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)); (1 "unP-
} N2?o6)
for(int i=0;i<nEndPos.length-1;i++) Vvth,
{ }Htnhom0n
nEndPos = nStartPos[i+1]; |Ef\B]Ns
} n21Pfig
nEndPos[nEndPos.length-1] = nFileLength; s`j QX\{
} 4(VVEe
} ho1Mo
vhw"Nl
A@8Ot-t:\2
//启动子线程 &C~R*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /Hox]r]'e
for(int i=0;i<nStartPos.length;i++) I)xB I~x
{ oD$8(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r/X4Hy0!lT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |ZEZ@y^
nStartPos,nEndPos,i); S$CO T)7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z7[TgL7
fileSplitterFetch.start(); K[wOK
} |x2+O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1'skCR|!<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _RLx;Tn)L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", HF9\SVR B
nEndPos = " + nFileLength); vybQ}dscn
// fileSplitterFetch[nPos.length-1].start(); yIab3/#`
9uXuV$.
IETdL{`~
//等待子线程结束 q P<n<
//int count = 0; Sv*@3x
//是否结束while循环 ISQC{K']J
boolean breakWhile = false; Kn9O=?Xh;
uS9:cdH
~R;9a"nr
while(!bStop) AML8.wJ
{ 16iymiLz&
write_nPos(); !Gv*iWg
Utility.sleep(500); _(CuuP$`I
breakWhile = true; /jR]sC)xs
i[:S *`@S
1E(~x;*)
for(int i=0;i<nStartPos.length;i++) N30w^W&
{ ]r#YU0
if(!fileSplitterFetch.bDownOver) g$&uD
{ -hM nA)+
breakWhile = false; }E01B_T9z
break; XA cpLj]
} ep"YGx[V
} UbBo#(TZ)
if(breakWhile) ;z6Gk&?
break; JvA6kw,
omxBd#;F$
T&?0hSYt
//count++; #n=b*.
//if(count>4) br!:g]Vh
// siteStop(); OL,3Jh% x
} DzZ)aE
G2FP|mf,
U Ox$Xwp5&
System.err.println("文件下载结束！"); -Jo8jE~>V
} -IBf;"8f
catch(Exception e){e.printStackTrace ();} Sm(QgZO[4
} _$<Q$P6y
M`W%nvEDE
'Ii%/ Ob!
//获得文件长度 (BtavE
public long getFileSize() s]=s2.=
{ 3xhv~be
int nFileLength = -1; !B=Oc!e=K
try{ ;WQ@dC
URL url = new URL(siteInfoBean.getSSiteURL()); "J0,SFu:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t@GPB]3[
httpConnection.setRequestProperty("User-Agent","NetFox"); A#s`!SNv
x\=2D<@az
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int responseCode=httpConnection.getResponseCode(); HaP0;9q
if(responseCode>=400) {HV$hU+_)Q
{ SZOcFmC?
processErrorCode(responseCode); :n3)vK
return -2; //-2 represent access is error 8S&Kf>D
} q!iMc
KRS_6G],{
],*^wQ
String sHeader; zNE"5
;().
*7"R[!9
for(int i=1;;i++) > ,L'A;c}
{ Oeo:V"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $}d| ~q\
//Utility.log(in.readLine()); Onr#p4UT
sHeader=httpConnection.getHeaderFieldKey(i); Luxo,Ve
if(sHeader!=null) U D9&k^
{ KtWG2
if(sHeader.equals("Content-Length")) ]w _,0q
{ 1Aq*|JSk(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )7mX]@
break; >wK ^W{
} r7tN(2;5
} SrV+Ox
else [\o+I:,}wi
break; h&7]Bp
} &Mset^o
} N0be=IO5#
catch(IOException e){e.printStackTrace ();} -e=p*7']
catch(Exception e){e.printStackTrace ();} _VU/j9<+
,}M@Am0~
ETP}mo
Utility.log(nFileLength); ({3hX"C@Q
"7R"(.~>
=RR225
return nFileLength; @l9qH1
} 0NLoqq
_C9*M6IU
KlgPDV9mg
//保存下载信息（文件指针位置） e&dE>m
private void write_nPos() QN[-XQ>Xt
{ )hH9VGZq(
try{ IAt;?4
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?^i$} .%W
output.writeInt(nStartPos.length); g-=)RIwm
for(int i=0;i<nStartPos.length;i++) :$&%Pxm
{ $tyF(RybG
// output.writeLong(nPos); +w Oa
output.writeLong(fileSplitterFetch.nStartPos); ,jWMJ0X/N=
output.writeLong(fileSplitterFetch.nEndPos); t&UPU&tY
} /#Y)nyE
output.close(); pv2_A
} .xT8@]
catch(IOException e){e.printStackTrace ();} s)$N&0\
catch(Exception e){e.printStackTrace ();} e";r_J3w
} U;n$
[GeJn\C_?
