(Exception e){e.printStackTrace ();} /qKor;x
} VPYcA>-%u
gCYe^KJ
|H8C4^1Rq
//读取保存的下载信息（文件指针位置） [V /f{y~{
private void read_nPos() )6"p@1\u
{ BGVnL}0
try{ GLub5GrxR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7H6Ge-u
int nCount = input.readInt(); <:(;#&<
nStartPos = new long[nCount]; d|87;;X|u
nEndPos = new long[nCount]; VJA/d2Oys
for(int i=0;i<nStartPos.length;i++) AEf[:]i]
{ l'Li!u
nStartPos = input.readLong(); 'rXf
nEndPos = input.readLong(); f3vl=EA4|
} z+M{zr
input.close(); l`6.(6
} 5`}za-
catch(IOException e){e.printStackTrace ();} O)R}|
catch(Exception e){e.printStackTrace ();} Y]~-S
} ;j~%11
+p _?ekV\
EBWM8~Nm#
private void processErrorCode(int nErrorCode) _8SB+s*
{ {{bwmNv"
System.err.println("Error Code : " + nErrorCode); IrRe6nf@K
} F`F|.TX
Y1AZ%{^0a
7uUq+dp
//停止文件下载 7r3CO<fb
public void siteStop() r4K_Wp
{ @D["#pe,}
bStop = true; EAr;
for(int i=0;i<nStartPos.length;i++) ?|oN}y"i
fileSplitterFetch.splitterStop(); 1QhQ#`$<1
]p4?nT@]
S+Ia2O)BA
} ^v5]Aq~X
} ON{a'H
//负责部分文件的抓取 $B9?>a|{A
**FileSplitterFetch.java usKP9[T$
*/ DIP%*b#l$\
package NetFox; s9Tn|Pm+!\
?|NsaW
A3HNMz
import java.io.*; | h"$
import java.net.*; U7fNA7#x"
O\oRM2^u}
dA2@PKK
public class FileSplitterFetch extends Thread { Gys-Im6>~@
xz}CqPJ#
A#Ga!a
String sURL; //File URL V\n!?1{kdF
long nStartPos; //File Snippet Start Position uARkf'
long nEndPos; //File Snippet End Position N*PJ m6-
int nThreadID; //Thread's ID 3,!IV"_
boolean bDownOver = false; //Downing is over vN]_/T+
boolean bStop = false; //Stop identical R:'&>.AUw
FileAccessI fileAccessI = null; //File Access interface D5Jg(-
V2;Nv\J\
Az(,Q$"|5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gDw(_KC
{ &_@M 6[-
this.sURL = sURL; 7^@ 1cA=S
this.nStartPos = nStart; #PC*l\ )
this.nEndPos = nEnd; ())_4 <
nThreadID = id; !Dc;R+Ir0!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I"8Z'<|/\q
} ~rq:I<5
Xmb##:
Jp8,s%
public void run() I@Yk &aU
{ B"88 .U}$
while(nStartPos < nEndPos && !bStop) iYdg1
{ ;$]a.9 -
SN7_^F
/r&4< @
try{ -J'ked
URL url = new URL(sURL); pp#!sRUKPV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %k"hzjXAw
httpConnection.setRequestProperty("User-Agent","NetFox"); wT3D9N.
String sProperty = "bytes="+nStartPos+"-"; S,'ekWVD
httpConnection.setRequestProperty("RANGE",sProperty); c8_,S[W
Utility.log(sProperty); TgLr4Ex
?!c7Zx,(
o5+7Lt]
InputStream input = httpConnection.getInputStream(); $QT% -9&
//logResponseHead(httpConnection); E+ XR[p
7bVKH[
u#V;
byte[] b = new byte[1024]; gH"aMEC
int nRead; zT!.5qd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VsL*&Fk
{ )$pqe|,
nStartPos += fileAccessI.write(b,0,nRead); P;X0L{u0H
//if(nThreadID == 1) 6%o@!|=I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tp ky
} E=bZ4 /
={p<|8`"
bx7hQzoX=b
Utility.log("Thread " + nThreadID + " is over!"); 5yW}#W>
bDownOver = true; l r~>!O
//nPos = fileAccessI.write (b,0,nRead); >r4BI}8SK<
} u2':~h?l
catch(Exception e){e.printStackTrace ();} c*(=Glzn
} V6Of(;r
} b ts*qx&)
PKGqu,J,
)1YGWr;ykS
//打印回应的头信息 plzwk>b_
public void logResponseHead(HttpURLConnection con) Hg\H>Z
{ )wEXCXr!
