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)); B&RgUIrFoY
} #OVf2 "
for(int i=0;i<nEndPos.length-1;i++) ::A]p@
{ l:H}Y3_I
nEndPos = nStartPos[i+1]; Ff@Cs0R
} and)>$)|
nEndPos[nEndPos.length-1] = nFileLength; c;pv< lX'
} 6_h'0~3?`
} O6$d@r;EK]
fG*366W
m6oaO9"K
//启动子线程 uRfFPOYH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dy^zOqc
for(int i=0;i<nStartPos.length;i++) ~kW[d1'c
{ +>wBGVvS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FOx&'dH%@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O$,MdhyXC
nStartPos,nEndPos,i); >|@i8?|E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~i y]X:U
fileSplitterFetch.start(); NLA/XZ
} W6 U**ir.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [:(^n0%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w `0m[*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o0'!u
nEndPos = " + nFileLength); Au-h#YV
// fileSplitterFetch[nPos.length-1].start(); (+ibT;!]
>2w^dI2
:7-2^7z)
//等待子线程结束 `gFE/i18
//int count = 0; ~'<ca<Go|
//是否结束while循环 o)pso\;
boolean breakWhile = false; N\9Wxz$
<|MF\D'
QZs ]'*=#
while(!bStop) a{FCg%vD)
{ =~f\m:Y
write_nPos(); }hy, }2(8
Utility.sleep(500); mjtmN0^SR
breakWhile = true; e7^B3FOx
kg^VzNX
qu:nV"~_
for(int i=0;i<nStartPos.length;i++) F+3}Gkn
{ Lradyo44u\
if(!fileSplitterFetch.bDownOver) |kXx9vGq@
{ c/Ykk7T9--
breakWhile = false; z[`OYwsW
break; -]K9sy)I
} R#x~f
} ',Q|g^rF]
if(breakWhile) 86AZ)UP2D
break; ^Voi4;
{5, ]7=]
_^5OoE"}!
//count++; gx',~
//if(count>4) p2/Pj)2
// siteStop(); TC+L\7
} ZcLW8L
-)p S\$GC
rV0X*[]J>
System.err.println("文件下载结束！"); L H8iHB
} ;0c -+,
catch(Exception e){e.printStackTrace ();} 0<";9qN)6
} (q]_&%yW
?8GggJC
p&nPzZQL(
//获得文件长度 Oe["4C
public long getFileSize() Fb0r(vQ^
{ /5$;W'I
int nFileLength = -1; !RD<"
try{ 3\B28m
URL url = new URL(siteInfoBean.getSSiteURL()); 4ru-qF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;qN;oSK
httpConnection.setRequestProperty("User-Agent","NetFox"); cfP9b8JG
!|#W,9
?~p]Ey}~9
int responseCode=httpConnection.getResponseCode(); c&GVIrJ
if(responseCode>=400) P<5v\\
{ `UK'IN.il
processErrorCode(responseCode); ]9P2v X
return -2; //-2 represent access is error z?DI4O#Up
} ^.HvuG},O
:+qd>;yf#
7H l>UX,|
String sHeader; -$2a@K,i
,|RN?1?U
L]kd.JJvy
for(int i=1;;i++) G8t9Lx
{ !w;oVPNg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R0A|}Ee*
//Utility.log(in.readLine()); psFY=^69o
sHeader=httpConnection.getHeaderFieldKey(i); }83a^E9L
if(sHeader!=null) ^kO+NH40
{ +>}LT_
if(sHeader.equals("Content-Length")) ``?79MJ5
{ Nm7YH@x*o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z)^1~!w0
break; @?vC4+'
} PptVneujI
} @$aGVEcU$
else LGdM40
break; x=M%QFe
} sW^e D;
} J{!U;r!6
catch(IOException e){e.printStackTrace ();} |Fi{]9(G2
catch(Exception e){e.printStackTrace ();} M(/ATOJ(
W2Ik!wEe&
(xdC'@&
Utility.log(nFileLength); e1OGGF%En
n(h9I'V8)F
.US=fWyrb
return nFileLength; [2$mo;E?
