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)); L?j0t*do
} j(Lz& *4
for(int i=0;i<nEndPos.length-1;i++) jkx>o?s)z
{ jel:oy|_
nEndPos = nStartPos[i+1]; Ig t*8px
} C[<}eD4bV
nEndPos[nEndPos.length-1] = nFileLength; {KNaJ/:>W
} \^*:1=|7u]
} $j.;$~F
_i}b]xfM
I09 W=
//启动子线程 O{_t*sO9q*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vt{[_L(h
for(int i=0;i<nStartPos.length;i++) r=5S0
{ )0-A;X2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ea"X$<s>-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1hY|XZ%qd
nStartPos,nEndPos,i); | J3'#7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vml 6\X
fileSplitterFetch.start(); wn5OgXxG<
} "D _r</b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =^rt?F4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lc[6Mpi7s[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nsRCDUCi
nEndPos = " + nFileLength); xqzeBLU
// fileSplitterFetch[nPos.length-1].start(); .DhI3'Jrl
@01.Pd
iHGVR
//等待子线程结束 UeO/<ml3>J
//int count = 0; VKDOM0{V
//是否结束while循环 P}}G9^
boolean breakWhile = false; d\JaYizp
\{@m
k_,7#:+
while(!bStop) QQS*r}>
{ YWK0.F,8a
write_nPos(); =U3S"W %
Utility.sleep(500); =O }^2OARo
breakWhile = true; s#s">hMrI
%6320 x
%NrH\v{7Q
for(int i=0;i<nStartPos.length;i++) ?.SGn[
{ b!]O]dk#
if(!fileSplitterFetch.bDownOver) (p[#[CI9
{ ,Q-,#C"
breakWhile = false; l&ueD&*4&
break; PaI\y!f
} TRGpE9i
} ChTq!W
if(breakWhile) CW+kKN
break; Vc(4d-d5
R.rch2
_d@YLd78P
//count++; ; BN81;
//if(count>4) ~a([e\~
// siteStop(); ed,A'S=d
} T/3LJGnY
vTK%4=|1}!
}ssV"5M
System.err.println("文件下载结束！"); >[;W~*
} -wXeue},>
catch(Exception e){e.printStackTrace ();} Mp`$1Ksn
} {$z54nvw$
,p d-hu
A3a//e
//获得文件长度 qLmzA@Cv
public long getFileSize() m !*F5x
{ BYq80Vk%@
int nFileLength = -1; mKZzSd)p
try{ 3J#LxYK
URL url = new URL(siteInfoBean.getSSiteURL()); ty,oj33
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?XHQdN3e
httpConnection.setRequestProperty("User-Agent","NetFox"); e]RzvWq
a<<4gXx
]@#9B>v=
int responseCode=httpConnection.getResponseCode(); |fgUW.
if(responseCode>=400) \_`qon$9
{ \jiE:Qt
processErrorCode(responseCode); |SkQe[t
return -2; //-2 represent access is error OT 0c5x
} I_r@Y:5{
Me.I>7c
s(=wG|
String sHeader; $X#y9<bW
<N vw*yA
Vgm'&YT
for(int i=1;;i++) IEhD5?
{ |8k1Bap`z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Kv| x -_7
//Utility.log(in.readLine()); 0SI@`C*1o
sHeader=httpConnection.getHeaderFieldKey(i); 1B4Qj`:+0
if(sHeader!=null) PR@6=[|d
{ KR>)Ek
if(sHeader.equals("Content-Length")) Iq+N0G<j
{ Pf[E..HF*d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ol>q(-ea
break; PFJ$Ia|
} axnlI*!