T>(nc"(
//读取保存的下载信息（文件指针位置） .I{b]6
private void read_nPos() ?45kN=%*s
{ ScrEtN
try{ 6JWCB9$4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k%\_UYa
int nCount = input.readInt(); **rA/*Oc
nStartPos = new long[nCount]; sDnHd9v<?t
nEndPos = new long[nCount]; &sL(|>N
for(int i=0;i<nStartPos.length;i++) @;}bBHQz{p
{ eqcV70E8cK
nStartPos = input.readLong(); %dTkw+J
nEndPos = input.readLong(); 66<3zadJZU
} SCk2D!u
input.close(); l-"c-2-!
} aH)$#6${Ap
catch(IOException e){e.printStackTrace ();} nAn/Vu
catch(Exception e){e.printStackTrace ();} @Md%gEh;&
} ]=p@1
'iO?M'0gE#
&~P5[[Q
private void processErrorCode(int nErrorCode) G#/}_P
{ $ WAFr
System.err.println("Error Code : " + nErrorCode); 8P r H"pI
} @NGK2J
>W"gr]R<
Ec| Gom?
//停止文件下载 q10gKVJum
public void siteStop() V,bfD3S3
{ THirh6
bStop = true; b:.aZ7+4
for(int i=0;i<nStartPos.length;i++) P0J3ci}^
fileSplitterFetch.splitterStop(); HlqvXt\
Ktg{-Xl
I0 a,mO;m
} v8"plx=3
} 8YC\Bw
//负责部分文件的抓取 >ir'v5
**FileSplitterFetch.java u2 a U0k:
*/ FR9<$
package NetFox; 3*$A;%q
@'U9*:}U
5Qhu5~,K
import java.io.*; ~dfc
import java.net.*; t>|Y-i3cb
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{hB7F"S
public class FileSplitterFetch extends Thread { <}-[9fW
Pg" uisT#>
brJ_q0@
String sURL; //File URL vz:P2TkM
long nStartPos; //File Snippet Start Position Ed9ynJ~)X
long nEndPos; //File Snippet End Position W HO;;j
int nThreadID; //Thread's ID }l&Uh&B`
boolean bDownOver = false; //Downing is over Vh^fbv`?