} ?`lD|~
v6C$Y+5~
nmuzTFs=
//保存下载信息（文件指针位置） 2Wn*J[5
private void write_nPos() K'_qi8Z
{ C==yl"w
try{ v8} vk]b
output = new DataOutputStream(new FileOutputStream(tmpFile)); .sCj3sX*
output.writeInt(nStartPos.length); omMOA
for(int i=0;i<nStartPos.length;i++) Cvp!(<<gK
{ ('k9XcTPP
// output.writeLong(nPos); q S qS@+p
output.writeLong(fileSplitterFetch.nStartPos); xWnOOE$i
output.writeLong(fileSplitterFetch.nEndPos); +6`+Q2qi
} fg)VO6Wo&
output.close(); PS}'LhZ
} KcvstC`
catch(IOException e){e.printStackTrace ();} HSk_'g(\0
catch(Exception e){e.printStackTrace ();} xfa-
} :o 8XG
S54q?sb_
IE|? &O
//读取保存的下载信息（文件指针位置） 2O 2HmL
private void read_nPos() Xwo%DZKN
{ ;=p3L<~c`K
try{ ![i)_XO
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ZfMs6`Wv 1
int nCount = input.readInt(); KTq+JT u
nStartPos = new long[nCount]; -|GKtZ]}
nEndPos = new long[nCount]; oo\7\b#Jx
for(int i=0;i<nStartPos.length;i++) g\% Z+Dc
{ AU1U?En
nStartPos = input.readLong(); E|vXM"zFl
nEndPos = input.readLong(); 9Vru,7g
} U4.$o]58
input.close(); 4`B3Kt`o
} _a#k3r
catch(IOException e){e.printStackTrace ();} } J[Z)u
catch(Exception e){e.printStackTrace ();} 4_`(c1oA
} >qz#&
Q+oV? S3{
JC MUK<CG
private void processErrorCode(int nErrorCode) V3>tW,z
{ Z)}UCi+/".
System.err.println("Error Code : " + nErrorCode); zM,r0Z
} C-@[=
.* )e24`
.P <3+
//停止文件下载 *`q?`#1&&.
public void siteStop() ", p5}}/
{ %tMx48'N
bStop = true; f"*k>=ETI
for(int i=0;i<nStartPos.length;i++) EE^x34&=
fileSplitterFetch.splitterStop(); o! l Ykud
9Pb6Z}
L#",.x
} :r(dMU3%
} <5?pa3
//负责部分文件的抓取 .g3=L
**FileSplitterFetch.java aeISb83Y|
*/ }T0O~c{$i
package NetFox; PY;tu#W!%
<.mH-Y5i
9Ta0Li
import java.io.*; Sbl=U
import java.net.*; n)~*BpL3
u0GHcpOm
`BQv;NtP
public class FileSplitterFetch extends Thread { Vr|e(e.%
u&w})`+u5
"M, 1ElQ
String sURL; //File URL pI:,Lt1B
long nStartPos; //File Snippet Start Position .faf!3d
long nEndPos; //File Snippet End Position \{}dn,?Fv
int nThreadID; //Thread's ID N+ak{3
boolean bDownOver = false; //Downing is over 8qqN0"{,
boolean bStop = false; //Stop identical vTgx7gP
FileAccessI fileAccessI = null; //File Access interface _6Y+E"@zs
lXg5UrW
P}]o$nWT
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException xbBqR_H_
{ cGiL9|k
this.sURL = sURL; 5f{P% x(
this.nStartPos = nStart; :\vs kk),
this.nEndPos = nEnd; sO` oapy
nThreadID = id; n>?D-)g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +SR{FF
} 1X[^^p~^
d=n@#|3
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public void run() n m<?oI*\
{ <|3%}?
