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)); q OXL(
} m0#hG x
for(int i=0;i<nEndPos.length-1;i++) u(o@_6
{ 7dakj>JM
nEndPos = nStartPos[i+1]; C9nNziws
} z^b\hR
nEndPos[nEndPos.length-1] = nFileLength; x``!t>)O
} 1";~"p2(
} 6S&#8l
o _CVZ
y~dW=zO
//启动子线程 @%TQ/L^|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ECSC,oJ
for(int i=0;i<nStartPos.length;i++) K:Ap|F
{ [Ytia#Vv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YW'Y=*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _9-Ajv
nStartPos,nEndPos,i); ]I]dwi_g)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _<~05Eh
fileSplitterFetch.start(); '0=U+Egp
} 4 '+)9&g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~W#f,mf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $K iMu
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kQb0pfYs
nEndPos = " + nFileLength); *\`C!r
// fileSplitterFetch[nPos.length-1].start(); jsG9{/Ov3
[:k'VXL
_m&VdIPO
//等待子线程结束 zZRqb/20
//int count = 0; ysa"f+/
//是否结束while循环 6RF01z|~_
boolean breakWhile = false; ENmo^O#,u
e}?t[aK4#
P``hw=L
while(!bStop) y#MLxm
{ a=J?[qrx
write_nPos(); CVUDN2
Utility.sleep(500); A1@-;/H3
breakWhile = true; sDF J
YU"Am !
'L m `L<`
for(int i=0;i<nStartPos.length;i++) a} /Vu"
{ *p-Fn$7\n
if(!fileSplitterFetch.bDownOver) ]@f6O*&=
{ M&K@><6k,k
breakWhile = false; c`>\R<Z ]
break; :X!(^a;]
} Q?>#sN,
} i~.[iZf|
if(breakWhile) W@G[ gS\T
break; XXF9oy8
4 hj2rK'y
|Bn=$T]
//count++; -Z Z$ 1E
//if(count>4) Ntqc=z
// siteStop(); w(yU\ N
} Ao\Vh\rQkq
i`Yf|^;@2>
9,Mp/.T"\
System.err.println("文件下载结束！"); -r2cK{Hhp&
} 5bw]cv$i
catch(Exception e){e.printStackTrace ();} 9t[278B6
} Z^|C~lp;n
4A&e+kz&:R
6?lg 6a/eO
//获得文件长度 MT5A%|He
public long getFileSize() h<M7[p=
{ PHXP1)^}S
int nFileLength = -1; HB}gn2.1&
try{ 'f+NW&
URL url = new URL(siteInfoBean.getSSiteURL()); =LI:S|[4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v8m`jxII64
httpConnection.setRequestProperty("User-Agent","NetFox"); :'}@Al9=>
"k:=Y7Dx
$ KB
int responseCode=httpConnection.getResponseCode(); GKZN}bOm\
if(responseCode>=400) )MSZ2)(
{ .IgRY\?Q
processErrorCode(responseCode); n*<v]1
return -2; //-2 represent access is error L&kr{7q
} OX\$nQ\o
ZSB?Y1wG
~jN'J+_$
String sHeader; wfR&li{
j+kC-U;
6S1m<aH6
for(int i=1;;i++) ;hHi@Z9
{ MzkkcQLK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xgat-cy'DA
//Utility.log(in.readLine()); ab.tH$:<
sHeader=httpConnection.getHeaderFieldKey(i); P`(Mk6gE
if(sHeader!=null) fDh]tua
{ )h_8vO2
if(sHeader.equals("Content-Length")) TTZe$>f
{ pf&ag#nr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nlGHT
break; ]*N1t>fb
} 2eb1lJdS
} ZVih=Y-w
else +v7) 1y
break; Q@S-f:!
} eE(b4RCM
} cn`iX(ZgR
catch(IOException e){e.printStackTrace ();} UvJ;A
catch(Exception e){e.printStackTrace ();} w7TJv4_
FX}Gt=
B^v8,;jZT
Utility.log(nFileLength); /=:j9FF
]a'99^?\
p3(2?UO!
return nFileLength; b:W-l?