boolean bStop = false; //Stop identical yfeX=h
FileAccessI fileAccessI = null; //File Access interface )n 1b
\B"5 Kp<
Z<ozANbk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oK&LYlU
{ c%v[p8 %
this.sURL = sURL; T1hr5V<U
this.nStartPos = nStart; ~U`oew
this.nEndPos = nEnd; B"TZ8(<
nThreadID = id; k|Vq-w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 / <WB%O
} /]_T
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^RytBwzKM
public void run() Rk.YnA_J6
{ o^;$-O!/
while(nStartPos < nEndPos && !bStop) 6H67$?jMyJ
{ <jF]SN
$.kP7!`:,
yC !`6$
try{ wXp A1,i
URL url = new URL(sURL); '/U[ ui0{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~n%~ Z|mMF
httpConnection.setRequestProperty("User-Agent","NetFox"); xaSvjc\
String sProperty = "bytes="+nStartPos+"-"; <y=VDb/
httpConnection.setRequestProperty("RANGE",sProperty); `,d*>
Utility.log(sProperty); X=_pQ+j`^
aYr?J Ol
02:]
InputStream input = httpConnection.getInputStream(); E%OY7zf`%
//logResponseHead(httpConnection); e>~g!S}G
G$pTTT6#
$,q~q^0
byte[] b = new byte[1024]; Htn=h~U`z
int nRead; jW*|Mu>2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TjxZ-qw<
{ %`%oupqm+
nStartPos += fileAccessI.write(b,0,nRead); !"/]<OQ
//if(nThreadID == 1) 3^ ~M7=k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); By{zX,6'
} A<l8CWv[
}]_/:KUt
aAZS^S4v
Utility.log("Thread " + nThreadID + " is over!"); r=P)iE:
bDownOver = true; l T~RH0L
//nPos = fileAccessI.write (b,0,nRead); r2}u\U4>
} =; Gw=m(
catch(Exception e){e.printStackTrace ();} Gm;)Om_
} Aifc0P-H
} \Km!#:
e5KsKzu a
$X8(OS5d'
//打印回应的头信息 ,#[0As29u
public void logResponseHead(HttpURLConnection con) W[BZ/
{ )=l~XV
for(int i=1;;i++) "a))TV%N
{ 1oD,E!+^d
String header=con.getHeaderFieldKey(i); E8gXa-hv
if(header!=null) B*btt+6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _#@n^c
Utility.log(header+" : "+con.getHeaderField(header)); k`JP
else ntbl0Sk
break; hc OT+L>
} L;zwqdI
} k8H@0p
{Vw+~8
CsHHJgx
public void splitterStop() r_nB-\
{ Qb<i,`SN
bStop = true; 's>
} &5puGnTZ
[P.M>"c\
j#QJ5(#
} P8!ON=
Ix@rn
/5Aum?~
/* eygmhaE
**FileAccess.java +\g/KbV7
*//文件访问(定位，写) X{4jyi-<
package NetFox; /a.4atb0
import java.io.*; ?q a
't:$Lx
!z">aIj\6
public class FileAccessI implements Serializable{ G2 A#&86J{
_DsA<SJ]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }5c%v1
RandomAccessFile oSavedFile; i!g}PbC[
long nPos; r09gB#K4
873$EiyXR
]j> W9n?
public FileAccessI() throws IOException hkV;(Fr&z
{ 0WT]fY?IS
this("",0); a(AKVk\
} 8*7t1$
.4on7<-a
0_'(w;!wq:
public FileAccessI(String sName,long nPos) throws IOException m,}0p
{ MU6|>{
oSavedFile = new RandomAccessFile(sName,"rw"); Zjqa n
this.nPos = nPos; )!6JSMS
oSavedFile.seek(nPos); <T]%Gg8
} },58B
0K/Pth"*
(:9yeP1
public synchronized int write(byte[] b,int nStart,int nLen) k(LZ,WSR
{ HJ#3wk"W
int n = -1; ,/0Q($oz
try{ $A~UA
oSavedFile.write(b,nStart,nLen); zVN/|[KP4
n = nLen; GL;@heP
} y/=:F=H@w
catch(IOException e) :})(@.H
{ Z]?Tx2|7
e.printStackTrace (); N(i%Oxp1
} .Zo%6[X
\:]
x{K^u"
return n; hojP3 [
} ,b[}22
$!Z><&^/
l{b<rUh5W
} s18o,Zs'
lGrp^
;:<z hO
/* 8VG6~>ux'>
**SiteInfoBean.java 3#GZ6:rVJ
*/ &\<!{Y<'
package NetFox; oh*Hzb
MTBHFjXO
@ig'CF%(
public class SiteInfoBean { _N8Tu~lqV
m]H[$Q
vTnrSNdSE
private String sSiteURL; //Site's URL x)evjX=q
private String sFilePath; //Saved File's Path A8,9^cQ]
private String sFileName; //Saved File's Name M)v\7a
private int nSplitter; //Count of Splited Downloading File ++O L&n
OJ#ehw<
j,<3[
public SiteInfoBean() W,sU5sjA
{//nSplitter的缺省值为5 D5]AL5=Xt2
//default value of nSplitter is 5 -64@}Ts*?