} aJ+V]WmA
else (Mk7"FC7
break; V'i-pn2gyu
} '#+&?6p
} 0vv~G\yM
catch(IOException e){e.printStackTrace ();} 0nb%+],pX
catch(Exception e){e.printStackTrace ();} TF8#I28AD
^p3GT6
"W7|Xp
Utility.log(nFileLength); `WayR^9
ab6I*DbF
''nOXl
return nFileLength; h$02#(RHJ
} )=5&Q
Pu3oQDldV
[~9UsHfH
//保存下载信息（文件指针位置） O52/fGt
private void write_nPos() x"b'Pmw
{ DG;7+2U
try{ C8-7XQ=B:b
output = new DataOutputStream(new FileOutputStream(tmpFile)); <w9~T TS
output.writeInt(nStartPos.length); cXb*d|-|N
for(int i=0;i<nStartPos.length;i++) o!tC{"g
{ K?uZIDo
// output.writeLong(nPos); +x2JC' -H
output.writeLong(fileSplitterFetch.nStartPos); CYaN;HV@_
output.writeLong(fileSplitterFetch.nEndPos); 7X>IS#W]
} q_b!+Y
output.close(); <A,V/']
} `==l2AX
catch(IOException e){e.printStackTrace ();} XO <0;9|
catch(Exception e){e.printStackTrace ();} ME)Tx3d
} .ck?JXg
4mvR]:G
oqJYbim
//读取保存的下载信息（文件指针位置） EOB8|:*
private void read_nPos() b >D
{ uVEJV |^/
try{ 27SHj9I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hN3FH#YO
int nCount = input.readInt(); r)^sHpK:`
nStartPos = new long[nCount]; : B^"V\WE
nEndPos = new long[nCount]; |&#N&t
for(int i=0;i<nStartPos.length;i++) q94;x|63
{ ;%e)t[5
nStartPos = input.readLong(); 4LTm&+(5
nEndPos = input.readLong(); %,T*[d&i
} ;iKLf~a a
input.close(); p{w-
} Tdi^P}i_
catch(IOException e){e.printStackTrace ();} =~;~hZj
catch(Exception e){e.printStackTrace ();} .a@12J(I
} V%8(zt
mUg :<.^
^%7(
private void processErrorCode(int nErrorCode) ]rv\sD`[
{ !6(3Y
System.err.println("Error Code : " + nErrorCode); qZd*'ki<
} `Z;Z^c
'[#y|
Q!+AiSTU
//停止文件下载 vG_R( ]d
public void siteStop() @62,.\F
{ GAj%o]}u
bStop = true; Blxa0&3
for(int i=0;i<nStartPos.length;i++) od)TQSo
fileSplitterFetch.splitterStop(); &s".hP6
zH]oAu=H
e0P[,e*0
} q/b+V)V
} IhNX~Jg'^
//负责部分文件的抓取 5MnP6(3$
**FileSplitterFetch.java l2Sar1~1
*/ JQ%hh&M\0
package NetFox; cACIy yQ
KL_/f
!yd B,S
import java.io.*; d0>U-.
import java.net.*; ce;7
HP8J\`
r XJx~ g
public class FileSplitterFetch extends Thread { _KM? ?&
}B-$}
lUu0AZQmG
String sURL; //File URL ;^ME
long nStartPos; //File Snippet Start Position NVMn7H}>
long nEndPos; //File Snippet End Position B'yjMY![
int nThreadID; //Thread's ID [BE_^d5&
boolean bDownOver = false; //Downing is over => (g_\
boolean bStop = false; //Stop identical R0Vt_7
FileAccessI fileAccessI = null; //File Access interface Eg)24C R 4
(%B{=w}8
`H! (hMMV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?,pwYT0g
{ q=X<QhK
this.sURL = sURL; "KIY+7@S}
this.nStartPos = nStart; hju^x8 ,=m
this.nEndPos = nEnd; Fe!MA
nThreadID = id; 8$}<4 `39
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NVM_.vL
} % G=cKM
a/V,iCiH
hi"C<b.
public void run() +@rFbsyJ.
{ 5=?P6I_$G
while(nStartPos < nEndPos && !bStop) hQ|mow@Zmz
{ 5k0iVpjQ
_m9k2[N!
bYP8
try{ AY52j
URL url = new URL(sURL); IS]A<}j/-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HUx`RX0>
httpConnection.setRequestProperty("User-Agent","NetFox"); 8!2)=8|f
String sProperty = "bytes="+nStartPos+"-"; sOLh'x f.
httpConnection.setRequestProperty("RANGE",sProperty); 2_wpj;E
Utility.log(sProperty); *HD(\;i-$
M`&t=0D
-PPwX~;!