} g)"gw+ZFc
'b&yrBFD
aYn^)6^
//保存下载信息（文件指针位置） qv*7K@
private void write_nPos() jgv`>o%<W
{ hz:pbes
try{ u=x+J=AH
output = new DataOutputStream(new FileOutputStream(tmpFile)); YJV%a
output.writeInt(nStartPos.length); T{v>-xBRy
for(int i=0;i<nStartPos.length;i++) \ 0W!4D
{ p4!:]0c
// output.writeLong(nPos); &7e)O=
output.writeLong(fileSplitterFetch.nStartPos); ]=pR
output.writeLong(fileSplitterFetch.nEndPos); KqY["5p
} )!:sFa 1
output.close(); &ANP`=
} 58Xzup_"
catch(IOException e){e.printStackTrace ();} Qn@Pd*DR
catch(Exception e){e.printStackTrace ();} E H:T
} nI.x
Pz*_)N}j >
dP?Ge}
//读取保存的下载信息（文件指针位置） \_V-A f{6
private void read_nPos() !E8X~DJ
{ @mP]*$00
try{ *iBTI+"]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O/s$SX%g
int nCount = input.readInt(); ^zzP.
nStartPos = new long[nCount]; JF&$t}
nEndPos = new long[nCount]; }o4N<%/+
for(int i=0;i<nStartPos.length;i++) EP'h@zdz
{ #'D" 'B
nStartPos = input.readLong(); g- AHdYJ
nEndPos = input.readLong(); TxjYrzC
} 9vUO*D
input.close(); tz4 ]qOH8
} ^bg2[FV
catch(IOException e){e.printStackTrace ();} #} ~qqJ G2
catch(Exception e){e.printStackTrace ();} d@`M CchCB
} ^k5ll=}
%VYAd)gC
{;toI
private void processErrorCode(int nErrorCode) CYYkzcc^
{ ;<yd^Xs
System.err.println("Error Code : " + nErrorCode); Y}#h5\
} EVp,Q"V]
S5~VD?O,
Ya>oCr}K
//停止文件下载 *.L81er5~
public void siteStop() kB?al#`
{ '!l1=cZD
bStop = true; Ox#\M0Wn$3
for(int i=0;i<nStartPos.length;i++) JJ;[,
fileSplitterFetch.splitterStop(); bM8If"
u6>?AW1~
^O^l(e!3
} ,'[<bP'%_
} ,0x y\u
//负责部分文件的抓取 :Y9NLbv
**FileSplitterFetch.java zSo)k~&[3
*/ q_-7i
package NetFox; $)3%U?AP
UnI48Y
aLIBD'z
import java.io.*; 9U$EJN_G
import java.net.*; O_Oj|'bBC
>3z5ww
V(Ub!n:j
public class FileSplitterFetch extends Thread { <n]x#0p
W 4F\}A
z5)s/;Sc
String sURL; //File URL v\p;SwI
long nStartPos; //File Snippet Start Position H54R8O$
long nEndPos; //File Snippet End Position ,o)d3g-&g
int nThreadID; //Thread's ID ]T%rjsN
boolean bDownOver = false; //Downing is over sQMFpIrr
boolean bStop = false; //Stop identical v{}#?=I5
FileAccessI fileAccessI = null; //File Access interface cJ54s}
zbq@pj)Qu
G "73=8d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aH^RoG}
{ dd]/.Z
this.sURL = sURL; cReB~wk
this.nStartPos = nStart; 4'0Dr++
this.nEndPos = nEnd; ki85!k=Q2
nThreadID = id; S#+h$UVh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 br|;'i%(
} ?M[ A7?
:_O%/k1\@
O} f80K
public void run() )E~79!
{ \EVBwE,
while(nStartPos < nEndPos && !bStop) j$+nKc$
{ 7}X[ 4("bB
t+eVR8
1Z9qjV%^
try{ b j'Xg
URL url = new URL(sURL); V3"=w&2]K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7AObC4 g
httpConnection.setRequestProperty("User-Agent","NetFox"); M%@!cW
String sProperty = "bytes="+nStartPos+"-"; }`@728E
httpConnection.setRequestProperty("RANGE",sProperty); C+TI]{t
Utility.log(sProperty); }I :OsAw
m}X`> aD/
.FLy;_f+
InputStream input = httpConnection.getInputStream(); yxH ( c
//logResponseHead(httpConnection); zRyuq1Zyc,
p>upA)W]
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byte[] b = new byte[1024]; h@[R6G|
int nRead; #W|'1 OX4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )'~6HO8Z
{ 9M:O0)s
nStartPos += fileAccessI.write(b,0,nRead); C_7+a@?B
//if(nThreadID == 1) % ClHCoyA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |>#{[wko
} THS.GvT9[
GSRVe/[
2K3{hxB
Utility.log("Thread " + nThreadID + " is over!"); =17t- [
bDownOver = true; sIxTG y.