this("","","",5); /<[S> ;!kr
} &6]+a4
~K'e}<-G
feJzX*u
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9Z?P/ o
{ M:t!g%
sSiteURL= sURL; l^`& Tnzv
sFilePath = sPath; `Fn"%P!
sFileName = sName; Q`?+w+y7
this.nSplitter = nSpiltter; 'iQ
&d,chb(
~nit~;
} `As|MYv
D$X9xtT
:LE0_ .
public String getSSiteURL() lKVy{X3]*
{ j@chSk"K
return sSiteURL; ~kDR9s7
} '8%pEl^
+Dvdv<+
2Y~UeJ_\Lq
public void setSSiteURL(String value) ^b{-y
{ Kmy'z
sSiteURL = value; P9d%80(b4
} mM`zA%=
n oWjZ
}E o\=>l7
public String getSFilePath() PK&3nXF%4
{ C\-Abqc
return sFilePath; FEOr'H<3x
} L >* F8|g
+SM&_b
9gu$vF]9!
public void setSFilePath(String value) w$5~'Cbi
{ :+ASZE.
sFilePath = value; U2Uf69R
} z@70{*
bxxazsj^
A%Ov.~&\G
public String getSFileName() O &/9wi>!q
{ r'TxYM-R
return sFileName; [_$r-FA
} :eK(9o
l ~bjNhk
)7X+T'?%
public void setSFileName(String value) |AosZeO_
{ ~Onj|w7
sFileName = value; 72i]`
} -|1H-[Y(
w@K4u{|
W|~Jl7hs8Q
public int getNSplitter() #=}dv8
{ 4blw9x N
return nSplitter; It5U=PU
} M lv
KOQiX?'
1\'?.
public void setNSplitter(int nCount) R1!F mZW8
{ C]X:@^Hy
nSplitter = nCount; "7w~0?}
} .,-,@ZK
} .2K4<UOAbm
a'NxsByG]s
"ITC P<+
/* ~RdD6V
**Utility.java '7'*+sgi$
*/ Mx-? &
package NetFox; ,H_b@$]n8
7m4gGkX#r
4yZ'+\ +I
public class Utility { s!lLdR[g
For`rfR
|E& Fe8
public Utility() g431+O0K1
{ \tpJ
PZT]H?
rP5&&Hso
} <>|&%gmz
DGs=.U-=e
//线程睡眠 4t C-msTf
public static void sleep(int nSecond) A-=B#UF
{ `.MY"g9
try{ ]"ZL<?3g
Thread.sleep(nSecond); .o27uB.
} c `[,>
catch(Exception e) V6c>1nZ
{ a{4Wg:
e.printStackTrace (); 9s#Q[\B!
} ^#6"d+lp
} &Zxo\[lP
|b BA0.yS
//日志 4qd =]i
public static void log(String sMsg) )td?t.4
{ #NoY}*
System.err.println(sMsg); )A@ }mIs"
} Ok0zgi
NmH1*w<A
g6s&nH`Z2
public static void log(int sMsg) )2nx5"
{ D.!ay>o0#
System.err.println(sMsg); 5B|&+7dCw
} A`5/u"]*D
} WfdM~k\
?{)sdJe
/Zzb7bHLK
/* IInsq
**TestMethod.java v+), uj
*/ 6w?l I
package NetFox; +qWrm|O]
~PTqR2x
gv6}GE
public class TestMethod { Zb \E!>V
vU4Gw4
0mb|JoE(
public TestMethod() tny^sG/'
{ ///xx/weblogic60b2_win.exe L+=pEk_
try{ \!*3bR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @Sik~Mm_h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $] gwaJ:
SiteFileFetch fileFetch = new SiteFileFetch(bean); p)x*uqSd
fileFetch.start(); H'2J!/V
} ,qj1"e
catch(Exception e){e.printStackTrace ();} n#US4&uT4A
3 L:s5
I^u$H&
} nDFF,ge;a#
ms(Z1ix^
o4[
public static void main(String[] args) +zl2|'
{ h/LlH9S:!
new TestMethod(); ^(Y}j8sj
} \68x]q[
} Dc1tND$X3g
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