while(nStartPos < nEndPos && !bStop) P`ou:M{8
{ .%s U)$bH
=#/Kg_RKL
m`9nDiV
try{ J*[@M*R;&
URL url = new URL(sURL); 4Wp5[(bg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'L7qf'RV
httpConnection.setRequestProperty("User-Agent","NetFox"); qXg&E}]:=
String sProperty = "bytes="+nStartPos+"-"; 'S1u@p,q
httpConnection.setRequestProperty("RANGE",sProperty); G[\TbPh
Utility.log(sProperty); #]x3(}3W
VJ=>2'I
kDE-GX"Y
InputStream input = httpConnection.getInputStream(); ~\mh\a&
//logResponseHead(httpConnection); ujRXAN@mC
+4.s4&f)
#D4
byte[] b = new byte[1024]; odSPl{.>d
int nRead; G0{Z@CvO'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >UMxlvTg&
{ 4SZ,X^]I>
nStartPos += fileAccessI.write(b,0,nRead); B ytx.[zbX
//if(nThreadID == 1) {Q3OT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QJ3#~GYNr
} P{--R\
9H/>M4RT
f4h~c
Utility.log("Thread " + nThreadID + " is over!"); R7/S SuG6\
bDownOver = true; 4%^z=%
//nPos = fileAccessI.write (b,0,nRead); {_Wrs.a'8
} 755,=U8'wi
catch(Exception e){e.printStackTrace ();} n&njSj/
} W48RZghmx
} RkE)2q[5
Ln4]uqMG.
_Xt/U>N
//打印回应的头信息 16zReI(
public void logResponseHead(HttpURLConnection con) V9,<>
{ 8i154#l+\
for(int i=1;;i++) dMH_:jb
{ GLn=*Dh#
String header=con.getHeaderFieldKey(i); r*+~(83k
if(header!=null) .`}TND~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9h amxi
Utility.log(header+" : "+con.getHeaderField(header)); q1T)H2S
else ->rqr#
break; {5~h
} F(yR\)!C
} SO=gG 2E
xgcxA:
Cgx:6TRS
public void splitterStop() k1<^Ept
{ `Pvi+:6\Y
bStop = true; |Dn Zk3M,
} ZC N}iQu4
[(heE
%dzt'uz
} TP rq:"K
nzC *mPX8
uQIPnd(V
/* ?>}p'{I
**FileAccess.java Z*m^K%qJ
*//文件访问(定位，写) YGJ!!(~r
package NetFox; hSm?Z!+
import java.io.*; Hz.i$L0}
[kg?q5F)
2y - QH
public class FileAccessI implements Serializable{ )X0=z1$
uu.X>agg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '4 *0Pw
RandomAccessFile oSavedFile; <= o<lRU
long nPos; ,c&u\W=p
|9jK-F6
x95s%29RS
public FileAccessI() throws IOException t`Kpbfk
{ @3.Z>KONx
this("",0); uge r:cD
} 9\4x<*
AioW*`[WjA
ij$NTY=u
public FileAccessI(String sName,long nPos) throws IOException ubM1Qr
{ ZaYiby@Ci
oSavedFile = new RandomAccessFile(sName,"rw"); 2Mt$Dah
this.nPos = nPos; ,Z~`aHhr
oSavedFile.seek(nPos); !T,<p
} x4I!f)8Q
tnJ7m8JmC
O2Qmz=%
public synchronized int write(byte[] b,int nStart,int nLen) MJ JC6:
{ SaXt"Ju,AH
int n = -1; EHwb?{
try{ klUV&O+=%
oSavedFile.write(b,nStart,nLen); ^ 8}P_
n = nLen; K1 "HJsj
} yMNJHiE/
catch(IOException e) K,g6y#1"
{ M{J>yN
e.printStackTrace (); 9<u&27.
} h-96 2(LG
>%tP"x{
:^]Po$fl
return n; $5i\D rs
} ~^2w)-N
,/?J!W@m
oJTEN}fL
} Ak?9a_f
M2Nh3ijr
KR( apO
/* PEI$1,z
**SiteInfoBean.java {N2GRF~c-y
*/ @@D/&}#F
package NetFox; *|y'%y
LA6XTgcu
mW"e
public class SiteInfoBean { L ci?