//nPos = fileAccessI.write (b,0,nRead); +1D+]*t_?[
} 7:2WgLo
catch(Exception e){e.printStackTrace ();} ^3UGV*Ypk
} HbxL:~:}J
} jJ5W>Q1mK$
7D;cw\ |
RR]CW
//打印回应的头信息 {o>j6RS\
public void logResponseHead(HttpURLConnection con) @g&ct>@y
{ ^Gqt+K%
for(int i=1;;i++) 1 =M ?GDc
{ r_-_a(1R:
String header=con.getHeaderFieldKey(i); cj1cZ-
if(header!=null) MZT23[+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3yB!M
Utility.log(header+" : "+con.getHeaderField(header)); *exS6@N]
else E/%9jDTQ
break; ;ShJi
} 9T*v9d
} 3G(miP6
G{6;>8h
c1E'$- K@
public void splitterStop() Np"exFqN k
{ Yj6*NZ*
bStop = true; SN1}xR$
} [rSR:V?"a
(aH'h1,G
C,v(:ZE$J7
} !0vG|C;'
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@ < Q|5
/* `1bv@yzq
**FileAccess.java $7rq3y
*//文件访问(定位，写) a_'2V;
package NetFox; U G~ba
import java.io.*; :{q<{^c
w tiny,6
5 4L\Jx
public class FileAccessI implements Serializable{ CnG+Mc^
):b$xNn
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SAyufLEv,
RandomAccessFile oSavedFile; {M^3m5.^
long nPos; F!]lU`z)=
2AO~HxF
!BOY@$Y
public FileAccessI() throws IOException <w)r`D6
{ E: $P=%b
this("",0); d\jPdA.a=
} ^$'z!+QRM
0a-0Y&lQm
2C9V|[U,
public FileAccessI(String sName,long nPos) throws IOException u (em&M
{ k{Me[B
oSavedFile = new RandomAccessFile(sName,"rw"); b"vv>Q~U
this.nPos = nPos; 3v5%y'
oSavedFile.seek(nPos); nh!a)]c[
} SU/BQ3
y&?6FY
4'!c*@Y
public synchronized int write(byte[] b,int nStart,int nLen) q@nP}Pv&5
{ / ;,Md,p
int n = -1; 2&^]k`Aj6D
try{ a*ushB
oSavedFile.write(b,nStart,nLen); g!+|I
n = nLen; y*tZ !m2Gg
} xx{PespNt
catch(IOException e) PGLplXb#[S
{ 32/MkuY^u
e.printStackTrace (); TiO"xMX
} jO1r)hw N>
:F{:Z*Fi0
P#XID 2;
return n; "F.;Dv9V[0
} 83Q4On
SVB\
m6[0Kws&
} TTt#a6eJ
NR5oIKP?
or';A'k
/* I/L_@X<*r
**SiteInfoBean.java Bhp-jq'!B
*/ Htgx`N|
package NetFox; -< &D
f=mZu1(FZ
|(q9"
public class SiteInfoBean { |qmu_x\
'4|-9M3f
I^8"{J.Q)[
private String sSiteURL; //Site's URL "vyNxZE
private String sFilePath; //Saved File's Path (KF=On;=Y
private String sFileName; //Saved File's Name '-"/ =j&d[
private int nSplitter; //Count of Splited Downloading File 8@2OJ=`[
,Qnd3[2[
5&q8g;XiEM
public SiteInfoBean() Ou1JIxZ)|
{//nSplitter的缺省值为5 [3--(#R\}?