for(int i=1;;i++) AGx(IK/_
{ 0G'v4Vj0'
String header=con.getHeaderFieldKey(i); sAK&^g
if(header!=null) dJb7d`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l{kacfk#
Utility.log(header+" : "+con.getHeaderField(header)); i4SWFa``
else M%!j\}2A
break; daf-B-
} `"xzC $
} 2@&"*1(Xu
0'zjPE#
~PN[ #e]
public void splitterStop() idS+&:'
{ )Dcee@/7S
bStop = true; Ghe@m6|D
} \pI ,6$'
3m~3l d
+\vN#xDz
} $ Fy)+<
Aq$o&t
[2 Rz8e^
/* "/hLZl
**FileAccess.java u b@'(*
*//文件访问(定位，写) %7Gq#rq
package NetFox; n*~#]%4
import java.io.*; v=IcVHuf
h}+Gz={Q^
tK\$LZ
public class FileAccessI implements Serializable{ (d[JMO^@8
E/d\ebX|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Hjy4tA7,l
RandomAccessFile oSavedFile; xfqu=z8X
long nPos; BK.RYSN
"(a}}q 9-
)9!J $q
public FileAccessI() throws IOException Y~OyoNu2
{ 7l'1
this("",0); ?CpM.{{s
} NL"w#kTc()
;tZ8Sh)
368H6 Jj
public FileAccessI(String sName,long nPos) throws IOException S~y.>X3"P
{ pTYV@5|
oSavedFile = new RandomAccessFile(sName,"rw"); Q0""wRq'
this.nPos = nPos; Mi[,-8Sk
oSavedFile.seek(nPos); ^687U,+
} T zHR
r+MqjdXG
:O*62olC5
public synchronized int write(byte[] b,int nStart,int nLen) Tz/[P:O3
{ 7{[i)
int n = -1; .R@euIva
try{ 3TKl
oSavedFile.write(b,nStart,nLen); EmV ZqW
n = nLen; 9lX+?m~ ~
} (=s%>lW|
catch(IOException e) %S%0/
{ ?zK>[L
e.printStackTrace (); g^k=z:n3,
} Z Mf,3
O$Dj_R#
J]&nZud`
return n; 2u}ns8wn
} ^cojETOv
/5:qS\Zl
@])}+4D(S
} \@j3/!=,n%
&$pA,Gjin\
i]zTY\gw8M
/* uU8L93
**SiteInfoBean.java ,j[1!*Z_[
*/ `$r?^|T
package NetFox; ,Q8h#0z r
w8-L2)Q}I
RSF@Oo{
public class SiteInfoBean { CSE!Abg
w"h'rw
m^a0JR}u9
private String sSiteURL; //Site's URL TfA;4^
private String sFilePath; //Saved File's Path &_Gu'A({J
private String sFileName; //Saved File's Name #U/L8
private int nSplitter; //Count of Splited Downloading File @<p9O0
3T@`VFbE
<kWNx.eci
public SiteInfoBean() I,?!NzB
{//nSplitter的缺省值为5 7FP @ vng
//default value of nSplitter is 5 +|spC
this("","","",5); ; 5!8LmZ0#
} ;:ocU?