-dM~3'
B&_:20^y~
private String sSiteURL; //Site's URL \^(#b,k#
private String sFilePath; //Saved File's Path }rJqMZ]w
private String sFileName; //Saved File's Name 6|EOB~|
private int nSplitter; //Count of Splited Downloading File i3)3.WK^
jwk+&S
Tv|'6P
public SiteInfoBean() }ekNZNcuM
{//nSplitter的缺省值为5 k M/:n
//default value of nSplitter is 5 0kUhz\"R:q
this("","","",5); &`m.]RV
} P'Y(f!%
u0wu\
j EbmW*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1|p\rHGd
{ ;l;jTb^l
sSiteURL= sURL; "Erphn
sFilePath = sPath; NuO@Nr
sFileName = sName; DNmC
this.nSplitter = nSpiltter; oc"p5Y3,Os
Zna6-0o
~;HASHu
} Kh3i.gm7g
[\ku,yd%0
\;-Yz
public String getSSiteURL() niS\0ZA
{ YMw,C:a4
return sSiteURL; 4m\Cc_:jO
} @>z.chM;
F[coa5
eYv^cbO@:
public void setSSiteURL(String value) q,sO<1wAT\
{ D!* SA
sSiteURL = value; CRo@+p10
} QO$18MBcc
<@M5 C-hH
bzG vnaTt
public String getSFilePath() J)g +I
{ /[Nkk)8-
return sFilePath; "I=Lbh-`
} -d?<t}a
):Fg {7b]n
Wgf f+7k
public void setSFilePath(String value) 9vi+[3s/=;
{ _&HFKpHQ
sFilePath = value; vmgd
} F~v0CBcAL
F4=X(P_6
Ne9VRM P
public String getSFileName() %5L~&W}^"
{ l%V+]skS
return sFileName; ."Pn[$'.
} Ks3YrKk;p
"U9e)a0v
~e|E5[-i
public void setSFileName(String value) <YCjo[(~
{ GB+$ed5@<
sFileName = value; ZXhNn<
} vmxS^_I
^E, #}cW
l )r^|9{
public int getNSplitter() 1^AQLOiRE1
{ yu#m6K
return nSplitter; E.C=VfBW
} 1&h\\&ic
nVpDjUpN
"wVisL2+.
public void setNSplitter(int nCount) )[99SM
{ Z2;~{$&M+
nSplitter = nCount; ,wr5DQ
} B|syb!g
} Bz{"K
/?>W\bP<
f3;[ZS
/* -R9{Ak
**Utility.java UnDX .W*2
*/ -4Q\FLC'k
package NetFox; fda2dY;
Y;\@ 5TgQ,
a{e1g93}
public class Utility { ZkibfVwe
1< b~="
mJ8EiRSE
public Utility() HII@Ed f?
{ uEsF 8
zW?=^bE
'Q*.[aJt
} lNe5{'OrO
"Z';nmv'N
//线程睡眠 f. h3:_r
public static void sleep(int nSecond) $U&p&pgH=W
{ .' v$PEy
try{ Gp_flGdGQ
Thread.sleep(nSecond); i1{)\/f3
} 4<EC50@.
catch(Exception e) Ga^:y=m
{ "6~+-_:
e.printStackTrace (); A{3nz DLI
} ]:#W$9,WL
} h1Y^+A_
tPk>hzW
//日志 ^S|}<6~6b
public static void log(String sMsg) p=[I;U-#H
{ Eb'M< ZY
System.err.println(sMsg); t@2MEo
} 5HB*
5rtE/{A
PTQN.[bBh
public static void log(int sMsg) =OrVaZ0
{ DLq'V.M:
System.err.println(sMsg); .5~3D97X&
} -Zg.o$
} )*}?EI4.
@]]\r.DG
A)#Fyde
/* eOb)uIF
**TestMethod.java P-Gp^JX8
*/ H ~<.2b
package NetFox; F${}n1D
F)aF.'$-/
R-k~\vCW
public class TestMethod { l?X)]1
P#:nXc$
9*s:Vff{
public TestMethod() +wEsfYW
{ ///xx/weblogic60b2_win.exe Tj2pEOu
try{ ^%1u3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a!j{A?7Kw.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z0 c|;
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;b|=osyT\
fileFetch.start(); n"I{aJ]K
} X4k|k>
catch(Exception e){e.printStackTrace ();} +wGvYr
ws;|fY
M>*xbBl
} b-#oE{(\'
$}H,g}@0
nbv}Q-C
public static void main(String[] args) z wn#E
{ :@Ml-ZE
new TestMethod(); JGYJ;j{E]
} gP ^A
} I!Fd~g9I4
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