//default value of nSplitter is 5 JAX*hGhkh
this("","","",5); V*iH}Y?^p
} <-D0u?8
mM-8+H?~b
<RG|Dx[:=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?Vdia:
{ @Q/-s9b
sSiteURL= sURL; q11>f
sFilePath = sPath; -cSP_1
sFileName = sName; vc+ARgvH+
this.nSplitter = nSpiltter; 45MLt5^|
PX n;C/
Bxfc}vC.
} }woo%N P
7e#?e+5+A
HsHB!mQV
public String getSSiteURL() HOE_S!N
{ 6^"=dn6K
return sSiteURL; 0Emr<n
} Ie`13 L2
PV4(hj
r;Gi+Ca5
public void setSSiteURL(String value) I9mvte
{ l:<?{)N`
sSiteURL = value; 6u`)QUmItg
} YJ;j x0
k=B]&F
R@6zGZ1
public String getSFilePath() (''M{n
{ 8rMX9qTO@
return sFilePath; Rx);7j/5
} -"h;uDz|z
L.2/*H#
4)"n RjGg
public void setSFilePath(String value) fD07VBS yl
{ 1}:bqI.<W
sFilePath = value; f3Hed
} bD[!/'4eJ
HN.3
L\&<sy"H
public String getSFileName() @1 U&UH
{ &znQ;NH#
return sFileName; +S R+x/?z
} :w<V
v}tag#f5>?
%ix)8+Eb
public void setSFileName(String value) |d*&y#kV
{ 4&_NJ\
sFileName = value; mXUGe:e8
} phn9:{TI
-|Y(V5]
*r=:y{!Yd
public int getNSplitter() H~+l7OhV
{ ~<k,#^"}X
return nSplitter; ( @3\`\X
} >layJt
MH{GR)ng:9
)@L'wW
public void setNSplitter(int nCount) B';6r4I-
{ 2A\,-*pc
nSplitter = nCount; 5Pd"h S
} *_KFW@bC:
} u6_@.a}
sz)oZPu|
7\9>a
/* &CIVL#];e
**Utility.java qR8u$2}NY
*/ 3Ezy %7
package NetFox; sPpsq
e+j)~RBnu3
#Ap;_XcKw
public class Utility { ]_8qn'7
N @#c,,
IR-dU<<9O
public Utility() pFm=y#!t
{ Y= ]dvc
8?i7U<CB
~O]]N;>72"
} q~59F@
s-RQMK}H
//线程睡眠 *$"gaXI
public static void sleep(int nSecond) (lGaPMEU}
{ gi-Yqco
try{ ZWm8*}3]7_
Thread.sleep(nSecond); sj8~?O
} qBQ`~4s
catch(Exception e) `AkIK*
{ Pf$pt
e.printStackTrace (); sU"}-de
} M#4QQ} F.
} 8NU`^L:1
!bD@aVf?5
//日志 RC^9HuR&
public static void log(String sMsg) wBInq~K_
{ oP2fX_v1x
System.err.println(sMsg); .iQT5c
} U^.4Hy&D
%',F
_6k*'aT~FK
public static void log(int sMsg) xEltwuDd?
{ yCXrVN:`,
System.err.println(sMsg); F*Z=<]<+
} 8`]=C~G
} %+F"QI1~0
.,i(2^
9M /SH$Qy
/* ?+t1ME|
**TestMethod.java 5PIZh<
*/ )%X;^(zKM
package NetFox; S/`%Q2za4
YxGcFjJ
3loY qeP
public class TestMethod { e8EfQ1 Ar
]O TH"*j
<N(oDaU
public TestMethod() PU {uE[
{ ///xx/weblogic60b2_win.exe $2MAZGJV
try{ ow/57P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6QNs\Ucb+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T'#!~GpB
SiteFileFetch fileFetch = new SiteFileFetch(bean); M|[ZpM+
fileFetch.start(); vZ#!uU^a:
} :+%Zh@u\
catch(Exception e){e.printStackTrace ();} -z:&*=
hKlZi!4J
e.o;eD}"
} }#v{`Sn%^C
3I|3wQ&#(
%vO<9fE|1
public static void main(String[] args) ;50_0Mv;(:
{ xAwf49N~
new TestMethod(); .9|uQEL
} gLL\F1|0x
} Y& ] 8 {
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