l8N5}!N
x>[ gShAV!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A@I3:V
{ j!?bE3r~
sSiteURL= sURL; $b"Ex>
sFilePath = sPath; hmtDw,j
sFileName = sName; !9=Y(rb
this.nSplitter = nSpiltter; T;B/Wm!x
:J6FI6
}+ TA+;
} uulzJbV,K
)Z@hk]@?_[
Th5}?j7
public String getSSiteURL() ]\J(
{ E&|EokSyN
return sSiteURL; ?}U l(
} eLop}*k
.+CMm5T
>tV:QP]Y
public void setSSiteURL(String value) 78u=Jz6
{ /d1V&Lj
sSiteURL = value; _."X# }W
} V4x6,*)e
*|/kKvN
HAMps[D[
public String getSFilePath() uGS^*W$
{ >qynd'eToR
return sFilePath; l)91v"vJ
} VV=6v;u`
]hA]o7k
LfG$?<}hR
public void setSFilePath(String value) \!'K#%]9
{ +Ram%"Zwh
sFilePath = value; /Oa.@53tK6
} %'[ pucEF
e#{l
U\",!S~<
public String getSFileName() bn"z&g
{ ~1.~4~um
return sFileName; ;WsV.n
} fn\&%`U
Zq"wq[GCN
A/*h[N+2!
public void setSFileName(String value) *Ja,3Qq
{ 0'tm.,
sFileName = value; n(el
} :Nw7!fd
#+PfrS=
82Nw6om6i
public int getNSplitter() 08E,U
{ 5%(xZ 6
return nSplitter; B?<Z(d7
} OL$^7FB
fsVr<m
u&ozc
public void setNSplitter(int nCount) bR? $a+a)
{ vke]VXU9z
nSplitter = nCount; d`4@aoM
} rwepe5
} FuZLE%gP
JQWW's}
vD4<G{
/* d9uT*5f
**Utility.java 9w,u4q
*/ Ry iS
package NetFox; p`LPO
cK+y3`.0
de?lO;8
public class Utility { oq}Q2[.b
vH9Gf
t>>\U X
public Utility() +S>}<OE
{ i3\6*$Ug
9k>=y n
|{@_J
} -)ag9{*
H>2f M^
//线程睡眠 7Ke#sW.HN
public static void sleep(int nSecond) Ty>g:#bogI
{ V{G9E
try{ vdN0YCXG
Thread.sleep(nSecond); 66~]7w
} Dhe ]f#d
catch(Exception e) -,#LTW<.
{ z;EnAy{9
e.printStackTrace (); l<mEGKB#
} k@= LR
} #5.L%F
:,(ZMx\
//日志 d[.JEgU
public static void log(String sMsg) (KxL*gB
{ 0Ku%9wh-
System.err.println(sMsg); HR83{B21
} ZM%z"hO9R
O6pL )6d
nob^ I5?
public static void log(int sMsg) [,fdNxc8
{ )\TI^%s
System.err.println(sMsg); ku}I;k |
} l6Q75i)eF
} #GHLF
]xIfgSq
[#R<Z+c
/* p@7[w@B\c
**TestMethod.java UPkD^D,
*/ .%4{zaB
package NetFox; R'q:Fc
;Q =EI%_tv
j\SW~}d9
public class TestMethod { yxa~Rz/
vYNh0)$%F
q:1_D>
public TestMethod() }[<eg>9#
{ ///xx/weblogic60b2_win.exe JDzkv%E^
try{ vK\;CSk
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RZ[r XV5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1Bz'$u;
SiteFileFetch fileFetch = new SiteFileFetch(bean); SdfrLdi}Y
fileFetch.start(); i%~4>k
} -vfV;+3
catch(Exception e){e.printStackTrace ();} ~4mgYzOmD`
fxQN
j}?O
} u= K?K
3a4 ]{
{O,Cc$_
public static void main(String[] args) %Iv0<oU
{ mdOF0b%-]
new TestMethod(); '* +]&~b
} k:w\4Oqd
} t$=0 C
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