InputStream input = httpConnection.getInputStream(); Z,)H f
//logResponseHead(httpConnection); +v B}E
2'fd4rE5
O!"K'Bm
byte[] b = new byte[1024]; :tZsSK
int nRead; dUv@u!}B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wH|%3@eJ
{ cP?GRMX@}
nStartPos += fileAccessI.write(b,0,nRead); y[i}iT/~
//if(nThreadID == 1) c[-N A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7rdmj[vu
} Nr*l3Z>LD
LgF?1?
QP'sS*saJ
Utility.log("Thread " + nThreadID + " is over!"); ?6_]^:s
bDownOver = true; &oMEz 0
//nPos = fileAccessI.write (b,0,nRead); i431mpMa
} T:Cq}4k<
catch(Exception e){e.printStackTrace ();} &oG>Rqkm
} G u`xJ
} WHC/'kvF
r-T1^u
`<tRfl}qs
//打印回应的头信息 Tt~4'{Bc
public void logResponseHead(HttpURLConnection con) yP]>eLTSd
{ /H<{p$Wd
for(int i=1;;i++) HAH\#WE
{ 1`?o#w
String header=con.getHeaderFieldKey(i); j& 7>ph
if(header!=null) ;!HQ!#B
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }Q`+hJ0
Utility.log(header+" : "+con.getHeaderField(header)); [x)T2sA
else #K^hKx9
break; 3f5YPf2u
} %X_A#9
} ' wl})
nT|WJ%
)cH\i91
public void splitterStop() O]XRalkEM
{ sNx_9pJs4
bStop = true; W7!Rf7TK
} - egTZW-
uYebRCdR
K["rr/
} S5JMt;O
)L&y@dy)
w yxPvI`
/* |r+ x/,2-
**FileAccess.java 4]1/{</B|
*//文件访问(定位，写) 6?,qysm06
package NetFox; ?sHZeWZ(
import java.io.*; g}`g>&l5
"vk]y
f8-`bb
public class FileAccessI implements Serializable{ 2}<tzDI'
N%Bl+7,q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B\ 'rxbH
RandomAccessFile oSavedFile; CY?J$sN
long nPos; EC\@$Fg
$x}R2
{ 5r]G
public FileAccessI() throws IOException /'8%=$2Kw
{ /[ m7~B]QE
this("",0); T ?Om]:j
} qVU<jt
P:g!~&Q
\:h7,[e
public FileAccessI(String sName,long nPos) throws IOException &</)k|.A6\
{ lfBCzxifC
oSavedFile = new RandomAccessFile(sName,"rw"); `0ZH=*P
this.nPos = nPos; pOK=o$1V8
oSavedFile.seek(nPos); ;ZB=@@l(
} Vw;iE=L
0VvY(j:hp
~d&&\EZ
public synchronized int write(byte[] b,int nStart,int nLen) &DGqY5=
{ G!`%.tH
int n = -1; zji9\
try{ eLT3b6'"?
oSavedFile.write(b,nStart,nLen); i$pUUK
n = nLen; X,3"4 SK
} YAR$6&
catch(IOException e) ExS&fUn`C
{ !ldE9 .
e.printStackTrace (); ~98q1HgS]D
} #U0| j?!D
T.De1Q|
~7aD#`amU
return n; kPOk.F%)
} HpbwW=;V
TS#1+f]9J<
=_&,^h@'3e
} 3^Is4H_8
tY#&_%W
u9:sj
/* oG22;
**SiteInfoBean.java \>su97
*/ ,ng/T**@G
package NetFox; PUea`rE?R
]l }v
^Zs^
public class SiteInfoBean { =l2 @'YQ
W\Il@Je;
9Cd=^Im5
private String sSiteURL; //Site's URL Qv,ORm h5
private String sFilePath; //Saved File's Path f`vWCb
private String sFileName; //Saved File's Name vy [7I8f{
private int nSplitter; //Count of Splited Downloading File c-zW 2;|61
jB -Ad8
B$c'^ )
public SiteInfoBean() #U'}g *
{//nSplitter的缺省值为5 H^*[TX=#[
//default value of nSplitter is 5 CWZv/>,%
this("","","",5); Z3zD4-p$_
} [)}`w;#
UptKN|S&V
x15&U\U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %eF=;q
{ k FRVW+
sSiteURL= sURL; @ #J2t#
sFilePath = sPath; V#599-
sFileName = sName; 0XE6Hw
this.nSplitter = nSpiltter; %b pQ=
Hv"qRuQ?[
z+fy&NPl
} \xOYa
4EeVO5
aa]|
public String getSSiteURL() U0|wC,7"
{ <_8eOL<X
return sSiteURL; 1Xcj=I-4
} Mj0jpP<uf
xE_~.EoB
</9c=GoJ
public void setSSiteURL(String value) BDL[C<d(
{ (eT9N_W
sSiteURL = value; 5!i\S[:
} "@+Z1k-8U
CC6]AM(i
3kr.'O
public String getSFilePath() UM1h[#?&V)
{ d|tNn@jN
return sFilePath; z\k6."e_&
} ^~B#r#
WYvcN8F
f#38QP-T
public void setSFilePath(String value) <@>icDFEHn
{ gBgaVG
sFilePath = value; G #$r)S
} 2zsDb'r
$*fEgU% c
TD;u"
public String getSFileName() OS~Z@'Eg
{ BMzS3;1_
return sFileName; j%S} T)pX
} mg3YKHNG
ZV/g_i#
9-Qu5L~
public void setSFileName(String value) Ta8lc %0w3
{ %Q93n {?
sFileName = value; ,=u!hg
} LK|rLoia:
xs)SKG*
O8*yho
public int getNSplitter() 1OFrxSg
{ z4[8*}
return nSplitter; /GP:W6:6z6
} ^x >R #.R
RLh%Y>w
#FGj)pu
public void setNSplitter(int nCount) MR":aT
{ [r1\FF@v,
nSplitter = nCount; > W^"*B
} )P W Zc?M
} w`Cs,
{bNKyT
n7#}i2:
/* R4f_Kio
**Utility.java G7#<Jo<8
*/ mj& 4FQ#O*
package NetFox; t%s(xz#1
e>HdJ"S`
t; #D,gx
public class Utility { ?D@WXE0a
cS|W&IH1
%&$s0=+
public Utility() p^QppM94
{ $.Qq:(O:6
d-UQc2r
Eye.#~
} dr=h;[Q'
?&XpwJw:~
//线程睡眠 8}OII\
public static void sleep(int nSecond) [@/x
{ =W'{xG}
try{ y(6*)~Dh
Thread.sleep(nSecond); h"$],=
} K"=I,Vr:
catch(Exception e) /n1H;~f]
{ 0e~4(2xK
e.printStackTrace (); Q$S|LC
} D14i]
} qAVZ&:#
Z&Z=24q_
//日志 w"FBJULzn9
public static void log(String sMsg) "&TN}SBW
{ wn>?r ?KIB
System.err.println(sMsg); lDtl6r/
} *46hw(L
ET=-r
{r[g.@
public static void log(int sMsg) li)shp)
{ :}~B;s0M\
System.err.println(sMsg); ,uhOf! |
} zqGo7;;#
} m^YYdyn]M
Cq%1j[
iy,jq5uw
/* j !rQa^
**TestMethod.java ":Ll.=!
*/ uKpWb1(
package NetFox; OR-fC
/U,;]^
\QMRuR.
public class TestMethod { mT#ebeBaf
>}!})]Xw9
`BKV/Xl
public TestMethod() p>0n~e
{ ///xx/weblogic60b2_win.exe y(Ck j"
try{ `Ct fe8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %b3s|o3An
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &/]g@^h9
SiteFileFetch fileFetch = new SiteFileFetch(bean); )p+6yH
fileFetch.start(); $n9Bp'<
} {-e|x&-
catch(Exception e){e.printStackTrace ();} T.#Vma
L3^+`e
5(&'/U^
} U=\!`_f':
lX|d:HFtP
"midC(rTm
public static void main(String[] args) ^q)s
{ l]__!X
new TestMethod(); #TKByOcD2!
} 3Ay<2v
} -|3feYb'
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